american society of civil engineers instituted transactions paper no. the new york tunnel extension of the pennsylvania railroad. the north river division. by charles m. jacobs, m. am. soc. c. e. these observations are written with the purpose of outlining briefly, as far as the writer was concerned, the evolution of the scheme of bringing the pennsylvania railroad and the long island railroad into new york city, and also, as chief engineer of the north river division of the new york tunnel extension of the pennsylvania railroad, to record in a general way some of the leading features of the work on this division, which is that portion of the work extending from the east line of ninth avenue, new york city, to the hackensack portal on the westerly side of the palisades, as an introduction to the papers by the chief assistant engineer and the resident engineers describing in detail the work as constructed. it may be stated that, since shortly after the year , when the pennsylvania railroad system was extended to new york harbor through the lease of the new jersey lines, the officers of that company have been desirous of reaching new york city by direct rail connection. the writer's first connection with the tunneling of the north river was early in , when he was consulted by the late austin corbin, president of the long island railroad company and the philadelphia and reading railroad company, as to the feasibility of connecting the long island railroad with the philadelphia and reading railroad (or with the central railroad of new jersey, which was the new york connection of the reading) by a tunnel from the foot of atlantic avenue, brooklyn, under the battery and new york city, and directly across the north river to the terminal of the central railroad of new jersey. surveys, borings, and thorough investigations were made, and the metropolitan underground railroad company was incorporated in the state of new york to construct this railroad. mr. corbin, however, was aware that, in the transportation problem he had in hand, the central railroad of new jersey and the philadelphia and reading railroad were not as important factors as the pennsylvania railroad, and, in consequence, he abandoned the scheme for a tunnel to the central railroad of new jersey for a line direct to the pennsylvania railroad terminal in jersey city. meantime, the pennsylvania railroad company, as a result of its investigation of the matter, in june, , thought that the most feasible project seemed to be to build tunnels for rapid transit passenger service from its jersey city station to the lower part of new york, connecting there with the rapid transit systems of that city, and also extending under new york on the line of cortlandt street, with stations and passenger lifts at the main streets and elevated railroads. the late a. j. cassatt, then a director of the pennsylvania railroad company, and previous thereto as general manager and vice-president (and later as president) of that company, was deeply interested in obtaining an entrance into new york city, but was not satisfied with the proposed rapid transit passenger tunnels which required the termination of the pennsylvania railroad trains at its jersey city station. therefore, upon his request, in september of the same year, another study and report was made by joseph t. richards, m. am. soc. c. e., then engineer of maintenance of way of the pennsylvania railroad, on a route beginning in new york city at th street and park avenue on the high ground of murray hill, thence crossing the east river on a bridge, and passing around brooklyn to bay ridge, thence under the lower bay or narrows to staten island and across to the mainland, reaching the new york division of the pennsylvania railroad at some point between rahway and metuchen. mr. cassatt also had in mind at that time a connection with the new england railroad, then independent, but now part of the new york, new haven, and hartford railroad system, by means of the long island railroad, and a tunnel under the east river, which in later years, as the result of further consideration of the situation, has been covered by the proposed new york connecting railroad with a bridge across the east river and over ward's and randall's islands. as a result of these investigations, the late george d. roberts, who was then president of the pennsylvania railroad company, authorized an expenditure of about $ , for soundings to determine the nature of the strata for tunneling under water. these soundings were carefully made by mr. richards with a diamond drill, bringing up the actual core of all rock found in crossing the waters of new york bay from the west to the east side and extending from the narrows to the jersey city station of the pennsylvania railroad. after these investigations had been made, early in , mr. roberts expressed himself as being favorable to the undertaking, with the definite limitation that the tunnels must be for small cars doing local suburban business, and for the transfer of pennsylvania railroad passengers to and from new york, brooklyn, and jersey city, and not in any way to be tunnels for standard steam equipment, the expense for terminals and the prohibited use of coal for fuel in such tunnels not warranting any broader consideration. under such instructions, the interests of the pennsylvania railroad company for effecting a physical entrance into new york city in that year were turned over to samuel rea, m. am. soc. c. e., then assistant to the president of that company, who has been identified with the investigations, and the progress and construction of this work since that time, mr. cassatt also working in conjunction with him on the plans then and since considered by the pennsylvania railroad management. on october th, , mr. rea, under special direction of president roberts, made an extended investigation of the various routes which had then been projected for extending the system into new york city by rail or transport, and reported to mr. roberts that, in his opinion, because of the limitation of the tunnel scheme to rapid transit trains and the consequent transfer of passengers and traffic carried in passenger trains, and because of the drawbacks caused by the use of steam locomotives in full-sized tunnels, and the objection to cable traction or any system of transportation which had not then stood the test of years of practical service, the plan of the north river bridge for reaching new york city and establishing a terminus therein was the best that had been evolved up to that time. the plan provided a direct rail entrance into new york city for all railroads reaching the west side of the hudson river, and also for the new york central and hudson river railroad, as well as adequate station facilities in that city. this bridge would have had one clear span of , ft. between pier heads, landing on the new york side at the foot of west d street, and thence the line would have passed diagonally to the terminus at sixth avenue and th street. the location of the terminus was subsequently changed to the vicinity of seventh avenue and th street. the bridge was designed with three decks: the first or lower deck was to accommodate eight steam railroad tracks; the second was to have six tracks, four of which could be assigned for rapid transit trains operating with electric power, and the other two for steam railroad trains; the third deck, reached by elevators, was to be a promenade extending from anchorage to anchorage. a connection with the eleventh avenue tracks of the new york central and hudson river railroad was to bring the trains of that road into the union station. the bridge company had a federal charter--granted in --with broad powers. gustav lindenthal, m. am. soc. c. e., was chief engineer, and he and mr. rea were corporators and among its early promoters. the pennsylvania railroad management looked with favor on its construction at that time, as subaqueous tunnels, with standard railroad equipment with steam traction, were not regarded as a final or attractive solution of the problem, from the standpoint of the management, and at a subsequent period the pennsylvania railroad company agreed to use the north river bridge provided the other roads reaching the west bank of the hudson river would join. these roads, however, did not avail themselves of the opportunity which in its broadest scope was laid before them in , after the board of directors of the pennsylvania railroad company had approved the scheme at the instance of mr. cassatt. the scheme of mr. corbin for a subway connection, between flatbush avenue and the jersey city station of the pennsylvania railroad, for local transit, took form in , and, jointly with the pennsylvania interests, railroad companies were incorporated in the respective states to build a tunnel from under the jersey city station, under the hudson river to cortlandt street, new york city, thence under maiden lane, the east river, and pineapple and fulton streets, brooklyn, to a location at or near flatbush and atlantic avenues. on may th, , these companies were merged into the brooklyn, new york and jersey city terminal railroad company, and estimates and reports on the construction were made ready by the writer in association with mr. rea, pending application for the franchises. the panic of , occurring about that time, checked further progress on this scheme, and, before it could be revived again, other important projects for reaching new york city were given consideration. that part of mr. corbin's plan contemplating a subway under atlantic avenue in brooklyn to the present flatbush avenue terminal was not a new idea, as a tunnel had been built in and operated under a portion of atlantic avenue, but later it was filled up. plate iv, reproduced from a crayon sketch which was the property of the late william h. baldwin, jr., is a view of this tunnel. in conjunction with schemes for river tunnels, complete plans for rapid transit subways for new york city, very much on the line of the present rapid transit subways, were also prepared for mr. corbin by the writer. these plans provided a system of deep tunnels in rock, entirely below the plane of quicksand, and at the battery the lines were to connect directly into the tunnels to long island and new jersey, respectively, and the stations throughout, where the rock was at a deep level, were to be fitted with elevators, grouped as suggested in plate v, using private property on each side of the street at station locations--one side for north-bound and the other side for south-bound traffic. these plans were submitted to the first rapid transit commission, and, after long consideration, were rejected by that commission because they provided for the construction of the tunnels by a private company, notwithstanding mr. corbin gave the commission assurances of ample financial means to carry the work to completion. during the years - mr. corbin was convinced that it was necessary to get better facilities for handling the baggage and express matter of the long island railroad and the long island express company across the east river between long island city and new york city, and he instructed the writer to investigate and report on the feasibility of building a tunnel, along the lines of the east river gas tunnels, then nearly completed, between the foot of east th street, new york city, and the long island city station of the long island railroad. in an investigation was made for such a tunnel, to be of similar size to the east river gas tunnel ( by ft.), solely for the purpose of handling baggage and express matter. investigation was made and estimates prepared, but the cost was considered to be prohibitive in view of the possible earnings solely from the handling of baggage and express, and the matter was not considered further. [illustration: plate iv.--tunnel under part of atlantic avenue, brooklyn. (from a crayon sketch.)] while mr. corbin was deeply interested in the down-town river tunnels, the up-town situation was of great importance to the long island railroad, and, having allied himself with mr. charles pratt, they took up generally the franchise owned by dr. thomas rainey for a bridge over blackwell's island. mr. corbin became interested with dr. rainey in , and the actual construction proceeded on this bridge. the design provided for four railroad tracks, besides highways for tracks, pedestrians, etc., with a terminal station at third avenue and th street, new york city, which, under the franchise, was the limit to which the railroad could proceed. at this period there were two projects for bridging the hudson or north river: the new york and new jersey bridge company at about th street, and the north river bridge company at d street, as hereinbefore described. several studies were made by the writer, with the idea of making a rail connection between the long island "rainey" bridge and a bridge over the north river. an overhead structure connection was prohibitory, as no franchise could be obtained to cross fifth avenue with an overhead structure. sketches were prepared for a subway construction to connect with the bridges, but a final plan was not worked out. the failure to carry out the joint undertaking with the pennsylvania railroad company in led mr. corbin to revive the scheme of extending the long island railroad from flatbush avenue, brooklyn, to new york city, therefore consideration was given to a relocation of the route for mr. corbin during the early months of , the idea being that the entire up-town outlet for the long island railroad would be by blackwell's island bridge, and the tunnel project would give the down-town outlet. at this time a commission had been appointed by the legislature to investigate the conditions on atlantic avenue, brooklyn, and evolve some scheme for the elimination of grade crossings on that avenue. early in plans were prepared and presented to this commission; first, for a subway from flatbush avenue terminal for the entire distance to the limits of the city of brooklyn at eldert's lane; second, for a subway from the flatbush avenue terminal to east new york, manhattan crossing, the railroad to remain as it previously existed at grade through the th ward of brooklyn. each of these schemes contemplated an extension through brooklyn to new york city at cortlandt street and broadway, and surveys and borings for this work were made across the east river. in the summer of , on the decease of mr. corbin, all projects and work were immediately stopped; but, after some months, mr. w. h. baldwin, jr., when elected president of the long island railroad company, took up actively the reconsideration of the means whereby the long island railroad could reach new york city. after the fullest consideration, he decided that the blackwell's island bridge was by no means a suitable, adequate, or convenient entry for the long island railroad into new york city, as it involved too great a cost and altogether too rigid a connection; it was also a very inconvenient location, inasmuch as it was cut off from convenient access to the west side of new york city by central park. for the down-town connection, mr. baldwin became enthusiastic, but he had in mind, throughout, the all-important necessity for the long island railroad to reach the pennsylvania railroad across the north river. at the same time mr. baldwin took up energetically the atlantic avenue improvement with the atlantic avenue commission, and, on consideration, decided it was essential that it should extend through the th ward above or below grade. the better plan, of course, was obviously to make it a subway throughout, but, further, the residents of this ward objected to the subway through that section, and that construction would have made any change of the manhattan beach division at manhattan crossing very difficult for the future; besides this, the controlling factor was the absolute limitation by the city of brooklyn of the amount of expenditure therefor in which they would participate, therefore a composite scheme, which is the plan as carried out, was agreed upon, being in part subway and part elevated. this scheme reached a focus early in , and the law constituting the board for the atlantic avenue improvement was passed, with a provision in the last paragraph of the act, for the construction of a tunnel from flatbush avenue terminal under flatbush avenue and fulton street to pineapple street, crossing the river to broadway and maiden lane (cortlandt street), new york city, and with the understanding that it would be extended beyond the new york state line to the pennsylvania railroad station in new jersey. this gave the legal right for the construction of this tunnel, and, on june th, , the new york and long island terminal railroad company was incorporated for the purpose, mr. baldwin being president and j. v. davies, m. am. soc. c. e., chief engineer. application was immediately made to the boards of aldermen of brooklyn and of new york city. the latter acted favorably on the application, but the board of aldermen of brooklyn held the matter up, while the rapid transit commission laid out and promulgated the plan for contract no. of the rapid transit subway. with the understanding that the rapid transit brooklyn extension would be constructed to the flatbush avenue terminal, mr. baldwin withdrew the application for the independent franchise, and agreed to proceed with the atlantic avenue improvement, on the basis of the city proceeding with the brooklyn extension of the rapid transit subway. this provided for the long island railroad entry down town. [illustration: plate v.--new york underground railway company section through surface and underground stations] subsequently, however, it was proved that mr. baldwin had not been fully satisfied that this was the proper solution of the matter, for on april th, , and upon his recommendation, the board of directors of the long island railroad company took over from the pennsylvania railroad company its entire interests in the old brooklyn, new york, and jersey city terminal railway company, thus giving him control of the route from flatbush avenue _via_ maiden lane and cortlandt street to underneath the jersey city station. in the early part of active consideration was being given by the pennsylvania railroad and other railroads terminating in new jersey to the proposed north river bridge, as hereinbefore stated, and, for the long island railroad, mr. baldwin organized a new company to construct a tunnel from the long island railroad at sunnyside yard, diving under the streets of long island city by two tracks under the east river to the foot of d street and then proceeding under d street as far as seventh avenue. a station was to be located at fourth avenue below the rapid transit subway station and also a large terminal station at broadway. for this purpose an option was obtained on the property of the newbold lawrence estate, at broadway, sixth avenue, d and th streets, now occupied by saks' store. mr. baldwin, however, considered that the amount of the investment ($ , , ) for that property was too great for this purpose, and allowed the option to expire. the property was sold within a week thereafter to the morganthau syndicate for $ , , . at this time (may, ), the pennsylvania railroad obtained a controlling interest in the long island railroad, and thereafter the two schemes became one. mr. baldwin and mr. rea purchased two -ft. lots on d street just east of broadway for an entrance to the underground station. plans were also prepared for extending this line from seventh avenue northward under seventh avenue to th street. the investigation and preliminary work in connection with this project were carried out in the early part of . reconsideration was given by mr. baldwin to the proposed location of the up-town tunnels, with the idea of connecting the new york central and hudson river railroad by a tunnel between long island city (long island railroad station) and the foot of d street and extending to the grand central station, but nothing further than investigation and the preparation of estimates was done on this. in the summer of mr. cassatt was in paris and was advised by mr. rea of the opening of the extension of the orleans railway to the quai d'orsay station and its successful operation by electric power, also of the possibility of the pennsylvania railroad reaching new york city in a similar way (the other trunk lines not having joined in the promotion of the north river bridge project). he at once examined the new line, and then consulted the writer in london in relation to the possibility of building tunnels under the north river. the writer returned to new york with mr. cassatt, and soon thereafter a conference of mr. cassatt, mr. rea, and mr. baldwin with the writer and mr. davies was held in the pennsylvania railroad company office in new york, when mr. cassatt outlined the scheme practically as it is now carried out, the only difference being that he also proposed a station on property of the new york and harlem railroad company at d street, which was soon abandoned on account of the grade from the east river, and particularly because of the superior location of the adopted site at seventh avenue and d street, this being central between the down-town commercial and financial district and central park, which divides new york city. on mr. cassatt's instructions, surveys and investigations were begun in november, , and estimates, drawings, etc., were made. preliminary estimates were presented to him on november th, . following this, borings were continued, and a plan was presented to mr. cassatt for assisting the support of the north river tunnels on piles, if necessary. at the time of the appointment of the board of engineers and the general organization of the work, the preliminary investigations and work had been carried to an advanced state. one result of the determination of the pennsylvania railroad company to extend its lines into new york city and thus move its principal station from jersey city, was that the down-town local and suburban as well as through business was not provided for properly. mr. william g. mcadoo, appreciating this opportunity, revived the scheme of an electric subway from jersey city to new york, originally promoted by mr. corbin and associates, but not including the extension _via_ maiden lane to brooklyn, and entered into negotiations with the pennsylvania railroad company to provide for this down-town business by extensions of the tunnel lines of the new york and new jersey railroads to exchange place, jersey city, under the pennsylvania railroad station, and thence across the hudson river to cortlandt and church streets. as a result, the hudson and manhattan railroad company was organized in , and contracts were made with the pennsylvania railroad company for the sub-surface use of its station in jersey city, and for the interchange of passenger business at that point between the trains of the pennsylvania railroad company and the tunnel of the hudson and manhattan railroad company. later, a further contract was made with the pennsylvania railroad company providing for the construction of the tunnel of the hudson and manhattan railroad company westward under the tracks of the pennsylvania railroad in jersey city to a junction with the latter at summit avenue, at which point can be installed a joint station, and the operation effected of a joint electric train service between church street, new york city, and newark, n. j., the pennsylvania railroad tracks between summit avenue and newark to be electrified for that purpose, with a transfer station established east of newark, at harrison, at which point the steam and electric locomotives will exchange. by means of this, all down-town passengers will transfer to the electric service at harrison station, and thus the pennsylvania railroad company is expected to be relieved of maintaining a separate steam service for passenger traffic to jersey city and a large down-town station with extensive contingent facilities at that point. from the foregoing it will be seen that the final decision to extend the pennsylvania railroad into and through new york city by a system of tunnels, and erect a large station in that city on a most eligible site, was not reached in a hurried or off-hand manner, but after years of painstaking study and a full and extended investigation of all routes, projects, and schemes, whether originating with the company or suggested by others. [illustration: plate vi.--pennsylvania railroad extension: map showing proposed lines leading to those finally adopted] plate vi is a map of new york city and vicinity on which are shown the various lines contemplated in the evolution of the new york tunnel extension of the pennsylvania railroad hereinbefore outlined. the question of tunnels under the north river was an uncertain factor in the larger pennsylvania railroad scheme, owing to the nature of the ground composing the river bed in which the tunnels would be constructed. it is well known that about years ago an attempt was made to construct a tunnel under the north river by using a "pilot" system under compressed air and forming the tunnels in brick masonry. owing to the very soft nature of the materials through which it passed, several serious accidents occurred, and the work was abandoned after about , ft. of tunnel had been constructed. later, this work was taken up again, when a shield was installed and an additional , ft. was built with cast-iron segmental lining, but the work was again abandoned, owing principally to financial difficulties while coincidentally before entering a rock reef which presented another serious difficulty in construction. the experience then in the construction of this tunnel led capitalists and engineers to believe that, owing to the very soft nature of the ground, a tunnel could not be built that would be sufficiently stable to withstand the vibration due to heavy traffic, and for this reason tunnels under the north river were not looked upon as practicable. the writer devised a scheme to carry within the tunnel the rolling loads on bridging supported on piers or piles extending from the tunnel invert down to hard material. these would be attached to the tunnel itself or would pass into it independently through sliding joints in the tunnel shell. this scheme gained the confidence of the management, as it was believed that, by adopting such a plan, tunnels could be built in the soft material underlying the hudson river and remain stable under all conditions of traffic. after thus feeling assured that by this method the tunnels could be made safe beyond question, orders were given to proceed with the great work of the extension into new york of the pennsylvania and long island railroad systems. [illustration: fig. .--(full page image) engineering staff organization chief engineer | chief assistant engineer | | +--(chief office) | | | +--office engineer | | | | | +--chief draftsman. | | draftsmen. | | messenger. | | | +--mechanical engineer | | | | | +--mechanical draftsmen. | | | +--assistant engineer | | | +--accountant. | clerks. | telephone operators. | messenger. | | +--(terminal station west) | | | resident engineer | | | +--assistant engineer. | | chief of party. | | instrumentmen. | | rodmen. | | chainmen. | | | +--inspectors. | | | +--clerk. | janitors. | | +--(subaqueous, nd street and weehawken tunnels) | | | general resident engineer | | | +--cement inspectors. | | ass't. cement inspectors. | | | +--photographer. | | | +--recording clerk. | | ass't. recording clerks. | | | +--dispatch boat | | | | | +--captains. | | engineers. | | deckhands. | | messenger. | | | +--resident engineers | | | +--(construction) | | | | | +--ass't. engineers. | | chief tunnel inspectors. | | tunnel inspectors. | | surface inspectors. | | clerks. | | | +--(alignment) | | | | | +--ass't. engineers. | | chiefs of parties. | | instrumentmen. | | rodmen. | | chainmen. | | rear chainmen. | | laborers. | | | +--(office staff) | | | +--draftsmen. | field office clerks. | cement warehousemen. | janitors. | messengers. | +--(medical department) | | | chief medical officer | ass't. medical officer. | | +--(bergen hill tunnels) | | | resident engineer | assistant resident engineer | | | +--assistant engineer. | | instrumentmen. | | rodmen. | | chainmen. | | | +--inspectors. | | cement warehousemen. | | | +--clerk. | janitors. | | +--(metal inspection) | chief metal inspector metal inspectors. clerks. ] the organization of the engineering staff is shown on the diagram, fig. . in the beginning of and during the period of making studies, additional borings, and preliminary triangulations, and prior to making the contract plans and specifications, james forgie, m. am. soc. c. e., was appointed chief assistant engineer by the writer. to him all the resident engineers and other heads of the engineering departments reported. the work was divided into three residencies: .--the terminal station-west, under the charge of b. f. cresson, jr., m. am. soc. c. e., resident engineer, comprising the work from the east side of ninth avenue to the east side of tenth avenue, including excavation, retaining and face walls, and the extensive work of underpinning ninth avenue with its surface and elevated railroads and other structures. .--the river tunnels, under the charge of b. h. m. hewett, m. am. soc. c. e., general resident engineer, and mr. h. f. d. burke and william lowe brown, m. am. soc. c. e., resident engineers, including the land tunnels from the east side of tenth avenue, new york city, to the commencement of the iron-lined tunnels, and extending westward from there to the weehawken shaft, new jersey. .--the bergen hill tunnels, under the charge of f. lavis, m. am. soc. c. e., resident engineer, including the rock tunnels from the weehawken shaft to the hackensack portal on the west side of the palisades, all in new jersey. paul a. seurot, m. am. soc. c. e., acted as office engineer in charge of the drawing office, and mr. j. soderberg as mechanical engineer in charge of the mechanical drafting. prior to the construction of the above works mr. c. j. crowley acted as resident engineer on the construction of the weehawken shaft, and j. f. rodenbough, assoc. m. am. soc. c. e., on that of the manhattan shaft. table shows the quantities of certain materials and other statistics regarding this division. table . ------------------------------------------+---------+-----------+---------- | bergen | river | term. | hill. | tunnels. | sta.-w. +---------+-----------+---------- | | | excavation disposed of (or displaced), | | | in cubic yards | , | , | , cast metal used in tunnel, including | | | cast iron and cast steel, in tons | | , | steel bolts used, in tons | | , | cement used (concrete and grout), | | | in barrels | , | , | , concrete, in cubic yards | , | , | , dynamite for blasting, in pounds | , | , | , brickwork, in cubic yards | | , | structural steel (including pier ), | | | in pounds | , | , , | , , ------------------------------------------+---------+-----------+---------- the number of passengers carried on the elevated railroad and surface lines of ninth avenue during the underpinning of these structures was about , , . the board of engineers, organized by the pennsylvania railroad company in january, , immediately took up the matter of route and grade. the center line, which had been assumed as the center line of d street extended westward, was slightly changed. the grade adopted was approximately % descending westward from ninth avenue, which would place the tunnel well below the government dredging plane of ft. below mean low water at the pier head line; thence westward on a lighter grade still descending until the deepest portion of the river was reached where the top of the rail would be about ft. below mean high water, this location giving sufficient cover over the tunnels to insure stability and guard against the possibility of shipwrecks settling on the tunnels. from this point to the portal an ascending grade of . % was adopted, which gave the lines sufficient elevation to cross over the tracks of the new york, susquehanna and western and the erie railroads, which run along the westerly base of the palisades. owing to the exigencies of construction, these grades in the river were very slightly modified. plate vii is a plan and profile of the tunnels as constructed. [illustration: plate vii.--plan, profile, and triangulation, north river tunnels] the board of engineers early in took up the question of supports for the tunnels under the north river, and various plans and schemes were considered. it was finally decided to support the tracks on screw-piles carried through the lining of the tunnels, as originally proposed by the writer. in order to know something of the capacity of screw-piles in the actual material to be passed through, it was resolved to test them. a caisson was sunk at the end of one of the erie railroad piers on the new jersey side near the line of the tunnels, and, to obtain parallel conditions as much as possible, the excavation was carried down to the proposed grade of the tunnel. various types of screw-piles were sunk therein and tests were made, not only of the dead load carrying capacity, but also with the addition of impact, when it was found that screw-piles could be sunk to hard ground and carry the required load. the final part of the test was the loading. the screw-pile, having a shaft in. in diameter and a blade ft. in diameter, was loaded with , lb., with the result that, for a month--the duration of this loaded test--there was no subsidence. again, and after the iron tunnel lining had been constructed across the river, tests were made of two types of supports: one a screw-pile - / in. in diameter with a blade ft. in. in diameter and the other a wrought-iron pipe in. in external diameter. tests were made, not only for their carrying capacity, but also for their value as anchorages, and it was found that the screw-pile was more satisfactory in every way; it could be put down much more rapidly, it was more easily maintained in a vertical position, and it could carry satisfactorily any load which could be placed on it as a support for the track. the -in. pipe did not prove efficient either as a carrier or as an anchorage. these tests will be mentioned in the detailed description of the work to follow. figs. and illustrate the general arrangement and details of the machine designed by the writer and used for sinking the test piles in the tunnels. this machine had been used originally on the new jersey side on the test pile at pier c, and the adaption was not exactly as shown on these drawings, but if the screw-piles had been placed in the tunnels, the arrangement shown would have been used. surveys, soundings, and borings were commenced in the latter part of on an assumed center line of tunnels which was the center line of d street extended westward. the soundings were made from a float stage fastened to a tugboat, the location being determined by transits on shore and the elevation by measuring from the surface of the water, a tide gauge being continually observed and the time of soundings and gauge readings kept. in the river wash-borings were made from a floating pile-driver on which was installed a diamond-drill outfit of rods, pump, etc. fourteen borings were completed in the river. considerable difficulty was found in holding the pile-driver against the current, the material in the bottom being very soft, and several borings were lost owing to the drifting of the pile-driver. each boring was continued, and the depth of several was more than ft. below the surface of the water. the borings on land were mostly core borings, and were generally made with the chilled shot boring machine. base lines, about , ft. in length, were measured on each side of the river, and observation points established. it was necessary to build a triangulation tower ft. high on the new jersey side as an observation point. the base lines were measured with -ft. steel tapes which were tested repeatedly, and the work was done at night in order to obtain the benefit of uniform temperature and freedom from traffic interruptions. from the base line on the new jersey side, which passed over the weehawken shaft, an elevated point on the assumed center line on the side of bergen hill was triangulated to, and from this point westward a closed polygon was measured along the streets to the top of the hill on the west side and thence along the assumed center line to the portal. the level transfer across the river was made by sighting across in opposite directions simultaneously, and also by tide gauges. the outline of the final triangulation system is shown on plate vii. [illustration: fig. .--(full page image) hydraulic screwing machine with ratchet drive and vertical jack general arrangement] [illustration: fig. .--(full page image) hydraulic screwing machine with ratchet drive and vertical jack details] the decision as to the locations of the shafts on both sides of the river, for construction purposes and finally for permanent use, was a comparatively simple matter, and, all circumstances considered, they are unquestionably in the most suitable places. on the new york side the shaft was as near as practicable to the line dividing the subaqueous iron-lined tunnels from the land tunnels, and on the new jersey side the shaft was placed centrally on the line of the tunnels and on the nearest available ground to the river, while at the same time beyond the other end of the river tunnels, thus necessitating driving the subaqueous tunnels only from east and west to meet under the river. a caisson shaft on the new york side, on the line of the tunnels near the river bulkhead, was at one time considered, but was not adopted as it entailed the driving of two shields both east and west, in addition to the two from new jersey, adding to the plant outlay while not affording any material saving in the time of construction. it was thought desirable to construct the shafts on the two sides of the river in advance of letting the main contracts for the tunnels. the manhattan shaft is north of the line of the tunnels, on the north side of d street, east of eleventh avenue. the weehawken shaft is on the line of the tunnels in the yards of the erie railroad on the new jersey side, and the distance between the shafts is about , ft. the contracts for these shafts were let in june, , to the united engineering and contracting company, and they were completed and ready for use at the time of letting the main contract for the tunnels, thus saving considerable time. _the terminal station-west.--between ninth and tenth avenues._--in the original design it was contemplated to have a four-track tunnel under d street from ninth to eleventh avenues, but owing to the necessity for having additional yard facilities, property was bought for about ft. north and ft. south of d street, between ninth and tenth avenues, and an open excavation, lined with concrete retaining walls and face walls, was made. between ninth and tenth avenues, d street was closed, and the property formerly the street was bought by the tunnel company from the city of new york for a consideration by deed dated april th, . the church, rectory, and school of st. michael's, which was located on the west side of ninth avenue between st and d streets, was acquired by the tunnel company after it had acquired property for and had built a similar institution on the south side of th street west of ninth avenue. probably the most interesting feature of this contract was the support and maintenance of ninth avenue, which has a three-track elevated railway structure and a two-track surface railway structure, on which it was necessary to maintain traffic while excavation was made to a depth of about ft., and a viaduct was erected to carry ninth avenue. the length of this viaduct is about ft., and the steelwork and its erection was done apart from the north river division work, but all excavation and underpinning was included in this division. the contract for this work on the terminal station-west was let to the new york contracting company-pennsylvania terminal, on april th, , and included about , cu. yd. of excavation, about % being rock, the construction of about , lin. ft. of retaining and face walls containing about , cu. yd. of concrete, and a large quantity of structural steel ( , , lb.) for temporary use in underpinning ninth avenue. fig. shows cross-sections of the terminal station-west yard, and fig. shows the general method of underpinning the ninth avenue structures. [illustration: fig. .--terminal station west typical sections] _river tunnels._--in the original plan a four-track tunnel was contemplated from the east side of tenth avenue to the east side of eleventh avenue, but, owing to the extension of the terminal yard, previously noted, this plan was changed, and a two-track structure was built having a central wall between the tracks. this was constructed in tunnel, with the exception of ft. about midway between tenth and eleventh avenues, where the rock dipped below the roof of the tunnel, and there the construction was made in open cut. these tunnels were lined with concrete with brick arches, figs. , , and being typical cross-sections. this work was executed by the o'rourke engineering construction company, under a contract dated november st, . it was possible to excavate in full rock cover about ft. of the tunnels eastward from the weehawken shaft and ft. westward from the manhattan shaft. at these points the rock cover was very thin, and there shield chambers were made for the erection of two sets of shields, about , ft. apart. a typical cross-section of the weehawken land tunnel is shown on plate viii. [illustration: plate viii.--typical sections between manholes, bergen hill tunnels] the board of engineers decided, and it was so stated in the contract and specifications, that the river tunnels should be constructed by means of hydraulic shields, but bidders were permitted to present to the board any scheme on which they might desire to bid, but, of course, the decision as to the practicability of such plans rested with the board. inasmuch as the shield method of construction was required, the writer designed a shield for use in the north river tunnels. the shield was about ft. long, over all, and was provided with a rigid but removable hood extending beyond the normal line of the cutting edge, for use in sand, gravel, and ballast, to be removed when the shield reached the silt. the shields were thrust forward by twenty-four rams capable of exerting a pressure of , tons at a hydraulic pressure of , lb. per sq. in. taking into account lb. air pressure, this pressure was increased to , tons. the shield was fitted with a single hydraulic erector and hydraulic sliding platforms, and when complete weighed tons. fig. is a back elevation and section of the shield. the contract for the river tunnels was let to the o'rourke engineering construction company on may d, . the shields were built in accordance with the design previously referred to, and proved entirely satisfactory. generally, the materials passed through were as follows: starting out in full face rock, from it into a mixed face of rock and sand, thence into sand and gravel, full face of sand, piles, rip-rap, and the hudson silt; and all were fully charged with water. compressed air, at an average gauge pressure of about lb. and a maximum of lb. per sq. in., was used in the tunnels from the time the shields emerged from full rock face until the tunnel lining had been joined up and all caulking and grummeting had been done. [illustration: fig. .--(full page image) arrangement of structures supporting ninth ave. during progress of excavation] contractor's plants were established at the weehawken shaft and at the manhattan shaft, including at each, low-pressure air compressors of a capacity of , cu. ft. of free air per minute and also high-pressure air compressors for drills, hydraulic pumps, electric generators, etc. the river tunnels passed under pier , north river (old no. ), which was occupied by the new york central and hudson river railroad company. the tunnel company leased this pier and withdrew all the piles on the lines of the tunnels prior to the commencement of construction, and on the remaining piles constructed a trestle for the disposal of the excavation from the tunnels and the terminal. at the completion of the work this pier had to be restored, and fig. shows the general arrangements of the location of the piles and the pier structure with reference to the tunnels. in the tunnels which were constructed in silt farther down the river, by the writer as chief engineer for the hudson companies, it had been possible to shove the shield through the silt with all the doors closed, displacing the ground and making great speed in construction owing to the absence of all mucking. it was thought that this procedure might be pursued in the larger tunnels of the pennsylvania railroad, and it was tried, but it was almost immediately found to be impossible to maintain the required grade without taking a certain quantity of muck into the tunnels through the lower doors, the tendency of the shield being to rise. by taking in about % of the excavation displaced by the tunnel, the grade could be maintained. it was considered desirable, owing to this rising of the shields, to increase the weight of the cast-iron lining, and this was done, making the weight of the completed tunnel more nearly equal to the weight of the displaced material. the weight of the cast-iron lining (with bolts) was increased from , to , lb. per lin. ft. of tunnel. the weight of the finished tunnel with this heavier iron is , lb. per lin. ft. the weight of the silt displaced per linear foot of tunnel, at lb. per cu. ft., is , lb. the weight of the completed tunnel with the maximum train load is , lb. per lin. ft. the maximum progress at one face in any one month was ft., working three -hour shifts, and the average progress in each heading while working three shifts was ft. per hours; while working one shift with the heavier lining referred to above, the delivery of which was slow, the average progress was ft. per hours. [illustration: fig. .-- ' " span twin tunnels. rock roof.] [illustration: fig. .-- ' " span twin tunnels.] [illustration: fig. .-- ' " span twin tunnels] [illustration: fig. .--proposed shield for subaqueous tunneling general elevation] [illustration: fig. .--restoration of pier (old ) north river transverse section at center of pier] in order to permit the screw-piles to be put in place through the lining, cast-steel bore segments were designed, and placed in the invert at -ft. centers; these are of such a design as to permit the blade and shaft of the screw-pile to be inserted without removing any portion of the lining. fig. is a typical cross-section of the river tunnel, as originally planned, with these pile supports. after the shields had met and the iron lining was joined up, various experiments and tests were made in the tunnel; screw-piles, and -in. pipes, previously referred to, were inserted through the bore segments in the bottom of the tunnel, thorough tests with these were made, levels were observed in the tunnels during the construction and placing of the concrete lining, an examination was conducted of the tunnels of the hudson and manhattan railroad company under traffic, and the result of these examinations was the decision not to install the screw-piles. the tunnels, however, were reinforced longitudinally by twisted steel rods in the invert and roof, and by transverse rods where there was a superincumbent load on the tunnels; it might also be noted that on the new york side, where the tunnels emerge from the rock and pass into the soft material, the metal shell is of cast steel instead of cast iron. fig. is a typical cross-section of the river tunnels as actually constructed. [illustration: fig. .--(full page image) cross-section of tunnel showing track system and screw-pile.] [illustration: fig. .--subaqueous tunnels cross-sections] during the investigations in the tunnels, borings were made to determine exactly the character of the underlying material, and it was then found that the hard material noted in the preliminary wash-borings was a layer of gravel and boulders overlying the rock. when the borings in the tunnels reached this material it was found to be water-bearing and the head was about equivalent to that of the river. rock cores were taken from these borings, and the deepest rock was found at about the center of the river at an elevation of . ft. below mean high water. rods were then inserted in each bore hole and thereby attached to the rock and used as bench-marks in the tunnels. from these bench-marks, using specially designed instruments, very accurate observations of the behavior of the tunnels could be made, and from these the very interesting phenomenon of the rise and fall of the tunnels with the tide was verified, the tunnels being low at high tide and the average variations being about . ft. in the average tide of about . ft.: the tidal oscillations are entirely independent of the weight of the tunnels, since observations show them to have been the same both before and after the concrete lining was in position. there was considerable subsidence in the tunnels during construction and lining, amounting to an average of . ft. between the bulkhead lines. this settlement has been constantly decreasing since construction, and appears to have been due almost entirely to the disturbances of the surrounding materials during construction. the silt weighs about lb. per cu. ft. (this is the average of a number of samples taken through the shield door, and varied from to lb. per cu. ft.), and contains about % of water. it was found that whenever this material was disturbed outside the tunnels a displacement of the tunnels followed. the tunnels as above noted have been lined with concrete reinforced with steel rods, and prior to the placing of the concrete the joints were caulked, the bolts grummeted, and the tunnels rendered practically water-tight; the present quantity of water to be disposed of does not exceed gal. per hours in each tunnel , ft. long. _bergen hill tunnels._--these are two single-track tunnels, ft. from center to center, and extend for a distance of , ft. from the weehawken shaft to the hackensack portal. they were built almost entirely through trap rock. the contract was let on march th, , to the john shields construction company, but was re-let on january st, , to william bradley, the shields company having gone into the hands of a receiver. about , ft. of the tunnel excavation was done by the shields company, but no concrete lining. the maximum monthly progress for all headings was ft., and the average progress was ft. a working shaft ft. deep was sunk from the top of the hill, to facilitate construction. the tunnels are lined with concrete throughout. typical cross-sections of these tunnels are shown on plate viii. in conclusion it may be admissible for the writer after having, in conjunction with mr. samuel rea, experienced the evolution and materialization of this pennsylvania railroad scheme, to express his great sorrow for the untimely death of the father of the entire scheme, the late president cassatt. american society of civil engineers instituted transactions paper no. the new york tunnel extension of the pennsylvania railroad. the cross-town tunnels.[a] by james h. brace and francis mason, members, am. soc. c. e. in this paper, it is proposed to describe the construction of the tunnels extending eastward from the easterly extension of the terminal station to the permanent shafts east of first avenue. they were located under d and d streets from the station to second avenue, and thence, curving to the left, passed under private property and first avenue to the shafts, as described in a preceding paper. typical cross-sections of the tunnels are shown on plate xii.[b] on may th, , a contract was entered into with the united engineering and contracting company for the performance of this work. this contract provided that work on each pair of tunnels should be carried on from two shafts. the first, here referred to as the first avenue shafts, were located just east of that avenue and directly over the line of the tunnels; the other two, called the intermediate shafts, were located on private property to the north of each pair of tunnels in the blocks between fourth and madison avenues. it was originally intended to do all the work of construction from these four shafts. workings were started both east and west from the intermediate shafts, and those to the west were to be continued to the terminal station. after the change of plans, described in a previous paper, it was decided to sink a third shaft on each line. these were known as the west shafts, and were located between sixth and seventh avenues. finally, it was found necessary to build a portion of the tunnels on each line west of sixth avenue in open cut. the locations of the shafts are shown on plate xiv.[c] the first avenue shafts were built by s. pearson and son, inc., for the joint use of the two contractors, as described in the paper on the tunnels under the east river. while the shafts were being sunk, the full-sized tunnels were excavated westward by the contractor for the river tunnels for a distance of ft., and top headings for ft. farther. by this means, injury to the caissons and to the contractor's plant in the shafts by the subsequent work in the cross-town tunnels was avoided. the west half of the shaft was for the exclusive use of the contractor for the cross-town tunnels. contractor's plant. the method of handling the work adopted by the contractor was, broadly speaking, as follows: excavation was usually carried on by modifications of the top-heading and bench method, the bench being carried as close to the face as possible in order to allow the muck from the heading to be blasted over the bench into the full section. the spoil was loaded into -yd. buckets (designed by the contractor and hereinafter described), by steam shovels operated by compressed air, and hauled to the shafts by electric locomotives. electrically-operated telphers, suspended from a timber trestle, hoisted the buckets, and, traveling on a mono-rail track, deposited them on wagons for transportation to the dock. arriving at the dock, the buckets were lifted by electrically-operated stiff-leg derricks and their contents deposited on scows for final disposal. the spoil was thus transported from the heading to the scow without breaking bulk. when concreting was in progress, the spoil buckets were returned to the shafts loaded with sand and stone. the concrete materials were deposited in storage bins placed in the shafts, from which they were fed to the mixers located at the foot of the shaft about on a level with the crown of the tunnels. the concrete was transported to the forms in side-dump, steel, concrete cars, hauled by the electric locomotives. electrical power was adopted largely on account of the restricted area at the shaft sites, where a steam plant would have occupied considerable space of great value for other purposes. the installation of a steam plant at the intermediate shafts, which were located in a high-class residential district, would have been highly objectionable to the neighboring property owners, on account of the attendant noise, smoke, and dirt, and, in addition, the cost of the transportation of fuel would have been a serious burden. except for the forges and, toward the last, the steam locomotives, not a pound of coal was burned on the work. the use of the bucket and telpher also eliminated most of the objectionable noise incident to the transfer of spoil from tunnel cars to ordinary wagons at the shaft sites. power plants were installed at the north shaft near first avenue and at the rear of the d street intermediate shaft. _first avenue plant._--fig. , plate lviii, is a general view of the first avenue plant. the power-house at the corner of th street and first avenue supplied compressed air for operating drills, shovels, pumps, and hoists in the tunnels driven from the river shafts, and in it three laidlaw-dunn-gordon compressors were installed. the largest was a by by -in., two-stage, cross-compound, direct-connected to a fort wayne h.p., -volt, direct-current, constant-speed motor run at rev. per min. this compressor was rated at , cu. ft. of free air per minute at a pressure of lb. it was governed by throttling the suction, the governor being controlled by the pressure in the air receiver and the motor running continuously at a constant speed. the two others were of similar type, one was - / by by -in., rated at , cu. ft. of free air at a pressure of lb., the other was by by -in., rated at cu. ft. they were fitted with -ft. fly-wheels, and were driven at rev. per min. by -h.p., general electric, -volt, compound-wound, direct-current motors running at rev. per min. the larger of these two compressors was driven by two of the motors belted in tandem, and the smaller was belt-connected to a third motor. the compressors were water-jacketed and had small inter-coolers, the water supply for which was itself cooled in a wheeler condenser and engineering company's water-cooling tower. the pump and the blower operating it were electrically driven. the telphers, used for hoisting muck from the tunnels and for lowering supplies, were each hung from single rails on a timber trestle, about ft. high, spanning and connecting the two shafts. one machine was provided for each shaft, and where their tracks crossed d street they were separated sufficiently to permit the machines to pass each other. at this point, and covering the street, a large platform was provided, on which the trucks were loaded and unloaded (fig. , plate lviii), and from which they descended by an incline on first avenue leading south to d street. the platform also covered practically all the yard at the south shaft and materially increased the available working area. the telphers were built by the dodge cold storage company, and were operated by a -h.p. general electric motor for hoisting and a -h.p. northern electric company motor for propulsion. their rated lifting capacity was , lb. at a speed of ft. per min. the carpenter shop and machine-shop, both of which served the entire work, were conveniently located in small buildings on the loading platform. in the former the saws were each run independently by small electric motors suspended under the platform. the heavy forms and form carriages used in lining the tunnels with concrete were fabricated and stored on the platform outside. the machine-shop lathes, etc., were all belted to one shaft driven by an -h.p. general electric motor. above the machine-shop was a locker-room and below it on the street level was the main blacksmith shop for the work. subsidiary blacksmith shops were located at each of the other shafts. the storeroom and additional locker-rooms were located above the power-plant in the north shaft yard, and isolated from the other structures was a small oil-house. additional storage space was provided by the contractor on d street just west of first avenue by renting three old buildings and the yards in the rear of them and of the railroad company's cement warehouse adjacent. here electric conduits, pipe, castings, and other heavy and bulky supplies were stored. during excavation the headings were supplied with forced ventilation through -in. and -in. no. , spiral-riveted, asphalted pressure pipes, canvas extensions being used beyond the ends of the pipes. a no. american blower, located at the top of each shaft and driven by a -h.p. general electric motor, supplied the air. [illustration: plate lviii, fig. .--view of first avenue plant.] [illustration: plate lviii, fig. .--telpher structure and loading platform, first avenue shaft.] [illustration: plate lviii, fig. .--headworks at d street: intermediate shaft.] [illustration: plate lviii, fig. .--loading spoil on barges, th street pier.] a concrete-mixing plant was placed in each shaft, the mixer being located high enough to discharge into cars at about the level of the springing line of the arch. above the mixers were the measuring hoppers set in the floor of a platform which was large enough to carry half a day's supply of cement. at the south shaft the cement was delivered to this floor from the loading platform through a spiral steel chute; at the north shaft it was lowered in buckets by the telpher. the sand and stone were drawn into the hoppers through short chutes from the base of the storage bins which occupied the remaining height of the shaft--about ft. at the south shaft the bins were of concrete and steel, about by ft. in section, and attached to the central wall of the caisson. sand and stone were delivered into them from dump-wagons on the loading platform. at the north shaft steel-plate bins were used, and were supplied with material by the buckets handled by the telpher. the mixers were no. smith, belt-connected to -h.p. motors, and about . cu. yd. of concrete was mixed at a batch. the concrete cars were steel side-dumpers of the wiener or koppel type. in order to be able to continue concreting during the winter, when neither sand nor stone could be obtained by water, practically all the space under the loading platforms in the south shaft yards not occupied by the blacksmith shop was filled with these materials, which were placed in storage in the late fall. _intermediate-shaft plant._--the air-compressing plant was located at the rear of the d street intermediate shaft, and supplied air for driving the tunnels east and west from the intermediate shafts on both d and d streets. two compressors, the same as the large laidlaw-dunn-gordon machine at first avenue, were installed here, with a similar water-cooling tower. both shafts were on private property, owned by the railroad company, on the north side of the streets, and each was equipped with two telphers supported on timber trestles, similar to those at first avenue. here, however, the buckets were placed on wagons standing at the curb, as shown by fig. , plate lviii. blowers for ventilation were installed at each shaft, as at first avenue, and, after the excavation had proceeded some distance, small blacksmith shops, for sharpening drill steel and making minor repairs, were located in the tunnels near the shafts. the concrete plant in each shaft was similar in arrangement to those at first avenue, but the storage bins had wooden walls made of by -in. and by -in. scantling nailed flat on each other. the contractor's office on d street backed up against the d street shaft site, and the basement was used as a storeroom for supplies for both shafts. after the decision to do part of the work between sixth and seventh avenues in open cut, an -in. air main was laid in d street to the west shafts, and air was supplied from the intermediate shaft for work on both streets in that neighborhood. _west-shaft plant._--west of sixth avenue, between d and d streets and adjacent to the open-cut sections, the railroad company obtained from the hudson and manhattan railroad company the use of a large area from which the buildings had recently been removed, and gave the use of it to the contractor. this was of great value in prosecuting the west end of the work. the two west shafts were located in the streets and were supplied with short timber trestles similar to those at the intermediate shafts. one telpher was taken from each of the intermediate shafts to operate at each of the west shafts. in addition, a number of stiff-leg derricks were set up along the open-cut section, and were operated by lidgerwood or lambert air hoisting engines, or by electric motors, as circumstances dictated. a -ton bay city locomotive crane was also used along part of the open-cut work on d street. several concrete plants were installed at points along the open-cut section, and were moved from place to place, the same general arrangement being adopted as at the plants already described. no. and no. ransome mixers were used, and were generally set up at about the level of the top of the arch. the sand and stone storage bins were made of scantlings spiked together, and were necessarily rather shallow on account of the proximity of the tunnels to the street surface. _thirty-fifth street pier._--for the receipt and disposal of materials at the th street pier, four stiff-leg derricks, operated by electric hoisting engines, were installed. two were used in lifting the muck buckets from the wagons and dumping their contents on the scows for final disposal (fig. , plate lviii); and the other two were fitted with clam-shell buckets for unloading sand and broken stone from barges and depositing the materials in large hoppers, from which they were drawn into wagons for transportation to the various concrete plants. a large part of the cement (all of which was supplied by the railroad company) was also unloaded at the th street pier and hauled directly to the work, the surplus being stored temporarily in the company's cement warehouses on d, d and th streets, near first avenue, from which it was drawn as required. on the dock was located the main powder magazine, a small concrete structure. considerable use was also made of neighboring piers for unloading electric conduits, lumber, steel, etc. [illustration: fig. . special steel bucket plan of bucket end view side view of bucket section at a-a] _tunnel plant._--the spoil buckets, designed by d. l. hough and george perrine, members, am. soc. c. e., were a novel feature of the work. these buckets are shown in detail in fig. and various photographs. they were of cu. yd. capacity and were split longitudinally, the two halves being pinned at the apices of the ends. for lifting, they were suspended from eyes at that point, and, when dumping, trip ropes were hooked into eyes at the bottom of each side; lifting the trip ropes or lowering the hoisting rope split the bucket, as shown in fig. , plate lviii, and dumped the contents. they were transported in the tunnel on flat cars, and in the street on wagons, both cars and wagons being provided with cradles shaped to receive the bottom of the bucket. in the tunnels the loading was done with air-operated steam shovels, four (model ) marion shovels being used at various points of the work. in fig. , plate lix, one of these is shown loading the bucket. the cars were hauled by general electric, standard, -ton, mine locomotives, the current for which was taken at volts from a pair of no. copper trolley wires suspended from the roof of the tunnel. the collector was a small four-wheeled buggy riding on the wires and connected to the locomotive by several hundred feet of cable wound on a reel for use beyond the end of the trolley wire. two - / -ton, davenport, steam locomotives were also used in d street, toward the end of the work, after the headings had been holed through and the tunnels would quickly clear themselves of gas and smoke. the steam shovels were supplemented by two browning, -ton, locomotive cranes, which handled the spoil in places where timbering interfered with the operation of the shovels. all tracks were of -ft. gauge throughout and laid with -lb. rails. practically all the heavy drilling was done with ingersoll drills (model e ), the trimming being largely done with jap and baby drills. a large number of pumps were used at various points on the work, and practically all were of cameron make, the largest ones at the shaft being by by -in. the grout machines were of the vertical-cylinder, air-stirring type. shaft sinking. the sinking of the intermediate shafts was the first work undertaken by the contractor. the d street shaft was . ft. long, ft. wide, and ft. deep. the rock surface averaged ft. below the ground surface. sinking was started on july th, , and was completed on october d, , the rock being hard and dry. the average daily rate was . ft. and an average of . cu. yd. were excavated per day, with two shifts of hr. each. the first shift started at a. m. and the second at . p. m., ending at p. m. these hours were adopted in order to avoid undue disturbance during the night. [illustration: plate lix, fig. .--air-operated steam shovel used in tunnel.] [illustration: plate lix, fig. .--timbering in top headings above i-beams.] [illustration: plate lix, fig. .--first section of concrete lining at fifth avenue.] [illustration: plate lix, fig. .--timbering and rubble masonry over i-beams.] before blasting the first lift of rock, channel cuts or ft. deep were made along the sides of the shaft, in order to avoid damage to the walls of neighboring buildings. timbering was required for a depth of only ft. below the surface of the ground. a drift, . ft. long, ft. wide, and ft. high, connected the south end of the shaft with the tunnels. the drift was excavated in three stages, a top heading and a bench in two lifts. while blasting the cut in the top heading, there was enough concussion to break glass in the neighboring buildings. the use of a radialax machine reduced the concussion somewhat, but it was very quickly abandoned on account of the length of time required for the drilling. the construction of the d street shaft was quite similar to the one on d street. it was . ft. long, . ft. wide, and ft. deep. the depth of earth excavation averaged . ft. the rock in this shaft was seamy and not quite as hard or dry as that in d street, and timbering was required for practically the full depth to the crown of the drift. sinking was started on may th, , and was completed on october th, . the daily average rate was . ft. in earth and . ft. in rock. the drift was excavated in much the same manner as the one in d street, but the rock being softer the radialax machine was not used. tunnel excavation. during the early part of the work, the contractor devoted his entire attention to the work of excavation. nearly all the excavation east of fifth avenue was done before any of the lining was placed. at a number of points west of fifth avenue and at a few points to the east the nature of the rock was such that the two operations had to be done simultaneously. _single-tunnel method._--for an average distance of ft. west from the first avenue shafts there were four single tunnels. the rock was sound and comparatively dry. a top heading of the full size of the tunnel and about ft. high was first driven. it was drilled by four drills mounted on two columns, and was blasted in the ordinary way. the bench was about ft. high. tripod drills, standing on the bench, drilled the usual holes, but, owing to the lack of head-room, steels long enough to reach the bottom of the bench could not be used. tripod drills were set as low as possible at the foot of the bench and drilled lifting holes. these holes were inclined downward from ° to ° to the horizontal, and were spaced to converge at the location of the drainage ditches. the heading was usually driven from to ft. in advance of the bench. at this distance a large part of the muck from the heading was shot backward over the bench. in the single tunnels the muck was loaded by hand. _twin-tunnel methods._--from the end of the single-track tunnel westward to fifth avenue on d street, and to madison avenue on d street, with some exceptions, each pair of tunnels was excavated for the entire width at one operation. three different methods of work were extensively used. they were the double-heading method, the center-heading method, and the full-sized-heading method, and these differed only in the manner of drilling and blasting. the bench was usually within or ft. of the face of the heading, and was drilled and fired in the same way as in the single tunnels. after the installation of the permanent plant, most of the muck was handled by steam shovels. in the double-heading method, shown on plate lvii, the top headings for each tunnel of the pair were driven separately, leaving a short rock core-wall between them. the headings were drilled from columns in the manner described for the single tunnels. the temporary rock dividing wall between the headings was drilled by a tripod drill on the bench of one of the headings, and was fired with the bench. in the center-heading method, also shown on plate lvii, only one heading was driven. it was rectangular in shape, about ft. high and ft. wide. it was located on the center line between the tunnels. in general, the face was from to ft., or the length of one or two rounds, in advance of the remainder of the face at the top. the center heading was drilled by four drills mounted on two columns. by turning these drills to the side, they were used for holes at right angles to the line of the tunnels, by which the remainder of the face of the heading was blasted. by turning the drills downward, the bench holes under the center heading were also drilled. the center heading explored the rock in advance of the full-width heading, and gave a good idea as to the care needed in firing. for the full-width-heading method, fig. , ten drills were mounted on five columns set abreast across the face. holes were drilled to form a cut near the center line between the tunnels. the remainder of the holes were located so that they would draw into the cut. the bench was frequently drilled from the same set-up of columns by turning the drills downward. in sound rock this method proved to be the most rapid of any. practically all trimming was left until immediately before the concreting. it was then taken up as a separate operation, but proved to be costly and tedious, and a hindrance to the placing of the lining. _materials encountered._--all the rock encountered was the familiar hudson schist, but it varied widely in its mineral constituents and in its physical characteristics. in many places where the rock surface was penetrated, a fine sand was found that was probably quicksand. the material above the rock in the open-cut sections was mostly sand. [illustration: fig. . method of excavating with full-width heading cross-town tunnels, manhattan side elevation front elevation plan showing position of columns for drilling face] the concurrence of the watercourse, shown on general viele's map of manhattan island (plate ix[d]), with the points where difficulties in the construction of the tunnels were encountered has been noted in a previous paper. in all cases where the course of this ancient stream was crossed (except at its final intersection of d street), the rock was found to be very soft and disintegrated, a large quantity of water was encountered, and heavy timbering was required. the construction at these localities will be taken up later. in addition, disintegrated rock, but of a less troublesome character, was invariably met under the depressions in the rock surface developed by the borings from the streets and test holes from the tunnels. many of these places required timbering, and no timbering was elsewhere necessary except at the portals. these coincident conditions were especially marked in d street, which for a long distance closely adjoins the course of the former creek. _disposal of spoil._--the materials excavated from the tunnels were dumped at the th street pier on barges furnished by the railroad company under another contract, and were towed to points near the bayonne peninsula where the spoil was used principally in the construction of the greenville freight yards and the line across the hackensack meadows to the tunnels. details of this work will be given in a subsequent paper. after december, , when the excavation was about % completed, the contractor furnished the barges and effected the complete disposal of the spoil. _difficulties of excavation._--as stated in a previous paper, the excavation of the twin tunnel in d street was continued westward to the west line of fifth avenue on the original grade. at that point the contractor started three drifts in the three-track section. the relation of the drifts to each other and to the cross-section are shown by fig. . the center heading was driven a little in advance of those on the sides. at a distance of ft. west of fifth avenue the rock surface was broken through in the top of the heading, and a very fine sand was encountered. for some distance east of this point the rock was badly disintegrated, and the heading required timbering. through the soft material, tight lagging was placed on the sides and roof of the heading, and the face was protected by breast boards. there was a moderate flow of water through the cracks, and, in spite of every effort, some of the fine sand was constantly carried into the heading. in one or two instances considerable ground was lost at the face. on the evening of december th, , as a heavy coal wagon was passing along d street above the heading, the rear wheels dropped through the asphalt pavement. an examination disclosed a cavity under the pavement about ft. long, ft. wide and ft. deep. evidently, the fine sand had gradually settled into the voids caused by the loss of material at the face, and the settlement broke the brick sewer over the heading. the sewer was temporarily repaired, and the hole in the street was filled before morning. a tight bulkhead was built across the heading, and work was abandoned at that point. the north drift was advanced to a point ft. west of fifth avenue where sand was also encountered and a considerable run occurred. after that time all work on the three-track section was discontinued. the company then took up the consideration of changes in plan. to determine the difficulties of driving a twin tunnel at a lower elevation, an exploration drift, ft. high and ft. wide, was driven on the center line of the street as a top heading on the proposed new grade. test holes were drilled above this heading and to the sides. the results indicated that there was sufficient rock cover of fair quality to enable the twin tunnel to be driven without great risk. the new plan (continuing the twin tunnel westward at a lower grade) was adopted in march, , and work was immediately resumed at fifth avenue. the relation between the cross-sections under the old and new plans at that point is shown by fig. . before the new section was excavated it was necessary to support the timber work in the old headings. the plan adopted is also shown by fig. . the rock was excavated under the center heading, as shown in cross-section, for a length of about ft. a girder composed of two -in. i-beams was then put in position over each line and supported on the sides by posts. the ends at the center lines between the tunnels were supported on short posts bearing on the rock bench. the support of the timbering in the headings was then transferred to the girders by additional posts. blocking was also inserted between the tops of the beams and the rock walls between the headings. fig. , plate lix, gives a good idea of the timber work in the top headings above the i-beams. when the roof had been made secure, the removal of the bench was begun. as the work advanced it was necessary to replace the short posts at the center of the tunnel by others of full height, and there was considerable settlement in the i-beams during this operation. when the bench had been removed to a point ft. west of fifth avenue, settlement was detected in the street surface above. bench excavation was suspended and a section of the permanent lining, ft. long, was placed. the space between the lining and the beams and between the beams and the roof was filled with rubble masonry. grout pipes were built into the masonry and later all voids were filled with grout. fig. , plate lix, shows the first section of the concrete lining completed and part of the rubble in place; and fig. , plate lix, shows details of the work above the tunnels. a second section of bench was next removed and more lining was placed. work was continued in this way until all the roof at the old three-track headings had been secured. in this portion of the work the posts were embedded in the concrete. between fifth and sixth avenues there were two more sections of bad rock where it was necessary to support the roof with steel beams. at these latter points there were no complications with the excavation for the three-track tunnel, and the work was much simpler. to avoid leaving the center posts in the permanent work, two rows of temporary posts were placed, as shown by fig. , plate lx, the center wall and skewback were built, and the posts were removed, as shown by fig. , plate lx, before placing the remainder of the lining. in d street the normal progress of the excavation was frequently interrupted by encountering soft and unsound rock. in the excavation between the east river and the intermediate shafts it was possible to overcome these conditions by temporarily narrowing the excavation on one side and supporting the roof on by -in. transverse timbers caught in niches in the rock at the sides, leaving sufficient room for the steam shovel to work through. in order to save time, the height of the excavation was not increased before placing these timbers, so that, previous to the concreting, they all required to be raised to clear the masonry lining and were then supported on posts on the center line between the tunnels. this permitted the remainder of the excavation to be made, and such additional timbering as was required was placed. at most of these sections a brick arch and water-proofing were used, on account of the presence of water. in certain places the center line posts were buried in the core-wall, and, in order to permit the placing of the water-proofing, were then cut off one by one flush with its top as the load was transferred to the completed masonry. in other cases the load was transferred to posts clear of the masonry and the center line posts were entirely removed. under such conditions the normal concrete methods, to be described later, could not be used, and special forms were substituted. [illustration: fig. . construction of twin tunnels, through excavation started for three-track tunnel in d street near th avenue] in this section of the work the most serious difficulties were encountered near fourth avenue a short distance east of the intermediate shaft, and beneath the site of the old pond shown on general viele's map. the rock cover was known from the boring to be very thin, and the presence of the subway overhead caused some anxiety. the excavation was at first taken out to practically full width and timbered, but the rock became so treacherous that the heading was narrowed to a width sufficient for one tunnel only. with this span the rock in the roof held without timbering. as the masonry lining approached, sufficient trimming was done to permit the placing of the core-wall and one arch. above the completed core-wall and brick arch the voids were filled solid with rubble masonry to give an unyielding support to the roof. the excavation of the remaining width of tunnel was then undertaken. near the west side of fourth avenue, the excavation broke out of rock at the top, and fine sand and gravel with a large quantity of water were encountered. the work of excavation was arduous, and proceeded very slowly, on account of the care with which it was executed. only a small amount of sand entered the tunnel, but the lining was placed as soon as the excavation was completed. rubble masonry packing and grout ejected through pipes built into the arch were used to fill the voids above the roof. as a further precaution against the settlement of the subway, -in. pipes were washed down from the street above the point where soft ground was exposed in the roof of the tunnel, and through them grout was forced into the ground at various depths. careful levels show that no settlement of the subway has taken place. west of the intermediate shaft the tunnel was excavated for full width until bad rock was encountered about ft. west of madison avenue. (see general viele's map, plate ix.) timbering was used for a short distance, and then the heading and bench were narrowed to ft., and steam-shovel excavation was abandoned. as the heading advanced the rock grew steadily softer, the difficult conditions in this locality culminating when a slushy disintegrated feldspar was met, requiring poling and breasting. thereafter the rock improved markedly, but near the east side of fifth avenue its thickness above the roof was found to be only - / ft., and the advance was stopped, pending a decision as to a change of plan. [illustration: plate lx, fig. .--double row of posts under i-beams, supporting roof in bad rock section.] [illustration: plate lx, fig. .--center wall and skewback under i-beams, after removal of double row of posts.] [illustration: plate lx, fig. .--timbering in full-width heading of three-track tunnel.] [illustration: plate lx, fig. .--underpinning walls in open-cut section.] after some delay, an exploration drift, similar to the one already described, was driven through to sixth avenue, and a change in plan was made, substantially the same as for the d street tunnels. enlargement to full size was at once started, but, for ft. the rock was very soft and poor, and required extremely careful handling. the exploration drift was widened out to the full twin-tunnel width, and i-beams were placed and supported, in much the same manner as in d street. the rock was so soft that it was frequently necessary to drive poling boards ahead as the face was mined out with picks and shovels. the load was very heavy, and the work the most difficult encountered in the tunnels. after this stage of the enlargement was reached, the excavation of the bench and the placing of the lining proceeded alternately, with the i-beams temporarily supported on long posts while the concrete core-wall was being built. considerable settlement took place while shifting the posts, and eventually showed on the street surface and in the adjacent sidewalk vaults, but no damage was done to the structural portions of the buildings. while the above work had been going on westward from fifth avenue, the excavation of the twin tunnel eastward from the end of the open-cut section at sixth avenue had been proceeding rapidly, and, toward the end of the difficult fifth avenue work, it was being attacked from both directions. progress of excavation. owing to the numerous sections of poor rock, interspersed throughout the work with stretches of sound rock, the progress of the excavation was very irregular, especially in d street. the rate of excavation in good ground is shown in table . in the sections of bad ground, the operations of excavation, timbering, and lining were often carried on alternately, and it is impracticable to include them in the table. table .--progress and methods of excavation in good ground. thirty-third street. ============================================================ | | | -----------------------------+--------+--------------------+ | | | | | | type of excavation. |tunnels.| worked from: | | | | | | | -----------------------------+--------+--------------------+ full-sized single tunnel | b | st ave. shaft. | | | | full-sized single tunnel | a | st ave. shaft. | | | | full-sized twin tunnel |a and b | st ave. shaft. | | | | | | | | | | full-sized twin tunnel |a and b |intermediate shaft. | | | (west of shaft.) | | | | | | | full-sized twin tunnel |a and b |intermediate shaft. | | | (east of shaft.) | | | | | | | full-sized twin tunnel |a and b |intermediate shaft. | | | (east of shaft.) | | | | | | | exploration drift |a and b |intermediate shaft. | | | (west of shaft.) | | | | twin tunnel. enlargement |a and b | west shaft. | of exploration drift | | (east of shaft.) | =============================+========+===================== ====================================================================== | | | | ----------------------------------+--------+------------+------------+ | | length | average | dates. | time | tunnel | advance | ----------------------------------|elapsed,| excavated, | per day, | | | in | in | in | from | to | days. |linear feet.|linear feet.| ----------------------------------+--------+------------+------------+ feb. , . |may , . | | | . | | | | | | feb. , . |apr. , . | | | . | | | | | | aug. , . |jan. , . | | | . | | | | | | | | | | | | | | | | apr. , . |oct. , . | | | . | | | | | | | | | | | | | | | | apr. , . |oct. , . | | | . | | | | | | | | | | | | | | | | nov. , . |dec. , . | | | . | | | | | | | | | | | | | | | | mar. , . |july , . | | | . | | | | | | | | | | | sept. , . |dec. , . | | | . | | | | | | ===============+==================+========+============+============= ===================================================== ----------------------------------------------------- methods and conditions. ----------------------------------------------------- top heading and bench. muck loaded by hand. " " " " " " " " top full-width heading and bench. muck loaded by steam shovel. working exclusively on this heading. top center heading and bench. muck loaded by steam shovel. working alternately in headings east and west of the shaft. top center heading and bench. muck loaded by steam shovel. working alternately in headings east and west of the shaft. top full-width heading and bench. muck loaded by steam shovel working exclusively on this heading. exploration drift about ft. by ft. mucking by hand. fourteen timber bents were placed in march, and seven in april, . drift excavated to full width and bench. muck loaded by steam shovel. ===================================================== thirty-second street. ============================================================ | | | -----------------------------+--------+--------------------+ | | | | | | type of excavation. |tunnels.| worked from: | | | | | | | -----------------------------+--------+--------------------+ full-sized single tunnel | c | st ave. shaft. | | | | full-sized single tunnel | d | st ave. shaft. | | | | full-sized twin tunnel |c and d | st ave. shaft. | | | | | | | | | | narrowed twin tunnel | c |intermediate shaft. | | | (east of shaft.) | | | | | | | narrowed twin tunnel | c |intermediate shaft. | | | (east of shaft.) | | | | | | | | | | | | | full-sized twin tunnel |c and d |intermediate shaft. | | | (west of shaft.) | | | | exploration drift |c and d |intermediate shaft. | | | (west of shaft.) | | | | twin tunnel. enlargement }|c and d |{ eastward from | of exploration drift }| |{ open cut. | | | | twin tunnel. enlargement }|c and d |{ eastward from | of exploration drift }| |{ open cut. | | | | =============================+========+===================== ==================================+========+============+============= | | | | ----------------------------------+--------+------------+------------+ | | length | average | dates. | time | tunnel | advance | ----------------------------------|elapsed,| excavated, | per day, | | | in | in | in | from | to | days. |linear feet.|linear feet.| ----------------------------------+--------+------------+------------+ jan. , .|apr. , . | | | . | | | | | | jan. , .|apr. , . | | | . | | | | | | {may. , .|july , .[e]}| | | . | {aug. , .|nov. , . }| | | | | | | | | | | | | | mar. , .|may , . | | | . | | | | | | | | | | | | | | | | {may , .|july , .[e]}| | , | . | {july , .|july , . }| | | | {aug. , .|nov. , . }| | | | {jan. , .|feb. , . }| | | | {feb. , .|mar. , . }| | | | | | | | | dec. , .|may. , . | | | . | | | | | | | | | | | feb. , .|sept. , . | | , | . | | | | | | | | | | | }feb. , .|feb. , . | | | . | } | | | | | | | | | | }feb. , .|apr. , . | | | . | } | | | | | | | | | | ====================================================================== [footnote e: time and distance omitted while working through timbered stretches.] ======================================================= ------------------------------------------------------- methods and conditions. ------------------------------------------------------- top heading and bench. muck loaded by hand. " " " " " " " " double heading and bench. muck loaded by steam shovel. stretches aggregating ft. narrowed to about ft. and later enlarged are included. excavation about ft. wide. top full-width heading and bench. muck loaded by hand. steam shovel not installed. excavation about to ft. wide. top full-width by hand and part by steam shovel. double heading and bench. part of the muck handled by hand and part by steam shovel. exploration drift about ft. by in. muck loaded by hand. ft. timbered. at portal of twin tunnels. drift excavated to full width and bench. muck loaded by hand. ft. timbered. drift excavated to full width and bench. muck loaded by steam shovel. full-width tunnel timbered for ft. independently of the main excavation. ======================================================= three-track tunnel excavation. when it became evident that the work through the fifth avenue section would be extremely slow, shafts were sunk in each street between sixth and seventh avenues. the shafts, as shown on plate xiv, were located in the streets, but in such a way as to block only half of the roadway. at the same time it was decided to construct in open cut about ft. of the three-track tunnel at the west end of the contract in d street, where the rock surface was below the top of the tunnel. it was hoped that the remainder of the work could be built without opening the street, but further investigation showed that this was impracticable, and eventually all the three-track tunnel in d street, except ft. east of the shaft, was built in open cut. _thirty-second street work in tunnel._--following the sinking of the shaft, a drift was driven across the street at the crown of the tunnel, and a top heading on the south side was excavated in both directions. frequent cross-drifts to the north side showed that the rock was nowhere very sound and that, except for a short distance east of the shaft, it was distinctly unfavorable for the wide three-track excavation. in this stretch the north ends of these cross-cuts were connected by a second heading, and wall-plates and sets of three-segment arch timbering were set up to support the roof of the drifts. the cross-cuttings were gradually widened and timbered until the entire excavation had been made down to the level of the wall-plates, as shown in fig. , plate lx. the bench was then excavated in two lifts, leaving the wall-plates supported on narrow longitudinal berms, which were removed in short sections to permit the placing of posts under the wall-plates. _thirty-second street open-cut work._--before actual open-cut excavation was started, all buildings facing it were underpinned to rock. for this purpose, a trench was dug along the face of the buildings and of the same depth as their cellars. holes were cut in the front foundation walls through which long needle-beams (fig. , plate lx) were inserted and jacked up on blocking placed on the cellar floor and in the trench, until the weight of the building had been taken off its foundations. a close-sheeted trench was then sunk to rock under the front building walls, and a light rubble masonry retaining wall was built in it to support the building permanently. frequently, the excavation for the underpinning wall, which was taken out in sections from to ft. long, and in places was carried to a depth of ft., was very troublesome on account of the large quantity of water encountered and the fineness of the sand, which exhibited a tendency to flow when saturated. the elevated railroad columns in sixth avenue, near the north and south lines of d street, were underpinned in a manner similar to the building foundations, while those on the center line of the street were supported by girders riveted to them close under the track level. the girders in turn were supported on posts footed on the new underpinning of the adjacent columns. on the completion of the tunnels, concrete piers were built up from the roof of the tunnel to form a permanent foundation for the center-line columns. the area to be excavated under sixth avenue was enclosed by a rubble masonry retaining wall constructed in a trench. open-cut excavation was started by planking over the street on stringers resting on transverse by -in. caps. the caps were gradually undermined and supported on temporary posts which were then replaced by short posts resting on by -in. sills about ft. below the cap. the operation was then repeated and the sill was supported on another set of short posts resting on a second sill. when the excavation had been carried down in this manner to the level of the top of the tunnel, diagonal by -in. timbers were cut in between the posts and sills to form a species of double a-frame, the legs of which rested in niches cut in the rock and on posts carried up the face of the underpinning wall, and the whole was stiffened with vertical tie-rods. this construction is shown by fig. , plate lxii. the brick sewer was replaced temporarily by one of riveted steel pipe. this pipe and the water and gas pipes and electric conduits were suspended from the timbers as the pipes were uncovered. excavation in rock was made by sinking a pit to sub-grade for the full width of the tunnel and advancing the face of the pit in several lifts, the muck being blown over the slope and loaded into buckets at its foot. the work was attacked at several places simultaneously, and the spoil was hoisted by derricks located at convenient points along the side of the cut. _thirty-third street work in tunnel and open cut._--the west d street shaft was similar to the one in d street, and was sunk during february, march, and april, , through ft. of earth, ft. of soft rock, and ft. of fairly hard rock. it was necessary to timber heavily the upper ft. of the shaft. the timber later showed evidences of severe strain, and had to be reinforced. [illustration: plate lxi.--excavation and timbering in heavy ground of three-track tunnel of d st.] as soon as the shaft excavation was deep enough, a drift was driven part way across the tunnels, and top headings were started both east and west to explore the rock. the heading to the west was divided into two drifts, as shown on plate lxi. these two drifts were continued to the west end of the contract, and were then enlarged to a full-sized heading and timbered, as shown on plate lxi and fig. , plate lx. the rock near the shaft contained many wet rusty seams, and settlement was detected in the segmental tunnel timbering soon after the widening of the heading was completed. short props were placed under the timbers, and the street surface was opened with a view of stripping the earth down to the rock and thus lightening the load on the timbering. street traffic was maintained on a timber structure with posts eventually carried down to the rock surface, and the walls of the buildings on the north side of the street were underpinned to rock. the settlement of the tunnel timbering was checked for a time, and the bench was excavated as shown on plate lxi. in this work the cut in the center was first made, and the short props were replaced by struts, as shown; after this the berms were removed and the side posts were placed. while building the brick arches, holes were left in the masonry around the struts. after the masonry had hardened, piers were built on the arches to support the segmental timbers. the struts were then removed and the openings filled with masonry. the voids above the arch were packed with rock and afterward thoroughly grouted. the timbers near the shaft continued to settle, and, although they had been placed from to in. above the level of the top of the masonry, by october st, they encroached in. within the line of masonry. it was then decided to remove the rock for a distance of ft. west of the shaft, and build this portion of the tunnel in open cut. the posts supporting the deck forming the street surface were replaced by an a-frame structure similar to that developed for the d street open cut, without interruption of the street traffic. after making the open cut to the westward of the shaft, there was a slip in the rock north of and adjoining the shaft. fortunately, the timbers did not give way entirely, and no damage was done. the open cut was extended eastward for a distance of ft., making the total length of tunnel built in open cut on this street ft. east of the shaft, for a distance of about ft., the rock was broken and could not be excavated to full size without timbering the roof, but between this section of poor rock and those already mentioned in connection with the work at fifth avenue, there was a stretch of ft. of good rock where all the spoil was handled with a steam shovel. twin-tunnel lining. the masonry lining for the tunnels was not started until the late fall of , after excavation had been in progress for a year and a half. at that time concreting was started in the single tunnels westward from the first avenue shafts, and by spring was in full swing in the twin tunnels. the plans contemplated the use of a complete concrete lining except where large quantities of water were encountered; in which case the arches, beginning at a point ° above the springing line, were to be built of vitrified paving brick. by reference to plate xii it will be seen that the water-proofing, which in the concrete-roof tunnels extended the full height of the sides to the ° line, was carried in the brick-roof tunnels completely around the extrados of the arch. the cross-sections also show the location of the electric conduits which were buried in the mass of the side and core-walls and which limited the height to which the concrete could be carried in one operation. the same general scheme of operations was used wherever possible throughout the twin-tunnel work, but was subject to minor modifications as circumstances dictated. concrete was first deposited in the bottom, to the grade of the flow line of the drains; after it had set, collapsible box forms, of -in. plank with -in. plank tops, were laid on it to form the ditch and the shoulders for the flagstone covers. the track, which had previously been blocked up on the rock between the ditches, was raised and supported on the ditch boxes above the finished floor level. at the same time, light forms were braced from the ditch boxes to the grade of the base of the low-tension and telephone-duct bank. after depositing the concrete to this level, the telephone ducts were laid. the forms for the water-proofing or sand-wall up to the ° line and for the main side-walls and core-walls were built in -ft. panels and were supported on carriages, which, traveling on a broad-gauge track above the ditches, moved along the tunnel, section by section, as the work advanced. the panels were hung loosely from joists carrying a platform on the top chord of the carriage trusses, and were adjusted transversely by bracing and wedging them out from the carriage. the small forms for the refuge niches, ladders, etc., were collapsible, and were spiked to the main panel forms just previous to the deposition of the concrete. the concrete was deposited from the platform on top of the carriage, to which the cars were elevated in various ways. plate lxi shows the details of the carriages, and is self-explanatory. the concrete for the sand-walls and the core-wall, to the level of the sidewalk, was deposited at the same time; two carriages in each tunnel, placed opposite each other, forming a -ft. length, were used at each setting. the floor section of the -in. tile drains had been laid with the floor concrete, and, as the sand-wall concrete was deposited, the drains were brought up simultaneously, broken stone being deposited between the tile and the rock to form a blind drain and afford access to the open joints of the tile for the water entering the tunnel through seams in the rock. the drains were spaced at intervals not exceeding ft., depending on the wetness of the rock, and were placed at similar intervals in the core-wall under the lowest projecting points of the rock on the center line between the tunnels. a small ditch lined with loose -in. vitrified half pipe was provided in the top of the sand-wall to collect the water from the extrados of the arch and lead it to the top of the drains. great difficulty was experienced in maintaining these drains clear, and, on completion of the work, a large amount of labor was expended in removing obstructions from the floor sections, the only portion then accessible. after water-proofing the sand-walls and laying the low-tension ducts, a second pair of carriages, with panels on one side only, for ft. of side-wall and skewback to the ° line, were set and braced against the core-wall. these forms are shown in connection with the carriage on plate lxi. they were concreted to the base of the high-tension duct bank, and, after the concrete had hardened and the bank of ducts had been laid, the concreting was completed in a second operation. in places where the roof was supported temporarily by posts and heavy timbering, such as at fifth avenue, the form carriages could not be used, and special methods were devised to suit the local conditions. usually, the panels were stripped from the carriages and moved from section to section by hand, and, when in position, were braced to the timbering. the arch centers were built up of two by by / -in. steel angles, and, when set, were blocked up on the sidewalks opposite each other in the two tunnels. a temporary platform was laid on the bottom chord angles of the ribs, on which the concrete was dumped, the same as on the form carriages. the lagging used was by -in. dressed pine or spruce ft. long, and was placed as the concreting of the arch proceeded above the ° line on the side-wall and above the sidewalk on the core-wall. after the arch had reached such a height that the concrete could not be passed over the lagging directly from the main platform, it was cast on a small platform on the upper horizontal bracing of the centers, shown in fig. , plate lix, and was thence shoveled into the work. in the upper part of the arch the face of the concrete was kept on a radial plane, and, when only ft. remained to be placed, it was keyed in from one end, the key lagging being set in about -ft. lengths. the arches were concreted usually in -ft. lengths. where brick arches were used, the core-wall skewback was concreted behind special forms set up on the sidewalks, or the arch ribs and lagging were used for forms, and the brick arch was not started until after the concrete had set. in laying the brick in the arch, the five courses of the ring were carried up as high as the void between the extrados and the rock would permit and still leave a working space in which to place the water-proofing. this was usually not more than ft., except on the core-wall side. the felt and pitch water-proofing was then laid for that height, joined to the previous water-proofing on the side-walls, and was followed by the brick armor course over the water-proofing and by the rock packing, after which another lift of brick was laid and the operations were repeated. the large void (fig. , plate lxii) above the core-wall gave convenient access for working on top of the adjacent sides of the roof, and the keying of the arches and the water-proofing and rock packing above the core-wall were usually carried on from that point, the work progressing from one end. the concrete for all work above the floor was dumped on the platform of the carriages, to which it was transported in the early part of the work in cars running on a high-level track laid on long ties, resting on the finished sidewalks. this arrangement, although requiring a large amount of timber for the track, permitted the muck to be carried out on the low-level track without interference. later, when the advance of the heading had ceased and the heavy mucking was over, all concrete was transported on the floor level, and the cars were lifted to the carriage platforms by elevators and were hauled by hoisting engines up a movable incline. the latter method is shown by fig. , plate lix. _water-proofing._--the water-proofing referred to above was in all cases felt and pitch laid with six thicknesses of felt and seven of pitch. the sub-contractor for the work was the sicilian asphalt paving company. all joints were lapped at least ft., and, where work was suspended for a time and a bevel lap could not be made, the edges of the felt were left unpitched for ft. and the newer work was interlaced with the old. this method was not always successful, however, on account of the softening of the unpitched felt on long-continued exposure to the water. the felt used was mainly "tunaloid," together with some "hydrex." it weighed about lb. per sq. ft. when saturated and coated on one side only, and contained about % of wool. the coal-tar pitch used had a melting point of ° fahr. after the completion of the tunnel, the concrete arch showed some leakage and in places unsightly lime deposits. it was determined to attempt to stop these leaks by the application of a water-proof cement coating on the intrados of the arch. extended experimental application of two varieties of materials used for this purpose--"hydrolithic" cement and the u. s. water-proofing company's compound--have been made with apparent success up to the present time, and the results after the lapse of a considerable period are awaited with interest. _duct laying._--the position of the electric conduits, buried in the heart of the concrete walls, interfered greatly with the economical and speedy placing of the lining, and their laying proved to be one of the most troublesome features of the work. the power conduits were single-way, with the bank for high-tension cables separated in the side-walls from the low-tension bank, as shown on plate xii. the conduits for telephone and telegraph service were four-way, and were located in the core-wall. all ducts had / -in. walls and a minimum clear opening of - / in. square, with corners rounded. they were laid with joints broken in all directions, and in about / -in. beds of : - / mortar. flat steel bond-irons, by / in., with split and bent ends, were placed in the joints at intervals of ft. and projected into the concrete in. on each side, tying together the concrete on opposite sides of the ducts. the joints were wrapped with a -in. strip of -oz. duck saturated with neat-cement grout, and, in addition, the power conduits were completely covered with a / -in. coat of mortar to prevent the intrusion of cement and sand from the fluid concrete. the four-way conduits were plastered only over the wraps. splicing chambers were provided at intervals of ft. [illustration: plate lxii, fig. .--water-proofing over brick arches.] [illustration: plate lxii, fig. .--trestle used in concreting in three-track tunnel.] [illustration: plate lxii, fig. .--method of street support over open-cut excavation.] [illustration: plate lxii, fig. .--junction of twin and three-track tunnels.] three-track tunnel lining. in the three-track tunnels, a heavy brick arch was used for those portions constructed in tunnel, while, in the open-cut sections, the roof was of concrete. both were completely water-proofed on the roof and sides, and in the tunnel sections the space above the brick roof was filled with rock packing. on account of the unstable nature of the rock encountered throughout, the voids in the packing were afterward filled with grout. by reference to the cross-sections, plate xii, it will be seen that the haunches of the arch were tied together by steel i-beams anchored in the concrete, with the object of making the structure self-supporting in the event of the removal of the adjacent rock for deep cellar excavations. this construction materially influenced the contractor's method of placing the masonry lining. after depositing the floor concrete, by the same method that was used in the twin tunnels, a timber trestle (fig. , plate lxii) was erected to the height of the underside of the i-beam ties, the posts being footed in holes, about in. deep, left in the concrete floor to prevent slipping. in the open-cut sections the sand-wall forms were of undressed plank tacked to the studding and braced from the trestle; in the tunnel section they were spiked to the face of the posts supporting the timbering. the side-wall forms were made up in panels about by ft., and were clamped to studs by u-shaped irons passing around the stud and bolted to the cleats on the back of the panels, the studs being braced from the trestle. the side-wall concrete was deposited in three sections. the first was brought up just above the sidewalk and formed the bench for the high-tension ducts; the second carried the wall up to the springing line. before placing the third section the i-beam ties were set in position (fig. , plate lxii) on top of the trestle, and the reinforcing rods in the haunch of the arch were hung from them. the concrete was carried up to a skewback for the arch, as shown in the brick-roof cross-section (plate xii) and embedded the ends of the ties. the centers for the arches stood on the i-beam ties, and the tops of the hangers, for the permanent support of the ties near their center, were inserted through the lagging. the brick arch, water-proofing, and rock packing were laid up in lifts, in the same manner as in the twin tunnel, with grout pipes built in at intervals of about ft. the concrete arch was placed in sections, from to ft. in length, with a rather wet mixture and a back form on the steep slope of the extrados. the concrete for the sand-walls and lower part of side-walls was handled on tracks and platforms laid on cantilever beams at mid-height of the trestle, as shown by fig. , plate lxii. for the walls above the springing line, the tracks were laid on top of the i-beam ties, and some of the arch concrete, also, was delivered from the mixer at that level and hauled up an incline to the level of the top of the arch. by far the greater part, however, was turned out from mixers set on the completed arch, and was transported on tracks hung in part from the street timbering. _completion._--except in the heavily-timbered portions, such as at fifth avenue, where the load had to be transferred from posts to the completed masonry section by section, the lining of the tunnels presented no special difficulty. the large number of small forms to be set, and the mutual interference of the concreting and duct-laying operations proved to be the most troublesome features of the work. the restoration of the streets, public utilities, etc., at the open-cut sections was a slow and tedious operation, but the tunnels themselves were completed in march, , years and months after the inception of the work. the finished tunnels are shown by the photograph, fig. , plate lxii, taken at the junction of the twin and three-track types. footnotes: [footnote a: presented at the meeting of december st, .] [footnote b: of the paper by mr. noble.] [footnote c: of the paper by mr. noble.] [footnote d: of the paper by mr. noble.] american society of civil engineers instituted transactions paper no. the new york tunnel extension of the pennsylvania railroad. the east river division. by alfred noble, past-president, am. soc. c. e. a general outline of the work included in this division has been given by general c. w. raymond, m. am. soc. c. e., in the first paper of the series. the few pages following are intended only as a note to connect his paper with the more detailed descriptions of the execution of the work, which will be supplied by the resident engineers in immediate charge. soon after the company's project was made public, in the latter part of , borings were begun in the east river, and a few weeks later in manhattan and long island city. a preliminary base line was measured on the manhattan side, and temporary transit stations were established on buildings from which all borings in the river were located. the river borings were all wash-borings made from a pile-driver boat. after the results were plotted on the map, contour lines were drawn to indicate the rock surface, and profiles along the tunnel lines were plotted from the contours; as the borings were preliminary to the final location of the tunnels, and in many cases at some distance from the tunnel lines, considerable divergence from the actual rock surface was expected, and realized in a few places, yet on the whole the agreement was very good. the borings revealed two depressions or channels where the rock surface passed below the grade of the projected tunnels, these depressions being separated by a rock reef which extends down stream from blackwell's island. in d and d streets in manhattan, borings were made from the river to the station site at intervals of about ft., wash-borings and core-borings alternating. in long island city, where the tunnel lines were to pass diagonally under the passenger station building and passenger yard of the long island railroad and under streets and private property, the arrangement of borings was less regular, although the alternation of wash-borings and core-borings was carried out as far as practicable. after the final location of the work, additional borings were made, particularly on shaft sites and also along the approaches and in the sunnyside yard, long island city. a triangulation was carried across the river with a measured base on each side. it was impossible to measure directly between the extremities of either base. the bases were measured with -ft. steel tapes, supported every ft., stretched with a uniform pull, and frequently compared with standardized tapes. on account of the crowded condition of the streets during the hours of daylight and evening, most of the work was done between p. m. and a. m. similar measurements were made in the streets along the tunnel lines. angle readings were repeated many times, as is usual in such work. fig. shows the triangulation, the street measurements being omitted. levels were first transmitted across the river by simultaneous observations of the river surface; then by several repetitions, across blackwell's island and the narrow channels on each side, where the longest sights were about ft.; and, finally, by several lines through the tunnel of the east river gas company at st street. the franchise granted by the city of new york provided for the sale to the railroad company of the portions of d street between seventh and eighth avenues, and between eighth and ninth avenues. later, the company acquired by purchase the portion of d street between ninth and tenth avenues. the franchise granted sub-surface rights under streets around the station site to within ft. of the street surface under seventh, eighth, and ninth avenues; to within in. of the street surface under st and d streets, except that, under the sidewalks opposite the station, that is to say, the south sidewalk in st street and the north sidewalk in d street, the construction must be at least ft. below the street surface. in carrying out the work, full use of these rights was made under eighth avenue, but only under such portions of seventh and ninth avenues as were indispensable for access by trains to the station area. it was not practicable to make full use of the rights granted under st and d streets without incurring great expense for supporting adjacent buildings or for injuries to them, and, after careful consideration, the arrangement shown in the plans was decided on, making about % of the sub-surface area under these streets available at track level. [illustration: fig. .--triangulation system east river tunnel] the work of the east river division at this site embraced the excavation to the depth necessary for railroad tracks, and the building of a retaining wall extending in st street from the east side of ninth avenue to the west side of seventh avenue, thence northward along seventh avenue for a distance of . ft.; also a retaining wall in d street from the west side of seventh avenue to the east side of ninth avenue, and thence southward along ninth avenue for a distance of . ft. this work was placed under contract june st, , with the new york contracting and trucking company, and later assigned by that company to the new york contracting company-pennsylvania terminal, and was carried out under the direction of george c. clarke, m. am. soc. c. e., as resident engineer, by whom it will be described in detail. [illustration: plate ix.--map of portion of manhattan island from d to th streets, showing former topography from map made by gen. egbert l. viele in ] the station tracks leading eastward from the station will converge under seventh avenue and for some distance farther east, and pass into two three-track tunnels, one under d street and the other under d street, at the respective distances of and ft. from seventh avenue. a typical cross-section of the three-track tunnel is shown on plate xii. the converging sections were considered as easterly extensions of the station, and were not included in the east river division. within a few hundred feet (plate xiv), the tracks are reduced to two, each passing into a single tube, the two tunnels under each street being formed in one excavation, the distance between center lines of tunnels being ft. in. this construction has been termed a twin tunnel, and a typical cross-section is shown on plate xii. the tunnels continue on tangents under the streets to second avenue where they curve to the left by ° ' curves, passing under private property, gradually diverging and passing through shafts just east of first avenue. about ft. west of the shaft, the divergence of the two lines from each street becomes sufficient to leave a rock dividing wall between them, and thence eastward each tunnel is formed in a separate excavation. a typical cross-section of the two separated tunnels is shown on plate xii. it thus appears that eastward from the station the lines constitute a four-track railroad, each track being in a separate tunnel; for convenience of the work these lines were designated _a_, _b_, _c_, and _d_, from north to south. [illustration: plate x.--manhattan shaft, lines _a_ and _b_] at an early date, when the organization of the engineering staff was taken up, charles l. harrison, m. am. soc. c. e., was appointed principal assistant engineer. he was directly in charge of all parts of the work, and all resident engineers reported to him. george leighton, m. am. soc. c. e., was placed in charge as resident engineer of the d street lines from the west end of the three-track tunnel to the shaft and also eastward from the shaft under east river. as he was not then able to endure the effects of compressed air, the work under the river was transferred to james h. brace, m. am. soc. c. e., as resident engineer. before the completion of the land tunnels under d street, mr. leighton accepted more responsible employment elsewhere, and mr. brace assumed charge of them also. francis mason, m. am. soc. c. e., was in charge as resident engineer of the d street lines during their entire construction, and also of the tunnels extending these lines eastward from the first avenue shaft under the river. the work just described as the d and d street lines, terminating at the easterly end at the first avenue shafts, was placed under contract on may th, , with the united engineering and contracting company. the plans then provided for three-track tunnels from the west end of the work under the contract eastward , ft. in d street and , ft. in d street to the west line of fifth avenue, with a descending grade of . %; this was to constitute, in a degree, an extension of the station, where trains could stand without brakes while awaiting signals to proceed to or from the station. from fifth avenue eastward to the lowest point under the river, the grade was to be . % on all lines. later, during construction, when excavating westward under d street from fifth avenue, the surface of the rock was broken through, disclosing quicksand; within the next few days trial drill holes through the tunnel roof at d street and fifth avenue showed a thin cover with quicksand above it. the conditions had been indicated in a general way by borings made before construction was begun, but they proved to be rather worse than anticipated. on the topographical map of manhattan island, made by general egbert l. viele in , is shown a watercourse which had its source near what is now broadway and th street, flowing thence along the west side and south end of murray hill, passing under the present site of the waldorf-astoria hotel, crossing d street at the point where the rock surface was broken through in the tunnel excavation, as above stated, crossing d street at its intersection with fifth avenue, where trial drilling showed thin rock cover over the tunnel excavation, passing thence eastward a short distance south of d street, which it recrossed near third avenue, and finally discharging into the east river near th street, and a little west of the present first avenue. the ancient creek apparently followed the course of a valley in the rock, the valley having become filled to a considerable depth with very fine quicksand. this concurrence of depressions in the rock surface with the watercourse shown on viele's map was noted in so many places and the difficulties of construction were so serious at these places, that a section of the map showing the old topography along and adjacent to the station and tunnel lines is reproduced in plate ix. [illustration: plate xi.--long island shaft. lines _a_ and _b_] the unfavorable conditions developed at fifth avenue affected both the construction of the tunnels and the maintenance of adjacent buildings. it would be necessary to construct the tunnels in open cut for a large part of the way westward, causing serious inconvenience to the public; the buildings were mostly of the older class, founded in earth, but there were several modern high buildings with foundations in the same material; some of these had been built since the tunnels were planned. in view of these added risks and the increased cost of construction, the value of the three-track construction was reconsidered, and two important changes were made in the plans. the first of these was to continue the twin tunnel westward to sixth avenue in d street, and to a point ft. west of sixth avenue in d street; the twin tunnel being - / ft. less in height than the three-track tunnel and ft. narrower, the change reduced the difficulties considerably. where the three-track tunnel was thus eliminated, there was no longer objection to a steeper grade, so that, going eastward from the station, a grade of . % in d street and . % in d street was substituted for the original . % grade. from the west line of fifth avenue eastward short sections with descending grades of . % connect with the original . % grade near madison avenue. the effect of these two changes--type of tunnel and grade--was to lower the roof of the tunnels at fifth avenue about ft., which made it practicable to avoid open cutting east of sixth avenue. a full account of the construction of the cross-town tunnels will be given by the resident engineers. permanent shafts were made on both sides of the east river, those in manhattan being located a few feet east of first avenue, and those in long island city being located, one in the so-called annex slip, the other in the pier just south of it. the two railroad lines coming from d street in manhattan, and curving to the left at second avenue, are about ft. apart between centers at first avenue, and it was convenient to make the shaft large enough to cover both lines. borings had shown that the excavation for the tunnels would break out of the rock about ft. east of first avenue. it was desirable to carry the tunnel excavation eastward from the shaft in normal air far enough to permit of building at least ft. of tunnel and installing air-locks, so that compressed air might be available when the rock surface was broken through. the location adopted, and shown on plate xiii, had the further advantages that the rock surface was several feet above the level of the top of the tunnels, and access to the river for receiving and discharging materials could be had without crossing any street. similar reasons governed the location of the north shaft for the lines from d street. on the long island side of the river there were only two feasible locations meeting these conditions, particularly in respect to a safe thickness of rock above the tunnels, one near the pierhead line, the other just outside the bulkhead line, and for many minor reasons the latter was preferable. the center lines of each pair of tunnels were ft. apart, and each shaft, therefore, was made to cross both lines of a pair, the same as on manhattan side of the river. it was not expected, however, that the long island shafts could be built conveniently or the tunnels begun from them in normal air. the decision to make the shafts of permanent construction was based not only on the desirability of having access to and egress from the tunnels near the banks of the river for convenience of the workmen or exit for passengers in case of accident, but to facilitate ventilation; these locations divide the entire lengths of tunnels east of the station into three parts, two of which were approximately , ft. each, and the other about , ft. the accident risk was believed to be very small, while much weight was given to the feature of facilitating ventilation. further studies have enhanced the importance attached to ventilation, and it is now intended to provide appliances for mechanical ventilation at all shafts. the plans of the shafts are shown on plates x and xi. the caissons for the shafts are of structural steel, with double walls, filled between with concrete, including a cross-wall between and parallel to the tunnels. all these structures were fitted for sinking with compressed air, if that should prove necessary. although borings had shown that rock would be found at all the shaft sites several feet above the tunnel level, it could not be determined in advance of excavation whether the caissons would have to be sunk to full depth; if sound, unfissured rock were found, the sinking could be stopped above the tunnel level; but, if not, the caissons, in any case, would have to be sunk far enough to permit placing a water-tight floor below the tunnels, and the tunnels themselves begun through openings in the side-walls of the caisson; such openings, therefore, closed by removable bulkheads, were provided in all caissons. [illustration: plate xii.--typical tunnel sections] as already stated, the grade of . % from fifth avenue eastward was fixed with reference to the lowest point of the river bed in order to give the requisite cover over the tunnels at the deepest point of the channel on the west side of the reef, where the river bottom was about ft. below mean high tide for a short distance. on the other hand, as the use of compressed air in building the tunnels was anticipated, an excessive depth below the water surface was to be avoided as far as possible; it was necessary, however, to continue the descending grade some further distance until the tunnels were mostly in rock, so that drainage sumps under the tunnels could be made readily. eastward from the sumps the tunnels had a rising grade of . % to the established bulkhead line on the long island side, giving a cover at the points where the tunnels enter rock, a short distance westward, of about ft. (if the dredging plane should be fixed at some future time at ft. below mean low tide, as may be reasonably anticipated). eastward from the bulkhead line, tunnels _a_, _b_, and _d_ have ascending grades of about . %, while tunnel _c_ rises at the rate of . % in order to effect a crossing over tunnel _b_ west of the portals. this feature was introduced in order to place the two west-bound tracks together through the sunnyside yard, and the heavier grade, being downward with the traffic, was not objectionable. the arrangement of grades and tracks in the approaches and in sunnyside yard would require the introduction of too much detail to be taken up here, but will be dealt with in the paper on the sunnyside yard. it was recognized from the inception of the project that the tunnels under the east river would be the most difficult and expensive section of the east river division. the borings had shown a great variety of materials to be passed through, embracing quicksand, coarse sand, gravel, boulders, and bed-rock, as well as some clayey materials. (see plate xiii.) the rock was usually covered by a few feet of sand, gravel, and boulders intermixed, but, in some places, where the rock surface was at some distance below the tunnel grade, the material met in tunneling was all quicksand; the nearest parallels in work previously done were some of the tunnels under the thames, particularly the blackwall tunnel, where open gravel was passed through. before the plans for the east river tunnels were completed, work had been resumed, after many years' interruption, in the old hudson river tunnels between th street, jersey city, and morton street, manhattan, and sand materials were passed through for a short distance. these experiences satisfied nearly all the engineers in any way connected with the work that the shield method was the most suitable for the east river tunnels, and the plans for the work were based on its adoption. (see plate xii for cross-sections, etc.) other methods, as stated by general raymond in the introductory paper, were advocated, particularly caisson constructions and the freezing process, the latter being urged very strongly, and, when proposals were invited, in october, , bidders were informed that alternative methods would be taken into consideration. bids were received and opened on december th, . only one bidder proposed to carry out the work on the basis of unit prices, but the prices were so low that the acceptance of the proposal was deemed inadmissible; no bid based on caisson methods was received; several offers were made to perform the work by the shield method, in accordance with the plans, for a percentage of its cost, and one was submitted, on a similar basis, covering the use of the freezing method. the firm of s. pearson and son, limited, of london, england, submitted a proposal for building the tunnels by the shield method, on a modification of the percentage basis, and as this firm had built the blackwall tunnel within the estimates of cost and was the only bidder having such an experience and record in work in any way similar to the east river tunnels, negotiations were continued between that firm and the railroad company. the original plans and specifications contemplated that all tunnels between the first avenue shafts in manhattan and east avenue in long island city would be shield-driven, and that work would proceed simultaneously eastward from the first avenue shafts and both eastward and westward from the long island city shafts located west of front street at the river, requiring twelve shields. when making their proposal, s. pearson and son, limited, suggested that shields might be started from the east end of the work and arrive at the front street shafts as soon as these shafts could be completed, and proposed sinking a temporary shaft transversely across all four lines near the east end of the work just west of east avenue, from which, within a short time, to drive toward front street by the use of shields. the railroad company accepted the suggestion for the additional shaft, although the greater part of the tunnels east of front street was built without shields. after several months of negotiation, a contract was entered into on july th, , with s. pearson and son, incorporated, a corporation of the state of new york organized by the english firm for the purpose of entering into and carrying out this contract. the main features had been agreed upon, and work had begun about two months before. the contract embraced the permanent shafts in manhattan and long island city, the tunnels between these shafts, and their extension eastward in long island city to east avenue, including in all about , ft. of single-track tunnels. the contract had novel features, and seemed to be peculiarly suitable for the unknown risks and the unusual magnitude of the work. a fixed amount was named as contractor's profit. if the actual cost of the work when completed, including this sum named as contractor's profit, should be less than a certain estimated amount named in the contract, the contractor should have one-half of the saving. if, on the other hand, the actual cost of the completed work, including the fixed sum for contractor's profit, should exceed the estimated cost named in the contract, the contractor should pay one-half the excess and the railroad company the other half; the contractor's liability was limited, however, to the amount named for profit plus $ , , ; or, in other words, his maximum money loss would be $ , , . any further excess of cost was to be borne wholly by the railroad company. the management of the work, with some unimportant restrictions, was placed with the contractor; the relations of the engineer, as to plans, inspection, etc., were the same as in ordinary work, and the interest of the contractor to reduce cost was the same in kind as in ordinary work. [illustration: plate xiii.--plan and profile. east river tunnels] on account of the extent of the work embraced in this contract, and the dangerous exposure to compressed air required in most of it, it was divided into three residencies; two of these, including also the cross-town tunnels, have been described; the third, with s. h. woodard, m. am. soc. c. e., as resident engineer, embraced all tunnels from the easterly end of the work near east avenue in long island city to the meeting points under the river and also the permanent shafts in long island city. a few months after the execution of the principal contract, the work to be done was extended eastward . ft., across east avenue. the extensions of the tunnels were built without cast-iron linings and with an interior cross-section of the same height as the tube tunnels, but somewhat narrower. the work was also extended westward from the first avenue shafts to include the excavation of top headings in each tunnel for a distance of ft. and an enlargement to full size for ft. the borings having shown that soft earth existed below the grade of the tops of the tunnel under the passenger station building of the long island railroad on the east side of front street, and that earth of varying character would be met in places beyond the station building under the railroad tracks in the passenger yard and the street car tracks in borden avenue, it had been decided, before proposals were invited, to extend the metal lining eastward to east avenue, at the east end of the work embraced in the original contract, where the rising tunnel grades approached the surface of the ground so closely that their further extension would be in open cut. in places where the tunnels were wholly in rock, the weight of the cast-iron tunnel lining was reduced %; where the surface of the rock was below the top of the tunnel, but above the axis, the reduction of weight was somewhat less, about %; notwithstanding these savings, the cost of the tunnels was probably increased by the use of the cast-iron lining; on the other hand, when passing through bad ground, a section of tunnel could be made absolutely safe more quickly by erecting the lining as soon as a length of a few feet of tunnel was ready; under a crowded passenger yard, this feature had great value. the execution of the work under this contract will be described fully by the resident engineers. the plant assembled by the contractors is believed to be the most extensive ever placed on a single piece of work, and will be described in detail by their managing engineer, henry japp, m. am. soc. c. e. for convenience in receiving materials to be used in construction, and to facilitate the disposal of excavated materials, one pier was leased on the east side of the hudson river, two on the west side of the east river and three on the east side. excavated materials from the station, the cross-town tunnels, and the river tunnels, were placed on barges furnished by mr. henry steers under several contracts embracing also the disposal of the materials. in the earlier part of the work, they were used as fill in the freight terminal of the pennsylvania railroad at greenville on the west side of the upper bay; when the fill at this place was completed, the materials were sent to the tunnel company's yard on the passaic, at harrison, n. j., and a small part to the embankment in the meadows division. on account of the occasional closing of the passaic by ice, this involved the possibility of, and to some extent resulted in, interruptions to the work of excavation. the contract for the cross-town tunnels carried an option in favor of the company to require the contractor for those tunnels to dispose of materials at a stated price, and in the latter part of , when the excavation in these tunnels was being pushed rapidly, the railroad company, unwilling to incur the responsibility for delays during the winter, availed itself of this option. the disposal of materials was an important part of the work, and will be dealt with more fully by the resident engineers. [illustration: plate xiv.--map and profile, cross-town tunnels] at the time the contract was made with s. pearson and son, incorporated, it had not been determined whether mechanical ventilation would be provided for the tunnels, and therefore the contract with that firm did not include the final concrete lining at the shafts, above the inverts of the tunnels. after the adoption of plans for mechanical ventilation, in the latter part of , the plans for lining the shafts with concrete, including flues for conducting air to the tunnels, and stairways for ingress and egress, were completed, and the work was placed under contract; it will be described in detail by f. m. green, assoc. m. am. soc. c. e. at the east end of the work under the pearson contract, the rising grade of the tunnels brought them so near the surface of the ground that their extension eastward could be carried out more readily in open cut than by tunneling. the locations of the portals could be varied somewhat, and they were built on rock which was found in rather narrow ridges at convenient places. tunnels _b_ and _d_ have a common portal; tunnels _a_ and _c_ have separate ones, the portal for tunnel _c_ being located about ft, west of the others as a result of its crossing over tunnel _b_, as already explained. eastward from the portals, the track system expands, in order to provide connections with the tracks of the long island railroad to and from long island city, with the new york connecting railroad and new england lines, and with the storage and cleaning yard known as the sunnyside yard extending to the west side of woodside avenue, - / miles east of the east river. (plate xv.) the yard and approaches are designed to avoid grade crossings by opposing trains. the various general features of the yard and tunnel approaches, bridge crossings, and street closings, have been described in sufficient detail by general raymond in the introductory paper. [illustration: plate xv.--plan and profile of lines _a_ and _b_, and sunnyside yards] for convenience in placing the work under contract, a line was drawn ft. west of thomson avenue, dividing the work east of that embraced in the pearson contract into two parts. the work west of the line was placed under the immediate direction of george c. clarke, m. am. soc. c. e., as resident engineer, with naughton company and arthur mcmullen, contractors; mr. louis h. barker was resident engineer of the part east of the dividing line, with the degnon realty and terminal improvement company as the principal contractors. the substructures of the several bridges in or across the yard were included in these contracts, but the superstructures were carried out by various bridge companies, and other minor features were executed by other contractors. more complete descriptions of the plans and of the execution of the work will be given by the resident engineers. american society of civil engineers instituted transactions paper no. the new york tunnel extension of the pennsylvania railroad. the east river tunnels.[a] by james h. brace, francis mason, and s. h. woodard, members, am. soc. c. e. this paper will be limited to a consideration of the construction of the tunnels, the broader questions of design, etc., having already been considered in papers by brig.-gen. charles w. raymond, m. am. soc. c. e., and alfred noble, past-president, am. soc. c. e. the location of the section of the work to be considered here is shown on plate xiii of mr. noble's paper. there are two permanent shafts on each side of the east river and four single cast-iron tube tunnels, each about , ft. long, and consisting of , ft. between shafts under the river, and , ft. in long island city, mostly under the depot and passenger yard of the long island railroad. this tube-tunnel work was naturally a single job. the contract for its construction was let to s. pearson and son, incorporated, ground being broken on may th, . five years later, to a day, the work was finished and received its final inspection for acceptance by the railroad company. the contract was of the profit-sharing type, and required an audit, by the railroad company, of the contractor's books, and a careful system of cost-keeping by the company's engineers, so that it is possible to include in the following some of the unit costs of the work. these are given in two parts: the first is called the unit labor cost, and is the cost of the labor in the tunnel directly chargeable to the thing considered. it does not include the labor of operating the plant, nor watchmen, yardmen, pipemen, and electricians. the second is called "top charges," a common term, but meaning different things to different contractors and engineers. here, it is made to include the cost of the contractor's staff and roving laborers, such as pipemen, electricians, and yardmen, the cost of the plant and its operation, and all miscellaneous expenses, but does not include any contractor's profit, nor cost of materials entering permanent work. the contractor's plant is to be described in a paper by henry japp,[b] m. am. soc. c. e., and will not be dealt with here. the contractors carried on their work from three different sites. from permanent shafts, located near the river in manhattan, four shields were driven eastward to about the middle of the river; and, from two similar shafts at the river front in long island city, four shields were driven westward to meet those from manhattan. from a temporary shaft, near east avenue, long island city, the land section of about , ft. was driven to the river shafts. [footnote a: presented at the meeting of december th, .] [footnote b: _transactions_, am. soc. c. e., vol. lxix. p. .] tunnels from east avenue to the river shafts. the sinking of the temporary shaft at east avenue was a fairly simple matter. rough by -in. sheet-piling, forming a rectangle, by ft., braced across by heavy timbering, was driven about ft. to rock as the excavation progressed. below this, the shaft was sunk into rock, about ft., without timbering. as soon as the shaft was down, on september th, , bottom headings were started westward in tunnels _a_, _b_, and _d_. when these had been driven about half the distance to the river shafts, soft ground was encountered. (see station , plate xiii.) as the ground carried considerable water, it was decided to use compressed air. bulkheads were built in the heading, and, with an air pressure of about lb. per sq. in., the heading was driven through the soft ground and into rock by ordinary mining methods. the use of compressed air was then discontinued. west of this soft ground, a top heading, followed by a bench, was driven to the soft ground at about station . tunnel _c_, being higher, was more in soft ground, and at first it was the intention to delay its excavation until it had been well drained by the bottom headings in the tunnels on each side. a little later it was decided to use a shield without compressed air. this shield had been used in excavating the stations of the great northern and city tunnel in london. it was rebuilt, its diameter being changed from ft. - / in. to ft. - / in. it proved too weak, and after it had flattened about in. and had been jacked up three times, the scheme was abandoned, the shield was removed, and work was continued by the methods which were being used in the other tunnels. the shield was rather light, but probably it would have been strong enough had it been used with compressed air, or had the material passed through been all earth. here, there was a narrow concrete cradle in the bottom, with rock up to about the middle of the tunnel, which was excavated to clear the shield, and gave no support on its sides. the shield was a cylinder crushed between forces applied along the top and bottom. with the exception of this trial of a shield in tunnel _c_, and a novel method in tunnel _b_, where compressed air, but no shield, was used, the description of the work in one tunnel will do for all. from the bottom headings break-ups were started at several places in each tunnel where there was ample cover of rock above. where the roof was in soft ground, top headings were driven from the points of break-up and timbered. as soon as the full-sized excavation was completed, the iron lining was built, usually in short lengths. it will be noticed on plate xiii that there is a depression in the rock between station and the river shafts, leaving all the tunnels in soft ground. as this was directly under the long island railroad passenger station, it was thought best to use a shield and compressed air. this was done in tunnels _a_, _c_, and _d_, one shield being used successively for all three. it was first erected in tunnel _d_ at station + . from there it was driven westward to the river shaft. it was then taken apart and re-erected in tunnel _c_ at station + and driven westward to the shaft. it was then found that there would not be time for one shield to do all four lines. the experience in tunnels _c_ and _d_ had proven the ground to be much better than had been expected. there was considerable clay in the sand, and, with the water blown out by compressed air, it was very stable. a special timbering method was devised, and tunnel _b_ was driven from station + to the shaft with compressed air, but without a shield. in the meantime the shield was re-erected in tunnel _a_ and was shoved through the soft ground from station + nearly to the river shaft, where it was dismantled. there was nothing unusual about the shield work; it was about the same as that under the river, which is fully described elsewhere. in spite of great care in excavating in front of the shield, and prompt grouting behind it, there was a small settlement of the building above, amounting to about - / in. in the walls and about in. in the ground floors which were of concrete laid like a sidewalk directly upon the ground. whether this settlement was due to ground lost in the shield work or to a compacting of the ground on account of its being dried out by compressed air, it is impossible to say. the interesting features of this work from east avenue to the river shafts are the mining methods and the building of the iron tube without a shield. excavation in all rock. where the tunnel was all in good rock two distinct methods were used. the first was the bottom-heading-and-break-up, and the second, the top-heading-and-bench method. the first is illustrated by figs. and , plate lxiii. the bottom heading, ft. wide and ft. high, having first been driven, a break-up was started by blasting down the rock, forming a chamber the full height of the tunnel. the timber platform, shown in the drawing, was erected in the bottom heading, and extended through the break-up chamber. the plan was then to drill the entire face above the bottom heading and blast it down upon the timber staging, thus maintaining a passage below for the traffic from the heading and break-ups farther down the line. starting with the condition indicated by plate xiii, the face was drilled, the columns were then taken down and the muck pile was shoveled through holes in the staging into muck cars below. the face was then blasted down upon the staging, the drill columns were set up on the muck pile, and the operation was repeated. this method has the advantage that the bottom heading can be pushed through rapidly, and from it the tunnel may be attacked at a number of points at one time. it was found to be more expensive than the top-heading-and-bench method, and as soon as the depression in the rock at about station was passed, a top heading about ft. high, and roughly the segment of a -ft. circle, was driven to the next soft ground in each of the four tunnels. the remainder of the section was taken out in two benches, the first, about ft. high, was kept about ft. ahead of the lower bench, which was about the remaining ft. high. excavation in earth and rock. about , ft. of tunnel, the roof of which was in soft ground, was excavated in normal air by the mining-and-timbering method. in the greater part of this the rock surface was well above the middle of the tunnel. the method of timbering and mining, while well enough known, has not been generally used in the united states. [illustration: plate lxiii] starting from the break-up in all rock, as described above, and illustrated on plate xiii, when soft ground was approached, a top heading was driven from the rock into and through the earth. this heading was about ft. high and about ft. wide. this was done by the usual post, cap, and poling-board method. the ground was a running sand with little or no clay, and, at first, considerable water, in places. all headings required side polings. the roof poling boards were about - / or ft. above the outside limit of the tunnel lining, as illustrated by figs. , , and , plate lxiii. the next step was to place two crown-bars, _aa_, usually about ft. long, under the caps. posts were then placed under the bars, and poling boards at right angles to the axis of the tunnel were then driven out over the bars. as these polings were being driven, the side polings of the original heading were removed, and the earth was mined out to the end of these new transverse polings. breast boards were set on end under the ends of the transverse polings when they had been driven out to their limit. side bars, _bb_, were then placed as far out as possible and supported on raking posts. these posts were carried down to rock, if it was near, if not, a sill was placed. a new set of transverse polings was driven over these side bars and the process was repeated until the sides had been carried down to rock or down to the elevation of the sills supporting the posts, which were usually about ft. above the axis of the tunnel. the plan then was to excavate the remainder of the section and build the iron lining in short lengths, gradually transferring the weight of the roof bars of the iron lining as the posts were taken out. this meant that not more than four rings, and often only one ring, could be built before excavation and a short length of cradle became necessary. before the posts under the roof bars could be built and the weight transferred to the iron lining, a grout dam was placed at the leading end of the iron lining, and grout was brought up to at least ° from the top. such workings were in progress at as many as eight places in one tunnel at the same time. where there was only the ordinary ground-water to contend with, the driving of the top heading drained the ground very thoroughly, and the enlarging was done easily and without a serious loss of ground. under these conditions the surface settlement was from in. to ft. under borden avenue, there was more water, which probably came from a leaky sewer; it was not enough to form a stream, but just kept the ground thoroughly saturated. there was a continued though hardly perceptible flow of earth through every crevice in the timbering during the six or eight weeks between the driving of the top heading and the placing of the iron lining; and here there was a settlement of from to ft. at the surface. tunneling in compressed air without a shield. when it became evident that there would not be time for one shield to do the soft ground portions of all four tunnels under the long island railroad station, a plan was adopted and used in tunnel b which, while not as rapid, turned out to be as cheap as the work done by the shields. figs. and , plate lxiii, and fig. , plate lxiv, illustrate this work fairly well. the operation of this scheme was about as follows: having the iron built up to the face of the full-sized excavation, a hole or top heading, about ft. wide and or ft. high, was excavated to about ft. in advance. this was done in a few hours without timbering of any kind; but, as soon as the hole or heading was ft. out, by -in. laggings or polings were put up in the roof, with the rear ends resting on the iron lining and the leading ends resting on vertical breast boards. the heading was then widened out rapidly and the lagging was placed, down to about ° from the crown. the forward ends of the laggings were then supported by a timber rib and sill. protected by this roof, the full section was excavated, and three rings of the iron lining were built and grouted, and then the whole process was repeated. [illustration: plate lxiv, fig. .--tunneling in compressed air without shield.] [illustration: plate lxiv, fig. .--t-head air-lock.] [illustration: plate lxiv, fig. .--cutting edge of caisson assembled.] [illustration: plate lxiv, fig. .--caisson supported on jacks and blocks.] concrete cradles, hand-packed stone and grouting. had the east avenue tunnel been built by shields, as was contemplated at the time of its design, the space between the limits of excavation and the iron lining would have been somewhat less than by the method actually used, especially in the earth portions. this space would have been filled with grout ejected through the iron lining. the change in the method of doing the work permitted the use of cheaper material, in place of part of the grout, and, at the same time, facilitated the work. the tube of cast-iron rings is adapted to be built in the tail of the shield. where no shield was used, after the excavation was completed and all loose rock was removed, timbers were fixed across the tunnel from which semicircular ribs were hung, below which lagging was placed. the space between this and the rough rock surface was filled with concrete. this formed a cradle in which the iron tube could be erected, and, at the same time, occupied space which would have been filled by grout, at greater cost, had a shield been used. as soon as each ring of iron was erected, the space between it and the roof of the excavation was filled with hand-packed stone. at about every sixth ring a wall of stone laid in mortar was built between the lining and the rock to serve as a dam to retain grout. the interstices between the hand-packed stones were then filled with to grout of cement and sand, ejected through the iron lining. the concrete cradles averaged . cu. yd. per ft. of tunnel, and cost, exclusive of materials, $ . per cu. yd., of which $ . was for labor and $ . was for top charges. the hand-packed stone averaged - / cu. yd. per ft. of tunnel, and cost $ . per cu. yd., of which $ . was for labor and $ . was for top charges. erection of iron lining. the contractors planned to erect the iron lining with erectors of the same pattern as that used on the shield under the river, mounted on a traveling stage. these will be described in detail in mr. japp's paper. two of these stages and erectors worked in each tunnel at different points. the tunnel was attacked from so many points that these erectors could not be moved from working to working. the result was that about % of the lining was built by hand. at first thought, this seems to be a crude and extravagant method, as the plates weighed about ton each and about , were erected by hand. as it turned out, the cost was not greater than for those erected by machinery, taking into account the cost of erectors and power. this, however, was largely because the hand erection reduced the amount of work to be done by the machines so much that the machines had an undue plant charge. the hand erection was very simple. a portable hand-winch, with a / -in. wire rope, was set in any convenient place. the wire rope was carried to a snatch-block fastened to the top of the iron previously built; or, where the roof was in soft ground, the timbering furnished points of attachment. the end of the wire rope was then hooked to a bolt hole in a new plate, two men at the winch lifted the plate, and three or four others swung it into approximate place, and, with the aid of bars and drift-pins, coaxed it into position and bolted it. where there was no timbering above the iron, sometimes the key and adjoining plates were set on blocking on a timber staging and then jacked up to place. long island shafts. the river shafts were designed to serve both as working shafts and as permanent openings to the tunnels, and were larger and more substantial than would have been required for construction purposes. plate x of mr. noble's paper shows their design. they consist of two steel caissons, each by ft. in plan, with walls ft. thick filled with concrete. a wall ft. thick separated each shaft into two wells by ft., each directly over a tunnel. circular openings for the tunnel, ft. in diameter, were provided in the sides of the caissons. during the sinking these were closed by bulkheads of steel plates backed by horizontal steel girders. the shafts were sunk as pneumatic caissons to a depth of ft. below mean high water. there have been a few caissons which were larger and were sunk deeper than these, but most large caissons have been for foundations, such as bridge piers, and have been stopped at or a little below the surface of the rock. the unusual feature of the caissons for the long island shaft is that they were sunk ft. through rock. it had been hoped that the rock would prove sound enough to permit stopping the caissons at or a little below the surface and continuing the excavation without sinking them further; for this reason only the steel for the lower ft. of the caissons was ordered at first. the roof of the working chamber was placed ft. above the cutting edge. it was a steel floor, designed by the contractors, and consisted of five steel girders, ft. deep, ft. long, and spaced at -ft. centers. between were plates curved upward to a radius of ft. each working chamber had two shafts, ft. by ft. in cross-section, with a diaphragm dividing it into two passages, the smaller for men and the larger for muck buckets. on top of these shafts were moran locks. mounted on top of the caisson was a -ton wilson crane, which would reach each shaft and also the muck cars standing on tracks on the ground level beside the caissons. circular steel buckets, ft. in. in diameter and ft. high, were used for handling all muck. these were taken from the bottom of the working chamber, dumped in cars, and returned to the bottom without unhooking. work was carried on by three -hour shifts per day. the earth excavation was done at the rate of about cu. yd. per day from one caisson. the rock excavation, amounting to about , cu. yd. in each caisson, was done at the rate of about . cu. yd. per day. the average rate of lowering, when the cutting edge of the south caisson was passing through earth, was . ft. per day. in rock, the rate was . ft. per day in the south caisson, and . ft. per day in the north caisson. at the beginning all lowering was done with sixteen hydraulic jacks. temporary brackets were fastened to the outside of the caisson. a -ton hydraulic jack was placed under each alternate bracket and under each of the others there was blocking. the jacks were connected to a high-pressure pump in the power-house. as the jacks lifted the caisson, the blocking was set for a lower position, to which the caisson settled as the jacks were exhausted. after the caisson had penetrated the earth about ft., the outside brackets were removed and the lowering was regulated by blocking placed under brackets in the working chamber. the caisson usually rested on three sets of blockings on each side and two on each end. the blocking was about ft. inside the cutting edge. in the rock, as the cutting edge was cleared for a lowering of about ft., by -in. oak posts were placed under the cutting-edge angle. when a sufficient number of posts had been placed, the blocking on which the caisson had rested was knocked or blasted out, and the rock underneath was excavated. the blocking was then re-set at a lower elevation. the posts under the cutting edge were then chopped part way through and the air pressure was lowered about lb., which increased the net weight to more than , , lb. the posts then gradually crushed and the caissons settled to the new blocking. the tilt or level of the caisson was controlled by chopping the posts more on the side which was desired to move first. the caisson nearly always carried a very large net weight, usually about tons. the concrete in the walls, which was added as the caisson was being sunk, was kept at about the elevation of the ground. there was generally a depth of from to ft. of water ballast on top of the roof of the working chamber. the air pressure in the working chamber was usually much less than the hydrostatic head outside the caisson. for example, the average air pressure in the south caisson during january, , was - / lb., while the average head was . ft., equivalent to lb. per sq. in. under these conditions, there was a continued but small leakage into the caisson of from , to , gal. per day. in the rock the excavation was always carried from to in. outside the cutting edge. as soon as the cutting edge was cleared, bags of clay were placed under it in a well-tiered, solid pile, so that when the caisson was lowered the bags were cut through and most of the clay, bags and all, was squeezed back of the cutting edge between the rock and the caisson. table shows the relation of the final position of the caissons to that designed. the cost of rock excavation in the caisson was $ . per cu. yd. for labor and $ . for top charges. the bottom of the shaft is an inverted concrete arch, ft. thick, water-proofed with -ply felt and pitch. as soon as the caisson was down to its final position and the excavation was completed, concrete was deposited on the uneven rock surfaces, brought up to the line of the water-proofing, and given a smooth -in. mortar coat. the felt was stuck together in -ply mats on the surface with hot coal-tar pitch. these were rolled and sent down into the working chamber, where they were put down with cold pitch liquid at ° fahr. each sheet of felt overlapped the one below in. the water-proofing was covered by a -in. mortar plaster coat, after which the concrete of the -ft. inverted arch was placed. while the water-proofing and concreting were being done, the air pressure was kept at from to lb. per sq. in., the full hydrostatic head at the cutting edge. after standing for ten days, the air pressure was taken off, and the removal of the roof of the working chamber was begun. the water-proofing was done by the union construction and waterproofing company. table .--relation of the final position of the caissons to that designed. ================================================================ location.| long island city. | ---------------------------------------------------------------- shaft. | north. | south. | ---------------------------------------------------------------- corner. | high. | east. | north. | high. | east. | north. | ---------------------------------------------------------------- northeast| . ft.| . ft.| . ft.| . ft.| . ft.| . ft.| northwest| . " | . " | . " | . " | . " | . " | southwest| . " | . " | . " | . " | . " | . " | southeast| . " | . " | . " | . " | . " | . " | ================================================================ ============================================================================= location.| manhattan. | ----------------------------------------------------------------------------- shaft. | north. | south. | ----------------------------------------------------------------------------- corner. | high. | east. | south. | high. | east or west.|north or south.| ----------------------------------------------------------------------------- northeast| . ft.| . ft.| . ft.| . ft.| . ft. east.| . ft. south.| northwest| . " | . " | . " | . " | . " " | . " north.| southwest| . " | . " | . " | . " | . " west.| . " " | southeast| . " | . " | . " | . " | . " " | . " south.| ============================================================================= the cost of labor in compressed air chargeable to concreting was $ . per cu. yd. after the roof of each working chamber had been removed, the shield was erected on a timber cradle in the bottom of the shaft, in position to be shoved out of the opening in the west side of the caisson. temporary rings of iron lining were erected across the shaft in order to furnish something for the shield jacks to shove against. the roof of the working chamber was then re-erected about ft. above its original position and about ft. above the tunnel openings. this time, instead of the two small shafts which were in use during the sinking of the caisson, a large steel shaft with a t-head lock was built. this is illustrated in fig. , plate lxiv. the shaft was ft. in diameter. inside there was a ladder and an elevator cage for lowering and hoisting men and the standard -yd. tunnel cars. at the top, forming the head of the t, there were two standard tunnel locks. manhattan shafts. a permanent shaft, similar to the river shafts in long island city, was constructed at manhattan over each pair of tunnels. each shaft was located across two lines, with its longer axis transverse to the tunnels. plate xiii shows their relative positions. they were divided equally by a reinforced concrete partition wall transverse to the line of the tunnels. on completion, the western portions were turned over to the contractor for the cross-town tunnels for his exclusive use. _south shaft._--work on the south shaft was started on june th, , with the sinking of a by -ft. test pit in the center of the south half of the south shaft, which reached disintegrated rock at a depth of about ft. starting in august, the full shaft area, by ft., was taken out in an open untimbered cut to the rock, and a by -ft. shaft was sunk through the rock to tunnel grade, leaving a or -ft. berm around it. (fig. , plate lxx.) the erection of the caisson was started, about the middle of january, on the rock berm surrounding the by -ft. shaft and about ft. below the surface. fig. , plate lxiv, shows the cutting edge of the caisson assembled. the excavation of the small shaft had shown that hard rock and only a very small quantity of water would be encountered, and that the caisson need be sunk only a short distance below the rock surface. therefore, no working-chamber roof was provided, the caisson was built to a height of only ft., and the circular openings were permanently closed. the assembling of the caisson took - / months, and on april d lowering was started. inverted brackets were bolted temporarily to the cutting-edge stiffening brackets, and the sinking was carried on by methods similar to those used at long island. the jacks and blocking supporting the caisson are shown in fig. , plate lxiv. as soon as the cutting edge entered the rock, which was drilled about in. outside of the neat lines, the space surrounding the caisson was back-filled with clay and muck to steady it and provide skin friction. as the friction increased, the walls were filled with concrete, and as the caisson slowly settled, it was checked and guided by blocking. the cutting edge finally came to rest ft. below mean high water, the sinking having been accomplished in about seven weeks, at an average rate of . ft. per day. the final position of the cutting edge in relation to its designed position is shown in table . a berm about ft. wide was left at the foot of the caisson below which the rock was somewhat fissured and required timbering. the cutting edge of the caisson was sealed to the rock with grout on the outside and a concrete base to the caisson walls on the inside, the latter resting on the -ft. berm. following the completion of the shaft, the permanent sump was excavated to grade for use during construction. _north shaft._--the north shaft had to be sunk in a very restricted area. the east side of the caisson cleared an adjoining building at one point by only ft., while the northwest corner was within the same distance of the east line of first avenue. as in the case of the long island shafts, the steelwork for only the lower ft. was ordered at the start. this height was completely assembled before sinking was begun. the caisson was lowered in about the same manner as those previously described. the bearing brackets for the hydraulic jacks were attached, as at the south shaft, to the inside of the cutting-edge brackets. the east side of the caisson was in contact with the foundations of the neighboring building, while the west side was in much softer material. as a consequence, the west side tended to settle more rapidly and thus throw the caisson out of level and position. to counteract that tendency, it was necessary to load the east wall heavily with cast-iron tunnel sections, in addition to the concrete filling in the walls. soon after sinking was begun, a small test shaft was sunk to a point below the elevation of the top of the tunnels. the rock was found to be sound, hard, and nearly dry. it was then decided to stop the caisson as soon as a foundation could be secured on sound rock. the latter was found at a depth of ft. below mean high water. with the cutting edge seated at that depth, the top of the caisson was only ft. above mean high water, and as this was insufficient protection against high tides, a -ft. extension was ordered for the top. work, however, went on without delay on the remainder of the excavation. the junction between the cutting edge and the rock was sealed with concrete and grout. the caisson was lowered at an average rate of . ft. per day. the size of the shaft below the cutting edge was ft. in. by ft. the average rate of excavation during the sinking in soft material was cu. yd. per day. the average rate of rock excavation below the final position of the cutting edge was cu. yd. per day. there were night and day shifts, each working hours. excavation in earth cost $ . per cu. yd., of which $ . was for labor and $ . for top charges, etc. the excavation of rock cost $ . per cu. yd., $ . being for labor and $ . for top charges. the final elevations of the four corners of the cutting edge, together with their displacement from the desired positions, are shown in table . river tunnels. the four river tunnels, between the manhattan and long island city shafts, a distance of about , ft., were constructed by the shield method. eight shields were erected, one on each line in each shaft, the four from manhattan working eastward to a junction near the middle of the river with the four working westward from long island city. toward the end of the work it was evident that the shields in tunnels _b_, _c_, and _d_ would meet in the soft material a short distance east of the blackwell's island reef if work were continued in all headings. in order that the junction might be made in firm material, work from manhattan in those three tunnels was suspended when the shields reached the edge of the ledge. the shields in tunnel _a_ met at a corresponding point without the suspension of work in either. an average of , ft. of tunnel was driven from manhattan and , ft. from long island city. [illustration: plate lxv, fig. .--shield fitted with sectional sliding hoods and sliding extensions to the floors.] [illustration: plate lxv, fig. .--shield fitted with fixed hoods and fixed extensions to the floors.] tunnels driven eastward from manhattan. _materials and inception of work._--the materials encountered are shown in the profile on plate xiii, and were similar in all the tunnels. in general, they were found to be about as indicated in the preliminary borings. the materials met in tunnel _a_ may be taken as typical of all. from the manhattan shaft eastward, in succession, there were ft. of all-rock section, ft. of part earth and part rock, ft. of all earth, ft. of part rock and part earth, ft. of all rock, and ft. of part rock and part earth. the rock on the manhattan side was hudson schist, while that in the reef was fordham gneiss. here, as elsewhere, they resembled each other closely; the gneiss was slightly the harder, but both were badly seamed and fissured. wherever it was encountered in this work, the rock surface was covered by a deposit of boulders, gravel, and sand, varying in thickness from to ft. and averaging about ft. the slope of the surface of the ledge on the manhattan side averaged about vertical to horizontal. the rock near the surface was full of disintegrated seams, and was badly broken up. it was irregularly stratified, and dipped toward the west at an angle of about degrees. large pieces frequently broke from the face and slid into the shield, often exposing the sand. the rock surface was very irregular, and was covered with boulders and detached masses of rock embedded in coarse sand and gravel. the sand and gravel allowed the air to escape freely. by the time the shields had entirely cleared the rock, the material in the face had changed to a fine sand, stratified every few inches by very thin layers of chocolate-colored clayey material. this is the material elsewhere referred to as quicksand. as the shield advanced eastward, the number and thickness of the layers of clay increased until the clay formed at least % of the entire mass, and many of the layers were in. thick. at a distance of about ft. beyond the manhattan ledge, the material at the bottom of the face changed suddenly to one in which the layers of clay composed probably % of the whole. the sand layers were not more than / in. thick and averaged about in. apart. the surface of the clay rose gradually for a distance of ft. in tunnels _a_ and _b_, and ft. in tunnels _c_ and _d_, when gravel and boulders appeared at the bottom of the shield. at that time the clay composed about one-half of the face. the surfaces of both the clay and gravel were irregular, but they rose gradually. after rock was encountered, the formations of gravel and clay were roughly parallel to the rock surface. as the surface of the rock rose they disappeared in order and were again encountered when the shields broke out of rock on the east side of the blackwell's island reef. east of the reef a large quantity of coarse open sand was present in the gravel formations before the clay appeared below the top of the cutting edge. in tunnels _c_ and _d_ this was especially difficult to handle. it appears to be a reasonable assumption that the layer of clay was continuous across the reef. wherever the clay extended above the top of the shield it reduced the escape of air materially. it is doubtless largely due to this circumstance that the part-rock sections in the reef were not the most difficult portions of the work. while sinking the lower portions of the shafts the tunnels were excavated eastward in the solid rock for a distance of about ft., where the rock at the top was found to be somewhat disintegrated. this was as far as it was considered prudent to go with the full-sized section without air pressure. at about the same time top headings were excavated westward from the shafts for a distance of ft., and the headings were enlarged to full size for ft. the object was to avoid damage to the shaft and interference with the river tunnel when work was started by the contractor for the cross-town tunnel. [illustration: plate lxvi, fig. .--rear of shield showing complete fittings.] [illustration: plate lxvi, fig. .--shield with lower portion of bulkhead removed.] the shields were erected on timber cradles in the shaft, and were shoved forward to the face of the excavation. concrete bulkheads, with the necessary air-locks, were then built across the tunnels behind the shields. the shields were erected before the dividing walls between the two contracts were placed. rings of iron tunnel lining, backed by timbers spanning the openings on the west side, were erected temporarily across the shafts in order to afford a bearing for the shield jacks while shoving into the portals. the movement of the shield eastward was continued in each tunnel for a distance of about ft., and the permanent cast-iron tunnel lining was erected as the shield advanced. before breaking out of rock, it was necessary to have air pressure in the tunnels. this required the building of bulkheads with air-locks inside the cast-iron linings just east of the portals. before erecting the bulkheads it was necessary to close the annular space between the iron tunnel lining and the rock. the space at the portal was filled with a concrete wall. after about twenty permanent rings had been erected in each tunnel, two rings were pulled apart at the tail of the shield and a second masonry wall or dam was built. the space between the two dams was then filled with grout. to avoid the possibility of pushing the iron backward after the air pressure was on, rings of segmental plates, / in. thick and - / in. wide, were inserted in eighteen circumferential joints in each tunnel between the rings as they were erected. the plates contained slotted holes to match those in the segments. after the rings left the shield, the plates were driven outward, and projected about in. when the tunnel was grouted, the plates were embedded. the bulkheads were completed, and the tunnels were put under air pressure on the following dates: line _d_, on october th, ; line _c_, on november th, ; line _b_, on november th, ; line _a_, on december st, . this marked the end of the preparatory period. in the deepest part of the river, near the pier-head line on the manhattan side, there was only ft. of natural cover over the tops of the tunnels. this cover consisted of the fine sand previously described, and it was certain that the air would escape freely from the tunnels through it. to give a greater depth of cover and to check the loss of air, the contractor prepared to cover the lines of the tunnels with blankets of clay, which, however, had been provided for in the specifications. permits, as described later, were obtained at different times from the secretary of war, for dumping clay in varying thicknesses over the line of work. the dumping for the blanket allowed under the first permit was completed in february, . the thickness of this blanket varied considerably, but averaged or ft. on the manhattan side. the original blanket was of material advantage, but the depth of clay was insufficient to stop the loss of air. the essential parts of the shields in the four tunnels were exactly alike. those in tunnels _b_ and _d_, however, were originally fitted with sectional sliding hoods and sliding extensions to the floors of the working chambers, as shown by fig. , plate lxv. the shields in tunnels _a_ and _c_ were originally fitted with fixed hoods and fixed extensions to the floors, as shown in fig. , plate lxv. a full description of the shields will be found in mr. japp's paper. the shields in each pair of tunnels were advanced through the solid rock section about abreast of each other, until test holes from the faces indicated soft ground within a few feet. as the distance between the sides of the two tunnels was only ft., it was thought best to let tunnels _b_ and _d_ gain a lead of about ft. before tunnels _a_ and _c_ opened out into soft ground, in order that a blow from one tunnel might not extend to the other. work in tunnel _c_ was shut down on december d, , after exposing sand to a depth of ft. at the top, and it remained closed for seven weeks. work in tunnel _a_ was suspended on september th, . by the time tunnel _b_ had made the required advance, it, together with tunnels _c_ and _d_, was overtaxing the capacities of the compressor plant. only a little work was done in tunnel _c_ until july, , and work in tunnel _a_ was not resumed until october d, . tunnels driven westward from long island city. _materials and inception of the work._--the materials met in tunnel a are typical of all four tunnels. from the long island shafts westward, in succession, there were ft. of all-rock section, ft. of part rock and part earth section, ft. of all-rock section, ft. of part rock and part earth section, ft. of all-rock section, ft. of part earth and part rock section, and , ft. of all-earth section. [illustration: plate lxvii] the materials passed through are indicated on plate xiii. the rock was similar to that of the blackwell's island reef, and was likewise covered by a layer of sand and boulders. the remainder of the soft ground was divided into three classes. the first was a very fine red sand, which occurred in a layer varying in thickness from ft. to at least ft. it may have been much deeper above the tunnel. it is the quicksand usually encountered in all deep foundations in new york city. the following is the result of the sifting test of this sand: held on no. sieve . % passed no. , " " no. " . % " no. , " " no. " . % " no. , " " no. " . % " no. , " " no. " . % " no. , " " no. " . % " no. , " " no. " . % " no. " . % ------ . % this means that grains of all but % of it were less than . in. in diameter. the % which passed the no. sieve, the grains of which were . in. or less in diameter, when observed with a microscope appeared to be perfectly clean grains of quartz; to the eye it looked like ordinary building sand, sharp, and well graded from large to small grains. this sand, with a surplus of water, was quick. with the water blown out of it by air pressure, it is stable, stands up well, and is very easy to work. it appears to be the same as the reddish quicksand found in most deep excavations around new york city. the second material was pronounced "bull's liver" by the miners as soon as it was uncovered. "bull's liver" seems to be a common term among english-speaking miners the world over. it is doubtful, however, if it is always applied to the same thing. in this case it consisted of layers of blue clay and very fine red sand. the clay seemed to be perfectly pure and entirely free from sand. it would break easily with a clean, almost crystalline, fracture, and yet it was soft and would work up easily. the layers of clay varied in thickness from / in. to in., while the thickness of the sand layer varied from / in. to several inches. the sand was the same as the quicksand already described. the "bull's liver" was ideal material in which to work a shield. it stood up as well and held the air about as well as clay, and was much easier to handle. the third material was a layer of fine gray sand which was encountered in the top of all the tunnels for about ft. just east of blackwell's island reef. it was very open, and had grains of rather uniform size. during the starting out of the tunnels from the shafts, and for more than a year afterward, the roof of the working chamber in the caissons and the locks previously described under the long island shafts took the place of the bulkhead across the tunnels for confining the air pressure. the first work in air pressure was to remove the shield plug closing the opening in the side of the shaft. this being done, the shield was shoved through the opening, and excavation begun. at the start the shields were fitted with movable platforms, but no hoods of any kind were placed until after the rock excavation was completed. methods of excavation. the distribution of materials to be excavated, as previously outlined, divided the excavation into three distinct classes, for which different methods had to be developed. these three classes were: _first._--all-rock section. _second._--rock in the bottom, earth in the top. _third._--all-earth section. the extent of the second and third classes was much greater than that of the first, and they, of course, determined the use of the shield. shields had not previously been used extensively in rock work, either where the face was wholly or partly in rock, and it was necessary to develop the methods by experience. the specifications required that where rock was present in the bottom, a bed of concrete should be laid in the form of a cradle on which to advance the shield. _all rock._--at different times, three general methods were used for excavating in all-rock sections. they may be called: the bottom-heading method; the full-face method; and the center-heading method. the bottom-heading method was first tried. a heading, about ft. high and ft. wide, was driven on the center line, with its bottom as nearly as possible on the grade line of the bottom of the tunnel. it was drilled in the ordinary manner by four drills mounted on two columns. the face of the headings varied from to ft. in advance of the cutting edge. after driving the heading for about ft., the bottom was cleared out and a concrete cradle was set. the width of the cradles varied, but was generally from to ft. the excavation was enlarged to full size as the shield advanced, the drills being mounted in the forward compartments of the shield, as shown by fig. , plate lxvii, which represents the conditions after the opening had been cut in the bulkhead, but before the new methods, mentioned later, had been developed. [illustration: plate lxviii] the sides and top were shot downward into the heading. the area of the face remaining behind the heading was large, and a great number of holes and several rounds were required to fire the face to advantage. as soon as firing was started at the face, the heading was completely blocked, and operations there had to be suspended until the mucking was nearly completed. the bottom-heading method was probably as good as any that could be devised for use with the shields as originally installed. all the muck had to be taken from the face by hand and handled through the chutes or doors. by drilling from the shield, some muck was blasted on to the extensions of the floors and could be handled from the upper compartments. at best, however, the shield with the closed transverse bulkhead was a serious obstacle to rapid work in rock sections. the full-face method was only used where the rock was not considered safe for a heading. a cut was fired at the bottom, together with side holes, in a manner quite similar to that adopted in the first set of holes for a bottom heading. the cradle was then placed, in lengths of either . or ft., after which the remainder of the face was fired in the same manner as for the bottom-heading method. the closed transverse bulkhead with air-locks, as shown in fig. , plate lxvi, was placed in the shield in the hope that it would only be necessary to maintain the full air pressure in the working compartments in front of the bulkhead. it was also thought that some form of bulkhead which could be closed quickly and tightly would be necessary to prevent flooding the tunnel in case of blows. while no attempt was ever made to reduce the pressure behind the shield bulkhead, it was obvious from the experience with tunnels _b_ and _d,_ while working in the sand between manhattan and the reef, that the plan was not practicable, and that the closed bulkhead in the bottom was a hindrance instead of a safeguard. as soon as rock was encountered in those tunnels at the west edge of the reef, the contractor cut through the bulkheads and altered them, as shown in fig. , plate lxvi. taking advantage of the experience gained, openings were cut through the bulkheads in shields _a_ and _c_, while they were shut down near the edge of the manhattan ledge. in erecting the shields at long island city in may and june, , openings were also provided. these shields had to pass through about ft. of rock at the start, the greater portion of which was all-rock section. it was at that point that openings were first used extensively and methods were developed, which would not have been possible except where ears could be passed through the shield. the bottom-heading method was first tried, but the working space in front of the shield was cramped, and but few men could be employed in loading the cars. to give more room, the heading was gradually widened. the enlargement at the top, when made from the shield, blocked all work at the face of the heading while the former operation was in progress. to reduce the delays, the heading was raised, thus reducing the quantity of rock left in the top, and the bottom was taken out as a bench. to avoid blocking the tracks when firing the top, a heavy timber platform was built out from the floors of the middle working compartments. most of the muck from the top was caught on the platform and dropped into cars below. this method of working is shown by fig. , plate lxvii. the platforms were not entirely satisfactory, and, later, the drills in the heading were turned upward and a top bench was also drilled and fired, as shown by fig. , plate lxvii. there was then so little excavation left in the top that the muck was allowed to fall on the tracks and was quickly cleared away. the method just outlined is called the center-heading method, and was the most satisfactory plan devised for full-rock sections. _excavation in part rock and part earth._--this was probably the most difficult work encountered, particularly when the rock was covered with boulders and coarse sharp sand which permitted a free escape of air. it was necessary, before removing the rock immediately under the soft ground, to excavate the earth in advance of the shield to a point beyond where the rock was to be disturbed, and to support, in some way, the roof, sides, and face of the opening thus made. the hoods were designed mainly for the purpose of supporting the roof and the sides. with the fixed hood it was necessary either to excavate for the distance of the desired shove in front of it or else to force the hood into the undisturbed material. to avoid this difficulty, the sliding hoods were tried as an experiment. in using the sliding hood, which will be described in detail in mr. japp's paper, the segments commencing at the top were forced forward by the screw rod, one at a time, as far as possible into the undisturbed material. just enough material was then removed from underneath and in front of the section to free it, and it was again forced forward. these operations were repeated until the section had been extended far enough for a shove. as soon as two or three sections had been pushed forward in this way, the face near the advance end of the sliding hood was protected by a breast board set on edge and braced from the face. gradually, all the segments were worked forward, and, at the same time, the whole soft ground face was sheeted with timber. at times polings were placed over the extended segments in order to make room for a second shove, as shown on plate lxviii. when the shield was advanced the nuts on the screw rods were loosened and the sections of the hoods were telescoped on to the shield. the idea was ingenious, but proved impracticable, because of the unequal relative movements of the top and bottom of the shield in shoving, bringing transverse strains on the hood sections. [illustration: plate lxix] with the fixed hood, poling boards were used to support the roof and sides, and the face was supported in the manner described for the sliding hoods. the polings were usually maple or oak planks, in. thick, about in. wide, and - / ft. long. in advancing the face, the top board of the old breast was first removed, then the material was carefully worked out for the length of the poling. the latter was then placed, with the rear end resting over the hood and the forward end forced as far as possible into the undisturbed material. when two or three polings had been placed, a breast board was set. after several polings were in position, their forward ends were supported by some form a cantilever attached to the hood. plate lxix shows one kind of supports. in this way all the soft material was excavated down to the rock surface, and the roof, sides, and face were sheeted with timber. in shoving, the polings in the roof and sides were lost. it was found that the breast could usually be advanced ft. with safety. the fixed hood made it possible to set the face about or ft. in front of the cutting edge without increasing the length of the polings. this distance was ample for two shoves, and was generally adopted, although a great many faces were set for one shove only. fixed hoods were substituted for those of the sliding type, originally placed on shields _b_ and _d_ at manhattan, at about the time the latter encountered the rock at the reef. in placing the polings and breasting, all voids behind them were filled as far as possible with marsh hay or bags of sawdust or clay. to prevent loss of air in open material, the joints between the boards were plastered with clay especially prepared for the purpose in a pug mill. the sliding extensions to the floors of the working compartments were often used, in the early part of the work, to support the timber face or loose rock, as shown in fig. , plate lxviii. at such times the front of the extensions was held tightly against the planking by the pressure of the floor jacks. while shoving, the pressure on the floor jacks was gradually released, allowing the floors to slide back into the shield and still afford support to the face. the extensions also afforded convenient working platforms. they were subject to severe bending strains while the shield was being shoved, however, and the cast-iron rams were frequently broken or jammed. the extensions did not last beyond the edge of the ledge at manhattan, nor more than about half through the rock work at long island city. the fixed extensions originally placed on shields _a_ and _c_ at manhattan were not substantial enough, and lasted only a few days. wherever the rock face was sufficiently sound and high, a bottom heading was driven some or ft. in advance of the shield. the heading was driven and the cradle placed independently of the face of the soft ground above, and in the manner described for all-rock sections. the remainder of the rock face was removed by firing top and side rounds into the bottom heading after the soft ground had been excavated. great care had to be taken in firing in order not to disturb the timber work or break the rock away from under the breast boards. if either occurred, a serious run was likely to follow. the bottom-heading method is shown by figs. , , and , plate lxviii, and the breasting and poling by fig. , plate lxx. in the early part of the work, where a bottom heading was impracticable, the soft ground was first excavated as described above, and the rock was drilled by machines mounted on tripods, and fired as a bench. by this plan no drilling could be done until the soft ground was removed. this is called the rock-bench method. later the rock-cut method was devised. drills were set up on columns in the bottom compartments of the shield, and the face was drilled while work was in progress on the soft ground above. the drilling was done either for a horizontal or vertical cut and side and top rounds. the drillers were protected while at work by platforms of timber built out from the floors of the compartments above. this plan, while probably not quite as economical of explosives, saved nearly all the delay due to drilling the bench. [illustration: plate lxx, fig. .--small shaft sunk to rock.] [illustration: plate lxx, fig. .--breasting and poling in front of shield.] [illustration: plate lxx, fig. .--shutters on front of shield.] [illustration: plate lxx, fig. .--hydraulic erector placing segment.] _all-earth section._--as described by messrs. hay and fitzmaurice, in a paper on the blackwall tunnel,[c] the contractor had used, with marked success, shutters in the face of the shield for excavating in loose open material. he naturally adopted the method for the east river work. when the shields in tunnels _b_ and _d_, at manhattan, the first to be driven through soft ground, reached a point under the actual bulkhead line, work was partly suspended and shutters were put in place in the face of the top and center compartments. the shutters in the center compartments in shield _d_ are shown in fig. , plate lxx, while the method of work with the shutters is shown by figs. , , , and , plate lxviii. fig. on that plate shows the shield ready for a shove. as the pressure was applied to the shield jacks, men loosened the nuts on the screws holding the ends of the shutters, and allowed the latter to slide back into the working compartments. at the end of the shove, the shutters were in the position shown in fig. , plate lxviii. in preparing for a new shove, the slides in the shutters were opened, and the material in front was raked into the shield. at the same time, the shutters were gradually worked forward. the two upper shutters in a compartment were generally advanced from to in., after which the muck could be shoveled out over the bottom shutters, as shown on fig. , plate lxviii, and fig. , plate lxx. no shutters were placed in the bottom compartments, and as the air pressure was not generally high enough to keep the face dry at the bottom, these compartments were pretty well filled with the soft, wet quicksand. just before shoving, this material was excavated to a point where it ran in faster than it could be taken out. much of the excavation in the bottom compartment was done by the blow-pipe. during the shove the material from the bottom compartment often ran back through the open door in the transverse bulkhead, as shown by fig. , plate lxviii. in the blackwall tunnel the material was reported to have been loose enough to keep in close contact with the shutters at all times. in the east river tunnels this was not the case. the sand at the top was dry and would often stand with a vertical face for some hours. in advancing the shutters, it was difficult to bring them into close contact with the face at the end of the operation. the soft material at the bottom was constantly running into the lower compartment and undermining the stiff dry material at the top. the latter gradually broke away, and, at times, the actual face was some feet in advance of the shutters. under those circumstances, the air escaped freely through the unprotected sand face. the joints of the shutters were plastered with clay, but this did not keep the air from passing out through the lower compartments. this condition facilitated the formation of blows, which were of constant occurrence where shutters were used in the sand. in tunnels _b_ and _d_, at manhattan, the shutters were used in the above manner clear across to the reef. in tunnel _c_, which was considerably behind tunnels _b_ and _d_, the shutters, although placed, were never used against the face, and the excavation was carried on by poling the top and breasting the face. the change resulted in much better progress and fewer blows. the excavation through the soft material in tunnel _c_ had just been completed when tunnel _a_ was started, and the gangs of workmen were exchanged. the work in soft ground in tunnel _a_ thus gained the benefit of the experience in tunnel _c_. shutters were placed only in the top compartments in this tunnel, and, as in tunnel _c_, were never used in contact with the face. the method of work is shown by figs. , , and , plate lxxi. the result was still more rapid progress in tunnel _a_, and although the loss of air was fully as great in this tunnel as in the other three, there was only one blow which caused any considerable loss of pressure. in tunnels _a_ and _c_ the diaphragms in the rear of the center compartments of the lower tiers of working chambers were removed before the shields entered the soft ground. the change was not of as much advantage in soft ground as in rock, but it facilitated the removal of the soft wet sand in the bottom. in tunnel _a_, after encountering gravel, a belt conveyor was suspended from the traveling stage with one end projecting through the opening into the working compartment. the use of the conveyor made it possible to continue mucking at the face while the bottom plates of the iron lining were being put in place, and resulted in a material increase in the rate of progress. [illustration: plate lxxi] the shutters were not placed on the long island shields at all. just before the shields passed into all soft ground, a fixed hood was attached to each. the method of working in soft ground from long island city is illustrated by plate lxxii. the full lines at the face of the shield show the position of the earth before a shove of the shield, and the dotted lines show the same after the shove. the face was mined out to the front of the hood and breasted down to a little below the floor of the top pockets of the shield. in the middle pocket the earth was allowed to take its natural slope back on the floor. toward the rear of the bottom pockets it was held by stop-planks. the air pressure was always about equal to the hydrostatic head at the middle of the shield, so that the face in the upper and middle pockets was dry. in the lower pockets it was wet, and flowed under the pressure of shoving the shield. by this method , lin. ft. of tunnel was excavated by the four long island shields in days, from november st, , to march st, . this was an average of . ft. per day per shield. the rate of progress, the nature of the materials, and the methods adopted are shown in table . _preparations for junction of shields._--as previously mentioned, the manhattan shields were stopped at the edge of the reef. before making the final shove of those shields, special polings were placed with unusual care. the excavation was bell-shaped to receive the long island shields. the arrangement of the polings is shown by figs. and , plate lxxi. after the shields were shoved into final position, as shown at the right in fig. , the rear end of the polings rested over the cutting edge and allowed room for the removal of the hood. after the latter had been accomplished, the temporary bulkheads of concrete and clay bags were built as a precaution against blows when the shields were close together. an -in. pipe was then driven forward through the bulkhead for distances varying from to ft., in order to check the alignment and grade between the two workings before the shields were actually shoved together. the errors in the surveys were negligible, but here, as elsewhere, the shields were not exactly in the desired position, and it took careful handling to bring the cutting edges together. the long island shields were driven to meet those from manhattan. table .--rate of progress, nature of materials, and methods adopted in construction of east river tunnels. line a, long island. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ all rock |bottom heading | + . | + |aug. , ' |sept , ' | | | | | | | all rock |center heading | + | + |sept , ' |nov. , ' | | | | | | | earth and rock|center heading | + | + |nov. , ' |dec. , ' | | | | | | | earth and rock|bottom heading | + | + |dec. , ' |feb. , ' | | | | | | | all rock |bottom heading | + | + |feb. , ' |feb. , ' | | | | | | | earth and rock|center heading | + | + |feb. , ' |mar. , ' | | | | | | | all rock |center heading | + | + |mar. , ' |sept , ' | | | | | | | earth and rock|going out of rock| + | + |sept , ' |oct. , ' | | | | | | | all earth |soft ground | + | + . |oct. , ' |mar. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ all rock | | . | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | earth and rock| | | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | all earth | | , . | . | | --------------+------+--------+--------+--------------------------------------+ line b, long island. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ all rock |bottom heading | + . | + |oct. , ' |nov. , ' | | | | | | | earth and rock|bottom heading | + | + |nov. , ' |feb. , ' | | | | | | | all rock |bottom heading | + | + |feb. , ' |mar. , ' | | | | | | | earth and rock|center heading | + | + |mar. , ' |mar. , ' | | | | | | | all rock |going out of rock| + | + |mar. , ' |aug. , ' | | | | | | | earth and rock|soft ground | + | + |aug. , ' |sept , ' | | | | | | | all earth |soft ground | + | + . |sept , ' |mar. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ all rock | | . | . | | | | | | | earth and rock| | | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | all earth | | , . | . | | --------------+------+--------+--------+--------------------------------------+ line c, long island. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ all rock |bottom heading | + . | + |june , ' |oct. , ' | | | | | | | earth and rock|bottom heading | + | + |oct. , ' |feb. , ' | | | | | | | all rock |bottom heading | + | + |feb. , ' |feb. , ' | | | | | | | all rock |center heading | + | + |feb. , ' |july , ' | | | | | | | earth and rock|going out of rock| + | + |july , ' |aug. , ' | | | | | | | all earth |soft ground | + | + . |aug. , ' |mar. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ all rock | | . | . | | | | | | | earth and rock| | | . | | | | | | | all rock | | | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | all earth | | , . | . | | --------------+------+--------+--------+--------------------------------------+ line d, long island. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ rock |bottom heading | + . | + |june , ' |oct. , ' | | | | | | | earth and rock|bottom heading | + | + |oct. , ' |jan. , ' | | | | | | | all rock |bottom heading | + | + |jan. , ' |mar. , ' | | | | | | | all rock |center heading | + | + |mar. , ' |july , ' | | | | | | | earth and rock|going out of rock| + | + |july , ' |sept , ' | | | | | | | all earth |soft ground | + | + . |sept , ' |mar. . ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ rock | | . | . | | | | | | | earth and rock| | | . | | | | | | | all rock | | | . | | | | | | | all rock | | | . | | | | | | | earth and rock| | | . | | | | | | | all earth | | , . | . | | --------------+------+--------+--------+--------------------------------------+ line a, manhattan. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ {|top heading | + | + |july , ' |aug. , ' | rock {|top lift of bench| + | + |aug. , ' |aug. , ' | {|bottom lift of | + | + |aug. , ' |sept , ' | {| bench | | | | | | | | | | | rock {|bottom heading | + | + |sept , ' |oct. , ' | {|bottom heading | + | + |nov. , ' |dec. , ' | | | | | | | mixed |bottom heading | + | + |oct. , ' |nov. , ' | | | | | | | mixed |rock bench | + | + |nov. , ' |jan. , ' | | | | | | | earth |poling and | + | + |jan. , ' |apr. , ' | | breasting | | | | | | | | | | | mixed |rock cut | + | + |apr. , ' |oct. , ' | | | | | | | rock |bottom heading | + | + |oct. , ' |nov. , ' | | | | | | | rock |center heading | + | + |nov. , ' |dec. , ' | | | | | | | rock |bottom heading | + | + |dec. , ' |feb. , ' | | | | | | | mixed |rock cut | + | + |feb. , ' |mar. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ {| } | | {|excavation in normal air, and before | rock {| } | | . {|advance of shield. | {| } | | {| | {| | | {| | | | | | | rock {| } | | . {|bottom heading timbered to avoid the | {| } | | {|possibility of a break. | | | | | | mixed | | | . |bottom heading timbered. | | | | | | mixed | | | . | | | | | | | earth | | | . | | | | | | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | rock | | | . | | | | | | | rock | | | . | | | | | | | mixed | | | . | | --------------+------+--------+--------+--------------------------------------+ line b, manhattan. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ {|top heading | + | + |july , ' |july , ' | {|top lift of bench| + | + |aug. , ' |aug. , ' | rock {|bottom lift of | | | | | {| bench | + | + |aug. , ' |aug. , ' | {|bottom lift of | | | | | {| bench | + | + |sept , ' |sept , ' | | | | | | | rock |bottom heading | + | + |oct. , ' |jan. , ' | | | | | | | mixed |bottom heading | + | + |jan. , ' |feb. , ' | | | | | | | mixed |rock bench | + | + |feb. , ' |mar. , ' | | | | | | | earth |poling and | + | + |mar. , ' |apr. , ' | | breasting | | | | | | | | | | | |shutters in | | | | | earth | contact with | + | + |apr. , ' |nov. , ' | | face | | | | | | | | | | | mixed |rock bench | + | + |nov. . ' |dec. , ' | | | | | | | mixed |bottom heading | + | + |dec, , ' |feb. , ' | | | | | | | mixed |rock cut | + | + |feb. , ' |aug. , ' | | | | | | | rock |full face | + | + |aug. , ' |sept , ' | | | | | | | rock |center heading | + | + |sept , ' |oct. , ' | | | | | | | rock |bottom heading | + | + |oct. , ' |dec. , ' | | | | | | | mixed |rock cut | + | + . |dec. , ' |jan. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ {| } | | {| | {| } | | {| | rock {| } | | . {|excavation done in normal air and | {| } | | {|before advance of shield. | {| } | | {| | {| } | | {| | | | | | | rock | | | . | | | | | | | mixed | | | . | | | | | | | mixed | | | . | | | | | | | earth | | | | | | | | . | | | | | | | | | | | | earth | | | . | | | | | | | | | | | | mixed | | | . | | | | | | | mixed | | | . | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | rock | | | . | | | | | | | rock | | | . | | | | | | | mixed | | . | . | | --------------+------+--------+--------+--------------------------------------+ line c, manhattan. --------------+-----------------+-------------------+-------------------------+ | | station: | date: | | |---------+---------+------------+------------+ | | | | | | material. | method. | from | to | from | to | --------------+-----------------+---------+---------+------------+------------+ {|top heading | + . | + |dec. , ' |dec. , ' | {|top heading | + | + |jan. , ' |jan. , ' | rock {|excavating bench | + | + |jan. , ' |feb. , ' | {|bottom heading | + | + |mar. , ' |mar. , ' | {|bottom heading | + | + |oct. , ' |oct. , ' | {| | | | | | | | | | | | rock |bottom heading | + | + |nov. , ' |dec. , ' | | | | | | | | | | | | | mixed |bottom heading | + | + |dec. , ' |dec. , ' | | | | | | | | | | | | | mixed |bottom heading | + | + |feb. , ' |mar. , ' | | | | | | | mixed |rock cut | + | + |apr. , ' |apr. , ' | | | | | | | mixed |rock cut | + | + |july , ' |aug. , ' | | | | | | | | | | | | | earth |breasting and | + | + |aug. , ' |jan. , ' | | poling | | | | | | | | | | | mixed |rock cut | + | + |jan. , ' |feb. , ' | | | | | | | rock |full face | + | + |feb. , ' |feb. , ' | | | | | | | mixed |bottom heading | + | + |feb. , ' |mar. , ' | | | | | | | rock |bottom heading | + | + |mar. , ' |mar. , ' | | | | | | | mixed |rock cut | + | + |mar. , ' |july , ' | | | | | | | rock |middle heading | + | + |july , ' |aug. , ' | | | | | | | mixed |rock cut | + | + |aug. , ' |oct. , ' | | | | | | | rock |middle heading | + | + |oct. , ' |nov. , ' | | | | | | | mixed |rock cut | + | + |nov. , ' |feb. , ' | | | | | | | mixed |rock cut | + | + . |feb. , ' |mar. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ {| } | | {|stopped to brace portal. no work done | {| } | | {|from march th to october th, ,| rock {| } | | . {|except a little trimming in september.| {| } | | {|all work up to this date done in | {| } | | {|normal air. heading advanced to + | {| } | | {|and bulkheaded. | | | | | | rock | | | . | | | | | | | | | | {|heading advanced to + . shut | mixed | | | . {|down in order that line d might have a| | | | {|lead. | | | | | | mixed | | | . {|shut down on account of air shortage. | | | | | | mixed | | | . |shut down on account of air shortage. | | | | | | mixed | | | . |shut down april th to july th, | | | | | . | | | | | | earth | | | . | | | | | | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | mixed | | | . |heading advanced to + . | | | | | | rock | | | . | " " " + . | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | mixed | | | . |shut down until line d shields met. | | | | | | mixed | | | . | | --------------+------+--------+--------+--------------------------------------+ line d, manhattan. --------------+-----------------+---------+---------+------------+------------+ {|top heading | + . | + |dec. , ' |jan. , ' |} {|removing bench | + . | + |jan. , ' |jan. , ' |} rock {|bottom heading | + | + |jan. , ' |feb. , ' |} {|trimming | + | + |mar. , ' |apr. , ' |} {|trimming | + | + |aug. , ' |sept , ' |} | | | | | | rock |bottom heading | + | + |oct. , ' |nov. , ' | | | | | | | mixed |bottom heading | + | + |nov. , ' |dec. , ' | | | | | | | |sliding hood and | | | | | mixed |breasting. rock | + | + |dec. , ' |jan. , ' | |bench | | | | | | | | | | | earth |poling and | + | + |jan. , ' |feb. , ' | |breasting | | | | | | | | | | | | | | | | | earth |poling, breasting| + | + |mar. , ' |mar. , ' | | and shutters | | | | | | | | | | | | | | | | | earth |shutters | + | + |apr. , ' |sept , ' | | | | | | | | | | | | | mixed |bottom bench | + | + |sept , ' |sept , ' | | | | | | | mixed |bottom heading | + | + |oct. , ' |nov. , ' | | | | | | | | | | | | | rock |bottom heading | + | + |nov. , ' |jan. , ' | | | | | | | mixed |bottom heading | + | + |jan. , ' |feb. , ' | | | | | | | mixed |rock cut | + | + |feb. , ' |apr. , ' | | | | | | | rock |middle heading | + | + |apr. , ' |may , ' | | | | | | | rock |middle heading | + | + |may , ' |june , ' | | | | | | | | | | | | | mixed |middle heading | + | + |june , ' |june , ' | | | | | | | mixed |rock cut | + | + |june , ' |july , ' | | | | | | | rock |middle heading | + | + |july , ' |sept , ' | | | | | | | mixed |middle heading | + | + |sept , ' |sept , ' | | | | | | | rock |middle heading | + | + |sept , ' |sept , ' | | | | | | | mixed |rock cut | + | + . |sept , ' |jan. , ' | --------------+-----------------+---------+---------+------------+------------+ --------------+------+--------+--------+--------------------------------------+ | | |rate of | | |number| |progress| | | of | linear |in feet | | material. | days.| feet. |per day.| remarks | --------------+------+--------+--------+--------------------------------------+ {| | | | | {| | | | | rock {| | | . |in normal air. | {| | | | | {| | | | | | | | | | rock | | | . |bottom heading timbered. | | | | | | mixed | | | . | | | | | | | | | | | | mixed | | | . | | | | | | | | | | | | earth | | | . | | | | | | | | | | | | | | | |three days' delay to set shutters in | earth | | | . |top. shut down days to permit | | | | |consolidation of the river bed and to | | | | |repair broken plates. | | | | | | earth | | | . |four days of , delay account of | | | | |flood. | | | | | | mixed | | | . | | | | | | | mixed | | | . |thirteen days' shut-down to put on | | | | |hood. | | | | | | rock | | | . | | | | | | | mixed | | | . | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | rock | | | . |twelve days' delay to repair cutting | | | | |edge. | | | | | | mixed | | | . | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | mixed | | | . | | | | | | | rock | | | . | | | | | | | mixed | | . | . | | --------------+------+--------+--------+--------------------------------------+ openings were made between the headings as follows: tunnel _d_, february th, ; tunnel _b_, march d, ; tunnel _c_, march th, ; tunnel _a_, march th, . it was necessary to cut away the projecting floors of the working compartments before the cutting edges could be shoved together. _contractor's organization._--tunnel operations were carried on continuously for thirteen days out of fourteen, regular work being shut down for repairs on alternate sundays. when the required pressure was more than lb., four gangs of laborers were employed, each gang working two shifts of hours each, with an intermission of hours between the shifts. when the pressure was less than lb., three gangs were employed, each gang covering hours, but with an intermission of about / hour in low pressure for lunch. _air pressures required._--during the greater portion of the work in soft ground, pressure was maintained which would about balance the hydrostatic head at the axis of the tunnel. this required a pressure varying from to lb. per sq. in. above that of the atmosphere. in tunnels _b_ and _d_, at manhattan, during the work in soft ground, pressures as high as lb. were maintained for considerable periods of time; in the firm material near the reef lb. was often sufficient. while removing the broken plates, the pressure was raised for a short time to lb., and was maintained between - / and lb. for a little more than one month. _air supply._--for regular operation the contractor furnished four compressors on each side of the river, each having a rated capacity of , cu. ft. of free air per minute delivered at lb. above normal, when running at the rate of rev. per min. an additional compressor of the same capacity was supplied on each side of the river, in compliance with the requirement for % excess capacity; the additional compressors had also high-pressure air cylinders which could be connected at will, and in which the pressure could be increased to lb., and the air used to supply rock drills, grouting machines, etc. the entire combination on each side of the river, therefore, was rated at , cu. ft. of free air per minute, or a mean of , cu. ft. per heading. its safe working capacity was not far from , cu. ft. per min. the shields broke through rock surface in tunnels _b_, _c_, and _d_, at manhattan, in november and december, . the consumption of air in the four tunnels soon exceeded , cu. ft. for hours, and in tunnel _d_, on several occasions, it exceeded , cu. ft. for a like period. blows had become frequent, and it was evident that the air plant was inadequate for driving four tunnels at once in the open material east of the manhattan rock. work in tunnel _a_, therefore, was not resumed, after the suspension on december th, for about ten months, and tunnel _c_ was also closed down for more than four months of the time between december, , and july, . during this period the capacity of the plant was increased from the rated , cu. ft. of free air per minute, to , . in tunnel _d_ the material had gradually become firmer, with more clay and less escape of air, as the blackwell's island reef was approached, and, at the end of the period, the rock surface was within ft. of the top of the shield; in tunnel _b_, the rock of the reef was still a little below the shield, but the overlying material contained a large proportion of clay and held air very well. tunnel _c_ was still in open material, but, with two lines safe and with the increased air plant, it was deemed best to resume work in tunnel _a_, which was done on october d, . thenceforward work was continuous in all headings until the meeting points with the long island shields were reached. this period, january to october, , inclusive, was the most strenuous of the entire work, particularly the first six months. with one and, at times, two tunnels closed down, the consumption of air in the headings from manhattan was an average of more than , cu. ft. per min. for periods of from to days; it was often more than , cu. ft. for hours, with a maximum of nearly , cu. ft., and doubtless this was exceeded considerably for shorter periods. on several occasions the quantity supplied to a single tunnel averaged more than , cu. ft. per min. for hours. the greatest averages for hours were obtained later in tunnel _a_, after the resumption of work there, and exceeded , cu. ft., but the conditions in the headings of the other lines were then so favorable that the work was carried on continuously in all. the deficiency in the original plant at manhattan was so marked, and the need of driving all headings from long island simultaneously so clear, that it was decided to increase the rated capacity of the long island compressor plant to , cu. ft. of free air per minute, which was , cu. ft. greater than the capacity of the manhattan plant after the latter had been augmented. [illustration: plate lxxii] the earth encountered on emerging from rock, when driving westward from long island, was far more compact and less permeable to air than on the manhattan side, but for a distance of from to ft. immediately east of the reef, it was a clean open sand, and, while the shields were passing through this, the quantity of air supplied to the four headings seldom fell below , cu. ft. per min.; it was usually more than , cu. ft., with a recorded maximum of , cu. ft. although this was greater than ever used on the manhattan side, it was more uniformly distributed among the several headings, and in none equalled the maximum observed on the manhattan side, the largest having been , cu. ft. per min. for hours; it must be remembered, however, that at one time only two tunnels were in progress in the bad material in the tunnels from manhattan. from the foregoing experience, it would seem that the plant finally furnished at long island, having a rated capacity of , cu. ft. of free air per minute, would have been a reasonable compliance with the original actual needs on the manhattan side and _vice versa_; the plant finally developed on the manhattan side, having a rated capacity of , cu. ft. of free air per minute, would have sufficed for the long island side. the total quantity of free air compressed for the supply of the working chambers of the tunnels and the long island caissons was , , , cu. ft., and, in addition, , , , cu. ft. were compressed to between and lb. for power purposes, of which at least % was exhausted in the compressed-air working chambers. the total supply of free air to each heading while under pressure, therefore, averaged about , cu. ft. per min. the quantity of air escaping during a sudden blow-out is apparently much smaller than might be supposed. investigation of a number of cases, showing large pressure losses combined with a long stretch of tunnel supplying a relatively large reservoir of air, disclosed that a maximum loss of about , cu. ft. of free air occurred in min. this averages only a little more than , cu. ft. per min., the maximum recorded supply to one tunnel for a period of hours. of this quantity, however, probably from to % escaped in the first seconds, while the remainder was a more or less steady loss up to the time when the supply could be increased sufficiently to maintain the lowered pressure. very few blows showed losses approaching this in quantity, but the inherent inaccuracy of the observations make the foregoing figures only roughly approximate. [footnote c: _minutes of proceedings_, inst. c. e., vol. cxxx, p. .] special difficulties. the most serious difficulties of the work came near the start. in tunnel _d_ blows and falls of sand from the face were frequent after soft ground was met in the top. about six weeks after entering the full sand face, and before the shutters had been installed, the shield showed a decided tendency to settle, carrying the tunnel lining down with it and resulting in a number of badly broken plates in the bottom of the rings. notwithstanding the use of extremely high vertical leads,[d] the sand was so soft that the settlement of the shield continued for about fifteen rings, the maximum being nearly in. below grade. the hydrostatic head at mid-height of the tunnel was - / lb., and the raising of the air pressure to lb., as was done at this time, was attended with grave danger of serious blows, on account of the recent disturbance of the natural cover by the pulling and re-driving of piles in the reconstruction of the long island ferry slips directly above. it dried the face materially, however, and the shield began to rise again, and had practically regained the grade when the anticipated blow-outs occurred, culminating with the entrance of rip-rap from the river bed into the shield and the flooding of the tunnel with ft. of sand and water at the forward end. the escape of air was very great, and, as a pressure of more than lb. could not be maintained, the face was bulkheaded and the tunnel was shut down for three weeks in order to permit the river bed to consolidate. this was the most serious difficulty encountered on any part of the work, and, coming at the very start, was exceedingly discouraging. during the shut-down the broken plates were reinforced temporarily with steel ribs and reinforced concrete (fig. , plate lxxiii) which, on completion of the work, were replaced by cast-steel segments, as described elsewhere. practically, no further movement of iron took place, and the loss of grade caused by the settlement of the shield, which was by far the largest that ever occurred in this work, was not sufficient to require a change in the designed grade or alignment of the track. work was resumed with the shutters in use at the face as an aid to excavation. the features of extreme seriousness did not recur, but for two months the escape of air continued to be extremely large, an average of , cu. ft. per min. being required on many days during this period. [illustration: plate lxxiii, fig. .--temporary reinforcement of broken plates and removal of a plate in sections.] [illustration: plate lxxiii, fig. .--heavy cast-steel patch attached to bent segment of cutting edge.] [illustration: plate lxxiii, fig. .--inflow of soft clay through shield.] [illustration: plate lxxiii, fig. .--reinforcement of broken plate with long polt and twisted steel rods.] in tunnel _b_, after passing out from under the bulkhead line, in april, , the loss of air became very great, and blow-outs were of almost daily occurrence until the end of june. at the time of the blows the pressure in the tunnel would drop from to lb., and it generally took some hours to raise the pressure to what it was before the blow. during that time regular operations were interrupted. in the latter part of june a permit was obtained allowing the clay blanket to be increased in thickness up to a depth of water of ft. at mean low tide. the additional blanket was deposited during the latter part of june and early in july, and almost entirely stopped the blows. by the end of the month the natural clay, previously described, formed the greater portion of the face, and, from that time forward, played an important part in reducing the quantity of air required. during april and the early part of may the work was under the ferry racks of the long island railroad. the blanket had to be placed by dumping the clay from wheel-barrows through holes in the decking. in tunnel _a_ a bottom heading had been driven ft. in advance of the face at the time work was stopped at the end of . during the ten months of inactivity the seams in the rock above opened. the rock surface was only from to ft. below the top of the cutting edge for a distance of about ft. over the rock there were large boulders embedded in sharp sand. it was an exceedingly difficult operation to remove the boulders and place the polings without starting a run. the open seams over the bottom heading also frequently caused trouble, as there were numerous slides of rock from the face which broke up the breasting and allowed the soft material from above to run into the shield. there were two runs of from to cu. yd. and many smaller ones. [footnote d: the lead of the shield is the angular divergence of its axis from the axis of the tunnel and, in this tunnel, was measured as the offset in ft. it was called + when the shield was pointed upward from grade, and - when pointed downward.] guiding the shields. little difficulty was experienced at any time in driving the shield close to the desired line, but it was much harder to keep it on grade. in rock section, where the cradle could be set far enough in advance to become hard before the shield was shoved over it, there was no trouble whatever. where the cradle could be placed only a very short time before it had to take the weight of the shield, the case was quite different. the shield had a tendency to settle at the cutting edge, and when once pointed downward it was extremely difficult to change its direction. it was generally accomplished by embedding railroad rails or heavy oak plank in the cradle on solid foundation. this often had to be repeated several times before it was successful. in soft ground it was much easier to change the direction of the shield, but, owing to the varying nature of the material, it was sometimes impossible to determine in advance how the shield should be pointed. it was found by experience at manhattan that the iron lining remained in the best position in relation to grade when the underside of the bottom of the shield at the rear end was driven on grade of the bottom of the iron, but if the rate of progress was slow, it was better to drive the shield a little higher. in the headings from long island, which, as a rule, were in soft ground, the cutting edges of the shields were kept from to in. higher, with respect to the grade line, than the rails. the shields would then usually move parallel to the grade line, though this was modified considerably by the way the mucking was done and by the stiffness of the ground at the bottom of the shield. on the average, the shields were shoved by from ten to twelve of the bottom jacks, with a pressure of about , lb. per sq. in. the jacks had -in. plungers, which made the average total force required to shove the shield , , lb. in the soft ground, where shutters were used, all of the twenty-seven jacks were frequently used, and on several occasions the pressure exceeded , lb. per sq. in. with a unit pressure of , lb. per sq. in., the total pressure on the shield with all twenty-seven jacks in operation was , tons. injuries to shields. there were only two instances of damage to the essential structural features of the shields. the most serious was in tunnel _d_ where the cutting edge at the bottom of the shield was forced up a slightly sloping ledge of rock. a bow was formed in the steel casting which was markedly increased with the next few shoves. work was suspended, and a heavy cast-steel patch, filling out the bow, was attached to the bent segments, as shown in fig. , plate lxxiii. no further trouble was experienced with the deformed portion. the other instance was in tunnel _b_, from long island, where a somewhat similar but less serious accident occurred and was treated in a like manner. _bulkheads._--at manhattan, bulkheads had to be built near the shafts before the tunnels could be put under pressure. after ft. of tunnel had been built on each line, the second bulkheads were constructed. the air pressure between the first and second bulkheads was then reduced to between and lb. when the shields had been advanced for , ft., the third set of bulkheads was built. nearly all the broken plates which were removed were located between the first and third bulkheads at manhattan. before undertaking this operation, the doors of the locks in the no. bulkheads were reversed to take pressure from the west. by this means it was possible to carry on the work of dismantling the shields under comparatively low pressure simultaneously with the removal of the broken plates. at long island city the roofs of the caissons served the purpose of the no. bulkheads. two other sets of bulkheads were erected, the first about ft. and the second about , ft. from the shafts. settlement at surface of ground. the driving of such portions of the river tunnels, with earth top, as were under the land section, caused a settlement at the surface varying usually from to in. the three-story brick building at no. east th street required extensive repairs. this building stood over the section of part earth and part rock excavation where the tunnels broke out from the manhattan ledge and where there were a number of runs of sand into the shield. in fact, the voids made by those runs eventually worked up to the surface and caused the pavement of the alley between the buildings to drop or ft. over a considerable area. the tunnels also passed directly under the ferry bridges and racks of the long island railroad at east th street. tunnels _b_ and _d_ were constantly blowing at the time, and, where progress was slow, caused so much settlement that one of the racks had to be rebuilt. tunnel _a_, on the other hand, where progress was rapid, caused practically no settlement in the racks. clay blanket. as previously mentioned, clay was dumped over the tunnels in varying depths at different times. a material was required which would pack into a compact mass and would not readily erode under the influence of the tidal currents of the river and the escape of the great volumes of air which often kept the water in the vicinity of the shields in violent motion. suitable clay could not be found in the immediate vicinity of the work. materials from shooter's island and from haverstraw were tried for the purpose. the government authorities did not approve of the former, and the greater portion of that used came from the latter point. although a number of different permits governing the work were granted, there were three important ones. the first permit allowed a blanket which roughly followed the profile of the tunnels, with an average thickness of ft. on the manhattan side and somewhat less on the long island city side. the second general permit allowed the blanket to be built up to a plane ft. below low water. this proved effective in checking the tendency to blow, but allowed considerable loss of air. finally, dumping was allowed over limited and marked areas up to a plane of ft. below low water. wherever advantage was taken of this last authority, the excessive loss of air was almost entirely stopped. after all the shields had been well advanced out into the river, the blanket behind them was dredged up, and the clay used over again in advance of the shield. soundings were taken daily over the shields, and, if marked erosion was found, clay was dumped into the hole. whenever a serious blow occurred, a scowload of clay was dumped over it as soon as possible and without waiting to make soundings. for the latter purposes a considerable quantity of clay was placed in storage in the pidgeon street slip at long island city, and one or two bottom-dump scows were kept filled ready for emergencies. mr. robert chalmers, who had charge of the soundings for the contractor, states that "the depressions in the blanket caused by erosion due to the escape of air were, as a rule, roughly circular in plan and of a curved section somewhat flat in the center." satisfactory soundings were never obtained in the center of a violent blow, but the following instance illustrates in a measure what occurred. over tunnel _b_, at station + , there was normally ft. of water, ft. of clay blanket, and ft. of natural cover. air was escaping at the rate of about , cu. ft. per min., and small blows were occurring once or twice daily. on june d, soundings showed ft. of water. a depth of ft. of the river bottom had been eroded in about two days. on the next day there were taken out of the shield boulders which had almost certainly been deposited on the natural river bed. clay from the blanket also came into the shields on a number of occasions during or after blows. the most notable occasion was in september, , when the top of the shield in tunnel _d_ was emerging from the east side of blackwell's island reef. the sand in the top was very coarse and loose, and allowed the air to escape very freely. the fall of a piece of loose rock from under the breast precipitated a run of sand which was followed by clay from the blanket, which, in this locality, was largely the softer redredged material. mucking out the shield was in progress when the soft clay started flowing again and forced its way back into the tunnel for a distance of ft., as shown in fig. , plate lxxiii. ten days of careful and arduous work were required to regain control of the face and complete the shove, on account of the heavy pressure of the plastic clay. the clay blanket was of the utmost importance to the work throughout, and it is difficult to see how the tunnels could have been driven through the soft material on the manhattan side without it. the new material used in the blanket amounted to , cu. yd., of which , cu. yd. were removed from over the completed tunnels and redeposited in the blanket in advance of the shields. a total of , cu. yd. of clay was dumped over blows. the total cost of placing and removing the blanket was $ , . iron lining. the standard cast-iron tunnel lining was of the usual tube type, ft. in outside diameter. the rings were in. wide, and were composed of eleven segments and a key. the webs of the segments were - / in. thick in the central portion, increasing to - / in. at the roots of the flanges, which were in. deep, - / in. thick at the root, and - / in. at the edge, and were machined on all contact faces. recesses were cast in the edge of the flanges, forming a groove, when the lining was in place, - / in. deep and about / in. wide, to receive the caulking. the bolt holes were cored in the flanges, and the bosses facing the holes were not machined. the customary grout hole was tapped in the center of each plate for a standard - / -in. pipe. in this work, experience indicated that the standard pipe thread was too fine, and that the taper was objectionable. each segment weighed, approximately, , lb., and the key weighed lb., the total weight being , lb. per lin. ft. of tunnel. fig. shows the details of the standard heavy lining. in addition to the standard cast-iron lining, cast-steel rings of the same dimensions were provided for use in a short stretch of the tunnel, when passing from a rock to a soft ground foundation, where it was anticipated that unequal settlement and consequent distortion and increase in stress might occur, but, aside from the small regular drop of the lining as it passed out of the tail of the shield, no such settlement was observed. two classes of lighter iron, one with -in. web and -in. flanges and the other with - / -in. web and -in. flanges--the former weighing , lb. per lin. ft. of tunnel and the latter, , lb.--were provided for use in the land sections between east avenue and the long island city shafts. two weights of extra heavy segments for use at the bottom of the rings were also furnished. the so-called _xx_ plates had webs and flanges / in. thicker than the standard segment and the _yy_ plates were similarly / in. heavier. the conditions under which they were used will be referred to later. all the castings were of the same general type as shown by fig. . rings tapering / in. and - / in. in width were used for changes in alignment and grade, the former being used approximately at every fourth ring on the ° ' curves. the - / -in. tapers were largely used for changes in grade where it was desired to free the iron from binding on the tail of the shield. still wider tapers would have been advantageous for quick results in this respect. no lug was cast on the segments for attachment to the erector, but in its place the gadget shown on fig. , plate lxx, was inserted in one of the pairs of bolt holes near the center of the plate, and was held in position by the running nut at one end. in the beginning it was expected that the natural shape of the rings would not show more than in. of shortening of the vertical diameter; this was slightly exceeded, however, the average distortion throughout the tunnels being - / in. the erectors were attached to the shield and in such a position that they were in the plane of the center of the ring to be erected when the shove was made without lead and just far enough to permit placing the segments. if the shield were shoved too far, a rare occurrence, the erection was inconvenienced. in driving with high vertical leads, which occurred more frequently, the disadvantage of placing the erector on the shield was more apparent. under such conditions the plane of the erector's motion was acutely inclined to the plane of the ring, and, after placing the lower portion of the ring, it was usually necessary to shove the shield a few inches farther in order to place the upper plates. the practical effect of this action is referred to later. [illustration: fig. .] at first the erection of the iron in the river tunnels interfered somewhat with the mucking operations, but the length of time required to complete the latter was ample for the completion of the former; and the starting of a shove was seldom postponed by reason of the non-completion of a ring. after the removal of the bottom of the diaphragms, permitting the muck cars to be run into the shield and beyond, the two operations were carried on simultaneously without serious interference. the installation of the belt conveyor for handling the soft ground spoil in tunnel _a_ was of special benefit in this respect. preparatory to the final bolt tightening of each ring as erected, a -ton draw-jack, consisting of a small pulling-jack inserted in a light eye-bar chain, was placed on the horizontal diameter, and frequently the erectors were also used to boost the crown of the iron, the object being to erect the ring truly circular. before shoving, a - / -in. turn-buckle was also placed on the horizontal diameter in order to prevent the spreading of the iron, previous to filling the void outside with grout. the approach of the supports for the upper floor of the trailing platform necessitated the removal of these turnbuckles from all but the three leading rings, but if the iron showed a tendency to continue distortion, they were re-inserted after the passage of the trailing platform and remained until the arch of the concrete lining was placed. the cost of handling and erecting the iron varied greatly at different times, averaging, for the river tunnels, $ . per ton for the directly chargeable labor of handling and erecting, to which must be added $ . for "top charges." the cost of repairing broken plates is included in this figure. _broken plates._--during the construction of the river section of the tunnels, a number of segments were found to have been broken while shoving the shield. the breaks, which with few exceptions were confined to the three or four bottom plates, almost invariably occurred on the advanced face of the ring, and rarely extended beyond the bottom of the flange. a careful study of the breaks and of the shoving records disclosed several distinct types of fracture and three principal known causes of breakage by the shield. in the first case, the accidental intrusion of foreign material between the jack head and the iron caused the jack to take its bearings on the flange above its normal position opposite the web of the ring, and resulted usually in the breaking out of a piece of the flange or in several radiating cracks with or without a depression of the flange. these breaks were very characteristic, and the cause was readily recognizable, even though the intruding substance was not actually observed. in the second case, the working of a hard piece of metal, such as a small tool, into the annular space between the iron and the tail of the shield, where it was caught on the bead and dragged along as the shield advanced, was the known cause of a number of broken segments. such breaks had no particular characteristic, but were usually close above the line of travel of the lost tool or metal. their cause was determined by the finding of a heavy score on the underside of the segment or the discovery of the tool wedged in the tail of the shield or lying under the broken plate when it was removed. it is probable that a number of breaks ascribed to unknown causes should be placed in this class. the third cause includes the largest number of breaks, and, while difficult to define closely, is the most interesting. broadly speaking, the breaks resulted from the movements of the shield in relation to the position of the tunnel lining. while shoving through soft ground, it was frequently difficult to apply sufficient power to the lower jacks to complete the full shove of in. on the desired alignment. the shield, therefore, was driven upward at the beginning of the shove, and, as the sand packed in front of the shield and more power was required, it was furnished by applying the upper jacks. the top of the shield was slowly pushed over, and, at the close of the shove, the desired position had been obtained; but the shield had been given a rocking motion with a decided lifting of the tail toward the close of the shove. a similar lifting of the tail occurred when, with high vertical leads, the top of the shield was pushed over in order to place the upper plates of the ring. again, when the shield was driven above grade and it was desired to descend, the passage of the shield over the summit produced a like effect. in all these movements, with the space between the tail of the shield and the iron packed tight with pugging, the upward thrust of the shield tended to flatten the iron in the bottom and occasional broken plates were the result. the free use of the taper rings, placed so as to relieve the binding of the lining on the tail of the shield, forces the tunnel to follow the variations in the grade of the shield, but reduces greatly the injuries to the rings from this action. in tunnel _d_, where very high vertical leads were required through the soft sand, combined with a marked tendency of the shield to settle, the shield was badly cramped on the iron and dragged along it at the top. the bearing of the iron on its soft foundation tended to thrust up the bottom in this case also, as shown by the opening of the bottom cross-joints when the bolts were slackened to relieve the strain during a shove. the anticipated cracks in the crown plates, which have been more frequently observed in other tunnels, did not occur here, and were not found elsewhere except in one place in tunnel _b_ where they were traced to a similar action of the shield. the cracks resulting from the movements of the shield, as briefly described above, in this third case were not confined to any particular type, but occurred more frequently at the extreme end of the circumferential flange than at any other point. the number of broken plates occurring in the river tunnels was , or . % of the total number erected. of these, were found and removed, either before or immediately after a shove, by far the greater number being broken in handling before or during erection. the remaining are considered below. _repair of broken plates._--on the completion of a shove, the tail of the shield lacked about in. of covering the full width of the last ring, and the removal of a plate broken during the shove, therefore, would have exposed the ground at the tail of the shield. with a firm material in the bottom, this introduced no particular difficulties, and, under such conditions, a broken plate was usually removed at once. in the sand, however, and especially on the manhattan side where it was quick and flowing, the removal of a plate was attended with some danger, and such plates were usually left to be removed on the completion of the tunnel. many of these had been reinforced by the use of _xx_, _yy_, and steel segments placed adjacent to the break in the following rings. after the meeting of the shields, the postponed replacement of the broken segments was taken up. the pressure was raised sufficiently to dry thoroughly the sand outside the segments, which were drilled and broken out usually in quarters as shown on fig. , plate lxxiii. a steel segment was then inserted in the ring and drawn into place by turnbuckles. the application of the draw-jack, with a pull of about tons to each end successively, brought the plate to a firm bearing on the radial joints at the ends. where the broken plate was isolated and was reinforced by steel or extra heavy segments in the adjacent ring, the crack, if slight, was simply caulked to insure water-tightness. if, however, the crack was opened or extended to the web of the plate, the cross-flanges were tied together by a - / -in. by -ft. bolt, inserted through the bolt holes nearest the broken flange. the long bolt acted in the nature of a bow string, and was provided at its ends with two nuts set on opposite sides of the cross-joints to replace the standard bolts removed for its insertion. fig. , plate lxxiii shows one of these bolts in place. in addition, all broken plates remaining in the tunnel were reinforced with -in. twisted-steel rods in the concrete lining, also shown in fig. , plate lxxiii. _special construction at river shield junctions._--dismantling the shields was started as soon as they came to rest in their final position with the cutting edges together. the plans contemplated their entire removal, with the exception of the cylindrical skins and cast-steel cutting edges. inside the former the standard tunnel lining was erected to within ft. of the heels of the cutting edges. spanning the latter, and forming the continuous metal tunnel lining, the special construction shown by fig. was built. this consisted of a - / in. rolled-steel ring, ft. long, erected inside the cutting edges, with an annular clearance of in., and two special cast-iron rings shaped to connect the rolled-steel ring with the normal lining. one flange of the special cast-iron rings was of the standard type, the other was returned in. in the form of a ring, the inside diameter of which was the same as the outside diameter of the rolled-steel ring to which it was bolted. the space between the standard and special construction was of varying width at the various shields, and was filled with a closure ring cast to the lengths determined in the field. fig. shows the completed construction. hook-bolts, screwed through threaded holes and buried in to portland cement grout ejected through similar holes, reinforced the rolled-steel ring against external water pressure. in two of the tunnels the concrete lining was carried completely through the junction, and covered the whole construction, while in the remaining two tunnels it was omitted at the rolled-steel ring, leaving the latter exposed and set back about in. from the face of the concrete. [illustration: fig. .] grouting. except as previously noted, the voids outside of the tunnel lining were filled with grout ejected through the grout holes in each segment. the possibility was always present that portland cement, if used for grout in the shield-driven tunnels, would flow forward around the shield and set hard, "freezing" the shield to the rock or the iron lining, or at least forming excrescences upon it, which would render its control difficult. with this in mind, the contractors proposed to substitute an english blue lias lime as a grouting material. grout of fresh english lime containing a moderate quantity of water set very rapidly in air to the consistency of chalk. its hydraulic properties, however, were feeble, and in the presence of an excess of water it remained at the consistency of soft mud. it was not suitable, therefore, as a supporting material for the tunnel. an american lime, made in imitation of the lias lime, but having greater hydraulic properties, was tried, but proved unsatisfactory. two brands of natural cement were also tried and rejected, but a modified quick-setting natural cement, manufactured especially for this work, was eventually made satisfactory, and by far the largest part of the river-tunnel grouting was done with this material mixed to by volume. east of the long island shafts the work which was built without shields was grouted principally with portland cement and sand mixed to by volume. in the river tunnels large quantities of the english lime were used neat as grout over the top of the tunnel in attempts to stop losses of air through the soft ground. it was not of great efficiency, however, in this respect until the voids outside of the lining had been filled above the crown. its properties of swelling and quick setting in the dry sand at that point then became of value. the use of dry lime in the face, where the escaping air would carry it into the voids of the sand and choke them, was much more promptly efficacious in checking the loss. with the exception of the english lime, all grout was mixed to with sand in a cockburn continuous-stirring machine operated by a -cylinder air engine. the grout machine was placed on the lower floor of the trailing platform shown on plate lxxii, while the materials were placed on the upper platform, and, together with the water, were fed into the machine through a hole in the upper floor. the sand was bagged in the yard, and the cars on which the materials were sent into the tunnels were lifted by an elevator to the level of the upper floor of the trailing platform before unloading. great difficulty was experienced in preventing the waste of the fluid grout ahead of the shield and into the tail through the space between it and the iron lining. in a full soft ground section, the first condition did not usually arise. in the full-rock sections the most efficient method of checking the waste was found to be the construction of dams or bulkheads outside the lining between it and the rock surface. for this purpose, at intervals of about ft., the leading ring and the upper half of the preceding one were disconnected and pulled forward sufficiently to give access to the exterior. a rough dam of rubble, or bags of mortar or clay, was then constructed outside the iron, and the rings were shoved back and connected up. in sections containing both rock and soft ground, grout dams were built at the cutting edge at intervals, and were carried up as high as circumstances permitted. the annular space at the tail of the shield was at all times supposed to be packed tight with clay and empty bags, but the pugging was difficult to maintain against the pressure of the grout. for a time, / -in. segmental steel plates, slipped down between the jackets and the iron, were used to retain the pugging, but their displacement resulted in a number of broken flanges, and their use was abandoned. in their place, -in. segmental plates attached to the jack heads were substituted with more satisfactory results. notwithstanding these devices, the waste of grout at the tail was very great. the soft ground material on various portions of the work acted very differently. the clay and "bull's liver" did not cave in upon the iron lining for several hours after the shield had passed, sometimes not for a day or more, which permitted the space between it and the iron to be grouted. the fine gray or beach sand and the quicksand closed in almost at once. the quicksand has a tendency to fill in under the iron from the sides and in places to leave a cavity at about the horizontal diameter which was not filled from above, as the sand, being dried out by the air, stood up fairly well and did not cave against the iron, except where nearly horizontal at the top. the total quantity of grout used on the work was equivalent in set volume to , bbl. of to portland cement grout, of which , bbl. were ejected through the iron lining, an average of . bbl. per lin. ft. the cost of grout ejected outside of the river tunnels was cents per bbl. for labor and $ . for "top charges." east of the long island shaft the corresponding costs were $ . and $ . , the difference being partly due to the large percentages of work done in the normal air at the latter place. caulking and leakage. up to august, , the joints between the segments of the cast-iron lining were caulked with iron filings and sal ammoniac, mixed in the proportion of to by weight. with the air pressure balancing the hydrostatic head near the tunnel axis, it was difficult to make the rust-joint caulking tight below the axis against the opposing water pressure; this form of caulking was also injured in many places by water dripping from service pipes attached to the tunnel lining. a few trials of lead wire caulked cold gave such satisfactory results that it was adopted as a substitute. pneumatic hammers were used successfully on the lead caulking, but were only used to a small extent on the rust borings, which were mostly hand caulked. immediately before placing the concrete lining, all leaks, whether in the rust borings or lead, were repaired with lead, and the remainder of the groove was filled with to portland cement mortar, leaving the joints absolutely water-tight at that time. the subsequent development of small seepages through the concrete would seem to indicate that the repair work should have been carried on far enough in advance of the concreting to permit the detection of secondary leaks which might develop slowly. the average labor cost chargeable against the caulking was cents per lin. ft., to which should be added . cents for "top charges." unfortunately, it was necessary to place the greater part of the concrete lining in the river tunnels during the summer months when the temperature at the point of work frequently exceeded °; and the temperature of the concrete while setting was much higher. this abnormal heat, due to chemical action in the cement, soon passed away, and, with the approach of winter, the contraction of the concrete resulted in transverse cracks. by the middle of the winter these had developed quite uniformly at the ends of each -ft. section of concrete arch as placed, and frequently finer cracks showed at about the center of each -ft. section. while the temperature of the concrete was falling, a like change was taking place in the cast-iron lining, with resulting contraction. the lining had been erected in compressed air, the temperature of which averaged about ° in winter and higher in summer. compressed air having been taken off in the summer of , the tunnels then acquired the lower temperature of the surrounding earth, slowly falling until mid-winter. the contraction of the concrete, firmly bedded around the flanges of the iron, and showing cracks at fairly uniform intervals, probably localized the small corresponding movements of the iron near the concrete cracks, and resulted in a loosening of the caulking at these points. with the advent of cold weather, damp spots appeared in numerous places on the concrete, and small seepages showed through quite regularly at the temperature cracks, in some cases developing sufficiently to be called leaks. only a few, however, were measurable in amount. early in january small brass plugs were firmly set on opposite sides of a large number of cracks, and caliper readings and air temperature observations were taken regularly throughout the winter and spring. the widths of the cracks and the amount of leakage at them increased with each drop in temperature and decreased as the temperature rose again, but until spring the width of the cracks did not return to the same point with each return of temperature. the leakage was similar in all four tunnels, but was largest in amount in tunnel _d_, where, at the beginning of february, the ordinary flow was about . cu. ft. per sec., equivalent to . cu. ft. per sec. per lin. ft. of tunnel. of this amount . cu. ft. per sec. could be accounted for at eight of the cracks showing measurable leakage, leaving . cu. ft. per sec. or . cu. ft. per sec. per lin. ft. of tunnel to be accounted for as general seepage distributed over the whole length. it was not feasible to stop every leak in the tunnel, most of which were indicated simply by damp spots on the concrete; a rather simple method was devised, however, for stopping the leaks at the eight or ten places in each tunnel where water dripped from the arch or flowed down the face of the concrete. the worst leak in any tunnel flowed about . cu. ft. per sec. to stop these leaks, rows of -in. holes, at about -in. centers, were drilled with jap drills through the concrete to the flange of the iron. these rows were from to ft. long, extending ft. or more beyond the limits of the leak. the bottoms of the holes were directly on the caulking groove and the pounding of the drill usually drove the caulking back, so that the leak became dry or nearly so after the holes were drilled. if left alone the leaks would gradually break out again in a few hours or a few days and flow more water than before. they were allowed to do this, however, in only a few cases as experiments. after the holes were drilled, the bottom in. next the flange was filled with soft neat cement mortar. immediately on top of this was placed two plugs of neat cement about - / in. long, which were or hours old and rather hard. each was tamped in with a round caulking tool of the size of the hole driven with a sledge hammer. on top of this were driven in the same way two more plugs of neat cement of the same size, which were hard set. these broke up under the blows of the hammer, and caulked the hole tight. when finished, the tamping tool would ring as though it was in solid rock. great pressure was exerted on the plastic mortar in the bottom of the hole, which resulted in the re-caulking of the joint of the iron. no further measurable leakage developed in the repaired cracks, during a period of four months, and the total leakage has been reduced to about . cu. ft. per sec. in each tunnel, an average of . cu. ft. per sec. per lin. ft. sump and pump chambers. to take care of the drainage of the tunnels, a sump with a pump chamber above it was provided for each pair of tunnels. the sumps were really short tunnels underneath the main ones and extending approximately between the center lines of the latter. they were ft. - / in. in outside diameter and ft. long. the water drops directly from the drains in the center lines of the tunnels into the sumps. above the sumps and between the tunnels, a pump chamber ft. in. long was built. above the end of the latter, opposite the sump, a cross-passage was constructed between the bench walls of the two tunnels. this passage gives access from either tunnel through an opening in the floor to the pump chamber and through the latter to the sump. from the preliminary borings it was thought that the sumps were located so that the entire construction would be in rock. this proved to be the case on tunnels _c_ and _d_, but not on tunnels _a_ and _b_. the position of the rock surface in the latter is shown by fig. . after the excavation was completed in tunnel _b_, january st, , the plates were removed from the side of the tunnel at the cross-passage, and a drift was driven through the earth above the rock surface across to the lining of tunnel _a_. the heading was timbered as shown by fig. . there was practically no loss of air from the drift, but the clay blanket had been removed from over this locality and the situation caused some anxiety. in order to make the heading as secure as possible, the -in. i-beams, shown on fig. , were attached to the lining of the two tunnels. the beams formed a support for the permanent concrete roof arch of the passage, which was placed at once. at the same time plates were removed from the bottom in tunnel _b_ over the site of the sump, and a heading was started on the line of the sump toward tunnel _a_. as soon as the heading had been driven beyond the center line of the pump chamber, a bottom heading was driven from a break-up westward in the pump chamber and a connection was made with the cross-passage. the iron lining of the pump chamber was next placed, from the cross-passage eastward. the soft ground was excavated directly in advance of the lining, and the ground was supported by polings in much the same manner as described for shield work. on account of bad ground and seams of sand encountered in the rock below the level of the cross-beams, the entire west wall of the pump chamber was placed before enlarging the sump to full size. this was also judicious, in order to support as far as possible the iron lining of the tunnels. the sump was then excavated to full size. the iron lining of the sump and the east wall of the pump chamber were placed as soon as possible. the voids outside the iron lining of the sump and the pump chamber were filled as completely as possible with concrete, and then thoroughly grouted. finally, the concrete lining was put in place inside of the iron. as shown by fig. , the excavation of these chambers left a considerable portion of the iron lining of the tunnels temporarily unsupported on the lower inner quarter. to guard against distortion, a system of diagonals and struts was placed as shown. the floor of the pump chamber was water-proofed with felt and pitch in a manner similar to that described for the caissons at long island city. it was not possible to make the felt stick to the vertical walls with soft pitch, which was the only kind that could be used in compressed air, and, therefore, the surfaces were water-proofed by a wall of asphalt brick laid in pitch melting at ° fahr. forms were erected on the neat line, and the space to the rock was filled with concrete making a so-called sand-wall similar to that commonly used for water-proofing with felt and pitch. the bricks were then laid to a height of four or five courses. the joints were filled with pitch instead of mortar. sheets of tin were then placed against the face of the wall and braced from the concrete forms. as much pitch as possible was then slushed between the brick and the sand-wall, after which the concrete in the main wall was filled up to the top of the water-proofing course. the tin was then withdrawn and the operation repeated. this method was slow and expensive, but gave good results. ordinary pitch could not be used on account of the fumes, which are particularly objectionable in compressed air. the ° pitch was slightly heated in the open air before using. [illustration: fig. .] the sump and pump chamber on tunnels _c_ and _d_ differed from the one described only in minor details; but, being wholly constructed in rock, presented fewer difficulties and permitted a complete envelope of water-proofing to be placed in the top. concrete lining. the placing of concrete inside the iron tube was done by an organization entirely separate from the tunneling force. a mixing plant was placed in each of the five shafts. the stone and sand bins discharged directly into mixers below, which, in turn, discharged into steel side-dump concrete cars. all concrete was placed in normal air. the first step, after the iron lining was scraped clean and washed down and all leaks were stopped, was the placing of biats, marked _b_ on plate lxxiv. these were made up of a by -in. yellow pine timber, ft. long, with two short lengths of the same size spliced to its ends by pieces of -in. channels, ft. in. long, clamped upon the sides. these biats were placed every ft. along the tunnel in rings having side keys. next, a floor, ft. wide, was laid on the biats and two tracks, of -in. gauge and - / -ft. centers, were laid upon the floor. there were three stages in the concreting. fig. , plate lxxiv, shows the concrete in place at the end of the first, and fig. , plate lxxiv, at the end of the second stage. the complete arch above the bench walls was done in the last operation. two by -in. soldiers (_ss_ in figs. and , plate lxxiv) were fastened to each biat and braced across by two horizontal and two diagonal braces. to each pair of soldiers a floor template, _t_, was then nailed. the form for the center drain was then suspended as shown in fig. , plate lxxiv. three pieces of shuttering, _fff_, ft. long, were then nailed to the bottom of the soldiers. one is all that would have been needed for the first concrete placed, but it was easier to place them at this stage than later, when there was less room. three rough shutters were also nailed to the curved portion for the floor template. opposite each biat, a bracket, _bb_, was then nailed, which carries a set of rough boards which formed the risers for the duct steps. everything was then ready for concreting except that, where refuge niches occurred, a form for the portion of the niche below the seat was nailed to the shuttering. this form is shown at _r_ in fig. , plate lxxiv. [illustration: plate lxxiv] the concrete was dumped down on each side from side-dump cars standing on the track, and, falling between the risers for the duct steps, ran or was shoveled under the forms and down into the bottom. the horizontal surface on each side the center drain was smoothed off with a shovel. the workmen became very skillful at this, and got a fairly smooth surface. this concrete was usually placed in lengths of or ft. after setting for about hours, the brackets, _bb_, were removed, together with the shuttering on the steps. the triangular pieces, _t_ in fig. , plate lxxiv, were not removed until later. instead, a board was laid upon this lower step on which the duct layers could work. this and the triangular piece were not removed until just before the bench concrete was placed. this was important, as otherwise the bond between the old and new concrete would be much impaired by dirt ground into the surface of the old concrete. the ducts were then laid, as shown in fig. , plate lxxiv. the remaining shutters for the face of the bench walls were then placed. the remainder of the forms for the refuge niches, _rr_, in fig. , plate lxxiv, were nailed to the shutters, the steel beam over the niche was laid in place, the forms for the ladders, _l_ in fig. , plate lxxiv, which occur every ft., were tacked to the shutters, the shutters and forms were given a coat of creosote oil, and then all was ready for placing the bench concrete. the specifications required a -in. mortar face to be placed on all exposed surfaces and the remainder to be smoothed with a trowel and straight-edge. after about hours, the biats were blocked up on the bench, and all forms between the bench walls below the working floor were removed. the centering for the arch concrete consisted of simple by - / by / -in. steel-angle arch ribs, curved to the proper radius, spaced at -ft. intervals. each rib was made up of two pieces spliced together at the top. two men easily handled one of these pieces. after splicing, the rib was supported by four hanger-bolts fastened to the iron lining as shown in fig. , plate lxxiv. in the early part of the work, two additional bolts were used about half way up on the side between the upper and lower hanger-bolts. it was soon found that by placing the strut between the tunnel lining and the crown of the rib, these hanger-bolts could be dispensed with. the lagging was of -in. dressed yellow pine, in. wide, and in -ft. lengths. each piece had three saw cuts on the back, from end to end, allowing it to be bent to the curve of the arch; it was kept curved by an iron strap screwed to the back. the arches were put in, either in , or -ft. lengths, depending on what was ready for concrete and what could be done in one continuous working. the rule was that when an arch was begun, the work must not stop until it was finished. an arch length always ended in the middle of a ring. the lagging was placed to a height of about ft. above the bench before any concreting was done. when the concrete had been brought up to that point, lagging was added, one piece at a time, just ahead of the concrete, up to the crown, where a space of about in. was left. when the lagging had reached the upper hanger-bolts, they were removed, which left only the two bottom bolts fixed in the concrete. most of these were unscrewed from the eye and saved, as tin sleeves were placed around them before concreting. two cast-iron eyes were lost for every ft. of tunnel. to place the key concrete, a stage was set up in the middle of the floor, and, beginning at one end, about ft. of block lagging was placed. over this, concrete was packed, filling the key as completely as possible. this was done partly by shoveling and using a short rammer, and partly by packing with the hands by the workmen, who wore rubber gloves for the purpose. another ft. of lagging was then placed, and the operation was repeated, and thus working backward, foot by foot, the key was completed. this is the usual way of keying a concrete arch, but in this case the difficulty was increased by the flanges of the iron lining. it was practically impossible to fill all parts of the pockets formed by these flanges. to meet this difficulty, provision was made for grouting any unfilled space. as the concrete was being put in, tin pipes were placed with their tops nearly touching the iron lining, and their bottoms resting on the lagging. each pocket was intended to have two of these pipes, one to grout through and the other to act as a vent for the escape of air. each center key ring had six pipes, and each side key had eight. the bottoms of the pipes were held by a single nail driven half way into the lagging. this served to keep the pipes in position and to locate them after the lagging was taken down. the cost of labor in the tunnels directly chargeable to concrete was $ . per cu. yd. the top charges, exclusive of the cost of materials (cement, sand, and stone), amounted to $ . . electric conduits. in one bench wall of each tunnel there were fifteen openings for power cables and in the other, between the river shafts, there were forty openings for telephone, telegraph, and signal cables. east of the long island shaft, the number of the latter was reduced to twenty-four. the telephone ducts were all of the four-way type. the specifications required that the power ducts should have an opening of not less than - / in., nor more than - / in., and that after laying they should pass a -ft. mandrel, - / in. at the leading end and - / in. at the other. the outside dimension was limited between and - / in. the openings of the four-way ducts were required to be not less than - / in., nor more than - / in., and after laying to pass a -ft. mandrel, - / in. at the leading end and - / in. at the other. the outside dimensions were limited between and - / in. all were to be laid in / -in. beds of mortar. the specifications were not definite as to the shape of the opening, but those used were square with corners rounded to a radius of / in. the four-ways were ft. long, and the singles, in. a study of the foregoing dimensions will show that the working limits were narrow. such narrow limits would not pay for the ordinary conduit line in a street, where there is more room. in the tunnel greater liberality meant either reducing the number of conduits or encroaching on the strength of the concrete tunnel lining. the small difference of only / in. in the size of the mandrel, or a clearance of only / in. on each side, no doubt did increase the cost of laying somewhat, though not as much as might at first be supposed. all bottom courses were laid to a string, in practically perfect line and grade, and all joints were tested with mandrels which were in all openings, and pulled forward as each piece of conduit was laid. as the workmen became skillful, the progress was excellent. all costs of labor in the tunnel chargeable to duct laying amounted to $ . per ft. of duct; top charges brought this up to $ . . the serious problem was to guard against grout and mortar running into the duct opening through the joints from the concrete, which was a rather wet mixture. each joint was wrapped, when laid, with canvas, weighing oz. per sq. yd., dipped in cement grout immediately before using. these wraps were in. wide, and were cut long enough to go around the lap about the middle of the duct. as soon as all the ducts were laid, the entire bank was plastered over with fairly stiff mortar, which, when properly done, closed all openings. the plastering was not required by the specifications, but was found by the contractor to result in a saving in ultimate cost. the concrete on the two sides of the bank of ducts was bonded together by by / -in. steel bonds between the ducts, laid across in horizontal joints. both ends were split into two pieces, in. long, one of which was turned up and the other down. these bonds projected - / in. into the concrete on either side. where the bond came opposite the risers of the duct step, against which the ducts were laid, recesses were provided for the projecting bond. this was done by nailing to the rough shutters for the steps a form which when removed left a dove-tailed vertical groove. this form was made in two pieces, one tapering inward and the other with more taper outward. as the bonds were placed, these grooves were filled with mortar. the ducts usually received their final rodding with the specification mandrel a month or more after they were laid, after which all openings into splicing chambers were stopped by wooden plugs, in. long tapering from - / in. at one end to - / in. at the other end, and shaped to fit the opening tightly. at first the plugs were paraffined, to keep them from swelling and breaking the ducts, but were not successful, as the paraffin lubricated them so that they would not stay in place. they were expensive, and there was some swelling in the best that were obtained. a better plug was made by using no paraffin, but by making six saw cuts, three horizontal and three vertical, in the larger end, cutting to within about in. of the smaller end. the swelling of the wood was then taken up by the saw cuts and the spring of the wood. the splicing chambers are at -ft. intervals. they are ft. long, ft. in. high, with a width varying from ft. in. at the top to ft. in. at the bottom. american society of civil engineers instituted transactions paper no. the new york tunnel extension of the pennsylvania railroad. by charles w. raymond, m. am. soc. c. e.[a] some time before the appointment of the board of engineers which supervised the designing and construction of the new york tunnel extension of the pennsylvania railroad, the late a. j. cassatt, then president of the company, said to the writer that for many years he had been unable to reconcile himself to the idea that a railroad system like the pennsylvania should be prevented from entering the most important and populous city in the country by a river less than one mile wide. the result of this thought was the tunnel extension project now nearly completed; but it is only in recent years that new conditions have rendered such a solution of the problem practicable as well as desirable. previously a tunnel designed for steam railroad traffic, to enter new york city near christopher street, was partly constructed, but the work was abandoned for financial reasons. then plans for a great suspension bridge, to enable all the railroads reaching the west shore of the north river to enter the city at the foot of d street, were carefully worked out by the north river bridge company. the pennsylvania railroad company gave this project its support by agreeing to pay its _pro rata_ share for the use of the bridge; but the other railroads declined to participate, and the execution of this plan was not undertaken. new operating conditions, resulting from the application of electric traction to the movement of heavy railroad trains, which had been used initially in tunnels by the baltimore and ohio railroad and was subsequently studied and adopted by railroads in europe, made it possible to avoid the difficulty of ventilation connected with steam traction in tunnels, and permitted the use of grades practically prohibitive with the steam locomotive. the practicability of the tunnel extension project finally adopted was thus assured. the acquisition of the control of the long island railroad by the pennsylvania railroad company, which occurred in , introduced new and important elements into the transportation problem, from a freight as well as a passenger standpoint. previously, the plans considered had for their only object the establishment of a convenient terminus in new york, to avoid the delays and difficulties involved in the necessity of transporting passengers and freight across the north river. when the long island railroad became practically a part of the pennsylvania system, it was possible and desirable to extend the project so as to provide, not only for a great prospective local traffic from all parts of long island, but also for through passenger and freight traffic to the new england states, and to and from all points on the pennsylvania system, thus avoiding the long ferriage from jersey city around the harbor to the harlem river. this paper has for its subject the new york tunnel extension project, and is intended merely as an introduction to the detailed accounts of the construction of the various divisions of the line to be given in succeeding papers prepared by the engineers who actively carried out the work. the project, however, forms the most important part of the comprehensive scheme adopted by the pennsylvania railroad company for conducting its traffic into and through new york city, and a brief description of this general plan is therefore necessary in order that the relations of the tunnel line to the other parts of the transportation project may be clearly understood. general plan for traffic facilities at new york. the component elements of the general plan outlined by the late a. j. cassatt, president, in his open letter to the board of rapid transit railroad commissioners of the city of new york, dated january th, , are indicated on fig. , and may be briefly summarized as follows: _ ._--the pennsylvania tunnel and terminal railroad, generally referred to as the new york tunnel extension of the pennsylvania railroad. this line begins near newark, n. j., crosses the hackensack meadows, and passes through bergen hill and under the north river, the borough of manhattan, and the east river to the large terminal yard, known as sunnyside yard, in long island city, borough of queens, new york. the line will be more fully described elsewhere. _ ._--the electrification of the long island railroad within the city limits. _ ._--the pennsylvania freight terminal yard and piers at greenville, n. j., connecting by ferry with the bay ridge terminal of the long island railroad. _ ._--the bay ridge improvement of the long island railroad from east new york to bay ridge. _ ._--yards for increasing the freight facilities in the boroughs of brooklyn and queens. _ ._--the atlantic avenue improvement in brooklyn, involving the removal of the steam railroad surface tracks and the extensive improvement of the passenger and freight station at flatbush avenue. _ ._--the new york connecting railroad, extending through a part of the borough of queens and crossing the east river by a bridge at ward's and randall's islands to port morris, n. y. _ ._--the glendale cut-off of the long island railroad. _ ._--new piers and docks in newtown creek at its confluence with the east river. _ ._--electrification of the united railroads of new jersey division from newark to jersey city. the parts sustained by these elements in the work of transportation and distribution are briefly as follows: the new york tunnel extension is essentially a passenger line, although the company has not only the legal powers but also the facilities for making it a through route for freight if desired. it will transport passengers to and from the centrally located station at d street and seventh avenue in new york city, joining the long island system at sunnyside yard, and, by means of the new york connecting railroad, it will form a link in the through traffic line, connecting the whole pennsylvania system with the new england states. this line has been designed for the safe and expeditious handling of a large volume of traffic. the requirements include handling the heaviest through express trains south and west from the main line as well as the frequent and lighter local-service trains. for through service the locomotive principle of operation has been adhered to, that is, electric locomotives will take up the work of the steam locomotives at the interchange yard at harrison, n. j., and, for excursion and suburban service to nearby towns, provision will be made for electric locomotives, or by operation of special self-propelled motor cars in trains, the project being planned to give the greatest flexibility in method of operation to meet the growing demand in the best way. the new york connecting railroad has important functions both for freight and passenger service. when constructed it will be about miles long, and will form a part of the line to the new england states for through passenger and freight service, and also carry local freight to and from sunnyside yard and brooklyn, and all points on long island. by means of this line it will be possible to make the brooklyn station at flatbush avenue a station on the through system for new england as well as the western states. [illustration: fig. . (full page image) map of the pennsylvania r. r. co's new york tunnel extension and connections.] the initial equipment of the western division of the long island railroad for electric traction has been made in advance of the opening of the tunnel line in order to take care of the requirements of the atlantic avenue improvement. this improvement involved the elimination of grade crossings within the city of brooklyn and the conversion of the railroad line which was previously on the surface of the streets to part subway and part elevated line from the flatbush avenue terminal to east new york station, a distance of - / miles. one of the requirements of this improvement was that the motive power should be changed to some form of power not involving combustion. this led to the adoption of electricity, and, in order to meet operating necessities, involved the electrification of connecting lines beyond the improvement proper, so that local service could be handled to the end of the runs without changing the motive power. the extent of the electrification thus required was found to be about single-track miles. this extensive electrification work was undertaken and completed in the summer of , upon the completion of the atlantic avenue improvement proper, and since that time has been in successful operation. on the near approach of the construction of the new york terminal improvement, plans for additional electrification on the long island railroad were made, and the work is now in progress on the extensive additions required to couple up the tunnel extension with the various lines centering at the long island city terminus. the bay ridge improvement of the long island railroad comprises the readjustment of the right of way and the establishment of new grades in order to do away with grade crossings from the freight terminal at bay ridge to a junction with the new york connecting railroad at east new york, a distance of . miles. it also provides for the re-location of the line and the elimination of grade crossings on the branch running to manhattan beach, a distance of . miles. the work is being executed without interrupting traffic, and in all about grade crossings will be abolished. this improvement became necessary in order to provide for the rapid extension of population into the suburban districts and for the present and future requirements of the section, to establish municipal conveniences and facilities, and to open additional streets across the right of way. to accomplish these ends, the line has been built in cuts and on embankments, there being about . miles of the former, . miles of the latter, and a tunnel, , ft. long, where the line crosses the atlantic avenue improvement. the atlantic avenue improvement, as mentioned above, involved the removal of the railroad tracks from the street surface for a distance of about - / miles. this was done by constructing a series of elevated and subway structures, there being about . miles of the former, . miles of the latter, and . mile of approaches, eliminating more than grade crossings. in the light of recent developments, it may be of interest to note that one of the reasons for establishing a combination elevated and subway line was that, at the time the improvement was projected, no underground railroad in the country, of similar length and carrying a heavy volume of local traffic, was operated by electricity, and public sentiment was against the operation of the entire length of the line underground by steam power. this improvement also provided for depressing the entire flatbush avenue station and a freight yard. as the work progressed, the original plans for the station were greatly enlarged, the remodeled station covering about city lots. the main point of passenger distribution is the new york station. other important stations will be flatbush avenue, brooklyn; jamaica, long island, where the changes to and from electric motive power will be made; and newark, n. j. many other places, including the seaside resorts on long island and in new jersey, will feel the benefits of the direct tunnel railroad into and through new york city. the glendale cut-off will materially shorten the route and running time from new york through the tunnels to rockaway beach. the plans contemplate that passengers to and from the lower part of manhattan will be carried by the steam line between newark and jersey city and cross the north river by ferry or the cortlandt street tunnels of the hudson company. eventually, the old main line will be electrified and supersede the steam service between newark and jersey city. the greenville yard is the most important point for the receipt, transmission, and distribution of freight. from this point freight can be transported, without breaking bulk, by a comparatively short car-ferry to the long island railroad terminus at bay ridge, and thus a very large part of the pennsylvania railroad company's floatage in new york harbor and the east river will be abolished, the floatage distance being reduced in the case of the new england freight from about to miles. this traffic will be routed from bay ridge _via_ the long island railroad to a connection with and thence over the new york connecting railroad to the new york, new haven and hartford railroad at port morris, n. y. as the facilities for the handling of freight in the boroughs of brooklyn and queens had become insufficient for taking care of the prospective traffic, eleven new local delivery yards, having a combined area of about , city lots, have been established, and three existing yards are to be improved and enlarged so as to give a combined area of about city lots. of these new yards, the bay ridge freight terminal, containing about city lots, is the largest; its functions have been described above. there is a freight terminal at east new york ft. wide and a mile long, containing about city lots, which will be the distributing point of freight for the entire east new york section. this yard is depressed, and will be crossed by six viaducts carrying city streets. the north shore freight yard, containing city lots, is connected with the montauk division by an overhead construction, known as the montauk freight cut-off, whereby all freight traffic to jamaica may be kept out of the way of the jamaica passenger traffic from the tunnels. it may be of interest to indicate briefly how much has already been accomplished in the execution of this general plan, and what still remains to be done for its completion. the larger part of the electrification of the long island railroad and the elimination of grade crossings within the built-up city limits, the atlantic avenue improvement, and the yard and piers at greenville, have been completed. the sunnyside yard and the glendale cut-off will be completed during the next twelve months. on the tunnel and terminal railroad the embankment and bridge work across the hackensack meadows and all the tunnels and excavation from the west side of bergen hill to long island city, except a short section near the eastern end of the line, have been completed. the new york station and other buildings and facilities connected therewith are well advanced. the laying of the track, the electrification of the line, and the installation of the signaling and lighting systems are under way. it is anticipated that the line will be ready for operation in the spring of . report has been made to the public service commission that a large part of the right of way for the new york connecting railroad has been obtained, and more than $ , , has been spent by this railroad. the piers and docks at newtown creek and the electrification of the line from newark to jersey city are not yet actively under way. estimated cost of the improvements. as appears from the foregoing statement, only parts of the improvements contemplated in the general scheme have been completed, others are in progress, and others have not yet been commenced. it is therefore impossible at the present time to make a close estimate of the total expenditure involved in the execution of the entire scheme. the following estimate of the cost of the pennsylvania railroad company's improvements in the new york district when fully completed is based on the best information now available: new york tunnel extension and station, including interchange yards at harrison, n. j., and sunnyside, l. i., p. t. & t. r. r. co. $ , , long island railroad electrification, bay ridge and atlantic avenue improvements, glendale cut-off, freight yards, and new equipment , , new york connecting railroad, to be built jointly by the pennsylvania r. r. co. and the new york, new haven and hartford r. r. co., about , , pennsylvania railroad improvements in the state of new jersey, electrification of line from jersey city to park place, newark, greenville freight line and terminal on new york bay , , ------------ total $ , , corporate organization and franchise conditions. as the tunnel extension lies partly in the state of new jersey and partly in the state of new york, it was necessary to charter two companies, each covering the territory within the state to which it belonged. the new jersey corporation was entitled the pennsylvania, new jersey and new york railroad company, and the new york corporation, the pennsylvania, new york and long island railroad company. these organizations were completed early in . subsequently, after the tunnels had been joined under the north river, the companies were consolidated, on june th, , and thereby formed the present company under the name of the pennsylvania tunnel and terminal railroad company, a corporation of both states. mr. cassatt, president of the pennsylvania, new york and long island railroad company, made application in its behalf for a franchise to extend the lines of the pennsylvania railroad by tunnels under the north river to a passenger station to be erected in new york city and thence under the east river to a connection with the long island railroad, on may th, . the franchise for that part of the tunnel line which is within the state of new york, that is, from the boundary line between new york and new jersey, in the hudson river, to the eastern terminus at sunnyside yard, long island, is contained in the certificate issued by the board of rapid transit railroad commissioners of the city of new york on october th, . the essential features of the franchise have been summarized substantially as follows in the report of the committee of the board of rapid transit railroad commissioners of the city of new york, dated june th, : _first._--a grant by the city in perpetuity of rights, subject, however, to a periodic readjustment of payments at intervals of twenty-five years, as follows: (_a_) to construct and operate a railroad of two tracks from the boundary between new york and new jersey under the hudson river opposite the westerly foot of thirty-first street, borough of manhattan, thence running under the hudson river and thirty-first street to the east river and under the east river to a terminus in queens borough. the company is permitted on notice within ten years to give up the right to these two tracks. (_b_) a like right for a railroad of two tracks beginning near the same point under the hudson river, thence running under thirty-second street to the east river, and under that river to the terminus in queens borough, with a right for two additional tracks in thirty-second street, west of ninth avenue, and one additional track between seventh and fifth avenues in manhattan. (_c_) a like right for a railroad of two tracks beginning at the station terminal site at thirty-third street and seventh avenue and thence running under thirty-third street and the east river to the terminal in queens borough, with a right for one additional track on thirty-third street, between seventh and fifth avenues. (_d_) a right to maintain a terminal station occupying the four blocks bounded by thirty-first street, seventh avenue, thirty-third street and ninth avenue, the lots on the east side of seventh avenue between thirty-first and thirty-third streets, and the underground portions of thirty-first and thirty-third streets, between seventh and eighth avenues and between eighth and ninth avenues, the company having itself acquired the land included in such four blocks and lots on the east side of seventh avenue. (_e_) to occupy for such terminal facilities all of thirty-second street lying between the westerly side of seventh avenue and the easterly side of eighth avenue, and between the westerly side of eighth avenue and the easterly side of ninth avenue. as soon as the statutory right of the city authorities to make the conveyance shall be put beyond doubt the railroad company is obliged to buy such two portions of thirty-second street, which will then become completely dedicated to the purposes of their station. (these portions of thirty-second street were subsequently purchased by the railroad company.) (_f_) to have along such routes the necessary facilities for the operation of passenger and freight trains, including telegraph wires and the various wires and cables for the distribution of power, heat, and light. _second._--the requirement of the consent of the mayor, the board of aldermen, the board of estimate and apportionment, and the other authorities of the city having control of the streets. _third._--the obligation of the pennsylvania company to begin construction within three months after obtaining the necessary consents and complete the railroad within five years after construction shall begin, except the route under thirty-first street, for the completion of which the company is allowed ten years after the completion of the remainder of the railroad. _fourth._--payments by the pennsylvania company for the first twenty-five years, as follows: a rental of $ per annum for the right to occupy land under the hudson and east rivers outside of pier lines. a rental for ground within pier lines and for underground portions of streets in manhattan borough, at fifty cents per linear foot of single track per annum, for the first ten years, and during the next fifteen years one dollar per annum per linear foot. a rental for ground within pier lines and for underground portions of streets in queens borough at one-half the rates payable for manhattan borough. a rental for underground portions of thirty-first and thirty-third streets, between seventh and eighth avenues, and between eighth and ninth avenues (such portions extending almost up to the surface, except under the south sidewalk of thirty-first street and north sidewalk of thirty-third street) at $ , per annum for the first ten years, and at $ , per annum for the next fifteen years. for the portions of thirty-second street, between seventh and eighth avenues, and between eighth and ninth avenues, when the statutory power of the city to make a sale shall be put beyond doubt, the city is to sell and the railroad company is required to buy such portions for the sum of $ , . the rentals for river and track rights begin at the date of operation. for the underground spaces under thirty-first and thirty-third streets, used for station extension, the rentals begin at the commencement of construction, or when the company entered thereon. such annual payments may be summarized as follows: +===============================================+=========================+ | | first | next | | | years. | years. | |-----------------------------------------------+------------+------------+ |for river rights | $ . | $ . | |for tunnel rights in manhattan borough, being | | | | , ft. (partly estimated) of single track | , . | , . | |for tunnel rights in queens borough, being | | | | , ft. (partly estimated) of single track | , . | , . | |for street rights on thirty-first and | | | | thirty-third streets, north and south of | | | | terminal | , . | , . | +-----------------------------------------------+------------+------------+ | in all, per annum | $ , . | $ , . | +===============================================+============+============+ if the route under thirty-first street be availed of, these amounts will be increased by $ , . for the first ten years, and by $ , for the next fifteen years. the amounts to be paid are to be readjusted at the end of twenty-five years; and thereafter at intervals of twenty-five years. if the city and the railroad company shall not agree upon the readjusted rates, they are to be determined by the supreme court of this state. _fifth._--the railroad to be entirely in tunnel except where it approaches the surface at its eastern terminal near thomson avenue, in queens borough. the uppermost part of the tunnel is to be at least nineteen feet below the surface of the street; but this limitation does not apply to the portions of thirty-first and thirty-third streets opposite the terminal station between seventh and ninth avenues, where the company may occupy the underground portions of the street under the roadway to within thirty inches of the surface, and under the sidewalks on thirty-first and thirty-third streets opposite to the station to within five feet of the surface, the company to properly care for sewers, water, gas and other pipes and underground structures lawfully in the street. _sixth._--the company to make good all damage done to property of the city by its construction work or operations, and to abutting owners all damage done through any fault or negligence of the company, or of any contractor or sub-contractor engaged upon its work of construction or operation. the tunnel company to keep thirty-first and thirty-third streets opposite the station well paved with smooth pavement and in thoroughly good condition. _seventh._--tunnel excavations to be done without disturbing the surface of the street, except in the portions of thirty-first and thirty-third streets, and seventh, eighth and ninth avenues in front of the terminal station, and except in queens borough, with the power to the rapid transit board, wherever conditions elsewhere make surface excavation necessary for efficient construction, to grant the right for such excavation, subject to conditions to be then prescribed by the board. the tracks are to be constructed of the most approved plan so as to avoid noise or tremor. all plans for, and the method of doing, the work are made subject to the approval of the rapid transit board. _eighth._--the motive power to be electricity, or such other power not involving combustion as may be approved by the board. _ninth._--the company to have no power to carry on merely local traffic, except with the approval of the board and for additional consideration to be paid the city. traffic is defined as local which begins and ends in the city within five miles of the terminal station on seventh and ninth avenues. _tenth._--the railroad to be diligently and skillfully operated, with due regard to the convenience of the traveling public. _eleventh._--the city to have a lien upon the franchise and real property of the company to secure the payment of rental. _twelfth._--the rights of the city to be enforceable by action, for specific performance, or mandamus, or otherwise. _thirteenth._--the company not to oppose the construction of any rapid transit railroad along or across the same routes which do not actually interfere with the authorized structures of the company. _fourteenth._--the city to have an ample right of inspection of the railroad, and to enter upon it for examination, supervision, or care of city property, or for other purposes. _fifteenth._--the company to be bound to maintain and strengthen all parts of its railways under streets or avenues so that the same shall support safely any structures superimposed or which may hereafter be superimposed thereon by the city or under public authority. _sixteenth._--the company to have the right to convey or mortgage the franchise, but every grantee, whether directly or under a mortgage, to assume the obligations already assumed by the railroad company and the railroad company not to be relieved of such obligations by the grant. this franchise was passed by the board of aldermen on december th and approved by the mayor on december d, . subsequently, an agreement, dated june st, , was entered into by the city of new york, the tunnel company, and the long island railroad company covering the construction of the sunnyside yard, which forms the eastern terminus of the line. in pursuance of this agreement, the map or plan of the city of new york was changed by discontinuing or closing portions of fifty streets or avenues, and by changing the grades of sixteen streets or avenues, in the borough of queens, and the portions of streets and avenues thus discontinued and closed, most of which were not opened for public use, were sold to the railroad companies. the agreement, however, reserved to the city permanent and perpetual underground rights and easements to maintain in a reasonable manner, not inconsistent with the construction and operation of the railroad facilities of the companies, its existing sewers, drains, and other sub-surface structures in, under, and through the lands within the lines of the discontinued portions of each of such streets and avenues, including the right to repair, rebuild, and enlarge the same, and to construct in a reasonable manner, not inconsistent with the construction and operation of the railroad facilities of the companies, such additional sewers or drains in, under, or through the lands as may be hereafter required by the city, together with the right to enter upon the premises from time to time as may be necessary for the purpose of inspecting, repairing, constructing, or rebuilding the sub-surface structures. the agreement required the companies to construct at their expense, four viaducts or bridges over their tracks and terminal development, three with roadways ft. wide, one with a roadway ft. wide, and each to have two sidewalks ft. wide, the work to include the paving of the roadways and sidewalks. the companies are further required to pay one-half the cost of the construction of the foundations, abutments, piers, superstructures, and approach of an additional viaduct or bridge over the sunnyside yard, to have a roadway not more than ft. wide and two sidewalks each ft. wide, and to grant the city of new york a perpetual easement for the continuance of the same in the location upon which it shall be constructed. the agreement further provides that the companies shall not injure the sewers or other substructures now existing or hereafter constructed under the streets and avenues, and, in case of injury, that they shall repair them or pay the cost thereof; that the viaducts shall be completed within the shortest time consistent with their safe and proper construction, and that during their construction temporary streets shall be provided for the accommodation of traffic. the companies are required to bear all the expense of changes of grade in the streets and avenues, except those made necessary by the construction of the viaduct or bridge to be paid for in part by the city; to indemnify the city against all liability for any and all damages which may accrue on account of any street which may be closed or the grades of which may be changed in pursuance of the agreement; to assume all liabilities by reason of the construction or operation of the railroads, or the construction of the viaducts, and to save the city harmless from any liability whatever, to either persons or property, by reason of the construction or operation of the railroads or the construction of the viaducts. the companies are also required to indemnify the city against and pay the cost of all alterations which may be required to the sewerage or drainage system or to any sub-surface structures and pipes laid in the streets or avenues on account of the construction and operation of the terminal, passenger yard, or freight yard of the companies, or on account of the changes in grades or street system. the companies are authorized, if they deem it necessary to the construction or to the efficient operation of the terminal passenger yard or freight yard, to depress, at their expense, any pipes or other sub-surface structures now under the surface of any of the portions of the streets or avenues discontinued or closed, or to elevate and carry the same upon any of the viaducts or bridges, the plans of such depression or elevation to be approved by the board of estimate and apportionment. all works within, upon, or over the public streets and avenues are subject to the supervision and inspection of the proper municipal officer or officers, under such regulations as he or they may determine and be authorized by law to impose; and the plans for the construction of viaducts or bridges are to be approved by the board of estimate and apportionment. the companies are required to cede to the city of new york perpetual easements for the right to continue and maintain the viaducts or bridges over the streets and avenues, sufficient for their control by the city for the purpose of police regulation and other control contemplated by the city ordinances for the case of streets or highways; reserving, however, the right to construct and maintain, at their own expense, such connections between the viaducts or bridges and their property as shall not interfere with the use of the viaducts or bridges for street purposes. the companies are also required to cede to the city, grade and curb, portions of five existing or proposed streets or avenues, and to pave portions of two other avenues. mr. a. j. cassatt, president of the pennsylvania railroad company, was president of the companies constituting the new york tunnel extension until his death on december th, , and mr. james mccrea, president of the pennsylvania railroad company, was elected his successor, and is now president of the pennsylvania tunnel and terminal railroad company. mr. samuel rea, second vice-president of the pennsylvania railroad company, has served as vice-president since the incorporation of the enterprise. mr. a. j. county has been assistant to the president since june th, , and prior thereto and from the incorporation of the tunnel enterprise served as secretary of the pennsylvania, new jersey and new york railroad company and as assistant secretary of the pennsylvania, new york and long island railroad company, which, as heretofore stated, constitute the pennsylvania tunnel and terminal railroad company. engineering organization. mr. rea, vice-president, has general charge of all matters involved in the designing and execution of the project. _the board of engineers._--before the beginning of the work, the management appointed a board of engineers which was instructed to examine into the new york tunnel extension project; to pass upon the practicability of the undertaking; to determine upon the best plans for carrying it out; to make a careful estimate of its cost; and, if the work was undertaken, to exercise general supervision over its construction. president cassatt's letter appointing the board contains the following further instructions: "you are requested to procure all additional information that may be needed, sparing neither time nor any necessary expense in doing so, for i am sure it is not necessary for me to say that, in view of the magnitude and great cost of the proposed construction, and of the novel engineering questions involved, your studies should be thorough and exhaustive, and should be based upon absolute knowledge of the conditions." the board was organized on january th, , when it held its first session, and continued in the performance of its duties until april th, , when it was dissolved, its work having been completed. the board held regular and special sessions to receive progress reports from the chief engineers in direct charge of construction, and to consider questions relating to the plans and details of the work submitted by its members or referred to it by the management. it then reported its conclusions to the vice-president for approval before the work was undertaken. the management earnestly impressed upon the board throughout the whole period of its labors, that the tunnel extension and facilities were to be designed and constructed without regarding cost as a governing factor, the main considerations being safety, durability, and proper accommodation of the traffic. no expenditure tending to insure these conditions was to be avoided. the board, when organized, was composed as follows: col. charles w. raymond, corps of engineers, u. s. army, chairman; messrs. gustav lindenthal, charles m. jacobs, alfred noble, and william h. brown. mr. george gibbs was appointed a member of the board on april th, . mr. lindenthal resigned on december th, , and mr. brown resigned on march st, . mr. rea and all the members of the board are members of the american society of civil engineers, and mr. noble is a past-president of the society. mr. william r. mead, of the firm of mckim, mead, and white, architects for the terminal station, was associated with the board for the consideration of architectural subjects. mr. robert h. groff, secretary of the company, was also secretary of the board until his resignation on january st, . mr. william couper was acting-secretary from april th, , to april th, . s. johannesson, assoc. m. am. soc. c. e., was engineer assistant to the chairman from december st, , to april th, . _division of the work._--for the purposes of actual construction, the line was divided into four parts: the meadows division, the north river division, the terminal station, and the east river division. a chief engineer appointed by the management had charge of the construction of each division. the chief engineers exercised full authority in the organization of the working forces, and in the general conduct and management of the work of construction on their respective divisions, in accordance with the plans for such work approved by the board of engineers and the management. architects were employed to design the terminal station building and superintend its erection; and structural engineers to design and erect steel structures and facilities, and carry on the work under the direction of a chief engineer of the company. committees, consisting principally of officers of the pennsylvania railroad company, co-operating with the regular engineering organization, were appointed to consider the operating features of the project, so that the experience of the pennsylvania railroad company's organization might be utilized in the work. [illustration: plate i.--pennsylvania tunnel and terminal railroad. map and profile. bergen hill tunnel, new jersey to long island shaft, borough of queens] description of the line. the following summary description of the various divisions of the line is intended to give a comprehensive idea of the general features of the project. full details will be given in succeeding papers. the line and its respective divisions are shown on plate i. _meadows division._--chief engineer until march st, , mr. william h. brown, chief engineer, pennsylvania railroad company, when he retired from active service with the latter company; since march st, , mr. alexander c. shand, chief engineer, pennsylvania railroad company. this division consists of an "interchange yard" at harrison, near newark, n. j., adjoining the tracks of the present new york division of the pennsylvania railroad, and a double-track railroad across the hackensack meadows to the west side of bergen hill, a distance of . miles. the construction is embankment and bridge work, including bridges across the pennsylvania, erie, and lackawanna railroads, and the hackensack river. _north river division._--chief engineer, mr. charles m. jacobs. this division commences at the west side of bergen hill and passes through the hill in two single-track rock tunnels to a large permanent shaft at weehawken, near the west shore of the north river, and thence eastward a distance of ft. to the weehawken shield-chamber. it then passes under the river through two cast-iron, concrete-lined, single-track tunnels, with outside diameters of ft., to a point under d street, near eleventh avenue, in new york city, and thence through two single-track tunnels of varying cross-section, partly constructed in cut-and-cover, to the east side of tenth avenue. it then passes into the station yard and terminates at the east building line of ninth avenue. the work included the station yard excavation and walls from tenth avenue to ninth avenue, and the retaining walls and temporary underpinning of ninth avenue. the aggregate length of the line in this division is . miles. _new york station and approaches._--mr. george gibbs, chief engineer of electric traction and station construction. the station and its approaches extend from the east line of tenth avenue eastward to points in d street and d street, respectively, ft. and ft. east of the west line of seventh avenue. this division included the construction of subways and bridges for the support of st and d streets and seventh, eighth, and ninth avenues, the station building between seventh and eighth avenues, the foundations for the post office to be erected west of eighth avenue, the service power-house in st street between seventh and eighth avenues, the power-house in long island city, the traction system, tracks, signals, and miscellaneous facilities required in the physical construction of the entire terminal railroad ready for operation. messrs. mckim, mead, and white were the architects for the station and messrs. westinghouse, church, kerr and company executed the structural engineering work, both in the station and for the support of the streets, as well as the construction of the subways. the station is of steel skeleton construction with masonry curtain walls, all supported by a system of columns extending to a rock foundation. this building covers two city blocks and one intersecting street, and has an area of about acres. it is ft. long, ft. wide, with an average height above the street of ft., and a maximum of ft. the main waiting-room is ft. long, ft. wide and ft. high. the concourse is ft. long and ft. wide. the level of the track system below the street surface varies from to ft., and is from to ft. below mean high water in the harbor, thereby necessitating the establishment of an elaborate system of drainage over the entire station yard area. access to the street is gained by elevators and stairways. to accelerate the loading and unloading of the trains, high platforms will be constructed in the station on a level with the floors of the cars, in order to avoid the use of car steps and increase the traffic capacity of the station. there will be standing-tracks at the station, and passenger platforms, providing , ft. of platform adjacent to passenger trains. within the station area, which from tenth avenue to the normal tunnel sections east of seventh avenue comprises acres, there will be a total of about miles of track. the service plant for the installation of machinery for lighting, heating, and ventilating the station, and for operating the interlocking system, is located in an independent building south of the station. the power-house to supply the electrical energy for the operation of the tunnel line and the long island railroad is situated on property in queens borough adjoining the present long island railroad station near the east river, and was constructed under the chief engineer of electric traction and station construction. as at present designed, the dimensions of the structure are ft. by ft., outside measurement. it can accommodate six generating units of , kw., the standard adopted for future work, and two of , kw. for lighting the tunnels. the ultimate capacity of this station when extended will be about , kw. _east river division._--chief engineer, mr. alfred noble. this division begins at the eastern limits of the new york station at a point in d street, ft. east of the west line of seventh avenue, and at a point in d street, ft. east of the west line of seventh avenue, and also includes the excavation work and retaining walls for the station site and yard, to the track level, westward to ninth avenue. it extends eastward from the station under d and d streets through tunnels partly three-track and partly so-called twin tunnels to second avenue; thence the line curves to the left under private property to permanent shafts a few feet east of first avenue. four single-track, cast-iron, concrete-lined tunnels, with outside diameters of ft., pass under the east river, and, after passing through permanent shafts near the bulkhead line, reach the surface in long island city from , to , ft. east of the east river. the tunnel portals are in sunnyside yard, which extends to woodside, the easterly end of the division, and the yard grading with its buildings and a number of city viaducts crossing it were executed under this division. the total length of the division is . miles. the total length of the entire line is . miles. there are . miles of single-track tube tunnels, and the average length of the tunnels between portals is . miles. [illustration: plate ii.--pennsylvania tunnel and terminal railroad. map and profile. harrison yard to bergen hill tunnel. meadow division july ] general considerations. details have been omitted from the foregoing description, as they can be treated better and more fully by the constructing engineers in succeeding papers. there are, however, some general considerations involved in the designing of the work, which may, perhaps, be referred to more conveniently in this introductory paper, and these will now receive attention. in all parts of the work problems were encountered requiring for their solution large expenditures and much engineering skill; but many of these difficulties had been frequently met in previous engineering experience, and the methods of overcoming them were well understood. thus, in the meadows division, a long and heavy embankment, part of which was on submerged meadow land, and many bridge foundations had to be constructed; in the bergen hill tunnels, very tough trap rock was encountered; in the tunnels under the city, the work was much complicated and its cost increased greatly by the necessity of caring for sewers, water and gas pipes, and the foundations of adjacent buildings; and many troublesome problems were met in the construction of the tunnels connecting the east river tunnels with the sunnyside yard. the novel features of the project, however, were the great tunnels extending the line under the north and east rivers. tunnels of the kind contemplated, to be used for heavy and rapid railroad traffic, had never been constructed through materials similar to those forming the beds of the north and east rivers. questions arising in connection with the design and method of construction of the tunnels will be considered later. here they are referred to only in their relation to the location and grades of the line, in which connection the conditions controlling their establishment were the most important elements. _location and grades._--it was desirable to make the tunnels between the bulkhead lines of the rivers as straight as possible, and it was necessary to place them at sufficient depth below the dredging plane of the war department (which in the north and east rivers is and ft. below mean low water, respectively) to insure them against possible injury from heavy anchors or sunken vessels. furthermore, they had to pass under the piers and bulkheads of manhattan at a depth sufficient to make it certain that they would not affect the stability of those structures. another consideration influencing the establishment of the depth of the tunnels below the bottoms of the rivers became important as soon as the method of construction by shields with compressed air was adopted, namely, the necessity of providing sufficient cover to guard, as far as possible, against blow-outs during construction. the tunnels under the city, connecting the sub-river tunnels with the terminal station, were located so as to give as favorable grades as possible. the provision of the franchise requiring the tops of the tunnels to be at least ft. below the street surface, which had been suggested by the company to permit of future subways, had no effect on their location, as other conditions required them to be at a greater depth. the line extending westward from bergen hill had to be established so as to give ample head-room at the numerous bridges over the railroads and highways which it crosses. eastward from the east river tunnels, the grades were established so as to rise as uniformly as possible to the level of the sunnyside yard. the general features of the line, as finally adopted and constructed, are as follows: the maximum grade west of the terminal station occurs on the new york side of the north river, and is % in the west-bound and . % in the east-bound tunnels. the ruling grades (for the ascending traffic) being . % in the west-bound and . % in the east-bound tunnels. in the tunnels east of the terminal station the ruling grade is . % for both east-bound and west-bound traffic. there is, however, descending with the traffic, a short section on a grade of . per cent. these grades would be objectionable with steam locomotives under a heavy traffic, but the development of the electric locomotive has rendered possible the operation of grades which would have formerly been considered prohibitive. from the junction with the pennsylvania railroad, near harrison, n. j., to woodside, long island, a distance of . miles, there is an average of . curves per mile; the line having a total curvature of degrees. the maximum curvature is degrees. [illustration: plate iii.--p. t. & t. r. r. east river division. sunnyside yard] _method of construction of sub-river tunnels._--the character of the material through which the tunnels were to be constructed differed greatly in the two rivers. the bed of the north river, at the level of the tunnels, consists of silt composed principally of clay, sand, and water, while that of the east river is formed of a great variety of materials, such as quicksand, sand, boulders, gravel, clay, and bed-rock. when the method of construction had to be decided there were no thoroughly satisfactory precedents to follow in the case of either river, although the gas tunnel under the east river, the partly constructed hudson tunnels under the north river, the st. clair tunnel under the st. clair river, the blackwall and several other tunnels under the thames river at london, supplied much useful information. the smaller tunnels for a lighter traffic, since so successfully constructed under the north and east rivers, had not then been completed. under these circumstances, it was the desire of the management that the board should receive and consider proposed methods of construction from all available sources; and during the first year of its labors much of its time was devoted to the examination and discussion of projects submitted for its consideration by engineers and practical builders, some of these projects having decided merit. most of the methods proposed involved temporary structures, or the use of floating plant, in the navigable channels of the river. this was objectionable in view of the resulting obstruction to the enormous river traffic. after full consideration of the subject, it was decided to adopt the shield method with compressed air for the construction of the tunnels under both rivers, this being the only method recommended by the chief engineers, and having the great advantage of conducting all operations below the bottom of the river, thus avoiding obstruction of the channel. experience has shown, as was anticipated, that it is much more difficult to construct tunnels in such material as occurs in the east river and on the new jersey side of the north river, than in more homogeneous material such as is found in the greater part of the north river. during the progress of construction under the east river, there were frequent blow-outs through fissures opened in the river-bed, and the bottom of the river over the tunnel had to be blanketed continuously with clay, to check the flow of the escaping air. in view of the serious difficulties which it was thought might be encountered in the application of the shield method to the east river work, other methods for the execution of this part of the project received special consideration, one of the methods considered being the freezing process. it was proposed to drive a small pilot tunnel and freeze the ground for a sufficient distance around it by circulating brine through a system of pipes established in the tunnel. the pilot tunnel was then to be removed and the full-sized tunnel was to be excavated in the frozen material and its lining placed in position. by this means, it was intended to avoid the danger incident to the use of compressed air in material of greatly varying character. this method contained too many elements of uncertainty to justify its adoption; but as the management considered it desirable to have, if possible, an alternative method, an extended experiment was made with the freezing process. a pilot tunnel, ft. in. in diameter, was driven in the bed of the east river for a distance of ft., circulating pipes were established in it, and brine at a very low temperature was passed through the pipes until the ground was frozen for a distance of about . ft. around the tunnel. observations to determine the rate of cooling and other important points connected with the process were carefully made. when it was found that the construction of the tunnels was progressing satisfactorily by the shield method, and that so much time was required to freeze the material that the freezing process could not be used to advantage in this particular case, the experiment was discontinued. _design of the sub-river tunnels._--the sub-river tunnels consist of a circular cast-iron shell, of the segmental, bolted type, having an outside diameter of ft., lined with concrete having a normal thickness of ft. from the outside of the shell. through each plate of the shell there is a small hole, closed with a screw plug, through which grout may be forced into the surrounding material. each tunnel contains a single track. a concrete bench, the upper surface of which is ft. below the axis of the tunnel, is placed on each side of the track, the distance between benches being ft. in. these benches contain ducts for carrying electric cables. the main reason for adopting single-track tunnels instead of a larger tunnel containing two tracks was to avoid the danger of accidents due to the obstruction of both tracks by derailment or otherwise. the tunnels are made just large enough to allow the passage of a train with perfect safety, as it was believed that with such an arrangement thorough ventilation would be secured by the motion of the trains. experience seems to justify this assumption, but, in order to assure thorough ventilation under unusual conditions, such as the stoppage of trains in the tunnels, a complete ventilating plant will be provided for each tunnel. the rapidity and safety of construction were increased by making the tunnel as small as possible, one of the difficulties in the shield method of construction being the difference in hydrostatic pressure between the top and bottom of the shield, which increases with the diameter of the tunnel. the concrete lining was introduced to insure the permanency of the structure, strengthen it from outward pressure and guard it against injury from accidents which might occur in the tunnel. the side concrete benches were suggested by mr. cassatt, president, to confine the trains to the center of the tunnels in case of derailment, and to furnish sidewalks on each side of the trains so as to obviate the necessity of walking on the track. refuge niches are constructed in the side benches of the tunnels. manholes, splicing chambers, pump chambers, and other features for the handling of the electric cables and drainage, are established at intervals. at points where unusual stresses were anticipated, as for instance where the tunnels pass from rock to soft ground, the shell was composed of steel instead of cast-iron plates. in the north river tunnels the concrete lining in the invert and in the arch was reinforced by longitudinal steel bars, but these were not introduced in the east river tunnels. other details connected with the structures, including the drainage, lighting, ventilation, signaling, and electrification systems, will be given in succeeding papers. _stability of the sub-river tunnels._--one of the most important questions connected with the design of these tunnels was their probable stability under the long-continued action of a heavy and rapid railroad traffic. the tunnels are lighter than the materials which they displace even when the weight of the heavy live load is included. in the east river the character of the material seemed to justify the conclusion that the tunnels would not be displaced even under the action of the live load. in the north river, however, the tunnels are enveloped by a soft silt and it was at first apprehended that some system of supports would be advisable to carry the heavy traffic and insure the tunnels against displacement under its action. to meet this contingency, which was then believed to be a very serious one, it was proposed to sink cast-iron screw-piles through the bottom of each tunnel into and through the underlying silt until satisfactory bearing material was reached. the pile supports were worked out in sufficient detail to be embraced in the contract for the construction of these tunnels, with provision, however, for omitting them should it be determined subsequently that their use was undesirable. the contract plans contained provisions for sliding joints where the piles pass through the tunnel floor, so that the live load might be carried directly to the pile heads by a system of girders, and also for attaching the piles directly to the tunnel, the two plans being alternatives. investigations, made during the progress of the work to determine the physical character of the silt and its action on the tunnels, suggested the possibility that the use of pile supports might be inadvisable. this view was confirmed by actual experience in the operation of the tunnels of the hudson companies between hoboken, n. j., and morton street, manhattan, which were opened to traffic in february, . the stability of these tunnels under traffic gave further assurance that supports were unnecessary under the north river tunnels of the pennsylvania railroad company, and they were therefore dispensed with. _cross-passages between the tunnels._--the bergen hill tunnels, the land portions of the north river tunnels and the tunnels under manhattan are connected by cross-passages at intervals varying from to ft. as it was the desire of the management to provide every arrangement possible to insure the safety of its passengers and employees and also to provide for the convenience of inspection, the question of establishing cross-passages between the tunnels under the rivers was given most careful consideration. the conclusion was finally reached that such passages as it was possible to construct between these tunnels might increase instead of diminish the danger in case of accident. no more cross-passages have therefore been constructed in the sub-river sections, except in the east river, where there is a cross-passage and pump chamber combined between each pair of tunnels about ft. from the manhattan bulkhead line. probable results of the improvements. in preceding pages reference has been made to the general objects of the improvements included in the project of the pennsylvania railroad company for the new york district. while it is impossible, in this introductory paper, to analyze fully the transportation problem at new york, it seems desirable to indicate briefly some of the more obvious effects which the improvements may be expected to produce upon the distribution and handling of traffic. new york city owes its position as the business metropolis of the country mainly to its magnificent harbor and the extensive waterfronts on its deep, wide rivers, which furnish unrivaled facilities, at a short distance from the sea, for foreign and domestic water-borne commerce, its foreign commerce being about half the total for the whole country. the water-transportation facilities of the port and its tributaries, therefore, have always been guarded with jealous care, not only by the local commercial interests but also by the general government. during recent years, however, the population of the metropolitan district has increased so enormously that new york is now the greatest terminal passenger and freight traffic center in the country; and in manufactures it ranks first among american cities. the new commercial interests thus created are of at least equal importance with those of the water-borne commerce, although their existence and development are largely the result of the water facilities of the port. the local passenger and freight traffic of the pennsylvania and of other railroads reaching the west shore of the north river is conducted by car-floats and ferry-boats which deliver their loads at piers on the manhattan waterfront and elsewhere in the harbor. these boats obstruct and endanger the free navigation of the channels and occupy space along the waterfront greatly needed for the accommodation of the long-distance water-borne commerce, especially on the north river. in the east river the importance of ferry-boats as a means of traffic distribution has already been greatly reduced by the construction of bridges and tunnels which provide for the greater part of the passenger and vehicular traffic. the north river, however, by reason of its greater width and the comparative slowness of its currents, is by far the more important waterway for the use of ocean-going vessels of the larger classes. in this river the conditions for the construction of bridges, within the limits of commercial convenience, seem to be practically prohibitory. tunnels, for the transportation of passengers and the diversion of the freight traffic from the inner waters of the harbor, are apparently the only available means of relief. when the new line is in operation, a very large part of the new york passenger traffic of the pennsylvania railroad will be carried to the new york station at seventh avenue and d street and the rest will go to cortlandt street through the hudson company's tunnels. thus a large portion of the pennsylvania passenger ferry traffic, which amounts to more than , passengers daily, will be practically eliminated from the water-transportation problem. in addition, a large part of the long island railroad's passengers will use the station at seventh avenue and d street, and its ferry traffic will be reduced accordingly. the new arrangements for the transfer of freight from greenville to bay ridge will relieve the inner waters of the harbor of a large volume of obstructive car-float traffic. there appears to be no reason why this traffic should not be eventually conducted through tunnels under the outer harbor, should future transportation conditions justify the enormous cost of such structures. it is to be remarked that while these new arrangements greatly reduce the passenger and freight water transportation, they have no effect on the large vehicular traffic across the north river which must continue to be conducted by ferries until it can be otherwise provided for. as long as these conditions exist, ferry-boats must be used in large numbers and continue to obstruct the north river. this difficulty probably cannot be overcome by the construction of bridges, as in the case of the east river, but it does not seem too much to expect that, eventually, tunnels to provide for the vehicular traffic, like the blackwall tunnel under the thames, will be established under the north river. it would be interesting to estimate the increase in railroad traffic capacity resulting from these improvements, but the data required for this purpose are not available. some idea of the increase in passenger traffic capacity resulting from the establishment of the tunnel line may be obtained by comparing the proposed daily train-movements for the new station with the train-movements at other important railroad stations. the daily train-movements of six such stations are given in the following table: total trains movement in and out at for hours. maximum hour. jersey city broad street station, philadelphia union station, st. louis south terminal station, boston grand central station, new york pennsylvania station, new york[b] footnotes: [footnote b: proposed train service when station is opened, the ultimate capacity of the station being in excess of , trains per day.] the freight capacity of the pennsylvania system at new york has been greatly enlarged by the construction of the greenville yard and the facilities connected therewith, but it is impossible to estimate the amount of this increase. however, it is worthy of remark that, during the period from to , the freight traffic density on the directly-operated lines of the pennsylvania railroad company increased from , , to , , ton-miles per mile of road, a growth of nearly per cent. doubtless the improved freight facilities of the new york district had a large influence in the development of this increase. one of the most interesting points connected with this development of traffic facilities is its influence on the relative distribution of population in the different parts of the metropolitan district. in the population per acre of the different divisions of greater new york was reported as follows: manhattan, ; brooklyn, ; bronx, ; queens, ; richmond, . the effect of new lines connecting some of these districts, and sections of new jersey not far from the north river, with the business center of the city will undoubtedly be to increase greatly their population-density. it does not seem probable that the population-density of manhattan will be sensibly reduced by these improvements, for they stimulate the increase of population, and apparently no increase of transportation facilities can keep up with the growth of the city. the population of a great commercial city must be congested near the business center. this is a necessary condition of its existence. all that can be done to meet this condition is to provide all possible facilities for moving the people into and out of the business districts and within its limits. during recent years the business population of the lower part of the borough of manhattan has become greatly congested. very high buildings, providing business accommodations for large numbers of people, have been constructed, and these people must move to and from their working places at about the same times, that is, at the "rush hours" in the morning and afternoon, at the beginning and ending of the working day. every effort has been made to provide for this immense and rapidly increasing local passenger traffic, by the construction of surface, elevated, and subterranean railways; but the demand for transportation has increased much faster than the facilities can be provided, and it is evident that the limit of down-town passenger traffic facilities has been very nearly reached. apparently, the only remedy for these conditions is the movement of business and the people transacting it up-town or to the boroughs of brooklyn and queens, which are now readily accessible by tunnels and subways. this movement, of course, is resisted by the great real estate and money interests centered in the lower part of the city, but, notwithstanding this resistance, the improvement has commenced and has rapidly advanced. the great retail houses are being established above d street; the banks and brokers' offices are rapidly appearing around the new business center of the city. the facilities afforded by the telephone and the subway for communication with the money center have doubtless greatly promoted this up-town movement. when the pennsylvania tunnel extension is in operation, the easiest and quickest way for the passenger to reach the city from newark will bring him into the pennsylvania station at seventh avenue and d street. the schedule fast time from newark to the new york cortlandt street station is now min. this may be reduced to about min. by the use of the hudson company's tunnels, and while this involves inconvenience in changing transportation at jersey city, yet it brings the traveler three blocks nearer broadway. the time from newark to the pennsylvania station will be about min., and the trip will be made without change of transportation, so that, undoubtedly, by far the greater part of the pennsylvania's passenger traffic desiring to reach the shopping and hotel center of the city will go to the new up-town station. the effect of the tunnel extension in increasing the volume and rapidity of the up-town movement and the real estate values will be very great; indeed, its influence is already apparent, although the line is not yet opened for traffic. with the extension of the present subway down town on the west side with direct connections to brooklyn, and up town from d street to the bronx, with connections to permit convenient transfers between these two straightaway subways--one on the east side and the other on the west side of manhattan--the pennsylvania station will become a great center for receiving and distributing passenger traffic between all the boroughs of the city and outlying points. the new post office to be established adjacent to the terminal station will also greatly assist in accelerating the up-town movement. in concluding this account of the new york tunnel extension project, the writer desires to pay a tribute of admiration and respect to the memory of the late a. j. cassatt, president of the pennsylvania railroad company, to whom the conception, design, and execution of the project are mainly due. his education and experience as a civil engineer, his thorough knowledge of all the details of railroad construction, operation, and management, gained by long and varied service, the directness, clearness, and strength of his mind, and his great executive ability, placed him at the head of the railroad men of the country. in the consideration of great problems, whether of transportation, finance, commerce, or political economy, he was almost unequaled, owing to the breadth, originality, and decisiveness of his character; yet his manner to his subordinates was so direct and simple that he seemed unconscious of his own superiority. great as it is, the new york plan of improvement is only one item in a far-reaching scheme of development which became the policy of the pennsylvania railroad company through mr. cassatt's advice and influence, yet his strongest interest was doubtless centered in the new york works. it is the sincere regret of all connected with the design and execution of the project that he did not live to see its completion. footnotes: [footnote a: brigadier-general, u. s. army, _retired_; chairman, board of engineers, pennsylvania tunnel and terminal r. r. co.] transcriber's notes: italic text is denoted by _underscores_. notation for whole and fractional part is - / * * * * * senate...... ......no. . ======================================== report on the hoosac tunnel and troy and greenfield railroad, by the joint standing committee of . ----- boston: wright & potter, state printers, no. spring lane. . commonwealth of massachusetts. hon. joseph a. pond, _president of the senate_. sir:--i herewith transmit to the legislature the report of the joint standing committee of on the hoosac tunnel and troy and greenfield railroad. i am very respectfully your obedient servant, tappan wentworth, _chairman_. report. the joint standing committee of on the hoosac tunnel and the troy and greenfield railroad, authorized to visit the tunnel and railroad, examine into the condition and progress of the work, and to report fully the result of such examination respectfully report: that since the adjournment of the legislature the committee in a body visited the tunnel and railroad in june, and again in october, and they continued their examination of the condition and progress of the work by sub-committees in the months of july, august, september, november and december; (one of the examinations being exclusively devoted to the operations on the railroad which were commenced late in october;) the others to the tunnel and the various structures and mechanical operations connected therewith, including an examination of the existing contracts, and an inquiry into the general organization adopted to carry out the laws and purposes of the state in regard to the enterprise. the committee have also examined the records and the doings of the directors of the troy and greenfield railroad from the organization of the corporation until the surrender of the railroad to the state, and have made extracts from the records to show the financial condition of the corporation, its dealings with the contractors for constructing the road and tunnel, and also the embarrassed condition of the contractors and corporation from to , which finally led to the practical abandonment of the contract on the part of messrs. h. haupt & company, and the surrender of the road to the state under the mortgages which had been given to secure the loan advanced by the commonwealth in aid of the road and tunnel. these extracts from the records, with extracts from some of the laws passed upon the subject of the railroad and tunnel, together with remarks of the committee upon the legislation of the state, the doings of the directors, and their efforts and those of the contractors to prosecute the enterprise being too long for the body of this report, will be found in the appendix at a. and a synopsis of the action and condition of the corporation at the time of, and previous to the surrender of the road, and the relation of the contractors to the corporation and to the state, will be stated before entering upon the particular description of the condition and progress of the work the present year, as observed by the committee. the charter of the troy and greenfield railroad was granted in , authorizing the construction of a railroad from a "point on the vermont and massachusetts railroad, at or near greenfield," to the line of the states of new york or vermont, to connect with any railroad that might be constructed from or near the city of troy in new york. its capital stock was limited to $ , , . authority was given in the charter to contract with any contiguous railroad leading from either of the above-named states, for the use of the same or any part thereof, or for operating the two roads conjointly, or for hiring such other railroad, or for letting their own railroad to the owners of any other road which should compose a part of the railroad line between troy and boston, of which the troy and greenfield railroad should be a part. the corporation was organized june , . april , , the directors voted an assessment of three per cent. upon its capital stock, and this assessment was the only one that was substantially collected, and on the first day of october, in the same year, they voted to put the construction of the road under contract as soon as sufficient subscription should be obtained therefore, commencing at pownal, vermont, and greenfield. in january, , $ , . had been received into the treasury, and $ , . had been expended with the approbation of the president of the corporation, leaving in the treasurer's hand $ . . sundry assessments was voted from time to, time, the last vote being in may, , amounting in all to per cent. upon the subscriptions, but they were rescinded in july, , and a new series of assessments were afterwards made which the committee understand were as unproductive of beneficial results as were the former, upon which only partial payments had been made by a portion of the subscribers. a contract for constructing the road was made with messrs. gilman and carpenter in october, . at the close of the year , stock to the amount of $ , had been subscribed, of which $ , was payable in land damages, and $ , was taken by the contractors. at this period in the history of the corporation, with $ , of available cash subscription, of which three per cent. had been paid, the corporation applied to the state for aid by a loan to enable it to prosecute the enterprise it had assumed, and this application was continued without success until , when the legislature passed the act authorizing a loan of $ , , , upon conditions which are particularly set forth in the loan act, (see appendix a and b,) which, modified by subsequent legislation, discloses the policy of the state in granting its assistance to the undertaking. it is proper to state, that at the time this loan was granted, there was no prospect of opening this line of travel by individual efforts, and the amount of the loan, taking into consideration the then assumed estimates of its probable cost, shows that the state assumed to defray the cost of an enterprise to the completion of which available individual means had proved inadequate. in , a contract for the construction of the road and tunnel was made with e. w. serrell. the capital stock of the corporation was fixed at $ , , . this contract was changed two or three times, and finally ended in one executed by h. haupt and henry cartwright. for an account of these changes, and of the votes and transactions of the directors and the contractors, reference is made to appendix a, where the same will be found in detail. upon a careful examination of these votes and transactions, the committee come to the conclusion that the financial embarrassments of the corporation from the year , when the first contract with e. w. serrell was made to the time of the suspension of the works under the last contract with h. haupt & co., are apparent. and it is also apparent that during the same time, the contractors assumed, to a very great extent, the control and responsibility of the enterprise. under the first contract, and on the day of its acceptance, the direction of the engineering operations within the tunnel was left with the contractor; excepting measuring for estimates and the final acceptance of the work; and on his subscribing $ , to the capital stock, $ , (less the new subscriptions,) was added to the contract prices for the work. under the second contract with serrell, haupt & co., the directors voted to substitute bonds for stock in payment of the work until , feet of the tunnel was completed, and to pay the discounts and losses to which the contractors might be required to submit, not exceeding fifteen per cent. per annum; and also, to issue to the contractors bonds to the amount of $ , in addition to payments. said bonds were to be sold or pledged by haupt & co., to enable them to raise means to carry on their operations under the contract. on the dissolution of the firm of serrell, haupt & co., in july , serrell resigned his office as director and was chosen consulting engineer. at the same time, w. a. galbraith, one of the contractors in the following contract, was chosen a director. thereupon a new contract was made with h. haupt, w. a. galbraith, c. b. duncan and henry cartwright. under this contract the estimates were to be made by the company's engineer. in july, , the records show that no payments had been made the contractors for more than a year, and that the work could be carried on only by the continued efforts and personal credit of the contractors. in february, , the contract was again changed, and messrs. haupt and cartwright engaged with the corporation to complete the road and tunnel. at this time, the records show that no payments had been made under the previous contracts "for more than two years; that the work could only be carried on by the continued efforts, increased expenditures, and personal credit of the contractors." by a provision of this contract, any revenue arising from the use of the road, or any portion of it, was assigned to the contractors until their claims upon the company were adjusted; and the payment of all the company's debts was to be deferred until that of the contractors was satisfied; and haupt & co. agreed to maintain the organization of the corporation, pay its bills for printing, and advance therefore a sum not less than $ , . the same year the rensselaer iron company was allowed a lien on the iron delivered to the contractors until the same was paid for. in , h. haupt relinquished his pecuniary interest in the contract, and was appointed chief engineer of the corporation. (see appendix a, page .) these transactions in which the contractors participated, (one of whom was on the board of directors,) show conclusively that they were fully apprized of the condition of the corporation, from the date of their first connection with the work to the time of its "suspension," no claim during the whole period having been made by them against the commonwealth for any work done for the corporation. the existence of the mortgages to the state were of course well known to the contractors. they were given in pursuance of laws passed by the legislature, and for security of the payments received by the contractors for their services. the right of the commonwealth to take possession of the railroad under the mortgages, must have been well understood. further, the corporation, in surrendering the road to the state, did no injury to the contractors, for the act of surrender did not take place until after the contractors had suspended work upon both road and tunnel, and practically abandoned the enterprise; thus leaving to the state the alternative, either to take possession of the work and complete the road and tunnel, or to abandon it; and, in addition to the loss of the advances already made, forego the anticipated benefits of an additional avenue for western traffic. the treasurer's books do not show any settlement between haupt and company and the corporation. the account standing upon the ledger shows a large balance against the contractors; but the committee are informed that subsequent to may , , a settlement was made upon the basis of mr. stevenson's report (see appendix a,) and that mr. haupt received, in conformity with the contract of h. haupt & co. with the troy and greenfield corporation, payment for all labor done and material furnished by said h. haupt & co., for the corporation, and that all matters between the parties have been adjusted. although the accounts between the contractors and the corporation are understood to be settled, it may be interesting to examine the account of the commonwealth with the enterprise and compare the value of the work done by the contractors at the time of its abandonment by them, with the payments made to them therefore, from the treasury of the state. the amount paid from the state treasury for work and materials upon the tunnel, $ , amount paid upon the road west of the tunnel, , amount paid upon the road east of the tunnel, , ----------- $ , amount earned by contractors under the contract upon the tunnel, $ , amount earned by contractors under the contract, upon the road west of tunnel, , amount earned by contractors under the contract, upon the road east of tunnel, including temporary work, , ----------- , ----------- $ , overpayment in reckoning sterling exchange, say, , ----------- overpayment when the work stopped in july, , $ , further payments made upon the work by the state from july to january , , ----------- total amount paid more than earned, $ , from the foregoing statement it appears that the contractors with the troy and greenfield railroad corporation, have received from the state, three hundred and nineteen thousand nine hundred and thirty-six dollars and eighty-two cents more than the value of the work which the corporation surrendered under the mortgage, and that the state has lost that amount of money in its efforts to assist in the construction of the work. it is proper to add as the judgment of the very intelligent chairman of the commissioners (mr. j. w. brooks,) from whose statement to the committee the foregoing figures are taken, that the loss to the state in the transaction by the failure of messrs. b. haupt & co., to perform their contract in a proper manner, will reach the sum of three hundred and fifty thousand dollars. (see statement, appendix c.) the commonwealth having taken possession of the road and tunnel, and by the legislation of and undertaken their construction with the free consent of the corporation, the directors by an appropriate vote, expressed their concurrence with the proceeding, and their reliance upon the "good faith of the legislature" to complete the enterprise which had exhausted the resources of its immediate projectors. the last act of the corporation, as appears by the records, was the choice of officers in august, , when alvah crocker was chosen president and wendell t. davis, clerk and treasurer. description of the tunnel. the tunnel enters the eastern side of the hoosac mountain, in the town of florida, a few rods from the right bank of the deerfield river. the eastern summit of the mountain is , feet above tide-water, , feet above the deerfield river, , feet above the grade of the railroad, and is distant from the east portal of the tunnel , feet. the western summit is , feet above tide-water , feet above the hoosac river, , feet above the grade of the railroad, and , feet distant from the west portal. each portal of the tunnel is feet above tide-water. the summits are - / miles distant from each other, and the valley between them at its lowest depression is feet above the grade of the railroad. the length of the tunnel, from the east end to the west end, as commenced by mr. haupt, is - / miles. its base is, at the east end, feet above the deerfield river, and at the west end, feet above the hoosac river. its grade, from the east end to the central shaft, is feet per mile; from the west end to west shaft, - / feet per mile; and from the west shaft towards the central shaft, - / feet per mile. these grades are calculated to allow the free passage of water from the centre. should the quantity of water found in the tunnel render feasible a reduction of this grade, a change is contemplated. [illustration: profile of the hoosac mountains] the dimensions of the tunnel areas follows: the rock cutting is feet high and feet wide. the brick-work is feet high and feet wide. the bottom of the tunnel will contain a culvert three feet deep at the centre. through this culvert the water from the tunnel is to be discharged. it now receives, in addition to the water accumulating in the tunnel, a -inch pipe, to carry air at a low pressure for ventilation; an -inch pipe to carry air for driving the drilling machines; and a -inch pipe for carrying water for use in the holes which are being drilled. should it be found advisable to use gas in carrying on the work, provision is made for a -inch pipe to carry the gas from the place of manufacture. the track is to be placed - / feet above the bottom of the rock tunnel, and - / feet above the bottom, where lined with brick. the distance by the highway, from the town of north adams, or from the west end to the east end of the tunnel, is about nine miles. from the first named points to the central shaft is about five miles, and from the central shaft to the east end the distance is six miles. the time necessary to travel from the west end to the east end, is two hours. loaded teams from either end to the other perform the distance and return in a day. _organization of the forces employed in the construction of the hoosac tunnel, june, ._ chief engineer thomas doane, salary, $ , two assistant engineers, salary each, , one " " " , one " " " [the assistants were assigned to different points upon the work.] one messenger, one man in the stable, paul hill, superintendent, salary, , one clerk, , one master mechanic, , one mechanical draftsman, , one pattern maker, _for materials and supplies:_ one cashier and paymaster, $ , one purchasing agent, , one freight clerk and assistant paymaster, , one store-keeper at east end, , one assistant store-keeper at east end, one store-keeper at west end, , one assistant store-keeper at west end, one helper for do. at west end, one store-keeper at central shaft, the above were contained on the engineer's pay-roll. since the first visit of the committee to the tunnel, many important changes have been made in the force above mentioned, to wit: the salary of the chief engineer was reduced to $ , , he to provide his transportation to various points upon the work. one of the assistant engineers resigned and retired, and the office of two of them has been abolished. the salary of the superintendent has been increased to $ , . the office of freight clerk has been abolished, and its duties transferred to that of paymaster and cashier. the salaries of store-keepers and their assistants were not a charge to the state, but were paid from the profit of their respective stores. at the commencement of the work, it was deemed necessary to provide stores at the three points where the operations were carried on, to supply the workmen readily with necessaries, so that no time might be lost by them in the important duty of making provision for their families. but in the present state of the enterprise, it is probable that private individuals would readily establish such stores, and relieve the state from a duty which, although it involved no pecuniary charge, diverted to some extent the attention of officers from their more legitimate avocations. foremen and others under the superintendent. _at west end._ one foreman of labor, $ . per day " of brickyard, . " " " of carpenters, . " " one time-keeper, . " " _west shaft._ one captain, $ . per day. two statisticians, who keep an account of articles delivered to the workmen, and also perform the electrical firing, . " " _central shaft._ one captain, $ . per day. one time-keeper--acting statistician, . " " _east end._ one time-keeper, $ . per day. one statistician, . " " one " . " " one foreman of masons at the east end, and inspector of do. at west end, . " " one foreman of carpenters, . " " of this list the foreman of the brickyard is a temporary appointment. the foreman of carpenters at the west end has finished his work and retired. the foreman of masons was discharged by the commissioners, and has entered into the employ of mr. farren at the west end. there are nine foremen of the heading gangs, two of whom have $ per month, and the remainder $ . per day. the heading gangs consist of eleven drillers each, including the foreman, and from three to five rockmen for removing stone. they work by shifts of eight hours, relieving each other at a. m., p. m., and , midnight. the blasts are made about the time of relief. the men working on the enlargement under private contractors make two shifts a day, each shift working ten hours. the committee made a special examination of the number of men employed under the engineer and superintendent, with a view of considering whether the force actually engaged was necessary to an economical prosecution of the enterprise, intending to suggest any reform that might occur to them as essential; but learning that the engineer would in the course of the year make some reduction in the number of the men as well as of the teams employed upon the work, the committee deferred taking up the subject until the anticipated reductions should have been made. and now understanding that the commissioners have the whole matter under consideration, and that they have already to some extent, acted thereon, the committee for reasons that would be obvious, withhold any recommendations or remarks upon this point. system of operations. the general superintendence of the labor on the work is vested in mr. hill. the reports are made to the engineer. the captains in the tunnel report weekly the proceedings of each day under the following heads, as follows:-- number of days' work. of holes drilled. of inches of holes drilled. of drills dulled. of pounds of powder used. of feet of fuse used. of sheets of paper used. of pounds of soap used. of pounds of candles used. of quarts of oil used. of lamps used. of pounds of wicking used. the captain at the shafts four times a month reports,-- the days' work of the engine-men. the revolutions of the engine. number of pounds of coal used. of feet of wood used. of gallons of sperm oil used. of gallons of kerosene oil used. of pounds of tallow used. of pounds of waste used. of pounds of tar used. of cages raised. of cars of stone raised. size of pump-plunger used. length of stroke. number of strokes. of gallons of water raised. of boilers in use. the materials furnished for the construction of the work are charged in their distribution to twenty-three accounts, as will be seen by the tabular statement of its cost. requisitions for materials are signed by the immediate overseer, captain or foreman; they are handed to the superintendent for approval, and by him forwarded to the engineer. if the requisition is approved by both, the materials are ordered, and when furnished the applicant signs upon a duplicate his receipt for the same. this course is pursued as well for materials taken from the state lands as for those purchased. suitable blanks for returns, requisitions, &c., are furnished to the several points, and the evidence of all the transactions is preserved in the office of the engineer. in addition to the above, a return of all material broken, or laid aside, is made to the engineer, at whose office a substantial account of all materials on hand, either in use, or out of use, may be found. the organization of the working force, and the mode adopted for supplies and expenditures at the various points, appear well adapted to an efficient and economical prosecution of the enterprise. divisions of the work. _east end._ _deerfield dam._--this structure is completed. flashboards to be used in low stages of water may have to be occasionally renewed. the canal is finished as far as wheelpit no. . the machine-shop is about feet long, and feet wide. it has three turbine wheels. a fourth wheel is designed, but is not required at the present time, and the pit to receive it is not completed. in the basement of the machine-shop are two compressors. the first was put in january, . it has four cylinders inches in diameter, and inches stroke. this compressor is used to drive the drills, and furnish air for the blacksmith shop. the second compressor was put in some time in october. it has four cylinders inches in diameter, and inches stroke, and is used for ventilation one-fourth of the time, two hours after each blast, viz., from to , a. m., from to , p. m., and from to , a. m. the compressors work satisfactorily. the loss of power in the transmission of air from the machine-shop to the drills, a distance of , feet, being hardly perceptible. in addition to the compressors, there is in the machine-shop the following machinery, viz.: three lathes, one of them worked by hand; a drilling machine; a planer; a bolt-cutting machine and a saw-table. sixty horse-power is required to carry the machine-drills, the machines in the shop, and to furnish air for the blacksmith shop. when the large compressor is used, additional horse-power is required. a circular saw at the east end of the machine shop, is occasionally used, driven by power derived from the turbine wheels. the blacksmith shop, near the entrance of the tunnel, contains three forges. the hand-drills are made, and, together with the machine drills, sharpened at this shop. the ordinary repairs of the drilling machines are done in the machine shop. new parts of the same are furnished from fitchburg. the heading in the tunnel at this end when driven by hand was about feet wide by feet high. when driven by the machines it is feet wide and feet high. its location is in the centre of the tunnel, - / feet above subgrade, and - / feet above the road bed. the force employed at this point in july last was-- mechanics in iron, engine-men, masons, manual labor, engine and compressor men, including firemen, carpenters, blacksmiths and helpers, statisticians, runners of machine-drills, sawyer, manual laborers, --- total in july, the first day of november there were employed here men. there are at this point, besides the shops and saw mill above mentioned, small offices, boarding-house, carpenters' shops, powder-houses, temporary blacksmith's shop, temporary horse-stable, sheds, engine-house, barn, instrumental station-house (all used by the state,) and cottages; first-class shanties, common shanties, temporary shanties, store under school-room; with cottage, old store and shanties, built by h. haupt & company, which are rented. the cost of the shanties at the east end, excluding the deerfield dam, was, in july, , . . . . . . . $ , in november, , . . . . . . . , the rents at the east end received by the state from shanties are, . . . . . . . , per annum. all rents are collected monthly. a resident engineer was stationed at the east end in charge of the work. the progress of the excavations at the east end heading for the year ending december, , has been feet; at the rate of . per month. the progress during the six months ending may, , was feet; an average per month of feet inches. one week was lost in june in introducing the machine-drills, in consequence of which the progress that month was reduced to feet inches. during the five months ending november , the progress has been - / feet; being an average of . feet per month. it will be seen by the table, that in july, the first month after the introduction of the drill machines, the progress attained was only . feet. as the men became better acquainted with them, the progress was increased to feet in august, and in september it rose to . , having nearly attained the average progress of the six months preceding their introduction. had there been an adequate supply, there can be little doubt that the progress would have continued to increase, and would have shown the superiority of the machine-drill over hand-labor; but the supply fell off, and the progress in october was reduced to feet and inches. _table showing the progress at east end heading, from november , , to january , ._ =========================================== | distance from | progress. date. | portal. | ----------------+---------------+---------- nov. , , | , . | dec. , , | , . | . jan. , , | . . | . feb. , , | , . | . mar. , , | , . | . april, , , | , . | . may , , | , . | . june , , | , . | . july , , | , . | . aug. , , | , . | . sept. , , | , . | . oct. , , | , . | . nov. , , | , . | . dec. , , | , . | . =========================================== the central shaft. there is at this point, used by the state in the prosecution of the work, the shaft-building, a carpenter's shop, a blacksmith's shop, a saw-mill, powder-house, gas-house, ash-house, wood-shed, and a barn; and in connection with the work, a store, a boarding-house, the thacher farm-house and out-buildings, first-class and common shanties. the cost of buildings at the central shaft in july, , was $ , . . the cost in november, , was $ , . . the annual rent of that portion leased to operatives is $ . a farm, containing acres of land, with a dwelling-house and barn, has been purchased, adjoining the central shaft, for the sum of $ , . the land was well covered with timber, about one-half of which has been cut for the purposes of the shaft and tunnel. there is estimated to be one million feet of hemlock timber still standing, which will be wanted in the progress of the work. this purchase was an advantageous one for the state, there having been already realized from it an amount equal to its cost. the working force at the central shaft in july, , was comprised of-- engine-men and firemen, mechanics in iron, carpenters, blacksmiths and helpers, pump men, manual laborers, -- total in july, on the first day of november there were employed at this point, in all, . of this number, were engaged out of the shaft, and in the shaft. the above enumeration does not include the resident engineer and time-keeper, stationed here in november. the depth of central shaft, when completed, will be , feet from the surface; its form is an ellipse, whose axes are and feet. on the fifth day of may it had reached the depth of . feet. at this time the hoisting apparatus was removed from the shaft, and the work of excavation ceased. the new hoisting apparatus was fitted on the first day of august, and the drilling commenced at midnight on that day. previous to the change in the hoisting apparatus, the monthly progress had averaged about - / feet per month. the advance in october and november was feet; the gain over the previous rate of progress is attributable to the practice of simultaneous blasting. on the first day of january, , the shaft had been sunk feet, leaving for excavation feet. _table showing the progress at central shaft from november , , to december , ._ ======================================== date. | distance | progress. | down. | ==================+==========+========== nov. , , | . | dec. , , | . | . jan. , , | . | . feb. , , | . | . mar. , , | . | . apr. , , | . | . may , , | . | . may , , | . | . june , ,[a] | . | july , ,[a] | . | aug. , ,[a] | . | sept. , , | . | . oct. , , | . | . nov. , , | . | . dec. , , | . | . ======================================== [a] work suspended to put in new hoisting apparatus. the present hoisting apparatus is expected to be sufficient to finish the shaft. it has two wire ropes, each , feet long. the time for a round trip is seven minutes. the engine here is of horse-power. the blacksmith shop contains two forges. at the small machine shop the repairs required here are made, as also some repairs for the west shaft. the central shaft, though designed to aid in ventilating the tunnel, was intended also to accelerate its construction by affording to the process of excavation four faces instead of two during some portion of the work; and the former chairman of the commissioners expected by the aid of machine-drilling, the shaft might be completed in one year from the time such drilling should commence within it. in this anticipation, ten vertical drilling machines were constructed to work in the shaft area and a compressor with two cylinders was provided to furnish the power for operating them. the want of drilling machines at the east end became so urgent, that these vertical ones were changed to horizontals, and used at that point, and the sinking of the shaft by hand-drilling still continues. but if the experiments now in progress at the east end with the new drilling machine shall demonstrate its superiority over hand labor, the machine will doubtless be introduced into the shaft. west shaft. this shaft has an area of about by feet, and was excavated by messrs. h. haupt & co. its depth is feet. the buildings here used by the state are the west shaft house, the new shaft building, a blacksmith shop containing two forges, a powder-house, a horse-shed, ash-house and tank-house. the buildings owned by the state and leased to operatives are a boarding-house and four old shanties built by h. haupt & co., four first-class shanties, eight common shanties, and a double cottage. the buildings at the west end, are connected on the books with those at the west shaft, and will be here enumerated. they consist of a carpenter's shop, time-keeper's office, a blacksmith shop containing one forge, tool-house, powder-house, horse-shed, brickyard shed, brickyard, engine-house, artesian wells nos. and , buildings, and two-thirds of a barn, which are occupied by the state. one boarding-house, store, one-third of a barn, the harrington farm-house, barn and out-buildings, twenty-seven common shanties and brickyard boarding shanty. these buildings, with part of blacksmith shop, part of carpenter's shop and time-keeper's office, are rented to operatives and to mr. farren, the contractor for constructing the brick arch. the cost of the structures, as reported in july, at both places, was $ , as reported in november, , this large increase was mainly occasioned by the construction of a double cottage and necessary buildings at the brickyard and west end. the amount of rents at these two points is $ , . per annum. fifteen of the tenements at the west end are leased to mr. farren, in accordance with his contract. the working force at the west shaft in july was,-- engine-men and firemen, carpenters, blacksmith and helpers, masons, truckman, pump-man, manual laborers, --- total, november st the working force at this point, including one resident civil engineer, was at this point there is one engine of -horse power and one of -horse power, and one compressor having four cylinders of a diameter of inches and inches stroke. the west heading from this shaft was advanced feet, and the east heading , , on the first day of december, . the progress for the year ending november , , at the heading at this point was . , being a fraction over feet per month. for the last four months, ending december , , the progress was . , being a fraction over feet per month, which exceeds by four feet per month the highest estimate for hand-drilling by the engineers in , and by thirty and one-third feet the estimate of mr. latrobe. the progress of the work at this heading during the last six months, making allowance for the influx of water in november, having exceeded the highest estimate for hand-drilling, should be regarded as evidence alike of the skill of the miners and the good management of the engineer and his subordinates. _table showing the progress at west shaft, east heading, from november , , to december , ._ ======================================= date. distance from progress, shaft, feet. feet. --------------------------------------- nov. , , . dec. , , . . jan. , , . . feb. , , . . mar. , , . . april , , . . may , , . . june , , . . july , , . . aug. , , . . sept. , , . . oct. , , . . nov. , , , . . dec. , , , . . ======================================= the west heading at this shaft was at first driven feet by . it has been found advisable to enlarge it to the dimension of feet inches by feet. this work has been performed by contract. the first letting was at the rate of four dollars per cubic yard, the state furnishing the materials used and removing the stone. the contractors at this rate could not pay their expenses. it was raised to six dollars per yard which was found not to pay, and in july the price was advanced to seven dollars and fifty cents. the state pay the men, charging the same to the contractors, and keep their time. good progress is made and the work is done to the satisfaction of the engineer. the east heading at this point was being enlarged also by contract, from feet by , to - / by . the work commenced on the th of july, ; the price paid is seven dollars per cubic yard; the contractors load their own stone and also that coming from the heading. the state provides the materials used, and hoist the stone to the surface. while the work of the miners at the east heading and of the contractors upon both enlargements was progressing in a very satisfactory mariner, the whole was arrested by an unexpected and somewhat sudden influx of water in the tunnel. on the th of november the miners working east from the west shaft struck a seam running across the stratification of the mountain. water soon issued from the seam at the rate of twenty-three gallons per minute. on the th, the water had risen at the foot of the shaft to two and a half feet above grade, and the work was stopped. the usual speed of the engine working the pump was forty-two revolutions per minute; it was increased to fifty-six, and at that rate it succeeded in preventing any further rise of the water. it became necessary to increase the power of the pumps. the plunger was enlarged from eight to ten inches, and a third lift pump was added. to affect this arrangement the pumps were stopped from o'clock, a. m., december th, to - / p. m. on the th. at this time the water was four feet and eight inches above grade. on the th the water was so much reduced that the miners recommenced work. the next day, at p. m., the water was struck in large quantities, the whole flow from the heading being gallons per minute. on the th, the work was again suspended, and unsuccessful attempts made to stop the water by means of wooden plugs driven into the seam. the pumps working with the longest stroke and at increased speed, were just able to keep the water from rising. on the th, at . a. m., one of the trunnions of the pump-bob broke, and seriously injured the pump gearing and boxes. on the st a new trunnion was put in, and the pump was attached to the small hoisting engine, the water now being seven feet above grade. on the th, at noon, the breakages being all repaired, the large engine was again attached to the pumps, the water then being nine feet and eight inches above grade. and, on the first day of january, at p. m., the water stood nine feet ten inches above grade at the foot of the shaft.[b] [b] at the time of the presentation of this report, the committee understood that the water was entirely removed from the shaft and tunnel. the new shaft. this shaft is located about feet westerly of the west shaft. its dimensions are six feet by thirteen in the clear. the rock to be removed from an area of eight feet by fifteen. the labor is done by contract. the first price was $ per foot; increased july , , to $ per foot. the state furnishes all the materials for construction, and the power to raise the stone and water from the shaft. the depth of the shaft will be feet when open to grade. on the first day of december, the miners working down had progressed feet, and those working from the tunnel up feet. it was then calculated that the shaft would be excavated in two months. plans for permanent pumps had been prepared; to furnish the pumps according to the plans, would take several mouths. in the meantime, a temporary pump was to be made at north adams, under the direction of the engineer. on the first day of january, about thirty-eight feet of stone remained for excavation in this shaft. the water in the tunnel stopped the work from below, and the work is driven upon one face only at the present time. there are two small engines at this point, one of fourteen and one of ten horse power. the pumps at this shaft, if constructed agreeably to the design of the engineer, will discharge sixty-five gallons to a stroke and are to be worked by a bull engine. the lift of the water will be eighty feet less than at west shaft, being discharged about feet below the surface. the west end. the work at the west end of the tunnel is under contract. mr. b. n. farren of doylestown, bucks county, pennsylvania, by an agreement dated may , , contracted to put in a stone and brick arch of the dimensions before stated, feet by , for the following prices, viz.:--earth excavation $ . per yard; brick masonry, $ per perch; stone masonry, $ per perch. contractor planks the bottom and sides when necessary at $ per lineal foot. the state furnishes the bricks at $ per thousand and the timber at $ per thousand for hemlock, and $ for spruce and hard-wood. the length of arch contracted for is feet, the whole of which is open. the state also furnishes the cement, which costs in troy, new york, from $ . to $ . per barrel, to which is to be added the freight at cents per barrel. a barrel of cement is used for a perch of masonry. the contractor agrees to construct two hundred feet of under ground tunnel, and as much more as he can before august , , at the following prices, viz.:--earth excavation at $ . per yard; brick masonry at $ per perch; stone masonry at $ . per perch. the timbering, from $ to $ per foot, lineal, depending upon the thickness of the wall. he may, under permission from the engineer, take stone and sand from the state's premises, without making compensation. payments are to be made about the th of each month for the work done the preceding month, at the rate of per cent. of the finished work. the decision of the engineer as to the method, quality, quantity and classification of the work to be final and conclusive. in order to facilitate the progress of the work and with a due regard to economy, the state has purchased the following lots of land in the vicinity of the west end, to wit:--a wood lot, containing sixty acres, at a cost of $ , ; the harrington farm; acres with the buildings, inclosing the west end and west shaft; and running half way up the mountain. this purchase was made january , , price $ , . the kingsley lot, purchased march , , at $ , . . the timber used by mr. farren is obtained from these lots. the tops of the trees are cut into wood and used at the brickyard. about five hundred cords of wood has been cut on the harrington, and one thousand cords on the kingsley lot, for the use of the brickyard, and is now on hand. the necessity of making the bricks required for the arch tunnel is apparent. they could not be furnished by individuals at north adams. , , before the yard at the west end was fitted up, were purchased at springfield at $ per thousand; the freight of which to north adams was $ , and the teaming to the west end $ per thousand. if to these prices be added the depreciation and waste from handling, the cost will reach $ for all that could be used in the work. it is the opinion of the engineer and superintendent of labor, that the bricks made by the state will cost less than $ when delivered to the contractor. mr. farren began work under his contract june , , and early in december the brick-work at the top of the arch had entered the mountain. the masonry was commenced about, twenty-five feet west of the point first selected, so that the open masonry will in fact be feet long. about thirty feet of invert is left uncovered the present season, under an apprehension that the bricks on hand will only supply what will be wanted in the drift, in order to prosecute the work with dispatch. the invert has been properly protected, and its preservation may be expected. at the beginning, the invert and the sides to the spring of the arch was laid with five courses of brick, and the arch with six. the masonry has been strengthened to meet the effect of the soft ground and increased pressure to eight bricks thick all round. where rocks are found, it will be reduced at the bottom, and perhaps at the top. the excavation of the drift is in progress and is carried on with two galleries. the lower one is of timber, and is at the bottom three feet below the grade of the road. this gallery is ten feet wide and ten feet high. the upper gallery, also of timber, is ten feet wide and four feet high, and the space between the galleries is about ten feet. as the arch is driven in, the top of the invert is - / feet below the grade of the road, and inches below the timber of the lower gallery. the top timbers of the upper gallery constitute the top timbers of the tunnel during the excavation. they are supported above the masonry and the arch is turned under them. side drains, six feet high and four feet wide, are excavated ahead of the galleries, to assist the drainage of the ground through which the galleries and tunnel are driven. the water from these drains is let into the tunnel through its sides, and runs out with the general drainage upon the invert below the road-bed. holes are left in the invert at proper intervals to facilitate this drainage. the side drains are hereafter to be filled with stone, which will constitute a blind drain, and also afford a proper support to the masonry. the work at this point is of difficult prosecution, but the performance of the contract may be confidently expected. the brickyard. the expenditures at the brickyard on the first day of july, , had reached, $ , of this amount the brick machines, shafting, gearing, &c., cost $ , and the engine, , --------- $ , twenty-four thousand bricks can be moulded daily. the drying yard is feet long and feet wide. the kiln shed is feet long and feet wide, and of capacity to burn all the bricks that can be moulded. there are six brick machines, four of which are in use. they are driven by an engine, and used alternately, two each day. the making of bricks at the yard commenced june and closed october , . about , , bricks were made, of which per cent. are sufficiently hard for use in the tunnel, which is estimated to be sufficient to complete the feet of tunnel now under contract. the clay for the bricks is found near the yard, and hitherto a sufficiency of sand has been found in the vicinity; but it is less abundant than the clay. miscellaneous. in addition to the property enumerated under the preceding heads, the state has at north adams, a freight house, cashier's office, engineer's office, stable and two coal sheds, and opposite the west end on the pittsfield and north adams railroad, an additional freight house. there are also two instrumental station houses on the east and west summits respectively, all of which are occupied by the state for the purposes of the enterprise. there is also one seven-horse engine and three small compressors. tho state has also four mule teams, three of four, and one of two animals, making fourteen in all. there were also used on the work in the early part of the year, twelve or fourteen horses, employed in hauling clay, sand, wood, &c. six of these have been sold to mr. farren, and the remainder are to be disposed of. to this enumeration should be added five horses and three or more carriages kept at the stable at north adams for the transportation of the engineers, superintendent, master mechanic, &c., from point to point along the line of operations wherever their presence and services might be needed. the expense of the stable, including the pay of the keeper, for the past year, was, $ , which covers the price of three carriages, $ and one harness, ------- --------- leaving, $ , for the expense of keeping five horses, and the repairs; which is about five dollars per week in all. the charge for keeping horses at the stable in north adams, is five dollars per week for feed; and the cost for the use of one horse and wagon from north adams to the east end, is four dollars. these horses were also used to transport the commissioners and the committee visiting the tunnel, when required for that purpose. the road between the tunnel and north adams. it is proposed to change the course of, the road as it emerges from the tunnel, and two lines have been surveyed, which, diverging near the approach cut, unite again about midway from thence to the village. the difference in length is about thirty feet. the northerly line is the least expensive to construct, and best favors the landholders on the route. it has the recommendation of the engineer, and the approval of the consulting engineer, and will probably be selected. there are reasons for an early location of this portion of the road which call for a prompt action in this behalf on the part of the commissioners, which will undoubtedly be taken. the following table shows the expense of the tunnel and the land and works connected therewith under the administration of the commissioners, as found november , :-- deerfield dam, $ , race, , excavation and masonry at east end of dam, , wheel pits, , gates and overflow, , ---------- $ , east end heading, , east end enlargement, , east end heading enlargement, , central shaft, , west shaft, , west approach, , building east end, , building west end and shaft, , building central shaft, , building general account, , engineering and superintendent, , machinery west shaft, , machinery east end, , machinery central shaft, , machinery deerfield dam, , machinery general account, , machinery west end, land and land damages, , ------------- $ , , the following table shows the cost of the works under the classification of outside and inside expenditures, as given by the consulting engineer. _outside expenditures._ deerfield dam, $ , buildings east end, $ , buildings west end and west shaft, , buildings central shaft, , buildings general account, , ---------- , machinery east end, $ , machinery west end, machinery west shaft, , machinery central shaft, , machinery deerfield dam, , machinery general account, , ---------- , land damages and land, , engineering and superintendence, , ----------- total outside expenditures, $ , _inside expenditures._ east end heading, $ , east end enlargement, , east end bottom, , ----------- $ , central shaft, , west shaft headings, &c., , west end approach cut, drifting and arching, , total inside expenditures, ---------- , ------------- total expenditures to november , , $ , , the exact correctness of any classification of the expenditures is not very important, inasmuch as the sum total is chargeable to the construction of the tunnel; but the committee do not see the propriety of charging the engineering and superintendence exclusively to the outside expenditure. they have seen a classification which gave,-- amount put into buildings machinery, &c., $ , spent in the work, , ------------- total, $ , , general summary of the force employed on the tunnel, november , . thomas doane, chief engineer, salary, $ , he providing his horses. paul hill, superintendent of labor, , his horse furnished to him. _in the chief engineer's office._ h. g. burgess, master mechanic, soon to leave, $ , john christiansen, mechanical draftsman, , austin bond, clerk, &c., , edward stowell, temporarily engaged in making fuse, , roswell houghton, hostler in village, $ . per day. charles p. bradley, hostler at t. doane's house, $ per month. roger tappan office boy and rod-man for mr. granger, $ . per day. _west end._--wages from $ . to $ per day, _brick-yard._--wages from $ to $ . per day, _new shaft._--wages from $ . to $ per day, _west shaft._--wages from $ . to $ . per day, w. p. granger, civil engineer, is resident in charge of west shaft, new shaft and west end. salary $ , , _central shaft._--wages from $ . to $ , this number includes the time-keeper and h. g. coolidge, resident engineer. _east end._--wages from $ . to $: . , f. w. d. holbrook, resident engineer, in charge at a salary of $ , , add force in general charge and not confined to any particular point, ---- total in the employ of the state, add at the west end in mr. farren's employ, about ---- total employed upon the tunnel, experiments. the interest awakened by the magnitude of the undertaking to tunnel the hoosac mountain, and the anxiety manifested for its early completion, prompted the commissioners to the discovery of means to accelerate the progress of the work. their attention was naturally directed to the operation of drilling, and with a view of improving upon the machine drill used at mont cenis; scientific mechanics have been employed to devise and construct a drill that should attain that end. as a first step gouch's patent of the hollow piston-rod, was purchased for new england, for the sum of five hundred dollars. after which, a mr. gardner was employed to construct a drill; but his efforts failed of success after an expenditure of thirteen hundred dollars. a mr. butler was engaged to devise a machine, but in the course of studying the subject, his health failed and his services were lost. a mr. hanson completed a machine which promised some success; but on trial it proved a failure. a second machine called the brooks, burleigh and gates drill, was made under the direction of the commissioners at fitchburg. this machine was put upon the works and used for several months. a third machine, called the burleigh drill, an improvement upon the preceding one, was next produced, which is now at the works on the east heading. about $ , was spent upon these experiments, resulting in the construction of the brooks, burleigh and gates drill, and the manufacture of four of them. about one-half of this expenditure may be charged to these last drills; the other was unproductive of anything of value. the brooks, burleigh and gates drill was patented, but the commonwealth has the right to use them in the construction of the tunnel. these machines will now be described. the hanson machine. this machine has a cylinder and valve motion, similar to a steam-engine. the piston is hollow, the drill-bar which may be of any required length, passing through it, is moved with the piston, by means of four wedges or cams on each end of the piston; these cams are pressed on the drill-bar by means of sliding collars forced upon them by a complex arrangement operating alternately. the drill-bar is rotated by means of a ratchet operated by a spiral groove in the shield of the machine. the main difficulty in this machine was in the complex arrangement for forcing the collars upon the cams or wedges. it did not work well in a horizontal position. the machine consisted of one hundred and twenty pieces, and weighed five hundred and ninety-five pounds. the brooks, burleigh and gates machine. this machine has a hollow piston, the drill-holder being a screw passing through the piston, moving with it, and fed through it, by means of a nut on the end of the piston-rod. this nut is held by means of a cap or union nut, as it is called, the union nut being screwed on to the coupling, and the coupling nut screwed to the piston-rod. the feed-nut protrudes through the union nut, and is allowed to turn round in it. on the end of this feed-nut is a ratchet gear covered by a ratchet-band with an arm upon it, all moving with the piston. the ratchet arm moves up and down in a spiral groove, the groove being in a shield attached by screws to the cylinder; on the ratchet-band there is a pall and two springs, one under the other. one of the springs holds the pall in gear, the other holds it out of gear. as the piston moves down, the outer spring comes in contact with a trip which is on the shield and is lifted up, allowing the under spring to throw the pall into the ratchet, and as the piston is moved back, turns the nut round, thereby feeding the screw forward. at the extremity of its backward stroke, the pall comes in contact with another trip on the shield which lifts it out of gear, the outer spring having a catch upon it which holds the pall when thus lifted out. the rotary motion is given by a ratchet on the coupling-nut, covered by a ratchet-band the arm of which moves in a spiral groove in the shield similar to the other, only having a spring to hold the pall in the ratchet; this rotates all the parts on the piston except the ratchet-bands and cross-head. the latter is held between two check-nuts on the coupling-nut. to this cross-head is attached a bar which communicates with a valve which opens the port when the piston moves back, and shuts it when it moves forward; the air is always on during its backward stroke. the piston having a greater area on the forward than on the backward stroke, overcomes the backward pressure and moves the piston ahead, and when cut off, the continued pressure forces the piston back. this machine is automatic; generally running until some portion of it is destroyed. no part of the machine has been found strong enough to withstand the friction upon it for any considerable portion of time. the union nut has proved its weakest point, and the breaking of this generally destroys that part of the piston to which it is attached. another point of weakness is the feed ratchet-band, the springs of which are almost continually breaking. the machine consists of eighty pieces; twenty-three of which are screws, fifteen pins, and seven pieces of cast iron. it weighs pounds, runs about strokes per minute, and costs about $ . its longest run without breaking has been five days. the run of one of them two days without breaking during the time, is considered fortunate. the average breaking is more than one a day. a table showing the list of breakages will follow this description. the piston-head of this machine has a diameter of - / inches. the diameter of the piston-rod is inches at the large end and - / at the small end. so there are - / square inches of air area to drive the drill ahead into the rock, and - / to draw it out; but as the air is not taken off from the front end, the actual pressure is upon an area of the difference between the two, or - / square inches. table showing number of drilling-machines broken, &c. column headers a. no. machines broken. b. cross heads c. cylinder flanges. d. coupling nuts. e. feed springs. f. feed palls. g. ratchet covers. h. valve stems. i. new packing. j. tapper bars. k. screw spindles. l. union coupling nuts. m. feed nuts. n. shields. o. piston heads. ====================================================================== . [a] [b] [c] [d] [e] [f] [g] [h] [i] [j] [k] [l] [m] [n] [o] ---------------------------------------------------------------------- july , - - - - - , - - - aug. , - - - - - , - - - , - - - - , - - sept. , - - - - - , - - - , - - - - , - - - oct. , - - - - - , - - , - - - - - - , - - nov. , - - - - - , - - - - - , - - - - - - , - - - - - - -------------------------------------------------------------- , ====================================================================== about forty of the brooks, burleigh and gates machines have been used at the tunnel; of these eight or ten were originally vertical, and intended for use at the central shaft. at the commencement of their use, the machines were new and had their best wear in them; there were from twenty to twenty-four at the beginning. in a short time they began to break down, but by putting on a large repair force and converting the vertical machines into horizontal ones, a fair supply was kept up for from two to three months, at the end of which time the greatest machine progress was attained, viz., fifty-four feet and six inches, in september. after that the progress diminished very much, and in proportion to the giving out of the machines. it is the opinion of the engineer that if a constant supply of machines could have been furnished, that the progress would have reached a point much beyond that obtained by hand labor; but with the stoppage of the supply, the number of machines that could be kept in working order was daily reduced, and at last it fell down to two or three, and finally, at times, none were in condition to work. the frames were, however, kept in the tunnel to await the completion of the burleigh machine, the reception of which was retarded till late in october; much beyond the time anticipated by the commissioners, although the work of their construction was carried on continuously night and day. they came at intervals of several weeks, two at a time; the first of which were put into the tunnel on the thirty-first day of october. through the month of december, four of these machines were at work. the burleigh machine. has a solid piston (so called,) which has a hole in its back end to allow the feed-screw to pass in without touching; the drill is secured to this piston. on the back end of the piston is a section of a ball used as a cam, which works the valve and the feed-motion. the valve is rotated by a rod lying on the band of the cylinder; upon this rod are two cams which perforate the band of the cylinder. the action of the piston brings the ball on its end in contact with these cams, rocking them up and down; the rod to which they are secured being connected with the valve, imparts to that its motion. this machine is fed altogether on ways, or a bed-piece, upon which is the feed-screw; the feed-nut is upon the end of the cylinder-band. to this feed-nut is attached a feed-ratchet, which is held between two collars, allowing it to turn round. upon the cylinder-band is a lever, one end of which passes through the band; upon the other end is a pall. the motion of the piston raises the lever up, pressing the end containing the pall against the ratchet which turns the nut on the feed-screw, thus moving the machine forward. the rotating ratchet is in the band of the cylinder and has a spline in it, and a pall on its outside. the piston having a spiral groove is turned by this ratchet as it moves down. on the return of the piston, the pall drops into the ratchet and then the piston is turned. the piston is not encumbered with any machinery, and moves alone; its area of air is greater on the forward than on the backward stroke; the alternation of the valve admits the air. the machine, like the one last described, contains eighty pieces; it has the same number of screws and pins, and weighs pounds including the ways or bed-piece; without the ways its weight is pounds. its number of strokes is about per minute, and its blow somewhat lighter than that of the other. this machine is not entirely automatic; the feed-motion not working regular; when it does not, it is fed by hand, which is a simple process. these machines stand the work much better than those first made at fitchburg. their average time in the tunnel without repairs in the interval, is about five days; they have needed repairs in two days; one remained at work fourteen days. they accomplish double the work without repairs that those do which were made after the previous pattern. there is a further advantage in using the burleigh machines; their breaking, when it occurs, is not very serious, the injured parts consisting mainly of cams, can generally be replaced at the tunnel; whereas for the repairs on the brooks, burleigh and gates machine, the dependence to a very great extent has been upon the machine shop at fitchburg. the piston-head of this machine has a diameter of - / inches. the diameter of the piston-rod is at the large end, inches, at the small end, - / inches. so the number of inches of air area, is - / when the drill is propelled upon the rock, and - / when returning from it. a full complement of men to work the machines first used, would be, perhaps, thirteen. mr. gates, who superintended their operation in the first instance, began with fourteen, but they were reduced to thirteen. the burleigh machine practically requires feeding, and a full set at work would probably demand fifteen men for their successful operation. the value of these machines has not yet been ascertained. the committee are of opinion that when a full complement shall have been obtained, so that the workmen can have at all times a full supply upon the frames, that greater progress can be obtained by them than by hand drilling; and after a few months operation, the cost of using them, in comparison with hand labor, can be fairly tested. but as the brooks, burleigh and gates machine has been abandoned, no useful results would be obtained by comparing the expenses within the tunnel during the months of july, august and september, with three corresponding months when hand drilling was carried on, and no satisfactory comparison can be made between the working of the burleigh machine and hand drilling, until a sufficient number of machines has been introduced into the tunnel to keep the men fully employed. it is to be hoped that machines sufficient to make the test may be soon obtained, and that this desirable information may be made known. the introduction of the first machine into the tunnel, before its capacity, strength, and expense of working had been fully tested, was unfortunate, inasmuch as its use there delayed the progress of the work. the second machine gives such promise of success, that it will be continued in use in the tunnel until a fair test has been made. but should the burleigh machine prove unsuccessful, and further attempts with machines be attempted, the committee recommend that their usefulness be tested outside of the tunnel, and meanwhile the excavation with hand drills be resumed. experiments with dr. ehrhardt's powder. the first blast was fired in the tunnel at the east end on the th of november, but owing to the presence of charcoal or some other substance in the article, a poisonous gas was evolved which effected the miners disagreeably, and drove them from the work. the subsequent experiments at this point were not satisfactory, and were discontinued, and subsequently resumed at the central shaft, where it was used most of the time for a week, varying its composition from time to time. at the close of the week, while preparing for the last blast, a premature explosion took place, resulting in the death of one of the miners, and the injury of three or four others. the material result of this experiment was as follows:--with days' work and - / lbs. of powder, buckets of stone were removed; while in the preceding week, using common powder (schaghticoke) with - / days' labor and lbs. of powder, buckets of stone were taken out. the cost of the experimental powder is about twice as expensive as the common powder, and its superior strength is apparent from the above result. experiments with nitro-glycerine. during the summer, some experiments have been made with this explosive agent. a quantity, costing $ . , was brought to the works by colonel schaffner, who exhibited the action of the material in various ways, with a view of testing its power, and the comparative safety of introducing it instead of powder. after repeated trials outside of the works, during which about three-fifths of the material was consumed, it was introduced into the tunnel at the west shaft with the following result: it was used for three days at the east heading of the west shaft; the advance made in the heading was for the time, - / feet;--being an advance of . feet per day, and at the rate of . feet per month. in these three days there were taken out of the enlargement . yards of stone. to remove this quantity with powder would cost, on an average, per yard, $ actual cost with glycerine, ----- difference, $ multiplied by . , gives. $ in the same time there was removed of heading . yards. to remove an equal amount by powder costs, per yard, $ actual cost with glycerine, per yard, ------ difference, $ $ . multiplied by . , gives -------- $ , cost of the glycerine used during the three days, being / of $ . , -------- saved, by using glycerine, in three days, $ which is a saving by the use of glycerine, per day, of $ . and allowing three hundred successful working days in the year, an annual saving of $ , the progress made at the west shaft on the east heading the present year, ending december , , is feet and inches. this progress was somewhat lessened by the influx of water in december. the monthly advance has been feet and inches. the average of the eleven months ending with november is feet and inches. assuming the progress made with glycerine during the three days of its use to be obtainable throughout the year, the monthly progress, using that material, would be feet and inches, on a calculation of twenty-five days to a month, which would give an annual advance of , feet. without vouching for results so favorable to the progress of the work, it is impossible to overlook the importance of the experiment; and the committee are of opinion that this material, if it can be procured, should be introduced into the tunnel and shafts, and a thorough experiment made, in order to determine whether it can be used with an advantage even approximating to that shown by the first trial. experience has proved that the rock at the hoosac mountain is of a peculiar character: comparatively easy to drill, but extremely hard to displace, and that its advantageous excavation requires a strong explosive agent. the difference in the use of weak and strong powder is at once observed, and the effect of simultaneous blasting, by the aid of electricity, is proved by the increased progress of the work since it has been used. it would seem evident, then, without the aid of experiment, that an explosive agent, possessing eight times the power of common powder, would be a valuable auxiliary to this undertaking; and that if such an one could be obtained, and safely used, no time should be lost in procuring a supply. the use of nitro-glycerine in england is not uncommon; its components are well known; and the committee are informed that it might be advantageously manufactured at any point where it is used. electrical firing. the experiment of simultaneous blasting by electricity has been made with admitted success. the increased progress in the central shaft from an average of about - / to feet per month, demonstrates its utility, and will undoubtedly insure the continuance of that mode of firing in preference to the method formerly practised. the troy and greenfield railroad. the completion of the railroad from greenfield to the tunnel has been contracted for with b. n. farren, for the sum of $ , , exclusive of the cost of depot buildings, turn-tables, and engineering expenses. the road to be opened for travel to shelburne falls by the th of november, , and to the tunnel by the th of july, . a lease of the same has been executed to the fitchburg and the vermont and massachusetts railroad companies, at a rent of $ , per year, to expire on the completion of the tunnel, or whenever the work on the same shall be stopped, by competent authority. mr. farren commenced work under his contract about the th of october. at this time there were about four miles of track,--exclusive of that which had to be removed with the trestle-bridges,--built by mr. haupt. some portions of the track were in fair condition; but the larger part of it must be relaid. many of the ties are of hemlock; they are all decayed and must be removed, and new ones substituted. none of the bridges were strong enough to be used, and the timber of which they were constructed is too much decayed to be used for building purposes: there is on hand in addition to the track laid, chairs, or connecting joints, sufficient to lay five miles of rails; also about ten thousand chestnut ties. such of these as had been properly piled are sound. many of them, however, are so much decayed, as to be unfit for use. the road-bed has in many places been injured by rain and frost. at exposed points near the river, it is entirely destroyed. comparatively speaking, there was little masonry on the line. with the exception of one pier, the bridge masonry at green river will be taken down. all the deep ravines were crossed by trestle work, and consequently there were but few culverts. of these some small ones are still standing in good condition. of the bank wall built, about one-half remains,--the remainder has either fallen down, or will be taken down and rebuilt. very little alteration will be made in the general location of the line or its gradients. the curvature will be very much modified and improved. some sharp and reversed curves will be entirely saved by the substitution of straight lines. others, where the expense of reduction is not very heavy, will be materially changed. the alterations below shelburne falls are substantially as follows:-- a straight line substituted for one °, one ° and one ° curve. one ° curve substituted for one ° curve. four ° " " " four ° " one ° " " " one ° " three ° " " " three ° " five ° ' " " " five ° " one ° ' " " " two ° " one ° and two ° curve substituted for three ° curve, saving ° and feet. one ° ' curve substituted for one ° curve. one ° " " " one ° " three ° " " " three ° " one ° " " " two ° and one ° curve. two ° " " " two ° curve, saving ° and feet. the same plan for improving the line above the falls will be pursued, so that when completed, the road combining the alignment with the gradients will, in the judgment of the engineer, be "superior for doing economically a heavy traffic, to any railroad in new england which runs east and west." at green river there will be substituted for mr. haupt's bridge of feet built on a curved line one of feet, to be constructed on a straight line. the remainder of the ravine to be made a solid embankment. all the bridges on the line are to be "howe's truss," and equal in strength and durability to any in new england. the trestle-work has been removed, and the ravines where it was placed are being filled with substantial masonry and solid embankments. on the first day of november mr. farren had about fifty men employed; on the first day of december, two hundred and seventy-five, and on the th of december, when one of the committee visited the line, he had over three hundred. about one-third of the masonry for green river bridge has been built, and the stone is quarried for the other bridges. nearly one thousand yards of culvert masonry and three hundred yards of bank wall have been constructed, and from forty to fifty thousand yards of earth removed. the timber for green river bridge is sawed and will be framed in january. the material for all the bridges below shelburne falls has been contracted for, to be delivered early in the spring. twenty thousand ties have been purchased, together with posts and boards for fences. the work at the rock-cut near shelburne falls will be commenced in the month of january. on the line below shelburne falls, there will remain in the road, the following sharp curves, to wit: in the track as laid and not disturbed, four of six degrees, and in the remainder of the line, six of six degrees, three of seven, and two of eight. one of the eight degree curves, is through a long heavy cut, and cannot be reduced without great expense. the other is near the deerfield river crossing, where all trains will be required to run slow. it cannot be avoided without a tunnel or a curve over the entire bridge. the three seven degree curves occur in heavy rock-cuttings, and these are all the sharp curves that are contained in a space of thirteen miles. above shelburne falls the alignment and grades are more favorable. from the tunnel to the deerfield river crossing, below shelburne falls, a distance of twenty-two miles, there is but one ascending grade going east; its location is about two miles west of the falls; it is one-half mile in length, and is thirty-five feet to the mile. within the same space going east, there are the following descending grades, to wit: one of forty-five feet per mile for , feet, one of forty feet for , feet, one of twenty-eight feet for , feet, and one, near the village of shelburne falls, of fifty feet per mile for , feet. the remaining grades are from five to twenty feet per mile. the sharp curves remaining after the proposed improvements will be as follows, to wit: near the depot grounds at shelburne, and running through the village, there is necessarily one eight degree curve, and on the seventeen miles between the falls and the tunnel, there occur thirteen six degree curves. a slight change in laying the track will increase the radius of these curves to , feet. this in some cases can be done. the county commissioners have been called out and have made an adjudication in regard to the public crossings and alterations of highways between greenfield and shelburne falls. the whole work below the falls is under good progress, and is being prosecuted with great vigor. the laying of the track can be commenced as early in the spring as the season will admit, and its extension to shelburne falls, may, in the opinion of the engineer, be expected early in october. it appears from the foregoing, that of the work now in progress on the road and tunnel, their is performed by contract,--the construction of the railroad from greenfield to the east end of the tunnel; the enlargements east and west in the tunnel at the west shaft; the excavation of the new shaft; and the arch masonry and excavation at the west end; while the work at the east end, at the central shaft, the heading and lifting at the west shaft, the lifting at the new shaft, and the work at the brickyard has been performed by the state. no criterion has been afforded enabling the committee to determine upon the comparative economy of the different modes of operation. the commissioners in their able report in , speaking of the manner of constructing the tunnel, say: "it would not be wise nor according to any precedent for the state to expect to get the work done at the contract price if it should turn out to cost more. it would certainly get no abatement if the price was found to be exorbitant. we are clearly of the opinion that it should not be constructed by contract, excepting in so far as parts of the work may be in detail to the men actually at work upon it, and even such contracts should' not be permanent in their character." that the commissioners in april last entertained the idea of inaugurating and continuing the contract system so far as the same should prove economical for the state, satisfactorily appears in the following letter: boston april , . hon. tappan wentworth, _chairman of hoosac tunnel and troy and greenfield railroad committee._ dear sir:--hearing that questions have arisen in regard to the propriety of contracting the work upon the hoosac tunnel, it may not be improper for me to say that that subject (contemplated in the act of ,) has for a long time engaged the serious attention of the commissioners, who have already a contract for constructing a portion of the west end, before the governor and council, awaiting their approval under section of chapter of the acts of . when the economic value of their new facilities shall be demonstrated, they expect further to avail of this system far as the interest of the state (as represented by the rapid, economical and certain progress of the work,) shall warrant. while the high prices now prevailing will probably render the letting of large jobs at this time injudicious, they are not of short contracts, or of letting portions of the work to the miners by the piece. very truly yours, j. w. brooks, _chairman_. the committee coincide with the views of the commissioners. and the justness of their remarks, that the state must not expect to have the work done at less than its cost, is borne out by the operations under the contract for the west end enlargement, where the state has increased the contract from four to seven dollars and fifty cents a perch, in order to insure the miners a compensation for their labor. it may be proper to state in this connection, that the labor done upon the road and tunnel by early contractors, has not tended to a "rapid, economical and certain progress of the work," and that if even the whole work should be put under contract, the interest of the commonwealth would require the continuance of a commission, and the services of an engineer of the highest skill and integrity to superintend its performance in order to avoid a loss and damage similar to that which occurred to the state while the work was under the nominal control of the troy and greenfield railroad corporation. the retirement of all the gentlemen who comprised the board of commissioners, first appointed under the legislation of , affords the committee an opportunity to acknowledge the eminent talent and ability which they respectively possessed for the discharge of the important duties assigned to them, and to bear testimony to the industry and intelligence displayed in their elaborate and comprehensive report upon the subject of the railroad and tunnel in . it was fortunate for the state in that crisis in the affairs of this enterprise to be able to command so much practical information upon a question so interesting and important, and at the same time so difficult of solution. but in addition to the duty of furnishing an opinion of the feasibility and mode of constructing the tunnel, and of the propriety of opening this line of railway communication with the west, the commission was instituted to carry on and superintend a most important and difficult public work, involving the expenditure of several million dollars. yet each of the gentlemen composing the board was engaged in other duties requiring substantially their whole time and attention. under these circumstances their personal observance of the progress of the work could not be given to a degree satisfactory to the public, or essential to the interests of the state, and the responsibility of the operations came to devolve upon the engineer at the works, and the chairman of the commissioners in boston. these irksome labors were discharged with diligent faithfulness, and as the event has proved with a physical suffering to one of them that has called forth a general expression of regret and sorrow. by chapter of the acts of , the governor is authorized to draw his warrant on the treasurer for such sums as may be required, from time to time, by the commissioners, for the purpose of carrying out the provisions of law for the completion of the tunnel and railroad. the commissioners under this enactment have made monthly requisitions upon the governor, transmitting at the same time vouchers for the expenses of the preceding month; and upon this information and requisition the warrants have been drawn. by the chapter of the acts of , a general supervision of the work is vested in the governor and council, with power to "correct abuses, remedy defects, and impose and enforce requirements in such manner as the interests of the commonwealth shall, in their judgment, require." as the commissioners exercise a delegated power, there would have been a manifest propriety in requiring of them, from time to time, a report upon the progress of the work, and of their own doings even under the act , so that the governor might have been more fully provided with information touching the necessity of the requisitions. but under the act of , it appears essential that the commissioners should report monthly to the governor and council the general plan of operations pursued, the progress of the work, and the manner and extent of their own superintendence of the same. the committee are therefore of opinion that the commission should be reorganized in such manner that the state could command the whole time of its members: that a greater degree of personal attention should be given by them to the work than it has heretofore received: that the commissioners should keep minutes of their doings which shall be open to the inspection of the governor and council, and the appropriate legislative committee: that their monthly communications to the governor and council should embrace, in addition to the past, and the requisition for the current month, a report of the operations, the progress of the work during the previous, month, and the manner and extent of their own superintendence of the same. the committee are also of opinion that a due regard to economy in conducting the enterprise requires that the commissioners should at once, by experiment, ascertain the probable time required to excavate the enlargement of the tunnel, and that the work upon the enlargement be regulated and pursued with a view of avoiding any unnecessary delay in operating the road after the heading is removed. * * * * * in concluding this report, the committee cannot forbear to express their obligations to mr. doane, the engineer in charge of the work, for the assistance rendered by him in aid of their labors, nor withhold their approbation of the faithful and able manner in which he has discharged the duties of his office, so far as they have come under their observation. the committee are indebted to mr. hill, the superintendent of labor, for his uniform attention during their examinations, and they fully recognize his capacity for his position, and his interest in the operations. they are likewise indebted to mr. hall, the intelligent master of the machine shop, for very valuable information concerning his particular department. and also to mr. field, the able and efficient engineer of the railroad, for a very satisfactory report upon that portion of the work under his direction. tappan wentworth, ----- -------,[c] william l. reed, _of the senate._ moses kimball, george b. loring, sylvander johnson, b. f. taft, e. h. chisholm, silas jones, james r. gladwin, _of the house._ [c] hon. alvah crocker has not acted on the committee since his appointment upon the commission. appendix. [a.] _sketch of the proceedings of the troy and greenfield railroad corporation, from its organization to the surrender of the road under the mortgage, and the adoption of the work by the commonwealth._ the charter of the troy and greenfield railroad, was granted in , and authorized the construction of a railroad with one or more tracks, from a point on the vermont and massachusetts railroad, at or near greenfield, to some point on the line of new york or vermont, convenient to meet or connect with any railroad that may be constructed from any point at or near the city of troy, on the hudson river in the state of new york. its capital stock was limited at $ , , . the corporation was authorized to contract with the owners of any contiguous railroad leading into or from either of the states of vermont or new york, for the use of the whole or any part thereof, or for the running and operating the two railroads conjointly, or for the leasing of such contiguous road, or for any other road, or for the letting or hiring of their own road to the owners of such contiguous road, or of any other road which composes a part of the railroad line between the cities of boston and troy, of which the troy and greenfield railroad shall be a part. the first meeting under the charter was held june i, , at which subscription papers were voted to be issued and circulated, in order to organize the corporation. in , march , the subscribers to the stock held their first meeting, and organized under the charter. at the annual meeting, february , , the stock was apportioned among the neighboring towns as follows:- ashfield, shares. charlemont, " colrain, " conway, " greenfield, " hawley, " heath, " leyden, " monroe, " rowe, " shelburne, " buckland, " florida, " adams, , " williamstown, " clarksburg, " hancock, " deerfield, " bernardston, " gill, " whitingham, " reedsborough, " stansford, " , shares. it was also voted to apportion the directors among the towns in the following manner, to wit:-- north adams, ; florida, rowe, heath and monroe, ; colrain, buckland and hawley, ; shelburne, ; greenfield, deerfield and conway, ; williamstown and whitingham, ; charlemont, ; and one director at large. before the annual meeting in , the directors had voted to assess three per cent. upon each share of the capital stock. this vote was passed april , , and on the first day of october in the same year, they voted that the construction of the road from the state line at pownal, vermont, to adams, and from greenfield to shelburne falls, be put under contract as soon as sufficient subscription shall have been obtained therefore, and that the two ends aforesaid shall be constructed simultaneously. , january , the treasurer had received the sum of $ , . , and had paid out on bills approved by the president, $ , . , leaving a balance in the treasury of $ . . sundry assessments amounting in all to per cent. upon the subscriptions, were afterwards voted, the last on the th of may, . these assessments were rescinded by a vote passed july , , and it also voted that the several amounts heretofore paid by individual stockholders, except on assessment laid april , , be credited to their several accounts on assessments now or hereafter to be made. , october , the contract with messrs. gilman and carpenter, was ratified, and on the th, the president was authorized to execute it. the committee have not found this contract nor any record stating its provisions. december , , a committee reported that the whole amount of stock subscribed, was $ , , of which $ , was payable in land damages and materials for the road; and that messrs. gilmore and carpenter had subscribed for shares of stock, to wit, $ , . on the th day of january, , the directors voted to break ground the next day, and on the th of may in the same year, they voted to expend a sum not exceeding $ , , in experiments upon the east side of the mountain, at or near the mouth of the proposed tunnel. in , the corporation petitioned the legislature for a loan of the state credit for two million dollars; but the application was unsuccessful. the failure to secure the aid of the commonwealth, appears not to have discouraged the corporation, for on the th of august, , the directors voted that they would proceed forthwith from adams to the new york line, and simultaneously incur all the necessary expenses to make thorough experiments with such machines as promise to facilitate the construction of the tunnel, and when the road is begun from greenfield, it shall be after an arrangement is made to construct it to the foot of the mountain in florida and connect in some way with the road at north adams. the troy and greenfield railroad corporation having directed its attention to a connection with the troy and boston railroad company through a portion of the state of vermont, and a charter having been obtained from the legislature of vermont, incorporating the southern vermont railroad company, whereby such connection could be made, a committee of the directors of the troy and greenfield railroad company and of the southern vermont railroad company made an agreement, subject to the modification or ratification of the stockholders of each company, "that the stock of both of said companies and their franchises from said greenfield to the west line of pownal, in the state of vermont, shall become and be one joint, consolidated stock and interest, with equal and common rights and privileges to the stockholders of both companies;" it being understood that an application shall be made to the legislature of vermont for a change of the name and style of the joint corporation mentioned in the said act of the vermont legislature. this report was made to the board of directors, and it was voted that the same "be accepted and adopted, recorded and placed on file." subsequently the southern vermont railroad was leased to the troy and greenfield corporation on a perpetual lease for $ , per year; and the st of april, , it was purchased by the troy and greenfield corporation for the sum of two hundred thousand dollars, with money advanced to the last named corporation by the commonwealth. in the report of the commissioners on the troy and greenfield railroad and hoosac tunnel, the southern vermont railroad is estimated to have cost from $ , to to $ , only. in , another application was made to the legislature for a loan, but with the same result as in . in both instances, committees reported in favor of the application. in , the application was renewed, and was successful. the act was passed on the fifth day of april, . by the first section, the treasurer was authorized to issue scrip, as certificates of debt, for the sum of two million dollars, to be expressed in the currency of great britain or in federal currency, as the directors of the troy and greenfield railroad should elect, to bear an interest of five per cent., payable semi-annually, and redeemable in thirty years, for the purpose of enabling the troy and greenfield company to construct a tunnel and railroad under and through the hoosac mountain, in some place between the "great bend" in deerfield river, in the town of florida, at the base of hoosac mountain, on the east, and the base of the western side of the mountain, near the east end of the village of north adams, on the west. the scrip was to be delivered to the treasurer of said troy and greenfield railroad company in the manner and upon the conditions following:--$ , , when it should appear to the satisfaction of the governor and council that said company had obtained subscriptions to their capital stock in the sum of $ , , and twenty per cent. upon each and every share of said six: hundred thousand dollars should have actually been paid in, and seven miles of their railroad and one thousand lineal feet of their said tunnel under the hoosac, in one or more sections, of size sufficient for one or more railroad tracks, should have been completed. $ , , when ten miles of their said railroad, in one or two sections, and ten thousand lineal feet of their said tunnel, in one or more sections, should be completed. $ , , when fifteen miles of their said railroad, in one or two sections, and three thousand lineal feet of their said tunnel, in one or more sections, should be completed. $ , , when twenty miles of their said railroad, in one or two sections, and four thousand lineal feet of their said tunnel, in one or more sections should be completed. $ , , when twenty-five miles of their said railroad, in one or two sections, and five thousand lineal feet of their said tunnel, in one or more sections, should be completed. $ , , when thirty miles of their railroad, in one or two sections, and six thousand lineal feet of their tunnel, should be completed. $ , , when thirty-two miles of their railroad, in one or two sections, including all the line east of florida, and seven thousand lineal feet of their tunnel, in one or more sections, should be completed; and for each additional portion or portions of said tunnel of fifteen hundred feet, in one or more sections, completed by said company, $ , , subject to the condition that the last $ , should be reserved until said company, or their successors, should open their railroad for use from greenfield to the line of the state in williamstown; and subject also to the condition, that, prior to the second delivery of scrip, thirty per cent. of the same shall have been paid in cash to the treasurer of the company by the stockholders thereof, in addition to the $ , to be paid prior to the delivery of any scrip; and that upon each application for scrip, in pursuance of the law, and prior to the delivery thereof, thirty per cent. of the scrip then applied for shall have been paid by the stockholders to the treasurer of the company until the $ , subscribed for has been paid by the stockholders. the act further provided, that the treasurer of the company, within three months from the receipt of any scrip, should pay to the commissioners of the sinking fund created by the act, ten per cent. on the amount of scrip so taken as a sinking fund; and after the road should be opened for use, twenty-five thousand dollars should be annually paid to said commissioners for the same purpose. the act further provided, that the said company should execute an assignment, as a pledge or mortgage on the railroad, with its franchise property and income, conditioned to pay the principal sum of said scrip, or so much thereof as the sinking fund should be insufficient to pay, and the interest, as the same became due; and that said company should assign all the interest it then had, or might afterwards obtain, in the southern vermont railroad company. in , the legislature authorized certain towns on the line,--to wit: ashfield, buckland, conway, colrain, charlemont, deerfield, greenfield, hawley, heath, rowe, shelburne, adams, florida, and williamstown,--to subscribe three per cent. on their valuation, respectively, to the capital stock. this act was not fully complied with on the part of the towns, and $ , only is reported to have been realized from that source. in a contract with e. w. serrell to construct the work was reported to and accepted by the directors. this contract does not appear among the papers of the corporation, and its terms cannot be stated. at the same time the capital stock of the corporation was by a vote increased to $ , , , and a location designated as the east line on the railroad near cheapside was adopted. this singular resolution was also passed:-- _resolved_, that the direction of the engineering operations within the hoosac tunnel after the location of the line is adopted, and plans perfected for the same, be left with the contractor, excepting the measurements for monthly and final estimates and the final acceptance of the work. , july . mr. serrell having proposed to subscribe the sum of $ , (less the amount of the new subscription made by others,) provided the company would make such allowances as would enable him to dispose of the proposed issue of $ , of bonds advantageously, the directors voted to add $ , to the contract prices of the work, and that said $ , bonds as provided by the contract should be issued as soon as authorized by the stockholders, and placed in bank by the trustees to the credit of such persons as shall deposit against the same cash or railroad iron equal in value to sixty-five cents on the dollar. the said bonds to be taken by said serrell at par and so estimated in his contract. at this time sixteen hundred and thirty-five shares of new stock had been subscribed, amounting to $ , . the trustees alluded to in the foregoing vote were selected by a committee appointed for the purpose, and with power to execute to them a mortgage. they were j. v. c. smith, paul adams and john g. davis, all of boston. the mortgage was executed, and is known in the history of the road as the "smith mortgage." a resolution explanatory of this transaction was passed august , , in the following words:-- "_resolved_, that, whereas by the terms of the provisions of the resolution of july , , by which it is provided that the bonds of the company to be issued, are to be placed in bank, &c.; therefore, as explanatory thereto, be it _resolved_, that it is not intended thereby to prevent the operation of the contract, but that the said bonds are to be delivered to serrell & co., on the warrant of the engineer, countersigned by the president and treasurer, whenever the engineer shall draw therefore on monthly or final estimates." , february . the president reported to the directors that a contract had been redrafted and concluded with messrs. serrell, haupt & co., which was read, accepted and ratified, and the committee discharged. this contract was probably dated january , , but the committee have not been able to find it among the papers of the corporation. , may . the directors voted, that in case messrs. serrell, haupt & co., would enter into an agreement to carry on the work of the troy and greenfield railroad company, in compliance with the terms and conditions of the loan act, until , feet of the tunnel should be completed, the corporation would substitute bonds instead of stock in all payments to be made on account of work to be done to that time. the treasurer was authorized to give the acceptance or notes of the company, to an extent equal to the whole indebtedness of the company to said contractors, upon which to raise money to carry on the work. that the company would pay or allow to said contractors all discounts or losses to which they might be required to submit, provided such discounts or losses did not exceed the rate of per cent. per annum. that the trustees of the mortgage bonds should deliver to mr. herman haupt one hundred thousand dollars in the bonds of the company in addition to payments due for work, said bonds to be sold or hypothecated by him, and the proceeds applied to the work. the bonds to be charged on account of the contract if not returned when the second payment from the state shall have been made. , july . h. haupt and w. a. galbraith notified a dissolution of the firm of serrell, haupt & co., and proposed to enter into a new contract. e. w. serrell notified that messrs. haupt and galbraith were authorized to surrender the old contract. the stock subscription of edward w. serrell and e. w. serrell & co., was transferred to h. haupt & co., the latter to furnish a guarantee that the assessments due and to become due should be paid. e. w. serrell resigned his office as a director in the company, and was appointed consulting engineer. w. a. galbraith was chosen a director. , july . a contract was made with herman haupt, william a. galbraith, c. b. duncan and henry cartwright for the construction of the road and tunnel. the firm name of the contractors was h. haupt & co. by the provisions of the contract all work done under previous contracts with e. w. serrell or serrell, haupt & co., was to be credited to h. haupt & co., and all payments under said contracts were to be charged to h. haupt & co., and credited to the troy and greenfield railroad. "the road from the eastern terminus at or near greenfield from some convenient point on the vermont and massachusetts line, as the same now is or hereafter be located," is assumed to be in all about forty-two miles in length. "this contract includes the graduation, tunneling, masonry and bridging, superstructure, fencing, depot buildings, switches, turn-tables, water and fixtures, and in fine all labor and materials necessary for the construction of the road are included in this contract." the right of way to be provided and paid for by the railroad company. the work to be completed and finished in the best manner, for which the troy and greenfield railroad company agreed to pay h. haupt & co., "the sum of three millions eight hundred and eighty-three thousand dollars in manner following, to wit: two millions of dollars in the bonds of the state of massachusetts, to be issued under the act by which the credit of the said state is loaned to said corporation, nine hundred thousand dollars in the six per cent. mortgage bonds of said company, five hundred and ninety-eight thousand dollars in the capital stock of said troy and greenfield railroad company, and three hundred and eighty-two thousand dollars in cash." the work of constructing and completing the road was to be done in compliance with the loan act of april, . one hundred and fifty thousand dollars to be expended by the contractors in depot buildings and necessary rolling stock, cars, engines, &c. under the direction of the board of directors. the stock subscription of e. w. serrell and of serrell & co., amounting to five thousand nine hundred and eighty-seven shares, was to be transferred and assumed by haupt & co., payable in compliance with said loan act with the understanding that the assessments on the stock were to be paid by the performance of this contract in stock credits as provided in the contract, and the stock taken by the contractors at par. this contract further provided, that on the receipt of the several installments of state bonds, the contractors should pay to the sinking fund the ten per cent. specified in the loan act, in consideration of which haupt & co. should retain whatever sums was realized from the exchange and premium on the bonds. the payments were to be made monthly, on estimate of the company's engineer. the cost of the materials and work upon the line, exclusive of the hoosac tunnel and its approaches, was assumed to be one million eight hundred and eighty thousand dollars, and the estimates were to be made in the relative proportion that the part done bore "to the whole amount of materials and work to be furnished, and done at the price named." the hoosac tunnel and its approaches were estimated at two million dollars for a double track, and the monthly estimates were to be in proportion to the amount of work done on the approaches, and the length of tunnel excavated. the contract further provided, that, with the assent of both parties, the tunnel might be constructed for a single track, in which case no abatement was to be made for the first three thousand feet; but for the excavation beyond that point, the sum of twelve dollars per lineal foot was to be deducted from the contract price. the above are the essential provisions of the contract under which h. haupt & co. performed their work upon the road and tunnel until february , , except as the same was modified and changed by votes of the directors. the contract was reported to the board of directors, and approved by them august , . on the same day the directors voted to request the trustees to recognize h. haupt & co. as contractors, instead of e. w. serrell, and to issue the bonds to said h. haupt & co. on the estimate of the engineer and the order of the trustees. they also voted to change the location of the road at the west end, in accordance with plans marked a and b. under date of july , , there appears upon the records the following:-- a preamble, "stating that the efforts to raise money for building the road had proved unsuccessful; that no payments had been made the contractors for more than a year, * * * *; that the work could only be carried on by the continued efforts * * * * and personal credit of the contractors. "therefore voted, that the whole of the state bonds that may be issued in aid of the troy and greenfield railroad company shall be exclusively appropriated to work done, or to be done, upon the tunnel, in compliance with the terms and conditions of the act authorizing the loan of credit, and with such other conditions and modifications as the legislature may, from time to time, make and establish; but said h. haupt & co. shall not be held subject to any other conditions whatever, so far as respects the work done upon the tunnel; and any state scrip that may at any time be delivered to the treasurer of the company, shall be promptly handed to the contractors; the contractors, on their part, to comply with the conditions of the present act, and with such other conditions or modifications as may be introduced, and to have the benefit of any extension of time or increase of compensation by the state. second. any new or additional subscription that may be obtained, shall be applied to payment of the present contractors for work done, or to be done, by them, and to no other object; and any subscriptions that may be collected west of the hoosac mountain, shall be applied exclusively to the completion of that portion of the road. third. the present subscription east of the hoosac mountain may be collected and applied to the payment of other liabilities of the corporation, and the treasurer is requested to prepare, without delay, a full and complete list of all such liabilities. fourth. any commissions for procuring or collecting subscriptions shall be paid by h. haupt & co., in consideration of which, and also of the premises, the payment of graduation, masonry, bridging, and superstructure on the road, exclusive of the tunnel, shall be two million dollars, with the addition of such sums as may be required for the right of way, if this item shall be paid by the contractors. of this amount, nine hundred thousand dollars shall be in mortgage bonds of the company, and the balance in cash, to as great an extent as can be procured, the remainder in stock at par; and the directors of the troy and greenfield railroad company shall use their best endeavors to increase the cash subscriptions as much as possible. if new parties be introduced, or desired by h. haupt & co., the contract may be redrafted, and these conditions and changes incorporated; the committee for this purpose shall consist of the president and alvah crocker, with power to execute it finally, if not inconsistent with the present contract, or with the changes hereby authorized. it is further agreed and understood, that nothing herein contained shall be so constrained as to invalidate the existing contract with said haupt & co., or vary its conditions, except so far as herein expressed or necessarily implied." on the th of february, , another agreement was made by herman haupt and henry cartwright with the troy and greenfield railroad company, and such others as might be associated with them; and who upon signing the contract were to be considered as parties to the same; as it bears the signatures of d. n. carpenter, president for the troy and greenfield railroad company, and h. haupt & co., by h. haupt, and no others, it may be presumed that messrs. haupt and cartwright are the only persons comprising the party of the first part. this contract recites that every attempt to procure new or to collect old subscriptions to the capital stock of the company, since the execution of the former contract with h. haupt & co., have proved unsuccessful; that the contractors had prosecuted the work for more than two years without any payment having been made to them as required by existing contract; that there appeared no possibility of procuring means for the further prosecution of the work, except by the continued efforts, increased expenditures, and personal credit of the contractors themselves; and that h. haupt & co. propose to release the troy and greenfield railroad company from the cash payments required by the contract, and to assume themselves the labor of procuring and collecting subscriptions, and of carrying on and completing the troy and greenfield railroad and hoosac tunnel in such manner as will comply with all the conditions of the loan act. the parties therefore agreed. that h. haupt & co. should comply with all the conditions of the act, approved april th, , whereby a loan of credit was given by the state of massachusetts in aid of the construction of the hoosac tunnel, and should have the benefit of any changes that may hereafter be obtained, or extensions of time that may be granted; but they shall be subject to no other conditions or restrictions other than those expressed in this contract. that the road shall be so constructed that its gradients should not exceed those in each direction which exist or may hereafter exist permanently on other portions of the line between troy and boston; that sharper curves than were in ordinary use in other parts of the line were to be changed at the expense of the contractors, and trestle work or temporary bridging was to be replaced by permanent structures at the expense of the contractors as soon as practicable after the completion and opening of the whole line. that h. haupt & co. should have the benefit of all existing subscriptions, and of all they might procure; also of any revenue that might arise from the use of the road, or any portion of it when completed, until their claims on the company were discharged and paid; and to secure this end, the payment of all other debts of the corporation was to be deferred until that of the contractors was satisfied. the real estate of the corporation not required for the purposes and use of the road, was to be sold or applied to meet present liabilities of the company; and haupt & co. were to maintain the organization of the corporation and pay its necessary printing expenses, by paying to the treasurer annually a sum not less than five hundred dollars. the state bonds were to be appropriated exclusively to the construction of the tunnel. the state scrip delivered to the treasurer of the company was to be promptly handed to the contractors. the compensation to be allowed to h. haupt & co. was to be as provided in the resolutions of the directors, passed july , . the payment for graduation, bridging, masonry, and superstructure on the road, exclusive of the tunnel, was fixed at two million dollars, exclusive of any payments that might be made for the right of way. of this amount, nine hundred thousand dollars was to be paid in mortgage bonds of the company; the balance in cash, to as great an extent as cash subscriptions could be secured; the remainder in stock at par. the bonds and stock of the company to be issued to h. haupt & co. when required, to an amount equal to the work done, estimating it by the proportion it bore to the whole amount performed and to be performed. h. haupt & co. were authorized to collect subscriptions to the capital stock of the company, and their receipt for money was to be accepted by the company as evidence of payment. by the execution of this agreement all former contracts between the same parties were agreed to be annulled and cancelled. h. haupt & co. was recognized as the firm name under which the parties of the first part were associated, and then to be conducted. copies of this and the preceding contract will be found printed verbatim in a report of a committee of the house of representatives in , of which mr. kimball, of boston, was chairman. it was reprinted in , and is house document no. , of last year; and it may be profitably consulted for other valuable information touching the doings of the troy and greenfield corporation and the contractors therewith. , may , the directors assented that the iron delivered by the rensselaer iron company for the road should remain the property of the iron company until the same was paid for, in accordance with an agreement of h. haupt & co. with the iron company. from a report of a committee of the directors made to the board july , , it appears that at the date of the report, seven thousand four hundred and fifteen, shares were subscribed for unconditionally by parties who appeared to have been solvent at the time of subscribing. that three thousand four hundred and fifty shares had been subscribed for conditionally, or, by parties who were not solvent, or whose subscriptions could not be collected. that of the conditional subscriptions, the greater part had been or would be complied with; of these nine hundred and thirty-nine were subscribed by the towns not included in the published lists. upon two thousand four hundred and thirty shares of the unconditional subscriptions, including those of gilmore and carpenter, twenty per cent. only had been paid. that upon six thousand five hundred and nine shares, subscribed for unconditionally, twenty per cent. or more had been paid in cash. at this date it appears that the whole number of shares subscribed for conditionally and unconditionally, was ten thousand eight hundred and sixty-five. at this meeting of the board the clerk was directed to place upon the record the names of all the stockholders, with the number of shares held by each, on which twenty per cent. or more had been paid. the record shows the number of shares to be six thousand six hundred and forty-eight, and the amount paid on the same two hundred and sixty-seven thousand five hundred and sixty-nine dollars. against the name of h. haupt & co. was set the number of five thousand shares. at this meeting the directors also voted to fix the capital stock at one million five hundred thousand dollars. , september . the last vote was reconsidered, and it was voted that the capital stock be fixed at [note: amount missing] as represented by the list of stock reported at the previous meeting. the directors also voted as they had previously done, to rescind all the assessments heretofore voted, except the assessment of three per cent. laid april , , and then voted an assessment of ten per cent. upon each and every share in the capital stock of the company, payable in thirty days. between this date and september , , nine other assessments were voted, the whole amounting to eighty-eight per cent. of the par value of the stock. by another entry upon the records, under date of november , , it appears that williamstown and adams subscribed to the capital stock of the troy and greenfield railroad, ninety-three thousand dollars, upon condition that the payment should be made in town scrip, maturing in thirty years, and to be issued whim the road was completed between adams and troy; half the interest on the scrip to be paid by the troy and boston railroad company. mortgage bonds of the troy and greenfield railroad company, in amount equal to said subscription, were to be deposited in the adams bank as security against loss of stock from such a contingency as a sale of the road by the _bona fide_ holders. immediately following this entry upon the records are recorded these votes:-- _voted_, to accept the subscription on the condition stated, that the contract with the troy and boston railroad company be altered to allow said company to pay the interest on the scrip directly to the treasurers of the towns; that bonds to the amount of ninety-three thousand dollars be prepared ready for delivery, and that mr. haupt and the treasurer be a committee to carry this vote into effect, as also any change of contract with the troy and boston railroad company. _voted_, that the trustees of the mortgage bonds of this corporation be, and hereby are, requested to deliver to mr. h. haupt and the treasurer, ninety-three bonds of one thousand dollars each, to be deposited by them in the adams bank, in compliance with the conditions and requirements of the votes of towns of adams and williamstown, &c., &c.; sixty bonds to be appropriated as security for adams, and thirty-three for williamstown. under date of may , , appears the following record:-- whereas, satisfactory evidence has been afforded to the board of directors of the troy and greenfield railroad company that h. haupt has, by an instrument of writing, duly executed, formally relinquished, for himself, his heirs, executors and administrators, all pecuniary interest in any profits that may be realized in the construction of the troy and greenfield railroad and hoosac tunnel, and that the use of his name in connection with the firm is merely nominal, to avoid the inconvenience and embarrassment resulting from a change of title: _voted_, that in the opinion of this board, no impediment exists to prevent the said h. haupt from performing the duties of chief engineer of the troy and greenfield railroad company, and that he be, and hereby is, appointed to said office. , december . _voted_, that the treasurer be, and hereby is, directed to hand over to h. haupt & co., as soon as received by him, the bonds of the commonwealth, hereafter to be issued in aid of the road or tunnel, taking their receipt therefore. in , application was made to the legislature to reduce the size of the tunnel in order to facilitate its completion, and by chapter , of the acts of that year, it was provided that the tunnel might be constructed of the height of eighteen feet, and fourteen feet wide, and the payments were changed so as to depend upon the construction of the railroad, the excavation of the tunnel, and also of the heading, which was to be driven of the width of fourteen feet at the bottom, and the height of six feet in the middle, with a proviso that no more than seventeen hundred thousand dollars (in addition to the six hundred thousand dollars of scrip,) of stock subscriptions, and the anticipated scrip from the towns before, mentioned, all of which was to be considered as unconditional subscriptions, should be paid until the whole of the tunnel through the hoosac mountain shall have been completed, and the payments by the state were not to commence until twenty per cent. of the stock subscription should "have been actually paid in." the provisions of this act, in regard to advances by the state for progress actually made in excavating the tunnel and constructing the road, were substituted for those of the act of , the second section of which was repealed. by chapter of the acts of , the city of boston was authorized, with the consent of the legal voters, to subscribe five hundred thousand dollars to the capital stock of the troy and greenfield railroad; but the consent was not given. the legislation of did not meet the exigencies of the corporation, and application for assistance was again made. to relieve still further the difficulties of the company, the act of , chapter , was passed, in which it was provided that the undelivered portion of the loan of two million of dollars, authorized by chapter of the acts of , amounting to one million seven hundred and seventy thousand dollars, should be apportioned between the railroad and tunnel, and for the construction of each respectively, and six hundred and fifty thousand dollars was set apart for the completion of the unfinished portion of the railroad, extending from its eastern terminus, near greenfield, to within half a mile of the eastern end of the hoosac tunnel, and one million one hundred and twenty thousand dollars to the completion of the tunnel. the act provided for the execution to the commonwealth of such further bond and mortgage as the attorney-general should prescribe, and that such bond and mortgage, as well as all bonds, mortgages or other assurances heretofore made to the commonwealth by said company, should have priority and be preferred before any and all attachments or levies on execution heretofore or hereafter made. the act further provided that payments hereafter to be made for work done upon the road and tunnel, should be so made upon estimates of a state engineer, whose appointment and duties were prescribed in the act. such estimates were to be based upon a "width of road-bed, at grade, of fifteen feet on embankments, seventeen and a half feet in side cots, and twenty feet in through cuts; in the heading of the tunnel, upon dimensions fourteen feet wide and six feet high in the middle, and in the finished excavation of the tunnel, of fourteen feet wide and eighteen feet high in the middle." and the deliveries of scrip were to be at the rate of fifty dollars for each lineal foot of tunnel, divided between heading and full-sized tunnel, in the proportion of thirty dollars for each lineal foot of heading, and twenty dollars per lineal foot for the remaining excavation, and of six hundred and fifty thousand dollars for the whole of the graduation, masonry, bridging and superstructure of the road east of the tunnel. the weight of the rails was fixed at not less than fifty-six pounds to the lineal yard; the capital stock of the corporation at two millions and a half dollars, including all shares before issued. by the eighth section of the act the corporation was authorized to purchase the entire road franchise, stock, bonds, and other property or the southern vermont railroad company, together with its lease to the troy and boston railroad company, and subject to its provisions, for the sum of two hundred thousand dollars. this act repealed all prior legislation inconsistent with its provisions, with a saving of the security which the commonwealth had, by virtue of its mortgage on the franchise, railroad and property of the troy and greenfield railroad company, and was approved april , . , july . a committee was appointed to execute the mortgage to the commonwealth required by chapter , of the acts of . , july . the directors voted that mr. haupt be a committee to appear before the council in reference to the withholding the scrip now due the road; and january , , it was voted that mr. haupt be authorized to act as the agent and representative of the company in any relation that the company may be brought before the present legislature or any committee thereof. previous to the vote of july, , suspicion was excited that messrs. h. haupt & co. were not performing their work in a manner conformable to the requirements of the statute, and it was deemed imprudent to make any further advance of scrip under the act of , until the work was examined and the condition of the corporation better understood. an inquiry was instituted, a new state engineer appointed, and an investigation of the proceedings of the contractors and corporation was had. the facts disclosed in the examination induced the governor and council to withhold the issue of any more scrip, under the last mentioned law, and the legislature by chapter of the acts of , passed april , assumed the duty of completing the road and tunnel. the first section of the act is as follows:-- "the governor, with the advice of the council, is hereby authorized and directed to appoint three able, impartial and skilful commissioners, to investigate the subject of finishing the troy and greenfield railroad, and of tunneling the hoosac mountain, whose duty it shall be to report to the governor and council, what in their judgment, will be the most economical, practical and advantageous method of completing said road and tunnel; the estimated cost of fitting the same for use; the time within which the tunnel can be completed, and what contracts can be effected and with what parties for completing said tunnel and road and the probable cost of the same; the probable pecuniary value of the road and tunnel when completed; the sources and amount of traffic and income, and all other facts, in their opinion, useful to assist the governor and council in determining the best method of securing a continuous railroad communication between troy and greenfield." by the second section the troy and greenfield railroad company was authorized to surrender to the state the property mortgaged. by the third section the commissioners were authorized to audit and allow all just claims for labor, service, materials and land damages incurred between april , and july , , in carrying on the work, and to procure the release and discharge of all attachments and liens upon said materials. $ , was appropriated to pay the claimants under the approval of the governor and council. by the fourth section the commissioners were authorized to use or run that portion of the road east of the mountain or lease the same to the "vermont and massachusetts," the "fitchburg," the "troy and boston railway company," or either of them, until the completion of the tunnel. by the fifth section the commissioners were authorized to continue the work on the hoosac tunnel, and by contract or otherwise, to expedite its completion. on the th of august , is recorded on the records of the corporation the following votes:-- . "the directors of the troy and greenfield railroad company hereby instruct the president to transfer to the commonwealth of massachusetts, under the several mortgages held by said commonwealth, all the property of said corporation. . "_voted_ to call a meeting of the stockholders to see if they would ratify the above vote. . "_voted_, that the treasurer be directed to make no further delivery of the stock or bonds to the contractors without the written order of all the finance committee." at the commencement of the session of the legislature in january, , his excellency governor andrew, after stating the general provisions of the act of april, , and the appointment of the commissioners under it, "each of whom was carefully selected as being, in the words of the act, at once 'able, impartial and skilful,'" and after alluding to the labors of the commissioners, and the reports of the distinguished engineers appointed to "assist them, closes his remarks upon the enterprise in the following words:-- "the report of the commissioners to the governor and council is not yet made, but it is understood to be in rapid preparation. i am unable, therefore, to communicate to the legislature at the beginning of its present session so fully as i have hoped on the subject of this important and interesting enterprise of establishing a new avenue for our trade with the west, piercing the green mountain range, and opening up to greater activity the economical resources of our northern tier of towns. i trust that the conclusions and reasoning of the commissioners when published will settle conflicting opinions in the minds of the people, and, if favorable to the active pursuit of the enterprise, that its prosecution will enjoy an unanimous support. the work can be pursued, relieved from all factitious embarrassments, and contracts can be made by those in the sole interest of the commonwealth, superintended by citizens of the highest experience and capacity." in communicating the report of the commissioners to the legislature on the th of march, , after analyzing and commenting upon its statements and reasonings, the governor concludes his address in these words: "i congratulate thee general court and the people upon the rescue of the commonwealth, and especially of this great experimental enterprise, from a position inconsistent with economical, safe, or even possible success in piercing its mountain barrier. "i earnestly and respectfully invite your most candid and thoughtful consideration, not only of the specific facts and figures which elucidate or express the details of information bearing most immediately upon the work contemplated, but i also venture to commend to your deliberate judgment the arguments and reasonings drawn from liberal and enlightened views of public policy and of public economy, which finally lift this subject above all merely local interests or antagonisms into the sphere of statesmanship. and having attentively watched the progress of the report of the commissioners, and the documents by which it is accompanied through the press, i am prepared to give my own assent to the opinion with the expression of which the commissioners conclude their discussion:-- "'by the time the tunnel can be completed, the public interest requiring it will have grown large enough to pay for the outlay. the impulse given to business by the new facility, would soon fill up the new line, and make up the temporary loss felt by any other. "'considering the large sum which the commonwealth has already invested in this work, which must be sunk if it is not completed; the reasonable protection from loss which is offered by the other companies interested in the line; the more intimate relations it may promote between massachusetts and the west; and the benefits which such a facility promises to the city and state, we are of opinion that the work should be undertaken by the commonwealth, and completed as early as it can be with due regard to economy.'" the surrender of the road by the directors to the commonwealth, was followed by the following vote, passed january , :-- _voted_, that mr. stevenson, formerly state engineer of the troy and greenfield railroad, be requested to return an estimate of the payments and credits to which haupt & co. were entitled, under their contract, at the time of the suspension of the work, and that the amount allowed by such estimate be passed to the credit of h. haupt & co.; also, that the stock and bonds to which they are entitled be issued without further order, when legal impediments are removed. under the vote, mr. stevenson made the following report:-- _engineer's office, bunker hill bank building,;_} charlestown, mass., feb. , .} d. n. carpenter, esq., _president, pro tem., t. & g. r. r; co._ dear sir:--by a vote passed on the th of january last, i am requested to return an estimate of the payments and credits to which h. haupt & co. were entitled under their contract at the time of the suspension of the work on the troy and greenfield railroad. the contract thus alluded to recites that "the compensation to be allowed to h. haupt & co. shall be as provided in the resolutions of the board of directors of the troy and greenfield railroad company, passed july , a. d. , to wit: "the whole of the state bonds that may be issued in aid of the troy and greenfield railroad company shall be exclusively appropriated to work done, or to be done, upon the tunnel, in compliance with the terms and conditions of the act authorizing the loan of credit; and any state scrip that may,' at any time, be delivered to the treasurer of the company shall be promptly handed to the contractors. "the payments for graduation, bridging, masonry, and superstructure of the road, exclusive of the tunnel, shall be two millions of dollars, with the addition of such sums as may be required for right of way, if this item shall be paid by the contractors. of this amount, nine hundred thousand dollars shall be in the mortgage bonds of the company, and the balance shall be in cash, to as great an extent as cash subscription can be procured; the remainder in stock, at par. "the bonds and stock of the troy and greenfield railroad company shall be issued to h. haupt & co. whenever required, but not to a greater extent than they would be entitled to receive for the work done, estimating' it by the proportion which it bears to the whole amount done and to be done." this contract is so clear and precise in its terms that but one construction can be placed upon it, though it is evident that such terms were predicated upon a different state of affairs than existed at the time of suspension. by this contract, all state payments are to be exclusively appropriated to the work on the tunnel, while the stock and bonds are as exclusively devoted to the graduation, bridging, masonry, and superstructure of the railroad. the amount of compensation the contractors would thus be entitled to, is the issue of state scrip from july th, , to the time of suspension, and the $ , , of stock and bonds, less the amount required to finish the railroad. from this must be deducted such payments as may have been made from time to time, concerning which i have no data, but which your treasurer's books must show. any sums that may have been paid by the contractors for right of way, are to be added to the amount due. the cost of finishing the railroad must be estimated. for the road east of the tunnel, my estimate of the cost of finishing was, september , , $ , ; to this we should add one-half mile of railroad and bridge over the deerfield, $ , . for the unfinished portion west of the tunnel, i have no data of my own; i have, therefore, taken for the purpose the estimate of d. l. harris, which is the highest i can find--$ , . we thus have as the cash cost of completing the graduation, masonry, bridging, and superstructure of the road, $ , , which is to be deducted from the $ , , of stock and bonds, leaving the amount the contractors are entitled to, $ , , , less payments made, plus the amount of right of way, &c. this is in exact accordance with the strict construction of the contract which i previously have remarked was predicted upon a different condition of affairs than existed at the time of suspension. i deem it my duty in this connection respectfully to suggest whether, in view of the changes made in the issue of state scrip, which was paid upon the road as well as upon the tunnel, the contractors should not make proper reductions of the stock and bonds due them, taking into consideration as an offset to this such losses as they have been subjected to by the adverse action of the state authorities. this suggestion, however, is volunteered. my duty under the vote of the board is simply to decide what amount the contractors are entitled to receive under an exact and literal construction of the contract. l. stevenson, _civil engineer_. mr. haupt was present at the meeting of the directors at which the vote of january was passed, and the th day of may he addressed the following letter to the treasurer of the corporation:-- may , . w. t. davis, esq., _treasurer, &c._ dear sir:--i find the statement of payments on road in senate document, no. , , page communication of j. w. brooks to governor, viz:-- oct. , , $ , dec. , , , jan. , , , feb. , , , march , , , april , , , may , , , june , , , july , , , ----------- $ , omitting for the present any consideration of offsets, and deducting this whole amount for a temporary settlement, the items to be filled up will be as follows:-- whole amount of credit on road per stevenson's estimate, . . . . . . . . . . . $ , , deduct stock already issued as per certificates delivered, number, . . . . . . . . shares, . . . . . . . . . . . . bonds delivered, number, . . . . . . . dates of delivery, . . . . . . . . . total bonds and stock delivered, . . . . balance stock to be delivered, . . . . . in addition to this, h. haupt & co. have credits on the books of the company for cash payments made on company accounts as follows:-- * * * * * amounting to say, . . . . . . . $ , yours, &c., haupt. stock to be delivered hereafter instead of bonds. you can with these dates make out this statement in an hour, please do so and send to me at washington. some people in massachusetts will find out that i am not quite dead yet, they may feel me kicking before long. help field all you can to get releases on payment of the per cent. i will not forget you. haupt. previous to the receipt of mr. haupt's letter to the treasurer, but subsequent to the message of the governor, from the foregoing, extracts have been made, to wit: on the first day of april, , the following preamble and resolutions were passed by the directors. "on motion of mr. brigham, seconded by mr. cheever, the following resolutions were adopted:-- "_whereas_, the stockholders of this company at their annual meeting held september , , unanimously acquiesced in the action which the legislature had taken in regard to the affairs of this company, and voted to surrender the property of the corporation to the commonwealth in the expectation that the railroad and tunnel should be completed in conformity with the avowed intention of the legislature. it is "_resolved_, that this board of directors see no reason to regret the step which this corporation has taken, but in the kindly interest shown by his excellency the governor in this enterprise, and in the able report of the commissioners appointed to examine the subject, they perceive every indication that the great work will be prosecuted with vigor and arrive at an early completion. "_resolved_, that having released the property to the commonwealth, we recognize the state as having entire and complete control over the same; our only claim being that the state shall carry out in good faith the recommendations of the commissioners as contained in their report, and in the address of the chief magistrate of the commonwealth. "_resolved_, that the clerk be requested to furnish copies of the above vote to the friends of the road in the senate and house of representatives, to be used if necessary to show the views of the directors." on the th day of april, , the legislature, passed an act entitled "an act in addition to an act, providing for the more speedy completion of the troy and greenfield railroad, and hoosac tunnel," which is chapter of the acts of . by the provisions of this act, the commissioners appointed under chapter of the previous year, were authorized, subject to the advice and approval of the governor and council, to construct, complete and equip the troy and greenfield railroad and hoosac tunnel, and to make such alterations in the line of the road as may be deemed necessary to render it suitable and proper for part of a through line from troy to boston. also such alterations in the location and dimensions of said tunnel as will render it suitable and proper for use, in accordance with the spirit and intent of the th chapter of the acts of . by the legislation of and , and the vote of the directors and of the corporation in the same years, the corporation surrendered to the state the road and tunnel, and the state took possession of the same with the express understanding on both sides, that they would proceed in the construction and completion of both works. the enterprise having fallen into the hands of the state, and the work having been assumed by the state government, no further vote of importance appears upon the records of the directors. their last meeting was held august , , when alvah crocker was chosen president, and wendell t. davis, clerk and treasurer. [b.] _principal acts of the legislature relating to the hoosac tunnel and troy and greenfield railroad._ [ --chapter .] an act to incorporate the troy and greenfield railroad company. _be it enacted, &c._ sect. . george grennell, roger h. leavitt, samuel h. reed, their associates and successors, are hereby made a corporation, by the name of the troy and greenfield railroad company, with all the powers and privileges, and subject to all the duties, liabilities, and restrictions set forth in the forty-fourth chapter of the revised statutes, and in that part of the thirty-ninth chapter thereof relating to railroad corporations, and in all other general laws which have been, or shall be hereafter passed, relative to railroad corporations. sect. . said company are hereby authorized to locate, construct, and maintain a railroad, with one or more tracks, from some convenient point on the vermont and massachusetts railroad, at or near the termination of said railroad in greenfield, through any or all of the following towns, viz.:--greenfield, deerfield, conway, shelburne, buckland, coleraine, charlemont, hawley, rowe, and monroe, in the county of franklin, and savoy, florida, adams, clarksburg, and williamstown, in the county of berkshire, to some point on the line of the state of new york or of vermont, convenient to meet, or connect with, any railroad that may be constructed from any point at or near the city of troy, on the hudson river, in the state of new york. sect. . the said company may, with their railroad, unite with, and enter upon, the vermont and massachusetts railroad, at or near the termination thereof, as aforesaid, and may likewise enter upon, cross, and use, the railroad of the connecticut river railroad company, in and near the town of greenfield, (not, however, interfering with the depot buildings of either of said companies,) on such terms as may be agreed upon between the corporation hereby created and the aforesaid companies respectively, or as may be prescribed by law. sect. . the capital stock of the said company shall consist of not more than thirty-five thousand shares, the number of which shall, from time to time, be determined by the directors thereof; and no assessment shall be laid of a greater amount thereon, in the whole, than one hundred dollars on each share. and the said company may purchase and hold such real and personal estate, as may be necessary for the purposes of their incorporation. sect. . if the location of said road shall not be filed within two years, in the manner prescribed by law, or if the said railroad shall not be constructed within seven years from the passage of this act, then the same shall be void. sect. . the legislature may authorize any railroad company to enter, with their railroad, upon the troy and greenfield railroad, on such terms as may be agreed upon by said companies, or as may be prescribed by the provisions of law. sect. . the legislature may, after the expiration of five years from the time when such railroad shall be opened for use, from time to time, alter and reduce the rate of toll, or profits, upon said road; but said toll shall not be so reduced, without the consent of said company, as to produce, with said profits, less than ten per cent. per annum, upon the investments of the said company. sect. . the said corporation may contract with the owners of any contiguous railroad leading into or from either of the states of vermont or new york, for the use of the whole or any part thereof, or for the running and operating the two railroads conjointly, or for the leasing of such contiguous road, or for the letting or hiring of their own road to the owners of such contiguous road, or of any other road which composes a part of the railroad line between the cities of boston and troy, of which the railroad hereby authorized shall be a part. sect. . the troy and greenfield railroad company shall, within one year after the opening of their road for use, purchase and take an assignment of the lease and contract of transportation, made and executed between the western railroad corporation and the pittsfield and north adams railroad corporation, on the thirteenth day of january, in the year one thousand eight hundred and forty-six; and shall have all the advantages, and assume all the liabilities, accruing under and by virtue of said lease: provided, that the said western. railroad corporation shall perform their covenants in said lease, to keep said road, and other property therewith connected, in repair, until such assignment; and shall, within six months after the said troy and greenfield railroad company shall have filed the location of their road, according to law, and shall have raised, by subscription, one million of dollars, for the construction of the same, signify, in writing, their election to make such assignment: and provided, that, at the time of such assignment, there shall be secured to said western railroad corporation, by a proper instrument, a lien or mortgage upon all their rights in said pittsfield and north adams railroad, as collateral security for the performance of all the obligations of said corporation, contained in said lease and contract of transportation: and, provided also, that, after the completion of the said troy and greenfield railroad, the said western railroad corporation shall assign and convey, to the said troy and greenfield railroad company, the said contract of transportation, according to the terms of this section, if the said troy and greenfield railroad company shall so elect. sect. . this act shall take effect from and after its passage. [_may , ._ [ .--chapter .] an act concerning the troy and greenfield railroad company. _be it enacted, &c._ sect. . the troy and greenfield railroad company and the southern vermont railroad company, a corporation established by the laws of vermont, are hereby authorized by a vote of the stockholders now, or to be, passed, to unite themselves in one corporation; and such vote having been passed, they shall thereupon become one corporation, and all the franchises, property, powers, and privileges now enjoyed by, and all the restrictions, liabilities, and obligations imposed upon, said two corporations, by virtue of their respective charters, shall appertain to said united corporation in the same manner as if the same had been contained in or acquired under an original charter. such corporation, so formed by such union, shall be called by the name of the troy and greenfield railroad company. sect. . if the troy and greenfield railroad company shall unite with said southern vermont railroad company, then, and in that case, one or more of the directors of such corporation, formed by such union, shall be an inhabitant of this commonwealth, on whom processes against such corporation may be legally served, and said company shall be held answerable to answer in the jurisdiction where the service is made and the process returnable. sect. . the said company and the stockholders therein, so far as they are situate in massachusetts, shall be subject to all the duties and liabilities of railroad corporations in massachusetts, and to the general laws of this commonwealth in relation to railroad corporations. [approved by the governor, may , . [ .--chapter .] an act authorizing a loan of the state credit to enable the troy and greenfield railroad company to construct the hoosac tunnel. _be it enacted, &c._ sect. . the treasurer of the commonwealth is hereby authorized and instructed to issue scrip, or certificates of debt, in the name and in behalf of the commonwealth, and under his signature and the seal of the commonwealth, for the sum of two millions of dollars, which may be expressed in the currency of great britain, and may be payable to the bearer thereof in london, and bearing an interest of five per cent. per annum, payable semi-annually in london, on the first days of april and october; or the said scrip may be issued in federal currency, payable in boston, as the directors of the troy and greenfield railroad company shall elect when they apply for each and every issue of said scrip, with warrants for the interest attached thereto, signed by the treasurer; which scrip or certificates, in the currency of great britain, shall be redeemable in london, and those in the federal currency, at boston, at the end of thirty years from the date thereof, and the same shall bear date on the first day of april or october which shall precede the issue of each portion of said scrip; and all such scrip shall be countersigned by the governor of the commonwealth, and be deemed a pledge of the faith and credit of the commonwealth, for the redemption thereof; and the treasurer of the commonwealth, under the conditions hereinafter provided, shall deliver the same to the treasurer of the troy and greenfield railroad company for the purpose of enabling the said company to construct a tunnel and railroad under and through the hoosac mountain, in some place between the "great bend" in deerfield river, in the town of florida, at the base of hoosac mountain on the east, and the base of the western side of the mountain, near the east end of the village of north adams, on the west. sect. . whenever it shall be made to appear to the satisfaction of the governor and council, that the troy and greenfield railroad company shall have obtained subscriptions to their corporate stock, in the sum of six hundred thousand dollars, and twenty per cent. on each and every share of said six hundred thousand dollars shall have been actually paid in, and shall have completed seven miles of their said railroad, in one or two sections, and one thousand lineal feet of their said tunnel under the hoosac, in one or more sections, of size sufficient for one or more railroad tracks, a portion of said scrip, to the amount of one hundred thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have completed, in one or two sections, ten miles of their said railroad, and two thousand lineal feet of their said tunnel, in one or more sections, another portion of said scrip, to the amount of one hundred thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have completed fifteen miles of their said railroad, in one or two sections, and three thousand lineal feet of their said tunnel, in one or more sections, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have completed twenty miles of their said railroad, in one or two sections, and four thousand lineal feet of their said tunnel, in one or more sections, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have completed twenty-five miles of their said railroad, in one or two sections, and five thousand lineal feet of their said tunnel, in one or more sections, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have completed thirty miles of their said railroad, in one or two sections, and six thousand lineal feet of their said tunnel, in one or more sections, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have completed thirty-two miles of their said railroad, in one or two sections, including all their line to be constructed east of the town of florida, and seven thousand lineal feet of their said tunnel, in one or more sections, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered to the treasurer of said company; and for each additional portion or portions of said tunnel, of fifteen hundred lineal feet, in one or more directions, completed by said company, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered to the treasurer of said company; subject, however, to this proviso, that the last two hundred thousand dollars of said scrip shall be reserved until said company, their successors or their representatives, have opened said railroad for use through the hoosac, and laid a continuous railroad from greenfield to the line of the state in williamstown, when the same shall be delivered: provided, that prior to the second delivery of scrip to the treasurer of the troy and greenfield railroad corporation, according to the provisions of this section, evidence shall be furnished, satisfactory to the governor and council, that a sum, equal to thirty per cent. of the amount of the scrip then applied for, shall have been actually paid to the treasurer of said corporation; in cash, by the stockholders thereof, in addition to the hundred and twenty thousand dollars to be paid prior to the delivery of any scrip. and that on each application for scrip, in pursuance of the provisions of this section, and prior to the delivery thereof, satisfactory evidence shall be furnished to the governor and council, that a sum, equal to thirty per cent. of the amount of scrip then applied for, has been actually paid to the treasurer of said corporation, until six hundred thousand dollars subscribed for have been paid by the stockholders. and no scrip shall be delivered till satisfactory evidence of such payment is, from time to time, furnished to the governor and council. sect. . whenever the treasurer of said company shall receive any of said scrip, he shall, within three months from the receipt of the same, pay to the commissioners of the sinking fund, by this act hereafter established, ten per cent. on the amount of scrip so taken, as a sinking fund; after the whole of said road is open for us, twenty-five thousand dollars annually, shall be set apart from the income of said road and paid to said commissioners, and the whole thereof shall be added to said sinking fund, and shall be managed, invested and appropriated, as is, or shall be provided by law, in relation thereto. sect. . the treasurer of the commonwealth, the auditor of accounts of the commonwealth, and the treasurer of the troy and greenfield railroad company for the time being, shall be the commissioners of the sinking fund of the troy and greenfield railroad company. the said commissioners shall have the care and management of all the moneys, funds and securities at any time belonging to said sinking fund, and shall invest the same; but the moneys not invested, and all the securities of said fund, shall be in the custody of the treasurer of said commonwealth. sect. . this act shall not take effect until said company, at an annual meeting, or at a special meeting duly notified for that purpose, shall have assented to the provisions thereof, and shall have executed to the commonwealth a bond, in such form as the attorney-general prescribed on the issuing of scrip to the western railroad corporation, conditioned, that the troy and greenfield railroad company shall comply with the provisions of this act, and shall faithfully expend the proceeds of said scrip as herein provided, and shall indemnify and save harmless, the commonwealth, from all loss or inconvenience on account of said scrip, and that said company shall well and truly pay the principal sum of said scrip, punctually when the same shall become due and payable, or such part thereof as the sinking fund aforesaid shall be insufficient to pay, and the interest thereon semi-annually, as the same shall fall due, and shall also assign to the commonwealth, by suitable instrument or instruments, of the same form with that or those prepared by the attorney-general on the issuing of scrip to the western railroad corporation, the entire railroad, with its income, and all the franchise and property to them belonging, the whole thereof to be held by the commonwealth as a pledge or mortgage to secure the performance of all the conditions of said bond: _provided_, _however_, that the commonwealth shall not take possession of said pledged or mortgaged property, or any part thereof, under or by virtue of said mortgage, unless for some substantial breach of some condition of said bond. sect. . in addition to the security provided in the preceding section, the said company shall assign all the interest they now have, or may hereafter obtained, in the southern vermont railroad company. sect. . the troy and greenfield railroad company are authorized, and at any time prior to the execution of said mortgage, and within one year from the passage of this act, to alter the present location of their road: provided, that the tunnel shall be located and constructed within the limits prescribed by the first section of this act. sect. . the time for completing the troy and greenfield railroad is hereby extended, for the additional term of six years. sect. . when the commonwealth shall have advanced to said company, said bond or scrip to the amount of five hundred thousand dollars, the legislature may elect two directors of said company, who shall hold office for the same time, be elected in the same manner, and receive compensation to the same amount as the state directors of the western railroad corporation, but neither of them, while holding such office, shall serve as a director of any other railroad company. [_approved by the governor, april , ._ [ .--chapter .] an act to authorize certain towns in the counties of franklin and berkshire to subscribe to the capital stock of the troy and greenfield railroad company. _be it enacted, &c._ sect. . that each of the several towns of ashfield, buckland, conway, coleraine, charlemont, deerfield, greenfield, hawley, heath, monroe, rowe, and shelburne, in the county of franklin, and each of the several towns of adams, florida and williamstown, in the county of berkshire, be, and hereby is, authorized to subscribe for and hold shares in the capital stock of the troy and greenfield railroad company, to any amount of money not exceeding three per centum on the amount of its last valuation: provided, the inhabitants of such town or towns, at a legal town meeting duly called for that purpose, shall vote by a two-thirds vote to subscribe for such shares in accordance with the terms of this act, to pay for the same out of the town treasury, and to hold the same as town property, subject to the disposition of the town, for public purposes, in like manner as any other property which it may possess. sect. . said towns are hereby authorized to raise, by loans or taxes, any sums of money which shall be required to pay the instalments on their respective subscription to said stock and interest thereon. sect. . this act shall take effect from and after its passage. [_approved by the governor, may , ._ [ .--chapter .] an act in addition to, an act authorizing a loan of the state credit, to enable the troy and greenfield railroad company to construct the hoosac tunnel. _be it enacted, &c., as follows:_ sect . the terms of the act authorizing a loan of the state credit to enable the troy and greenfield railroad company to construct the hoosac tunnel, are hereby modified as follows, viz.: whenever it shall be made to appear to the satisfaction of the governor and council, that the troy and greenfield railroad company shall have actually obtained unconditional subscriptions to their corporate stock in the sum of six hundred thousand dollars, and twenty per cent. on each and every share of said six hundred thousand dollars shall have been actually paid in, and shall have completed seven miles of their road, in one or two sections, and one thousand lineal feet of their said tunnel under the hoosac mountain, in one or more sections, of size sufficient for one or more railroad tracks, a portion of said scrip, to the amount of one hundred thousand dollars, shall be delivered to the treasurer of said company; and whenever said company shall have, excavated, in addition to the amount of tunnel above provided for, one thousand lineal feet, in one or more sections, of heading or gallery of fourteen feet width at the bottom, and six feet in height in the middle, and of suitable proportion and form, or (if excavated by machinery) circular, and with a diameter of not less than eight feet, another portion of said scrip, amounting to fifty thousand dollars, shall be delivered to the treasurer of said company; and when said company shall have excavated two thousand feet of their said tunnel, of the size above specified, another portion of said scrip, amounting to thirty thousand dollars, shall be delivered as aforesaid; and whenever said company in addition to said two thousand feet, shall have excavated one thousand lineal feet of heading, in one or more sections, and of the size above specified, and shall have graded three miles of road, commencing on the bank of green river, at the present location of the crossing of said stream, or north thereof, and extending towards shelburne falls, on the same side of green river and deerfield river as the present location, said three miles being all situated within four miles of the point of commencement, another portion of said scrip, amounting to eighty thousand dollars, shall be delivered as aforesaid; and whenever in addition to the grading of said three miles as above, said company shall have excavated three thousand lineal feet of tunnel as above specified, another portion of said scrip, to the amount of twenty thousand dollars, shall be delivered as aforesaid; and whenever said company, in addition to the three thousand feet above specified, shall have excavated, in one or more sections, one thousand lineal feet of heading, as above specified, and shall have graded six miles of road in location and otherwise as aforesaid, said six miles of road being all situate within seven miles of the point of commencement at green river, another portion of said scrip, amounting to eighty thousand dollars, shall be delivered as aforesaid; and when said company, in addition to the grading of six miles of road above specified, shall have excavated four thousand feet of tunnel as above, another portion of said scrip, amounting to twenty thousand dollars, shall be delivered as aforesaid; and whenever said company, in addition to the above, shall have excavated, in one or more sections, one thousand lineal feet of heading as aforesaid, and shall have graded nine miles of road, in location and otherwise as aforesaid, between greenfield and shelburne falls, another portion of said scrip, to the amount of eighty thousand dollars, shall be delivered as aforesaid; and whenever said company, in addition to the above nine miles of graded road, shall have excavated five thousand feet of tunnel as aforesaid, another portion of said scrip, amounting to twenty thousand dollars, shall be delivered as aforesaid; and whenever said company shall have excavated, in one or more sections, one thousand lineal feet of heading as aforesaid, in addition to the five thousand feet of tunnel above specified, and shall have graded the road between greenfield and shelburne falls, crossing the green river upon the present location, or at a point north thereof, another portion of said scrip, amounting to eighty thousand dollars, shall be delivered as aforesaid; and whenever said company, in addition to the grading of the road between greenfield and shelburne falls as aforesaid, shall have excavated six thousand feet of tunnel as aforesaid, another portion of said scrip, amounting to twenty thousand dollars, shall be delivered as aforesaid; and whenever in addition to the grading and tunnel above specified, the said company shall have excavated as aforesaid, one thousand lineal feet of heading, another portion of said scrip, to the amount of thirty thousand dollars, shall be delivered as aforesaid; and whenever in addition to the grading above specified, the said company shall have excavated seven thousand feet of tunnel as aforesaid, another portion of said scrip, to the amount of twenty thousand dollars, shall be delivered as aforesaid; and for each additional thousand feet of heading that shall be excavated of dimensions as aforesaid, another portion of said scrip, amounting to thirty thousand dollars, shall be delivered as aforesaid; and for each additional one thousand feet of tunnel that shall be excavated of dimensions as aforesaid, another portion of said scrip, amounting to twenty thousand dollars, shall be delivered as aforesaid; and whenever said company shall have completed the graduation and superstructure of the road between greenfield and shelburne falls, on the route herein before specified, and shall have put the same in running order, another portion of said scrip, to the amount of forty thousand dollars, shall be delivered as aforesaid; and whenever said company, in addition to the road between greenfield and shelburne falls above specified, shall have completed the graduation and superstructure of two continuous miles of road, commencing at the western termination of the above road, another portion of said scrip, amounting to eighty thousand dollars, shall be delivered as aforesaid; and for the graduation and superstructure of each additional mile of road, graded and laid continuously through either of the towns of buckland, charlemont, rowe or florida, another portion of said scrip, amounting to twenty thousand dollars, shall be delivered as aforesaid: _provided_, that when the rails shall have been laid and the road put in running order, between greenfield and the east end of the hoosac tunnel, excepting that portion of the road which is to be made from the material to be furnished by the tunnel itself, another portion of said scrip, amounting to one hundred thousand dollars, shall be delivered as aforesaid: and _provided_, _also_, that whenever the aggregate amount of scrip that shall have been delivered to the treasurer of said company shall have reached the sum of one million seven hundred thousand dollars, no further delivery of scrip shall be made until the whole of the tunnel through the hoosac mountain shall have been completed, of size not less than fourteen feet in width and eighteen feet in height from the bottom to the top of the excavation, and until the facades of the said tunnel and such portions as may require arching shall be finished with good substantial stone or brick masonry, and until the rails shall have been laid over the whole length of the road, including the tunnel, and the same constructed in such manner, and the necessary connections with other roads finished, as will permit the convenient use of the same in the transportation of passengers and freight between the cities of boston and troy; but when such connections shall have been made, the tunnel fully completed and the road constructed as herein before provided, the balance of said scrip, amounting to three hundred thousand dollars, shall be delivered as aforesaid: and _provided_, _also_, that until the rails shall have been laid and the road put in running order between greenfield and shelburne falls, the aggregate payments under this act shall not exceed one million of dollars: and _provided_, _also_, that prior to the second delivery of scrip to the treasurer of the troy and greenfield railroad corporation, according to the provisions of this section, evidence shall be furnished, satisfactory to the governor and council, that a sum equal to thirty per cent. of the amount of the scrip then applied for, shall have been actually paid to the treasurer of said corporation, (in cash,) by the stockholders thereof, in addition to the one hundred and twenty thousand dollars to be paid prior to the delivery of any scrip, and that on each application for scrip, in pursuance of the provisions of this section, and prior to the delivery thereof, satisfactory evidence shall be furnished to the governor and council that a sum equal to thirty per cent. of the amount of scrip then' applied for, has been actually paid to the treasurer of said corporation, until the six hundred thousand dollars subscribed for shall have been paid by the stockholders; and no scrip shall be delivered until satisfactory evidence of such payment is, from time to time, furnished to the governor and council; and provided, also, no scrip shall be delivered to the treasurer of said corporation until satisfactory evidence shall be furnished to the governor and council, that said corporation have expended in a reasonable manner, in excavating and completing said tunnel, and in grading, constructing and completing the line of road, a sum at least equal to the amount of all the preceding issues of scrip. sect. . the preceding section of this act shall not be so constructed as necessarily to delay the opening of the road between greenfield and shelburne falls, until after the completion of six thousand feet of tunnel; but whenever any portion of not less than three miles of said road shall have been graded between greenfield and shelburne falls, as herein before provided, a portion of scrip, amounting to fifty thousand dollars, shall be delivered to the treasurer of the said company; and in case such payments shall have been previously made upon the road, the payments upon the completion of the third, fourth, fifth and sixth thousand feet of tunnel shall be reduced to thirty thousand dollars for each thousand feet of heading, and twenty thousand dollars for each thousand feet of tunnel of the required dimensions; but no portion of said scrip shall be delivered for any portion of said heading or tunnel, until the corresponding portion of the road shall have been graded as is herein before provided. sect. . whenever the treasurer of said company shall receive any of said scrip, he shall offer the scrip, received, to the treasurer of the commonwealth for sale; and if the treasurer of the commonwealth shall so require, being thereunto authorized by law, the treasurer of said company shall sell and dispose of the same to the treasurer of the commonwealth, at the fair market value thereof, to be determined by the governor and council. if the treasurer of the commonwealth shall decide to buy as aforesaid, then the treasurer of the company shall forthwith pay, to the commissioners of the sinking fund, ten per cent. on the amount of the scrip so taken, as a sinking fund. if the treasurer of the commonwealth shall decide not to buy, as aforesaid, then the treasurer of the company, within three months after the receipt of any of said scrip, shall pay to the commissioners of the sinking fund, ten per cent. on the amount of the scrip so received, as a sinking fund. after the whole of said road is open for use, twenty-five thousand dollars annually, shall be set apart from the income of said road, and paid to said commissioners; and the whole thereof shall be added to said sinking fund, and shall be managed; invested and appropriated, as is or shall be provided by law in relation thereto. sect. . the preceding sections shall be in lieu of and be substituted for sections two and three of chapter two hundred and twenty-six of the acts of the year one thousand eight hundred and fifty-four, and the second section of said act is hereby repealed. sect. . the time for completing the troy and greenfield railroad and hoosac tunnel, is hereby extended until december thirty-first, in the year one thousand eight hundred and sixty-five. sect. . subscriptions, the instalments upon which are payable in cash, or in the scrip of the towns authorized to subscribe to the stock of the troy and greenfield railroad company, under the provisions of chapter three hundred and ninety-four of the acts of the year one thousand eight hundred and fifty-five, shall be considered as unconditional subscriptions, in compliance with the requirements of this act; and payment in the bonds of said towns shall be considered as cash. sect. . this act shall take effect, whenever said company shall file, in the office of the secretary of state, a certified copy of any vote or votes accepting the same, which may be passed at any regular meeting of the stockholders of said company, or at any meeting specially called for that purpose. _approved march , ._ [ .--chapter .] an act in addition to an act authorizing a loan of the state credit to enable the troy and greenfield railroad company to construct the hoosac tunnel. _be it enacted, &c., as follows:_ sect. . the troy and greenfield railroad company shall forthwith make and file in the proper offices a location of their entire road and tunnel, which location shall be made on that side or sides of the deerfield river which will afford the most direct and eligible route between the village of shelburne falls and a suitable terminus in the town of deerfield or greenfield, to be determined by the state engineer appointed as hereinafter provided. the grades of any part of the road hereafter to be constructed shall not exceed forty feet to the mile ascending eastward, and fifty feet to the mile ascending westward; and the limits of grade and curvature of said road, included within said location; and not graded, shall be such that the maximum resistance to the passage of trains, in either direction, shall not exceed the maximum resistance in the same direction on the fitchburg and vermont and massachusetts railroads; and before any location made by the chief engineer of the troy and greenfield railroad company shall be filed, a copy of the alignment and a table of grades, verified by the oath of said engineer, shall be submitted to a state engineer appointed as hereinafter provided, who shall certify that the limits of grade and curvature herein before prescribed have not been exceeded, and the said table of grades so certified shall be filed with the location. sect. . no further deliveries of scrip shall be made to said company upon the conditions authorized in former acts, but the undelivered portions of the loan of two millions of dollars authorized by chapter two hundred and twenty-six of the acts of eighteen hundred and fifty-four, amounting to one million seven hundred and seventy thousand dollars, shall be divided and apportioned between the railroad and tunnel, and for the construction of each, respectively; six hundred and fifty thousand dollars for the completion of the unfinished portion of railroad extending from the eastern terminus of said road near greenfield to within half a mile of the eastern-end of hoosac tunnel, and one million one hundred and twenty thousand dollars for the completion of the tunnel, which shall be delivered upon the conditions and in the manner hereinafter declared, subject however to the provisions of the third section of chapter one hundred and seventeen of the acts of eighteen hundred and fifty-nine. no delivery of any portion of said scrip shall be made until said company shall, at a special meeting duly authorized for the purpose, have assented to the provisions of this act, nor until said company shall have duly made and located their line of road as aforesaid, and shall have executed to the commonwealth such further bond and mortgage, or other assurances of title on their franchise, railroad, or other property, as the attorney-general shall prescribe, for the further security of the commonwealth; and said bond and mortgage, and other assurances, and all bonds, mortgages, or other assurances heretofore made to the commonwealth by said company, shall have priority to and be preferred before any and all attachments or levies on execution heretofore or hereafter made. sect. . the governor and council shall annually appoint a state engineer for the purpose of examining and determining monthly the amount and value of the work done, and materials delivered on the railroad and tunnel of the troy and greenfield railroad company, who shall receive an annual salary of one thousand dollars, payable quarterly. the state engineer shall forthwith fix permanent marks in each end of the hoosac tunnel, marking the progress of the work up to february twenty-fourth, eighteen hundred and sixty, from which to determine the progress subsequently made. he shall also determine by suitable notes, marks, or observations, the amount and value of all grading, bridging, masonry, or other work done, or iron, or other materials delivered on the road east of the hoosac tunnel prior to december twenty-second, eighteen hundred and fifty-nine, and fix data from which to determine the value of any work, or materials delivered subsequent to the date last named. he shall monthly, immediately after the first day of each month, estimate the proportion which the work done upon the road, since the preceding estimate, bears to the whole of the work required to be done in the graduation, masonry, bridging, and superstructure of said railroad east of the hoosac tunnel, and also the work done in the excavation of said tunnel, which he shall certify separately to the governor, together with the amount of state scrip to which the company is entitled under the provisions of this act. such monthly estimates shall be based upon a width of road-bed at grade of fifteen feet, on embankments, seventeen and a half feet in side-cuts, and twenty feet in thorough-cuts; in the heading of the tunnel, upon dimensions fourteen feet wide and six feet high in the middle, and in the finished excavation of the tunnel of fourteen feet wide and eighteen feet high in the middle. the deliveries of scrip shall be at the rate of fifty dollars for each lineal foot of tunnel, divided between heading and full sized tunnel, in the proportion' of thirty dollars for each lineal foot of heading and twenty dollars per lineal foot for the remaining excavation; and of six hundred and fifty thousand dollars for the whole of the graduation, masonry, bridging and superstructure of the unfinished portion of the road east of the tunnel. the scrip shall be delivered on the road in the proportion which the value of the work done and the materials delivered each month bears to the estimated cost of the whole work and materials required on the portion of road aforesaid. no expenditures shall be required merely for the purposes of ornament, but the work shall be substantially performed, and the rails shall weigh not less than fifty-six pounds to the lineal yard; for any defective materials or work, a proportionate amount of scrip shall be withheld. the governor and council shall have a general supervision of the work, and for that purpose shall visit and inspect the same at least once in each year, and as much oftener as they may deem expedient; and they shall have power to correct abuses, remedy defects, and enforce requirements, by withholding scrip or imposing new requirements in such manner as the interest of the commonwealth shall in their judgment require. if the governor, upon the receipt of the monthly estimates and certificates of the state engineer, shall approve thereof, he shall transmit the same and his approval thereon to the state treasurer, and the state treasurer shall thereupon deliver the amount of scrip so certified for, to the treasurer of the troy and greenfield railroad company, or to his order, subject to the provisions hereafter mentioned. if he shall not approve thereof he shall submit the same to the council, and their approval transmitted to the state treasurer as aforesaid shall authorize such delivery. sect. . the company shall at least thirty days before any interest on any state scrip delivered to said company becomes payable, transmit the amount thereof, with costs of exchange, to the treasurer of the state, and he shall in all cases and at the charge of said company, pay at maturity all interest and costs of exchange which become payable on said scrip where the same is payable; and if said interest and exchange and all interest and costs thereon, or any payments required to be made into the sinking fund, or interest thereon, or any part thereof, remain unpaid when said company becomes entitled to the next delivery of state scrip, then the state treasurer shall deduct the amount so remaining unpaid, with all costs and interest thereon, from the amount of scrip then deliverable. sect. . the troy and greenfield railroad company may construct their railroad across the public highways at grade, in cases where the county commissioners of the county do not determine such manner of crossing to be detrimental to the public safety and convenience; but whenever they do so determine, said company shall construct the same in such manner as the county commissioners direct. sect. . the legislature shall immediately after the passage of this act, elect two directors of the troy and greenfield railroad company, to hold their office for one year, or until others are elected by the legislature; and any city, town or corporation that may subscribe not less than one hundred thousand dollars, shall have the right to elect annually one director; and any city that may subscribe not less than five hundred thousand dollars, shall have the right to elect annually by their council two directors in said company, which election may be held at any time after such subscription is made. sect. . the capital stock of the troy and greenfield railroad company shall consist of twenty-five thousand shares of the par value of one hundred dollars each, in which shall be included all shares heretofore issued or subscribed for, conditionally or unconditionally, or payable in work, an accurate account of which shall be made by the company, and recorded in the records of the directors. and the residue of said shares, and all shares which may revert to said company, shall be hereafter issued only at par value, and for cash, or town or city scrip, or for the bonds of the company. sect. . the troy and greenfield railroad company is hereby authorized and required to purchase the entire road, franchise, stock, bonds, and other property of the southern vermont railroad company, together with the income, benefits and reversion of its lease to the troy and boston railroad company, and subject to its provisions, for the sum of two hundred thousand dollars; and for the purpose of enabling them to make such purchase, and transfer the same to the commonwealth as additional security to the commonwealth for its whole loan, a further issue and loan of state scrip in federal currency; of the description specified in chapter two hundred and twenty-six, of the acts of the year eighteen hundred and fifty-four, is hereby authorized to be made, to the amount of two hundred thousand dollars, deliverable as follows, namely: whenever all the capital stock of the southern vermont railroad, excepting not exceeding twenty shares, of one hundred dollars each, and one hundred thousand dollars of its mortgage bonds, with coupons attached, the whole amount being one hundred and fifty thousand dollars, payable in twenty years from the date of issue, with six per cent. interest, payable semi-annually at the bank of commerce, in the city of new york, and the aforesaid lease of said company to the troy and boston railroad company, together with the rent reserved therein of twelve thousand dollars per annum, payable semi-annually, shall have been transferred to the treasurer of the commonwealth, for the future security of the commonwealth for its whole loan of credit to the troy and greenfield railroad company, in such manner as the attorney-general shall prescribe, and to the satisfaction of the governor and council, the state treasurer shall deliver one hundred and twenty-five thousand dollars of said scrip to the treasurer of the troy and greenfield railroad company; and when the remaining portion of said bonds, with the coupons attached, shall be in like manner delivered to the state treasurer, he shall deliver to the treasurer of the troy and greenfield railroad company the balance of said scrip, amounting to seventy-five thousand dollars: _provided_, that if any holders of said bonds, not exceeding ten thousand dollars in all, shall refuse to surrender the same at par, the troy and greenfield railroad company shall not be required to purchase the same, but the state treasurer shall withhold an equal amount of state scrip at par in lieu thereof. the semi-annual payments of the coupons, with the balance of the income from the lease of the southern vermont railroad, shall be collected by or paid to the state treasurer, who shall therefrom pay the interest on the two hundred thousand dollars of five per cent. scrip herein authorized to be issued, and shall pay the balance to the commissioners of the sinking fund of the troy and greenfield railroad loan, to be by them from time to time invested as is now by law required. the troy and greenfield railroad company shall, as soon as may be after the passage of this act, procure from the legislature of the slate of vermont the requisite authority for purchasing, holding and mortgaging to the commonwealth the franchise, railroad and property of the southern vermont railroad company, according to the provisions of this act; and in case such authority shall not be granted, and any want of security by reason thereof accrue to the commonwealth, the governor and council shall withhold from the troy and greenfield railroad company portions of scrip constituting the last deliveries to be made on the completion of the tunnel, to such amount, not exceeding two hundred thousand dollars, as may be required for further security. sect. . all acts and parts of acts inconsistent herewith, are hereby repealed: _provided_, _however_, that such repeal shall not, and nothing contained in this act shall, have effect or be construed in anyway to release or impair any security which the commonwealth now has or may hereafter have by force of the bond and mortgage now held by the commonwealth on the franchise, railroad and property of the troy and greenfield railroad company. _approved april , ._ [ .--chapter .] an act providing for the more speedy completion of the troy and greenfield railroad and hoosac tunnel. _be it enacted, &c., as follows:_ sect. . the governor, with the advice of the council, is hereby authorized and directed to appoint three able, impartial and skilful commissioners to investigate the subject of finishing the troy and greenfield railroad, and of tunneling the hoosac mountain, whose duty it shall be to report to the governor and council what, in their judgment, will be the most economical, practical and advantageous method of completing said road and tunnel, the estimated cost of fitting the same for use, the time within which the tunnel can be completed, and what contracts can be effected, and with what parties, for completing said tunnel and road, and the probable cost of the same, the probable pecuniary value of the road and tunnel when completed, the sources and amount of traffic and income, and all other facts in their opinion useful to assist the governor and council in determining the best method of securing a continuous railroad communication between troy and greenfield. sect. . the troy and greenfield railroad company is hereby authorized to surrender to the slate, the property now mortgaged; but the right of redemption shall not be barred until ten years have elapsed after said road and tunnel are completed and the same open for use. the said commissioners shall immediately, in the name of the commonwealth, take complete possession under the mortgages to the commonwealth, given by the troy and greenfield railroad company, of all property, rights and interests intended to be conveyed by said mortgages, or either of them, and then shall, without unnecessary delay, cause the said railroad to be completed and put into running order, and supplied with suitable depots, turn-tables and other usual and necessary appliances for the reception of freight and passenger cars, from the eastern terminus of the troy and greenfield railroad to the hoosac tunnel. sect. . said commissioners shall audit and allow all just claims for labor, service, materials, land-damages incurred after april sixth, eighteen hundred and sixty, and before july twelfth, eighteen hundred and sixty-one, in carrying on the work of constructing the troy and greenfield railroad and hoosac tunnel, and may procure the release of all attachments and discharge all liens on said materials. the accounts thus audited shall be transmitted to the governor, and, if approved by the governor and council, the governor is hereby directed to draw his warrant upon the treasurer in favor of the claimants, for the amounts thus allowed, to an amount not exceeding one hundred and seventy-five thousand dollars. sect. . said commissioners are hereby authorized, with consent of the governor and council, to use or run that portion of said road east of the hoosac mountain, or lease the same to the "vermont and massachusetts," the "fitchburg," the "troy and boston railroad company," or either of them, until the completion of the said tunnel. sect. . said commissioners shall have authority, with the approval of the governor and council, to continue the work on the hoosac tunnel, and by contract or otherwise, to expedite the completion of said tunnel. sect. . all the net earnings and income derived from said railroad, including the tunnel, shall be held by the commonwealth in trust: first, for the payment and reimbursement of the interest on all loans, advancements and disbursements of the commonwealth, on account of said railroad or tunnel: second, for the payment and reimbursement to all parties having a legal right thereto. sect. . the governor is hereby authorized to draw his warrant on the treasurer of the commonwealth, for such sums as may be required from time to time by the commissioners for the purpose of carrying out the provisions of this act, and the amount of the same is hereby appropriated therefore; and the treasurer of the commonwealth is hereby authorized to issue scrip, or certificates of debts, in the name and in behalf of the commonwealth, to an extent sufficient to secure the required funds, which scrip shall bear such rate of interest, as is allowed at the time on state scrip issued for other purposes, and shall be redeemable at the end of thirty years from the date thereof; and he shall sell or otherwise use the same at his discretion, to procure the sum necessary to meet the payments in this act provided: provided, that all expenditures and advances made under and by virtue of this act, shall be on account, and form part of the two millions of dollars, authorized to be loaned in state scrip to the troy and greenfield railroad company by chapter two hundred and twenty-six of the acts of eighteen hundred and fifty-four; and said expenditures and advances, together with all sums hitherto advanced to said company, excepting the sums advanced on account of the "southern vermont railroad," shall not exceed in amount the said two millions of dollars. such changes may be made in the location and grades of the road, as may be necessary to improve the same; and no lease shall be made of the portion of the road east of the tunnel for a term exceeding six years; nor shall such portion be constructed without the approval of the governor and council. sect. . all acts and parts of acts inconsistent herewith, are hereby repealed. sect. . this act shall take effect upon its passage. _approved april , ._ [ .--chapter .] an act in addition to "an act providing for the more speedy completion of the troy and greenfield railroad and hoosac tunnel." _be it enacted, &c., as follows:_ sect. . the commissioners appointed under the one hundred and fifty-sixth chapter of the acts of eighteen hundred and sixty-two, are hereby authorized, subject to the advice and approval of the governor and council, to construct, complete and equip the troy and greenfield railroad and hoosac tunnel; and to make such alterations in the line of said road as may be deemed necessary to render it suitable and proper for part of a thorough line from troy to boston; also such alterations in the location and dimensions of said tunnel as will render it suitable and proper for use, in accordance with the spirit and intent of the two hundred and twenty-sixth chapter of the acts of eighteen hundred and fifty-four. sect. . the governor is hereby authorized to draw his warrant on the treasurer of the commonwealth for such sums as may be required from time to time by said commissioners for the purpose of carrying out the provisions of this act, and the act or acts to which this is in addition; and there is accordingly hereby appropriated for the purpose of constructing and completing said tunnel and railroad and equipping the the same, and paying interest upon such scrip, as has been or may be issued during the progress of the work, the unexpended balance of the two millions of dollars authorized by chapter two hundred and twenty-six of the acts of the year eighteen hundred and fifty-four, and referred to in chapter one hundred and fifty-six of the acts of the year eighteen hundred and sixty-two. and the treasurer of the commonwealth is hereby authorized, upon the warrant of the governor drawn as aforesaid, to issue scrip or certificates of debt to the amount of said appropriation, which shall be expressed in such currency and shall bear such rate of interest as the governor and council may direct, and shall be redeemable at the end of thirty years from the date thereof: and said treasurer shall sell or otherwise dispose of the same as he may deem proper, subject to the approval of the governor and council. sect. . said commissioners', and their successors in office, shall be removable by the governor, with the advice of the council, and in case of any vacancy occasioned by death; resignation or removal, such vacancy shall be filled by appointment of the governor, with the advice of the council; and said commissioners shall, once in three months, and oftener if required, present to the governor and council an account of all contracts entered into by them as such commissioners, and of all payments and charges by them made, by virtue of their commission, with their vouchers therefore, which vouchers and accounts shall be examined, and if found correct, and in good faith, shall be allowed by the governor and council; but no lease of any part of said railroad, nor any contract amounting to more than ten thousand dollars shall be made by said commissioners without the of the governor and council. sect. . said commissioners in altering the location of the line of said road shall have the same power as railroad corporations have in making locations under existing laws, and may take, by purchase or otherwise, such lands, or easements therein, as may be needed for any purposes connected with the construction of said tunnel, and all titles or easements so taken shall vest in the commonwealth; and all parties aggrieved by any action of said commissioners, under this section, may have their damages assessed in the manner provided by law for the assessment of damages against railroad corporations; and all damages so assessed shall be paid from the treasury of the commonwealth to the party entitled thereto, upon the warrant of the governor, drawn pursuant to the provisions of this act. sect. . said commissioners, subject to the approval of the governor and council, shall have the power to use a part of the money appropriated by this act, not exceeding fifty thousand dollars, to extinguish any liens or claims, or rights of redemption which any person or corporation may have, in order to perfect the title of the commonwealth to said railroad and tunnel. sect. . the contract executed by the troy and boston railroad company, on the eighteenth day of february, eighteen hundred and sixty-three, by the vermont and massachusetts railroad company on the twentieth day of said february, and by the fitchburg railroad company on the twenty-third day of said month, printed on pages eighty-eight to ninety-four, inclusive, of the report of said commissioners made on the twenty-eighth day of february, aforesaid, and referred to in the message of the governor, dated the twelfth day of march, in the year eighteen hundred and sixty-three, is hereby approved, ratified and confirmed. sect. . the compensation or said commissioners shall be fixed by the governor, with the advice of the council; but the compensation of the chairman of said commissioners shall in no event exceed the sum of five thousand dollars per annum, nor shall the entire compensation of all of said commissioners exceed the sum of seven thousand dollars per annum. _approved april , ._ [c.] _statement of j. w. brooks, esq., chairman of the commissioners, made to the committee during the session of the legislature, ._ the first act for loaning the credit of the state to the troy and greenfield railroad company, dated april , , provides, besides other conditions, that when seven miles of the road in one or two sections is completed, and , feet of the tunnel, in one or more sections, sufficient for one or more tracks is completed, then $ , of scrip shall be delivered to the company. the size of the tunnel required by this act is not definitely stated, nor what proportion of the $ , of scrip is loaned on account of the tunnel. the act of april , , defines the size the tunnel to be feet wide and feet high. if this means excavation and not completed tunnel, then the room required for the ballast and drainage would reduce the height to about feet above the rails; a size absurdly small enough to be regarded as certainly not above the minimum intended by the act. the same act provides that $ per foot shall be allowed on account of heading, and $ on account of the enlargement, making $ per foot for the completed tunnel; $ , of the first advance may therefore be considered as on account of the first , feet of completed tunnel, and the remainder, say $ , , on account of the road which had been then completed west of the tunnel. the second delivery of scrip was on account of the tunnel, and under the provisions of the' act of , which provides that $ , may be advanced upon the completion of , feet of heading. the heading was done and $ , . delivered october , . the third delivery of scrip was under the provisions of the same act, and was on account of grading three miles of road, in detached pieces, near greenfield. for this, $ , . was delivered january , . the fourth delivery was under the same act, and for completing the second , feet of tunnel, for which $ , . , was delivered march , . an act changing the terms of the loan was passed april , . section divides the scrip remaining undelivered, as follows: "no further deliveries of scrip shall be made to said company upon the conditions authorized in former acts, but the undelivered portions of the loan of two millions of dollars authorized by chapter two hundred and twenty-six of the acts of eighteen hundred and fifty-four, amounting to one million seven hundred and seventy thousand dollars, shall be divided and apportioned between the railroad and tunnel, and for the construction of each, respectively: 'six hundred and fifty thousand dollars for the completion of the unfinished portion of railroad extending from the eastern terminus of said road near greenfield, to within half a mile of the eastern end of hoosac tunnel." section contains the following provisions: "the governor and council shall annually appoint a state engineer for the purpose of examining and determining monthly the amount and value of the work done, and materials delivered on the railroad and tunnel of the troy and greenfield railroad company, who shall receive an annual salary of one thousand dollars, payable quarterly. the state engineer shall forthwith fix permanent marks in each end of the hoosac tunnel, marking the progress of the work up to february twenty-fourth, eighteen hundred and sixty, from which to determine the progress subsequently made. he shall also determine by suitable notes, marks or observations, the amount and value of all grading, bridging, masonry, or other work done, or iron, or other materials delivered on the road east of the hoosac tunnel, prior to december twenty-second, eighteen hundred and fifty-nine, and fix data from which to determine the value of any work, or materials delivered subsequent to the date last named. he shall monthly, immediately after the first day of each month, estimate the proportion which' the work done upon the road, since the preceding estimate, bears to the whole of the work required to be done in the graduation, masonry, bridging, and superstructure of said railroad east of the hoosac tunnel; and also the work done in the excavation of said tunnel, which he shall certify separately to the governor, together with the amount of state scrip to which the company is entitled under the provisions of this act. such monthly estimates shall be based upon a width of road-bed at grade of fifteen feet, on embankments, seventeen and a half feet in side cuts, and twenty feet in through cuts; in the heading of the tunnel upon dimensions fourteen feet wide and six feet high in the middle, and in the finished excavation of the tunnel of fourteen feet wide and eighteen feet high in the middle. "the deliveries of scrip shall be at the rate of fifty dollars for each lineal foot of tunnel, divided between heading and full-sized tunnel, in the proportion of thirty dollars for each lineal foot of heading and twenty dollars per lineal foot for the remaining excavation; and of six hundred and fifty thousand dollars for the whole of the graduation, masonry, bridging, and superstructure of the unfinished portion of the road east of the tunnel. "the scrip shall be delivered on the road in the proportion which the value of the work done and the materials delivered each month bears to the estimated cost of the whole work and materials required on the portion of road aforesaid. "no expenditures shall be required merely for the purposes of ornament, but the work shall be substantially performed, and the rails shall weigh not less than fifty-six pounds to the lineal yard; for any defective materials or work, a proportionate amount of scrip shall be withheld. "the governor and council shall have a general supervision of the work, and for that purpose shall visit and inspect the same at least once in each year, and as much oftener as they may deem expedient; and they shall have power to correct abuses, remedy defects, and enforce requirements, by withholding scrip or imposing new requirements in such manner as the interest of the commonwealth shall in their judgment require." under the provisions of this act scrip to the amount of $ , . has been delivered on account of the railroad and $ , . on account of the tunnel. state scrip was delivered in sterling up to and including the delivery of march , , and afterwards in dollar bonds. in this statement the sterling is changed into dollars, to show it all in one currency, and the pound sterling is reckoned, as by the state treasurer when the deliveries were made, at $ . - / . the certificates for amounts due on account of the railroad or tunnel were for irregular sums, and the scrip delivered was in round amounts; the fractional difference sometimes in excess and sometimes below the amount of the certificates is divided between the tunnel and railroad in proportion to the amount due on account of each. stated and divided as above, the scrip which has been delivered on account of the railroad and tunnel, is as follows:-- ========================================================================= | | on account | on account of| date. | on account | of road west| road of east | total. | of tunnel. | of tunnel.| of tunnel. | ------------------+------------+-------------+--------------+------------ , october, , | $ , | $ , | - | $ , , october , | , | - | - | , , january , | - | - | $ , | , , march , | , | - | - | , , october , | , | - | , | , , dec. , | , | - | , | , , january , | , | - | , | , , february ,| , | - | , | , , march , | , | - | , | , , may , | , | - | , | , , june , | , | - | , | , , july , | , | - | , | , +------------+-------------+--------------+------------ |$ , | $ , | $ , | $ , ========================================================================= the amount of state scrip which according to statutes, had been earned by the progress made towards constructing the tunnel before the surrender of the property to the state, may be stated as follows:-- strictly considered, no portion of the tunnel at the east end was cut to the required size of feet wide and feet high, much of it was less than feet wide, and some of it only about feet high. at the entrance the excavation was so nearly sufficient that only a small amount more was required to bring it to full size, and had all the rest been well done, a not very exacting inspector might have passed feet of this as completed. the remaining , feet of penetration at this end could form no ground whatever for a claim as completed work. at the west shaft the heading had been driven in both directions - / feet. at the west end the total penetration had been feet. of this distance feet had been arched with stone-- feet is in rock, standing without support, and feet is temporarily supported with timbers. under the assumption that the feet left unsupported is safe enough to be left permanently , then feet was completed at this end, giving at all points a total penetration of , - / feet, of which, feet was completed. it is clear that the payment of $ , , under the act of april , , for , feet of completed tunnel, was not earned. under the act of , scrip to the amount of $ , was to be delivered upon the completion of , feet of heading, and though the prior conditions of this act had not been complied with, this amount may fairly be considered as having been earned. the next payment of $ , . for the completion of the second , feet of tunnel was clearly not earned. all subsequent payments were made under the act of april , , providing for the payment of $ per foot for heading and $ per foot for the enlargement. the total amount according to the several acts is as follows:-- under the act of ,-- for , feet of heading, $ , under act of ,-- for balance of heading, say , - / feet, at $ per foot, , for feet of enlargement, at $ per foot, , ----------- total amount earned, $ , the amount of state scrip which under the statute had been earned by the progress made in constructing the railroad may now be considered. the first payment of $ , under the act of , should have been for seven miles of completed railroad. the certificate of the engineer, upon which it was paid, gave (see page of house document no. for ,) the length of rails laid as upwards of seven miles; nothing in the certificate showed then any part of it was completed road, and upon investigation then made it proved that while most of it was done, a part near the west end of the tunnel "was not ten feet wide," and would cost several thousand dollars to complete it. it is clear that this payment had not then been earned in the manner provided by the statute. the second payment was on account of the road, under the act of , for grading three miles of road, "said three miles being all situated within four miles of the point of commencement;" page of house document no. for says of this grading, "the continuous line is interrupted by fourteen gaps of cuts and fills;" it is thus made up of fifteen separate pieces, avoiding all but the cheapest part of the work, and costing, as the contractor who did the work certifies, between $ , and $ , . under, to say the least, a somewhat liberal construction of the act, $ , was said to have been earned by doing this grading. all further deliveries of scrip have been under the act of , which provides that the $ , to be delivered on account of the road east of the tunnel shall be in proportion to the progress made upon the work. on page , (senate document no. for ,) the cost of the work done and materials furnished upon the road east of the tunnel is stated at $ , deduct amount first expended, as testified by the contractor, for which the $ , was paid, say , amount expended under the $ , appropriation, including the cost of worthless bridging and masonry, $ , the cost of completing the grading, bridging, masonry and superstructure upon this part of the road, as estimated by mr. laurie in , was $ , deduct the cost of a small change in the line, and of embankment washed away by the deerfield river, , sum required to complete the road upon the old line where the work stopped, $ , amount already expended under the $ , appropriation, , amount expended and to be expended at the then prices, $ , of which per cent. had been done when the work stopped, in july, . - / per cent. therefore of the $ , had been earned, and this amounts to $ , the total amounts earned and paid compare as follows: amount paid upon the tunnel, $ , amount paid upon the road west of the tunnel, , amount paid upon the road east of the tunnel, , ---------- $ , amount earned upon the tunnel, $ , amount earned upon the road west of tunnel, (not fully earned,) , amount earned upon the road east of tunnel, (temporary work included,) , ---------- , ----------- $ , overpayment in reckoning sterling exchange, say , overpayment when the work stopped, in july, , $ , ----------- further payments made upon the same work under the law of , , ----------- total amount paid more than earned, $ , if proper deductions had been made from the amount earned on account of the unfinished condition of the seven miles west of the tunnel, on which the first $ , was paid, and on account of the worthless masonry and bridging which have been reckoned in at full cost, the overpayments would be shown more correctly to exceed in amount the sum of $ , . * * * * * transcriber's notes: all obvious typographical errors were corrected. tables containing decimal fractions were standardized to show decimals for all values in the column. spelling was standardized to the most prevalent form. punctuation was left as printed. on page the curve value - / ° was changed to ° ' to match the other similar values. the sum of the shares in the table in appendix a on pages - should total , shares but was printed as , . this was assumed to be a typographical error. transcriber's notes the fractions one half and three quarters were shown respectively as - and - which was retained herein. +=========================+ | | | facts and figures | | | | | | | | concerning | | | | | | | | the hoosac tunnel. | | | | | | ----------- | | by john j. piper. | | ----------- | | | | | | fitchburg: | | | | john j. piper, printer. | | | | . | | | +=========================+ facts and figures concerning the hoosac tunnel. by john j. piper. fitchburg: john j. piper, printer. . the hoosac tunnel. in his inaugural address to the legislature, governor bullock says, "there can be no doubt that _new facilities_ and new avenues for transportation between the west and the east are now absolutely needed. our lines of prosperity and growth are the parallels of latitude which connect us with the young, rich empire of men, and stock, and produce lying around the lakes and still beyond. the people of massachusetts, compact, manufacturing and commercial, must have more thoroughfares through which the currents of trade and life may pass to and fro, unobstructed and ceaseless, between the atlantic and the national granaries, or decay will at no distant period touch alike her wharves and her workshops. let us avert the day in which our commonwealth shall become chiefly a school-house for the west, and a homestead over which time shall have drawn silently and too soon the marks of dilapidation. any policy which is not broad enough to secure to us a new england, having a proper share in the benefits of this new opening era of the west, be assured, will not receive the approval of the next generation." this important recommendation is what the public had reason to expect from a man so keenly alive to the interests and welfare of the commonwealth as governor bullock, whose close observation and discernment had long since discovered the danger, and disposed him to take a deep interest in any adequate enterprise by means of which it could be averted. the reasons which have induced his excellency's convictions on this subject, and caused the apprehensions he has expressed, are very clearly set forth in the following articles from the buffalo commercial advertiser of november th and th, :-- "to-day, the western states are far more bountifully provided with avenues of transportation than the extreme east. this is peculiarly anomalous and inexplicable when we consider the boasted enterprise, wealth and shrewdness of new england, and the dependence which always exists upon the part of a manufacturing district toward that section which furnishes it with a market, and from which it obtains its breadstuff. it is fortunate for new england that it does not lie in the line of transit between the west and _its_ market, or it would have drawn about its head a storm of indignation which it could not have resisted. the state of new york has contributed an hundred fold what new england has towards providing the required facilities of traffic, for the great west. our yankee friends have done much toward facilitating intercommunication among themselves, but very little toward direct communication with the west. it is not a little strange that, with all the ambitious effort of boston to become a mercantile emporium, rivaling new york, and with its vast manufacturing interest, it should have but a single direct avenue of traffic with the west. yet such is the fact. the western railroad between albany and boston is the sole route now in existence except those circuitous lines via new york city or through canada. our down-east friends, usually so keen and enterprising, seem to have exhausted their energies in the construction of that road twenty-five years ago, and the consequence is that to-day the business interests of all new england are suffering for lack of the timely investment of a few millions. strange as it may seem, it is nevertheless true that boston is now virtually cut off from its trade communication with the west for want of facilities of transportation. for weeks past the grand trunk railroad has ceased to take boston freight, by reason of its being blocked up with other through and way freights at sarnia. the swollen tide of freight via the new york central has exceeded the capacity of the western road between albany and boston, and the consequence has been felt in an increased charge by the new york central of twenty cents a barrel above new york city rates, and, finally, that road has been obliged to refuse boston freight altogether, simply by reason of the accumulation and delay occasioned by the inability of the western road to forward it to its destination. in like manner, boston freight going forward by canal is hindered and accumulated at albany. a similar state of things exists in regard to most of the westward bound boston freight, as boston jobbers are finding out to their cost. merchants at the west, who purchase in boston, are six and eight weeks in getting their heavy goods. we are informed upon reliable authority that flour can be sent from chicago to new york, by lake and rail for $ . per barrel, while very limited quantities only can be sent to boston at $ . , and that by the "red line" $ a barrel is demanded. new england depends upon the west for its bread, and also for its market for its imports and manufactures. if the state of things to which we refer, continues much longer, it will be compelled to go to new york both for its bread and its customers. the west complains of new york, because, forsooth, it is tardy in enlarging its canals to meet the anticipated necessities of its future growth, and boston has had the assurance to join in the thoughtless and unfounded clamor. yet the great state of massachusetts has supinely stood still for twenty-five years without making an effort to overcome the barrier between it and the great west. during that time the western road has grown rich, and paid large dividends from a business which has been greater than it could transact, and to-day there exists an almost total blockade of boston freight at albany. surely, this does not reflect favorably on new england shrewdness and enterprise, neither does it tally with new england interest. besides, it is detrimental to the business interests of the west. as the case now stands the fault rests with massachusetts alone, in not providing railroad accommodations east of the hudson river. it is also nonsense to assert, as some will, that the capacity of the erie canal is inadequate. during the past season it has not been taxed to half its capacity, and yet it has found the western road unable to dispose of what boston freight was offered. western merchants and shippers ought to know where the fault lies, and to the end that they may be informed we have penned this article. their true remedy is to buy in new york, and to ship their produce to that city, until massachusetts shall provide adequate facilities of transportation. boston is the natural eastern terminus of the great northern line of transportation, and we should have been glad to have seen her citizens and those of the great state of massachusetts realize the fact. their supineness, however, has lost to them for the present, if not forever, the great commercial prize which nature intended for them. it remains to be seen whether they will realize their position, and make an effort to retrieve their "penny wise and pound foolish policy." * * * * * "in a recent article we took occasion to point out the importance to the country at large of the construction of adequate facilities for the accommodation of the traffic exchanges between the different sections; and to call the attention of our readers to the remarkable fact that while the whole country, and particularly the west, had undergone a wonderful development requiring for its accommodation a corresponding increase of commercial facilities, that new england had stood still for a quarter of a century. the fact that a great state like massachusetts, with a great emporium like boston, should have but a single line of direct communication with the west, and that it should supinely stand still and refuse to add to it, notwithstanding the yearly demonstrations of its growing inadequacy, seemed so strange as to justify remark. the other fact that the transit of freight to and from boston should be almost stopped by the inability of that single railroad to handle it--thereby increasing rates and compelling purchasers as well as sellers to go to new york--also seemed to be inconsistent with our traditional ideas of eastern shrewdness. our remarks have received additional force by the fact, subsequently learned by us, that there are at the present time between four and five hundred car-loads of boston-bound freight lying at albany and greenbush awaiting cars for its movement to its destination, while there exists no stoppage whatever of new york freight, thus demonstrating clearly the inadequacy of the western road to answer the demands made upon it. since that article was penned, information has reached us to the effect that our massachusetts neighbors have at last waked up to the importance of the subject, and are about to enter vigorously upon the work of providing another avenue of trade between boston and the west, by what is known as the greenfield route which embraces the long talked of hoosac tunnel. this great enterprise has enlisted the energies of the engineers and railroad men of massachusetts for more than thirty years, with constantly varying prospects of success, and at last seems in a fair way of being accomplished. the high range of hills which runs along the whole western line of massachusetts, for a long time baffled the efforts of railroad engineers; and the rival claims of competing routes distracted the popular mind, and delayed the construction of either. the most eminent engineers preferred the northern, or greenfield route--involving the hoosac tunnel--as being the most direct and feasible. in the struggle which followed, the southern route was successful, and the western road was built and opened in . the other route was also constructed after a time, upon either side of the proposed tunnel, but for lack of the completion of that great work, has never been anything but an avenue for local travel and traffic. the whole length of the proposed tunnel is , feet, and the estimated cost of construction is about three and a quarter millions. when we consider the vital interest which the citizens of massachusetts have in the completion of this work, and the enormous interests to be served by it, the sum required seems absolutely trivial, and the withholding of it really parsimonious as well as foolish. we are pleased to learn that the state is at last about to lend a helping hand to this great enterprise, which will guaranty its speedy completion. this is an indication of wisdom upon the part of our neighbors, albeit it comes somewhat tardily. almost all the other states that lie between the great west and the ocean have pursued a very different policy from that of new england, and with very favorable results. new york, which was the pioneer in the matter of internal improvements, not only built her great canals, at a cost of over $ , , , but also aided largely in the construction of her great through lines of railroads. it contributed to the erie road $ , , , which is now seen to have been a good investment despite the fact that it was entirely lost to the state. the same policy was pursued by pennsylvania and maryland, with equally happy results. we congratulate our new england neighbors, and, especially, the citizens of boston, upon the improved prospect of the completion of the hoosac tunnel, and the opening of another great route to the west, through, instead of over the mountains which lie between them and us. we trust that the obstructions which have existed, and still exist, in the channels of commercial intercourse between new england and the west will speedily be removed, never again to be manifested in freight blockades or threatened diversions of trade." the statements contained in these two articles are substantially true; and they are not only interesting, but important, as throwing much light upon a subject which will, doubtless, occupy much of the attention and time of the legislature: for the western railroad managers have already opened their annual attack upon the hoosac tunnel, through their well known agents and tools, bird, harris and seaver, who shamelessly advocate the entire abandonment by the state of an enterprise to the completion of which her word, and bond, and honor are irrevocably pledged. the western railroad company was organized in january, , and its road was completed in , having received aid from the state, during the period of its construction, to the amount of five millions of dollars. the terms upon which state aid was granted were very liberal, as they should have been; for the opening of this line of road had become as much a necessity to the development of the commercial and industrial interests of massachusetts and the wants of her whole population, as the establishment of schools and churches had ever been to her moral or educational welfare. the involvement of the state in so great an enterprise was strenuously resisted by timid and narrow minded legislators; but the representations of those sagacious and far seeing men who had devoted themselves to the work, prevailed, and massachusetts was, thus early in the history of railroads, committed to a policy which has, within a few years, not only trebled her productions and wealth, but made her the first and foremost of all her sister states which are honored for enterprise, prudence and wisdom. many of the short sighted legislators, who voted against granting state aid to the western railroad company are now living, but we doubt if one can be found who is not ashamed of his action. the increase of business over the western road since the first year of its operation, would seem incredible, were it not so thoroughly established by the figures of its early and later annual reports. yet, with a double track nearly to albany, and every means which ingenuity can devise, or money procure, at their command, its managers are unable to meet the demand upon it--its _capacity_ is _nearly exhausted_--and _was_, long ago, so great is the pressure against our western border, from the overflowing granaries of the west. from a feeble association, begging for assistance at the doors of the state house, the western railroad company has become a powerful corporation. its certificates of stock, which, about the time the road went into operation, were a drug in the market at $ , now command $ to $ . yet it is a fact that on the first day of last november, five hundred car loads of freight were delayed at albany, and could not be transported over the western road in less time than ten days. and the inability of this road to meet our public needs, and the demands made upon it, from the west, is no new thing; it has been so, _for years_, though four competing lines have opened since , which, together, transport about the same amount of through freight as the western road. the bridge over the hudson at albany, the completion of the double track, and better management might afford a temporary and partial relief. but if these improvements had been already effected, they would not have prevented the freight blockade at albany last fall. should our friend of the salem gazette, or any of the editors who quote mr. f. w. bird, and write short paragraphs, more flippantly than intelligently, about the hoosac tunnel, chance to be at the freight yard of the fitchburg railroad in charlestown, on the arrival of a train of new york central railroad cars, laden with flour, grain, or other products of the west, he would doubtless be as much puzzled to know how they got there, as he would be, if, standing at the heading of the tunnel, he should endeavor to reconcile his situation (half a mile from daylight) with the calculations, statements and predictions of mr. bird and other opponents of the tunnel enterprise. if our friend were set down at the freight depot of the worcester and nashua railroad, in worcester, he would again be surprised to witness the arrival of freight-laden cars, bearing the same mark as those he saw at charlestown. upon inquiry of the freight agents he would learn that freight for boston and worcester, is transported from schenectady, over the washington and saratoga road, and from troy, over the troy and boston and western vermont, to rutland, vt., and thence, by the rutland and cheshire roads to fitchburg, and from there to boston and worcester over other roads. by glancing at a map the intelligent reader will at once observe what a circuitous and lengthened line of communication between the new york central road and the cities of boston and worcester is furnished by the connecting roads above named. the distance from schenectady to boston via rutland is miles, while it is but by way of the western road. the distance from the same point to worcester by the rutland route is miles, and by the western road only . yet because the western road has not capacity to do the business, the produce dealers of eastern and central massachusetts are compelled to resort to this roundabout way of transportation as one of their means of relief. but this is not the only channel, nor the most indirect, which the irrepressible stream of western trade with the east has created, as it approaches its natural outlet, boston; as the mississippi, scorning the narrow embouchure which satisfied its youthful flow, now pours its resistless torrents, through numerous passes to the gulf. besides that already described, there are three other lines competing with the western road in the transportation of western freight to boston. these are the grand trunk, the ogdensburg, and the providence and erie. few persons know that cotton from st. louis, for supplying the mills of lowell and lawrence, is unladen in boston from vessels which received their cargoes at portland, but such is the fact, the cotton having been transported over the great western and grand trunk roads. but these four long, and indirect lines, with their single track, are in the frame situation as the western road; _their_ capacity is exhausted, so far as through freight is concerned, this part of the business of all the four hardly exceeding that of the western road. to prove the utter incapacity of these five lines of communication between us and the west, to supply our wants, and meet the demands made upon them, we need only state the fact that in november and december last, many of the produce dealers and grocers _in worcester_, were unable to supply their customers, on account of the detention of freight at albany, detroit and ogdensburg. we may add, by way of illustration, that the immense loss of property occasioned by the burning of a large freight depot at detroit, and by which so many new england consignees severely suffered, was one of the incidental consequences of the incapacity of these lines of new england railroads to do the work required of them. we shall have occasion to consider further the capacity of the western railroad, but the facts already given are sufficient to show the necessity of opening another through and direct route from the hudson to boston. the next question to be considered, if, indeed, there can be any question about it, is how shall the new route be located? we have shown that another is necessary in order to accommodate through business, to meet the demands of the west, and to promote the prosperity of the entire state. but this is not by any means the whole argument. central and southern massachusetts are covered with a net work of railroads, from cape cod bay to the new york border, yet northern massachusetts, from fitchburg westward, has but a single road, and that terminating at greenfield, nearly forty miles from north adams, where the broken line of communication is again taken up. hence it is, that, while villages have become large towns, and towns populous cities, all over the rest of the state, this section has remained comparatively undeveloped; and the whole tier of towns lying along the line of the vermont and massachusetts, though steadily growing, through the energy and enterprise of their skillful artisans and mechanics, and the facilities afforded them by the last named road, have yet suffered and languished for want of the material so abundant in this undeveloped region between greenfield and the mountain barrier beyond. the water power of the deerfield river is immense, its fall along the line of the troy and greenfield road being nearly six hundred feet; and this magnificent force is now idle, except at shelburne falls, though the finest privileges are scattered along the whole course of the river. messrs. lamson & goodnow, who employ four hundred men at shelburne falls, in manufacturing cutlery, state that the deerfield and north rivers, at that place, afford a one-thousand-horse power. along the course of miller's river, between athol and deerfield are also many excellent privileges unimproved. at montague are turner's falls, on the connecticut, with a power sufficient to operate the mills of lowell, lawrence and manchester. all these splendid privileges only await the opening of the tunnel route. many of them would be at once improved were the road completed to the mouth of the tunnel. messrs. lamson and goodnow state that they shall double their present force of four hundred men, as soon as it is open to shelburne falls. some fifteen or twenty miles from the eastern end of the tunnel lie extensive forests of spruce and pine, through which a highway has already been surveyed, and which will be built to the tunnel, as soon as the road is completed to that point. the whole surrounding region abounds in lumber of almost every description, which would become very valuable when the road is built, to say nothing of the extensive formations of stone, soapstone and serpentine which are found there. though the deerfield meadows afford some of the finest farms in new england, the tillage land will not compare in extent with that along the western road; but in every other respect the resources and latent wealth of the tunnel route are infinitely superior to those of the western line. six years ago, and _twenty-three years after the western road was opened_, the population lying west of springfield within ten miles of the western road on a distance of forty-four miles, was , ; while that west of greenfield, within ten miles of the tunnel line on the same distance, without any railroad at all was , . according to the average rate of increase, the population along the tunnel line, would be more than doubled in twenty-three years. were the mountain barrier pierced, and communication opened with the west, and the magnificent water power of the deerfield made available, who doubts that this population would be increased fourfold in that space of time: or that more than one town would spring up between greenfield and the hoosac, in a few years, which would rival north adams in growth and prosperity; or that in far less time than it has taken lowell to acquire her present importance, a larger city than lowell would stand on the banks of the connecticut at turner's falls? with the requisite railroad facilities supplied, it is certain that the growth of a region so abounding in the most essential reliance of mechanical industry, as northwestern massachusetts, cannot be measured by the snail's pace which marks the progress of an agricultural district. the farmer's interests are indeed equally promoted with those of other industrial classes, by the opening of railroads, but these do not increase the number of farms or farmers within our borders, nor stimulate the growth of agricultural towns. it is mainly by her manufactures and commerce that massachusetts has become so prosperous and wealthy. it is because the commercial and industrial interests of the whole state require it, that another route to the west has become a necessity; and it is because such immense resources yet remain to be developed, and such a gigantic power to be employed, in northern massachusetts that the new route must pierce the hoosac mountain, if it is possible and practicable. that it is possible to tunnel the hoosac mountain cannot be doubted by any sane person who has inspected the half mile already excavated. all of the eminent engineers, whose reports upon the enterprise have been published, say it can be done; nor do any of its opponents pretend to question its practicability. but in order to estimate properly the magnitude of the work, its possible and probable cost, and the time within which it can be done, it is necessary to know what has been accomplished in this department of civil engineering. fortunately, this needed information is contained in mr. charles w. storrow's very able report on european tunnels. mr. storrow is a distinguished civil engineer, who made a journey to europe in the summer of , by request of the hoosac tunnel commissioners, and with the approval of the governor and council, for the purpose of examining the most important tunnels there constructed, and, especially, the one in progress under the alps. he describes twenty-two tunnels which he visited, besides that of mt. cenis. fourteen of these are in england, seven in france, and one in switzerland. two of them are upwards of three miles long, and many of them between one and two miles. some of the shafts were nearly as deep as the central shaft of the hoosac. some of these excavations were made without the aid of shafts, others wholly by means of shafts, without working from the ends at all. it might be supposed that in the construction of so many subterranean ways, in such different sections of the continent, almost every conceivable geological formation must have been traversed; and so it appears from mr. storrow's report. granite, quartz, oolite, limestone, shale, slate, sandstone, gravel, sand, clay and marl, were the material through which with pick and spade, drill and shovel, the patient workmen made their way. not unfrequently, more than half the varieties of rock and earth we have named were met with in the same tunnel. sometimes the work would be interrupted and temporarily abandoned in consequence of an inundation of water; sometimes enormous masses of gravel and sand would work through into a shaft or tunnel, with disastrous and, in two instances, with fatal consequences. in many instances, work was discontinued for years, for want of funds, and then afterward renewed, with eventual success. in fact, about the average amount of those ordinary and inevitable obstacles which stand in the way of all great enterprises, were encountered by the engineers and contractors, in the building of these tunnels; but time, money, and skill, never failed to remove every difficulty. but we propose to extract, and condense from mr. storrow's report, a few of the main facts about some of the most important of these works; as the report has, not been read, or even seen by one in a hundred. the "box tunnel" between chippenham and bath is more than a mile and three quarters in length. nearly one half its length passes through a kind of limestone rock, and the other through clay, the clay end being lined with masonry. five shafts were sunk, the deepest being about three hundred feet. "during the construction of this tunnel, great difficulties were encountered from the excessive quantity of water which inundated the works, sometimes even occasioning their partial suspension, and powerful means were required to overcome the obstacles. at one time the water fairly got the mastery over the machinery used for its removal, and it was only after an additional set of pumps worked by a fifty horse power engine, that the work could be resumed." this tunnel was built in five years, and its cost was about $ , , , or about $ a yard. the woodhead tunnel, on the manchester and lincolnshire railway, is upwards of three miles long. it was originally built for a single track, its dimensions being feet wide at the head of the rails, and feet in. high from the rails to the under side of the arch; which are almost exactly the dimensions of the present section of the hoosac tunnel. after a few years of use, the increase of business required another track and so a second tunnel of exactly the same size was built parallel with the first. it is a double tunnel with a thick dividing wall between, pierced with twenty-one arched openings. five of the original shafts have been kept open. the deepest of these is more than six hundred feet, and the least about three hundred. the rock through which the tunnel passes consists of millstone grit, a hard material, and shale, a kind of indurated clay. the kilsby tunnel is more than a mile and a quarter long, and is built in roman or metallic cement, under a bed of quicksand, from which it took nine months to pump the water, through shafts on either side of the sand bed. during a considerable portion of that time, the water pumped out was two thousand gallons a minute. the quicksand extended over feet of the length of the tunnel. the watford tunnel is a mile and one tenth long, excavated entirely from chalk and loose gravel, the treacherous nature of which rendered it a work of great difficulty, streams of gravel and sand sometimes pouring through the fissures of chalk, like water. the netherton tunnel is one mile and three quarters long. for its construction shafts were sunk, their total depth being , feet, the least depth of any one being feet, and the greatest, feet. there were faces to work at, and the progress at each face was - feet per month. the tunnel was completed in two years. from these brief descriptions of a few of the tunnels in england examined by mr. storrow, one can form a pretty correct opinion of the ordinary difficulties in tunneling which have been met and overcome by the english engineers. mr. storrow says that tunnels are not considered there such formidable works as they have generally been esteemed in our northern states. they are so common that they have long ceased to attract the attention of travelers, more than eighty miles in aggregate length being already in use. mr. storrow estimates the average progress made in the construction of the english tunnels at about thirty feet per month on one face, and that the cost per yard varies from $ to $ , for ordinary tunnels; but where peculiar difficulties were met, the cost has reached to from $ to $ per yard. the hauenstein tunnel in switzerland, one mile and an eighth in length, was from four to five years in being constructed. two shafts were sunk, one feet, and the other feet deep. portions of the shafts and tunnel were lined with masonry on account of the water and sand, and varying firmness of the strata passed through, all of which caused many difficulties and delays. the progress made between the intervals of obstruction, varied from fifty-six to one hundred and nine feet per month on a face. the cost was about $ per running yard. the nerthe tunnel in france, is nearly three miles in length. for nine hundred and fifty yards of its length it is in rock cutting, where arching was unnecessary. the remainder is lined with masonry. twenty-four shafts were sunk, varying in depth from sixty-five to two hundred and sixty-two feet. the work was completed in three years, and cost $ per running yard. the tunnel of rilly, on the line from paris to strasbourg, is a little more than two miles long. eleven shafts were commenced, two of which were abandoned on account of the abundance of water, the others were completed. in some of the shafts the water was so troublesome that it was necessary to use for curbs cast iron cylinders, five feet in diameter, and about three feet long, bolted together. the time consumed in the construction of this tunnel was three years and four months. it passes through a chalk formation, which was, in some places, so seamy, that great precaution was necessary to prevent the falling in of large masses. the cost was $ per running yard. mr. storrow visited and examined several other french tunnels, and his reports upon them are full of interest; but the abstracts given are sufficient to show the various obstacles and difficulties encountered by the english and french engineers in the prosecution of their work, as well as the cost, and the success which rewarded their skill and perseverance. we now come to the great tunnel under the alps, the most remarkable and gigantic enterprise ever attempted in civil engineering. our facts in regard to it are derived from mr. storrow's report, (which it will be remembered was made in november, ,) and from a very able account in the edinburgh review of july, . the object of this work is to connect france and italy, by a continuous line of railroad, by piercing the great alpine barrier which separates savoy from piedmont, and thus connecting the valleys of rochmolles and the arc. when the scheme was first suggested it seemed like a dream of enthusiasts. the distance would be more than seven miles. no shaft could be sunk, as it was estimated that it would take forty years to reach by that means the line of the axis of the tunnel. the gallery must then be constructed by horizontal cutting from the two ends. how were the workmen to breathe? what chasms, unfathomable abysses and resistless torrents might not be encountered? was it certain that the two sections commenced from the opposite ends would not miss and pass each other in the middle of the mountain? but as the subject was more thoroughly discussed, these doubts and fears seem gradually to have faded away, and a conviction took possession of the public mind that such a tunnel was practicable. this conviction at last assumed form and development through the genius of messrs. sommeiller, grattoni and grandis, three young italian engineers, who have won for themselves a nobler fame than that of either of the great generals who led their armies over the alps. it was their good fortune to have secured the confidence of one of the most enlightened statesmen of modern times, count cavour, the energetic minister of victor emanuel, who, throughout all the doubts, perplexities and embarrassments attending the first stage of a new and bold enterprise, exposed to criticisms, sometimes ignorant, sometimes malevolent, on the part of politicians and professional men, gave these engineers his "constant, earnest and sanguine support and encouragement." it appears that an english engineer had patented a machine for drilling by steam, by means of which the drills were darted forward against the opposing rock with great velocity and force. but steam could not be used in the tunnel, where the great desideratum is a supply of fresh air. in the meantime messrs. sommeiller, grattoni and grandis had turned their attention to the question of compressed air as a motive power, and after a long series of experiments; gave to the world as the result of their joint ingenuity, a machine which acts simply by the force of air reduced to one-sixth of its ordinary volume, by means of the pressure of water. the quick perception and practical genius of our three engineers soon enabled them to combine their machine with the perforating apparatus above named, so that the compressed air took the place of steam, and performed its work perfectly. this combination is the machine which has been in successful operation under the alps since june, , and which, greatly improved and perfected by yankee ingenuity, is about to be applied to the hoosac mountain. before proceeding to give some account of the alps tunnel, it should be stated that it is a national work, and not a commercial speculation. it was originally undertaken by sardinia, within whose territorial limits it was then wholly included. the cession of savoy to france brought nearly half the tunnel into french territory, and by the convention establishing the new boundary between france and italy it was stipulated that this great national work should be continued, should remain exclusively under the control of the italian engineers, and that france should pay into the sardinian treasury its proportion of the cost, according to an estimate then made and considered final, and fixed at francs for each running metre, equivalent to $ for each running yard of its length in french territory. the work has remained, therefore, as it was, under the exclusive direction of m. grattoni and m. sommeiller, the engineers; and a french commission visit the work from time to time, by order of the french government, to view its condition, ascertain its progress, and vouch for the amount to be paid to sardinia. it is hardly necessary to give a detailed description of the mode by which the compressed air is made to act on the perforating machines at mount cenis. the problem was how to get a constant equable supply of air compressed to one-sixth of its ordinary bulk. to effect this a reservoir was constructed at bardonneche, elevated to a height of eighty-two feet above the works, which furnishes a moving force of two hundred and eight horse power, that being all which is required to operate the drills and ventilate the tunnel. the reservoir is supplied by a never failing mountain stream. from the compressing works, the air is conveyed in a pipe into the tunnel to the drilling machines; another pipe conveying water to wash out the drill holes. at the fourneaux end of the tunnel, the reservoir is supplied with water by means of pumps. the compressed air and water being ready for their work, an iron frame containing the perforating needles moves along the rails and confronts the rock which is to be attacked in the gallery or heading. the frame is armed with nine or ten perforating machines arranged so that the greatest number of holes can be bored in the center of the opposing mass of rock. to each of these are attached flexible tubes, one containing the compressed air which drives the drills, and the other water, which is injected into the holes as they are bored. the machine consists of two parts; the one a cylinder for propelling the drill, by means of a piston, and the other a rotary apparatus for working the valve of the striking cylinder, and turning the drill on its axis at each successive stroke. to bore eight holes of the required depth, the piston rod gives , blows. the action of each machine is independent of the other, so that if one of them is broken, or gets out of order, that of the rest is not delayed. the drills act at different angles so as to pierce the rock in all directions, and when the requisite number of holes have been drilled, the iron frame is pushed back, and the central holes are charged and exploded. the smaller surrounding holes are then charged and fired. at each blast, a strong jet of compressed air is thrown into this advanced gallery to scatter the smoke and supply air for respiration. wagons are next pushed forward and filled with the fragments of broken rock, which are conveyed to the mouth of the tunnel and dumped down the side of the mountain. after each blast a fresh relay of workmen come in, and the same operation is repeated night and day. one of the objections urged against the use of compressed air as a motive of force was, that if it were conveyed a long distance it would lose so much of its elasticity or expansive power, that it would be unavailable for any practical purpose. but this conjecture was confuted by facts. it was found that the loss of pressure at the ends of the conduit pipes where the air is applied, as compared with the pressure in the reservoir is only one sixteenth of the whole. m. sommeiller calculates that in the center of the tunnel, a distance of three miles and three quarters from the reservoir, he will be able to apply the necessary pressure of six atmospheres. that m. sommeiller is correct in this opinion appears to be conclusively proved by the latest accounts from mt. cenis, which state that the work is steadily progressing, that one half of the entire length would be excavated by the first of january , and that at a distance of nearly two miles from the reservoir, the drills were operating with as much force as ever, and that there was no appreciable loss of motive power. in the middle of the tunnel line beneath the rails, there is made at the same time with the excavation, a covered way or drain, in which are laid the pipes for gas, water, and compressed air. by this drain the waste water runs off, and it is also intended to serve as a means of escape for the workmen, in case of a fall of rock, or other accident which might block up the tunnel. of course the tunnel must be continually supplied with fresh air along its whole length, as well as at the heading. this is easily done from the compressed air tube in the covered drain. the whole length of the mt. cenis tunnel is through rock varying in hardness, and veined throughout with quartz. in many parts it is liable to flake off, and in some places considerable masses have broken away during the construction. the full section of the tunnel is twenty-six feet and three inches wide, and twenty feet and eight inches high. the heading is carried forward about eleven and a half feet wide and nearly ten feet high. at the time of mr. storrow's visit the drilling machines were used only in the heading. the whole of the enlargement was done by hand labor in the ordinary way. the drills when brought up to the work drill eighty holes before any blasting is done. about ninety workmen are employed at each end. it required from five to seven hours to drill the eighty holes. mr. storrow visited a workshop where some machines were ready, and a large block of stone was placed in front of them for trial. the air was let on and a drill put in motion. in - minutes it drilled - inches. the engineer stated that they would make better progress than that at the rock in the tunnel. the average progress made by hand was about sixty-six feet a month. that rate was about doubled by means of the machines; but since mr. storrow's visit these machines have been greatly improved, and the rate of progress latterly has been about two hundred feet a month. the opening of the mt. cenis tunnel was commenced in october, . up to july, , about feet had been excavated, the average progress being about sixty-six feet a month. the machines were then introduced, and at the present time, upwards of three miles have been excavated, and at the rate of progress now being made the tunnel will be completed in four years. mr. storrow's estimate of its cost is $ per running yard. we have now placed before our readers such facts in relation to european tunnels, and more particularly in relation to that under the alps, as will enable them to judge for themselves of the feasibility of completing the hoosac tunnel, and of the weight of the objections which are urged against it by the opponents of the enterprise, as well as the nature of the obstacles which have been encountered, and the means of surmounting them. we shall next present a brief history of the work, the progress made, the delays which have occurred, and the causes; and the sources, nature, and motives of the opposition which has been made to it. in the course of this history we shall have occasion to expose the gross misrepresentations and deliberate falsehoods which have, from time to time, been put in print and scattered broadcast throughout the state, for the purpose of sustaining and extending a great railroad monopoly, already too powerful, against the vital interests and actual necessities of the commonwealth. the first section of the tunnel line obtained its charter in , under an act incorporating the fitchburg railroad company, in spite of the strenuous opposition from boston, springfield, pittsfield, and the whole power of the western road, which a few years before, had only obtained its charter by the aid of some twenty-five members of the house, from northern massachusetts, who held the balance of power. of these twenty-five gentlemen, to whom the state was thus early indebted, one was hon. alvah crocker, of fitchburg, whose name in connection with the fitchburg, the vermont and massachusetts, the troy and greenfield roads, and with the hoosac tunnel, has since become "familiar as household words." the appeal of the late judge kinnicut, one of the pioneers of the western line, contains this passage: "assume if you please, that your route is better than the southern or western one; if you are willing to identify the commonwealth with such an enterprise, you establish a precedent, and the commonwealth, to be just, to be consistent with herself, must aid you in like manner. nay, every other section. she will never be partial, as you suppose, but fair to all. she will certainly go as far as she safely can, to develop and increase her growth." such appeals could not but prevail with fair minded men, and these twenty-five members, with a spirit of liberality and almost of self sacrifice, which should put to shame the narrow minded and selfish policy of the western railroad company in regard to the tunnel line, gave their voices and votes in favor of an enterprise, the commencement of which would otherwise have been deferred for years. the result was that by the first of january, , the receipts of money by the western railroad company, from the stock and scrip of the state amounted to $ , , . . as stated above, the fitchburg railroad company was authorized to build a road from boston to fitchburg, a distance of fifty miles, in spite of the strenuous opposition of the managers and attorneys of the western line. the intelligent legislator of , who has passed over the fitchburg railroad, and observed the numerous trains of passenger and freight cars which daily follow each other over its double line of track, can but smile at the language of mr mills, a senator from hampden, a little more than twenty years ago "sir," said this zealous legislator, who, in his style and logic forcibly remind us of mr. bird, of walpole, "a six horse stage coach and a few baggage wagons will draw all the freight from fitchburg to boston." it is hardly necessary to give details of the history of the vermont and massachusetts road, and the struggles of its projectors against hostile legislation, and the intensified opposition of the western line. suffice it to say that this second section of the tunnel line, extending from fitchburg to greenfield, was commenced and finished, in spite of all opposition, without a dollar of that aid which mr. kinnicut said the state would have to furnish in order to be just and consistent. its stock, which could be bought for $ a share, ten years ago, now commands upwards of $ . its gross receipts, last year, were $ , . , and its net income, $ , . . its debt has been reduced from upwards of a million to one half that sum, and this year it has paid its first dividend. the troy and greenfield road was chartered in , the same old elements of opposition being combined against, and fighting it at every step. the managers of the western road clamorously declared that if this competing line were chartered, it would greatly diminish the security of the commonwealth, for its investment in their road, and that if the state should be compelled to sell its stock after the granting of such charter, she would lose a hundred and seventy thousand dollars; while, at the same time, they affected to deride the vermont and massachusetts as a "pauper road," and the region it traversed as a "god-forsaken country!" in , the western end of the tunnel line, extending from the western base of the hoosac mountain to troy, had been completed through the enterprise of the citizens of that thriving city and those of north adams. the vermont and massachusetts was finished, and only thirty-seven miles of rail were needed to complete the direct connection of boston with the great west. then was the time and opportunity for the state to have continued the same liberal policy which it had adopted toward the western road, and to have extended her helping hand to the struggling corporation, which had undertaken the noble enterprise of piercing the barrier which was interposed between them and their "promised land." but their appeals for aid were met with sneers and derision; the work was bitterly opposed at every stage of its progress; the arts of demagogues, the cunning of lawyers, the fears of the timid, the credulity of the ignorant, and every conceivable influence which the well-filled treasury of the western road could purchase were enlisted and combined against it. but, at last, perseverance and a good cause prevailed, and in , the legislature authorized a loan of the state credit to the amount of two millions of dollars, to the troy and greenfield railroad company, "for the purpose of enabling said company to construct a tunnel and railroad under and through the hoosac mountain, in some place between the 'great bend,' in deerfield river, and the town of florida, at the base of the hoosac mountain on the east, and the base of the western side of the mountain, near the east end of the village of north adams, on the west." but this loan was modified and restricted by such conditions, artfully introduced by the foes of the enterprise, that the work still languished, and its friends almost despaired even of ultimate success. the enabling act of , would have greatly relieved them, but it was vetoed by gov. gardner. at the beginning of , only $ , of the two millions had been advanced. in the legislature of that year, the original act was modified so that the balance of the loan might be divided between the road from greenfield and the tunnel, for the construction of both parts of the work simultaneously. provision was at the same time made for the appointment, annually, by the governor, of a state engineer, to examine the work, make monthly estimates, and impose such requirements upon the company and contractors as he and the governor and council might deem expedient. in the summer of , colonel ezra lincoln of boston, was appointed state engineer, and resigning in the following autumn, on account of illness, was succeeded by c. l. stevenson, esq. in the meantime the company had contracted with messrs. haupt and cartwright to construct the road and tunnel. the first named gentleman was one of the most eminent and experienced engineers in the country. under the administration of the state engineers, messrs lincoln and stevenson, the existing location was approved, and certain prices were established, upon the basis of which contracts were made for labor and material, and rapid progress was made with the work. upon the accession of governor andrew in , mr. stevenson was summarily removed, and mr. william s. whitwell appointed in his place. this gentleman at once proceeded to change the entire basis of work as established by his predecessors, reduced the prices under which extensive contracts had already been made, and cut down the estimates, so as to compel an entire suspension of the work. more than a thousand laborers and mechanics were discharged. mr. haupt states that at the time of this suspension, "the graduation of the whole line could have been completed in a few weeks. the iron and nearly all the ties and bridge material had been delivered; but little remained to be done except finishing the bridge and laying the track." after a warm and protracted discussion of the subject in the legislature of , an act was passed, providing that the state should take possession of the road, tunnel, and all the property of the troy and greenfield company. a commission was also authorized to examine the work, ascertain the feasibility of completing it, and report to the next legislature. the commissioners appointed under this act, by governor andrew, were messrs. j. w. brooks and alexander holmes, of massachusetts, and mr. s. m. felton, of pennsylvania, two of them being eminent civil engineers, and all three gentlemen of large experience in railroad affairs. they entered upon the duties of their commission at once, and having dispatched mr. storrow to europe to examine the tunnels there, proceeded to take possession of the road and property of the company, which was surrendered to them in september of the same year. the elaborate and exhaustive report of the commissioners was submitted to the legislature in the latter part of february, . the closing paragraph expresses their "opinion that the work should be undertaken by the commonwealth, and completed as early as it can be, with due regard to economy." the result of another discussion in the legislature was the adoption of the recommendation of the commissioners, and the responsibility of completing the tunnel and road was assumed by the state, in april of , operations having been suspended nearly three years. since that time, the work has been conducted by the commissioners, under the immediate superintendence of mr. thomas doane, chief engineer, in such manner and with such progress as to give very general satisfaction to the friends of the enterprise, and promise its completion within a reasonable time. a very considerable portion of the labor and expenditures, since the operations were resumed, have been applied to preparing buildings and machinery, to the construction of a dam across the deerfield river, in order to secure power to operate the tunneling apparatus, and to an enlargement and an alteration of the grade of the eastern end of the tunnel, which had been excavated by haupt and cartwright. but before proceeding to consider the present condition and prospects of the tunnel, it is necessary to revert to the legislation of and , in order to note the tactics of its enemies, who had by no means been idle, nor had in any degree relaxed their opposition. in fact, it was through this opposition that the act of was effected, the bill being a substitute for that reported by the committee, and generally regarded as a compromise between the friends and foes of the enterprise, though the latter believed they had, at last achieved a triumph, and exultingly whispered that the great hoosac tunnel scheme had received its death blow. they certainly did play their game with boldness and skill. while the contractors, messrs. haupt & co., had actually applied all their private means, to the extent of more than $ , , to carry on the work, it was asserted that they were swindling the state and pocketing its funds to the tune of $ , . they proclaimed that they were in favor of the tunnel, and only desired to take the work from the hands of swindling contractors and the control of a bankrupt and irresponsible corporation, in order that it might be assumed and prosecuted by the commonwealth; but they were secretly confident, and not without reason, that a board of commissioners would be appointed who would report against the prosecution of the work by the state. of the three gentlemen appointed, not one had expressed an opinion in favor of the enterprise, and mr. brooks, the president, was known to be opposed to it. both of the two resident members were from localities where the prevailing sentiment was against the tunnel. but this adroitness of the opposition was baffled, and its confident hope disappointed by the integrity and fairness of mr. brooks and his associates. the latter had no prejudices to conquer, and mr. brooks had not applied himself many weeks to the duties of his commission, before he was convinced of the feasibility of the work, and satisfied that the state ought to assume and complete it. when their report was made to the legislature in , the old opposition manifested itself with more intensity than ever, and the same honest gentlemen, who, the year before, were so friendly to the enterprise, and only wanted to transfer it from the hands of rapacious contractors and a bankrupt corporation, to the fostering care of the commonwealth, threw off their masks, resorted to their old tricks and arts, and renewed their old clamor, against the "tunnel swindle;" yet, vainly, as the result proved. the name of mr. f. w. bird, of walpole, has been once or twice mentioned in this article, and not improperly, since he has gained that equivocal notoriety in connection with the hoosac tunnel, which attaches to the enemies of all great and noble undertakings. this gentleman has informed the public, that in and , when he was in the legislature, he "voted for everything that the friends of the tunnel asked for." this action cannot have greatly embarrassed mr. bird during his subsequent career, since the only thing asked for by the friends of the tunnel, during those two years, was the charter, granted in . mr. bird further informs the public, that "in , we were overruled by the committee, but we defeated them before the legislature. in , we were defeated, and the legislature sanctioned the resumption of the work." mr. bird also boasts that, while a member of the executive council, he "did resist the assumption by the chairman of the commission, of irresponsible control over the work, and did something to prevent the building of the road from greenfield to the mountain." in , hon. w. d. swan represented the opposition to the tunnel in the senate. mr. bird, in a communication to the boston journal of nov. , , says:-- "the tunnel fight was organized and directed by three members of the third house. the tunnel matter came before the senate late in the session, when many important questions demanded the attention of the senate and rendered it very difficult for them to make personal investigations. as to mr. swan, he very frankly declared that the whole subject was so new to him that he must rely upon us for his materials. his published speeches upon the tunnel, upon which his fame as a practical legislator is based by his friends, were written substantially by one of us beforehand, and afterward revised by all of us for the press. we furnished every fact, made every calculation, prepared every table and arranged _every point and every argument logically and rhetorically_." one of the arguments which mr. bird confesses he and his associates "arranged," is expressed in the following extract from mr. swan's speech:-- "i am aware, sir, that it may be said: 'you are going to stop a great enterprise.' no i am not. i have no such intention. i am in favor of the hoosac tunnel. if massachusetts has granted her aid for the accomplishment of any great purpose, i am for going through with it. i am for going through with the tunnel; but i am for going through with it understandingly; and if massachusetts is to do the work, let us know that we are to obtain something like an equivalent for our expenditure. we say, then, to the corporation, we will send intelligent commissioners to examine the road and tunnel, and if the report to us, or our successors, next year, is favorable to this great enterprise, we will go on with it; we will bore a a hole through the mountain, we will arch it, lay the track, and give you ten years in which to redeem the property." but it is not necessary to quote further from mr. bird himself; he has been well known for years as an agent of the western railroad company, and the leader of the combined elements of opposition to the tunnel. he is a man of ability, bold, and adroit in his management, but entirely unscrupulous in the choice of means to effect his objects. as a lobby member, as newspaper correspondent, as pamphleteer, as councilor, and in the numerous other characters which his protean genius has enabled him to assume, he has, by fair means and foul, diligently adhered to his boastful promise that he "should not desist from opposition till the work is stopped;" and he has lately reiterated his purpose of keeping that pledge, "with the help of god." those who know mr. bird well, entertain no doubt that he will continue to do his best to stop the work, whether with or without the divine assistance, and that he will literally fulfill his promise, since the work will, undoubtedly, be "stopped" when it is finished. one other gentleman has been associated with mr. bird, as a leader of the opposition to the tunnel enterprise, who, perhaps, deserves a passing notice in this article, mr. d. l. harris, president of the connecticut river railroad. he has less ability than mr. bird, but much more practical knowledge of railroad engineering and management. it has apparently been a part of the duty assigned him, to furnish mr. bird with the texts for his pamphlets and newspaper articles, and to supply such information, from time to time, as that gentleman's inexperience and ignorance required. he has also emulated the example of his associate by contributing to the anti-tunnel literature of the newspapers. while a member of the house, a few years since, he had the bad taste, in the course of discussion, to quote from one of his own anonymous articles. upon being accused of being the author of his quotation, he roundly denied the charge, but was convicted by the production of his own manuscript. his seat was vacant during the remainder of that session. whether this desertion of his post was occasioned by a conviction in the minds of anti-tunnel men and the western railroad managers that the exposure had impaired the influence of their agent, or whether he was impelled to retire by the stings of that remorse which a certain class of men experience only when they have been detected in a falsehood, the writer of this paper is unable to determine. the boston advertiser of october , , contains an article over mr. bird's signature, which was soon after published in the form of a pamphlet, and profusely distributed throughout the state, having for a title, "the hoosac tunnel: its condition and prospects." it appears, that a few weeks previous, mr. bird and mr. harris visited the tunnel locality, and this pamphlet purports to be the result of mr. bird's "observations." it has been extensively read, and has, doubtless, inspired the minds of many timid and ignorant persons, with honest doubts of the practicability or expediency of ever completing the tunnel. it is considered "smart" by those who mistake denunciation and abuse for wit, and baseless assumption for truth. to those who are familiar with the history of the tunnel, and who understand its present condition, it is more remarkable for misrepresentation and disingenuousness, than even any previous effort of its author. he introduces his subject by stating that the commissioners, "since they commenced operations, have had unlimited and irresponsible power, and that, for all failures and blunders, they, and they alone, are responsible;" yet, within a month from the penning of this assertion, mr. bird boasted that _he_ did something, while a member of the council, to prevent the building of the road from greenfield to the mountain. the obstacles encountered at the west end of the tunnel, which had been foreseen and understood from the beginning, by the friends of the enterprise, appear to have first engaged the observation of our inspector, and are represented as a startling and recent discovery. the well known effect of water upon the soft material in this locality is described as "rock demoralized" into "porridge," and this "porridge" is represented as a difficulty of such serious nature that "the managers are at their wits' ends." mr. james laurie, an eminent civil engineer, employed by the commissioners to make a survey, in his able report in january of , says "the portions of the hoosac tunnel embraced between the western entrance and the present shaft, a distance of feet, will, from all indications, be the most troublesome and expensive. the material consists of gravel, clay, sand, detached beds of quartzose sandstone, some of which is partly decomposed, and limestone. the whole formation is full of springs. _however bad the material may prove_, this part, under proper management, can be completed long before the rest of the tunnel." mr. bird says, "common men, and some uncommon men, too, look upon these difficulties as insuperable." those who can, for a moment, weigh the opinion of the accomplished and experienced engineer, mr. laurie, with that of mr. f. w. bird, of walpole, may relieve their doubts by referring to mr. storrow's report on the european tunnels, in a very large proportion of which the most formidable kind of "porridge" was encountered and subdued. mr. bird observed the western shaft. the work at the western face of this shaft was suspended on account of imminent danger of "porridge" and our observer's most important criticism here, is that they were, at the time of his visit, advancing on the eastern face of the shaft, at the rate of only "thirteen feet weekly," that is fifty-two _feet per month_. mr. storrow says the average progress in the european tunnels was about thirty _feet per month_. the central shaft was visited, and mr. bird does not appear to have observed anything which demanded an expression of his disapproval. the work was progressing at the rate of twenty-two feet a month, and the pumps gave a gallon and a half of water per minute. in constructing the kilsey tunnel, in england, mr. storrow says that during a considerable portion of nine months, the water pumped out was two thousand gallons a minute. mr. bird's report of progress at the east end was certainly very encouraging the heading having been advanced successfully during the two months preceding his visit, at the rate of sixty-five feet per month, and the work was being pushed with vigor and activity. the dam across the deerfield next claimed the observation of the inspector, who appears to have regarded it with much surprise, both on account of its cost and because it was thrown across a fitful mountain torrent, so feeble at the time of mr. bird's visit, that it was only allowed to run by night, for the reason, as he "guessed," that "if it was allowed to run by day, under the hot sun, it would all evaporate before it reached shelburne falls!" this _guess_ is associated in the same paragraph with an assertion that "there was not then in the river, and had not been for some weeks, and has not been since, (unless they have had heavy rains,) water enough to give under a thirty feet head, twenty, or even a ten-horse power, for twenty-four hours a day." it is as well established a fact that the deerfield river was never known to be so low as at one time during last year, as it is that wells all over the state were dry last autumn, which were never dry before. yet, at the time of mr. bird's visit, when the river was lowest, mr. doane, the chief engineer, states that the water was running at the rate of "thirty-four cubic feet per second. on a head of thirty feet this gives, theoretically, one hundred and sixteen, and, practically, eighty-seven horse power." the intelligent reader will not be at much loss to decide whether he will rely upon the guesses, observations and loose assertions of mr. bird, or the record and word of the careful and skillful engineer. mr. bird says, "it is discreditable that the precise quantity of water has not, so far as we know, been ascertained by actual measurement." such measurement had been made, and mr. bird _might_ have known it if he had taken pains to inquire of mr. doane or mr. hill. the testimony of messrs. lamson & goodnow, of shelburne falls, as to the power and reliability of the deerfield river, is that "this is the first season we have been at all troubled on account of the scarcity of water, but not as mr. bird stated it. we have not been compelled to stop our mills _except one half day_, and we employ four hundred men on cutlery." the same gentlemen (messrs. lamson & goodnow) state that the deerfield and north rivers furnish water enough, at shelburne falls, for one thousand horse power. the north river is a small stream, and deducting its contribution together with that of the brooks which find their way into the deerfield between shelburne falls and the mountain, at the high estimate of two hundred horse power, and there remains to the deerfield alone a force of eight hundred horse power, which is the estimate made by the commissioners. the measurements made by mr. doane and his assistants confirm their accuracy. yet mr. bird who boasts of "an intimate acquaintance of over thirty years with water power," asserts that for such a privilege, "ten thousand dollars would be an extravagant price!" would he sell even the puddle which works his paper mill at walpole, and which, we presume, has afforded all his knowledge of water power, for half that amount? the writer of this article has not enjoyed "an intimate acquaintance of over thirty years with water power," but he has resided exactly the same length of time as gov. gardner said he had been a temperance man, in the manufacturing town of fitchburg, and during that time has learned something about its _thirty-four_ water privileges and _five hundred and eighty-two feet head_ of water which they command, on the little nashua and its tributaries. his knowledge of this water power enables him to exhibit the gross absurdity of mr. bird's efforts to dry up the deerfield. one of these tributaries, which is less than eight miles long, affords a privilege with a head of twenty-one feet, of from seventy-five to one hundred horse power. the reader can form his own conclusions, by comparing this brook with that "fitful mountain torrent," the deerfield river, which has its sources in the town of stratton, vt., flows southward to the foot of the hoosac mountain, then turning eastward, finds its way into the connecticut, near greenfield, traversing in its course, a distance of more than sixty miles. the length of the "fitful torrent" above the hoosac dam, is about forty miles, and in that part of its course it is swelled by the contributions of numerous tributaries, several of which are respectively from twelve to eighteen miles long. a shrewd yankee, who is not a civil engineer, and has not even had the experience of running a small paper mill, might "guess" that such a stream would furnish, with a head of thirty feet, as much as an eight hundred horse power. but it is not eight hundred horse power, nor four hundred that is required to operate the drilling machinery and ventilate the tunnel; for two hundred and eight horse power is all that has ever been used or needed at mt. cenis. this leaves a pretty wide margin for drouths, _evaporation_, and other contingencies. in his observations upon the power required, mr. bird becomes severe and sarcastic. he assails the opinion of the commissioners that "the loss of power by carrying the compressed air through five miles of pipe will be quite insignificant;" and after asserting that there are no _data_ by which to test the correctness of this opinion, and claiming "some experience in such matters," prefers that such an "_experiment_" should be tried with somebody's money besides his own. it is gratifying to learn from mr. bird, himself, that he he has had experience in the matter of compressed air as a motive power, and that a "cussed furriner," as he elegantly phrases it is not to be allowed to bear off the palm of this great discovery uncontested. doubtless m. sommeiller will yield to the superior science and sagacity of mr. bird; but our countryman should lose no time in informing his fellow citizens of his investigations, experiments and success in arriving at the conclusion that compressed air cannot "be carried through five miles of pipe without a very serious loss of power through friction, leakage, &c." but, unfortunately for this view of the case, there are data establishing the fact that compressed air has been conveyed through more than two miles of pipe at mt. cenis, and then operated the drills without any appreciable loss of power. if there is no loss in two miles, how can there be in five? it is no longer an experiment, but an established scientific fact. the size of the present excavation next engages the attention of our observer, and he calls the commissioners to account because they have not followed their own recommendation to excavate the tunnel to its full dimensions as the work proceeds. since their recommendation was made in the winter of , the commissioners have had much experience, and the price of labor has doubled. only a small number of men can work on a heading, but when a heading has been advanced a large number of workmen can follow rapidly in enlarging the excavation, and will soon overtake those engaged on the heading. at mt. cenis, the pneumatic drills are only used on the heading, and the enlargement is done by numerous laborers with hand drills. it is apparent that the commissioners have been actuated solely by motives of economy in prosecuting the heading alone, at the present high rates of labor. the work of enlargement is comparatively easy and rapid, and might well await a decline in the cost of labor, though it must be admitted that the importance of completing this noble work, ought to outweigh the consideration of _any possible_ cost. on the subject of pneumatic drills, mr. bird is emphatic. he says, "no intelligent man puts the slightest confidence in the successful working of any borer, or drill, in the rock of the hoosac mountain, unless operated by hand. in a strictly homogeneous rock, machine drills might work, but in a rock like the hoosac, where the drills, working generally in a comparatively soft material, are liable at any moment to strike veins of quartz, and where a part of the hole will be in the slate and the rest in quartz, no machine drill has yet been found to stand." this reckless and false assertion is made in utter defiance of mr. storrow's report and all other authorities upon the alps tunnel, which has now been excavated nearly four miles with machine drills on the heading. mr. storrow says that masonry is used because the rock "is not homogeneous in character. i stood at the front of the machines, watching them for three quarters of an hour. one drill was driving directly into hard quartz, advancing very slowly, and making the sparks fly at every stroke. others working in softer spots, were cutting rapidly." mr. bird has much to learn about pneumatic drills, and, without going beyond the borders of massachusetts, he can see a drill operate by compressed air, so indifferent as to the character of the rock it works upon, that it will penetrate the hardest granite and the composite rock of the hoosac with the same facility, and at a rate which would astonish even m. sommeiller. the figures upon which bird bases a "calculation" as to the time of completing the tunnel, are as far from being correct as his general statements are from the truth. one example is enough to illustrate, and by this the reader may fairly judge what the "calculation" is worth. he says the total length of the tunnel is , feet, when the _fact_ is that it is , feet. this is no mistake of the printer, for the figures repeatedly occur in the pamphlet, and always the same; and it is with this gross blunder that the "calculation" sets out. the truth is that any careful reader of this article, is a better judge of the whole subject than mr. bird, because he will have reliable dates, facts and figures, by the aid of which he can make a calculation for himself, or' form an opinion as to the time within which the work can be done, which will be quite as likely to be correct as any, "i undertake to say," of the oracular bird. on the st of december, , the penetration at the east end was feet; at the east heading of western shaft, feet; west heading of same shaft, feet; at west end heading, --in the whole, feet. the central shaft had been sunk two hundred and twenty feet. the average progress on this shaft during the months of august, september, october and november was - feet per month. assuming this for the average in december, january and february the shaft was feet deep, on the st of march, the whole depth to grade being feet. the average progress on the east face of western shaft was sixty-three feet per month. allowing that average for december, january and february, and the penetration on this face is now more than feet. the average on east end was forty-four feet. add this average for the last three months, and the penetration at this end is now feet, and the total penetration feet, with feet of shaft sunk. mr. laurie states in his report that in the ten tunnels which he names, in this country and europe, the average progress made on each face from a shaft was thirty-eight feet, and on the end faces fifty-four feet per month. let the intelligent man who forms opinions and conclusions for himself, compare the statistics which have been given in the course of this writing in relation to tunneling in europe and in this country, and then, taking into consideration the inadequate means which have, until recently, been applied to the hoosac enterprise, and surveying the progress which has been made whenever the work was prosecuted with vigor, let him judge how soon, and at what cost, the tunnel may be completed, even without the aid of machine drills. the concluding pages of the pamphlet contain a general charge against the commissioners, or rather mr. brooks, the chairman, of mismanagement. the only "_illustrations_" of this charge are, first, that mr. brooks declined to sell the , tons of railroad iron which had been purchased, and distributed along the graded track from greenfield to the mountain, and "other saleable property;" second, that he has "disregarding the advice of others, whose judgment was entitled to weight, put his own constructions upon the acts of the legislature relating to the powers and duties of the commissioners, in opposition to the construction and in defiance of the orders of the executive council;" third, he has seriously contemplated "the amazing folly of building the railroad from greenfield to the mountain!" it is gratifying to know from more reliable authority than the intimation of mr. bird, that mr. brooks did justify the opinion which is generally entertained, of his good sense and judgment, by contemplating that "amazing folly," and the only evidence of serious mismanagement on his part, which mr. bird can produce, is that he did not, at once execute his purpose, lay the rails and put the road in operation from greenfield to the mountain. the additional facilities which the completion of this road would have afforded for expediting the work, and reducing its cost, are too obvious to be enumerated. the extent and value of the resources and material of the region through which the road passes, and the importance of their speedy development, have already been shown. the distance from greenfield to the mountain is about thirty miles, by a very uneven and hilly road; and yet, in , the amount of freight transported over it, was , tons, and the freight and livery receipts were nearly $ , . with a good railroad in operation, in the place of a rugged highway, and the summer travel which it would induce, there can be no doubt whatever, that the local business alone would afford receipts very far beyond the estimates, upon which it is presumed the offer of the fitchburg and vermont and massachusetts companies to take a lease of the road was based, that is, $ , a year more than running expenses. whether mr. brooks is responsible for the delay in putting the road under contract, and for the waste and damage which have resulted from a neglect of three years, or whether mr. bird _did_ succeed, while a member of the council, in procuring an absolute injunction, the public cannot now well determine, for, as the reader has already observed, bird declares that mr. brooks had absolute power, that the whole responsibility rests with him, and yet boasts that he "did something" towards preventing the completion of the road. * * * * * since the foregoing pages were written, mr bird has published and distributed another pamphlet, the remarkable audacity of which challenges our attention. if one half of the assertions it contains were true, if one half of its calculations and estimates could be demonstrated, the hoosac tunnel ought to be abandoned at once, as the greatest folly of the nineteenth century, and its ruins sacredly preserved as a monument to coming generations of a monstrous popular delusion: and if the epithets--swindlers, tricksters, liars, plunderers, thieves, ingrates, rascals, traitors and fools--which mr. f. w. bird, of walpole, so freely and indiscriminately applies to everybody who has advocated or favored the building of this tunnel, were deserved; then a very large proportion of several legislatures, a majority of several executive councils, and many distinguished citizens and state officers, including the late governor and attorney general, ought to be lodged for the remainder of their days either in the state prison, or the asylums for idiots. this last publication of bird's is mainly a repetition, "with embellishments," of his previous pamphlet, with the addition of a preface purporting to be the history of tunnel legislation to the beginning of the present year, a string of calculations and conjectures as to the capacity of the western railroad to transport ( provided it were properly managed, and the double track completed) all the western freight and travel for all future time, and several pages of coarse denunciation of mr. brooks, chairman of the tunnel commissioners, and the manner in which he has managed the trust committed to him. the subdivisions of these subjects are:-- st. tunnel legislation. d. abuse of mr. brooks. d. power drills. th. the deerfield dam. th. "porridge." th. the western compared with the tunnel line. th. the possible capacity of the western road. th. the cost and time required to complete the tunnel. it is not our purpose to expose _all_ the misrepresentations and perversion of facts to which mr. bird has resorted in the treatment of his subject; but only enough of them to show what disreputable means the foes of the tunnel are capable of using in order to deceive the community. late results in the progress of work at the mountain, and in the perfection of machinery, will enable us to illustrate the utter absurdity of several of the most important of mr. bird's calculations, or rather speculations, and enable the reader to judge what reliance can be placed upon any of them. in a review of the history of tunnel legislation, as given in this pamphlet, passing by the frequent charges of "packed committees," "deceived legislatures," and "tricks of legislative legerdemain," we come to an account of the act of april, , by which it appears that the bill passed was not materially different from that prepared by mr. bird, and offered by mr. swan. it was _entitled_, "an act for the more speedy completion of the hoosac tunnel," yet the anti-tunnel league considered its passage "a substantial defeat of the scheme," because they believed that governor andrew "was opposed to the tunnel," and would appoint commissioners whose opinions were in harmony with his own. and the virtuous and honest member of the "third house," through whose adroit management, a bill bearing a title so inconsistent with its purpose, was framed, affects a pious horror of legislative trickery! whatever mr. bird may have to say upon any of his various topics, he never forgets to abuse mr. brooks; "_carthago delenda est_" at any rate; and he returns to the assault at the beginning or end of almost every chapter, with renewed spitefulness. on page it is represented that mr. laurie, the engineer who had been designated by the governor and council to make surveys, had a personal interview with mr. brooks, and that the following colloquy took place:-- "i am here, mr. brooks, to make the surveys ordered." "what order? what surveys?" "the surveys ordered by the governor and council." "i have ordered no surveys and want none. when i need your services i will send for you. go about your business." even those who have never reckoned mr. bird a man of strict veracity will be surprised to learn that this story is a pure fabrication, that no such conversation, and no such interview ever took place. the communications between the two gentlemen were a letter from mr. laurie, who was at hartford, and a reply by telegraph from mr. brooks, who was in boston. mr. laurie wrote,--"presuming that you wish me to make these surveys, i will come to boston," &c. mr. brooks telegraphed,--"the new survey has not been acted upon by commissioners." on the same page of the pamphlet it is stated that mr. brooks, not being satisfied with mr. laurie's conclusions, "demanded the suppression of some portions of the report, and the modification of others." "mr. laurie, after making such concessions as he could honestly make, resolutely refused to yield to mr. brooks' imperious demands upon material points." now' this representation is just as false as the story about the colloquy. mr. brooks did not make any such demands. an exposure of both these fabrications is made in a communication to the boston advertiser of march th, which contains copies of all the correspondence on these subjects, between mr. brooks and mr. laurie. on page , we are requested to "look at the item of the amount of the people's money applied by _mr. brooks_ to the payment of mr. haupt's debts," than which "there never was a more atrocious swindle." by referring to the records of the executive council for may, june and july of , it will be seen that the subject of paying these claims was referred to a committee of the council, consisting of alfred hitchcock, f. w. bird and joel hayden for special investigation. upon the question of the meaning and intent of the act of , and its legal interpretation, the committee took counsel of dwight foster, emory washburn, and isaac r. redfield, lawyers who had been designated by the governor, as a commission to whom should be referred such questions upon legal points as might arise in prosecuting the work, and in accordance with the advice of these gentlemen, and their own convictions, a majority of the committee (mr. bird of course opposing) reported that the claims ought to be paid. a majority of the council and the governor being of the same opinion, the claims were paid. the part performed by mr. brooks and his associates was merely to audit and allow them. they could not draw a dollar from the state-treasury for any purpose except upon the governor's warrant. _if_ the payment of these claims was "an atrocious swindle," then the governor, a majority of his council, and the three lawyers, as well as the commissioners, were the atrocious swindlers. it would appear that the incorruptible and virtuous bird was the only person about the state house, at that time, who could make any pretension to honesty or fidelity. the motives of mr. bird, in these unscrupulous attempts to disparage the judgment and asperse the character of mr. brooks are best known to himself, but it will be remembered that when mr. brooks received his appointment he was thought to be opposed to the tunnel enterprise. he has proved to be one of its ablest and most resolute friends. the disappointment and grief of mr. bird may have been rendered more poignant by his defeat last fall as a candidate for the honor of representing his district in the legislature, a defeat which he has publicly attributed to the opposition of mr. brooks. the only noteworthy thing in this pamphlet concerning the deerfield dam, is an absurd attempt to misrepresent the commissioners' report of its cost. they state that it is $ , . . it was finished last fall. mr. bird says "the dam will have cost when finished, at least $ , ," and thereafter to the end of his chapter on that topic, assumes that sum to be the actual cost. he obtains these figures by adding to the real cost of the dam, that of all the canals; buildings and machinery which are being constructed between the dam and the tunnel. he might, with equal propriety, have added the cost of the walpole meeting house, or that of his own paper mill. in a supplementary note we are informed that the dam across the connecticut at holyoke, feet long, cost about $ , . we may assume that mr. bird applies these figures to the present dam, and not to the one which gave way some years since. the cost of the first dam is not given, and the inquisitive reader might ask what that was, or whether the $ , should not with more propriety be considered as an expenditure for repairs of an old dam rather than the cost of a new one. however that may be, the cost of labor and material at the time the new dam was built, or the old one repaired, was less than one half of the cost of labor and material, at any time since the deerfield dam was commenced. it is possible that a cheaper structure might have been built, which would answer the purpose, but the commissioners and their engineers, warned perhaps, by the holyoke disaster, may be excused for constructing a work that will not be washed away, though done at some additional cost for its security. if there is one thing which mr. bird absolutely loves it is "porridge," and he returns to this topic with great vivacity. it may be briefly stated that in december last, after the heading from the west portal had been carried forward feet, progress was stopped by an inlet of water from a brook overhead and a spring below. this water operating on the rotten rock, produced what mr. bird calls "porridge." it was a difficulty which had been foreseen, but was never regarded by the commissioners or engineers as of a formidable character. soon after work was suspended at this point, responsible parties came forward with an offer to construct an arch lined with solid masonry through the "porridge" to the western shaft, a distance of about feet, for less than $ , ; and to furnish satisfactory security for the performance of their contract. the offer was declined. when mr. bird learned that work at this point was suspended, he became jubilant. he has filled ten pages of his two pamphlets with "porridge," and excited some fears on the part of his friends that the stuff has found access to the thinking part of his own person, and "muddled" it badly. but of this the reader may judge by noting on page of the last pamphlet an assertion that the distance from the west portal to the shaft is all demoralized rock; and on pages and a calculation that it will cost $ , , _in gold_, to construct this section of feet! but "porridge" is unreliable, and that at the hoosac, has given out; and so mr. bird's hopes and calculations, which were based upon it, fall to the ground. work has been recently resumed, and twenty-seven feet beyond the point at which it was discontinued, solid rock was reached, in which the workmen are now drilling and blasting without molestation or fear of "porridge." the brook is passed, and in the artesian well about half way from the portal to the shaft, solid rock has been reached at feet above grade. "porridge" has served its friends a mean trick and "well might _mr. bird_ exclaim in the language of woolsey (slightly altered,)" "had i but served _the truth_ with half the zeal i served my _porridge_, _it_ would not, in my need, have left me naked to mine enemies." the theoretical capacity of the western railroad is a fruitful subject for speculations and array of figures, but facts and demonstrated truths are what practical men wish to deal with. a comparison of the tunnel and western lines is of no significance, when both are urgently needed. in , when the western road was opened to albany, it transported from albany to boston , tons of freight, and last year, only , tons, tons less. yet in it had no double track, and in it had miles of double track. the greatest tonnage was , , in : and that same year, , tons of through eastward freight arrived at albany and troy, and the total amount to those two points was , , ; nearly three fourths of which was transported on the erie canal, an institution which is entirely left out of mr. bird's calculations. more than six million tons of freight were brought from the west last year to the hudson river. of this vast amount only a little more than one sixtieth found its way to boston over the western road. in , , tons of freight were transported from albany and troy to boston by the circuitous routes we have mentioned. mr. bird makes a calculation that the capacity of the western road can be so increased, by finishing the double track, increasing the rolling stock and adding special auxiliary force to draw its freight trains up the steep grades, that it can bring , , tons of freight in a year. it may be presumed that he means both local and through freight. but his "calculation" is as baseless and flimsy as any of his numerous statistical bubbles which have already been pricked. the best answer to his whole argument is contained in a memorial of the albany board of trade to our legislature, with some extracts from which, our review of this topic will be closed. but a few more of mr. bird's misrepresentations must first be exposed. on page he represents mr. brooks as claiming that the whole through freight from the west to boston_ eight years hence_, will amount to , tons. this estimate was made three years ago, and the words "eight years hence" were used at that time, and not now, as mr. bird represents. on page , is a list of names purporting to have been taken from the original subscription list of stockholders in the troy and greenfield railroad. mr. otis clapp is represented as having subscribed $ in "services;" and daniel s. richardson's name is appended, with ciphers and exclamation points. the first of these misrepresentations has been exposed by mr. clapp, who writes to the boston advertiser that he never charged the company for any service, nor was ever credited by them for services, but that he did subscribe and pay $ . for stock of the road. mr. richardson also writes to the advertiser, and mildly suggests that he was never in any way connected with the troy and greenfield railroad. on page , e. h. derby is represented as being president of the fitchburg railroad a pure fabrication; and alvah crocker as having "large investments" in the same road, when its books show that at that time he owned but six shares of stock. the truth is, mr. bird has no hesitation or scruple in using other people's names in the same manner as he uses figures and statistics in his calculations. mr. bird says lie never had any communication or correspondence with, and never received a dollar from, any person connected with the western railroad. that may be; but it is well known that mr. d. l. harris, president of the connecticut river railroad, has been for years the "_fidus achates_" of mr. bird in "fighting the tunnel," his colleague in the "third house," his companion at the hoosac mountain, and the guide of his inexperienced feet in the wilderness of facts and speculations of civil engineering. it is not so well known, but nevertheless true, that mr. harris is made director and president of the connecticut river railroad by the influence and vote of chester w. chapin, president of the western road. his zeal in the service of his benefactor has been manifested by an active hostility to the tunnel, as persistent and unscrupulous as that of mr. bird; and, were it possible for that gentleman ever to act from other than disinterested motives, or a sense of public duty, his intimate relations with mr. harris might justify a suspicion that the "sinews of war" might be supplied through that channel. at all events, we may be permitted to say that, if these two men have organized and led the opposition to the tunnel every winter for the last ten years, printed thousands and thousands of pamphlets, and spent a considerable part of each year in the lobby, and all this at their own cost, from a sense of public duty, then they have better deserved statues in front of the state house than webster or mann; and the western railroad management is even meaner than it has been generally considered. a corporation must indeed be without a soul, which can look upon such sublime virtue, and suffer it to pay its own expenses. but enough of mr. bird and his motives. the statements we have made in regard to the necessity of a new route are, in every particular fully confirmed by a memorial which has been recently addressed to our legislature from the albany board of trade, through a committee of seven of their number. the gentlemen comprising this board are not theorists, but practical, clear-headed and reliable business men, who have been compelled by the urgent demands of yearly increasing business, to appeal to the people of massachusetts for aid and relief. from a table in their memorial, it appears, that, while the increase, during the last fifteen years, of miles of railroad in eleven other states through which western products press to the seaboard, averaged per cent, that of massachusetts was only per cent. but we proceed to quote from the memorial:-- "twelve years of experience have convinced us that the western railroad is wholly inadequate to the prompt, rapid and cheap transportation of the commodities so extensively consumed by the people of the new england states. to illustrate the diversion of trade from the natural route to boston via albany, occasioned by the incapacity of the western road to meet the wants of commerce, we call your attention to the article of flour. we collate our facts from reports of the boston board of trade and the official reports of the western railroad. in , the western road, according to its own report, transported from albany and troy to boston, one hundred and fifty thousand barrels less than it did in , nearly twenty years ago. during the thirteen years, including and , the average of its transportation of this article, per annum, between the hudson and boston was , barrels. for the same period, there were received in boston, via other and more circuitous routes, an average per annum of , barrels. the next four years, including and , the average per annum by the western road was , barrels. boston received from other routes an average, per annum for the same period, of , barrels. now, we hold that, by the natural laws of trade, most of this vast quantity of flour, which reaches boston in these roundabout ways, would have left the hudson river at albany and troy, had the requisite facilities for a cheap and rapid transportation been afforded. about one-fourth of the average quantity received in boston from other routes, for the four years named above, reached that place via the grand trunk railway and portland, aggregating , barrels. taking detroit as the starting point, the distance from there to boston via portland, is miles greater than the route to boston via albany. yet, owing to the inadequate railroad facilities between albany and boston, the consignors of this flour prefer to send it via portland, and pay the charges on miles of additional distance. what is true of the article of flour is equally true of all the staple commodities produced at the west and consumed by the new england states. large quantities were last year turned aside at rochester and other points in our own state, to say nothing of points west of buffalo, and sent to boston and contiguous localities via the new york and erie railroad. boston is even now receiving flour from albany, troy and schenectady, by way of rutland, a distance of some fifty miles further than by the western road. we have no words but of commendation for the noble work which your state is pushing with such energy to open a still shorter route to the hudson. we have no feelings of jealousy toward the new route, because it terminates in another city than albany; a healthy rivalry will do more than moral suasion, to wake up the old route from that lethargy which seems so near akin to death. had the hoosac tunnel been completed twelve years ago, we have reason to believe it probable that the people of massachusetts alone would have saved an amount in the way of cheap transportation, nearly if not quite sufficient to equal its cost. we have spoken more freely in this paper than might be considered becoming in us, but for the fact that in the day of its need, albany, along with massachusetts, came to the aid of the western railroad. and now that we are suffering so much from its insufficiency to meet the public want, we trust the presentation of these views and facts will not be regarded as obtrusive, but rather as properly coming from those, who, with you, aided to produce a common benefit, and are now suffering with you from a common cause." the cost of the whole work was estimated by the commissioners in their first report, at $ , , , the estimate being based upon ordinary labor at one dollar a day, and of materials at a corresponding rate. nothing has yet occurred to invalidate this estimate, excepting the advance of the cost of material and labor, an incidental misfortune common to every public, as well as private enterprise, requiring labor and material, which has been prosecuted during the last three years. it is certain that these high rates will greatly decline, perhaps nearly to their former level within a year; but admitting that the commissioners' estimate should be swelled through these incidental causes to the sum of eight millions, would such an increase of expense justify the abandonment of this great enterprise, upon which so much has already been expended, and at the very period in its progress when the most formidable obstacles in its way have been surmounted, and its success become a certainty? had the western railroad been utterly destroyed last year by a rebel raid, as were some southern roads by the march of sherman, or by any conceivable cause, would the consideration of twenty-five, or thirty, or even forty millions, prevent its being rebuilt at once? why then should two millions stand in the way of the tunnel line, which is now a greater necessity than the western road was at the time of its construction? the time required to complete the work, without the aid of machinery, was estimated by the commissioners at eleven years and four months; and with the aid of such machine drills and power as had already been applied with success at mt. cenis, at seven years and a half. the work at mt. cenis was commenced in , and up to july, , feet had been excavated by hand labor; the machine drills were then applied, and the italian government has recently announced that the work will be finished by the close of the year . it will be seven and a half miles long. the hoosac tunnel will be about four and a half miles long, and at the present time it has been excavated feet, and shafts have been sunk to the depth of feet. the machine drills will be applied in a few days; but they are drills which will do twice, and possibly three times the work of those at mt. cenis. to the sound judgment, energy, and untiring perseverance of mr. brooks, and the inventive genius and skill of mr. stephen f. gates, of boston, and mr. charles burleigh, of fitchburg, belongs the credit of perfecting a pneumatic drill, by means of which our great tunnel will be completed much within the time named by the commissioners, and with a reduction of their estimate of its cost by hand labor of several hundred thousand dollars. we have seen this drill operated by compressed air, at the rate of two hundred blows a minute, each blow given with a force of more than five hundred pounds, cut an inch and a quarter hole in a block of hoosac rock, thirty-eight inches in thirteen minutes, without changing its points. its superiority over the mt. cenis drill consists in its lightness, automatic feed, and smaller size. the mt. cenis drill is eight feet long, and weighs six hundred pounds, and the whole machine moves forward in feeding. the hoosac drill is four feet long, weighs two hundred and eight pounds, and can be handled by two men. in feeding, the drill alone advances, and in such manner as to accommodate itself to any kind of rock it may encounter, whether hard or soft. its points are sharpened in a die by half a dozen blows of the hammer. it will do the work of twenty men; and, finally, sixteen of them can be applied to a surface upon which only nine of the mt. cenis drills can be used. the operation of this drill has already been witnessed by hundreds of persons, among them machinists, engineers, and stone masons, and not one of them entertains a doubt that it will do all which is claimed for it by the inventors. but the carriages are nearly ready, and these little machines will shortly be put to their work. the friends of the tunnel have no fears of the result. * * * * * massachusetts has always led her sister states. at the call to arms, her sons have been first in the field, and first to die for the common good. her schools and colleges, her institutions of charity, and her statutes have furnished models for the new states of the great west, and for foreign republics. in her manufactures and mechanic arts, in the products of her inventive genius, in maritime enterprise, in the building of canals and railroads, and in every undertaking to develop the resources and promote the prosperity of the country, she has been first and foremost. with so proud a record, and with almost exhaustless means at her command, we do not believe our noble state is yet ready to abandon the lead; nor that the consideration of a few millions of dollars will prevent her from breaking down the barrier which divides us from the west, and by which the great stream of western traffic has been so long checked and diverted. rather let us trust that, by wise legislation, a liberal policy, and a cordial support of the gentlemen to whom the conduct of this enterprise is entrusted, the great work of de witt clinton will be perfected, and the noble design of loammi baldwin executed, by the completion of the hoosac tunnel, before it shall be announced from sardinia that the alps are pierced and france and italy have joined hands under the grand vallon. [transcriber's note: table of contents was added.] minority report of the committee on railways in relation to the hoosac tunnel and the railroads leading thereto, with a bill to incorporate the state board of trustees of the hoosac tunnel railroad; also the speech delivered by hon. e. p. carpenter, in the senate of massachusetts, june , , in support of the same. boston: wright & potter, state printers, no. province street. . table of contents page minority report the bill speech efforts to reduce the transportation tax. the effect in our existing system. the relative advantages of boston and new york. the effect on the state of making boston an exporting city. the hoosac tunnel. position of the committee. the bill of the majority. regulation by special legislation. control of the tunnel. the purposes of the minority. the minority bill. the effect of state control of the tunnel line. the popular feeling in favor of state control. safety of the experiment. the alleged danger of political corruption. state pensioners. the benefits of the proposed plan. commonwealth of massachusetts. house of representatives, april , . the undersigned, members of the committee on railways, to whom was referred "an act to provide for the consolidation of the hoosac tunnel line of railroads from boston to troy," and the petition of the boston and lowell railroad company for amendment of the charter of the great northern railroad, and many petitions and remonstrances relative to the disposal of the troy and greenfield railroad and hoosac tunnel, respectfully submit a minority report: the committee, after public notice to all parties in interest, commenced its hearings upon the subject-matter of these petitions on the twenty-ninth day of january, and finally closed them on the twenty-first day of march. under the authority granted by the legislature, a reporter was employed by the committee, by whom it verbatim report was made of all the testimony and arguments submitted to the committee. this has been printed for the use of the committee and of the legislature, and is now accessible to members. many parties were represented by counsel, and various plans were presented. the first proposal was that of the troy and boston, and vermont and massachusetts railroad companies, for a consolidation under one corporation of the direct line between boston and troy. the second, for a consolidation of the boston and lowell and fitchburg railroad companies, with authority to lease or purchase the lines to the tunnel and to ogdensburg, placing under the control of one corporation about fifteen hundred miles of railroad. third, the proposition was urged upon the committee to provide for the acquisition by the state of the tunnel line. the attendance before the committee was not limited to the representatives of corporations directly or indirectly interested in the result. committees of the board of trade and other commercial associations, and many private citizens to some extent represented the public interests; while the larger audiences in attendance upon the sessions of the committee attested the deep interest of the business community in the subject-matter under discussion. the problem before the committee was to determine how the people of this commonwealth could derive the greatest benefit from the construction of the tunnel which has involved so large a public expenditure. the relations of the state to this enterprise have greatly changed since its commencement. the tunnel was projected as a private enterprise, which was first aided by the state by a loan of its credit. it was doubtless then intended that the tunnel when completed should form a part of the through line over the fitchburg, vermont and massachusetts, troy and greenfield, and troy anti boston railroads, to be owned and controlled by these corporations like the rest of the line. this project failed. the troy and greenfield railroad company was unable with the state loan to complete the tunnel, and after great delays and difficulties, surrendered its railroad and the incomplete tunnel to the commonwealth, which has since carried on the work at the public charge. its completion within the current year may be expected, and the total expenditure from the treasury of the state will amount, including interest, to about $ , , . this expenditure is a charge upon the people and the property of the whole state. it seems improbable that any disposition can be made of the tunnel which can return to the treasury the whole sum expended, and it is for the legislature to determine how far a return can be made to the people of the state from this great public expenditure, in increased means of transportation and a reduction of rates which are now a burden upon the whole community. since the tunnel was projected, new lines of railroad have been built which give to nearly every portion of the state direct access to the tunnel and through it to the great west. in the progress of the hearing certain points were made tolerably clear. _first_, that the tunnel itself should be so far held and controlled by the state as to insure its use on equal terms by all parties. _second_, that some consolidation of the line or lines working through the tunnel was essential to secure efficiency of action, and to provide for the great business awaiting the completion of the tunnel. _third_, that to provide equipment and terminal facilities for such a business, the weak and disjointed separate corporations were inadequate, and that it was particularly desirable that some action should be taken at the present session of the legislature. the policy of direct state ownership was strongly pressed upon the committee by the railroad commissioners and other parties. the address of mr. adams, in behalf of the commissioners, upon this subject, is contained in the printed report, and is a clear and able statement in behalf of this policy. while the experiment has been tried in other states, and under other circumstances has failed, we do not think it is to be condemned for this reason. these experiments were tried before the development of the railroad system, and generally in thinly-peopled states, where state construction of railroads was a political necessity to supplement private capital that could see no inducement for investment. in the days when state management failed, corporation management failed to quite as great an extent. the statement of mr. adams, in regard to the results of the system in belgium, are very striking, and in england the current seems to be settling in favor of the assumption of the railroads by the government. to any careful observer of the railroad development of the past twenty-five years, there can be little doubt of a like progressive increase in this business in the future. if the benefit of this increase in business can be secured to the people who furnish the traffic, instead of to the corporations who provide the capital, an immense public benefit will follow. the most valuable experiment to be tried at the present day is to ascertain how cheaply railroad transportation can be afforded. corporations formed to make money for their stockholders, can hardly be expected to fairly try this experiment. the greatest need of this commonwealth is cheap transportation. to secure this the hoosac tunnel has been constructed at a cost of $ , , of public money. we are fully convinced that to secure to the people the full advantages to be derived from the construction of this new avenue to the west, and to secure equal lights to all parties desiring to use it, the state must not part with the control of the tunnel. we are equally convinced that to secure efficiency in the lines working through the tunnel, consolidation is necessary, and that the tunnel itself must be worked and managed for all parties using it, by one head. it would follow that the state, retaining the tunnel, should operate it, and should also own or control one line of road between boston and the west, at the same time giving to all parties, without discrimination, equal advantages to the tunnel. the state management cannot afford to be unjust or to discriminate. no private corporation can be trusted when its own interests may conflict with the interests of other and perhaps rival corporations, to establish or to enforce rules for the transaction of such business. we therefore report and recommend the passage of the accompanying bill: "to incorporate the state board of trustees of the hoosac tunnel railroad." its purpose is to form a corporation for the management of the troy and greenfield railroad and hoosac tunnel, with all the powers of a railroad corporation. it is to be composed of five trustees, to be appointed by the governor and council, each to hold office for five years, and one of whom shall be appointed annually. to these five state trustees are to be added not exceeding three, one by each of the railroad corporations whose property may be acquired or managed under the terms of the act. instead of directly purchasing the railroads constituting the direct line, provision is made for leasing these railroads by the new corporation upon terms which are fair and equitable for all parties. the returns to the railroad commissioners show that the average expense of operating the railroads of this state is seventy-five per cent. of the gross income. we therefore propose to set apart for the benefit of each of these corporations twenty-five per cent. of the gross income of its railroad, out of which shall be paid a yearly rental; and that they may not in any event be losers by the experiment, it is proposed to guarantee to them an amount sufficient to pay to their stockholders the dividends they are now paying, with liberty to increase to the maximum which law or custom permits our railroad corporations to pay. that such a lease would receive the assent of the companies interested, we have strong reasons to believe. it secures to the stockholders the dividends they are now receiving. it secures also to them the benefit of any increase of business likely to accrue from the completion of the tunnel, to as full an extent as they can hope to benefit by it. no railroad corporation ought ever to pay more than ten per cent. dividends, and the legislature would undoubtedly, under its power to regulate tolls, interfere to prevent greater dividends. while these corporations are thus interested in the earnings of the roads, the bill provides that they should be represented in their management. we shall thus secure the services of persons familiar with the local business and history of the separate roads, and although forming only a minority of the board of management, they must have an important influence in the direction of its affairs. the benefits to be gained by the state by this arrangement are obvious and manifold. it retains state ownership and management of the tunnel. it secures to all corporations desiring to use the tunnel equal rights. it secures to the commonwealth the full value of its investment, whatever future developments of business shall prove that value to be. it assumes the establishment of a strong corporation, able to provide all equipment and terminal facilities which any future increase of business may render necessary or advisable. it meets all the presumed advantages of state acquisition of the railroads, without that disturbance and removal of capital which must follow the purchase of the railroads by the state. it can furnish capital for the improvement of the line at a cheaper rate than any consolidated company can procure it; and cheap capital in disinterested hands secures cheap transportation. it enables the state to try fairly and fully the experiment of cheap transportation. it creates a corporation which cannot combine with other corporations, nor can its stock be purchased or in any way controlled by outside parties, and is strong enough to compete successfully with the powerful corporations of neighboring states. such a management we believe would be efficient and reliable beyond that of ordinary railroad corporations. it would combine to a great degree the advantages of state and corporate management. the governor and council could be depended upon to appoint suitable persons as trustees. the railroad corporations would naturally appoint their most efficient agents as trustees. such a board could find no difficulty in securing the services of the ablest railroad officers to direct and aid in the management. it remains to refer briefly to the other propositions before the committee. first, to that of the boston and lowell railroad company to unite with the fitchburg. this is a proposal to unite two lines in some degree rival and competing. they are rival lines to some extent for local business. they form parts of rival lines for distant business with the north and west. it is a new proposition in this commonwealth to unite rival and competing lines. this competition will be increased with the opening of the tunnel line. the lowell is the natural terminus of the northern line, and the fitchburg is the natural terminus of the tunnel line. whatever advantages may accrue to the corporations themselves from such a consolidation, the public results will be unmitigated evil. not one witness unconnected with the interested corporations appeared before the committee to testify in favor of such a consolidation. the evidence against it was strong and conclusive. the northern line by way of the lowell and vermont central was shown to be of great value to boston and to massachusetts. it is now in a measure consolidated under contracts having twenty years to run, and it is surely bad policy for the commonwealth, having expended $ , , to create a new line, to commence its operations with the destruction of one in full and vigorous existence. moreover, such a consolidation threatens more than anything else state control of the tunnel itself. a powerful corporation, owning the whole line except the tunnel, would soon compel the transfer of that, and until such transfer, would throw upon the state as the owner of the tunnel the responsibility for all the sins and omissions of the line. the important question of an interchange of depots and tracks by the railroads entering boston on the north has been somewhat involved in this hearing. the avoidance of railroad crossings is undoubtedly of great importance, but it has no proper connection with the disposal of the tunnel. the eastern railroad company and boston and maine railroad are agreed what changes can and should be made to avoid these crossings. all that is essential to secure this end is to remove the passenger station of the fitchburg railroad west of the lowell, where it properly belongs. the legislature has full power in the premises. it can, independently of any consolidation, require the fitchburg railroad company to provide passenger accommodations west of the lowell station, and thus leave its present station on causeway street free for the use of the eastern railroad company. if the state acquires the fitchburg railroad under this act, it can easily provide for the change. the whole question of interchange of depots is independent of the far more important question of the disposition of the tunnel, and should not control it. if the lowell railroad can provide for the wants of the fitchburg railroad company in its passenger station after consolidation, it can do so without consolidation. respectfully submitted by e. p. carpenter, j. k. baker, t. w. wellington, william baker, _members of the committee on railways._ commonwealth of massachusetts. ------------- in the year one thousand eight hundred and seventy-three. ------------- an act to incorporate the state board of trustees of the hoosac tunnel railroad. _be it enacted by the senate and house of representatives, in general court assembled, and by the authority of the same, as follows:_ sect. . the governor, with the advice and consent of the council, shall, as soon after the passage of this act as may be convenient, appoint five persons, citizens of this commonwealth, who shall, on or before the first day of july next, take the interest of the commonwealth in the troy and greenfield railroad, and the hoosac tunnel when it shall be completed by the contractors, and all the property and interest of the commonwealth in the southern vermont railroad company, and hold the same in trust for the purposes hereinafter named, one of whom shall hold his office for five years, one for four years, one for three years, one for two years and one for one year, from the ___________ day of ___________. before the first day of july in each year, one such trustee shall be appointed for the term of five years; upon the occurrence of a vacancy before the expiration of a term, an appointment shall be made for the remainder of such term. sect. . said trustees are hereby created a railroad corporation under the name of the state board of trustees of the hoosac tunnel railroad, and shall have all the powers and privileges, and be subject to the duties, restrictions and liabilities set forth in the general laws relating to railroads, so far as the same may be applicable and not inconsistent with the provisions of this act. sect. . before entering upon their duties, said trustees shall be sworn to the faithful performance of the same. they shall organize by the election of a president, who shall be one of said trustees, a clerk and such other officers as shall be necessary, and they shall prepare by-laws in accordance with which their meetings shall be held. sect. . said board of trustees shall have sole charge, direction and control, subject to the provisions of this act, of the troy and greenfield railroad and of the hoosac tunnel, when said tunnel shall be completed by the contractors of the southern vermont railroad, and of such other railroads as may be leased or acquired under the provisions of this act. they shall appoint a treasurer, a general manager, whenever they deem such an officer necessary, one or more superintendents and such other agents as may be required for the operation of said railroads and tunnel, and they shall define the duties and fix the compensation of such officers and agents. they shall establish rates for the transportation of passengers and merchandise, and make contracts and arrangements with connecting roads in relation to joint rates and joint business, and they may do all other things, not inconsistent with the provisions of this act and the general laws in relation to rail roads, which may be necessary for the efficient and economical operation of said railroads and tunnel. sect. . said board of trustees shall hold in trust all moneys received from the operating of said railroads and tunnel, and all moneys which may be appropriated by the commonwealth for the completion, extension and improvement of said railroads and tunnel and for the equipment thereof, and shall faithfully apply the same. they shall annually pay into the treasury of the common wealth the net income received from said roads and tunnel after the payment of the expenses; and the same shall be set apart, under the direction of the governor and council, and applied in such manner and at such times as they shall direct to either or all of the following purposes: the extinction of any indebtedness, or payment of interest thereon, which the commonwealth may at any time incur to carry out the purposes of this act, or any act in addition to or amendment thereof; the extinction of the indebtedness, or payment of interest thereon, which has been or may be incurred in the construction of the hoosac tunnel; and the purchase of stock in any company which shall lease its franchises, railroad and property in perpetuity to the corporation herein before created. sect. . said board of trustees shall make a semi-annual report to the governor and council of their doings during the six months next preceding, and of their receipts and expenditures, and shall make an annual report to the board of railroad commissioners in the manner and form and at the time prescribed for railroad corporations. sect. . said trustees shall receive, in full compensation for their services as such, the sum of five thousand dollars each per annum, except the president of the board, who shall receive eight thousand dollars, which sums shall be charged to operating expenses. no trustee shall be appointed to any office in the employ of said board of trustees, except the president, but the general manager, when such officer shall be appointed, shall be _ex officio_ a member of the said board. sect. . said board of trustees is hereby authorized to re-locate, where necessary, the tracks of said troy and greenfield railroad, taking land therefor in the method prescribed by law in case of land taken for depot or station purposes, and to complete, extend and improve the construction and equipment of said railroad and tunnel, and to prepare the same in all respects for the reception of the traffic of a through line. sect. . the sum of five million dollars is hereby appropriated, to be expended under the direction of said board of trustees in carrying out the provisions of this act, to be paid to them from time to time as the same may be required and called for, by a two-thirds vote of said board of trustees, on the warrant of the governor. and for the purpose of providing for said appropriation the treasurer of the commonwealth is hereby authorized to issue scrip or certificates of debt in the name and on behalf of the commonwealth to an amount not exceeding five million dollars, to be sold or disposed of in such manner, and at such times, and in such amounts, as the governor and council shall direct. such scrip shall be redeemable in not less than twenty nor more than, forty years from the date thereof, shall bear interest not exceeding six per cent. per annum, payable semi-annually, and shall be known as the "hoosac tunnel railroad loan"; and the property of the commonwealth in the troy and greenfield railroad is hereby set apart and pledged to the redemption of said scrip. sect. . said board of trustees is hereby authorized and directed to lease in perpetuity, or for such term of years as the governor and council may approve, the franchises and property, and thereafter to maintain, improve and, operate the railroad, with its branches, of the vermont and massachusetts railroad company, on the terms following: twenty-five per cent. of the gross earnings of said leased railroad and property shall be reserved annually by said board of trustees as a specific fund out of which they shall pay to said company, first, a sum sufficient to pay the interest on the indebtedness of said company, at the date of said lease, as said interest becomes due, and, second, a yearly rental equal to ten per cent. on the present capital stock of said company, free of all taxes upon the stockholders or said company (and on any additional stock, when the same shall be issued for existing convertible bonds), or such a proportion of said rental, not exceeding said ten per cent. and said taxes as said reserved fund shall be sufficient to pay: _provided_, _however_, that in no year shall there be paid to said company a rental of less than four per cent. on said capital stock, and said taxes together with the amount of said interest; and to the payment of such minimum rental and interest said board of trustees is authorized to pledge the faith of the commonwealth. said board of trustees is also authorized to assume and make provision in said lease for the payment of the principal of said indebtedness. the surplus of said reserved fund shall be annually passed by said board of trustees to the account of earnings. when said lease shall have been executed, and while the same continues in force, said vermont and massachusetts railroad company may elect, from time to time, for a term not exceeding five years, one trustee, who shall be added to said board of trustees, and, upon being sworn to the faithful performance of his duties, shall become an incorporated member of the state board of trustees of the hoosac tunnel railroad; and said company may fill vacancies for the remainder of the term. sect. . said board of trustees is hereby authorized and directed to lease in perpetuity, or for such term of years as the governor and council may approve, the franchises and property, and thereafter to maintain, improve and operate the railroad, with its branches, of the fitchburg railroad company, on the terms following: twenty-five per cent. of the gross earnings of said leased railroad and property shall be reserved annually by said board of trustees as a specific fund, out of which they shall pay to said company a yearly rental equal to ten per cent. on the present capital stock of said company, free of all taxes upon the stockholders or said company, and also on an additional capital stock of one hundred thousand dollars, which said company is hereby authorized to issue and hold for its own benefit, or such a proportion of said rental, not exceeding said ten per cent. and said taxes, as said reserved fund shall be sufficient to pay: _provided_, _however_, that in no year shall there be paid to said company a rental of less than eight per cent. on said capital stock and said taxes; and to the payment of such minimum rental, said board of trustees is authorized to pledge the faith of the commonwealth. the surplus of said reserved fund shall be annually passed to the account of earnings. when said lease shall have been executed, and while the same continues in force, said fitchburg railroad company may elect, from time to time, for a term not exceeding five years, one trustee, who shall be added to said board of trustees, and, upon being sworn to the faithful performance of his duties, shall become an incorporated member of the state board of trustees of the hoosac tunnel railroad; and said company may fill vacancies for the remainder of the term. sect. . said board of trustees is hereby authorized and directed to lease the franchises and property, and thereafter to maintain, improve and operate the railroad, with its branches, of the troy and boston railroad company, and shall pay therefor an annual rental equal to twenty-five per cent. of the gross earnings of said leased railroad and property. when said lease shall have been executed, and while the same continues in force, said troy and boston railroad company may elect, from time to time, for a term not exceeding five years, one trustee, who shall be added to said board of trustees, and upon being sworn to the faithful performance of his duties, shall become an incorporated member of the state board of trustees of the hoosac tunnel railroad; and said company may fill vacancies for the remainder of the term. sect. . in estimating what shall constitute the said twenty-five per cent. of the gross earnings of said several leased railroads, out of which their rentals are to be paid, there shall be first deducted from twenty-five per cent. of their respective gross earnings, six per cent. per annum on all amounts expended by said board of trustees for the permanent improvement of said railroads respectively. sect. . said vermont and massachusetts, fitchburg, and troy and boston railroad companies are severally authorized to lease their franchises and property to said board of trustees. sect. . said board of trustees is further authorized, with the approval of the governor and council, to lease or purchase necessary terminal facilities, and also to lease any railroad now built, or that hereafter may be built, lying in the tunnel route between boston and lake ontario. sect. . in the carriage of through passengers and merchandise, the rates of transportation shall be estimated pro rata per mile, and the hoosac tunnel shall be estimated at such length in miles, not exceeding fifty, as shall seem equitable to the trustees. sect. . in the management of such railroads as shall come under the operation of said board of trustees, there shall be no unequal discriminations in freights, fares or facilities in favor of or against different persons, places or connecting railroads. sect. . in case of the lease of the fitchburg railroad under the terms of this act, the said board of trustees is authorized and directed to purchase terminal facilities in boston, westerly of the freight station of the boston and maine railroad and to arrange with the eastern railroad company for an interchange of stations in boston in such manner as to obviate the necessity of passenger trains on the eastern railroad, boston and maine railroad and fitchburg railroad crossing the tracks of the other, and the eastern railroad company is hereby authorized, with the assent of said trustees, to take or purchase all the land, depot property and buildings of the fitchburg railroad company, situated in boston south of the channel or passage-way for vessels through the fitchburg railroad bridge over charles river, said property to include all the draws and drawbridges over the passage-way for vessels. also all the property, land and buildings situated on the south-westerly side of the following line, to wit: beginning at a point on the northerly side of the above-mentioned passage-way for vessels twenty-two feet nine inches east of the easterly line of the roadway draw over said passage-way, and running northerly at right angles to said passage-way, one hundred and three feet five inches, to a point where said line intersects with the north-easterly line of said fitchburg railroad bridge over charles river; thence northerly, following and coinciding with said north-easterly line of bridge, eight hundred and forty-eight feet; thence turning and running westerly to a point in the north rail of the north passenger track of the fitchburg railroad, distant four hundred and sixteen feet seven inches from the south-easterly line of austin street, measured on said north rail of the north track. said point is also distant twenty-nine feet four inches at right angles from the southerly side of the wooden freight house (measured from a point sixty feet distant from the westerly end) belonging to the fitchburg railroad company, on front street; thence southerly, crossing the fitchburg passenger tracks at right angles to a point four feet distant south of the south rail of south passenger track; thence westerly on a curved line parallel with the south rail of the south passenger track, and four feet distant therefrom to the south-easterly line of austin street in charlestown. and if the eastern railroad company shall so fake the said property of the fitchburg railroad company, then the fitchburg railroad company shall take or purchase all the like property of the eastern railroad company lying between the crossing of the eastern and fitchburg railroads and causeway street in boston, except the parcel of land to be taken by the boston and maine railroad, as hereinafter provided; and in case of the taking or exchange of the tracks and property herein before described, or any part thereof, the said fitchburg railroad company shall locate and construct such tracks and bridge structures on the westerly side of the present line of the eastern railroad as may be necessary to connect its railroad and tracks with the tracks and property so purchased or taken by it; and shall not thereafter cross either said eastern railroad or said boston and maine railroad except for freight purposes. and the eastern railroad company shall locate and construct such tracks and bridge structures as shall be required to connect its present tracks northerly of its crossing with the boston and maine railroad with the tracks and property so purchased or taken by it, keeping at all times east of a line drawn from a point on the easterly side of its present location, distant southerly three hundred and fifty feet, measured on said line from its intersection with the southerly side of cambridge street to the point of intersection of the northerly line of the state prison wharf with the easterly line of the location of the boston and maine railroad, and thence keeping east of said easterly line of said location; and shall not thereafter cross the tracks of the boston and maine railroad. and the eastern railroad company shall take any lands now belonging to the boston and maine railroad in charlestown or somerville lying easterly of such new location; and the boston and maine railroad shall take all the road-bed, land and property of the eastern railroad company lying between the line above described for the westerly limitation of said new location of the eastern railroad and the westerly line of the old location of the eastern railroad, and the present northerly line of the fitchburg railroad: _provided_, _however_, that in case of the aforesaid taking and exchange of property by and between the eastern and fitchburg railroads, the boston and maine railroad shall release the eastern railroad company from all damages for its taking and occupation thereof and take from the said eastern railroad company so much of the premises described in the first section of the three hundred and fifty-sixth chapter of the acts of the year eighteen hundred and seventy-two, as was taken from the said boston and maine railroad by said eastern railroad company under the provisions of that act; and said eastern railroad company shall, without other compensation therefor, release to said boston and maine railroad all their rights in said premises acquired by them, taking the same under said act; and _provided_, _further_, that any exchange of land made under the provisions of this section shall take effect simultaneously. all general laws relating to the taking of land for railroad purposes and to the location and construction of railroads, shall be applicable to and govern the proceedings in the taking and exchange of lands and property, and in the making of any new locations under the provisions of the foregoing sections, except that instead of the county commissioners three disinterested persons shall be appointed by the supreme judicial court for the county of suffolk as a board of commissioners to determine the values of the lands and property so taken and exchanged or over which any such location may be made, and to adjudicate the damages to be paid by any of the others upon the taking, exchange or locations aforesaid, from whose decision an appeal shall be to a jury in behalf of either party, as provided by law in the case of lands taken for railroad purposes. any sum of money received by the fitchburg railroad in said interchange of stations and tracks above the expense of necessary alterations shall be applied to procuring new terminal facilities and making improvements on said road or may be applied to the reduction of the capital stock of the fitchburg railroad company in such manner as may be agreed between the fitchburg railroad company and said board of trustees. sect. . this act shall take effect upon its passage. speech. mr. president: i am deeply impressed with the great importance of the question now before us for consideration. it is not local, not sectional, nor political, but a question that affects more or less directly the industrial, the mercantile, the manufacturing, and the commercial interests of the whole commonwealth. the proper solution of this great problem rests with us, as the representatives of the people; and it is a responsibility of no ordinary importance, and one that should control our serious and earnest attention and our candid and best judgment, unbiased by any local or personal interest, with a solemn regard to our oaths to support and maintain the constitutional rights of the people of the commonwealth. stern convictions of duty alone induce me to address this honorable body on this occasion--duty that i feel incumbent upon me, mr. president, from the honored position that i received at your hands. it is well known that i neither have or make any claims as a public speaker, and i must ask your indulgence for being somewhat dependent upon my notes in presenting to you an honest statement of my own convictions of this great question, having no other interest to serve but the state and her people. this important subject involves directly the whole question of the railroad policy of this commonwealth; and here in massachusetts the proper direction of the railroad policy is even more important than at the west, where it now engages the public attention almost to the exclusion of other interests. within the last fifty years this commonwealth has almost entirely changed its industrial position. half a century ago, agriculture, the fisheries, and commerce were the leading interests. now, manufactures engross the attention of our people, and have made all other interests subordinate. they have not excluded other interests, but in a measure supplemented them. our agriculture has changed and now finds its chief support in providing supplies for the manufacturing towns which have grown up in every part of the commonwealth. our commerce, both internal and external, is largely engaged in bringing to our doors the raw material for our laborers, and in spreading throughout the world the products of our manufacturing industry. we can raise but a small proportion of the food necessary to feed the people of the state; under such circumstances the transportation must weigh heavily upon our industry. we feel it in the increased cost of living, which increases the cost of every article we produce. we feel it in the increased cost of the raw materials of our manufactures, which makes us less able to compete successfully with more favored locations. we feel it finally in the increased cost of marketing our goods. this position has been so well stated by the railroad commissioners in their report of , page , that i may repeat it here: "it may safely be asserted that there is no branch of massachusetts industry which is not carried on against competition more advantageously located. the state has very few natural advantages; but everything with her depends on the intelligence of her people, and the cost of transportation. the west, in producing cereals, has at least a soil of unsurpassed fertility: pennsylvania in manufacturing iron has the ore and the coal in close proximity to the furnace. the english mill-owner has his power and his labor in cheap profusion. almost every article, however, which enters into the industries of massachusetts has to be brought within her limits from a distance. her very water powers are subject to inclement winters and dry summers, while she has to make her ingenuity supply a deficiency in labor. her food is brought from the north-west: her wool and her leather from south america, texas, california and the central states: her cotton from the south: her ores from the adirondacks: her coal from pennsylvania; her copper from superior,--and the list would admit of infinite extension. massachusetts is thus merely an artificial point of meeting for all kinds and descriptions of raw material which is here worked up, and then sent abroad again to find a customer at every point, coming and going, and in process of manufacture, it has to be transported, and it has to bear all costs of transportation in competition with articles of the same description produced elsewhere and by others. every reduction of the transportation tax acts then as a direct encouragement to the industry of massachusetts, just as much so as if it were a bounty or bonus: it is just so much weight taken off in the race of competition." no words of mine can add any force to this plain statement of facts; but yet we are told that transportation is only _one_ element in the cost and price of goods, and frequently not that of the greatest consequence, but the importance of this _one_ element is fourfold, and often more, to the massachusetts manufacturer, making the transportation of more importance in many cases than the cost of materials transported. this transportation tax is the _very_ element that is to build up a competition in these favored localities that will either extinguish or transfer many classes of our industrial interests that we can ill afford to lose. it is only necessary for one to travel west and south and observe the great development and success of the manufacturing interest in these sections to be convinced that new england cannot long hold the prestige as the "workshop" of the country with so heavy a transportation tax imposed upon her industrial productions. the importance of this one element will be more fully realized by the eastern manufacturer when he finds that his southern and western rivals save it altogether by having the raw material at hand, and a home market with all the other elements (save skilled labor which can be transported) that make manufacturing industry profitable at a much less cost. a combination of our manufacturers to establish cheap transportation, and the sale of their goods upon a home market, would be far more to their interest and profit than the exaction of an extra hour's labor and would confer a great blessing upon their overtasked employees. efforts to reduce the transportation tax. since the railroad system was inaugurated in , the statutes of this commonwealth bear yearly evidence of the persistent and liberal policy pursued by the legislature toward the railroads. it would be tedious to enumerate the many acts which have been passed loaning the credit of the state to aid the struggling corporations in establishing and completing their lines. almost all the leading lines in the state sought and obtained this aid, without which there must have been a great delay, if not failure in accomplishing these enterprises; and here let me say, that with the exception of the hartford and erie loan, and the losses arising from the repayment by the eastern, and norwich and worcester railroads in legal tender instead of gold, there has never been a dollar lost by the railroad loans of the state. the result has been to build up a system of railroads, centering in the city of boston, having no superior, if equal, for completeness on this continent. massachusetts has more miles of railroad in proportion to population and territory than any similar extent of territory in america. and there can be no question that the prosperity of the state has grown more from its railroad facilities, than from all other causes combined. there is another class of legislation to which we cannot look with equal satisfaction. every railroad charter contains provisions for the regulation of fares and freights; and yet since the railroads were established, no single act has been passed directly for this regulation. the question has involved so great difficulties that no legislature has yet ventured to grapple with it. the tendency of legislation in that direction is obvious. commissioners have been appointed to consider the subject and no result has followed. a board of railroad commissioners has been formed, which has been productive of great good both to the railroad corporations, and to the people. this board has been directed to fully consider and report some plan of regulating fares and freights; and has reported that it cannot recommend any means of reducing this transportation tax, by direct legislation, but strongly advises the trial of state ownership, as the only means of attaining the desired end. the effect in our existing system. while it may be said that under the present system of railroads, the commonwealth has been prosperous, there are drawbacks and defects which need careful examination, and if possible a remedy. to those who are familiar with the condition of our manufactures, the most striking want is the failure of our home market for our productions. we are tributary to new york in many ways. the great sale of our manufactured goods is made in new york, and goes to build up a rival city. our great commission houses have been compelled to establish branches in new york, which in a short time have surpassed in business and in importance the home establishments. if we could have kept at home the sale of our manufactured goods--have retained here in boston the great houses through which the exchanges are made--could have brought to new england the purchasers from the west and south, it would have vastly increased the prosperity of boston and of new england. business can be done cheaper in boston than in new york; and yet new york has drawn away from us a large proportion of our legitimate business,--the sale of our manufactured goods; and this loss can be directly attributed to a defect in our railroad system, which can and should be remedied. i say defect, but, more properly, the want of a strong and independent line of railroad through to the west, controlled in the interest of massachusetts. why, mr. president, if we could withdraw from new york the firms and business that represent the sale of massachusetts goods, it would more than cover the burnt district of this city, and double the business of boston; and new york would feel that her loss was much greater than the boston fire. and why is it that our goods are sent to new york to be sold? simply because new york has _three_ great trunk routes to the west, which control the transportation of the southern and western productions, and the owners, who are the merchants, follow their goods, and are the customers who purchase our manufactured goods of new york houses, and ship them in return over these same trunk lines, giving them a large and profitable business; which should be and can be controlled, by proper management, in the interest and for the benefit of a through line or lines from boston to the west. to-day boston is without a through and independent line to the west, and while we are shipping our goods to new york to be sold, to be transported over the great lines leading south and west, our _own_ western road, so called, in , according to the annual report of the directors, carried through from boston to albany , tons of freight, and from albany to boston , tons--more than four times as much _from_ the west than is carried _to_ the west; which state of things would be reversed if the sale of our goods was made here instead of new york; but this can only be accomplished by a through line west, controlled in the interests of massachusetts, and not in the interest of new york. a line to the lakes in competition,--not with the boston and albany railroad, as that is dependent upon the new york central railroad in a great measure for its western freights,--but an independent line, so organized as to guard against any combination, that will force by competition the new york lines to give to the boston and albany and the boston, hartford and erie railroads less rates, making boston a competing point, thus securing the advantages of four competing western lines, including the great northern line, which must bring to our seaboard the products of the great west, and thus secure an exchange of trade that will increase the growth, and prosperity of massachusetts, that will equal the prophecies of those who are called _visionary theorists_. it was by competition of the three great trunk lines running to new york--discriminating against boston--that forced the removal of the sale of massachusetts productions to that city; and it is estimated these sales amount to more than two hundred and fifty millions of dollars per annum at the present time; and the golden opportunity is now at hand to restore in a great measure the advantages lost by not having a strong and efficient line of railroad leading to the great west, in the interest of the state. the relative advantages of boston and new york. the great advantages of new york arise from the fact that it is a great emporium of exportation and importation. a very large proportion of the exports of the country have been made from new york. she has gained control of the export trade--and the export trade governs the import trade. ships go where they can find a return cargo, and merchants follow their goods. the possession of the great bulk of the export trade, has given to new york the great bulk of importations, and equally the control of the domestic trade. how can we, in boston and massachusetts, get our fair share of the importing and domestic trade of the country? there is but one way--by reducing the transportation tax. in many respects boston has great advantages for the export trade. the chief exports of the country are to europe. we are two hundred miles nearer europe than any of the other of the great seaboard cities. we have a harbor unrivaled on the american coast for easy entrance--for depth of water--for protection from storms. its great water-front, at which vessels of burden may lie to an extent (as is stated by the harbor commissioners) of fifty miles--every foot of which is, or may be directly connected with our railroads. there is not a wharf along the whole circuit which may not, without great expense, be made available for the export of the productions of the country, brought by the railroad car to the side of the ship, which shall convey it to the freight market. if we can secure to boston a fair share of the export trade of the country, the import and domestic trade will follow, and we ensure the building of a city within the limits of my friend's annexation project, that will equal the greatest city of the continent. the effect on the state of making boston an exporting city. it is hardly necessary to allude to the close connection which boston holds to massachusetts. one-third of the population of the state and one-half its valuation are combined within a circle of five miles from this building. the prosperity of boston is inseparable from the prosperity of massachusetts. the recent calamity of boston was felt throughout the limits of the state. but the great benefit to the state from making boston an exporting city is not the prosperity of the city itself. it grows out of the condition which alone can make boston a city of export for the productions of the country. this can only result from a reduction in the transportation tax which will make such productions relatively cheaper in boston than in new york. in the profits of such a result the remotest corner of the state will directly share. transportation cannot be reduced to boston without a corresponding reduction upon every line of railroad leading to or from this city. it was with a hope of such a result that the state entered upon the project of building the hoosac tunnel, and it rests with us to say, now that this great enterprise is so near completion, whether this hope can be realized. the hoosac tunnel. it is needless to explain at any length what the hoosac tunnel is. there can be no member of this board who does not know that we in massachusetts are separated from the west by a mountain barrier extending from near long island sound to near the canada line. this barrier must be passed to bring us into connection with the west. it has been turned on the north by the vermont central, on the south by the hartford and erie. it has been passed over steep grades by the boston and albany. at north adams it is compressed into narrow limits in the hoosac mountain, and the bold conception was formed to pierce directly through it at this point. first, the effort was made to accomplish the great undertaking by private capital, aided by a state loan. the difficulties were underrated and the plan failed. finally, the state assumed the enterprise and has since, with varying fortunes but unfaltering energy, prosecuted it to a successful result. within the current year there can be little doubt of the completion of the work. the tunnel will be opened for traffic and a new line formed between boston and the west, shorter by eleven miles than any existing route; with easy grades, which, making the usual allowance for the obstruction caused by heavy grades to railroad traffic--will render it constructively shorter than any route by at least twenty miles, or ten per cent., between boston and albany. its cost to the state, including the troy and greenfield railroad, will be at least twelve millions, raised by loans, on which the interest is paid by taxation. since the plan of the tunnel was formed new lines of road have been projected and built, connecting it with every part of the state, and there is scarcely a town from berkshire to provincetown, which does not to-day stand in position to reap its share of the benefit expected to follow the completion of this great public enterprise. having expended so large a sum on the tunnel, the question arises, how shall we use it to derive the greatest good to the whole people? the state now holds, as owner substantially, the troy and greenfield railroad and the tunnel, at a cost of about twelve millions. its value depends wholly upon the future development of business, but its relations are such to other railroad interests, that i have no doubt that, if the state desires to sell the tunnel, notwithstanding its great cost, negotiations could be made to dispose of it at a price that would return to the state the moneys expended, but it would be at the risk of sacrificing the prosperity of its own industrial interests. there are various and conflicting opinions expressed in regard to the business that may be done. some parties who appeared before the committee declared that the completion of the tunnel could only be compared to the removal of a dam, to be followed by a flood of business beyond our power to properly care for; while others were equally confident that the traffic now flowing through other channels would be diverted to the new one only through the influence of time and energetic labor. all, however, agreed in the opinion that, under proper management it was destined to become, at no very distant day, perhaps, the great avenue for trade between the east and west. the eagerness with which various railroad corporations seek its control by "_ways_ and _means_," if honest, should be convincing proof of the great importance of the tunnel to the public, and if not honest, it should merit the condemnation of every honest man in the community. position of the committee. on certain points the committee were unanimous. _first:_ that the state should own and control the tunnel in such manner as to secure to the whole state the ultimate benefit to be derived from its construction, and to secure to all persons and corporations seeking to use it, equal rights. _second:_ that to attain the highest benefit to be derived from this new line, a corporation strong enough to provide sufficient equipment and terminal facilities should be formed, able to command connections with roads outside of the state and to compete with a fair share of success with the existing corporations. how best to attain these ends with a view to cheapness of transportation and efficiency of action the members of the committee differ. the majority reported a bill providing for the consolidation of the boston and lowell railroad company, the fitchburg railroad company, the vermont and massachusetts railroad company, the commonwealth and the troy and boston railroad company into one corporation, with authority to purchase or lease certain other roads, which will make a capital of not less than twenty-five to thirty millions and give control to about five hundred miles of railroad. from this plan the minority have dissented and reported a plan which will place the direct line from boston to troy substantially under one direction, and subject it not to state management but to _state control_. the bill of the majority. to the bill reported by the majority of the committee we have the strongest objections. _first._--it sanctions an enormous inflation of capital. it authorizes a consolidation upon the basis of an appraisal of the value of the several properties to be made by the parties themselves. the railroads of this commonwealth are prohibited by law from making stock dividends, and yet here stock dividends are allowed to such extent as the parties think proper. one of the greatest impositions ever practised upon the public, from which the people of this commonwealth now suffer, is the watered stock of the railroads between albany and chicago. the amount of stock in these roads issued without any equivalent, upon which our traffic is now taxed, is variously estimated at from forty-four millions to one hundred and five millions. the annual tax levied is from three millions to six millions, of which we pay a large share. the majority bill provides for just such a watering of stock, to the extent of perhaps ten millions, according to the appraisal by the parties in interest. we believe this to be all wrong, and should not be sanctioned by the commonwealth. _second._--we utterly dissent from the opinion of the majority in allowing the boston and lowell railroad to come into such a consolidation. the boston and lowell forms no part of the tunnel line. every witness before the committee, except the agents of the corporations themselves, was emphatic against such a consolidation. see governor claflin's testimony, th hearing, page . " j. t. joy " " " " . " c. f. adams, jr., " " " " " " n. c. nash " th " " . " q. a. vinal " th " " . " col. faulkner " " " " . " j. w. brooks " th " " . the northern line has been of very great value to the business of boston and massachusetts; more than any other it has effected that reduction of rates which has returned to boston within the past few years a portion of the export trade. it forms the shortest line at present existing between boston and the lakes, and while lake navigation is open substantially controls the rates over the other lines. mr. nathaniel c. nash says ( th hearing, page ), "we have derived more advantage from that line than from any other source." (see railroad commissioners' report of , page .) while the lowell railroad provided the terminus and the representation in this commonwealth, the other railroads in the line have cooperated in producing this result. it has cheapened food to the people of this commonwealth, and of all new england. the lowell railroad is bound by contracts to continue in this northern line for twenty years to come. although some of the corporations are under financial difficulties, this does not affect the operations of the line. the railroads still exist and must continue to do business, and so far as the advantage of the traffic extends, it matters little who owns or operates the railroads. so impressed are the majority of the committee with the importance of maintaining the northern line that they impose upon the lowell railroad company, as they say, the conditions of withdrawing from the northern line, and make provision for transfer of the business to another line--the boston and maine. they propose to do this in a manner which seems to us weak and futile. the majority bill provides for repeal of the charter of the great northern railroad company, passed in , which authorized the boston and lowell railroad company to consolidate with certain companies in new hampshire, with authority to lease or purchase other railroads leading to ogdensburg and other points in the north and west, and lines of boats on the lakes. as all the other companies in this consolidated line are in new hampshire this charter was ineffective without the cooperation of new hampshire, and to this bill new hampshire has never assented--not from any hostility to through lines, but because it contained objectionable features, such as the consolidation of competing lines, the creation of a monstrous corporation with power to combine in one gigantic monopoly all the railroads within her borders. this charter is mere waste paper, and its repeal would have no more effect than the burning of waste paper. the lowell railroad remains bound by contracts to the northern line, and the majority bill effectually places the northern and tunnel lines under one control. the proposal to transfer the northern line and northern business to the boston and maine railroad seems to us an absurdity. the boston and maine is practically an eastern line; of its whole length, one hundred and twelve miles, only twenty-six could be used in connection with the northern line. it never could or would give that exclusive attention to the business necessary to make such a line successful. its only means of connection is over the manchester and lawrence railroad, the grades of which are too heavy for a successful freight business with the west. the boston and lowell railroad is the natural terminus of this northern line, and no legislation can remove it from this position. moreover the majority bill, placing the boston and lowell railroad and the fitchburg in the same control, and authorizing a lease of the cheshire, gives the consolidated company such a substantial control of the whole northern business that its transfer to the boston and maine would necessarily be followed by such disastrous competition as to preclude such a connection. it must inevitably result in a consolidation of the tunnel and the northern line under one management. in creating a new line we destroy one which already exists. our true policy is to maintain unimpaired our four routes to the west, and under whatever management they may be, at all events maintain that they shall be independent of each other. if a consolidation is to be made of the tunnel line we are clearly of the opinion that it should be of the direct line only between boston and troy, including the fitchburg, vermont and massachusetts, troy and greenfield, and troy and boston, and the massachusetts central if it desires to form part of such a line. the boston and lowell railroad, and nashua railroad should be studiously kept apart from such a line, because it forms no natural part, and does form a natural part of another line. it is urged that the possession of terminal facilities in boston should be allowed a controlling influence in this matter; that the boston and lowell railroad has obtained the only convenient terminus in boston for a great western line--more than is needed for its own business, or the business of the northern line, and therefore that the railroad policy of the commonwealth should be compelled to yield to its position. to this there are two answers. _first._--that these facilities were obtained for the northern line, and by urgent representations of its necessities, and if they are not needed for that business they should be transferred to other corporations that do need them. the commonwealth has full power in the case, and it is only necessary to invoke the same power which the majority bill gives the consolidation company to take property from the fitchburg, to take from the lowell railroad company the property which it now represents as not needed for its business which it has obtained under the representation of a public necessity. _secondly._--the question of terminal facilities is too unimportant in itself to be permitted to determine in the least degree the decision of a great state policy; other facilities can be obtained as good as the lowell. _finally._--we object to the plan of the majority because it continues the policy of placing our last remaining line to the west under the control and management of a stock corporation. it cannot be denied that there is great and wide-spread dissatisfaction with our present railroad system, and its management. we have tried in vain to control by special legislation, and it may well be acknowledged that the trial has not been very successful. regulation by special legislation. no system has ever been devised better calculated to introduce corruption into our state government than the present method of regulating railroads by special laws. every senator knows what influences are brought to bear to promote and defeat the various projects of special legislation. no! mr. president, i have over-stated--i am sure that no senator at this board does know _all_ the "ways and means" that are used to influence members to secure votes for the passage of various bills in the interest of railroads. every senator is aware how powerful and wide-spread is the pressure when public railroad legislation is under consideration. if these influences were confined to the questions of special or general railroad legislation, great as the evil is, it would not be irreparable. but unhappily the evil does not stop here. hardly a question of special or general legislation is decided by either branch of the legislature without being affected in a greater or less degree by these railroad questions. it prolongs our sessions and fills our lobbies with the advocates of private corporations, and these special guardians of the rights of the people in the service and pay of railroad corporations astonish the members from the rural districts by their disinterestedness in their "labors of love" and benevolence--making their stay at the capital so pleasant and agreeable without money, but not without price--as to create a strong desire to serve the "dear people" another term, and obligations are exchanged that demand the presence and service of these men. no i not men alone, but men and women at our town caucuses and conventions, that favors granted may be reciprocated in securing the nomination, and thereby the election of the men who are willing to be run by rail road interests. if this state of things does not corrupt legislators, it is because legislators are incorruptible. we know its results in other states, and we may well fear it here. special legislation has totally failed in securing the results intended, and left behind a train of unmitigated evils which must increase with the increased magnitude of the railroad interest, and the growth of railroad corporations. the establishment of such a corporation as is provided for in the majority bill may well be dreaded. the creature will be more powerful than its creator. control of the tunnel. the committee were clear and unanimous in the opinion that the state should under no circumstances part with the absolute control of the tunnel to a private corporation. the majority bill is the first step in giving up the control of the tunnel to a private corporation. it gives to that corporation control of the whole line, except the tunnel; and entrusts it with the operators of the tunnel itself. the pressure upon the state to part with the tunnel will grow with the increase of business; the whole power and usefulness of the line must rest in the hands of the corporation which owns the railroad entering the tunnel on either side. i am not old in railroad tactics--but, mr. president--with the bill reported by the majority of the committee, i think i should have no difficulty--with less than one-half of the amount of the money expended in the efforts to pass the bill--to capture the tunnel from the state in three years, and it would be accomplished in such a manner through the representatives of the people, that no one would presume to question my honesty. the commonwealth, owning the tunnel,--the most valuable portion of the line, the _key_ to the whole line,--has no voice in its management except a minority in the board of direction; no voice in fixing rates, no influence in its operations. this is all placed in the hands of a private corporation, governed by stockholders, whose stock is at all times in the market, and may be purchased at any time by any parties who deem it for their interest to control the line. the corporation may at any time combine with existing corporations to fix rates, and thus the main object sought by the state in constructing the tunnel--an independent and competing line--be defeated. the purposes of the minority. the minority of the committee in the plan which they propose to the legislature, have had two purposes in view. _first:_ absolute and perpetual control of the tunnel, built with the public money for the benefit of the people of the whole commonwealth; and _second:_ _state control_ of the tunnel line. i use the words _state control_ designedly, as distinguished from state ownership, or state management. state ownership of a railroad without state management is useless. state management may sink into political management which might be disastrous to the public, and to the railroad. but state control is a very different thing; precisely what legislatures have sought in vain to attain. we have endeavored to give it by special legislation, but all in vain; and yet just this is what we want. the idea is too firmly fixed in the public mind to be eradicated without a fair and conclusive trial, that fares and freights are now too high--that cheap transportation _is_ necessary, and can be furnished without interfering with a fair return for the capital invested. you cannot expect private corporations whose whole object is to make money for stockholders, to try this experiment fairly, and ascertain how cheaply transportation can be afforded. railroad corporations do sometimes compete, but the sole object and purpose of such competition is eventual combination, and in that combination, the public must suffer. we want to establish a corporation which shall compete to increase its business without any ulterior view of combination to raise rates, and such a corporation is found under the plan presented by the minority of the committee. the minority bill. this bill proposes first that the troy and greenfield railroad and tunnel shall remain the property of the state. _second._ that the state shall obtain by lease the control of the railroads forming the direct tunnel line. we have reason to believe that this can be effected. we have assurances that the fitchburg railroad company will assent to the terms of this bill. if the only result of this bill is to secure the control of the fitchburg railroad it will be worth the trial. the fitchburg railroad with its connection with the tunnel, has a commanding position with reference to the railroads of the state. what we want to secure is a free system of competition, without the power of combination, which is now the bane of our railroad system, in the hands of private corporations. rates are now fixed to a remarkable extent by combination, and not by competition. every business man knows that the freight rates between important points are fixed at meetings of freight agents, who consider not what is a fair price for rendering the service, but what will best pay the corporations which control the business. the great need of the business community of boston and massachusetts, is a line to the west, making the nearest connection with the lakes, which will do the business at fair and uniform rates, and which shall be managed in the interest of the public, and not of stockholders. such a line can be secured under the provisions of the minority bill, which will establish a through line with power to connect with lake navigation at oswego, on lake ontario, and be substantially under state control. the necessity of extending the line to oswego, to some point on the lake is obvious, because every other railroad communicating with the west, except the great northern route, is now under the control of new york. at any lake port navigation is open for seven or eight months in the year, and gives a direct communication with the great centres of western commerce. the tunnel line ending at troy can give little advantage over the present western line--the boston and albany railroad. the effect of state control of the tunnel line. one great purpose of controlling one important line, is the effect upon other lines. our system of railroads is so interwoven that all our railroads are to some extent competing, and the operation of one railroad by a corporation in the interest of the public will to a great extent control the whole railroad system of the state. the direct tunnel line probably now occupies the most important controlling position of any in the state. it can be made a regulator of the western business of the state. it can by its connections with the cheshire and other vermont and massachusetts railroads, largely control the northern lines. it will, by its many connections, bring the whole state in direct connection with the north and west. the great success of the so-called belgium system is founded on this principle,--the control of the whole by the direct operation of a small portion. the position of our massachusetts railroads is, in this respect, not unlike that of belgium. our railroads are so closely connected together that the state control of one road will be felt throughout the whole system. the popular feeling in favor of state control. it cannot be denied that the popular feeling has been steadily growing in favor of state operation of railroads in spite of all that has been said of the danger of corruption and of the inefficiency of state management. the people, confident in their own integrity and their own power, have not indistinctly shown their desire to fairly try the experiment, and the circumstances are more favorable for such an experiment than will probably again occur. the state now owns the important part of the line,--that part which is necessary to change the line from a disconnected local line of railroads to a great through line. it has been built at great cost. its opening gives great value to the connecting roads. if it was worth the cost of construction, this value can only be shown by a development of business which will require a series of years, and will be attended with corresponding advantages to all connecting roads. this development of business can hardly be expected without substantially giving up the control of the tunnel to the line which operates it. the majority bill does give such a control. we deem it the best way for the state retaining the tunnel to obtain upon fair terms the control of the connecting roads, and fairly try the experiment of operating a railroad to ascertain how cheaply transportation can be furnished, and yet return a fair remuneration for the capital employed. the public demands such an experiment to be tried, and a better opportunity to try can never exist. safety of the experiment. of this there can be no reasonable doubt, for a corporation formed under the provisions of the minority bill possesses all the advantages that can be obtained by consolidation under one private corporation, as authorized by the majority bill, and the additional advantages of state and corporate management combined, which would be efficient and reliable, beyond that of ordinary railroad corporations, inasmuch as their acts would be most carefully watched and criticised by others than stockholders, and the honor of securing a successful result to so great an experiment and enterprise in the interests of the people, would be a far greater incentive to even political ambition, than the compensation received; for "great deeds foreshadow great men," and the people are not slow in their rewards to those who are honest and earnest in their service. why, mr. president, if i had the ability to manage this enterprise, i should hold the _honor_ of making this enterprise in the interest of the state a success of more importance than the honor of being the governor of massachusetts. and when a man's reputation is thus at stake, he cannot afford to cheat himself by withholding from the state his best talents and energies. it has another and still greater advantage,--the endorsement of the commonwealth of massachusetts, which furnishes power and capital for terminal facilities, equipment and the improvement of the line at a cheaper rate than any consolidated company can procure it; and cheap capital in disinterested hands secures _cheap_ transportation. can there be any doubt that a corporation thus formed and managed will prove a financial success? if not a success, then we have great reason to distrust a private corporation; with far less advantages, and a larger capital, for doing the same business must prove a financial failure. to demonstrate this point in a more practical manner, we will assume a proposition and verify this proposition by figures. judging from the present local business now done on the several roads--forming what is anticipated as the tunnel line, and the testimony of eminent railroad men of the business that is sure to come to this great through route to the west--it is fair to assume that the whole will do a business that will average six millions a year for the first five years; twenty-five per cent. of the gross earnings of the leased roads, and property are reserved to provide for settlement of the conditions of the said leases; and as they are not guaranteed the payment of any amount beyond what their present business pays, can there be any doubt but what the twenty-five per cent. on the increased business will pay the six per cent. interest on the capital loaned to increase the facilities for extending the business over the line? the railroad commissioners report that the average expenses of all the railroads of the commonwealth is seventy-five per cent. of their gross earnings; but there is no doubt but what it can be proved that it cost less than seventy per cent. on the great trunk lines, and one of the oldest and most successful railroad managers assured me that this tunnel line could be run for sixty per cent., but we will call it seventy per cent., which makes with the twenty-five per cent. ninety-five per cent., leaving five per cent. for net profit on the whole business of six millions, which is $ , . what next? we have for the credit of the corporation or state, twenty-five per cent. of the gross earnings of the business done on the troy and greenfield railroad and through the tunnel. calling the tunnel twenty-three miles in length,--which it is conceded it should be called for what it saves in distance and grades,--and with the troy and greenfield railroad, which is forty-four miles, we have one-third of the whole distance, and it is the judgment of practical railroad men that out of the six millions of business, two millions would pass over this division and through the tunnel; and twenty-five per cent. on two millions is $ , income, which, added to the $ , , gives a net income of $ , to the state, which is nearly six per cent. on thirteen and one-half millions, the cost of the tunnel and troy and greenfield railroad, with an additional expenditure of one and one-half millions needed to make this division of the route what it should be as a part of the great through line. in proportion as the business increases, in that same proportion will the profits increase, and when the business shall amount to ten millions, which i have no doubt it will in less than ten years, you create a fund over and above the interest on the whole cost that can be used for extinguishing the debt, purchasing the stock of the leased roads, as the value is fixed by the terms of the lease, or for the reduction of rates of fares and freights. if this proposition will not bear investigation, pray tell me how the stockholders of the consolidated corporations are to receive dividends on their watered stock, with increased cost of improvements of the line, and equipment for doing the same business. the alleged danger of political corruption. a chief argument against the system proposed is the danger of political corruption likely to follow the employment of a large number of men in public business. _second._--it is alleged that the public management of any great public service is less efficient than private management. the purpose of the minority of the committee in proposing their plan, was to provide a corporate body removed as far as possible from political influence. the state trustees are appointed by the governor and council. they are appointed for _five_ years. a single vacancy occurs each year. they hold nearly the same position in regard to the operatives employed ill the operation of the corporation, as directors of corporations, and no one ever heard of directors exerting any great political influence, particularly state directors. i doubt if any director of any railroad corporation in the state ever knew or thought to influence the political vote of an operative. if they choose, the managers of any private corporation could exert a greater and more injurious political influence than these state trustees. if the power is dangerous in state trustees, who must be selected by your governor, it is far more dangerous in the hands of persons elected by stockholders of a private, money-making corporation, whose interests are in direct antagonism to the interests of the public. this argument applies to corporate management only with a much greater force. let corporate management be unmasked and it would make state management hide its face with shame. (see extract new york state committee on erie.) "if the principle is to be established that a few interested parties of stock-jobbers, having no permanent interest, can, by the corrupt use of money or by violence, take and hold possession of a great railroad corporation, and reimburse themselves out of its treasury, it is time the matter was understood by the public. as to the payment of money to influence legislation connected with said company, or other irregularities, the testimony was enough to show that the railroad companies have been in the habit of expending large sums from year to year, either to secure or defeat the passage of bills. it appears conclusive that a large amount, reported by one witness at $ , , was appropriated for legislative purposes by the railroad interest in , and that $ , was the erie's portion. in this connection the committee denounce the lobby roundly. it is further in evidence that it has been the custom of the managers of the erie railroad from year to year in the past to expend large sums to control elections and to influence legislation. in more than one million dollars was disbursed from the treasury for 'extra and legal services.' what the erie has done, other great corporations are doubtless doing from year to year. we have here simply an acknowledgment, of the fact. combined as they are, the power of the great moneyed corporations of this country are a standing menace to the liberties of the people. the railroad lobby flaunts its ill-gotten gains in the faces of our legislators, and in all our politics the debasing effect of its influence is felt." this cry of political corruption against state management is but the resurrection of the old party ghost which has always been retained in the service of all political parties to frighten people that are naturally timid and conservative; and this terrible spectre has often been the means of delaying and defeating enterprises that were for the best interests of the people. i remember, mr. president, when this ghost was exhibited by the democratic party in every town in this state; and the people were made to believe that the loan made by the state to the boston and albany (western) railroad would ruin the state; that every man's farm was mortgaged at nine dollars per acre; and men believed it, for that was in times when the people followed party leaders through faith; when it was said that the true test of the political faith of a new hampshire democrat was to wake him up with the inquiry, "who made you?" and if he answered promptly, "isaac hill, sir," he was to be trusted as one of the faithful. the effect of this great outcry was to destroy confidence in the enterprise and the stock at one time could not be _given_ away for fear of assessments. and if the people at that time could have been guaranteed that the loss of the state should not exceed the four million loaned, they would have gladly given another million as a guarantee. but they could not rid themselves of the supposed burden, and the result has been the development of a great enterprise in the interests of the state in spite of their fears. this was in a measure to the credit of state management. as to the efficiency of the plan, it remains to be tried; but in the language of the minority report we believe such a management would be efficient and reliable beyond that of ordinary railroad corporations. it combines state control with corporate management. the governor and council could be depended upon to appoint suitable persons as trustees. the railroad corporations would naturally appoint their most efficient agents as trustees. such a board could find no difficulty in securing the services of the ablest railroad officers to direct and aid in the management. as the plan has no precedent it cannot be judged from the record, and the prejudice existing against state management cannot fairly apply to this plan; but if it could have a fair trial we have no doubt of its efficiency and success; and we are not alone in this opinion, for this plan has received the full endorsement of eminent railroad managers, successful and prominent manufacturers and merchants, and the chairman of the railroad commissioners, together with many of our most enterprising and conservative citizens. state pensioners. it is urged that the plan proposed creates a large class of state pensioners to whom the revenues of the treasury are pledged. they are state pensioners in the same sense as any individual who leases property to the state for a fixed rent, is a state pensioner. every railroad charter contains a provision for the acquisition of the corporate property by the state, by payment of its presumed value. as well say that all these charters are pension bills. the minority bill simply provides that stockholders yielding their property to the state, shall have a remuneration for the property surrendered. it makes little difference to the individual whether his compensation comes in the form of the payment of a fixed sum or of an annual annuity. it does make some difference to the state, whether it increases a debt to payoff these stockholders at once, or pays such interest as the property acquired may be fairly presumed to earn. the guarantee does not exceed the dividends which the property may be expected to earn, and the advantage which a lease gives over a purchase by avoiding the transfer and changing of capital should not be overlooked. in a word, these stockholders are pensioners only in the sense that they become entitled to secure annuities from the state for which they pay beforehand a full equivalent into the treasury. the benefits of the proposed plan. it makes absolutely certain the perpetual control of the tunnel for the benefit of the people of the whole state. it secures to the people by whose money it has been built, the ultimate value of the enterprise, whatever that value may prove to be. it secures to the people an independent western line, to be managed for the benefit of the people, free from any danger of combinations by which rates are fixed. it secures to all corporations desiring to use the tunnel, equal rights. it secures a line stronger than any other, amply able to provide equipment and facilities, and to compete with powerful corporations in neighboring states. it fixes the capital of the corporation without danger of inflation, and without risk of speculative control. it enables the people to try fairly the experiment of cheap transportation. it provides equally with the plan of the majority for the interchange of depots, by which the crossings at the north side of the city may be avoided. if only one-half of these advantages can be gained the experiment is worth trying. if it succeeds and our expectations are fully realized, it will confer upon the people the greatest boon since the introduction of railroads. senators will bear me witness that i have never solicited their vote on any personal consideration, and in the decision of this great question, i can only appeal to you as legislators to record your votes in accordance with your convictions of duty to the people of this commonwealth, and for the protection of her six hundred millions of industrial interests; unbiased by any local or personal interest, keeping in mind that there is no power but that of the state that is safe to trust in the great exigency that now exists. * * * * * transcriber's notes: all obvious typos were corrected. hyphenation was standardized. the placement of quotation marks were not standardized; but left as in the original printed version. [transcribers' notes: some tables don't sum to the numbers indicated; no corrections have been made. all numbers are from the original. minor inconsistencies in hyphenation have been retained. subscripts are represented by underscore and curly braces e.g., co_{ }. italics are represented by underscores before and after e.g., _italics_. bold is represented by equal signs before and after e.g., =bold=. small caps have been replaced with all caps.] american society of civil engineers instituted transactions paper no. the new york tunnel extension of the pennsylvania railroad. the north river tunnels.[a] by b. h. m. hewett and w. l. brown, members, am. soc. c. e. [a] presented at the meeting of june st, . introduction. the section of the pennsylvania railroad tunnel work described in this paper is that lying between tenth avenue, new york city, and the large shaft built by the company at weehawken, n. j., and thus comprises the crossing of the north or hudson river, the barrier which has stood for such a long time between the railroads and their possession of terminal stations in new york city. the general plan and section, plate xxviii, shows the work included. this paper is written from the point of view of those engaged by the chief engineer of the railroad company to look after the work of construction in the field. the history of the undertaking is not included, the various phases through which many of the designs and plans passed are not followed, nor are the considerations regarding foundations under the subaqueous portions of the tunnels and the various tests made in connection with this subject set out, as all these matters will be found in other papers on these tunnels. this paper only aims to describe, as briefly as possible, the actual designs which were finally adopted, the actual conditions met on the ground, and the methods of construction adopted by the contractors. for easy reference, and to keep the descriptions of work of a similar character together, the subject will be treated under the four main headings, viz.: shafts, plant, land tunnels, and river tunnels. shafts. it is not intended to give much length to the description of the shafts or the land tunnels, as more interest will probably center in the river tunnels. the shafts did not form part of the regular tunnel contract, but were built under contract by the united engineering and contracting company while the contract plans for the tunnel were being prepared. in this way, when the tunnel contracts were let, the contractor found the shafts ready, and he could get at his work at once. two shafts were provided, one on the new york side and one on the new jersey side. their exact situation is shown on plate xxviii. they were placed as near as possible to the point at which the disappearance of the rock from the tunnels made it necessary to start the shield-driven portion of the work. the details of the shafts will now be described briefly. _the manhattan shaft._--the manhattan shaft is located about ft. north of the tunnel center; there was nothing noticeable about its construction. general figures relating to both shafts are given in table . _the weehawken shaft._--the weehawken shaft is shown in fig. . this, as will be seen from table , was a comparatively large piece of work. the shaft is over the tunnels, and includes both of them. in the original design the wall of the shaft was intended to follow in plan the property line shown in fig. , and merely to extend down to the surface of the rock, which, as disclosed by the preliminary borings, was here about ft. below the surface. however, as the excavation proceeded, it was found that this plan would not do, as the depth to the rock surface varied greatly, and was often much lower than expected; the rock itself, moreover, was very treacherous, the cause being that the line of junction between the triassic sandstone, which is here the country rock, and the intrusive trap of the bergen hill ridge, occurs about one-third of the length of the shaft from its western end, causing more or less disintegration of both kinds of rock. therefore it was decided to line the shaft with concrete throughout its entire depth, the shape being changed to a rectangular plan, as shown in the drawings. at the same time that the shaft was excavated, a length of ft. of tunnels at each end of it was taken out, also on account of the treacherous nature of the ground, thus avoiding risk of injury to the shaft when the tunnel contractors commenced work. there was much trouble with floods during the fall of , and numerous heavy falls of ground occurred, in spite of extreme care and much heavy timbering. the greatest care was also taken in placing the concrete lining, and the framing to support the forms was carefully designed and of heavy construction; the forms were of first-class workmanship, and great care was taken to keep them true to line. a smooth surface was given to the concrete by placing a -in. layer of mortar at the front of the walls and tamping this dry facing mixture well down with the rest of the concrete. the east and west walls act as retaining walls, while those on the north and south are facing walls, and are tied to the rock with steel rods embedded and grouted into the rock and into the concrete. ample drainage for water at the back of the wall was provided by upright, open-joint, vitrified drains at frequent intervals, with dry-laid stone drains leading to them from all wet spots in the ground. a general view of the finished work is shown in fig. , plate xxix, and table gives the most important dates and figures relating to this shaft. table .--particulars of shafts on the north river tunnels of the pennsylvania railroad tunnels into new york city. +===========+=====+======+======+==========+========+===========+========+ |location. |depth| width|length|excavation|concrete| date| date| | | in| in| in|(including|in cubic|commenced.|finished.| | |feet.| feet.| feet.| drifts),| yards.| | | | | | | | in cubic| | | | | | | | | yards. | | | | +-----------+-----+------+------+----------+--------+----------+---------+ |manhattan: | | | | , | |june th,| december| | th avenue| | | | | | .| th,| |and d | | | | | | | .| |street. | | | | | | | | | | | | | | | | | |weehawken: | | at| at| , | , |june th,|september| |baldwin | |bottom|bottom| | | .| st, | |avenue. | | , at| . | | | | . | | | | top|at top| | | | | | | | .| .| | | | | |===========+=====+======+======+==========+========+==========+=========+ +==========+====================+=============+============+===========+ |location. |ground met: |lined with: | cost to | cost per | | | | | railroad |cubic foot.| | | | | company. | | +----------+--------------------+-------------+------------+-----------+ |manhattan:|top ft. filled; |concrete | $ , . | $ . | | th |red mica schist and |reinforced | | | |avenue and|granite. |with steel | | | | d | |beams down to| | | |street. | |rock. | | | | | | | | | |weehawken:|top ft. filled, |concrete with| , , | . | |baldwin |ft. sand and |steel | | | |avenue. |hardpan, decomposed |tie-rods in | | | | |rock (trap and |rock. | | | | |sandstone) below. | | | | +==========+====================+=============+============+===========+ [illustration: final design of weehawken shaft plan longitudinal section transverse section fig. .] after the tunnel work was finished, both shafts were provided with stairs leading to the surface, a protective head-house was placed over the new york shaft, and a reinforced concrete fence, ft. high, was built around the weehawken shaft on the company's property line, that is, following the outline of the shaft as originally designed. plant. working sites. before beginning a description of the tunnel work, it may be well to set out in some detail the arrangements made on the surface for conducting the work underground. all the work was carried on from two shafts, one at eleventh avenue and d street, new york city--called the manhattan shaft--and one at baldwin avenue, weehawken, n. j.--called the weehawken shaft. [illustration: weehawken shaft. excavation fig. .] the characteristics of the two sites were radically different, and called for different methods of handling the transportation problem. the shaft site at manhattan is shown on plate xxx. it will be seen that there was not much room, in fact, the site was too cramped for comfort; the total area, including the space occupied by the old foundry, used for power-houses, offices, etc., was about , sq. yd. this made it necessary to have two stages, one on the ground level for handling materials into the yard, and an overhead gantry on which the excavated materials were handled off the premises. the yard at weehawken was much larger; it is also shown on plate xxx. its area was about , sq. yd. in the yard proper, and there was an additional space of about sq. yd. alongside the wharf at the "north slip," on the river front, connected with the main portion of the yard by an overhead trestle. all the cars at manhattan were moved by hand, but at weehawken two electric locomotives with overhead transmission were used. power-house plant. at the manhattan shaft the power-house plant was installed on the ground floor of the old foundry building which occupied the north side of the leased area. this was a brick building, quite old, and in rather a tumble-down condition when the company took possession, and in consequence it required quite a good deal of repair and strengthening work. the first floor of the building was used by the contractor as offices, men's quarters, doctor's offices, and so on, and on the next one above, which was the top floor, were the offices occupied by the railroad company's field engineering staff. on the weehawken side, the plant was housed in a wooden-frame, single-story structure, covered with corrugated iron. it was rectangular in plan, measuring by ft. at both sides of the river the engines were bedded on solid concrete on a rock foundation. the installation of the plant on the manhattan side occupied from may, , to april, , and on the weehawken side from september, , to april, . air pressure was on the tunnels at the new york side on june th, , and on the weehawken side on the th of the same month. [illustration: plate xxix. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. . fig. .] the plants contained in the two power-houses were almost identical, there being only slight differences in the details of arrangement due to local conditions. a list of the main items of the plant at one power-house is shown in table . table .--plant at one power-house. +======+======================================================+========+ |no. of| | | |items.|description of item. | cost.| |------+------------------------------------------------------+--------| |three | -h.p. water-tube sterling boilers | $ , | |two |feed pumps, george f. blake manufacturing company | | |one |henry r. worthington surface condenser | , | |two |electrically-driven circulating pumps on river front | , | |three |low-pressure compressors, ingersoll-sergeant drill | , | | |company | | |one |high-pressure compressor, ingersoll-sergeant drill | , | | |company | | |three |hydraulic power pumps, george f. blake manufacturing | , | | |company | | |two |general electric company's generators coupled to ball | , | | |and wood engines | | |------+------------------------------------------------------+--------| | |total cost of main items of plant | $ , | |------+------------------------------------------------------+--------| | summary of cost of one plant. |-------------------------------------------------------------+--------+ |total cost of main items of plant | $ , | | | | |cost of four shields (including installation, demolition, | , | |large additions and renewals, piping, pumps, etc.) | | | | | |cost of piping, connections, drills, derricks, installation | , | |of offices and all miscellaneous plant | | | | | |cost of installation, including preparation of site | , | |-------------------------------------------------------------+--------| |total prime cost of one power-house plant |$ , | |=============================================================+========| the following is a short description of each item of plant in table : _boilers._--at each shaft there were three -h.p., water-tube boilers, class f (made by sterling and company, chicago, ill.). they had independent steel stacks, in. in diameter and ft. above grate level; each had , sq. ft. of heating surface and sq. ft. of grate area. the firing was by hand, and there were shaking grates and four doors to each furnace. under normal conditions of work, two boilers at each plant were able to supply all the steam required. the average working pressure of the steam was lb. per sq. in. the steam piping system was on the loop or by-pass plan. the diameter of the pipes varied from in. in the main header to in. in the body of the loop. the diameter of the exhaust steam main increased from in. at the remote machines to in., and then to in., at the steam separator, which in turn was connected with the condensers. a pipe with an automatic relief valve from the exhaust to the atmosphere was used when the condensers were shut down. all piping was of the standard, flanged extra-heavy type, with bronze-seated gate-valves on the principal lines, and globe-valves on some of the auxiliary ones. there was an -in. water leg on the main header fitted with a mason-kelly trap, and other smaller water traps were set at suitable intervals. each boiler was fitted with safety valves, and there were automatic release valves on the high-and low-pressure cylinders of each compressor, as well as on each air receiver. buckwheat coal was used, and was delivered to the bins on the manhattan side by teams and on the weehawken side by railroad cars or in barges, whence it was taken to the power-house by -ft. gauge cars. an average of tons of coal in each hours was used by each plant. the water was taken directly from the public service supply main. the daily quantity used was approximately , gal. for boiler purposes and , gal. for general plant use. wooden overhead tanks having a capacity of , gal. at each plant served as a -hour emergency supply. _feed pumps._--there were two feed pumps at each plant. they had a capacity of cu. ft. per min., free discharge. the plungers were double, of -in. diameter, and -in. stroke, the steam cylinders were of -in. diameter and -in. stroke. an injector of the "metropolitan double-tube" type, with a capacity of cu. ft. per min., was fitted to each boiler for use in emergencies. the feed-water heater was a "no. cochrane," guaranteed to heat , lb. of water per hour, and had a total capacity of . cu. ft. it was heated by the exhaust steam from the non-condensing auxiliary plant. _condenser plant._--there were two surface condensers at each plant. each had a cooling surface sufficient to condense , lb. of steam per hour, with water at a temperature of ° fahr. and barometer at in., maintaining a vacuum of in. in the condenser. each was fitted with a blake, horizontal, direct-acting, vacuum pump. _circulating-water pumps._--two circulating-water pumps, supplying salt water directly from the hudson river, were placed on the wharf. they were -in. centrifugal pumps, each driven by a -h.p., general electric company's direct-current motor ( volts and rev. per min.), the current being supplied from the contractor's power-house generators. the pumps were run alternately hours each at a time. those on the manhattan side were , ft. from the power-house, and delivered their water through a -in. pipe; those on the weehawken side were ft. away, and delivered through a -in. pipe. there was also a direct connection with the city mains, in case of an accident to the salt-water pumps. _low-pressure compressors._--at each plant there were three low-pressure compressors. these were for the supply of compressed air to the working chambers of the subaqueous shield-driven tunnels. they were also used on occasions to supply compressed air to the cylinders of the high-pressure compressors, thus largely increasing the capacity of the latter when hard pressed by an unusual call on account of heavy drilling work in the rock tunnels. they were of a new design, of duplex corliss type, having cross-compound steam cylinders, designed to operate condensing, but capable of working non-condensing; the air cylinders were simple duplex. the steam cylinder valves were of the corliss release type, with vacuum dash-pots. the valves in the air cylinders were mechanically-operated piston valves, with end inlet and discharge. the engines used steam at lb. pressure. the high-and low-pressure steam cylinders were in. and in. in diameter, respectively, with a stroke of in. and a maximum speed of rev. per min. the two air cylinders were ½ in. in diameter, and had a combined capacity of . cu. ft. of free air per revolution, and, when running at rev. per min., each machine had an actual capacity of , cu. ft. of free air per min., or , cu. ft. per hour. the air cylinders were covered by water-jackets through which salt water from the circulating pumps flowed. a gauge pressure of lb. of air could be obtained. each compressor was fitted with an automatic speed and air-pressure regulator, designed to vary the cut-off according to the volume of air required, and was provided with an after-cooler fitted with tinned-brass tube and eight tobin-bronze tube-plates having sq. ft. of cooling surface; each one was capable of reducing the temperature of the air delivered by it to within ° fahr. of the temperature of the cooling water when its compressor was operated at its fullest capacity. from the after-cooler the air passed into a vertical receiver, ft. in. in diameter and ft. high, there being one such receiver for each compressor. the receivers were tested to a pressure of lb. per sq. in. the after-coolers were provided with traps to collect precipitated moisture and oil. the coolers and receivers were fitted with safety valves set to blow off at lb. above the working pressure. the air supply was taken from without, and above the power-house roof, but in very cold weather it could be taken from within doors. _high-pressure compressors._--there was one high-pressure compressor at each plant. each consisted of two duplex air cylinders fitted to a cross-compound, corliss-bass, steam engine. the two steam cylinders were and in. in diameter, respectively, and the air cylinders were ¼ in. in diameter and had a -in. stroke. the air cylinder was water-jacketed with salt water supplied from the circulating water pumps. the capacity was about , cu. ft. of free air per min. when running at rev. per min. and using intake air at normal pressure, but, when receiving air from the low-pressure compressors at a pressure of lb. per sq. in., the capacity was , cu. ft. of free air per min.; receiving air at lb. per sq. in., the capacity would have been , cu. ft. of free air per min. this latter arrangement, however, called for more air than the low-pressure compressors could deliver. with the low-pressure compressor running at rev. per min. (its maximum speed), it could furnish enough air at . lb. per sq. in. to supply the high-pressure compressor running at rev. per min. (its maximum speed); and, with the high-pressure compressor delivering compressed air at lb., the combined capacity of the arrangement would have been , cu. ft. of free air per min. the air passed through a receiver, ft. in. in diameter and ft. high, tested under a water pressure of lb. per sq. in., before being sent through the distributing pipes. _hydraulic power pumps._--at each power-house there were three hydraulic power pumps to operate the tunneling shields. one pump was used for each tunnel, leaving the third as a stand-by. the duplex steam cylinders were in. in diameter, with a -in. stroke; the duplex water rams were - / in. in diameter with a -in. stroke. the pumps were designed to work up to , lb. per sq. in., but the usual working pressure was about , lb. the piping, which was extra heavy hydraulic, was connected by heavy cast-steel screw couplings having a hexagonal cross-section in the middle to enable tightening to be done with a bolt wrench. the piping was designed to withstand a pressure of , lb. per sq. in. _electric generators._--at each plant there were two electric generators supplying direct current for both lighting and power, at volts, through a two-wire system of mains. they were of type m-p, class , kw., amperes, rev. per min., volts no load and volts full load. they were connected direct to by by -in., center-crank, tandem-compound, engines of h.p. at rev. per min. a switch-board, with all the necessary fuses, switches, and meters, was provided at each plant. _lubrication._--in the lubricating system three distinct systems were used, each requiring its own special grade of oil. the journals and bearings were lubricated with ordinary engine oil by a gravity system; the oil after use passed through a "white star" filter, and was pumped into a tank about ft. above the engine-room floor. the low-pressure air cylinders were lubricated with "high test" oil, having a flash point of ° fahr. the oil was forced from a receiving tank into an elevated tank by high-pressure air. when the tank was full the high-pressure air was turned off and the low-pressure air was turned on, in this way the air pressure in the oil tank equalled that in the air cylinder being lubricated, thus allowing a perfect gravity system to exist. the steam cylinders and the high-pressure air cylinders were fed with oil from hand-fed automatic lubricators made by the detroit lubrication company, detroit, mich. "steam cylinder" oil was used for the steam cylinders and "high test" oil (the same as used for the low-pressure air cylinders) for the high-pressure air cylinders. the air cylinder and steam cylinder lubricators were of the same kind, except that no condensers were necessary. the steam cylinder and engine oil was caught on drip pans, and, after being filtered, was used again as engine oil in the bearings. the oil from the air cylinders was not saved, nor was that from the steam cylinders caught at the separator. _cost of operating the power-house plants._--in order to give an idea of the general cost of running these plants, tables and are given as typical of the force employed and the general supplies needed for a -hour run of one plant. table gives a typical run during the period of driving the shields, and table is typical of the period of concrete construction. in the latter case the tunnels were under normal air pressure. before the junction of the shields, both plants were running continuously; after the junction, but while the tunnels were still under compressed air, only one power-house plant was operated. table .--cost of operating one power-house for hours during excavation and metal lining. ===+===================+====================+============= no.| labor. | rate per day. | amount. ---+-------------------+--------------------+------------- |engineers | $ . | $ . |firemen | . | . |oilers | . | . |laborers | . | . |pumpmen | . | . |electricians | . | . |helper | . | . ---+-------------------+--------------------+------------- total per day | $ . --------------------------------------------+------------- total for days | $ , . --------------------------------------------+------------- supplies. -----------------------+--------------------+------------- coal ( tons per day) | $ . | $ . water | . | . oil ( gal. per day) | . | . waste ( lb. per day) | . | . other supplies | . | . -----------------------+--------------------+------------- total per day | $ . --------------------------------------------+------------- total for days | $ , . --------------------------------------------+------------- total cost of labor and supplies for days| $ , . ============================================+============= _stone-crusher plant._--a short description of the stone-crusher plant will be given, as it played an important part in the economy of the concrete work. in order to provide crushed stone for the concrete, the contractor bought (from the contractor who built the bergen hill tunnels) the pile of trap rock excavated from these tunnels, which had been dumped on the piece of waste ground to the north of baldwin avenue, weehawken, n. j. the general layout of the plant is shown on plate xxx. it consisted of a no. and a no. austin crusher, driven by an amex, single-cylinder, horizontal, steam engine of h.p., and was capable of crushing about cu. yd. of stone per -hour day. the crushers and conveyors were driven from a countershaft, in turn driven from the engine by an -in. belt. table .--cost of operating the one plant for hours during concrete lining. ===+===================+====================+============= no.| labor. | rate per day. | amount. ---+-------------------+--------------------+------------- |engineers | $ . | $ . |firemen | . | . |pumpmen | . | . |foreman electrician| . | . |electrician | . | . |laborer | . | . ---+-------------------+--------------------+------------- total per day | $ . --------------------------------------------+------------- total for days | $ . --------------------------------------------+------------- supplies. -----------------------+--------------------+------------- coal ( tons per day) | $ . | $ . oil ( gal. per day) | . | . water | . | . other supplies | . | . -----------------------+--------------------+------------- total per day | $ . --------------------------------------------+------------- total for days | $ , . --------------------------------------------+------------- total cost of labor and supplies for days| $ , . ============================================+============= the process of crushing was as follows: the stone from the pile was loaded by hand into scale-boxes which were lifted by two derricks into the chute above the no. crusher. one derrick had a -ft. mast and a -ft. boom, and was worked by a lidgerwood steam hoister; the other had a -ft. mast and a -ft. boom, and was worked by a "general electric" hoist. all the stone passed first through the no. crusher, after which it was lifted by a bucket conveyor to a screen, placed about ft. higher than and above the stone bin. the screen was a steel chute pierced by ½-in. circular holes, and was on a slope of about °; in order to prevent the screen from choking, it was necessary to have two men continually scraping the stone over it with hoes. all the stone passing the screen was discharged into a bin below with a capacity of about cu. yd. the stone not passing the screen passed down a diagonal chute to a no. crusher, from which, after crushing, it was carried back by a second bucket conveyor to the bin, into which it was dumped without passing a screen. the no. crusher was arranged so that it could, when necessary, receive stone direct from the stone pile. the cars in which the stone was removed could be run under the bin and filled by opening a sliding door in the bottom of the bin. a track was laid from the bin to connect with the contractor's surface railway in the weehawken shaft yard, and on this track the stone could be transported either to the weehawken shaft direct, for use on that side of the river, or to the wharf, where it could be dumped into scows for transportation to new york. the cars used were -cu. yd. side-dump, with flap-doors, and were hauled by two steam dinky locomotives. the average force employed was: foreman @ $ . per day. supervising. laborers " . " " loading scale-boxes for derricks. laborers " . " " feeding crushers. laborers " . " " watching screens to prevent clogging. engineer " . " " driving steam engine. engineers " . " " on the derricks. night watchman. watching the plant at night. owing to the constant break-down of machinery, chutes, etc., inseparable from stone-crushing work, there was always at work a repair gang consisting of either three carpenters or three machinists, according to the nature of the break-down. the approximate cost of the plant was: machinery $ , lumber , erection labor , ------ total $ , the cost of the crushed stone at weehawken amounted to about $ . per cu. yd., and was made up as follows: cost of stone $ . labor in operation of plant . plant supplies . [b]plant depreciation . ----- total $ . [b] assuming that the scrap value of derricks and engines is one-half the cost, crushers one-third the cost, and other items nothing. the crushed stone at the manhattan shaft cost about $ . per cu. yd., the difference of $ . from the weehawken cost being made up of the cost of transfer across the river, $ . , and transport from the dock to the shaft, $ . . _miscellaneous plant._--the various pieces of plant used directly in the construction work, such as derricks, hauling engines, pumps, concrete mixers, and forms, will be found described or at least mentioned in connection with the methods used in construction. the tunneling shields, however, will be described now, as much of the explanation of the shield-driven work will not be clear unless preceded by a good idea of their design. tunneling shields. during the period in which the original contract drawings were being made, namely, in the latter part of and the early part of , considerable attention was given to working out detailed studies for a type of shield which would be suitable for dealing with the various kinds of ground through which the shield-driven tunnels had to pass. this was done in order that, when the contract was let, the engineer's ideas of the requirements of the shields should be thoroughly crystallized, and so that the contractor might take advantage of this long-thought-out design, instead of being under the necessity of placing a hurried order for a piece of plant on which so much of the safety as well as of the speed of his work depended. eventually, the contractor took over these designs as they stood, with certain minor modifications, and the shields as built and worked gave entire satisfaction. the chief points held in view were ample strength, easy access to the working face combined with ease and quickness of closing the diaphragm, and general simplicity. a clear idea of the main features of the design can be gathered from fig. and plate xxxi. [a]the interior diameter of the skin was in. greater than the external diameter of the metal lining of the tunnel, which was ft. the skin was made up of three thicknesses of steel plate, a ¾-in. plate outside and inside, with a / -in. plate between; thus the external diameter of the skin was ft. ¼ in. the length over all (exclusive of the hood, to be described later) was ft. - / in. the maximum overlap of the skin over the erected metal lining was ft. ½ in., and the minimum overlap, ft. there were no inside or outside cover-plates, the joints of the various pieces of skin plates being butt-joints covered by the overlap of adjoining plates. all riveting was flush, both inside and outside. the whole circumference of each skin plate was made up of eight pieces, each of which extended the entire length of the shield, the only circumferential joint on the outside being at the junction of the removable cutting edge (or of the hood when the latter was in position) with the shield proper. forward of the back ends of the jacks, the shield was stiffened by an annular girder supporting the skin, and in the space between the stiffeners of which were set the propelling rams used to shove the shield ahead by pressure exerted on the last erected ring of metal lining, as shown on plate xxxi. to assist in taking the thrust of these rams, gusset-plates were placed against the end of each ram cylinder, and were carried forward to form level brackets supporting the cast-steel cutting-edge segments. the stiffening gussets, between which were placed the rams, were also carried forward as level brackets, for the same purpose. the cast-steel segmental cutting edge was attached to the front of the last mentioned plates. the interior structural framing consisted of two floors and three vertical partitions, giving nine openings or pockets for access to the face; these pockets were ft. in. wide, the height varying from ft. in. to ft. in., according to their location. the openings were provided with pivoted segmental doors, which were adopted because they could be shut without having to displace any ground which might be flowing into the tunnel, and while open their own weight tended to close them, being held from doing so by a simple catch. [illustration: proposed shield for subaqueous tunneling general elevation fig. .] for passing through the varied assortment of ground before entering on the true sub-river silt, it was decided to adopt the forward detachable extension, or hood, which has so often proved its worth in ground needing timber for its support, as shown in fig. , plate xxix. this hood extended ft. in. beyond the cutting edge, and from the top down to the level of the upper platform. additional pieces were provided by which the hood might have been brought down as far as the lower platform, but they were not used. special trapezoidal steel castings formed the junction between the hood and the cutting edge. the hood was in nine sections, built up of two ¾-in. and one / -in. skin plates, as in the main body of the skin, and was supported by bracket plates attached to the forward ends of the ram chambers. the hoods were bolted in place, and were removed and replaced by regular cutting-edge steel castings after the shields had passed the river lines. the floors of the two platforms, of which there were eight, formed by the division of the platforms by the upright framing, could be extended forward ft. in. in front of the cutting edge, or in. in front of the hood. this motion was given by hydraulic jacks. the sliding platform could hold a load of , lb. per sq. ft., which was equal to the maximum head of ground and water combined. the uses of these platforms will be described under the heading "construction." the weight of the structural portion of each shield was about tons. the remainder of the shield was the hydraulic part, which provided its motive force and gave the power to the segment erector. the hydraulic fittings weighed about tons per shield, so that the total weight of each shield was about tons. the hydraulic apparatus was designed for a maximum pressure of , lb. per sq. in., a minimum pressure of , lb., and a test pressure of , lb. the actual average pressure used was about , lb. per sq. in. there were shoving rams, with a diameter of ½ in. and stroke of in. the main ram was single-acting. the packings could be tightened up from the outside without removing the ram, a thing which is of the greatest convenience, and cannot be done with the differential plunger type. some of the chief figures relating to the shield rams, with a water pressure of , lb. per sq. in., are: forward force of one ram , lb. forward force of rams (all) , , " forward force of rams , tons of , lb. equivalent pressure per square inch of face lb. equivalent pressure per square foot of face , " pull-back force of one ram , " pull-back pressure on full area of ram " per sq. in. the rams developed a tendency to bend, under the severe test of shoving the shield all closed, or nearly so, through the river silt, and it is probable that it would have been better to make the pistons in. in diameter instead of ½ in. each sliding platform was actuated by two single-acting rams, ½ in. in diameter and having a stroke of ft. in. the rams were attached to the rear face of the shield diaphragm inside the box floors, and the cylinders were movable, sliding freely on bearings in the floor. the front ends of the cylinders were fixed to the front ends of the sliding platforms. the cylinder thus supported the front end of the sliding platform, and was designed to carry its half of the load on the platform. some of the leading figures in connection with the platform rams, at a working pressure of , lb. per sq. in., are: forward force of each pair of rams (in each platform) , lb. total area of nose of sliding platform , sq. in. maximum reaction per square inch on nose lb. maximum reaction per square foot on nose , " each shield was fitted with a single erector mounted on the rear of the diaphragm. the erector consisted of a box-shaped frame mounted on a central shaft revolving on bearings attached to the shield. inside of this frame there was a differential hydraulic plunger, in. and in. in diameter and of -in. stroke. to the plunger head were attached two channels sliding inside the box frame, and to the projecting ends of these the grip was attached. at the opposite end of the box frame a counterweight was attached which balanced about lb. of the tunnel segment at ft. radius. the erector was revolved by two single-acting rams fixed horizontally to the back of the shield above the erector pivot through double chains and chain wheels keyed to the erector shaft. the principal figures connected with the erector, assuming a water pressure of , lb. per sq. in., are: weight of heaviest tunnel segment , lb. weight of erector plunger and grip " total weight to be handled by the erector ram , " total force in erector ram moving from center of shield , " total force in erector ram moving toward center of shield , " weight at -ft. radius which is balanced by counterweight " maximum net weight at -ft. radius to be handled by turning rams , " total force of each rotating ram, at , lb. per sq. in. , " load at -ft. radius, equivalent to above , " when the shield was designed, a grip was also designed by which the erector could handle segments without any special lugs being cast on them. a bolt was passed through two opposite bolt holes in the circumferential flanges of a plate. the grip jaws closed over this bolt and locked themselves. the projecting fixed ends of the grip were for taking the direct thrust on the grip caused by the erector ram when placing a segment. it happened, however, that there was delay in delivering these grips, and, when the shield was ready to start, and the grip was not forthcoming, mr. patrick fitzgerald, the contractor's superintendent, overcame this trouble by having another grip made. in this design, also, a self-catching bolt is placed through the segment and the grip catches the bolt. in simplicity and effectiveness in working, this new design eventually proved a decided advance on the original one, and, as a result, all the shields were fitted with the new grip, and the original design was discarded. the great drawback to the original grip was that the plate swung on the lifting bolt, and thus brought a great strain on the bolt when held rigidly at right angles to the erector arm. the original design was able to handle both _a_ and _b_ segments, and key segments, without alteration; in the new design, an auxiliary head had to be swung into position to handle the key, but this objection did not amount to a practical drawback. the operating floor from which the shield was controlled, and at which the valves were situated, was placed above the rams which rotate the erector, and formed a protection for them. the control of the shield rams was divided into four groups: the seven lower rams constituted one group, the upper five, another, and the six remaining on each side, the other two. each group was controlled by its own stop and release valve. individual rams were controlled by stop-cocks. the control of the sliding platform rams was divided into two groups, of which all the rams on the upper floor made one, and all those in the lower floor, the other; here, again, each group had its own stop and release valve, and individual platforms were controlled by stop-cocks arranged in blocks from which the pipes were carried to the rams. the in-and-out movements of the erector ram were controlled by a two-spindle, balanced, stop and release valve, controlled by a hand-wheel. the erector rotating rams were controlled by a similar valve, with four spindles, also operated by a single hand-wheel. both wheels were placed inside the top shield pockets, and within easy reach of the operating platform. the hydraulic pressure was brought through the tunnel by a -in. hydraulic pipe. connection with the shield was made by a flexible copper pipe, the -in. line being extended as the shield advanced. land tunnels. general. the following is a brief account of the main features of the "land tunnel" work, by which is meant all the part of the structure built without using tunneling shields. the land tunnels consist of about ft. of double tunnel on the new york side and ft. on the new jersey side, or a total of , lin. ft. of double tunnel. the general design of the cross-section consists of a semi-circular arch, vertical side-walls and a flat invert. the tunnel is adapted for two lines of track, each being contained in its compartment or tunnel. the span of the arch is wider than is absolutely necessary to take the rolling stock, and the extra space is utilized by the provision of a sidewalk or "bench" forming by its upper surface a gangway, out of the way of traffic, for persons walking in the tunnels, and embedded in its mass are a number of vitrified earthenware ducts, for high-and low-tension electric cables. the provision of this bench enables its vertical wall to be brought much nearer to the side of the rolling stock than is usually possible, thus minimizing the effects of a derailment or other accident. refuge niches for trackmen, and ladders to the top of the bench are provided at frequent intervals. in cases where a narrow street limits the width of the structure, as on the new york side, the two tunnels are separated by a medial wall of masonry, thus involving excavation over the entire width of both tunnels, and in such case the tunnels are spoken of as "twin tunnels"; where the exigencies of width are not so severe, the two tunnels are entirely distinct, and are separated by a wall of rock. this type is found on the weehawken side. the arches are of brick, the remainder of the tunnel lining being of concrete. new york land tunnels. the work on the land tunnels on the manhattan side was carried on from the shaft at th avenue and d street. the plans and designs for these tunnels are shown on plate xxxii. in this short length of about ft. there are no less than nine different kinds of cross-section. the reason for these changes is the fact that the two lines of track are here not straight and parallel to the center line between the tunnels, but are curved, although symmetrical about this center line. the various changes of section are to enable the tunnels to be built in straight lengths, thus avoiding the disadvantages attending the use of curved forms, and at the same time minimizing the quantity of excavation, an item which accounts for from to % of the total cost of tunnels of this type. of course, there are corresponding and obvious disadvantages in the adoption of many short lengths of different cross-sections, and these disadvantages were well brought out in the course of the work; on the whole, however, they may be said to have justified their adoption. these new york land tunnels were divided into three contracts, viz.: from station + (the portal to the open work of the terminal station at the east side of tenth avenue, new york city) to station + , called "section gy-east." the next contract, called "section gy-west supplementary," extended from station + to station + , which is the east side of eleventh avenue. the third contract was called "section gy-west," and extended from station + to station + (the dividing line between the states of new york and new jersey). thus, for nearly all its length, this contract consists of shield-driven tunnel. the portion between stations + and + . , however, was of the land tunnel type, and therefore will be included here. a fourth contract extended from station + to the weehawken shaft at station + , and of this all but ft. was of the shield-driven type, only the portion next to the weehawken shaft being of the land tunnel type. the four contracts were let to one contractor (the o'rourke engineering construction company), and the work was carried on simultaneously in all four, so that the division into contracts had no bearing on the methods of work adopted, and these will now be described as a whole and with no further reference to the different sections. excavation. work was started on the new york side on april th, , the weehawken shaft being at that date still under construction. as will have been noted in the description of the shafts, the contractor found a shaft already prepared for his use, and cross-drifts at grade and at right angles to the future tunnels, and extending across their entire width. the first essential was to get access to the shield chambers, which were to lie about ft. to the west of the shaft, so that the construction of these enlargements in which the shields for the subaqueous tunnels were to be built might be finished as soon as possible and thus allow the earliest possible start to be made with the shield-driven tunnels. with this in view, two bottom headings, on the center line of each of the two tracks, were driven westward from the western cross-heading at the foot of the shaft. when about ft. had been made in this way, the two headings were brought together and a break-up was made to the crown level of the tunnel, as the depth of rock cover was doubtful. from this break-up a top heading was driven westward to station + . while widening the heading out at station + the rock was penetrated on the south side. the exposed wet sand and gravel started to run, and, as a consequence, a change in design was made, the shield chambers (and consequently the start of the shield-driven tunnels) being moved eastward from their original location ft. to their present location. a certain amount of time was necessarily spent in making these changes of design, which involved a rearrangement of the whole layout from the terminal station to the start of the river tunnels. on july th, , however, the new design was formally approved. no sooner had this been decided than a strike arose on the work, and this was not settled until august st, , but from that time the work progressed without delay. no further reference will be made to the work in the shield chambers, as that will come under the heading of "river tunnels," being of the segmental, cast-iron lined type. a top heading was now driven over the original bottom heading west of the shaft, and at the same time the original cross-drifts from the shaft were amalgamated with and broken down by a heading driven at the crown level of the "intercepting arch" which here cuts across the ordinary run of tunnel at right angles and affords access to the tunnels from the shafts. the excavation of the upper portion of the intercepting arch at its southern end gave some trouble, and caused some anxiety, as the rock cover was penetrated and the wet sand and gravel were exposed. this made it necessary to timber all this section heavily, and the tracks of the new york central railroad directly above were successfully supported. the general way in which this timbering was carried out will be described under the head of "timbering." meanwhile, the excavation of the tunnels west of the intercepting arch was continued until the north and south tunnels were taken out to their full outlines, leaving a core of rock between them. this core was gradually removed, and timbering supporting the rock above the middle wall was put in as excavation went on. the ground, which was entirely of micaceous schist, typical of this part of manhattan, seamed with veins of granite, was rather heavy at the west end, or adjacent to the shield chambers, and required complete segmental timbering across the whole span. one heavy fall of rock in the corewall between the north and south tunnels took place on november d, but fortunately did not extend beyond the limits of the permanent work. on november th, , the excavation east of the intercepting arch was begun by driving a bottom heading in the south tunnel. this was continued to station + and then was taken up to the crown level and worked as a top heading with the view of keeping track, by making exploratory borings upward from the roof at frequent intervals, of the rock surface, which was here irregular and not known with any degree of certainty. the work was not pressed with any vigor, because all efforts were then being bent toward excavating from the river tunnels as much rock as possible. in section gy-east the conditions were exceptionally variable, as the rock was subject to sudden changes from a soft crumbling mica schist to broad bands of hard granite, and, in addition, the rock surface was very irregular, and, for a good length of this section, was below the crown of the tunnel, a condition which led to the adoption of the cut-and-cover method for part of the work. the irregularity in conditions called for varying methods of procedure, but in general the methods were as shown on plate xxxiii, and described as follows: _in solid rock._--where there was plenty of good rock cover, a top middle heading was driven, which was afterward widened out to the full cross-section of the twin tunnel arches. if necessary, a few lengths of segmental timbering were put in before taking down the bench, which was generally kept some or ft. behind the breast of the heading. after the bench was down, the middle conduit trench was excavated and the trimming done. _in soft rock._--where there was not enough rock cover, or where there was actual soft ground in the roof, wall-plate headings at the springing line level were driven ahead of the remainder of the work. the wall-plates were laid in these, the roof was taken out in short lengths, and segmental timbering spanning from wall-plate to wall-plate was put in. the roof being thus held, the bench excavation proceeded without trouble. where the rock was penetrated and soft ground showed in the roof, poling boards were driven ahead over the crown-bars, as shown in fig. . _cut-and-cover work._--after some ft. had been driven from the intercepting arch, it was found that the crown of the tunnel was continually in soft ground. to ascertain the extent of this condition the contractor decided to make soundings as far as tenth avenue, which was done by sinking trial pits and making wash-borings in the street. these soundings showed that there would be soft ground in the crown from station + to station + (at one point to a depth of ft. below the crown), and on each side of this section the cover was insufficient from station + to station + . this condition being known, it was decided to adopt cut-and-cover work for this length, the principal reasons being that repairs to sewers, streets, and drains would be no more, and probably less, expensive than with the tunnel method; the underpinning of a heavy brick brewery building adjoining the works on the north side would be facilitated, and the opening in the street, through which muck and materials could be handled, would relieve the congested shaft, through which the large volume of muck from the river tunnels was then being conveyed. on the other hand, the cut-and-cover method was adversely affected by the presence of a heavy timber trestle built down the south side of the street and over which passed all the excavation from the terminal station, amounting to a very heavy traffic. as this trestle had to be supported, it complicated the situation considerably. very little active progress was made between june, , and april, , as the contractor's energies during that time were much taken up with the progress of the shield-driven tunnels. in april, , preparations were made to start a -ft. length of open cut, rangers being fixed and sheathing driven; and the sewer which ran down the middle of this street was diverted to the outside of the open-cut length. april and may were occupied in driving the sheathing down to rock, supporting the trestle, underpinning the adjoining brewery, and excavating the soft material above the rock. on june d, , rock was reached, and, by july st, the excavation was down to subgrade over nearly the whole ft. in the first length. in the meantime another length was opened up, and eventually a third. the surface of the rock now seemed to be rising, and the heavy buildings had been passed, so that tunneling was reverted to for the rest of the work, though many difficulties were caused by soft rock in the roof from time to time. [illustration: method of driving roof lagging in soft ground. fig. .] when the excavation for the open-cut work of the terminal station had advanced to the line of tenth avenue, the contractor started a heading from this point and drove westward under tenth avenue until the headings driven eastward from the cut-and-cover portion, were met. this was done to expedite the work under tenth avenue, where the ground was not very good, where there were several important gas and water mains in the street, and where, moreover, the tunnels were of exceptionally large span ( ft. in.), making a total width of some ft. for the excavation. the excavation for the new york tunnels was practically finished in january, . _drilling and blasting._--the foregoing short description will serve to show in a general way the scheme adopted in making the excavation. a few details on drilling and blasting methods may not be out of place. percussive drills run by air pressure were used. they were ingersoll-sergeant, nos. ½, a- , c- , and f- . the air came from the high-pressure compressor previously described. this compressor, without assistance, could supply air for nine drills, but, when fed by compressed air from the lower pressure, its capacity was increased three or four times. the air was compressed to lb. per sq. in. in the power-house, and was delivered at about lb. per sq. in. at the drills. a -in. air line was used. the drill steel was - / -to - / -in. octagonal. the holes were about ¼ in. in diameter at starting and - / in. at the full depth of ft. the powder used on the new york side was % forcite, the near presence of heavy buildings and lack of much rock cover necessitating light charges and many holes spaced close together. to compensate the contractor for the inevitable excavation done outside the neat lines of the masonry lining, the excavation was paid for to the "standard section line" which was in. outside the neat lines on top and sides and in. outside at the bottom of the cross-section. the actual amount of excavation done was about % greater than that paid for. the distance excavated beyond the neat line, because of the very heavy timbering necessary, was about . ft. instead of the ft. allowed, and at the bottom about . ft. instead of the . ft. paid for. for a period of months detailed records were kept of the drilling and blasting. about , cu. yd. of excavation are included. a sketch and table showing the method of driving the heading, the number and location of the holes drilled, and the amount of powder used, is given in fig. . from this and similar figures the information in table is derived. table . +========================+=======+=======+=======+======+=======+======| | | feet of hole | pounds of powder | | |drilled per cubic yard | used per cubic yard | | | of excavation. | of excavation. | | +-------+-------+-------+------+-------+------| |portion of excavation. | -ft. | -ft. | -ft. | | | | | | -in. | -in. | -in. | -ft.| -ft. | -ft.| | |span-- |span-- |span-- | -in. | -in. | -in.| | | twin | twin | twin | | | | | |tunnel.|tunnel.|tunnel.| | | | |------------------------+-------+-------+-------+------+-------+------+ |wall-plate heading[c] | . | . | . | . | . | . | | | | | | | | | |total heading[c] | . | . | . | . | . | . | | | | | | | | | |bench and raker bench[c]| . | . | . | . | . | . | | | | | | | | | |trench[c] | . | . | . | . | . | . | |------------------------+-------+-------+-------+------+-------+------+ |average for section[c] | . | . | . | . | . | . | |------------------------+-------+-------+-------+------+-------+------| |actual amount[d] | . | . | . | . | . | . | +========================+=======+=======+=======+======+=======+======+ [c] figures taken from typical cross-sections. [d] this gives the actual amount of drilling done and powder used per cubic yard for the whole period of months of observation, but as this length included ft. of heading and only ft. of bench, the average figures (for powder especially) are too low. table gives the rate and cost of drilling, and the cost of powder. it will be seen that the average rate of drilling was . ft. per hour per drill or . ft. per drill per shift. table shows the result of observation as to the time taken in various subdivisions of the drilling operations. these observations were not carried on for a long enough period to give correct results, but the percentages of time spent on each division of the operation are believed to be about right. the headings of this table are self-explanatory. the necessary delays include all time spent in changing bits, making air-line connections, etc. the unnecessary delays are stoppages caused by lack of supplies or insufficient air pressure. by table it will be noticed that the cost of labor for drilling and sharpening steels was about $ . per lin. ft. of hole drilled. the total cost, including repairs, supply of air, etc., came to about $ . , as will be seen from table . _timbering._--on the new york side nearly the whole length of the excavation needed timbering, to a greater or less extent, and for the most part required timbering of quite a heavy type. table .--rock tunnel excavation under d street, east of cut-and-cover section. drilling and blasting.--detailed cost of labor in drilling, also quantity and cost of powder used. +=====================================================================+ | drilling and blasting. | |-----+-----+------+------+------+-----+-----+------+-----+-----+-----| |type.|date.|total feet drilled. | no. drill shifts| feet drilled | | | | | | | of ( -hour.) |per man per hour.| | +-----+------+------+------+-----+-----+------+-----+-----+-----+ | | |head- |bench |total |head-|bench|total |head-|bench|total| | | | ing | | | ing | | | ing | | | |-----+-----+------+------+------+-----+-----+------+-----+-----+-----+ |_ke._|may | , | , | , | | | | . | . | . | | |june | , | , | , | | | | . | . | . | | |july | | , | , | | | | | . | . | | |aug. | | , | , | | | | | . | . | | |sept.| | , | , | | | | | . | . | | +-----+------+------+------+-----+-----+------+-----+-----+-----+ | |total| , | , | , | | | , | . | . | . | |-----+-----+------+------+------+-----+-----+------+-----+-----+-----+ |_ki._|may | , | | , | | | | . | | . | | |june | , | | , | | | | . | | . | | |july | | , | , | | | | | . | . | | |aug. | | , | , | | | | | . | . | | |estim| | , | , | | | | | . | . | | +-----+------+------+------+-----+-----+------+-----+-----+-----+ | |total| , | , | , | | | , | . | . | . | |-----+-----+------+------+------+-----+-----+------+-----+-----+-----+ |_ko._|may | | , | , | | | | | . | . | | |june | | , | , | | | | | . | . | | |july | | , | , | | | | | . | . | | |aug. | | , | , | | | | | . | . | | |estim| | , | , | | | | | . | . | | +-----+------+------+------+-----+-----+------+-----+-----+-----+ | |total| | , | , | | | | | . | . | |-----+-----+------+------+------+-----+-----+------+-----+-----+-----+ |grand|total| , | , | , | | , | , | . | . | . | +=====+=====+======+======+======+=====+=====+======+=====+=====+=====+ +==================================================+=====================+ | drilling and blasting | powder used. | |-----+----------+------+--------------------------+--------+-------+----+ | | | | cost of labor only. | | | | | | | | drilling and sharpening. | | | | | | | +------+------+-------+----+ | | | | | | | | | per | | | cost | | | | | | | | cubic | | | per | | | | | | | | yard. | | | cubic | | | | | | | | | | |yard at| | | | | | | | | | | | | | | | | | | | | | cents | | | | | | | | | | | per | | | | | | | | | | |pound. | | | +----------+------+------+------+-------+----+--------+-------+----+ |type.| quantity | |total.| per |actual.|paid| total |actual.|paid| | | of | | |linear| |for |quantity| |for.| | |excavation| | |feet. | | | | | | | | in cubic | | | | | | | | | | | yards. | | | | | | | | | | +----------+------+------+------+-------+----+--------+-------+----+ | | actual. | paid | $ | $ | $ | |pounds. | $ | $ | | | [e] | for | | | | | | | | | | | [f] | | | | | | | | |-----+----------+------+------+------+-------+----+--------+-------+----+ |_ke._| , | , | , | . | . | . | , | . | . | | | | | , | . | . | . | , | . | . | | | , | | , | . | . | . | | . | . | | | | | | . | . | . | | . | . | | | | | | . | . | . | | . | . | | |----------+------+------+------+-------+----+--------+-------+----+ | | , | , | , | . | . | . | , | . | . | |-----+----------+------+------+------+-------+----+--------+-------+----+ |_ki._| | | , | . | . | . | , | . | . | | | | | , | . | . | . | , | . | . | | | | | , | . | . | . | | . | . | | | | | , | . | . | . | | . | . | | | , | , | , | . | . | . | , | . | . | | |----------+------+------+------+-------+----+--------+-------+----+ | | , | , | , | . | . | . | , | . | . | |-----+----------+------+------+------+-------+----+--------+-------+----+ |_ko._| | | | . | . | . | | . | . | | | | | | . | . | . | | . | . | | | | | , | . | . | . | | . | . | | | | | , | . | . | . | | . | . | | | | | , | . | . | . | | . | . | | |----------+------+------+------+-------+----+--------+-------+----+ | | , | , | , | . | . | . | , | . | . | | |---------+-------+------+------+-------+----+--------+-------+----+ | | , | , | , | . | . | . | , | . | . | +=====+==========+======+======+======+=======+====+========+=======+====+ the work done during the months when these analyzed cost figures were kept includes ft. of bench and ft. of heading. this excess of bench over heading causes the general average amounts per cubic yard to be too low. [e] actual amount of excavation. [f] amount of excavation paid for. [illustration: ' " span twin tunnels details of method of drilling and blasting in a typical (not exact average) section] +---------+--------+--------+-----+-----+------+------+-------+ | drilling and firing data for | | each sub-division of section | |---------+--------+--------+-----+-----+------+------+-------| | sub | volume | no. of | no. | no. |total |linear| total | |divisions|of each |sets of | of | of | lbs. | feet |length | | | sub- | holes |holes|times| of | of |drilled| | |division| | in |fired|powder|tunnel| | | |paid for| | set | | per |broken| | | | | | | | hole | | | | | | | | |fired | | | |---------+--------+--------+-----+-----+------+------+-------| | _a_ | _b_ | _c_ | _d_ | _e_ | _f_ | _g_ | _h_ | |---------+--------+--------+-----+-----+------+------+-------| | _a_ | . | {[g] | | | . | | | | | | {[h] | | | . | | | | | | {[i] | | | . | | | | | | {[j] | | | . | . | | | | | | | | | | | |---------+--------+--------+-----+-----+------+------+-------| | _a'_ | . | | - | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | _b_ | . | {[g] | - | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | _c_ | | {[k] | | | . | | | | | . | | | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | _d_ | . | | - | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | | | | | | | | |=========+========+========+=====+=====+======+======+=======| | _e_ | . | | | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | _f_ | . |{ . | | | . | | | | | |{[l] . | | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | _g_ | . | . | | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | | | | | | | | |=========+========+========+=====+=====+======+======+=======| | _h_ | . |{ | | | . | | | | | |{ | | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | _i_ | . | | | | . | . | | |---------+--------+--------+-----+-----+------+------+-------| | | | | | | | | | | |========+=====+=====+======+======+=======| | | | | | | | | | | | | | | |========+=====+=====+======+======+=======| | | | | +---------+--------+--------+-----+-----+------+------+-------+ +---------+------+-------+------+------+---------+-------+------+ | drilling and firing data for | | total sections | |---------+------+-------+------+------+---------+-------+------| | sub |total |length | cu. | cu. | total | total | total| |divisions|length|drilled| yds. | yds. | lbs. of |lbs. of| lbs. | | | of | per | per | per | powder | powder| of | | |simi- |linear |linear|linear| per | per |powder| | |lar |foot of| foot | foot | linear | foot | per | | |head- |tunnel | of | of | foot of |drilled|cubic | | |ings | |tunnel|tunnel| tunnel | | yard | |---------+------+-------+------+------+---------+-------+------| | _a_ | _i_ | _j_ | _k_ | _l_ | _m_ | _n_ | _o_ | |---------+------+-------+------+------+---------+-------+------| | _a_ | |sigma | | | | | | | | | c + d |b + i | j |c + d + f| m | m | | | | ----- |------| --- | ----- | --- | --- | | | | g | g | k | g | j | k | | | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _a'_ | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _b_ | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _c_ | | | | | | | | | | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _d_ | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| |total for| | . | . | . | . | . | . | | heading | | | | | | | | |=========+======+=======+======+======+=========+=======+======| | _e_ | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _f_ | | | | | | | | | | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _g_ | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| |total for| | . | . | . | . | . | . | | bench | | | | | | | | |=========+======+=======+======+======+=========+=======+======| | _h_ | | | | | | | | | | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| | _i_ | | . | . | . | . | . | . | |---------+------+-------+------+------+---------+-------+------| |total of | | . | . | . | . | . | . | | trench | | | | | | | | |=========+======+=======+======+======+=========+=======+======| |total for| | . | . | . | . | . | . | | whole | | | | | | | | |section | | | | | | | | |=========+======+=======+======+======+=========+=======+======| |powder taken at . lb. per stick | +---------+------+-------+------+------+---------+-------+------+ [g] cut holes- feet (black circle) [h] first side rd. and bottom- feet (circle with dot in it) [i] back round- feet (circle with line in it) [j] top back round- feet (circle with x in it) [k] a' holes- feet (open circle) [l] line holes (plus sign) table .--analysis of drilling time on section gy-east. +========+======+========+=====+=====+=======+========+========+=======+ | | | | average time taken: | |position|nature| no. of |-----+-----+-------+--------+--------+-------| | in | of | drill | | | | | | | |section.|rock. | shifts |set- |dril-|neces- |unneces-| taking |loading| | | |observed|ting |ling.| sary | sary | down | and | | | | for | up. | |delays.|delays. |machine.|firing.| | | |average.| | | | | | | |--------+------+--------+-----+-----+-------+--------+--------+-------| | | | |h. m.|h. m.| h. m. | h. m. | h. m. | h. m. | | | | |-----+-----+-------+--------+--------+-------| |heading |quartz| | : | : | : | | : | : | | | | | | | | | | | |heading | hard | | : | : | : | | | | | | mica | | | | | | | | | |schist| | | | | | | | | | | | | | | | | | | bench |quartz| | : | : | : | : | : | : | | | | | | | | | | | | bench |medium| | : | : | : | : | : | : | | | mica | | | | | | | | | |schist| | | | | | | | | | | | | | | | | | | center |medium| | : | : | : | : | : | : | | trench | mica | | | | | | | | | |schist| | | | | | | | | | | | | | | | | | | center | soft | | : | : | : | : | : | : | | trench | mica | | | | | | | | | |schist| | | | | | | | |--------+------+--------+-----+-----+-------+--------+--------+-------| |general | | | : | : | : | : | : | : | |average | | | | | | | | | |--------+------+--------+-----+-----+-------+--------+--------+-------| | per- | | | . %| . %| . % | . % | . % | % | |centage | | | | | | | | | +========+======+========+=====+=====+=======+========+========+=======+ +========+======+=========+========+======+======+========+ | | | average time taken: | feet drilled. | |position|nature|---------+--------+------+------+--------| | in | of | | | | | | |section.|rock. | total |mucking.|total.| per | per | | | |drilling.| | |shift.|working | | | | | | | | hour. | | | | | | | | | |--------+------+---------+--------+------+------+--------| | | | h. m. | h. m. |h. m. | | | | | |---------+--------+------+------+--------| |heading |quartz| : | : | : | . | . | | | | | | | | | |heading | hard | : | | : | . | . | | | mica | | | | | | | |schist| | | | | | | | | | | | | | | bench |quartz| : | | : | . | . | | | | | | | | | | bench |medium| : | : | : | . | . | | | mica | | | | | | | |schist| | | | | | | | | | | | | | | center |medium| : | : | : | . | . | | trench | mica | | | | | | | |schist| | | | | | | | | | | | | | | center | soft | : | | : | . | . | | trench | mica | | | | | | | |schist| | | | | | |--------+------+---------+--------+------+------+--------| |general | | : | : | : | . | . | |average | | | | | | | |--------+------+---------+--------+------+------+--------| | per- | | . % | . % | % | | | |centage | | | | | | | +========+======+=========+========+======+======+========+ table .--analyzed cost of drilling. +=============+===========================+===========================+ | | cost per foot of hole | cost per drill shift | |item of cost.| drilled. | | | +-------+-----+-----+-------+-----+------+------+-------+ | | ft | ft| ft|average| ft| ft | ft |average| | | in | in| in| | in| in | in | | |-------------+-------+-----+-----+-------+-----+------+------+-------+ |drilling | $ . |$ . |$ . | $ . |$ . | $ . | $ . | $ . | |labor | | | | | | | | | | | | | | | | | | | |sharpening | . | . | . | . | . | . | . | . | | | | | | | | | | | |drill steel | . | . | . | . | . | . | . | . | |( in. per | | | | | | | | | |drill shift) | | | | | | | | | | | | | | | | | | | |drill repairs| . | . | . | . | . | . | . | . | | | | | | | | | | | |high-pressure|[m] . | . | . | . | . | . | . | . | |air | | | | | | | | | |-------------+-------+-----+-----+-------+-----+------+------+-------+ |totals | $ . |$ . |$ . | $ . |$ . |$ . |$ . |$ . | +=============+=======+=====+=====+=======+=====+======+======+=======+ [m] this is an estimated figure, ascertained by taking a proportion of the whole charge for plant running. _general methods._--whenever any considerable support was needed for the ground, segmental timbering was used. in most cases, this was supported by wall-plates at the springing line, and was set with an allowance for settlement, so that it would be clear of the work when the masonry lining was put in. as the twin-tunnel section involved the excavation of the north and south tunnels at the same time, the cross-section of the upper part of the excavation consisted of two quadrants rising from the springing line and connected at the top by a horizontal piece from to ft. in length. this made a rather flat arch to support by timbering. the timber for the segmental work was by -in. yellow pine. in light ground the bents were spaced at -ft. centers, in heavy ground -ft. -in. centers. when the soft ground in the roof was struck, posts had to be used in the heading to support the caps. when the bench was removed, the posts were replaced by others down to the bottom of the excavation. these long posts were a great hindrance to all the work, and each replacement of short posts by long ones meant a settlement of the caps; consequently, it was decided to use in the section east of the cut-and-cover, where all the ground was heavy, a temporary inner bent of segmental timber, within and reinforcing the permanent bent, and resting on separate wall-plates. this is shown by fig. . these temporary bents were inside the work, and were removed as the arch was built. however, the caps settled considerably in some cases, so that it was not possible to do away with posting entirely. in heavy ground the caps were set about ft. above the neat line of the crown of the brick arch, in some cases they were set only in. above, but the settlement was often more than this, causing great trouble in cutting out the encroaching timber when the arch had to be built. [illustration: details of longitudinal sectional showing method of placing lagging in crown with soft roof typical section looking east fig. .] in the tunnels east of the cut-and-cover portion, wall-plate headings were driven (shown by areas marked _a_ on fig. ), and, when a length of wall-plate had been set, the full-width heading was advanced a foot or two at a time, the timber segmental bents being set up as soon as possible; lagging was then driven over the cap into the soft ground. fig. shows the double set of segmental bents adopted in the -ft. -in. twin tunnels east of the cut-and-cover section. when the soft ground came down so low as to interfere with the excavation of the wall-plate headings, a small heading was driven into the soft ground on the line of the ends of the caps, and lagging was driven down from this to the wall-plate heading, as illustrated in fig. . in the -ft. -in. tunnels the wall-plate for the inner bent was supported by a side-bench, termed the "raker" bench. this was left in position until the rest of the bench and the middle subgrade conduit trench had been excavated; it was then possible to support the caps by two rows of posts from subgrade level, take out the inner bents, and excavate the raker bench. the -ft. -in. twin tunnels, which are at the extreme eastern end of this section, adjoining the open-cut work of the terminal station, and under tenth avenue, were driven from the terminal station-west, and the timbering had to be made very secure on account of the pipes and sewers in the street above. detailed records were kept of the amount of timber used and the cost of labor and material expended in timbering. these records cover the same portion of tunnel as that for which the detailed records of drilling costs, previously referred to, were kept. these records are shown in tables and . it will be noted that the timber used in blocking, that is, filling up voids outside the main timbering, amounted to more than two-thirds of the total timber, and that the cost of labor in erecting the timbering exceeds the prime cost of the timber by about one-third. the following distinction is made between permanent and temporary timbering: the permanent timbering is that which is concreted in when the masonry is built; the temporary consists of the lower bents and posts, which have to be removed when the masonry is built. _force employed in excavation._--a typical day's working force for drilling, blasting, mucking, and timbering is shown in table . where there was any large quantity of soft ground in the roof, the timber gang was much larger than shown in table , and was helped by the mucking gang. the drillers did most of the mucking out of the heading before setting up the drills. _excavation of weehawken rock tunnels._--this subject may be dismissed in a few words, as very few features of interest were called into play. the rock was of good quality, being the sandstone typical of this part of the country. little or no timbering was needed, there were no buildings above the tunnel to be taken care of, and large charges of powder could be used. table .--supplementary analysis of timbering, rock tunnel excavation under d street, east of cut-and-cover section. analyzed cost of timbering, per foot run and per bent. +=============================+================================ | | _ke_ | |--------+------------+---------- | |per foot|per bent, |per cubic | |run of | ft, in.,|yard | |tunnel |center to |excavation | | |center | |-----------------------------+--------+------------+---------- |permanent timbering. | | | |lumber in feet, b. m. | | | | upper bent. | | | . | blocking. | | | . | total. | | , | . |cost, in dollars. | | | | lumber. | . | . | . | labor. | . | . | . | total. | . | . | . | | | | |temporary timbering. | | | |lumber in feet, b. m. | | | | lower bent. | | . | . | blocking. | | | . | total. | | . | . |cost, in dollars. | | | | lumber. | . | . | . | erection labor. | . | . | . | removal labor. | . | . | . | total labor. | . | . | . | total. | . | . | . | | | | |grand total. | | | |lumber in feet, b. m. | , | , | . |cost, in dollars. | | | | lumber. | . | . | . | labor. | . | . | . | total. | . | . | |-----------------------------+--------+------------+---------- | | _ki_ | |--------+------------+---------- | |per foot|per bent, |per cubic | |run of | ft, in.,|yard | |tunnel |center to |excavation | | |center | |-----------------------------+--------+------------+---------- |permanent timbering. | | | |lumber in feet, b. m. | | | | upper bent. | | | . | blocking. | | | . | total. | | , | . |cost, in dollars. | | | | lumber. | . | . | . | labor. | . | . | . | total. | . | . | . | | | | |temporary timbering. | | | |lumber in feet, b. m. | | | | lower bent. | . | . | . | blocking. | . . | . | total. | . | . | . |cost, in dollars. | | | | lumber. | . | . | . | erection labor. | . | . | . | removal labor. | . | . | . | total labor. | . | . | . | total. | . | . | . | | | | |grand total. | | | |lumber in feet, b. m. | . | . | . |cost, in dollars. | | | | lumber. | . | . | . | labor. | . | . | . | total. | . | . | . |-----------------------------+--------+----------------------- | | _ko_ | |--------+------------+---------- | |per foot|per bent, |per cubic | |run of | ft, in.,|yard | |tunnel |center to |excavation | | |center | |-----------------------------+--------+------------+---------- |permanent timbering. | | | |lumber in feet, b. m. | | | | upper bent. | | | . | blocking. | | , | . | total. | | . | . |cost, in dollars. | | | | lumber. | . | . | . | labor. | . | . | . | total. | . | . | . | | | | |temporary timbering. | | | |lumber in feet, b. m. | | | | lower bent. | | , | . | blocking. | | | . | total. | | , | . |cost, in dollars. | | | | lumber. | . | . | . | erection labor. | . | . | . | removal labor. | . | . | . | total labor. | . | . | . | total. | . | . | . | | | | |grand total. | | | |lumber in feet, b. m. | , | , | . |cost, in dollars. | | | | lumber. | . | . | . | labor. | . | . | . | total. | . | . | . +=============================+========+============+========= table .--timbering:--detailed cost of timber, labor, and superintendence. rock tunnel excavation under d street, east of cut-and-cover section. +====+=======+======================================+====================+ | | | | excavation | | | | | timber used, in | in cubic | cost of | | | | feet, b. m. | yards | timber | | | |------------------------+-------------+--------------------+ | | | main |blocking| total | | paid | | | | | |date |timber.|timber. |timber.|actual| for. | main |block.|total.| | |-------+-------+--------+-------+------+------+------+------+------+ | | | _a_ | _b_ | _c_ | _d_ | _e_ | _f_ | _g_ | _h_ | | |-------+-------+--------+-------+------+------+------+------+------+ |_ke_|may | , | , | , | , | , | $ | $ |$ , | | |june | , | , | , | | | | | , | | |july | , | , | , | , | | | | , | | |august | , | , | , | | | | | | | |sept. | , | , | , | | | | | | | |removal| | | | | | | | | | |-------+-------+--------+-------+------+------+------+------+------+ | |total | , | , | , | , | , |$ , |$ , |$ , | |----+-------+-------+--------+-------+------+------+------+------+------+ |_ki_|may | | , | , | | | | $ | $ | | |june | | | | | | $ | | | | |july | , | , | , | | | | | | | |august | , | , | , | | | | | , | | |sept. | , | , | , | , | , | | | , | | |removal| | | | , | , | | | | | |-------+-------+--------+-------+------+------+------+------+------+ | |total | , | , | , | , | , |$ , | $ |$ , | |----+-------+-------+--------+-------+------+------+------+------+------+ |_ko_|may | , | , | , | | | $ | $ | $ | | |june | , | , | , | | | | | | | |july | , | | , | | | | | | | |august | , | , | , | | | | | | | |sept. | , | | , | | | | | | | |removal| | | | | | | | | |----|-------+-------+--------+-------+------+------+------+------+------+ | |total | , | , | , | , | , |$ , | $ |$ , | |----|-------+-------+--------+-------+------+------+------+------+------+ | |grand | , | , | , | , | , |$ , |$ , |$ , | | |total | | | | | | | | | +====+=======+=======+========+=======+======+======+======+======+======+ +====+=======+=======+=======+=======+=======+======+=======+=====+=====| | | | | | cost per | cost per | | | | | | cubic yard | cubic yard | | | |cost of| total | (actual). | (paid for). | | | | labor | cost. |-------+-------+------+-------+-----+-----+ | |date | | |timber.|labor. |total.|timber.|labor|total| | |-------+-------+-------+-------+-------+------+-------+-----+-----+ | | | | | _h_ | _i_ | _j_ | _h_ | _i_ | _j_ | | | | | | --- | --- | --- | --- | --- | --- | | | | _i_ | _j_ | _d_ | _d_ | _d_ | _e_ | _e_ | _e_ | |----+-------+-------+-------+-------+-------+------+-------+-----+-----+ |_ke_|may | $ , | $ , | $ . | $ . | $ . | $ . |$ . |$ . | | |june | , | , | . | . | . | . | . | . | | |july | , | , | . | . | . | . | . | . | | |august | | | . | . | . | . | . | . | | |sept. | | | . | . | . | . | . | . | | |removal| | | | | | | | | | |-------+-------+-------+-------+-------+------+-------+-----+-----+ | |total | $ , |$ , | $ . | $ . | $ . | $ . |$ . |$ . | |----+-------+-------+-------+-------+-------+------+-------+-----+-----+ |_ki_|may | $ | $ | $ . | $ . | $ . | $ . |$ . |$ . | | |june | | | . | . | . | . | . | . | | |july | | , | . | . | . | . | . | . | | |august | , | , | . | . | . | . | . | . | | |sept. | , | , | . | . | . | . | . | . | | |removal| , | , | | . | . | | . | . | | |-------+-------+-------+-------+-------+------+-------+-----+-----+ | |total | $ , | $ , | $ . | $ . | $ . | $ . |$ . |$ . | |----+-------+-------+-------+-------+-------+------+-------+-----+-----+ |_ko_|may | $ | $ | $ . | $ . | $ . | $ . |$ . |$ . | | |june | | , | . | . | . | . | . | . | | |july | | | . | . | . | . | . | . | | |august | | , | . | . | . | . | . | . | | |sept. | | | . | . | . | . | . | . | | |removal| | | | . | . | | . | . | | |-------+-------+-------+-------+-------+------+-------+-----+-----+ | |total | $ , | $ , | $ . | $ . | $ . | $ . |$ . |$ . | |----+-------+-------+-------+-------+-------+------+-------+-----+-----+ | |grand |$ , |$ , | $ . | $ . | $ . | $ . |$ . |$ . | | |total | | | | | | | | | +====+=======+=======+=======+=======+=======+======+=======+=====+=====+ +====+===========+======================+ | | | cost, per , | | | | ft., b. m., of | | | | total timber. | | | |-------+------+-------| | | | total | | | | | date |timber.|labor.|total. | | |-----------+-------+------+-------| | | | _h_ | _i_ | _j_ | | | | --- | --- | --- | | | | _c_ | _c_ | _c_ | |----+-----------+-------+------+-------| |_ke_|may |$ . |$ . | $ . | | |june | . | . | . | | |july | . | . | . | | |august | . | . | . | | |sept. | . | . | . | | |removal | | | | | |-----------+-------+------+-------| | |total |$ . |$ . |$ . | |----+-----------+-------+------+-------| |_ki_|may |$ . |$ . | $ . | | |june | . | . | . | | |july | . | . | . | | |august | . | . | . | | |sept. | . | . | . | | |removal | | | | | |-----------+-------+------+-------| | |total |$ . |$ . | $ . | |----+-----------+-------+------+-------| |_ko_|may |$ . |$ . | $ . | | |june | . | . | . | | |july | . | . | . | | |august | . | . | . | | |sept. | . | . | . | | |removal | | | | | |-----------+-------+------+-------| | |total |$ . |$ . | $ . | |----+-----------+-------+------+-------| | |grand total|$ . |$ . | $ . | +====+===========+=======+======+=======+ work was begun on september st, , immediately on the completion of the work on the shaft. the north and south tunnels in this case are completely independent, as will be seen from plate xxxiv. the procedure adopted was to drive a top heading on the center line of each tunnel and to break down the bench from this. the drilling was at first supplied with steam power from a temporary plant, as the contractor was at that time installing his permanent plant, which was finished at the end of november, . at this time the rate of advance averaged ½ lin. ft. of full section per day of hours. by the end of january the weehawken rock tunnels were completely excavated, and by the middle of april, , the excavation for the shield chambers was finished; the erection of the shields was started at the end of that month. table . ==================+=========+========+=============+========+========== grade. |total no.|rate per|drilling and |mucking:|timbering: | | day. |blasting: no.| no. | no. ------------------+---------+--------+-------------+--------+---------- superintendent | | $ . | ½ | / | / assistant engineer| | . | ½ | / | / electrician | | . | ½ | / | / engineer | | . | | | signalman | | . | | | foreman | | . | | | driller | | . | | | driller's helper | | . | | | laborers | | . | | | timbermen | | . | | | " helpers | | . | | | machinist | | . | | | blacksmith | | . | | | " helper | | . | | | nipper | | . | | | waterboy | | . | | | ------------------+---------+--------+-------------+--------+--------- total | | | ½ | - / | - / ==================+=========+========+=============+========+========= the general scheme of excavation is shown by plate xxxiii. the bench was kept or ft. behind the face of the heading. the powder used was % forcite. the general system of drilling was as shown in fig. . the average length of hole drilled per cubic yard of excavation was . ft., as against . ft. at manhattan; and the amount of powder used was . lb. per cu. yd., as against . lb. at manhattan. there was little timbering. a length of about or ft. adjoining the weehawken shaft was timbered, and also a shattered seam of about ft. in width between stations + and + . [illustration: land tunnels typical method of drilling used in the weehawken tunnels fig. ] the two entirely separate tunnels gave a cross-section which was much more easily timbered than the wide flat span at manhattan, and the segmental timbering was amply strong without posts or other reinforcement. table is a summary of the cost of excavating the land tunnels, based on actual records carefully kept throughout the work. table .--cost of excavation of land tunnels, in dollars per cubic yard. ======================================+=========+=========+============= | | |total yardage | | | and |manhattan|weehawken|average cost. --------------------------------------+---------+---------+------------- cubic yards excavated | , | , | , _labor._ | | | surface transport | $ . | $ . | $ . drilling and blasting | . | . | . mucking | . | . | . timbering | . | . | . --------------------------------------+---------+---------+------------- total labor | $ . | $ . | $ . --------------------------------------+---------+---------+------------- _material._ | | | drilling | $ . | $ . | $ . blasting | . | . | . timber | . | . | . --------------------------------------+---------+---------+------------- total material | $ . | $ . | $ . --------------------------------------+---------+---------+------------- plant running | $ . | $ . | $ . surface labor, repairs and maintenance| . | . | . field office administration | . | . | . --------------------------------------+---------+---------+------------- total field charges | $ . | $ . | $ . --------------------------------------+---------+---------+------------- chief office administration | $ . | $ . | $ . plant depreciation | . | . | . street and building repairs | . | | . --------------------------------------+---------+---------+------------- total average cost per cubic yard | $ . | $ . | $ . ======================================+=========+=========+============= masonry lining of land tunnels. plates xxxii and xxxiv show in detail the tunnels as they were actually built. it will be seen that in all work, except in the gy-east contract, there was a bench at each side of each tunnel in which the cable conduits were embedded. in gy-east the bank of ducts which came next to the middle wall was carried below subgrade, and the inner benches were omitted. the side-walls and subgrade electric conduits were water-proofed with felt and pitch. the water-proofing was placed on the outside of the side-walls (that is, on the neat line), and the space between the rock and the water-proofing was filled with concrete. this concrete was called the "sand-wall." the general sequence of building the masonry lining is shown in fig. . the operations were as follows: .--laying concrete for the whole height of the sand-walls, and for the floor and foundations for walls and benches up to the level of the base of the conduits; .--water-proofing the side-walls, and, where there was a middle trench containing subgrade conduits, laying and water-proofing these conduits; .--building concrete wall for conduits to be laid against, and, where there was a middle trench, filling up with concrete between the conduits; .--laying conduits; .--laying concrete for benches and middle-wall; .--building haunches from top of bench to springing of brick arch; .--building brick arch and part of concrete back-filling; .--finishing back-filling. the whole work will be generally described under the headings of concrete, brickwork, water-proofing, and electric conduits. _concrete._--the number of types and the obstructions caused by the heavy posting of the timbering made it inadvisable to use built-up traveling forms at the manhattan side, though they were used in the weehawken rock tunnels. the specifications required a facing mixture of mortar to be deposited against the forms simultaneously with the placing of the concrete. this facing mixture was dry, about in. thick, and was kept separate from the concrete during the placing by a steel diaphragm. the diaphragm was removed when the concrete reached the top of each successive layer, and the facing mixture and concrete were then tamped down together. this method was at first followed and gave good results, which was indeed a foregone conclusion, as the weehawken shaft had been built in this way. however, it was found that as good results, in the way of smooth finish, were to be obtained without the facing mixture by spading the concrete back from the forms, so that the stone was forced back and the finer portion of the mixture came against the forms; this method was followed for the rest of the work. all corners were rounded off on a -in. radius by mouldings tacked to the forms. the side-bench forms were used about four times, and were carefully scraped, planed, filled at open joints, and oiled with soap grease each time they were set up. when too rough for face work they were used for sand-wall and other rough work. the mixing was done by a no. ransome mixer, driven by -h.p. electric motors. the mixer at manhattan was set on an elevated platform at the north end of the intercepting arch; that at weehawken was placed at the entrance to the tunnels. the sand and stone were stored in bins above the mixers, and were led to the hoppers of the mixers through chutes. the hoppers were divided into two sections, which gave the correct quantities of sand and stone, respectively, for one batch. the water was measured in a small tank alongside. a "four-bag" batch was the amount mixed at one time, that is, it consisted of bags of cement, ¾ cu. ft. of sand, and ½ cu. ft. of broken stone, and was called a : ½ : mixture. it measured when mixed about ¾ cu. yd. the cement was furnished to the contractor by the railroad company, which undertook all the purchasing from the manufacturer, as well as the sampling, testing, and storing until the contractor needed it. the railroad company charged the contractor $ a barrel for this material. the sand was required by the specifications to be coarse, sharp, and silicious, and to contain not more than . % of mica, loam, dirt, or clay. all sand was carefully tested before being used. the stone was to be a sound trap or limestone, passing a ½-in. mesh and being retained on / -in. mesh. the contractor was allowed to use a coarser stone than this, namely, one that had passed a -in. and was retained on a ½-in. mesh. the concrete was to be machine-mixed, except in cases of local necessity. the quantity of water used in the mixture was to be such that the concrete would quake on being deposited, but the engineer was to use his discretion on this point. concrete was to be deposited in such a manner that the aggregates would not separate. it was to be laid in layers, not exceeding in. in thickness, and thoroughly rammed. when placing was suspended, a joint was to be formed in a manner satisfactory to the engineer. before depositing fresh concrete, the entire surface on which it was to be laid was to be cleaned, washed and brushed, and slushed over with neat cement grout. concrete which had begun to set was not to be used, and retempering was not to be allowed. [illustration: manhattan types fig. .] the forms were to be substantial and hold their shape until the concrete had set. the face forms were to be of matched and dressed planking, finished to true lines and surfaces; adequate measures were to be taken to prevent concrete from adhering to the forms. warped or distorted forms were to be replaced. plastering the face was not allowed. rock surfaces were to be thoroughly washed and cleaned before the concrete was deposited. these specifications were followed quite closely. a typical working gang, as divided among the various operations, is shown below: _superintendence._ ½ superintendent @ $ per month ½ assistant engineer " " " assistant superintendent " " " _surface transport._ foreman @ $ . per day engineer " . " " signalman " . " " laborers " . " " teams " . " " _laying._ foreman @ $ . per day laborers " . " " _forms._ foreman @ $ . per day carpenters " . " " helpers " . " " _tunnel transport._ ¼ foreman @ $ . per day ¼ engineer " . " " ¼ signalman " . " " laborers " . " " _mixers._ ¼ foreman @ $ . per day laborers " . " " the superintendent and assistant engineer looked after the brickwork and other work as well as the concrete. the surface transport gang handled all the materials on the surface, including the fetching of the cement from the cement warehouses. the tunnel transport gang handled all materials in the tunnel, but, when the haul became too long, the gang was reinforced with laborers from the laying gang. of the laying gang, two generally did the spading, two the spreading and tamping, and the remaining force dumped the concrete. the general cost of this part of the work is shown in table . the figures in table include the various items built into the concrete and some that are certificate extras in connection with the concrete, such as drains, ironwork and iron materials, rods and bars, expanded metal, doors, frames and fittings, etc. _water-proofing._--according to the specifications, the water-proofing was to consist of seven layers of pitch and six layers of felt on the side-walls and a ½-in. layer of mastic, composed of coal-tar and portland cement, to be plastered over the outside of the arches. by the time the work was in hand, some distrust had arisen as to the efficiency of this mastic coating, and a great deal of study was devoted to the problem of how to apply a felt and pitch water-proofing to the arches. the difficulty was that there was no room between the rock and the arch or between the timber and the arch (as the case might be) in which to work. several ingenious schemes of putting the felt on in layers, or in small pieces like shingles, were proposed and discussed, and a full-sized model of the tunnel arch was even built on which to try experiments, but it was finally decided to overcome the difficulty by leaving out the arch water-proofing altogether, and simply building in pipes for grouting through under pressure, in case it was found that the arch was wet. as to the arch built through the length excavated by cut-and-cover on the new york side, it was resolved to water-proof that with felt and pitch exactly as the side-walls were done, the spandrel filling between the arches being raised in a slight ridge along the concrete line between tunnels in order to throw the water over to the sides. the portions of arch not water-proofed were rather wet, and grouting with a : mixture was done, but only with the effect of stopping large local leaks and distributing a general dampness over the whole surface of the arch. table .--cost of concrete in land tunnels, in dollars per cubic yard. =======================================+==========+==========+========== | | | total |manhattan.|weehawken.| yardage. ---------------------------------------+----------+----------+---------- cubic yards placed | , ½ | , | , ½ ---------------------------------------+----------+----------+---------- labor. | average cost per cubic yard. ---------------------------------------+----------+----------+---------- surface transport | $ . | $ . | $ . superintendence and general labor at | | | point of work | . | . | . mixing | . | . | . laying | . | . | . tunnel transport | . | . | . cleaning | . | | . forms: erecting and removal | . | . | . ---------------------------------------+----------+----------+---------- total labor | $ . | $ . | $ . ---------------------------------------+----------+----------+---------- material. ---------------------------------------+----------+----------+---------- cement | $ . | $ . | $ . sand | . | . | . stone | . | . | . lumber for forms | . | . | . sundry tunnel supplies | . | . | . ---------------------------------------+----------+----------+---------- total materials | $ . | $ . | $ . ---------------------------------------+----------+----------+---------- plant running | $ . | $ . | $ . surface labor, repairs and maintenance | . | . | . field office administration | . | . | . ---------------------------------------+----------+----------+---------- total field charges | $ . | $ . | $ . ---------------------------------------+----------+----------+---------- plant depreciation | $ . | $ . | $ . chief office administration | . | . | . ---------------------------------------+----------+----------+---------- total average cost per cubic yard | $ . | $ . | $ . ---------------------------------------+----------+----------+---------- cost of miscellaneous items in concrete. ---------------------------------------+----------+----------+---------- |manhattan.|weehawken.| average. cubic yards | , ½ | , | , ½ amount, in dollars |$ , . | $ , . |$ , . unit cost | . | . | . =======================================+==========+==========+========== the -ft. -in. tunnel adjoining the terminal station-west was water-proofed by a surface-rendering method which, up to the present time, has been satisfactory. generally speaking, the arches of the land tunnels, though not dripping with water, are the dampest parts of the whole structure from tenth avenue to weehawken, and it would seem as if some form of water-proofing over these arches would have been a distinct advantage. there was no difficulty in applying the water-proofing on the side-walls, after a little experience had been gained as to the best methods. the specifications required the sand-wall to be covered with alternate layers of coal-tar pitch and felt, seven layers of the former and six layers of the latter, the felt to be of hydrex brand or other equally satisfactory to the engineer. the pitch was to be straight-run, coal-tar pitch which would soften at ° fahr., and melt at ° fahr., being a grade in which distillate oils, distilled from it, should have a specified gravity of . . the pitch was to be mopped on the surface to a uniform thickness of / in., and a covering of felt, previously mopped with pitch, was to be applied immediately. the sheets were to lap not less than in. on cross-joints and in. on longitudinal joints, and had to adhere firmly to the pitch-covered surface. this layer was then to be mopped, and another layer placed, and so on until all the layers were in place. this water-proofing was to extend from the bottom of the cable conduits to the springing of the brick arch. where sub-track conduits were used, these were to be surrounded with their own water-proofing. the work was carried out as specified; the sand-walls were not rendered, but were built smooth enough to apply the water-proofing directly to them. they were dried with gasoline torches before the application of the pitch, and in very wet sections grooves were cut to lead the water away. the first attempts were with the felt laid in horizontal strips. this ended very disastrously, as the pitch could not sustain the weight of the felt, and the whole arrangement slipped down the wall. the felt was then laid vertically, being tacked to a piece of horizontal scantling at the top of the sand-wall and also held by a row of planks braced against it at about half its height. a layer of porous brick was laid as a drain along the base of the water-proofing, covered by a single layer of felt to prevent it from becoming choked with concrete. the water-proofing of the sub-track conduits was troublesome, as the numerous layers and the necessity for preserving the proper laps in both directions between adjacent layers made the whole thing a kind of chinese puzzle. various modifications, to suit local conditions, were made from time to time. conduits outside the general outline of the tunnel are difficult to excavate, to lay, and to water-proof, and should be avoided wherever possible. the usual force in water-proofing consisted of a foreman, at $ . per day, and nine laborers at $ . per day. these men not only laid the water-proofing, but transported the materials, heated the pitch, and cut up the rolls of felt. in general, two men transported material, one tended the heater, and the other six worked in pairs, two preparing the surface of the concrete sand-wall, two laying pitch, and two laying felt. the cost of the water-proofing operation was about as shown in table . table .--cost of water-proofing, in dollars per square foot. =======================================+==========+===========+======== |manhattan.| weehawken.| total. ---------------------------------------+----------+-----------+-------- square feet covered | , | , | , ---------------------------------------+----------+-----------+-------- average cost per square foot. ---------------------------------------+----------+-----------+-------- labor | $ . | $ . | $ . material | . | . | . ---------------------------------------+----------+-----------+-------- total field charges | $ . | $ . | $ . chief office and plant depreciation | . | . | . ---------------------------------------+----------+-----------+-------- total average cost | $ . | $ . | $ . =======================================+==========+===========+======== _brickwork in arches._--owing to the heavy timbering, the brickwork at manhattan was interfered with to a considerable extent, and the gang was always kept at work at two or more places. the work was carried up to a point where it was necessary to back-fill, or prop or cut away encroaching timbers, and then the men were moved to another place while this was being done. the centers were set up in sets of seven, spaced ft. apart. two -ft. lengths of by -in. yellow pine lagging were used with each set of ribs, with by -in. block lagging in the crown. all centers were set ¼ in. high, to allow for settlement, except in the -ft. -in. span, in which they were set ½ in. high. this proved ample, the average settlement of the ribs being . ft. and of the masonry, . ft. in the -ft. -in. span the ribs were strengthened with by -in. blocking and by -in. posts to subgrade. great trouble was here encountered with encroaching timbering, due to the settlement of the wide flat span. grout pipes were built in, as previously mentioned. each mason laid an average of . cu. yd. of brickwork per hour, or . cu. yd. per day. the number of bricks laid per mason per hour was , or , per day. the bricks were of the best quality of vitrified paving brick, and were obtained from the jamestown brick company, of jamestown, n. y. the average size was ¾ by - / by - / in.; the average number per cubic yard of masonry was , the arches being from ft. to ft. in. in span and from to in. thick. the joints were / in. at the face and averaged / in. through the arch. the proportions for mortar were of cement and ½ of sand. one cubic yard of masonry was composed of . % brick and . % mortar. the volume of the ingredients in a four-bag batch was . cu. ft., and the resulting mixture was . cu. ft. the number of barrels of cement was . per cu. yd. of masonry, and about . % of the mortar made was wasted. the average force employed was: _laying._ foreman @ $ . per day layers " . " " tenders " . " " mixers " . " " _forms._ foreman @ $ . per day carpenters " . " " helpers " . " " _transport._ ¼ hoist engineer @ $ . per day ¼ signalman " . " " laborers " . " " for materials, the following prices prevailed: cement, $ . per bbl., sand, $ . to $ . per cu. yd., brick, $ . per thousand, delivered at yard, centers, $ . each, lagging, $ . per , ft. b. m. the cost of the brickwork is given in table . table .--cost of brickwork. ===========================================+==========+==========+====== |manhattan.|weehawken.|total. -------------------------------------------+----------+----------+------ cubic yards placed | , | | , -------------------------------------------+----------+----------+------ labor. |average cost per cubic yard. -------------------------------------------+----------+----------+------ surface transport | $ . | $ . | $ . superintendent and general labor at point | | | of work | . | . | . laying and mixing | . | . | . forms: erection and removal | . | . | . tunnel transport | . | . | . -------------------------------------------+----------+----------+------ total labor | $ . | $ . | $ . -------------------------------------------+----------+----------+------ material. -------------------------------------------+----------+----------+------ brick | $ . | $ . | $ . cement | . | . | . sand | . | . | . forms | . | . | . overhead conductor pockets | . | . | . -------------------------------------------+----------+----------+------ total material | $ . | $ . | $ . -------------------------------------------+----------+----------+------ plant running | $ . | $ . | $ . surface labor, repairs and maintenance | . | . | . field office administration | . | . | . -------------------------------------------+----------+----------+------ total field charges | $ . | $ . |$ . -------------------------------------------+----------+----------+------ chief office administration | $ . | $ . | $ . plant depreciation | . | . | . -------------------------------------------+----------+----------+------ total average cost per cubic yard | $ . | $ . |$ . ===========================================+==========+==========+====== in table the cost of grout is expressed in terms of barrels of cement used, because in the schedule of prices attached to the contract, that was the unit of payment for grout. table .--cost of grout over arches in land tunnels. cost, in dollars per barrel of cement used. ======================================+===============+==========+====== | manhattan. | | |(gy-east only.)|weehawken.|total. --------------------------------------+---------------+----------+------ barrels used | , ½ | ½ | , --------------------------------------+---------------+----------+------ average cost per barrel of cement used. --------------------------------------+---------------+----------+------ labor | $ . | $ . |$ . material | . | . | . field office administration | . | . | . plant and supplies | . | . | . --------------------------------------+---------------+----------+------ total field charges | $ . | $ . |$ . --------------------------------------+---------------+----------+------ chief office and plant depreciation | . | . | . --------------------------------------+---------------+----------+------ total average cost | $ . | $ . |$ . ======================================+===============+==========+====== _vitrified earthenware conduits for electric cables._--the general drawings will show how the ducts were arranged, and that manholes were provided at intervals. they were water-proofed, in the case of those embedded in the bench, by the general water-proofing of the tunnels, which was carried down to the level of the bottom of the banks of ducts; and in the case of those below subgrade, by a special water-proofing of felt and pitch wrapped around the ducts themselves. the portion of wall in front of the ducts was bonded to that behind by bonds, mostly of expanded metal, passing between the ducts. examples of the bonding will be seen in the drawings. the joints between successive lengths of -way and -way ducts were wrapped with two thicknesses of cotton duck, in. wide, those of single-way ducts were not wrapped, but plastered with cement mortar. the ducts were laid on beds of mortar, and were made to break joints at top and bottom and side to side with the adjacent ducts. they were laid with a wooden mandrel; a square leather washer at the near end acted as a cleanser when the mandrel was pulled through. the specifications required the ducts to be laid at the same time as the concrete and be carried up with it, but this was found to be a very awkward operation, as the tamping of the concrete and the walking of men disturbed the ducts, especially as the bonds lay across them. it was resolved, therefore, to build the portion of the wall behind the ducts first, with the bonds embedded in it at the proper heights and projecting from it, then to lay up the banks of ducts against this wall, bending the bonds down as they were reached, and finally, after all the ducts were in, to lay the concrete in front of and over the top of the ducts. several detailed modifications of this general scheme were followed at one time or another when necessary or advisable. the laying of ducts below subgrade was not complicated by the presence of bonds, the water-proofing caused the trouble here, as before described. the specifications called for a final rodding after completion. a group of the apparatus used in this process is shown in fig. , plate xxxv; the various parts are identified by the following key: key to fig. , plate xxxv. .-- -way duct, for telephone and telegraph cables, .-- -way duct, for telephone and telegraph cables, .-- -way duct, for high- and low-tension cables, .--plug for closing open ends of ducts, .--plug for closing open ends of ducts in position, , , and .--cutters for removing obstructions, .--hedgehog cutter for removing grout in ducts, .--rodding mandrel for multiple ducts, .--laying mandrel, .--rodding mandrel, with jar-link attached, .--laying mandrel, and .--rubber-disk cleaners, used after final rodding, and .--sectional wooden rods used for rodding, .--section of iron rods used for rodding, .--jar-link, .--cotton duck for wrapping joints of multiple ducts, .--hook for pulling forward laying mandrel, .--top view of trap for recovering lost or broken rods left in ducts. [illustration: plate xxxv. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. . fig. .] ordinary ¾-in. gas pipe was used for the rod, and a cutter with rectangular cross-section and rounded corners was run through ahead of the mandrel: following the cutter came a scraper consisting of several square leather washers, of the size of the ducts, spaced at intervals on a short rod. the mandrel itself was next put through, three or four men being used on the rods. all the ducts in a bank were thus rodded from manhole to manhole. when a duct was rodded it was plugged at each end with a wooden plug. a solid wooden paraffined plug was used at first, but afterward an expansion plug was used. very little trouble was met in rodding the power conduits, except for a few misplaced ducts, or a small mound of mortar or a laying mandrel left in. at such points a cut was made in the concrete and the duct replaced. in the subgrade telephone and telegraph ducts east of the manhattan shaft, much trouble was caused by grout in the ducts. the mandrel and cutters were deflected and broke through the web of the ducts rather than remove this hard grout. trenches had to be cut from the floor to the top of the water-proofing, the latter was then cut and folded back, and the ducts replaced. to do this, a number of ducts had to be taken out to replace the broken ones and get the proper laps. the water-proofing was then patched and the concrete replaced. this grout had not penetrated the water-proofing, but had got in through the ends of the ducts where they had not been properly plugged and protected. the duct gang, both for laying and rodding, generally consisted of foreman, at $ . per day, and laborers, at $ . per day. when laying: men were laying, men mixing and carrying mortar, and were transporting material. when rodding: men were rodding, men at adjacent manholes were connecting and disconnecting cutters and mandrels, was joining up rods, and men assisting generally. the cost of this work is shown in table . transportation and disposal. the track on the surface and in the tunnels was of -lb. rails on a -ft. gauge. the excavation was handled in scale-boxes carried on flat cars, and the concrete in ¼-cu. yd. mining cars dumping either at the side or end. table .--cost of conduit work. =========================================+==========+==========+======= |manhattan.|weehawken.| total. -----------------------------------------+----------+----------+------- duct feet | , | , | , -----------------------------------------+----------+----------+------- average cost per duct foot. -----------------------------------------+----------+----------+------- labor | $ . | $ . | $ . material | . | . | . -----------------------------------------+----------+----------+------- total field charges | . | . | . -----------------------------------------+----------+----------+------- chief office and plant depreciation | . | . | . -----------------------------------------+----------+----------+------- total average cost | $ . | $ . | $ . =========================================+==========+==========+======= when the haulage was up grade, by -in. lidgerwood hoisting engines, with -in. single friction drums, and driven by compressed air from the high-pressure lines, were used. down grade, cars were moved and controlled by hand. the muck which came through the shaft at manhattan was dumped into hopper bins on the surface and thence loaded into trucks at convenience. at the open cut, the muck was dumped into trucks direct. the trucking was sublet by the contractor to a sub-contractor, who provided trucks, teams, and trimmers at the pier. at weehawken, arrangements were made with the erie railroad which undertook to take muck which was needed as fill. the tunnel cars, therefore, were dumped directly on flat cars which were brought up to a roughly made platform near the shaft. the hoisting at manhattan was by derrick at tenth avenue and the open cut, and by the elevator at the manhattan shaft. at weehawken, all hoisting was done by the elevator in the shaft. the sand and stone were received at the wharves by scows. at manhattan, these materials were unloaded on trucks by an overhead traveler, and teamed to the shaft, where they were unloaded by derricks into the bins. at weehawken, they were unloaded by an orange-peel grab bucket, loaded into cars on the overhead trestle, transported in these to the top of the shaft, and discharged into the bins. the cement at manhattan was trucked from the company's warehouse, at eleventh avenue and th street, to the shaft, where it was put into a supplementary storage shed at the top of the shaft, whence it was removed to the mixer by the elevator when needed. at weehawken, it was taken on flat cars directly from the warehouse to the mixer. lighting. temporarily and for a short time at the start, kerosene flares were used for light until replaced by electric lights, the current for which was furnished by the contractor's generators, which have been described under the head of "power plant." the lamps used along the track were of c.p., and were protected by wire screens; these were single, but, wherever work was going on, groups of four or five, provided with reflectors, were used. pumping. two pumps were installed at the manhattan shaft. they had to handle the water, not only from the rock tunnels, but also from those under the river. one was a deane compound duplex pump, having a capacity of gal. per min., the other, a blake pump, of gal. per min. they were first driven by steam direct from the power-house, but compressed air was used later. when the power-house was shut down, an electrically-driven centrifugal pump was used. this was driven by a general electric shunt-wound motor, type c- ½, with a speed of , rev. per min. at volts and . amperes ( h.p.) when open, and . amperes ( h.p.) when closed, and had a capacity of gal. per min. to send the water to the shaft sump during the construction, small compressed-air cameron pumps, of about gal. per min., were used. at the weehawken shaft two pumps were used; these dealt with the water from the bergen hill tunnels as well as that from the weehawken tunnels. at first a worthington duplex pump having a capacity of about gal. per min. was used. later, this was replaced by a general electric shunt-wound motor, type o- , with a speed of rev. per min. at volts and amperes ( h.p.) when open, and . amperes ( h.p.) when closed. its capacity was gal. per min. during the progress of the construction, the water was pumped from the working face to the shaft by small cameron pumps similar to those used at manhattan. when the work was finished, a subgrade reversed-grade drain carried the water to the shaft sump by gravity. the work in the manhattan land tunnels was practically finished by may st, , though the ventilating arrangements and overhead platform in the intercepting arch were not put in until after the river tunnel concrete was completed, so that the work was not finished until september, . the weehawken land tunnels work was finished in july, , but the benches and ventilating arrangements in the weehawken shaft were not put in until after the completion of the bergen hill tunnels, and so were not finished until august, . the reinforced concrete wall around the weehawken shaft, together with the stairs from the bench level of the shaft to the surface, was let as a separate contract; the work was started on september th, , and finished by the end of december, . river tunnels. the river tunnel work, from some points of view, has the most interest. it is interesting because it is the first main line crossing of the formidable obstacle of the hudson river, and also by reason of the long and anxiously discussed point as to whether, in view of the preceding experiences and failures to construct tunnels under that river, foundations were needed under these tunnels to keep them from changing in elevation under the action of heavy traffic. the river tunnels here described start on the east side of the shield chambers on the new york side and end at the east side of the shield chambers on the new jersey side. they thus include the new york and exclude the new jersey shield chambers, the reason for such discrimination being that the new york shield chambers are lined with cast iron while those on the new jersey side are of the typical rock section type, as already described. the design of the tunnels and their accessories will be first described, then will come the construction of the tunnels as far as the completion of the metal lining, followed by a description of the concrete lining and completion of the work. design of metal lining. _new york shield chambers._--the shield chambers may be seen on plate xxxii, previously referred to, which shows the junction of the iron-lined tunnels and the shield chambers. they consist of two iron-lined pieces of tunnel placed side by side, with semi-circular arches and straight side-walls. the segments of the arch are made to break joint with one another by making the side-wall or column castings of two different heights, as shown in fig. . the length of each ring is in. the reason for the adoption of this type of construction was the necessity for keeping the width of the permanent structure within the -ft. width of the street. the length of this twin structure is . ft., and the weight of the metal in it is as follows: long-column arch rings at , lb. , lb. short-column arch rings at , lb. , " ------- total weight , lb. _general type of river tunnel lining._--the main ruling type adopted for the tunnels under the hudson river, and in the soft water-bearing ground for some distance on the shoreward side of the river lines, consists of two parallel metal-lined tunnels, circular in cross-section, each tunnel being ft. outside diameter, and the two tunnels ft. apart from center to center, as shown on fig. . the metal lining is of cast iron (except for a few short lengths of cast steel) and of the usual segmental type, consisting of "rings" of iron, each ring being ft. in. in length, and divided by radial joints into eleven segments, or "plates," with one "key," or closing segment, having joints not radial but narrower at the outside circumference of the metal lining than at the inside. the whole structure is joined, segment to segment, and ring to ring, by mild-steel bolts passing through bolt holes in flanges of all four faces of each segment. the joints between the segments are made water-tight by a caulking of sal-ammoniac and iron borings driven into grooves formed for the purpose on the inner edges of the flanges. the clearances between the bolts and the bolt holes are also made water-tight by using grummets or rings of yarn smeared with red lead, having a snug fit over the shank of the bolt and placed below the washer on either end of each bolt. when passing through ground more or less self-sustaining, the space outside the iron lining (formed by the excavation being necessarily rather larger than the external diameter of the lining itself) was filled with grout of : portland cement and sand forced by air pressure through grout holes in each segment. these holes were tapped, and were closed with a screw plug before and after grouting. [illustration: details of manhattan shield chambers fig. .] having thus stated in a general way the main ruling features of the design, a detailed description of the various modifications of the ruling type will be given. [illustration: typical cross-section of ruling design of metal-lined shield-driven tunnels fig. .] the two main divisions of the iron lining are the "ordinary" or lighter type and the heavy type. the details of the ordinary iron are shown in fig. , which shows all types of lining. it was on this design that the contract was let, and it was originally intended that this should be the only type of iron used. the dimensions of the iron are clearly shown on the drawing, and it will be seen that the external diameter is ft., the interior diameter, ft. in., the length of each ring, ft. in., and the thickness of the iron skin or web, ½ in. the bolt holes in the circumferential flanges are evenly spaced through the circle, so that adjacent rings may be bolted together in any relative position as regards the radial joints, and, as a matter of fact, in the erection of the tunnel lining, all the rings "break joint," with the exception of those at the bore segments, as will be described later. this type of iron, when the original type was modified, came to be known as the ordinary pocketless iron; that is, the weight is of the ordinary or lighter type, in contradistinction to the heavier one, which later supplanted it, and the caulking groove runs along the edges of the flanges and does not form pockets around the bolt holes, as did the groove in a later type. each ring is made up of eleven segments and a key piece. of these, nine have radial joints at both ends, and are called "_a_" segments; two, called "_b_" segments, have a radial joint at one end and a non-radial joint at the other. the non-radial joint is placed next to the key, which is . in. wide at the outside circumference of the iron and . in. wide at the inside. the web is not of uniform thickness. the middle part of each _a_ and _b_ segment is ½ in. thick; at the distance of in. from the root of each flange, the thickness of web begins to increase, so that at the root it is - / in. thick. the web of the key plate is ¾ in. thick. the bolts are of mild steel, and are ½ in. in diameter; there are in one circumferential joint and in each radial joint. as there are such radial joints, there are altogether bolts in the cross-joints, making a total of bolts per ring. this original type of ordinary iron was modified for a special purpose as follows: it was known that for some distance on either side of the river, and especially at weehawken, the tunnels would pass through a gravel formation, rather open, and containing a heavy head of water. it was thought that, by carrying the caulking groove around the bolt holes, it would be possible to make them more water-proof than by the simple use of the red-leaded grummets. hence the "pocket iron" was adopted for this situation, the name being derived from the pocket-like recess which the caulking groove formed when extended around the bolt hole. the details of this lining are shown on fig. , and the iron (except for the pockets) is exactly like the pocketless type. [illustration: details of all types of metal linings used in subaqueous shield-driven tunnels fig. .] on the new york side, in both north and south tunnels, two short lengths were built with cast-steel lining. this was done where unusual stresses were expected to come on the lining, namely, at the point where the invert passed from firm ground to soft, and also where the tunnels passed under the heavy river bulkhead wall. the design was precisely the same as for the ordinary pocketless iron, and fig. shows the details. after the tunnels had entered into the actual under-river portion, several phenomena (which will be described later) led to the fear that the tunnels, being lighter than the semi-liquid mud they displaced, might be subject to a buoyant action, and therefore a heavier type of lining was designed. the length of ring, number of bolts, etc., were just the same as for the lighter iron, but the thickness of the web was increased from ½ to in., the thickness of the flanges was proportionately increased, and the diameter of the bolts was increased from ½ to ¾ in. this iron was all of the pocketless type, shown in fig. . table gives the weights of the various types of lining. table .--weights of tunnel lining, diameter and weights of bolts, etc. +=========+===============+========+========+=======+========+========| |reference|type of lining.| weight | weight |weight | weight |diameter| |no. | | of one | of one |of one | of one | of | | | | "a" | "b" |key, in|complete| bolts, | | | |segment,|segment,|pounds.|ring, in| in | | | | in | in | |pounds. |inches. | | | |pounds. |pounds. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |---------+---------------+--------+--------+-------+--------+--------| | |ordinary cast | , | , | | , | ½ | | |iron without | | | | | | | |caulking | | | | | | | |pockets. | | | | | | | |ordinary cast | , | , | | , | ½ | | |iron with | | | | | | | |caulking | | | | | | | |pockets. | | | | | | | |ordinary cast | , | , | | , | ½ | | |steel without | | | | | | | |caulking | | | | | | | |pockets. | | | | | | | |heavy cast iron| , | , | | , | ¾ | | |without | | | | | | | |caulking | | | | | | | |pockets. | | | | | | +---------+---------------+--------+--------+-------+--------+--------+ +=========+===============+========+=======+=========+ |reference|type of lining.| weight |weight | total | |no. | | of | of |weight of| | | | bolt, |bolts, |one ring | | | |nut, and| nuts, |(segments| | | | | and | and | | | |washers,|washers| bolts), | | | | in | per | in | | | |pounds. | ring, | pounds. | | | | | in | | | | | |pounds.| | |---------+---------------+--------+-------+---------| | |ordinary cast | . | . | , | | |iron without | | | | | |caulking | | | | | |pockets. | | | | | |ordinary cast | . | . | , | | |iron with | | | | | |caulking | | | | | |pockets. | | | | | |ordinary cast | . | . | , | | |steel without | | | | | |caulking | | | | | |pockets. | | | | | |heavy cast iron| . | , . | , | | |without | | | | | |caulking | | | | | |pockets. | | | | +---------+---------------+--------+-------+---------+ weights of various types of lining per linear foot of tunnel. +---------+---------------+--------------+-------------+---------------+ |reference|type of lining.|weights of |weights of |weights of | |no. | |complete rings|bolts, nuts, |segments and | | | |(segments |and washers, |bolts in tunnel| | | |only), in |in pounds. |complete, in | | | |pounds. | |pounds. | |---------+---------------+--------------+-------------+---------------| | |ordinary cast | , . | . | , . | | |iron without | | | | | |pockets. | | | | | | | | | | | |ordinary cast | , . | . | , . | | |iron with | | | | | |pockets. | | | | | | | | | | | |ordinary cast | , . | . | , . | | |steel without | | | | | |pockets. | | | | | | | | | | | |heavy cast iron| , . | . | , . | | |without | | | | | |pockets. | | | | +=========+===============+==============+=============+===============+ the weights in table are calculated by assuming cast iron to weigh lb. per cu. ft., and cast steel lb. in actual practice the "ordinary" iron was found to weigh a little more than the weights given, and the "heavy" a little less. the silt in the sub-river portion averaged about lb. per cu. ft., so that the weight of the silt displaced by the tunnel was about , lb. per lin. ft. _taper rings._--in order to pass around curves (whether horizontal or vertical), or to correct deviation from line or grade, taper rings were used; by this is meant rings which when in place in the tunnels were wider than the standard rings, either at one side (horizontal tapers or "liners"), or at the top ("depressors"), or at the bottom ("elevators"). in the original design a ½-in. taper was called for, that is, the wide side of the ring was ½ in. wider than the narrow side, which was of the standard width of ft. in. as a matter of fact, during construction, not only ½-in., but ¾-in. and -in. tapers were often used. these taper rings necessitated each plate having its own unalterable position in the ring, hence each plate of the taper ring was numbered, so that no mistake could be made during erection. the taper rings were made by casting a ring with one circumferential flange much thicker than usual, and then machining off this flange to the taper. this was not only much cheaper than making a special pattern for each plate, but made it possible to see clearly where and what tapers were used in the tunnel. taper rings were provided for all kinds of lining (except the cast steel), and the lack of taper steel rings was felt when building the steel-lined parts of the tunnel, as nothing could be done to remedy deviations from line or grade until the steel section was over and cast iron could again be used. table gives the weights of the different kinds of tapers used. table .--weights of cast-iron taper rings, in pounds per complete ring. =================================+====================================== classification. |weight of cast iron per complete ring, | in pounds. ---------------------------------+-------------------------------------- ordinary pocketless ½- in. taper| , . " " - " " | , . " pocket ½- " " | , . heavy pocketless ½- in. taper | , . " " ¾- " " | , . " " - " " | , . =================================+======================================= _cast-steel bore segments and accessories._--the following feature of these tunnels is different from any hitherto built. it was the original intention to carry the rolling load independent of the tunnel, or to assist the support of the silt portion of the structure by a single row of screw-piles, under each tunnel, and extending down to firmer ground than that through which the tunnels were driven. therefore, provision had to be made whereby these piles could be put down through the invert of the tunnel with no exposure of the ground. [illustration: details of bore segments and accessories used in subaqueous shield driven tunnels fig. .] this provision was afforded by the "bore segments," which are shown in detail in fig. . there are two segments, called no. and no. , respectively. these two segments are bolted together in the bottom of two adjacent rings, and thus form a "pile bore." as the piles were to be kept at -ft. centers, and as the tunnel rings were ft. in. in length, it will be seen that, between each pair of bore-segment rings, there came four "plain" rings. the plain rings were built up so that the radial joints broke joint from ring to ring, but with the bore-segment rings this could not be done, without unnecessarily adding to the types of segments. the bore segments were made of cast steel, and were quite complicated castings, the principle, however, was quite simple. the segments provided an opening just a little larger than the shaft of the pile, the orifice being ft. in. in diameter at the smallest (lowest) point, while the shaft of the pile was to be ft. ¼ in. in order to allow of the entry of the screw-blade or helix of the pile, a slot was formed in the depth of bore segment no. , so that, when a pile was put in position above the bore, the blade, when revolved, would enter the slot and thus pass under the metal lining, although the actual orifice was only slightly larger than the pile shaft. the wall of the pile orifice in segment no. was made lower than that in no. so as to allow the blade to enter the slot in segment no. . when the pile is not actually in process of being sunk, this lower height in no. is made up with the removable "distance piece." this had a tongue at one end which engaged in a recess cast to take it in segment no. and was held in place by a key piece at the other end of the distance piece. details of the distance piece and key are shown in fig. . the flanges around the pile bore were made flat and furnished with twelve tapped holes, six in segment no. and six in segment no. , for the purpose of attaching the permanent arrangements in conjunction with which the pile was to be attached to the track system, independently of the tunnel shell, or directly to the tunnel. it was never decided which of these alternatives would be used, for, before this decision was reached, it was agreed that, at any rate for the present, it was better not to put down piles at all. to close the bore, the "bore plug" was used. this is shown on fig. . it was of cast steel, and was intended to act as a permanent point of the screw-pile, that is, the blade section was to be attached to the bore plug, the distance piece and key were to be removed, and the pile was to be rotated until the blade had cleared the slot; the distance piece and key were then to be replaced and sinking resumed. the plug was held in place against the pressure of the silt by the two "dogs," while the dogs themselves were attached to the tunnel, as shown in fig. . the ends of the dogs, which rested on the flanges of the metal lining of the tunnel, were prevented from being knocked off the flanges (and thus releasing the plug) by steel clips. it was expected that it might be desirable to keep the lower end of the piles open during their sinking, so that the bore plugs were not made permanently closed, but a seating was formed on the inner circumference of the plug, and on the seating was placed the "plug cover," made of cast iron, ¾ in. in diameter and in. thick, furnished with a lug for lifting and a -in. tapped hole closed by a screw-plug, through which any soundings or samples of ground could be taken prior to sinking the piles. this plug cover was held in place by a heavy steel "yoke" under it, which engaged on the under side of the flange, on top of which the cover was set. the yoke was attached to the cover by a ¾-in. tap-bolt, screwed into the yoke and passing through a -in. hole bored in the center of the cover. this rather peculiar mode of attaching the cover was adopted so that the cover could be removed by taking off the nut of the yoke, in case it was desired to open the end of the pile during the process of sinking. the plug was a fairly close fit at the bottom of the orifice, that is, at the outside circumference of the tunnel, where the bore was ft. in. in diameter and the plug ft. ¾ in., but at the top of the bore-segment there was more clearance, as the plug was cylindrical while the bore tapered outward. to fill this space, it was intended that steel wedges should be used while the shield was being driven, so that they would withstand the crushing action of the thrusting shield, and, when the shield was far enough ahead, that they should be removed and replaced by hardwood wedges. this method was only used in the early weeks of the work; the modification of not using the shield-jacks which thrust against the bore segments was then introduced, and the wooden wedges were put in, when the bore plugs were set in place, and driven down to the stage of splitting. when it was resolved not to sink the screw-piles, the bores had to be closed before putting in the concrete lining. this was done by means of the covers shown in fig. . the bore plug and all its attachments were removed, and the flat steel cover, in. thick and with stiffening webs on the under side, was placed over the circular flanges of the pile bore. the cover was attached to the bore segments by twelve ½-in. stud-bolts, in. long, in the bolt holes already mentioned as provided on these flanges. when these were in place, with lead grummets under the heads of the bolts, and the grooves caulked, the bore segments were water-tight, except in bore segment no. , at the joint of the distance piece; and, to keep water from entering here, this segment was filled to the level of the top of the flanges with : portland cement mortar. [illustration: subaqueous tunnels cover for bore segments fig. .] the weights of the various parts of the bore segments are given in table . table .--weights of bore segments and accessories, in pounds. ====================+=====+==================================== part. | no. | material. | weight, in pounds. --------------------+-----+---------------+-------------------- bore segment no. | | cast steel | , . bore segment no. | | " " | , . distance piece | | " " | . key | | " " | . plug | | " " | , . yoke | | " " | . dogs | | " " | . slot cover | | rolled steel | . plug cover | | cast iron | . dog holders | | rolled steel | . --------------------+-----+---------------+-------------------- complete weight of one pair, without bolts| , . ==========================================+==================== _sump segments._--in order to provide sumps to collect the drainage and leakage water in the subaqueous tunnels, special "sump segments" were installed in each tunnel at the lowest point--about station + . the details of the design are shown in fig. . the segment was built into the tunnel invert as though it were an ordinary "_a_" segment. in building the sump, three lining castings were bolted, one on top of the other, and attached to the flat upper surface of the sump segment; meanwhile, the bolts attaching the sump segment to the adjacent tunnel plates were taken out and the plate and lining segments were forced through the soft mud by hydraulic jacks, the three -in. holes in the bottom of the sump segment being opened in order to minimize the resistance. the sump when built appeared as shown in fig. , the top connection being made with a special casting, as shown. the capacity of each sump is gal., which is about the quantity of water entering the whole length of each subaqueous tunnel in hours. _cross-passages._--when the contract was let, provision was made for cross-passages between the tubular tunnels, in the form of special castings to be built into the tunnel lining at intervals. however, the idea was given up, and these castings were not made. later, however, after tunnel building had started, the question was raised again, and it was thought that such cross-connections would be very useful to the maintenance forces, that it might be possible to build them safely, and that their subsequent construction would be made much easier if some provision were made for them while the shields were being driven. it was therefore arranged to build, at intervals of about ft., two consecutive rings in each tunnel, at the same station in each tunnel, with their longitudinal flanges together, instead of breaking joint, as was usually done. the keys of these rings were displaced twelve bolt holes from their normal positions toward the other tunnel. this brought the keys about ft. above the bench, so that if they were removed, together with the _b_ plates below them, an opening of about by ft. would be left in a convenient position with regard to the bench. [illustration: details of sumps in subaqueous tunnels at station fig. .] nothing more was done until after the tunnels were driven. it was then decided to limit the cross-passages between the tubular tunnels to the landward side of the bulkhead walls. they were arranged as follows: three on the new york side, at stations + , + , and + , and two on the new jersey side, at stations + and + . the cross-passages are square in cross-section. table .--weights of sump segments. ====================+=====+===============+==================== part. | no. | material. | weight, in pounds. --------------------+-----+---------------+-------------------- middle top casting | | cast steel | end top castings | | " " | , lining castings | | " " | , sump segment | | cast iron | , --------------------+-----+---------------+-------------------- total weight per sump, exclusive of bolts | , ==========================================+==================== _turnbuckle reinforcement for cast-iron segments._--during the period of construction, a certain number of cast-iron segments, mostly in the roof, but in some cases at manhattan in the invert, behind the river lines, became cracked owing to uneven pressures of the ground. before the concrete lining was put in, considerable discussion occurred as to the wisest course to pursue with regard to these broken plates. it was finally thought best not to take the plates out, as more harm than good might be done, but to reinforce them with turnbuckles, as shown in fig. . the number of broken segments was distributed as follows: north manhattan tunnel , chiefly in silt (not under the river), south manhattan tunnel , chiefly in silt ( " " " " ), north weehawken tunnel , chiefly in sand ( " " " " ), south weehawken tunnel , chiefly in silt, under the fowler warehouse. the chief features of the tunnel lining have now been described, and, before giving any account of the methods of work, it will be well to mention briefly the salient features of the concrete lining which is placed within the actual lining. design of concrete lining. this concrete lining will be considered and described in the following order: the new york shield chambers, standard cross-section of concrete lining of shield-driven tunnels, final lines and grades, and how obtained, steel rod reinforcement of concrete, cross-passage lining, special provision for surveys and observations. [illustration: subaqueous tunnels turnbuckles and rods reinforcing tunnel segments fig. .] _the new york shield chambers._--the cross-section of the concrete lining of these chambers is shown by plate xxxii, referred to in the land tunnel section. they are of the twin-tunnel double-bench type. the deep space beneath the floor is used as a sump for drainage, and manholes for access to the cable conduits are placed in the benches. [illustration: types of concrete lining of shield-driven tunnels. fig. .] _standard cross-section of concrete lining of shield-driven tunnels._--the cross-section of the concrete lining of the tube tunnel is shown in fig. . there are two main types, one extending from the shield chambers to the first bore segment, that is, to where the tunnel leaves solid ground and passes into silt, and the other which extends the rest of the way. the first type has a drain in the invert, the second has not. the height from the top of the rail to the soffit of the arch being less than ft. in., overhead pockets for the suspension of electrical conductors were set in the concrete arch on the vertical axis line at -ft. centers. these pockets are shown in fig. . the benches are utilized for the cable conduits in the usual way. ladders are provided on one side at -ft. and on the other side at -ft. intervals, to give access from the track level to the top of the benches. refuge niches for trackmen are placed at -ft. intervals on the single-way conduits side only, as there is not enough room in front of the -way ducts. manholes for giving access to the cable conduits, both power, and telephone and telegraph, are at -ft. intervals. _final lines and grades, and how obtained._--it may be well to explain here how the final lines and grades for the track, and therefore for the concrete lining, were obtained and determined. it is first to be premised that the standard cross-section of the tunnel (that is, of the concrete and iron lining combined) is not maintained throughout the tunnel. in other words, the metal lining is of course uniform, or practically so, throughout; the interior surface of the concrete lining is also uniform from end to end, but the metal lining, owing to the difficulty of keeping the shields, and hence the tunnels built within them, exactly on the true line and grade, is not on such lines and grades; the concrete lining is built exactly on the pre-arranged lines and grades, consequently, the relative positions of the concrete and metal linings vary continually along the length of the structure, according to whether the metal lining is higher or lower than it should be, further to the north or to the south, or any combination of these. as before stated, it was strongly desired to encroach as little as possible on the standard -ft. concrete arch, and after some discussion it was decided that a thickness of ft. in. was the thinnest it was advisable to allow. this made it possible to permit the metal lining of the tunnel to be in. lower, in respect to the level of the track at any point, than the standard section shows, and also allowed the center line of the track to have an eccentricity of in. either north or south of the center line of the tunnel. this only left to be settled the extent to which the metal lining might be higher in respect to the track than that shown on the standard section. this amount was governed by the desirability of keeping sufficient clearance between the top of the rail and the iron lining in the invert to admit of the attachment of pile foundations and all the accompanying girder-track system which would necessarily be caused by the use of piles, should it ever become apparent after operation was begun, that, after all, it was essential to have the tunnels supported in this way. careful studies were made of the clearance necessary, and it was decided that ft. in. was the minimum allowable depth from the top of the rail to the outside of the iron at the bottom. this meant that the iron lining could be in. higher, with respect to the track level, than that shown on the standard section. all the determining factors for fixing the best possible lines and grades for the track within the completed metal lining were now at hand. in march, , careful surveys of plan and elevation were made of the tunnels at intervals of ft. throughout. the following operations were then performed to fix on the best lines and grades: first, for line: it has been explained that the permissible deviation of the center line of the track on either side of the center line of the tunnel was in. had the metal lining been invariably of the true diameter, it would have been necessary to survey only one side of the tunnel; this would have given a line parallel to the center line, and might have been plotted as such; then, by setting off in. on either side of this line, there would have been obtained a pair of parallel lines within which the center line of the track must lie. owing to variations in the diameter of the tunnel, however, such a method was not permissible, and therefore the following process was used: when running the survey lines through the tunnel (which were the center lines used in driving the shields), offsets were taken to the inner edges of the flanges of the metal lining, both on the north and south sides, at axis level at each -ft. interval. on the plat on which the survey lines were laid down, and at each point surveyed, a distance was laid off to north and south equal to the following distances: offset, as measured in the tunnel to north (or south), minus . ft. this . ft. (or ft, in.) represents ft. in., the true radius to inside of iron, minus in., the permissible lateral deviation of the track from the axis of the tunnel. the result of this process was two lines, one on either side of the survey lines, not parallel to it or to each other, but approaching each other when the horizontal diameter was less than the true diameter, receding from each other when the diameter was more, and exactly in. apart when the diameter was correct. as long as the center line of the track lay entirely within these two limiting lines, the condition that the concrete arch should not be in. less in thickness than the standard ft. was satisfied, and in order to arrive at the final line, the longest possible tangents that would be within these limits were adopted as the final lines; and, as the survey lines were those used in driving the tunnel shields (that is, the lines to which it was intended that the track should be built), the amount by which the new lines thus obtained deviated from the survey lines was a measure of the deviation of the finally adopted track and concrete line from the original contract lines. next, for grades: the considerations for grade were very similar to those for line. if the vertical diameter of the tunnel had been true at each -ft. interval surveyed, it would have been correct to plot the elevations of the crown (or invert) as a longitudinal section of the tunnel, and to have set up over those points others in. above (as the metal lining could have been in. lower than the standard section, which is equivalent to the track being an equal amount higher), and below these crown or invert elevations others in. lower (as the metal lining could be in. higher). then, by joining the points in. above in one line and those in. below in another, there would have been obtained lines of limitation between which the track grades must lie. however, as the tunnel diameter was not uniformly correct, a modification of this method had to be made, as in the case of the line determination, the principle, however, remaining the same. the elevations were taken on the inner edges of the circumferential flanges of the metal lining, not only in the bottom, but also in the top, of the tunnel, at each -ft. interval; then, for the upper limit of the track at each such interval the following was plotted: elevation of inner edge of flange at top, minus . ft. this . ft. (or ft. in.) was obtained thus: the standard height from the top of the rail to the inner edge of the iron flange is ft. in., but, as the track may be in. above the standard or normal, the minimum height permissible is ft. in. for the lower limit of track at each -ft. interval the following was plotted: elevation of inner edge of flange at bottom, plus . ft. this . ft. (or ft. in.) was obtained thus: the standard height from the top of the rail to the inner edge of the iron flange is ft. in. ( ft. to outside of iron, less in. for depth of flange), but, as the track may be in. below the standard, the minimum height permissible is ft, in. less in., or ft. in. by plotting the elevations thus obtained, two lines were obtained which were not parallel but were closer together or further apart according as the actual vertical diameter was less or greater than the standard, and the track grade had to lie within these two lines in order to comply with the requirements indicated above. the results of these operations for the north tunnel are shown on plate xxxvi. the greatest deviations between the lines and grades in the subaqueous tunnels as determined by these means and those as originally laid out in the contract drawings are on the weehawken side, and were caused by the unexpected behavior of the tunnel when the shields were driven "blind" into the silt, causing a rise which could not be overcome, and the thrusting aside of one tunnel by the passage of the neighboring one. had this unfortunate incident not occurred, it is clear that it would have been possible to adhere very closely indeed to the contract lines and grades, although the deviation is small, considering all things. the internal outline of the concrete cross-section is uniform throughout, and is built on the lines and grades thus described. _steel rod reinforcement of concrete._--the original intention had been to line the metal lining of the tube tunnels with plain concrete, but, as the discussion on the foundation question continued, it was felt advisable, while still it was intended to put in the foundations, to guard against any stresses which were likely to come on the structure, by using a system of steel rods embedded circumferentially within the concrete. designs were made on this basis, and even the necessary material prepared, before the decision to omit the piles altogether was reached. however, in order to provide a safeguard for the structure where it is partly or wholly beyond the solid rock, it was decided to use reinforcement, even with the piles omitted. for this purpose the tunnel was considered as a girder, and longitudinal reinforcement was provided at the top and bottom. the top reinforcement extends from a point ft. behind the point where the crown of the tunnel passes out of rock on the new york side to where the crown passes into rock on the new jersey side. the bottom reinforcement extends from where the invert of the tunnel passes out of rock on the new york side to where it passes into rock on the new jersey side. the reinforcement both at top and bottom consists of twenty -in. square twisted rods, ten placed symmetrically on either side of the vertical axis, in. apart from center to center and set in. (to their centers) back from the face of the concrete. as a further precaution, circumferentially-placed rods were used on the landward side of the river lines, mainly to assist in preventing the distortion of shape which might occur here, either under present conditions, such as under the fowler warehouse at weehawken, or under any possible different future conditions, such as might be brought about by building some new structure in the vicinity of the tunnels. for purposes of classification of the circumferential reinforcement, the tunnel was divided into two types, "_b_" and "_c_"; (type "_a_" covering the portion which, being wholly in solid rock, was not reinforced at all). type "_b_" covers the part of the tunnels on both sides of the river lying between the point where the top of the tunnel passes out of rock and the point where the invert passes out of rock on the manhattan side, or out of gravel on the weehawken side. the reinforcement consists of twenty -in. square longitudinal rods in the crown of the tunnel, as described for the general longitudinal reinforcement, together with -in. square circumferential rods at -in. centers, and extending over the arch to ft. in. below the horizontal axis. type "_c_" extends from the latter limit of type "_b_" to the river line on each side, and consists of longitudinal reinforcement in both top and bottom, as described before, together with circumferential reinforcement entirely around the tunnel, and formed of -in. square twisted rods at -in. centers. type "_d_" consists of longitudinal reinforcement only, and extends from river line to river line, thus occupying . % of the length in which concrete is used. the reinforcement consists of twenty -in. twisted rods at -in. centers in the crown, and twenty -in. rods at -in. centers in the invert. in addition to the three standard types, "_b_," "_c_," and "_d_," there were two sub-types which were used in type "_d_," and in conjunction with it wherever the thickness of the center of the concrete arch became less than ft. in., measuring to the outside of the metal lining. this thickness was one of the limits used in laying out the lines and grades, and in general the arch was not less than this. there were one or two short lengths, however, where it was less, for, if the arch thickness requirement had been adhered to, it would have resulted in a break of line or grade for the sake of perhaps only a few feet of thin arch, and it was here that the sub-types came into play. sub-type was used where the arch was less than ft. in. thick at the top. the extra reinforcement here consisted of -in. square twisted rods, ft. long, laid circumferentially in the crown at -in. centers. sub-type was used where the arch was less than ft. in. thick at the side. the extra reinforcement here consisted of -in. square twisted rods, ft. long, laid circumferentially, at the side on which the concrete was thin, at -in. centers. very little of either of these two sub-types was used. the entire scheme is shown graphically and clearly on plate xxxvii. _cross-passage lining._--there are two main types of cross-passages: lined with steel plates, and unlined. there is only one example of lining with steel plates, namely, the most western one at weehawken. this is built in rock which carried so much water that, in order to keep the tunnels and the passage dry, it was decided to build a concrete-lined passage, without attempting to stop the flow of water, and within this to place a riveted steel lining, not in contact with the concrete, but with a space between the two. this space was drained and the water led back to the shield chamber and thence to the weehawken shaft sump. the interior of the steel lining is covered with concrete. in the passages not lined with steel plates the square concrete lining is rendered on the inside with a water-proof plaster. each of the passages is provided with a steel door. _provisions in concrete lining for surveys and observations._--the long protracted discussion as to the provision for foundations in these tunnels led to many surveys, tests, and observations, which were carried out during the constructive period, and, as it was desired to continue as many of these observations as possible up to and after the time when traffic started, certain provisions were made in the concrete lining whereby these requirements might be fulfilled. the chief points on which information was desired were as follows: the change in elevation of the tunnel, the change in lateral position of the tunnel, the change in shape of the tunnel, the tidal oscillation of the tunnel. a detailed account of these observations will be found in another paper on this work, but it may be said now that it was very desirable to be able to get this information independently of the traffic as far as possible, and therefore provision was made for carrying on the observations from the side benches. for studying the changes in level of the tunnel, a permanent bench-mark is established in each tunnel where it is in the solid rock and therefore not subject to changes of elevation; throughout the tunnel, brass studs are set in the bench at intervals of about ft. a series of levels is run every month from the stable bench-mark on each of these brass plugs, thus obtaining an indication of the change of elevation that the tunnels have undergone during the month. these results are checked on permanent bench-marks in the subaqueous portion of the tunnels. these consist of rods, encased in pipes of larger diameter, which extend down through the tunnel invert into the bed-rock below the tunnel. leakage is kept out by a stuffing-box in the invert. by measuring between a point on these rods where they pass through the invert and the tunnel itself a direct reading of the change of elevation of the tunnel is obtained. these measurements are taken at weekly intervals, and, as the tunnels are subject to tidal influences, being lower at high tide than at low tide, are always taken under the same conditions as to height of water in the river. these permanent bench-marks are at stations + and + (about ft. on the shoreward side of the river line in each case) in the south tunnel, at stations + and + , also in the south tunnel, and at station + in the north tunnel. in order to study the lateral change of position, a base line was established on the side bench at each end of each tunnel in the portion built through the solid rock. at intervals of about ft. throughout each tunnel, alignment pockets are formed in the concrete arch, also above the bench, on the south bench of the north tunnel and the north bench of the south tunnel. in each pocket is placed a graduated and verniered brass bar, so that, when the base line is projected on these bars, the lateral movement of the tunnel can be read directly. as it was desirable to have as much cross-connection as possible between the tunnels at the points where the instruments were to be set up, five of the main survey stations were set opposite each of the five cross-passages. then, for the purpose of increasing the cross-connection still further, pipes in. in diameter were put through from one tunnel to the other at axis level at stations + , + , + , + , and + , and a survey station was put in opposite each one. points were established at station + , which is the point of intersection for the curve on the original center line of the tunnel, and also at station + , where the intersection of the track center line comes in the north tunnel. as it was desirable to have the survey stations not much more than ft. apart, so as to obtain clear sights, other stations were established so that the distances between survey stations were at about that interval. for studying changes of shape in the tunnel, brass "diameter markers" were inserted at each survey station in the concrete lining at the extremities of the vertical and horizontal axes. these were pieces of brass bar, / in. in diameter and in. long, set in the concrete and projecting / in. into the tunnel, so that a tape could be easily held against the marker and read. for obtaining the tidal oscillation of elevation of the tunnel, recording gauges are attached to the invert of the tunnel at each of the five permanent bench-marks referred to above in such a way that the recording pencil of the gauge is actuated by the rod of the permanent bench-mark. a roll of graduated paper is driven by clock-work below the recording pencil which thus marks automatically the relative movement between the moving tunnel and the stable rods. these have shown that in the subaqueous part of the tunnel there is a regular tidal fluctuation of elevation, the tunnel moving down as the tide rises, and rising again when the tide falls. for an average tide of about ft. the tunnel oscillation would be about / in. before the concrete lining was placed, there was a tidal change in the shape of the tunnel, which flattened about / in. at high tide. after the concrete lining was placed, this distortion seemed to cease. the general design and plan of the work have been described, and before giving any account of the contractor's methods in carrying it out, table , showing the chief quantities of work in the river tunnels, is presented. methods of construction. the following is an account of the methods used by the contractor in carrying out the plans which have already been described. first, it may be well to point out the sequence of events as they developed in this work. these events may be divided into six periods. _ ._--excavation and iron lining: june, , to november, ; _ ._--caulking and grummeting the iron lining: november, , to june, ; _ ._--surveys, tests and observations: april, , to april, ; _ ._--building cross-passages and capping pile bores: april, , to november, ; _ ._--placing the concrete lining: november, , to june, ; _ ._--cleaning up and various small works: june, , to november, . the tunnels were under an average air pressure of lb. per sq. in. above normal for all except periods and , during which times there was no air pressure in the tunnels. all the work will be described in this paper except that under period which will be found in another paper. _period .--excavation and iron lining, june, , to november, ._--table gives the chief dates in connection with this period. _manhattan shield chambers._--the manhattan shield chamber construction will be first described. the weehawken shield chambers have been described under the land tunnel section, as they are of the regular masonry-lined land tunnels type, whereas the manhattan chambers are of segmental iron lining with a concrete inner lining. during the progress of excavation, the location of the new york shield chambers was moved back ft., as previously described in the "land tunnel" section, and when the location had been finally decided, there was a middle top heading driven all through the length now occupied by the shield chamber. narrow cross-drifts were taken out at right angles to the top heading, and from the ends of these the wall-plate headings were taken out. heavy timbering was used, as the rock cover was only about ft., and the whole span to be covered was ft. the process adopted was to excavate and timber the north side first, place the iron lining, and then excavate the south side, using the iron of the north side as the supports for the north ends of the segmental timbering of the south. the only incident of note was that at : a.m., on october th, , the rock at the west end of the south wall-plate heading was pierced. water soon flooded the workings, and considerable disturbance was caused in the new york central railroad yard above. the cavity on the surface was soon filled in, but to stop the flow of mud and water was quite a troublesome job. table .--quantities of work in subaqueous tunnels. ============================+========================================= | type. |----------+--------------+--------------+ description, quantity, |manhattan | cast iron, | cast iron, | length, etc. |shield | ordinary | ordinary | |chambers. | pocketless. | pocket. | ----------------------------+----------+--------------+--------------+ length, in feet. | . | , . | , . | ----------------------------+----------+--------------+--------------+ excavation, in cubic yards. | | | | total. | , | , | , | per linear foot. | . | . | . | cast-iron tunnel lining, | | | | in pounds. | | | | total. | , | , , | , , | per linear foot. | , | , | , | cast-steel tunnel lining, | | | | in pounds. | | | | total. | | , , | , | per linear foot. | | . | . | steel bolts and washers, | | | | in pounds. | | | | total. | , | , , | , | per linear foot. | . | . | . | rust joints, in linear feet.| | | | total. | , | , | , | per linear foot. | . | . | . | concrete, in cubic yards. | | | | total. | | , | , | per linear foot. | . | . | . | steel beams, plates, etc., | | | | in pounds. | | | | total. | , | , | , | per linear foot. | , . | . | . | steel bolts, hooks, etc., | | | | in pounds. | | | | total. | , | , | , | per linear foot. | . | . | . | expanded metal, in pounds. | | | | total. | | , | , | per linear foot. | . | . | . | vitrified conduits, in | | | | duct feet. | | | | total. | , | , | , | per linear foot. | . | . | . | ============================+==========+==============+==============+ ============================+========================================== | |--------------+-------------+------------- description, quantity, | cast iron, | cast steel, | length, etc. | heavy | ordinary | total. | pocketless. | pocketless. | ----------------------------+--------------+-------------+------------- length, in feet. | , . | . | , . ft. ----------------------------+--------------+-------------+------------- excavation, in cubic yards. | | | total. | , | , | , per linear foot. | . | . | cu. yd. cast-iron tunnel lining, | | | in pounds. | | | total. | , , | | , , per linear foot. | , | | lb. cast-steel tunnel lining, | | | in pounds. | | | total. | , , | , , | , , per linear foot. | . | , . | lb. steel bolts and washers, | | | in pounds. | | | total. | , , | , | , , per linear foot. | . | . | lb. rust joints, in linear feet.| | | total. | , | , | , per linear foot. | . | . | ft. concrete, in cubic yards. | | | total. | , | | , per linear foot. | . | . | cu. yd. steel beams, plates, etc., | | | in pounds. | | | total. | , | , | , per linear foot. | . | . | lb. steel bolts, hooks, etc., | | | in pounds. | | | total. | , | , | , per linear foot. | . | . | lb. expanded metal, in pounds. | | | total. | , | | , per linear foot. | . | . | lb. vitrified conduits, in | | | duct feet. | | | total. | , | , | , per linear foot. | . | . | duct ft. ============================+==============+=============+============ table .--excavation and iron lining. ====================================+================+================| | north | north | | manhattan. | weehawken. | ------------------------------------+----------------+----------------| shaft and preliminary headings. | june , ' . | june , ' . | begun. | | | shaft and preliminary headings. |december , ' |september , ' | finished. | | | excavation of shield chamber. begun.| may , ' . |january , ' .| excavation of shield chamber. |january , ' .| march , ' . | finished. | | | cast-iron lining of shield chambers.|february , ' .| none. | begun. | | | cast-iron lining of shield chambers.| march , ' . | none. | finished. | | | excavation of tunnels begun before |october , ' .|january , ' .| installation of shield. | | | commenced building falsework for | march , ' . | march , ' . | shield. | | | shield parts received at shaft. | march , ' . | march , ' . | erection of shield begun. | march , ' . | march , ' . | erection of shield (structural | march , ' . | april , ' . | steel). finished. | | | erection of shield (hydraulic | may , ' . | may , ' . | fittings). finished. | | | first ring of permanent cast-iron | may , ' . | may , ' . | lining put in. | | | first air lock bulkhead wall. begun.| may , ' . | june , ' . | first air lock bulkhead wall. | june , ' . | june , ' . | finished. | | | air pressure first put in tunnel. | june , ' . | june , ' . | rock disappeared from invert of |december , ' .|october , ' .| tunnel. | | | first pair of bore segments built in|december , ' .|january , ' .| tunnel. | | | rip-rap of river bulkhead wall met. |february , ' .| none. | first pile met (in river bulkhead |february , ' |january , ' . | wall at manhattan, and fowler | | | warehouse foundation at weehawken). | | | last pile met. | march , ' . |february , ' .| first ring erected on river side of | march , ' . |february , ' .| shore line. | | | removing hood of shield. begun. | march , ' . |february , ' .| removing hood of shield. finished. | april , ' . |february , ' .| second air-lock bulkhead wall. | may , ' . | march , ' . | begun. | | | second air-lock bulkhead wall. | may , ' . | march , ' . | finished. | | | ------------------------------------+----------------+----------------| tunnel holed through with meeting | september , . | tunnel. | | last ring of permanent cast-iron | october , . | lining built in. | | ====================================+================+================| ====================================+================+================| | south | south | | manhattan. | weehawken. | ------------------------------------+----------------+----------------| shaft and preliminary headings. |june , ' . |june , ' . | begun. | | | shaft and preliminary headings. |december , |september , | finished. |' . | | excavation of shield chamber. begun.|may , ' . |january , ' .| excavation of shield chamber. |may , ' . |april , ' . | finished. | | | cast-iron lining of shield chambers.|may , ' . |none. | begun. | | | cast-iron lining of shield chambers.|june , ' . |none. | finished. | | | excavation of tunnels begun before |january , ' . |january , ' .| installation of shield. | | | commenced building falsework for |june , ' . |april , ' . | shield. | | | shield parts received at shaft. |june , ' . |april , ' . | erection of shield begun. |june , ' . |april , ' . | erection of shield (structural |june , ' . |may , ' . | steel). finished. | | | erection of shield (hydraulic |august , ' . |june , ' . | fittings). finished. | | | first ring of permanent cast-iron |august , ' . |june , ' . | lining put in. | | | first air lock bulkhead wall. begun.|september , |june , ' . | |' | | first air lock bulkhead wall. |september , |july , ' . | finished. |' | | air pressure first put in tunnel. |october , ' . |july , ' . | rock disappeared from invert of |february , ' .|september , | tunnel. | | | first pair of bore segments built in|february , |december , ' | tunnel. |' . | | rip-rap of river bulkhead wall met. |april , ' . |none. | first pile met (in river bulkhead |april , ' . |december , ' .| wall at manhattan, and fowler | | | warehouse foundation at weehawken). | | | last pile met. |may , ' . |january ' . | first ring erected on river side of |may , ' . |january , ' .| shore line. | | | removing hood of shield. begun. |may , ' . |january , ' .| removing hood of shield. finished. |may , ' . |january , ' .| second air-lock bulkhead wall. |july , ' . |march , ' . | begun. | | | second air-lock bulkhead wall. |july , ' . |march , ' . | finished. | | | ------------------------------------+----------------+----------------| tunnel holed through with meeting | october , . | tunnel. | | last ring of permanent cast-iron | november , . | lining built in. | | ====================================+================+================+ the excavation was begun on may th, , and finished on may th, . the segments were placed by an erector consisting of a timber boom supported by cross-timbers running on car wheels on longitudinal timbers at each side of the tunnel. motion was transmitted to the boom by two sets of tackle, and the heavy ( , -lb.) segments were easily handled. the erection of the lining was started on february th, , and finished on june th, . while the shield chambers were being excavated, bottom headings were run along the lines of the river tunnels and continued until the lack of rock cover prevented their being driven further. these were afterward enlarged to the full section as far as possible. the typical working force in the shield chambers was as follows: _ten-hour shifts._ _drilling and blasting._ foreman @ $ . drillers " . drillers' helpers " . blacksmith " . blacksmith's helper " . powderman " . waterboy " . nipper " . machinist " . machinist's helper " . _mucking._ or foremen @ $ . muckers " . [illustration: plate xxxviii. trans. am. soc. civ. engrs. vol. lxvii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. . fig. .] _erection of shields._--the tunneling shields have been described in some detail in the section of this paper dealing with the contractor's plant. they consist essentially of two parts, the structural steelwork and the hydraulic fittings. the former was made by the riter conley manufacturing company, of pittsburg, pa., and put up by the terry and tench company, of new york city; the hydraulic fittings were made and put in by the watson-stillman company, of new york city. on the new york side, the shields were built inside the iron lining of the shield chambers, hence no falsework was needed, as the necessary hoisting tackle could be slung from the iron lining; at weehawken, however, the erection was done in the bare rock excavation, so that timber falsework had to be used. the assembly and riveting took about weeks for each shield; the riveting was done with pneumatic riveters, using compressed air direct from the tunnel supply. after the structural steel had been finished, the shields, which had hitherto been set on the floor of the chambers in order to give room for working over the top, were jacked up to grade; this involved lifting a weight of tons. while the hydraulic fittings were being put in, the shields were moved forward on a cradle, built of concrete with steel rails embedded, on which the shield was driven for the length in which the tunnel was in solid rock. the installation of the hydraulic fittings took from to weeks per shield. the total weight of each finished shield was about tons. the completed shield, as it appeared in the tunnel, is shown by fig. , plate xxxviii. the typical force working on shield erection was as follows: _ten-hour shifts._ _shield erection._ (_terry and tench._) superintendent @ $ . per day foremen " . " " timekeeper " . " " engineers " . " " iron workers " . " " laborers " . " " _hydraulic work._ (_watson-stillman company._) mechanics @ $ . per day _general labor._ (_o'rourke engineering construction company._) inspector @ $ . per day foreman " . " " laborers " . " " engineer " . " " after the shield was finished and in position, the first two rings of the lining were erected in the tail of the shield. these first rings were then firmly braced to the rock and the chamber lining; then the shield was shoved ahead by its own jacks, another ring was built, and so on. the description of the actual methods of work in the shield-driven tunnels can now be given; this will be divided generally into the different kinds of conditions met at the working face, for example, full face of rock, mixed face, full face of sand and gravel, under river bulkhead, and full face of silt. the last heading is the one under which by far the longest length of tunnel was driven, and, as not much has hitherto appeared descriptive of the handling of a shield, through this material, considerable space will be devoted to it. _full face of rock._--as was described when dealing with the shield chambers, as much as possible of the rock excavation was done before the shields were installed. on the new york side, about ft. of tunnel was completely excavated, with ft. of bottom headings beyond that, and at weehawken, and ft. of tunnel and heading beyond, respectively. this was chiefly done to avoid handling the rock through the narrow shield doors. test holes were driven ahead at short intervals to make sure that the rock cover was not being lost, but, nevertheless, at weehawken, on february th, , a blast broke through the rock and let the mud flow in, filling the tunnel for half its height for a distance of ft. from its face. throughout the rock section the shield traveled on a cradle of concrete in which were embedded either two or three steel rails. in the portion in which the whole of the excavation had been taken out, it was only necessary to trim off projecting corners of rock. in the portion in which only a bottom heading had been driven, the excavation was completed just in front of the shield, the drilling below axis level being done from the heading itself, and above that from the front sliding platforms of the shield. the holes were placed near together and drilled short, and very light charges of powder were used, so as to lessen the chance of knocking the shield about too much. in this work the small shield doors hampered the work greatly, and it might have been well to have provided a larger bottom opening which could have been subdivided or partly closed when soft ground was met; on the other hand, the quantity thus handled was small, owing to the fact that the greater part of the rock was excavated before the shields were installed. the space outside the lining was grouted with a : mixture of portland cement and sand. large voids were hand-packed with stone before grouting. the details of grouting will be described later. a typical working gang is given herewith. two such gangs were worked per shield per hours, hours per shift. all this work was done under normal air pressure. _general:_ ½ tunnel superintendent @ $ . per month assistant tunnel superintendent " . per day general foreman " . " " ½ electrician " . " " ½ electrician's helper " . " " ½ pipefitter " . " " ½ pipefitter's helper " . " " _drilling:_ foreman " . " " drillers " . " " drillers' helpers " . " " nipper " . " " ½ waterboy " . " " ½ powderboy " . " " _mucking:_ foreman " . " " muckers " . " " _erecting iron and driving shield:_ erector runner " . " " iron workers " . " " the duties of such a gang were as follows: the tunnel superintendent looked after both shifts of one shield. the assistant or "walking boss" had charge of all work in the tunnel on one shift. the general foreman had charge of the labor at the face. the electricians looked after repairs, extensions of the cables, and lamp renewals. the pipefitters worked in both tunnels repairing leaks in pipes between the power-house and the working faces, extending the pipe lines, and attending to shield repairs, and in the latter work the erector runner helped. the drillers stuck to their own jobs, which were not subject to interruption as long as the bottom headings lasted. one waterboy and one powderboy served two tunnels. the muckers helped the iron men put up the rings of lining, as well as doing their own work. the iron men tightened bolts, whenever not actually building up iron. the list does not include the transportation gang, which will be described under its own heading. the rate of progress attained was . ft. per day per shield where most of the excavation had been done before, and . ft. where none had been done before. when the shields had got far enough away from the shield chamber, and before rock cover was lost, the first air-lock bulkhead walls were put in. _air-lock bulkhead walls._--the specifications required these walls and all their fittings to be strong enough to stand a pressure of lb. per sq. in. accordingly, all the walls were of concrete, ft. in thickness, except the first two, which were ft. in thickness, and grouted up tight. there were three locks in each bulkhead wall capable of holding men, namely, the top or emergency lock which is set high in order to afford a safe means of getting away in case of a flood; this lock was used continuously for producing the lines and levels into the tunnels. it was very small and cramped for this purpose, and a larger one would have been better, both for lines and emergencies. this lock was directly connected with the overhead platform (also called for in the specifications) which ran the whole length of the tunnels. side by side, on the level of the lower or working platform of the tunnel, were the man lock and the muck lock. in addition a number of pipes were built in to give access to the cables and for passing pipes, rails, etc., in and out. after each tunnel was about , ft. ahead of the first walls, a second wall was built just like the first, and no others were put in, so that altogether there were eight walls. this second wall not only gave an added safeguard to the tunnel but enabled the air pressure at the working face to be divided between the two walls, and this compression or decompression in stages, separated by a spell of walking exercise, was found to be very good for the health of those working in the air. _mixed face._--when the rock cover became so thin that it was risky to go on without the air pressure, the air pressure was turned on, starting with from to lb., which was enough to stop the water from the gravel on top of the rock. at first, when the surface of the rock was penetrated, the soft face was held up by horizontal boards braced from the shield until the shield was shoved. the braces were then taken out and, as soon as the shield had been shoved, were replaced by others. as the amount of soft ground in the face increased, the system of timbering was gradually changed to one of -in. poling boards resting on top of the shield and supported at the face by vertical breast boards, in turn held by by -in. walings braced both through the upper doors to the iron lining and from the sliding platforms of the shield. the latter were in their forward position before the shield was shoved, the pressure being turned off and the exhaust valves opened just before the shove began. as the shield went ahead, the platform jacks gradually exhausted and thus held enough pressure on the face to keep it up. fig. is a sketch of this method. in driving through mixed ground a typical working gang was about as follows: _general:_ / tunnel superintendent @ $ . per month assistant tunnel superintendent " . per day general foreman " . " " ½ electrician " . " " ½ electrician's helper " . " " ½ pipefitter " . " " ½ pipefitter's helper " . " " _drilling:_ foreman " . " " drillers " . " " drillers' helpers " . " " _timbering:_ timbermen @ $ . per day timbermen's helpers " . " " _mucking:_ foreman " . " " muckers " . " " _erecting iron and driving shield:_ erector runner " . " " iron workers " . " " the average rate of progress was . ft. per day. in this case there were three such gangs, each on an -hour shift. _full face of sand and gravel._--this condition of affairs was only met at weehawken. two systems of timbering were used. in the first system, fig. , the ground was excavated ft. in. ahead of the cutting edge, the roof being held by longitudinal poling boards, resting on the outside of the skin at their back end and on vertical breast boards at the forward end. when the upper part of the face was dry, it was held by vertical breast boards braced from the sliding platform and through the shield doors to cross-timbers in the tunnel; the lower part, which was always wet, was held by horizontal breast boards braced through the lower shield pockets to cross-timbers in the tunnel. this system worked all right as long as the ground in the top was sandy enough and had sufficient cohesion to allow the polings to be put in, but, when the upper part was in gravel, thus making it impossible to put in the longitudinal polings or the vertical breasting, the second system came in. here the excavation was only carried ft. in. (half a shove) ahead of the cutting edge, and the longitudinal polings were replaced by transverse boards supported by pipes which were placed in the holes provided in the shield to accommodate some telescopic poling struts which had been designed but not made. these pipes acted as cantilevers, and were in two parts, a ½-in. pipe wedged tight into the holes and smaller pipes sliding inside them. after a small section of the ground had been excavated, a board was placed against it, one of the pipes was drawn out under it, and wedges were driven between it and the board. these polings were kept below the level of the hood, so that when the shield was shoved they would come inside of it; in addition, they were braced with vertical posts from the sliding platforms. the upper part of the face was held by longitudinal breast boards braced from the sliding platform by vertical "soldier" pieces. the lower part of the face was supported by vertical sheet-piling braced to the tunnel through the lower doors. sometimes two rows of piling were used, but generally one, as shown in fig. . notwithstanding the fact that the breasting was only ft. in. ahead of the hood, the shield was moved its full stroke of ft. in., the ground around the cutting edge of the hood being scraped away by men working bars in the place from which the temporary breast boards at the circumference had been removed. the back pressure on the sliding platform jacks, when the exhaust valves were only partly open, offered a good deal of resistance, and held the face as long as the movement of the shield was continuous. [illustration: method of timbering face in mixed ground method of timbering face in sand method of timbering face in sand and gravel fig. .] on one occasion, when for some reason the shield was stopped with the shove only partly done, and the exhaust valves had not been shut off, the platforms continued to slide and allowed the face to collapse; the shield platforms and doorways, however, caught the falling sand and gravel and the flow choked itself. as soon as the rock surface was penetrated and the sand and gravel were met, which happened almost at the same time in the two weehawken tunnels, the escape of air increased enormously, and it at once became clear that it was impossible to keep enough air in the two tunnels by the methods then in use, even when working the three compressors, each capable of compressing , cu. ft. of free air per min. at top speed. when the shields just entered the sand and gravel, the face had been held by light breasting, without any special effort to prevent the escape of air, but when it was found impossible to supply enough air, a large amount of straw and clay was used in front of the boards. this cut down the escape, but, as much air was escaping through the joints of the iron lining, these were plastered with portland cement. even then, the loss was too great, therefore one tunnel was shut down entirely and all the air was sent to the other. this allowed a pressure of lb. to be kept up in the working tunnel, and this, though less than the head, was enough to allow progress to be made. in order to use one tunnel as a drain for the other, the two faces were always kept within ft. of each other by working them alternately. the timbered face was never grouted, though this would have reduced the loss of air, as at the same time it would have decreased the progress very much, and any one who saw the racing engines in the power-house, and realized that a breakdown of one of them would mean the loss of the faces, was ready to admit that the quicker this particular period was cut short, the better. above the sand and gravel lay the silt, and, when it showed in the roof, the escape of air was immediately reduced and the two faces could be worked simultaneously. almost at the same time the piles supporting the large warehouse, known as the fowler building, were met. although the face now took much less timber, the same system of breast boards as had been used in the gravel was kept up, but in skeleton form. they were set ft. in. ahead of the shield, however, instead of ft. in., and the transverse roof poling boards were replaced by longitudinals resting on the shield. the more piles in the face the less timbering was done. the piles were cut into handy lengths with axes and chisels. all timbering was light compared with the weight of the ground, but, as the shove took place as soon as the set was made, it served its purpose. when a face was closed down the whole system was greatly reinforced by braces from the shield, the face of which was closed by the doors. in driving through such a face the typical -hour shift gang was about as follows: _general:_ / tunnel superintendent @ $ . per month. assistant tunnel superintendent " . per day. general foreman " . " " ½ pipefitter " . " " ½ pipefitter's helper " . " " ½ electrician " . " " ½ electrician's helper " . " " _timbering:_ timbermen " . " " timbermen's helpers " . " " _mucking:_ foreman " . " " muckers " . " " _erecting iron and driving shield:_ erector runner " . " " foreman " . " " iron workers " . " " the drillers were not kept on after the rock disappeared; a foreman was added who divided his time between iron erection and mucking. the average rate of progress in sand and gravel without piles was . ft. per day per shield. when piles and silt were met in the upper part of the face, the speed increased to . ft. per day. _passing under river bulkhead._--at weehawken no trouble was found in passing under the river wall, as the bulkhead consisted of only cribwork supported on silt, and, though the piles obstructed the motion of the shield, they were easily cut out, and the cribwork itself was well above the top of the shield. on the new york side, however, conditions were not nearly as good. the heavy masonry bulkhead was supported on piles and rip-rap, as shown in fig. . the line of the top of the shield was about ft. above the bottom of the rip-rap, the spaces between the stones of which were quite open and allowed a free flow of water directly from the river. as soon, therefore, as the cutting edge of the shield entered the rip-rap there was a blow, the air escaping freely to the ground surface behind the bulkhead and to the river in front of it. clay puddle, or mud made from the excavated silt, was used in large quantities to plug up the interstices between the stone in the working face, the air pressure being slightly greater than that needed to keep out the water holding it in place. the excavation of the rip-rap was a tedious affair, for it had to be removed one stone at a time and the spaces between the newly exposed stones plugged with mud immediately. one man stood ready with the mud while another loosened the stones with a bar. when the shield had advanced its own length in the rip-rap, another point for the escape of the air was exposed at the rear end of the shield. this loss was closed at the leading end of the last ring with mud and cement sacks. [illustration: sketch showing river tunnels passing under river bulkhead wall at manhattan cross-section of river bulkhead wall on axis of north tunnel plan showing piles removed to allow passage of shield fig. .] as long as the shield was stationary it was possible, by using these methods and exercising great care and watchfulness, to prevent excessive loss of air; but, while the shield was being shoved ahead, the difficulties were much increased, for the movement of the shield displaced the bags and mud as fast as they were placed, and it was only by shoving slowly and having a large number of men looking out for leaks and stopping them up the instant they developed that excessive loss of air could be prevented. in erecting the iron lining, as each segment was brought into position, it was necessary to clean off the leading surface of the previous ring and the adjacent portion of the tail of the shield; this was always accompanied by a slight "blow," and for some time the air pressure in the tunnel dropped from to lb., that is, from greater than the balancing pressure to less, every time a segment was placed, and on two occasions the "blow" became so great that the tunnel pressure was reduced considerably further, and in consequence the water from the river rushed in and was not stopped until it had risen about ft. in the tunnel invert. on such occasions the surface of the river was greatly disturbed, rising more than ft. in the air in a sort of geyser. a large quantity of grout (about , bbl. of cement and a similar quantity of sand in the north tunnel and , bbl. in the south tunnel) was used at this point; it was forced through the tunnel lining immediately behind the shield, greatly reducing the loss of air and helping to bind the rip-rap together. when the shield had traveled ft. through the rip-rap, the piles which support the bulkhead were met. one hundred of these which were spaced at -ft. centers in each direction, were cut out of the path of each shield in a distance of ft. the presence of the piles caused considerable extra labor, as each pile had to be cut into several pieces with axes to enable it to be removed through the shield doors, otherwise they presented no difficulties. it was not necessary to timber the face, as the piles supported it most effectively. when the river line had been passed, the "blow" still continued, and as there was no heavy ground above the tunnel the light silt was carried away into the water by the escaping air. at one time the cover over the crown of the tunnel was reduced to such an extent that for a distance of ft. there was less than ft. of very soft silt, and in some places none at all. therefore, the shield was stopped and the air pressure reduced until it was less than the balancing pressure; the blow then ceased, and about , cement bags filled with mud were dumped into the hole (the location made it impossible to dump them _en masse_ from a scow). they were then weighted down with rip-rap. this sealed the blow, and the work was continued without any further disturbance from this source. just before the blow reached its maximum it was found that two of the piles which had been encountered were directly in the path of one of the proposed screw-piles. it was therefore decided to pull these, and this was done with two -ton hydraulic jacks supported by the upper sliding platforms and acting on a horizontal timber which was connected to the piles by tie-rods and chains. the working force here was similar to that employed in the sand and gravel section previously described. _in full face of silt._--a full face of silt was first met under the new york central railroad freight yard on the new york side. up to this point the ground passed through had been either solid rock or a mixed face of rock and gravel. in both of these the full excavation had to be taken out before the shield could be shoved, and the soft ground had needed timbering. when the rock, gravel, and hardpan gave place to a full face of silt, the timber was removed, all the shield doors were opened, and the shield was shoved into the ground without any excavation being done by hand ahead of the diaphragm. as the shield advanced, the silt was forced through the open doors into the tunnel. after the work had gone on in this way for some time, taking in about % of the full volume of the tunnel excavation per foot forward, the air pressure was raised from to lb. the result was that the silt in the face got harder and flowed less readily through the shield, and the amount taken in fell to about % of the full volume. this manner of shoving at once caused a disturbance on the surface and the railroad tracks above the tunnel were raised, so that the pressure was lowered to lb., then the muck got softer and the full volume of excavation was taken in; after a while the pressure was again raised to lb. the forcing of the shield through the silt resulted in a rising of the bed of the river, the amount that the bed was raised depending on the quantity of material brought into the shield. if the whole volume of excavation was being brought in, the surface of the bed was not affected; when about % was being taken in, the surface was raised about ft.; if the shield was being driven blind, the bed was raised about ft. the number of open doors was regulated so as to take in the minimum quantity of muck consistent with causing no surface disturbance. on the average, in the north manhattan tunnel, all the doors were open, but in the south tunnel there were generally only five or six out of the total nine. in front of the bulkhead wall at manhattan the tunnels were under pier no. . this structure was supported on wooden piles, some ft. or more in length, which came down below the tunnel invert. the piles which lay directly in the path of the tunnels, with a few exceptions, had been pulled. in driving the tunnels through this section, great care had to be taken not to disturb the piles on either side of the tunnels, as they supported a heavy trestle used in disposing of the excavation from the open cut in the terminal yard. to avoid such disturbance, a large portion of the total excavation had to be taken through the shields. the first shield which passed the river bulkhead was the south one at weehawken. as soon as this line was crossed the silt was found to be much softer than behind the wall, in fact it was like a fluid in many of its properties. the fluidity could be changed by varying the tunnel air pressure; for example, when the air pressure was made equal to the weight of the overlying material (water and silt), the silt was quite stiff, and resembled a rather soft clay; but when the air pressure was from to lb. per sq. in. lower, it became so liquid that it would flow through a ½-in. grout hole in the lining, in a thick stream, at the rate of from to gal. per min. as soon as the plug was taken out. this was the point to which the contractor had long looked forward, as he expected to be able to close all his shield doors and drive the rest of the way across without taking in a shovelful of muck, as had just been done under the hudson river, on the south tunnel of the hudson and manhattan railroad company's tunnels between morton street, new york city, and hoboken, n. j. the doors were shut and the shield was shoved; the tunnel at once began to rise rapidly, notwithstanding that the heaviest possible downward leads that the clearance between the iron and the shield would allow were put on. at the same time, the pressures induced in the silt by the shield shouldering the ground aside caused the iron lining to rise about in. as soon as the shield left it, and also distorted it, the horizontal diameter decreasing and the vertical diameter increasing by about as much as ¼ in. an anxious discussion followed these phenomena, as the effects had been so utterly unexpected, and a good many different theories were advanced as to the probable cause. it was thought that the hood of the shield might have something to do with the trouble. the shield was stopped, the hood removed, the doors were shut, and the driving continued. the same trouble was found, and it was impossible to keep to grade. work was stopped, and the question was thoroughly debated; finally, on january st, , the chief engineer directed that one of the shield doors be opened as an experiment and % of the excavation taken in. the effect was instantaneous, the shield began to come down to grade at once, and it soon became necessary to close the door partially and reduce the quantity of muck taken in in order to prevent the tunnel from getting below grade. the other troubles from distortion, etc., ceased at the same time. it was soon found that a powerful aid in the guidance of the shield was thus brought to hand, for, if high, the shield could be brought down by increasing the quantity of muck taken in, if low, by decreasing it. from this time forward, the quantity of muck taken in at each shove was carefully regulated according to the position of the tunnel with regard to grade and the nature of the ground. the quantity varied from nothing to the full volume displaced by the tunnel, and averaged % of the latter. to regulate the flow, the bottom middle door was fitted with two steel angles behind which were placed by -in. timbers. in this way the opening could be entirely closed or one of any size left. the muck flowed into the tunnel in a thick stream, as shown in fig. , plate xxxv, and, by regulating the rate of shove it could be made to flow just as fast as it could be loaded into cars. in driving through the silt, the typical gang per shift of hours per shield was as follows: _general:_ / tunnel superintendent @ $ per month assistant tunnel superintendent " . per day general foreman " . " " ½ electrician " . " " ½ electrician's helper " . " " foreman " . " " pipefitters " . " " pipefitters' helpers " . " " _mucking:_ foreman " . " " muckers " . " " _erecting iron and driving shield:_ foreman @ $ . per day erector runner " . " " iron workers " . " " laborers " . " " three such shifts were worked per day, and the air pressure averaged lb. per sq. in. the increase in the number of pipefitters was due to the greatly increased speed, and also the steadily increasing length of completed tunnel. the three laborers in the erection gang spent their whole time tightening bolts. the rate of progress in the silt under the river per ring of ½ ft. was hours min., exclusive of all time when work was actually suspended. for a considerable part of the time only two -hour shifts were worked, owing to a shortage of iron caused by the change in the design of the lining, whereby the original lining was changed to a heavier one, and, as the work was also stopped for experiments and observations, the average of the actual total time, including all the time during which work was suspended, was hours min. per ring, or . ft. per day. the junction of the shields under the river was made as follows: when the two shields of one tunnel, which had been driven from opposite sides of the river approached within ft. of each other, the shields were stopped, a -in. pipe was driven between them, and a final check of lines and levels was made through the pipe. incidentally, also, the first through traffic was established by passing a box of cigars through the pipe from the manhattan shield to that from weehawken. one shield was then started up with all doors closed while the doors on the stationary shield were opened so that the muck driven ahead by the moving shield was taken in through the other one's doors. this was continued until the cutting edges came together. all doors in both shields were then opened and the shield mucked out. the cutting edges were taken off, and the shields moved together again, edge of skin to edge of skin. the removal of the cutting edge necessitated the raising of the pressure to lb. as the sections of the cutting edges were taken off, the space between the skin edges was poled with -in. stuff. fig. , plate xxxix, is a view of the shields of the north tunnel after being brought together and after parts of the interior frames had been removed. when everything except the skins had been removed, iron lining was built up inside the skins, the gap at the junction was filled with concrete, and long bolts were used from ring to ring on the circumferential joint. finally, the rings inside the shield skins were grouted. [illustration: plate xxxix. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. . fig. .] in order to make clear the nature of the work done in building these shield-driven tunnels in silt, a short description will be attempted, this description falling into three main divisions, namely, shoving the shield, pushing back the jacks, and erecting the iron lining. _shoving the shield._--this part of the work is naturally very important, as the position of the shield determines within pretty narrow limits the position of the iron built within it, hence the shield during its forward movement has to be guided very carefully. on this work certain instructions were issued for the guidance of the foreman in charge of the shield. these instructions were based on results of "checks" of the shield and iron's position by the engineering corps of the company, and comprised, in the main, two requirements, namely, the leads that were to be got, and the quantity of muck to be taken in. the "lead" is the amount that the shield must be advanced further from the iron, on one side or the other, or on the top or bottom, as measured from the front face of the last ring of iron lining to the diaphragm of the shield. these leads are not necessarily true leads from a line at right angles to the center line, as the iron may have, and in fact usually does have, a lead of its own which is known and allowed for when issuing the requirements for the shove. the foreman, knowing what was wanted, arranged the combination of shield jacks which would give the required leads and the amount of opening on the shield door which would give the required amount of muck. to see how the shield was going ahead, a man was stationed at each side at axis level and another in the crown. each man had a graduated rod on which the marks were so distinct that they could be read by anyone standing on the lower platform. these rods were held against the shield diaphragm, and, as it advanced, its distance from the leading end of the last ring could be seen by the man in control of the jack valves. if he found that he was not getting the required leads, he could change the combination of jacks in action. as the time of a shove was often less than min., the man had to be very quick in reading the rods and changing the jacks. if it was found that extensive change in the jack arrangement was wanted, the shove could be stopped by a man stationed at the main hydraulic control valve; but, as any such stoppage affected the quantity of muck taken in, it was not resorted to unless absolutely necessary. if the quantity of muck coming in was not as desired, a stop had to be made to alter the size of the opening, and if, while this was being done, the exhaust valves were not closed quite tight, the silt pressure on the face of the shield would force it back against the iron. this fact was sometimes taken advantage of when a full opening did not let in the desired quantity, for the shield could be shoved, allowed to return, and shoved again. the time taken to shove in silt varied greatly with the quantity of material taken in; for shoving and mucking combined, it averaged min., with an average of cu. yd. of muck disposed of, or about min. per cu. yd. of material. _pushing back the jacks._--this was a simple matter, and merely consisted in making the loose push-back connection to each jack as it had to be sent back. some of the jacks became strained and bent, and had to be taken out and replaced. where there was silt pressure against the face of the shield, the hydraulic pressure had to be kept on until the ring was erected. in such cases, only two or three jacks could be pushed back at a time, and only after a segment had been set in position, and the pressure taken on it, could the next jack be pushed back, and so on around the ring. the time between the finish of the shove (hydraulic pressure turned off) and the placing of the first segment, was occupied in pushing back the bottom jacks and cleaning dirt off the tail of the shield, and averaged about min. _erecting the iron lining._--as soon as the shove was over, the whole force, when in silt, set to work at building up the iron and then tightening the bolts so that the shield could be shoved again. a section of the tunnel with bolting and working platform is shown on plate xl. in the early part of the work, when the ground was being excavated ahead of the shield, the whole force, with the exception of those working in front of the shield, was engaged in erecting the iron, but, as soon as this was done, most of the men returned to the mucking, and only the iron workers continued to tighten up bolts. on the other sections, where the shield was shoved into the silt without excavating ahead, as soon as the shove was completed, the whole force was engaged in the erection of the iron and the tightening of the bolts, until they were so tight that the shield could be shoved again for another ring. the iron was brought into the tunnel on flat cars, two segments to the car, and was lifted from the car and lowered into the invert of the shield by a block and fall and chain sling, as shown in fig. , plate xxxix. the bottom three or four segments were pushed around into position with the erector, the head simply bearing against the longitudinal flange without being attached to the segment; the upper segments, however, were, as shown in fig. , plate xxxviii, and fig. , plate xli, attached to the erector, by using the expanding bar and the erector head designed by mr. patrick fitzgerald, the tunnel superintendent. this was found to be a most convenient arrangement. the single erector attached to the center of the shield was able to erect the iron as fast as it could be brought into the tunnel, and even when the weight of the segments was increased % (from , to , lb.) it always proved equal to its task, although occasionally one of the chains in the mechanism broke and delayed the work for an hour or so; but the sum of all the delays from this cause and from breaks and leaks in the hydraulic line only averaged min. per ring. the operating valve which was first used was a four-spindle turning valve, but this was replaced by a sliding valve which was found to be much more satisfactory, both in ease of operation and freedom from failure. as the iron was put into place, two of the middle bolts in each longitudinal flange and two in each circumferential one were pulled as tight as possible, and the others put in loosely; then, as soon as the ring was in position, as large a force as could be conveniently worked at one time was engaged in tightening the bolts. the shape of the tunnel depended on the thoroughness of the tightening of the bolts, and the shield was never shoved until the bolts in all the longitudinal flanges had been thoroughly tightened. in addition, all the bolts in the circumferential flanges below the axis were tightened, and at least three of the six in each segment above. after the shield had been shoved ahead, the bolts were found to have slackened, and, where the daily progress was four rings, or more, it was necessary to have a small gang of men always at this work. in order to get at the bolts, special platforms were necessary, and throughout the greater part of the work, a traveling platform was used. this enabled the men to reach handily all parts of the seven leading rings. this platform was supported and moved forward on wheels fixed on brackets to the tunnel, and was pulled forward by connecting chains every time the shield was shoved. in the early part of the work it was not possible to use platforms, because, in order to maintain the correct circular shape of the iron lining, it was necessary to put in temporary horizontal turnbuckles at axis level. these, however, were very convenient for supporting the planks which were used as a temporary bolting platform for the sides of the tunnel, and a temporary platform resting on by -in. timbers across the tunnel enabled the bolts in the crown of the tunnel to be reached, while the by -in. timbers were left in to support the emergency platform previously described (plate xl), which extended the entire length of the tunnel. the time taken to erect the iron lining became shorter and shorter as the tunnel organization became more perfect and the force better trained, so that, whereas, in the early part of the work, it frequently took hours to erect a ring, in the latter part, when the work was nearing completion, it was a common occurrence to erect a ring in min. the average time in the "heavy iron" section, which included the greater part of the work under the river, was hour min. for the erection of the ring and min. for tightening the bolts after that had been completed, so that the total time spent by the whole gang on erection and bolting averaged hour min. per ring, exclusive of the time spent by the small gang which was always engaged in tightening the bolts. the average time spent in erecting and bolting, for the whole length of the tube tunnels, was hours min. per ring. _tables of progress._--tables , , , and have been prepared to show the time taken in the various operations at each working face. [illustration: plate xli. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. .] [illustration: plate xli. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. .] in tables , , , and , the following symbols are used: _a_--including assistant superintendents, foremen, and electricians, in driving the shield, erecting iron, mucking, attending to the electric lights, and repairing the pipe line. _b_--drillers, drillers' helpers, drill foremen, and nippers. _c_--all men grouting. _d_--engineers and laborers wholly employed on transport between the first lock and the face. _e_--in rock, one car = . cu. yd.; in sand or silt = . cu. yd. in place. _f_--time between completion of mucking and putting in first plate, spent in shoving the jacks back. _g_--in ordinary iron = the whole time spent on erection and bolting. in heavy iron = the time between putting in the first plate and placing the key only. _h_--time between placing the key and starting the next shove, spent by the whole gang in tightening bolts. in addition to this, there was a small gang which spent its whole time at this work. _i_--in table the first pair of bore segments is at ring - . " " " " " " " " " " " - . " " " " " " " " " " " - . " " " " " " " " " " " - . outside diameter of tunnel = ft. in. inside " " " = ft. in. length of ring = ft. in. in the "ordinary iron" section the time is divided between mucking (which included the shoving and pushing back of the jacks) and the erection time (which included the time spent by the whole gang in tightening bolts). in the "heavy iron" section these times are all separated into "mucking," "pushing back jacks," "erecting," and "bolting," and here the bolting time included only that spent on bolts by the whole gang; in addition, there was a small gang engaged solely in tightening bolts. the lost time is the average time lost due to the break-down of hydraulic pipe lines, damaged jacks, and broken erector chains. the erection time is separated for the various kinds of rings, that is, straight ordinary rings, rings containing no. bore segments, rings containing no. bore segments, and taper rings, and it will be seen that, on the average, taper rings took min. (or %) more time to erect and to bolt than ordinary ones, and that rings containing no. bore segments took min. (or %) more. table .--shield-driven tunnel work, manhattan shaft, river tunnel north. table showing the size of the gang, the amount of excavation, and the time per ring taken for the various operations involved in building tunnel through the several kinds of ground encountered; also the extent and nature of all the unavoidable delays. table part =+===========+=======+=============+===+=============+=====+===+==+==| w| | | ave. no. | e| | | of men | i| | description | in gang | g| |-------+-------------+---+-------------+--+--+---+--+--| h| | | |ave| | | | |a | | t| | | |air| | |d |g |i | | | | | | | | |r |r |r | | o| | | |p | |s |i |o | | | f| | | |r | |h |l |u |t |t | | | | |e | |i |l |t |r |o | | | | |s | |e |i |i |a |t | i| | | |s | |l |n |n |n |a | r| section | | |u | |d |g |g |s |l | o| between | length| |r |method of |--+--+---+--| | n| rings |in feet|material |e |excavation |a |b |c |d | | -+-----------+-------+-------------+---|-------------+--+--+---+--+--| | - | . |rock | |[p] | | | | | | | - | . | " | |[p] | | | / | | | | - | . |soft rock | |[p] | | | | | | o| - | . |rock | |[p] | | | | | | r| - | . |rock and | |[p] | | | | | | d| | |earth | | | | | | | i| - | . |silt | |[p]breasting | | | | | | n| - | . | " | |[q] doors | | | | | | a| - | . |silt, piles, | |[c]breasting | | | | | | r| | |rip-rap | | | | | | | y| - | . |silt | |[q] door | | | | | | | - | . | " | |[q] doors | | | | | | | - | , . | | | | | | | | | | - | , . | | | | | | | | | -+-----------+-------+-------------+---+-------------+--+--+---+--+--| | - | . |silt | |[q] door | | | | | | | - , | . | " | |[q] " | | | | | | | , - , | . | " | |[q] " | | | | | | h| , - , | . | " | |[q] " | | | | | | e| , - , | . | " | |[q] " | | | | | | a| , - , | . | " | |[q] " | | | | | | v| , - , | . | " | |[q] " | | | | | | y| , - , | . | " | |[q] " | | | | | | | , - , | . | " | |[q] " | | | | | | | , - , | . | " | |[q] " | | | | | | | - , | . | | | | | | | | | | - , | , . | | | | | | | | | -+-----------+-------+-------------+---+-------------+--+--+---+--+--| a| - , | , . | | | | | | | | | l| - , | , . | | | | | | | | | l| | | | | | | | | | | =+===========+=======+=============+===+=============+==+==+===+==+==| table part =+===========+====+=====+=====+========+====+====+====+====+====| w| | | |av. | | time for ring | e| | | | | | erection, | i| | | |time | | hrs. and min. | g| |----+-----| | |----+----+----+----+----| h| |av. |time |per | | | | | | | t| |no. |muck-| |t | o | | | | | | |of |ing, |ring,|i | r | | | | | o| |cu. |per | |m | d | b | b | | | f| |yd. |cu. |shov-|e j | i | o | o | t | | | |per |yd. |ing |a | n | r | r | a | m | | |ring| | |f c | a | e | e | p | e | i| | | |and |o k | r | | | e | a | r| section | | | |r s | y | | | r | n | o| between | | |muck-+--------+----+----+----+----+----| n| rings |e | |ing | f | g | g | g | g | g | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | | | |time for| - | | | - | - | | - | | - | - |jacks | - | | | - | - | | - | | - | - |for | - | | | | - | o| - | | - | - |light | - | | | - | - | r| - | | - | - |iron is | - | j. | j. | - | - | d| | | | |included| | | | | | i| - | | - | - |in | - | - | - | | - | n| - | | - | - |shoving | - | - | - | - | - | a| - | | - | - |and | - | - | - | - | - | r| | | | |mucking | | | | | | y| - | | - | - | | - | - | - | - | - | | - | | - | - | | - | - | - | - | - | | - | | - | - |[n] | - | | | - | - | | - | | - | - |[n] | - | - | - | - | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | | - | - |[n] | - | - | - | - | - | | - , | | - | - | - | - | - | - | - | - | | , - , | | - | - | - | - | - | - | - | - | h| , - , | | - | - | - | - | - | - | - | - | e| , - , | | - | - | - | - | - | - | - | - | a| , - , | | - | - | - | - | - | - | - | - | v| , - , | | - | - | - | - | - | - | - | - | y| , - , | | - | - | - | - | - | - | - | - | | , - , | | - | - | - | - | - | - | - | - | | , - , | | - | - | - | - | - | - | - | - | | - , | | - | - | - | - | - | - | - | - | | - , | | - | - |[n] | - | - | - | - | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| a| - , | | - | - |[n] | - | - | - | - | - | l| - , | | - | - |[n] | | | | | - | l| | | | | | | | | | | =+===========+====+=====+=====+========+====+====+====+====+====| table part =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| w| | bolting time, whole |time| | e| | time on bolts after | | | i| | ring is complete. |lost| total time. | g| |----+----+----+----+----| |-----+-----+-----+-----+-----| h| | | | | | |re- | | | | | | t| | o | | | | |pair- | | | | | | | r | | | | |ing | | | | | | o| | d | b | b | | | | o | | | | | f| | i | o | o | t | |hy- | r | | | | | | | n | r | r | a | m |drau- d | b | b | | | | | a | e | e | p | e |lic | i | o | o | t | | i| | r | | | e | a | | n | r | r | a | m | r| section | y | | | r | n |pip-| a | e | e | p | e | o| between |----+----+----+----+----|ing | r | | | e | a | n| rings | h | h | h | h | h | | y | | | r | n | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| | - | excavation partially completed previously. | | - |} {| | - | | | - | - | o| - |} {| | - | | | | - | r| - |} {| | - | | | - | - | d| - |} {| | - | | | - | - | i| |} {| | | | | | | n| - |} {| | - | - | - | | - | a| - |} bolting time for {| - | - | - | - | - | - | r| - |} light iron is {| | - | - | - | - | - | y| |} included in {| | | | | | | | - |} erection. {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | | | - | - | | - |} {| - | - | - | - | - | - | -+-----------|} {|----+-----+-----+-----+-----+-----| | - |} {| - | - | - | - | - | - | | - , | - | - | - | - | - | | - | - | - | - | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | h| , - , | - | - | - | - | - | - | - | - | - | - | - | e| , - , | - | - | - | - | - | | - | - | - | - | - | a| , - , | - | - | - | - | - | | - | - | - | - | - | v| , - , | - | - | - | - | - | | - | - | - | - | - | y| , - , | - | - | - | - | - | | - | - | - | - | - | | , - , | - | - | - | - | - | | - | - | - | - | - | | , - , | - | - | - | - | - | | - | - | - | - | - | | - , | - | - | - | - | - | | - | - | - | - | - | | - , |[o] | | | | | - | - | - | - | - | - | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| a| - , |[o] | | | | | - | | | | | - | l| - , |[o] | | | | | - | | | | | - | l| | | | | | | | | | | | | =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| table summary part ===+===========+=======+==============+====+============+==+==+===+==+==| | | | ave. no. | w| | | of men | e| | description | in gang | i| |-------+--------------+----+------------+--+--+---+--+--| g| | | |ave.| | | | | | | h| | | |air | | | | | | | t| | | | | | | | | a| | | | | |p | | | d| g | i| | o| | | |r | | | r| r | r| | f| | | |e | | s| i| o | | | | | | |s | | h| l| u | t|t | i| | | |s | | i| l| t | r|o | r| section | | |u | | e| i| i | a|t | o| between |length | |r |method of | l| n| n | n|a | n| rings |in feet| material |e |excavation | d| g| g | s|l | ---+-----------+-------+--------------+----+------------+--+--+---+--+--| o {| - | . |rock | | [p] | | | | | | r {| - | . |earth and rock| | [p] | | | / | | | d {| - | . |silt | |[p]breasting| | | | | | i {| - | . | " | |[p]breasting| | | | | | n {| - | . | " | |[q] doors | | | | | | a {|-----------+-------+--------------+----+------------+--+--+---+--+--| r {| - | , . | | | | | | | | | y {|-----------+-------+--------------+----+------------+--+--+---+--+--| {| - | , . | | | | | | | | | ---+-----------+-------+--------------+----+------------+--+--+---+--+--| hvy| - , | , . |silt | |[q] door | | | | | | ---+-----------+-------+--------------+----+------------+--+--+---+--+--| all| - , | , . | | | | | | | | | ===+===========+=======+==============+====+============+==+==+===+==+==| table summary part ===+========+========+=======+=======+====+=====+===============+========| w | | | | unavoidable delays | e | | | average time |(not included in average| i o| | | per ring. | time per ring). | g f| | |-------+-------+----+-----+---------------+--------| h |average | time | | | | | | | t i| no. of |mucking,|shoving| | | | | | r| cubic | per | and | erec- | | | | | o| yards | cubic |mucking| tion |lost| | | time | n|per ring| yard | [n] | [o] |time|total| items |hrs min| ---+--------+--------+-------+-------+----+-----+---------------+--------| o {| | | | - | | |first bulkhead | | r {| | - | - | - | | - |second bulkhead| | d {| | - | - | - | - | - |grouting | | i {| | - | - | - | - | - |blowout | | n {| | - | - | - | - | - |cradle | | a {|--------+--------+-------+-------+----+-----+---------------+--------| r {| | - | - | - | - | - |total | | y {|--------+--------+-------+-------+----+-----+---------------+--------| {| | - | - | - | - | - |per ring | | ---+--------+--------+-------+-------+----+-----+---------------+--------| hvy| | - | - | - | - | - | | | ---+--------+--------+-------+-------+----+-----+---------------+--------| all| | - | - | - | - | - | | | ===+========+========+=======+=======+====+=====+===============+========| [n] including time for jacks. [o] including bolting time. [p] excavating ahead of shield. [q] shoving shield into silt with ... doors open. table .--shield-driven tunnel work, manhattan shaft, river tunnel south. table showing the size of the gang, the amount of excavation, and the time per ring taken for the various operations involved in building tunnel through the several kinds of ground encountered; also the extent and nature of all the unavoidable delays. table part =+===========+=======+==================+===+============+==+==+==+==+==| w| | | ave. no. | e| | | of men | i| | description | in gang | g| |-------+------------------+---+------------+--+--+--+--+--| h| | | |ave| | | | |a | | t| | | |air| | |d |g |i | | | | | | | | |r |r |r | | o| | | |p | |s |i |o | | | f| | | |r | |h |l |u |t |t | | | | |e | |i |l |t |r |o | | | | |s | |e |i |i |a |t | i| | | |s | |l |n |n |n |a | r| section | | |u | |d |g |g |s |l | o| between | length| |r |method of |--+--+--+--| | n| rings |in feet|material |e |excavation |a |b |c |d | | -+-----------+-------+------------------+---+------------+--+--+--+--+--| | - | . |rock | |[r] | | | | | | | - | . |rock and earth | |[r] | | | | | | o| - | . |rock | |[r] | | | | | | r| - | . |rock and earth | |[r] | | | | | | d| - | . |silt | |[r]breasting| | | | | | i| - | . | " | |[s] doors | | | | | | n| - | . |{silt, piles and} | |[s] doors | | | | | | a| | |{rip-rap. } | |[r]breasting| | | | | | r| - | . |silt | |[s] doors | | | | | | y| - | . | " | |[s] doors | | | | | | | - | . | " | |[s] doors. | | | | | | | - | , . | | | | | | | | | | - | , . | | | | | | | | | -+-----------+-------+------------------+---+------------+--+--+--+--+--| | - | . |silt | |[s] doors | | | | | | | - | . | " | |[s] " | | | | | | h| - | . | " | |[s] ½ " | | | | | | e| - | . | " | |[s] door | | | | | | a| - | . | " | |[s] " | | | | | | v| - , | . | " | |[s] " | | | | | | y| , - , | . | " | |[s] " | | | | | | | , - , | . | " | |[s] " | | | | | | | , - , | . | " | |[s] " | | | | | | | - , | , . | | | | | | | | | -+-----------+-------+------------------+---+------------+--+--+--+--+--| a| - , | , . | | | | | | | | | l| - , | , . | | | | | | | | | l| | | | | | | | | | | =+===========+=======+==================+===+============+==+==+==+==+==| table part =+===========+====+=====+=====+========+====+====+====+====+====| w| | | |av. | | time for ring | e| | | | | | erection, | i| | | |time | | hrs. and min. | g| |----+-----| | |----+----+----+----+----| h| |av. |time |per | | | | | | | t| |no. |muck-| |t | o | | | | | | |of |ing, |ring,|i | r | | | | | o| |cu. |per | |m | d | b | b | | | f| |yd. |cu. |shov-|e j | i | o | o | t | | | |per |yd. |ing | a | n | r | r | a | m | | |ring| | |f c | a | e | e | p | e | i| | | |and |o k | r | | | e | a | r| section | | | |r s | y | | | r | n | o| between |----| |muck-+--------+----+----+----+----+----| n| rings | e | |ing | f | g | g | g | g | g | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | | - | - |time for| - | | | - | - | | - | | - | - |jacks | - | | | - | - | o| - | | - | - |for | - | | | - | - | r| - | | - | - |light | - | j | j | - | - | d| - | | - | - |iron is | - | - | - | - | - | i| - | | - | - |included| - | - | - | - | - | n| - | | - | - |in | - | - | - | - | - | a| | | | |shoving | | | | | | r| - | | - | - |and | - | - | - | - | - | y| - | | - | - |mucking | - | - | - | - | - | | - | | - | - | | - | - | - | - | - | | - | | - | - | [t] | - | - | - | - | - | | - | | - | - | [t] | - | | | - | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | | - | - | - | - | - | - | - | - | | - | | - | - | - | - | - | - | - | - | | - | | - | - | - | - | - | - | - | - | h| - | | - | - | - | - | - | - | | - | e| - | | - | - | - | - | - | - | | - | a| - , | | - | - | - | - | - | - | - | - | v| , - , | | - | - | - | - | - | - | - | - | y| , - , | | - | - | - | - | - | - | | - | | , - , | | - | - | - | - | - | - | - | - | | - , | | - | - | [t] | - | - | - | - | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| a| - , | | - | - | [t] | - | - | - | - | - | l| - , | | - | - | [t] | - | | | - | - | l| | | | | | | | | | | =+===========+====+=====+=====+========+====+====+====+====+====| table part =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| w| | bolting time, whole |time| | e| | time on bolts after | | | i| | ring is complete. |lost| total time. | g| |----+----+----+----+----| |-----+-----+-----+-----+-----| h| | | | | | |re- | | | | | | t| | o | | | | |pair- | | | | | | | r | | | | |ing | | | | | | o| | d | b | b | | | | o | | | | | f| | i | o | o | t | |hy- | r | | | | | | | n | r | r | a | m |drau- d | b | b | | | | | a | e | e | p | e |lic | i | o | o | t | | i| | r | | | e | a | | n | r | r | a | m | r| section | y | | | r | n |pip-| a | e | e | p | e | o| between |----+----+----+----+----|ing | r | | | e | a | n| rings | h | h | h | h | h | | y | | | r | n | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| | - |}excavation partially {| | - | | | - | - | | - |}completed previously. {| | - | | | - | - | o| - |} {| - | - | | | - | - | r| - |} {| - | - | | | - | - | d| - |}bolting time for light{| - | - | - | - | - | - | i| - |}iron is included in {| - | - | - | - | - | - | n| - |}erection. {| - | - | - | - | - | - | a| |} {| | | | | | | r| - |} {| - | - | - | - | - | - | y| - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | | | - | - | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| | - | - | - | - | - | - | - | - | - | - | - | - | | - | - | - | - | - | - | - | - | - | - | - | - | | - | - | - | - | - | - | - | - | - | - | - | - | h| - | - | - | - | | - | - | - | - | - | | - | e| - | - | - | - | | - | - | - | - | - | | - | a| - , | - | - | - | - | - | - | - | - | - | - | - | v| , - , | - | - | - | - | - | | - | - | - | - | - | y| , - , | - | - | - | | - | | - | - | - | | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | - , | - | - | - | - | - | - | - | - | - | - | - | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| a| - , | [u]| | | | | - | - | - | - | - | - | l| - , | [u]| | | | | - | -- | | | - | - | l| | | | | | | | | | | | | =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| table summary part ===+===========+=======+==============+====+============+==+==+===+==+==| | | | ave. no. | w| | | of men | e| | description | in gang | i| |-------+--------------+----+------------+--+--+---+--+--| g| | | |ave.| | | | | | | h| | | |air | | | | | | | t| | | | | | | | | a| | | | | |p | | | d| g | i| | o| | | |r | | | r| r | r| | f| | | |e | | s| i| o | | | | | | |s | | h| l| u | t|t | i| | | |s | | i| l| t | r|o | r| section | | |u | | e| i| i | a|t | o| between |length | |r |method of | l| n| n | n|a | n| rings |in feet| material |e |excavation | d| g| g | s|l | ---+-----------+-------+--------------+----+------------+--+--+---+--+--| o {| - | . |rock | | [r] | | | | | | r {| - | . |rock and earth| | [r] | | | | | | d {| - | . |silt | |[r]breasting| | | | | | i {| | | | {|[s] doors | | | | | | n {| - | . |silt piles and| |[r]breasting| | | | | | a {| | |rip-rap | {|[s] doors | | | | | | r {| - | . |silt | |[s] doors | | | | | | y {|-----------+-------+--------------+----+------------+--+--+---+--+--| {| - | , . | | | | | | | | | {|-----------+-------+--------------+----+------------+--+--+---+--+--| {| - | , . | | | | | | | | | ---+-----------+-------+--------------+----+------------+--+--+---+--+--| hvy| - , | , . | | |[s] door | | | | | | ---+-----------+-------+--------------+----+------------+--+--+---+--+--| all| - , | , . | | | | | | | | | ===+===========+=======+==============+====+============+==+==+===+==+==| table summary part ===+========+========+=======+=====+====+=====+==================+=======| w | | | | unavoidable delays | e | | | average time | (not included in average | i o| | | per ring. | time per ring). | g f| | |-------+-----+----+-----+------------------+-------| h |average | time | | | | | | | t i| no. of |mucking,|shoving| | | | | | r| cubic | per | and |erec-| | | | | o| yards | cubic |mucking|tion |lost| | | time | n|per ring| yard | [t] | [u] |time|total|items |hrs min| ---+--------+--------+-------+-----+----+-----+------------------+-------| o {| | - | - | - | | - |first bulkhead | | r {| | - | - | - | - | - |second bulkhead | | d {| | - | - | - | - | - |grouting | | i {| | | | | | | | | n {| | - | - | - | - | - |blowout | | a {| | | | | | | | | r {| | - | - | - | - | - |waiting-heavy iron| | y {|--------+--------+-------+-----+----+-----+------------------+-------| {| | - | - | - | - | - |total | | {|--------+--------+-------+-----+----+-----+------------------+-------| {| | - | - | - | - | - |per ring | | ---+--------+--------+-------+-----+----+-----+------------------+-------| hvy| | - | - | - | - | - | | | ---+--------+--------+-------+-----+----+-----+------------------+-------| all| | - | - | - | - | - | | | ===+========+========+=======+=====+====+=====+==================+=======| [r] excavating ahead of shield. [s] shoving shield into silt with ... doors open. [t] including time for jacks. [u] including bolting time. table .--shield-driven tunnel work, weehawken shaft, river tunnel north. table showing the size of the gang, the amount of excavation, and the time per ring taken for the various operations involved in building tunnel through the several kinds of ground encountered; also the extent and nature of all the unavoidable delays. table part =+===========+=======+=================+===+============+==+===+===+==+==| w| | | ave. no. | e| | | of men | i| | description | in gang | g| |-------+- ------------- +---+------------+--+---+---+--+--| h| | | |ave| | | | |a | | t| | | |air| | |d |g |i | | | | | | | | |r |r |r | | o| | | |p | |s |i |o | | | f| | | |r | |h |l |u |t |t | | | | |e | |i |l |t |r |o | | | | |s | |e |i |i |a |t | i| | | |s | |l |n |n |n |l | r| section | | |u | |d |g |g |s |e | o| between | length| |r |method of |--+---+---+--+--| n| rings |in feet|material |e |excavation |a |b |c |d | | -+-----------+-------+-----------------+---+------------+--+---+---+--+--| | - | . |rock | |[x] | |. | | | | | - | . | " | |[x] | | | . | | | | - | . |mixed sand and | |[x]breasting| | |. | | | o| | |rock | | | | | | | | r| - | . |sand and gravel | |[x] " | | | . | | | d| - | . |sand and silt | {|[x]breasting| | |. | | | i| | |with piles | {|and cutting}| | | | | | n| - | . |silt and piles | {|piles }| | |. | | | a| - | . |silt | |[y] doors | | | | | | r| - | . | " | | | | | | | | y| - | . | " | |[y] doors | | | | | | | - | . | " | | | | | | | | | - | . | " | |[y] doors | | | | | | | - | . | " | | | | | | | | | - | . | " | |[y] doors | | | | | | | - | . | " | | " | | | | | | | - | . | " | | " | | | | | | | - | . | " | | " | | | | | | | - | . | " | | " | | | | | | | - | , . | | | | | | | | | | - | , . | | | | | | . | | | -+-----------+-------+-----------------+---+------------+--+---+---+--+--| | - | . |silt | |[y] doors | | | | | | | - | . | " | |[y] " | | | | | | | - | . | " | |[y] " | | | | | | | - | . | " | |[y] " | | | | | | h| - | . | " | |[y] " | | | | | | e| - | . | " | |[y] " | | | | | | a| - | . | " | |[y] " | | | | | | v| - | . | " | |[y] " | | | | | | y| - , | . | " | |[y] " | | | | | | | , - , | . | " | |[y] " | | | | | | | , - , | . | " | |[y] " | | | | | | | - , | , . | | | | | | | | | -+-----------+-------+-----------------+---+------------+--+---+---+--+--| a| - , | , . | | | | | | . | | | l| - , | , . | | | | | . | . | | | l| | | | | | | | | | | =+===========+=======+=================+===+============+==+===+===+==+==| table part =+===========+====+=====+=====+========+====+====+====+====+====| w| | | |av. | | time for ring | e| | | | | | erection, | i| | | |time | | hrs. and min. | g| |----+-----| | |----+----+----+----+----| h| |av. |time |per | | | | | | | t| |no. |muck-| |t | s | | | | | | |of |ing, |ring,|i | t | | | | | o| |cu. |per | |m | r | b | b | | | f| |yd. |cu. |shov-|e j | a | o | o | t | | | |per |yd. |ing |a | i | r | r | a | m | | |ring| | |f c | g | e | e | p | e | i| | | |and |o k | h | | | e | a | r| section | | | |r s | t | | | r | n | o| between | | |muck-+--------+----+----+----+----+----| n| rings | e | |ing | f | g | g | g | g | g | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | | - | - |time | - | | | | - | | - | | - | - |for | - | | | - | - | o| - | | - | - |jacks | - | | | - | - | o| | | | |for | | | | | | r| - | | - | - |light | - | | | - | - | d| - | | - | - |iron is | - | j | j | - | - | i| | | | |included| | | | | | n| - | | - | - |in | - | - | - | - | - | a| - | | - | - |shoving | - | - | - | - | - | r| - | | | - |and | - | - | - | | - | y| - | | - | - |mucking.| - | - | - | - | - | | - | | | - | | - | - | - | - | - | | - | | - | - | | - | - | | - | - | | - | | | - | | - | - | - | - | - | | | | | | | | | | | | | - | | - | - | | - | - | - | - | - | | - | | - | - | | - | - | - | - | - | | - | | - | - | | - | - | - | - | - | | - | | - | - | | - | - | - | - | - | | - | | - | - | | - | - | - | - | - | | - | | | | | | | | | | | - | | - | - | | - | - | - | - | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | | - | - | [v] | - | - | - | - | - | | - | | - | - | - | - | - | - | - | - | | - | | - | - | - | - | - | - | - | - | | - | | - | - | - | - | - | - | - | - | h| - | | - | - | - | - | - | - | - | - | e| - | | - | - | - | - | - | - | - | - | a| - | | - | - | - | - | - | - | - | - | v| - | | - | - | - | - | - | - | | - | y| - , | | - | - | - | - | - | - | | - | | , - , | | - | - | - | - | - | - | - | - | | , - , | | - | - | - | - | - | - | - | - | | - , | | - | - | - | - | - | - | - | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| a| - , | | - | - | [v] | - | - | - | - | - | l| - , | . | - | - | [v] | | | | | - | l| | | | | | | | | | | =+===========+====+=====+=====+========+====+====+====+====+====| table part =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| w| | bolting time, whole |time| | e| | time on bolts after | | | i| | ring is complete. |lost| total time. | g| |----+----+----+----+----| |-----+-----+-----+-----+-----| h| | | | | | |re- | | | | | | t| | s | | | | |pair- | | | | | | | t | | | | |ing | | | | | | o| | r | b | b | | | | s | | | | | f| | a | o | o | t | |hy- | t | | | | | | | i | r | r | a | m |drau- r | b | b | | | | | g | e | e | p | e |lic | a | o | o | t | | i| | h | | | e | a | | i | r | r | a | m | r| section | t | | | r | n |pip-| g | e | e | p | e | o| between |----+----+----+----+----|ing | h | | | e | a | n| rings | h | h | h | h | h | | t | | | r | n | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| | - | excavation partially | | - | | | | - | | - |} completed previously.{| | - | | | - | - | | - |} {| - | - | | | - | - | o| - |} {| - | - | | | - | - | r| - |} {| - | - | | | - | - | d| - |} {| - | - | - | - | - | - | i| |} {| | | | | | | n| - |} bolting time for {| - | - | - | - | - | - | a| - |} light iron is {| | - | - | - | | - | r| - |} included in {| | - | - | - | - | - | y| - |} erection. {| | - | - | - | - | - | | - |} {| - | - | - | | - | - | | - |} {| - | - | - | - | - | - | | |} {| | | | | | | | - |} {| - | - | - | - | - | - | | - |} {| | - | - | - | - | - | | - |} {| | - | - | - | - | - | | - |} {| | - | - | - | - | - | | - |} {| | - | - | - | - | - | | - |} {| | | | | | | | - |} {| - | - | - | - | - | - | -+-----------+------------------------+----+-----+-----+-----+-----+-----| | - | - | - | - | - | - | | - | - | - | - | - | | - | - | - | - | - | - | - | - | - | - | - | - | | - | - | - | - | - | - | - | - | - | - | - | - | h| - | - | - | - | - | - | | - | - | - | - | - | e| - | - | - | - | - | - | - | - | - | - | - | - | a| - | - | - | - | - | - | - | - | - | - | - | - | v| - | - | - | - | - | - | - | - | - | - | - | - | y| - | - | - | - | | - | | - | - | - | | - | | - , | - | - | - | | - | | - | - | - | | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | - , | - | - | - | - | - | - | - | - | - | - | - | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| a| - , |[w] | | | | | - | - | - | - | - | - | l| - , |[w] | | | | | - | | | | | - | l| | | | | | | | | | | | | =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| table summary part ===+===========+=======+==============+====+============+==+===+===+==+==| | | | ave. no. | w| | | of men | e| | description | in gang | i| |-------+--------------+----+------------+--+---+---+--+--| g| | | |ave.| | | | | | | h| | | |air | | | | | | | t| | | | | | | | | a| | | | | |p | | | d | g | i| | o| | | |r | | | r | r | r| | f| | | |e | | s| i | o | | | | | | |s | | h| l | u | t|t | i| | | |s | | i| l | t | r|o | r| section | | |u | | e| i | i | a|t | o| between |length | |r |method of | l| n | n | n|a | n| rings |in feet| material |e |excavation | d| g | g | s|l | ---+-----------+-------+--------------+----+------------+--+---+---+--+--| o {| - | . |rock | | [x] | |. | | | | r {| - | . | " | | [x] | | | . | | | d {| - | . |mixed sand and| |[x]breasting| | |. | | | i {| | |rock | | | | | | | | n {| - | . |sand & gravel | |[x]breasting| | |. | | | a {| - | . |sand and silt | {|[x]breasting| | |. | | | r {| | |with piles | {|and cutting | | | | | | y {| - | . |silt w/ piles | {|piles | | |. | | | {| - | . |silt | |[y]doors | | | | | | {|-----------+-------+--------------+----+------------+--+---+---+--+--| {| - | , . | | |[y]doors | | . |. | | | ---+-----------+-------+--------------+----+------------+--+---+---+--+--| hvy| - , | , . | | | | | | | | | ---+-----------+-------+--------------+----+------------+--+---+---+--+--| all| - , | , . | | | | | . | . | | | ===+===========+=======+==============+====+============+==+===+===+==+==| table summary part ===+========+========+=======+=======+====+=====+===============+========| w | | | | unavoidable delays | e | | | average time |(not included in average| i o| | | per ring. | time per ring). | g f| | |-------+-------+----+-----+---------------+--------| h |average | time | | | | | | | t i| no. of |mucking,|shoving| | | | | | r| cubic | per | and | erec- | | | | | o| yards | cubic |mucking| tion |lost| | | time | n|per ring| yard | [v] | [w] |time|total| items |hrs min| ---+--------+--------+-------+-------+----+-----+---------------+--------| o {| | - | - | - | - | - |first bulkhead | - | r {| | - | - | - | - | - |second bulkhead| - | d {| | - | - | - | - | - |grouting | - | i {| | | | | | |old cave-in | - | n {| | - | - | - | - | - |shoving tube | - | a {| | - | - | - | - | - |---------------+--------| r {| | | | | | | total | - | y {| | - | - | - | - | - |---------------+--------| {| | - | - | - | - | - | per ring | - | {|--------+--------+-------+-------+----+-----+---------------+--------| {| | - | - | - | - | - | | | ---+--------+--------+-------+-------+----+-----+---------------+--------| hvy| | - | - | - | - | - | | | ---+--------+--------+-------+-------+----+-----+---------------+--------| all| . | - | - | - | - | - | | | ===+========+========+=======+=======+====+=====+===============+========| [v] including time for jacks. [w] including bolting time. [x] excavating ahead of shield. [y] shoving shield into silt with ... doors open. table .--shield-driven tunnel work, weehawken shaft, river tunnel south. table showing the size of the gang, the amount of excavation, and the time per ring taken for the various operations involved in building tunnel through the several kinds of ground encountered; also the extent and nature of all the unavoidable delays. table part =+===========+=======+============+====+============+==+==+===+===+==| w| | | ave. no. | e| | | of men | i| | description | in gang | g| |-------+------------+----+------------+--+--+---+---+--| h| | | |ave | | | | |a | | t| | | |air | | |d |g |i | | | | | | | | |r |r |r | | o| | | |p | |s |i |o | | | f| | | |r | |h |l |u |t |t | | | | |e | |i |l |t |r |o | | | | |s | |e |i |i |a |t | i| | | |s | |l |n |n |n |a | r| section | | |u | |d |g |g |s |l | o| between | length| |r |method of |--+--+---+---| | n| rings |in feet|material |e |excavation |a |b |c |d | | -+-----------+-------+------------+----+------------+--+--+---+---+--| | - | . |rock | |[c] {|excavation }| | | | | | {|partially }| | | | | | {|completed }| | | | | | {|previously. }| | - | . | " | |[c] | | | | | | | - | . |rock or | |[c] | | | | | | | | | | | | | | o| - | . |gravel and | |[c]breasting| | | | | | r| | |sand | | | | | | | | d| - | . |sand and | | " | | | | | | i| | |silt w/piles| | | | | | | | n| - | . |silt with | |top half | | | | | | a| | |piles | | r| - | . |silt | |[d] door | | | | | | y| - | . | " | |[d] door | | | | | | | - | . | " | |[d] doors | | | | | | | - | . | " | . |[d] " | | | | | | | - | . | " | . |[d] " | | | | | | | - | . | " | |[d] door | | | | | | | - | . | " | |[d] " | | | | | | | - | , . | | | | | | | | | | - | , . | | | | |. | . | . | | -+-----------+-------+------------+----+------------+--+--+---+---+--| | - | . |silt | |[d] door | | | | | | | - | . | " | |[d] doors | | | | | | | - | . | " | |[d] " | | | | | | h| - | . | " | |[d] " | | | | | | e| - | . | " | |[d] " | | | | | | a| - | . | " | |[d] " | | | | | | v| - | . | " | |[d] door | | | | | | y| - | . | " | |[d] " | | | | | | | - , | . | " | |[d] " | | | | | | | , - , | . | " | |[d] " | | | | | | | , - , | . | " | |[d] " | | | | | | | , - , | . | " | |[d] " | | | | | | | , - , | . | " | | | | | | | | | - , | , . | " | | | | | | | | -+-----------+-------+------------+----+------------+--+--+---+---+--| a| - , | , . | | | | | | | | | l| - , | , . | | | | | | | | | l| | | | | | | | | | | =+===========+=======+============+====+============+==+==+===+===+==| table part =+===========+====+=====+=====+========+====+====+====+====+====| w| | | |av. | | time for ring | e| | | | | | erection, | i| | | |time | | hrs. and min. | g| |----+-----| | |----+----+----+----+----| h| |av. |time |per | | | | | | | t| |no. |muck-| |t | o | | | | | | |of |ing, |ring,|i | r | | | | | o| |cu. |per | |m | d | b | b | | | f| |yd. |cu. |shov-|e j | i | o | o | t | | | |per |yd. |ing |a | n | r | r | a | m | | |ring| | |f c | a | e | e | p | e | i| | | |and |o k | r | | | e | a | r| section | | | |r s | y | | | r | n | o| between | | |muck-+--------+----+----+----+----+----| n| rings | e | |ing | f | g | g | g | g | g | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - |excavation| | | - | | | - | - | | | partially| | | | | | | | | | completed| | | | | | | | | |previously| | | | | | | | | - | . | - | - | | - | | | - | - | | - | . | - | - | | - | | | - | - | | | | | | | | | | | | o| - | . | - | - | | - | | | - | - | r| | | | | | | | | | | d| - | . | - | - | | - | j. | j. | - | - | i| | | | | | | | | | | n| - | . | - | - | | - | - | - | - | - | a| | | | | | | | | | | r| - | . | - | - | | - | - | - | - | - | y| - | | | - | | - | - | - | - | - | | - | . | - | - | | - | - | - | - | - | | - | | | - | | - | - | - | - | - | | - | . | - | - | | - | - | - | - | - | | - | . | - | - | | - | - | - | - | - | | - | | | - | | - | - | - | - | - | | - | . | - | - | [a] | - | - | - | - | - | | - | . | - | - | [a] | | | | | - | -+-----------+----+-----+-----+--------+----+----+----+----+----| | - | . | - | - | [a] | - | - | - | - | - | | - | . | | - | - | - | - | - | - | - | | - | . | - | - | - | - | - | - | - | - | h| - | . | - | - | - | - | - | - | - | - | e| - | . | - | - | - | - | - | - | | - | a| - | . | - | - | - | - | - | - | | - | v| - | . | - | - | - | - | - | - | - | - | y| - | . | - | - | - | - | - | - | | - | | - , | . | - | - | - | - | - | - | | - | | , - , | . | - | - | - | - | - | - | - | - | | , - , | . | - | - | - | - | - | - | - | - | | , - , | . | - | - | - | - | - | - | - | - | | , - , | . | - | - | - | - | - | - | - | - | | - , | . | - | - | - | - | - | - | - | - | -+-----------+----+-----+-----+--------+--- |----+----+----+----| a| - , | . | - | - | [a] | - | - | - | - | - | l| - , | . | - | - | [a] | | | | | - | l| | | | | | | | | | | =+===========+====+=====+=====+========+====+====+====+====+====| table part =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| w| | bolting time, whole |time| | e| | time on bolts after | | | i| | ring is complete. |lost| total time. | g| |----+----+----+----+----| |-----+-----+-----+-----+-----| h| | | | | | |re- | | | | | | t| | s | | | | |pair- | | | | | | | t | | | | |ing | | | | | | o| | r | b | b | | | | s | | | | | f| | a | o | o | t | |hy- | t | | | | | | | i | r | r | a | m |drau- r | b | b | | | | | g | e | e | p | e |lic | a | o | o | t | | i| | h | | | e | a | | i | r | r | a | m | r| section | t | | | r | n |pip-| g | e | e | p | e | o| between |----+----+----+----+----|ing | h | | | e | a | n| rings | h | h | h | h | h | | t | | | r | n | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| | - |} {| - | - | | | - | - | | |} {| | | | | | | | |} {| | | | | | | | |} {| | | | | | | | - |} {| - | - | | | - | - | | - |} {| - | - | | | - | - | | |} {| | | | | | | o| - |} {| - | - | | | - | - | r| |{ {| | | | | | | d| - |} {| - | - | j. | j. | - | - | i| |} {| | | | | | n| - |} bolting time for {| - | - | - | - | - | - | a| |} light iron is {| | | | | | | r| - |} included in {| - | - | - | - | - | - | y| - |} erection. {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | - | - | - | - | - | | - |} {| - | | | | | - | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| | - | - | - | - | - | - | - | - | - | - | - | - | | - | - | - | - | - | - | - | - | - | - | - | - | | - | - | - | - | - | - | - | - | - | - | - | - | h| - | - | - | - | - | - | - | - | - | - | - | - | e| - | - | - | - | | - | - | - | - | - | | - | a| - | - | - | - | | - | - | - | - | - | | - | v| - | - | - | - | - | - | - | - | - | - | - | - | y| - | - | - | - | | - | - | - | - | - | | - | | - , | - | - | - | | - | - | - | - | - | | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | , - , | - | - | - | - | - | - | - | - | - | - | - | | - , | - | - | - | - | - | - | - | - | - | - | - | -+-----------+----+----+----+----+----+----+-----+-----+-----+-----+-----| a| - , | [c]| | | | | - | - | - | - | - | - | l| - , | [c]| | | | | - | | | | | - | l| | | | | | | | | | | | | =+===========+====+====+====+====+====+====+=====+=====+=====+=====+=====| table summary part ===+===========+=======+==============+====+============+==+==+===+===+==| | | | ave. no. | w| | | of men | e| | description | in gang | i| |-------+--------------+----+------------+--+--+---+---+--| g| | | |ave.| | | | | | | h| | | |air | | | | | | | t| | | | | | | | | a | | | | | |p | | | d| g | i | | o| | | |r | | | r| r | r | | f| | | |e | | s| i| o | | | | | | |s | | h| l| u | t |t | i| | | |s | | i| l| t | r |o | r| section | | |u | | e| i| i | a |t | o| between |length | |r |method of | l| n| n | n |a | n| rings |in feet| material |e |excavation | d| g| g | s |l | ---+-----------+-------+--------------+----+------------+--+--+---+---+--| {| - | . |rock | |[b]breast | | | | | | o {| - | . |rock & gravel | | " | | | | | | r {| - | . |gravel & sand | | " | | | | | | d {| - | . |sand or silt, | | " | | | | | | i {| | | with piles | | | | | | | | n {| - | . |silt w/ piles | | " | | | | | | a {| - | . |silt | |[c] door | | | | | | r {| - | . | " | | " | | | | | | y {|-----------+-------+--------------+----+------------+--+--+---+---+--| {| - | , . | | | | |. | . | . | | ---+-----------+-------+--------------+----+------------+--+--+---+---+--| hvy| - , | , . |silt | | | | | | | | ---+-----------+-------+--------------+----+------------+--+--+---+---+--| all| - , | , . | | | | | | | | | ===+===========+=======+==============+====+============+==+==+===+===+==| table summary part ===+========+========+=======+======+====+=====+===============+========| w | | | | unavoidable delays | e | | | average time |(not included in average| i o| | | per ring. | time per ring). | g f| | |-------+------+----+-----+---------------+--------| h |average | time | | | | | | | t i| no. of |mucking,|shoving| | | | | | r| cubic | per | and | erec-| | | | | o| yards | cubic |mucking| tion |lost| | | time | n|per ring| yard | [z] | [a] |time|total| items |hrs min| ---+--------+--------+-------+------+----+-----+---------------+--------| {| . | - | - | - | - | - |first bulkhead | - | o {| . | - | - | - | - | - |second bulkhead| - | r {| . | - | - | - | - | - |grouting rock | - | d {| . | - | - | - | - | - | sections| | i {| | | | | | |blow-outs | - | n {| . | - | - | - | - | - |shield repairs | - | a {| . | - | - | - | - | - |horz. timbers | - | r {| . | - | - | - | - | - | total | , - | y {|--------+--------+-------+------+----+-----+---------------+--------| {| . | - | - | - | - | - |per ring | - | ---+--------+--------+-------+------+----+-----+---------------+--------| hvy| . | - | - | - | - | - | | | ---+--------+--------+-------+------+----+-----+---------------+--------| all| . | - | - | - | - | - | | | ===+========+========+=======+======+====+=====+===============+========| [z] including time for jacks. [a] including bolting time. [b] excavating ahead of shield. [c] shoving shield into silt with ... doors open. the average time taken for each operation at all the working faces is given in table . the work has been subdivided into the different kinds of ground encountered. the progress, as shown by the amount of work done each month by each shield, is given in table . table .--shield-driven tunnel work.--total number of rings erected and shifts worked by all four shields in contracts gy-west and gj, and the average size of gang, amount of excavation and time taken per ring for the various operations involved in building tunnel in each of the several kinds of ground encountered; also the extent and nature of all the unavoidable delays. table part ===+===================+=====+========+======+==+====+====+====+====+====| | | | | |a | ave. no. | w| | | | |v | of men | e| | | | | | in gang | i| | | | |a +----+----+----+----+----+ g| | | | |i | | | | a | | h| | | | |r | | d | g | i | | t| | | |total | | | r | r | r | | | | | | |p | s | i | o | | | o| |total| total |number|r | h | l | u | t | t | f| | | | |e | i | l | t | r | o | | description | no. | no. | of |s | e | i | i | a | t | i| | | | |s | l | n | n | n | a | r| of | of | of | -hour|u | d | g | g | s | l | o| | | | |r |----+----+----+----+----+ n| material |rings| feet. |shifts|e |unit|unit|unit|unit|unit| ---+-------------------+-----+--------+------+--+----+----+----+----+----+ {|rock. | | . | | | | | . | | | o {|rock and earth and | | . | | | | | . | | | r {| rock and gravel.| | | | | | | | | | d {|sand and gravel | | . | | | | | . | | | i {| (unobstructed), nj| | | | | | | | | | n {|sand and silt (with| | . | | | | | . | | | a {| piles.)| | | | | | | | | | r {|silt under r. r. | | . | | | | | | | | y {| tracks, ny| | | | | | | | | | {|rip-rap and silt | | . | | | | | | | | | under bulkhead.| | | | | | | | | | i {| |-----+--------+------+--+----+----+----+----+----| r {|total mixed and | | | | | | | | | | o {| difficult ground.| , | , . | , | | | | . | | | n {|-------------------+-----+--------+------+--+----+----+----+----+----+ {|silt--ordinary iron| , | , . | | | | | | | | ---+-------------------+-----+--------+------+--+----+----+----+----+----+ hvy|silt--heavy iron. | , | , . | | | | | | | | ---+-------------------+-----+--------+------+--+----+----+----+----+----+ |silt--ord and heavy| | | | | | | | | | |iron under river. | , | , . | , | | | | | | | |-------------------+-----+--------+------+--+----+----+----+----+----+ |grand total. | , | , . | , | | | | . | | | ===+===================+=====+========+======+==+====+====+====+====+====| table part ====+====+=======+========+=======+=======+=============+========| | | | | | | | | | | | | | | | | | | | | | | | ave. unavoidable | | | | delay per | | | average time per ring. | working face. | cu. |time|------------------------+-------+-------------+--------| yd. |per |shoving| | | | | time | per |cu. | and | | lost | | items |--------| ring|yd. |mucking|erecting| time | total |not included |ave unit| ----+----+-------+--------+-------+-------| in previous |--------| unit|unit|hrs min|hrs min |hrs min|hrs min| figures |hrs min | | | k | l | m | | | | ----+----+-------+--------+-------+-------+-------------+--------| | - | | | | | st bulkhead | | | - | | | | | d " | | | | | | | | | | | - | | | | |grouting | | | | | | | | | | | - | | | | |blow-outs | | | | | | | | | | | - | | | | |miscellaneous| | | | | | | | | | | - | | | | |total | | | | | | | | | | ----+----+-------+--------+-------+-------+-------------+--------| | | | | | | | | | - | | | | | | | ----+----+-------+--------+-------+-------+-------------+--------| | - | | | | | | | ----+----+-------+--------+-------+-------+-------------+--------| | - | | | | | | | ----+----+-------+--------+-------+-------+-------------+--------| | | | | | | | | | - | | | | | | | ----+----+-------+--------+-------+-------+-------------+--------| | - | | | | | | | ----+----+-------+--------+-------+-------+-------------+--------| average delay per ring-- hrs. min. average rings built by one shield = , ¼. average time per ring. hr min delays. min ----------- total time per ring. hr min note.--the "unavoidable delays" included in this table do not embrace the periods during which the work was at complete or partial standstill due to experiments and observations, shortage of iron due to change of design, and holidays. k-including time for jacks. l-including time spent by the whole gang on bolting; in addition to this there was a small gang which spent its whole time bolting. m-chiefly due to breakdowns of hydraulic lines and erector. _air pressure._--the air pressure varied from to lb. behind the river line it averaged lb. and under the river lb. behind the river lines the pressure was generally kept about equal to the water head at the crown, except where at weehawken, as previously described, this was impossible. in the silt the pressure was much lower than the hydrostatic head at the crown, but if it became necessary to make an excavation ahead of the shield, for example at the junction of the shields, the air pressure required was about equal to the weight of the overlying material, namely, the water and the silt, as the silt, which weighed from to lb. per cu. ft. and averaged lb. per cu. ft., acted like a fluid. table .--monthly progress of shield-driven tunnel work. =====+=============================+=============================+ | north manhattan. | south manhattan. | +-----------------------------+----------------------+------+ | number of | station |lin. | number of | station |lin. | | rings | of |ft. | rings | of |ft. | | erected. | leading |for | erected. | leading |for | +-----------+ ring. |month.+-----------+ ring. |month.| |for | to | | |for |to | | | month|month|date | | |month|date | | | -----+-----+-----+----------+------+-----+-----+----------+------+ | | | | | | | | | may | | | + . | . | | | | | june | | | + . | . | | | | | july | | | + . | . | | | | | aug | | | + . | . | | | | | sept | | | + . | . | | | + . | . | oct | | | + . | . | | | + . | . | nov | | | + . | . | | | + . | . | dec | | | + . | . | | | + . | . | | | | | | | | | | jan | | | + . | . | | | + . | . | feb | | | + . | . | | | + . | . | mar | | | + . | . | | | + . | . | april| | | + . | . | | | + . | . | may | | | + . | . | | | + . | . | june | | | + . | . | | | + . | . | july | | , | + . | . | | | + . | . | aug | | , | + . | . | | | + . | . | sept | | , | + . | . | | , | + . | . | oct | | | | | | , | + . | . | nov | | | | | | , | + . | . | =====+=====+=====+==========+======+=====+=====+==========+======+ =====+=============================+============================+======== | north weehawken. | south weehawken. | +-----------------------------+----------------------------+average | number of | station |lin. | number of | station |lin. |progress | rings | of |ft. | rings | of |ft. |per | erected. | leading |for | erected. | leading |for |shield +-----------+ ring. |month.+-----------+ ring. |month|lin. ft. |for | to | | |for |to | | |per month|month|date | | |month|date | | |month. -----+-----+-----+----------+------+-----+-----+----------+-----+-------- | | | | | | | | | may | | | | | | | | | . june | | | + . | . | | | + . | . | . july | | | + . | . | | | + . | . | . aug | | | + . | . | | | + . | . | . sept | | | + . | . | | | + . | . | . oct | | | + . | . | | | + . | . | . nov | | | + . | . | | | + . | . | . dec | | | + . | . | | | + . | . | . | | | | | | | | | jan | | | + . | . | | | + . | . | . feb | | | + . | . | | | + . | . | . mar | | | + . | . | | | + . | . | . april| | | + . | . | | | + . | . | . may | | | + . | . | | | + . | . | . june | | | + . | . | | | + . | . | . july | | | + . | . | | | + . | . | . aug | | , | + . | . | | , | + . | . | . sept | | , | + . | . | | , | + . | . | . oct | | , | + . | . | | , | + . | . | . nov | | , | + . | . | | | | | . -----+-----+-----+----------+------+-----+-----+----------+-----+-------- a ½-in. air line was taken direct from the working chamber to the recording gauges in the engine-room, which enabled the engine-room force to keep a constant watch on the air conditions below. to avoid undue rise of pressure, a safety valve was set on the air line at each lock, set to blow off if the air pressure rose above that desired. the compressor plant was ample, except, as before described, when passing the gravel section at weehawken. records were kept of the air supply, and it may be said here that the quantity of free air per man per hour was in general between , and , cu. ft., though in the open gravel where the escape was great it was for a time as much as , cu. ft. for more than half the silt period it was kept between , and , cu. ft., but when it seemed proved beyond doubt that any quantity more than , cu. ft. had no beneficial effect on health, no attempt was made to deliver more, and on two separate occasions for two consecutive weeks it ran as low as , cu. ft. without any increase in the number of cases of bends. the amount of co_{ } in the air was also measured daily, as the specifications called for not more than part of co_{ } per , parts of air. the average ranged between . and . parts per , , though in exceptional cases it fell as low as . and rose to . . the air temperature in the tunnels usually ranged from ° to ° fahr., which was the temperature also of the surrounding silt, though at times, in the earlier parts of the work when grouting extensively in long sections of the tunnel in rock, it varied from ° to ° fahr. _grouting._--grout of one part of portland cement to one part of sand by volume was forced outside the tunnel lining by air pressure through ½-in. tapped and plugged grout holes formed in each segment for this purpose, wherever the ground was not likely to squeeze in upon the metal lining as soon as this was erected. that is to say, it was used everywhere up to the river line; between river lines it was not used except at the new york bulkhead wall in order to fill voids in the rip-rap, and at the point of junction of the shields where the space between the metal lining and the shield skins outside it was grouted. cow bay sand was used, and it had to be screened to remove particles greater than / in. in diameter, which would choke the valves. for later grouting work, namely, in the top of the concrete lining inside the metal lining, rockaway beach sand was used. this is very fine, and did not need screening; it cost more, but the saving of screening and the non-blocking of valves, etc., resulted in a saving. the grout was mixed in a machine shown in fig. , plate xli, which is a view of the grouting operation. the grout pipes were not screwed directly into the tapped hole in the segments, but a pipe containing a nipple and valve was screwed into the grout hole and the grout pipe screwed to the pipe. this prevented the waste of grout, enabled the valve to be closed and the grout pipe disconnected, and the pipe to be left in position until the grout had set. in the full rock section, or rings were put in without grouting; then the shield was stopped, the last two or three rings were detached and pulled ahead by the shield, a masonry stop-wall was built around the outside of the last ring left in, and the whole or rings were grouted at one time. in the landward silt and gravel each ring had to be grouted as soon as the shield had left it, in order to avoid the flattening caused by the weight coming on the crown while the sides were as yet unsupported. the grout was prevented from reaching the tail of the shield by plugging up the space with empty cement bags, assisted by segmental boards held against the face of the leading ring by u-shaped clamps, fitting over the front circumferential flange of the ring and the boards, and tightened by wedges. the air pressure varied between and lb. per sq. in. above normal. the force consisted of one pipe-fitter and one or two laborers employed part of their time. when a considerable length was being grouted at a time, as in the full rock section, many laborers were employed for a short period. transportation and disposal. the transportation and disposal will be described under the following headings: receipt and unloading of materials, surface transportation, tunnel transportation, disposal. _receipt and unloading of materials._--at the manhattan shaft the contractor laid a spur siding into the yard from the freight tracks of the new york central railroad, which immediately adjoins the yard on the west. there was also wharfage on the river front about , ft. away. at the weehawken shaft there were four sidings from the erie railroad and one from the west shore railroad. access to the river was gained by a trestle direct from the yard, and baldwin avenue adjoined the yard. all the iron lining arrived by railroad. it was unloaded by derricks, and stacked so that it was convenient for use in the tunnel. the manhattan derricks were a pair of steel ones with -ft. booms, worked by a -h.p., -volt, electric motor. there was also a stiff-leg derrick with -ft. boom, on a platform near the shaft, which was worked by a -h.p., -volt motor. at weehawken there were two -ft. boom, stiff-leg derricks of tons capacity, one worked by a -h.p. lidgerwood boiler and engine, and the other by a -h.p., -volt, electric motor. these derricks were set on elevated trestles near the erie railroad sidings. there was a -ft. stiff-leg derrick with a -h.p. lidgerwood boiler and engine near the cement warehouse on the west shore railroad. the storage area for iron lining was , sq. ft. at manhattan and , sq. ft. at weehawken; the maximum quantity of lining in storage at any one time was rings at manhattan and , rings at weehawken. the cement, which was issued and sold by the company to the contractor, was kept in cement warehouses; that at the new york side was at eleventh avenue and th street, or some , ft. from the shaft, to which it was brought by team; that at weehawken was adjacent to the shaft, with a -ft. gauge track throughout it and directly connected with the shaft elevator. _surface transportation._--in the early days the excavation was handled in scale-boxes of cu. yd. capacity which were hoisted up the shafts by a derrick, but, when the iron period began, two-cage elevators were put in at each shaft. they were worked by a single, friction-drum, lidgerwood, steam hoisting engine of h.p. all materials of construction were loaded on cars on the surface at the point where they were stored, and hauled on these to the elevators, sent down the shaft, and taken along the tunnels to the desired point without unloading. the narrow-gauge railway on the surface and in the tunnel was of -ft. gauge with -lb. rails. about flat cars and mining cars were used at each shaft. on the surface at manhattan these were moved by hand, but at weehawken, where distances were greater, two electric locomotives on the overhead trolley system were used. _tunnel transportation._--the mining cars shown in fig. were of ¼ cu. yd. capacity. the short wheel base and unbalanced loading caused a good many upsets, but they were compact, easily handled, and could be dumped from either side or end. [illustration: muck car (as used in river tunnels) capacity , lbs. or ¼ cu. yd. fig. .] the flat cars shown in fig. were of tons capacity, and could hold two tunnel segments. as the working face was down grade from the shafts, the in-bound cars were run by gravity. for out-bound cars a cable haulage system was used, consisting of double-cylinder, lidgerwood, single friction-drum, hoisting engines (no. ) of h.p., with cylinders in. in diameter and in. stroke and drums in. in diameter. these were handily moved from point to point, but, as there was no tail rope, several men had to be used to pull the cable back to the face. after the second air-lock bulkhead walls had been built, a continuous-cable system, worked electrically, was put in each tunnel between the first and second air-locks. the engine consisted of an electric motor driving a -ft. -in. drum hoist around which a ¾-in. steel wire cable passed three times. the cable was led around a sheave, down the tunnel on the right side of the in-bound track, and returned on the left side of the out-bound track. it was then carried around a set of sheaves, where a tension of , lb. was supplied by a suspended weight which acted on a sheave with a sliding axle on the tension carriage. the cable was supported throughout its length on -in. pulleys set in the floor at -ft. intervals. all the guide sheaves were in. in diameter. [illustration: flat car for tunnel segments capacity , lbs. fig. .] each car was attached to the cable by a grip at its side. this was fastened and unfastened by hand, but was automatically released just before reaching the turn in the cable near each lock. this system could haul without difficulty an unbalanced load of muck cars, spaced ft. apart, up a % grade. the cable operated over about , ft. of tunnel, the motor being placed at the top of the grade. the driving motor was of the semi-armored, -pole, series-wound type, rated at h.p., rev. per min., and using direct current at volts. the speed of handling the cars was limited by their having to pass through the air-locks on a single track. as many as cars have been hauled each way in one -hour shift. _disposal._--at manhattan the tunnel muck was carried from the elevator over the upper level of the yard trestle and dumped into bins on the d street side, whence it was teamed to the public dump at th street and north river. at weehawken the rock excavation was removed by the erie railroad on flat cars on which it was dumped by the tunnel contractor, but all the silt muck was teamed away to some marshy ground where dumping privileges were obtained. the typical forces employed on transportation were as follows: _receipt and unloading of material: surface transportation and disposal._ at manhattan shaft, on -hour shifts: engineers on derricks. @ $ . per day. foremen. " . " " laborers loading and unloading iron. " . " " laborers on disposal. " . " " teams. " . " " at weehawken shaft, on -hour shifts: engineers on derricks and locomotives. @ $ . per day. laborers loading and unloading iron. " . " " foremen. " . " " laborers on disposal. " . " " teams on disposal. " . " " tunnel transportation (including shaft elevator): shaft elevators and to and from the first air-lock on -hour shift: engineers. @ $ . per day. signalmen. " . " " foreman. " . " " laborers. " . " " between first lock and working face, on -hour shifts, the force varied: from to (average ) hoist engineers @ $ . per day. from to (average ) lockman " . " " from to (average ) trackmen " . " " from to (average ) cablemen (pulling back cable) " . " " _pumping._--the water was taken out of the invert by a -in. blow-pipe which was always kept up to a point near the shield and discharged into the sump near the shaft. when the air pressure was removed and the blow-pipe device, consequently, was unavailable, small cameron pumps, driven by compressed air, and having a capacity of about gal. per hour, were used, one being set up wherever it was necessary to keep the invert dry; for example, at points where caulking was in progress. _lighting._--the tunnels were lighted by electricity, the current being supplied, at a pressure of volts, from the dynamos in the contractor's power-house. two wire cables were used as far as the second air-locks, about , ft. from the power-house, on each side; and beyond that point, to the junction of the shields (about , ft.), and wires were used. these cables also carried the current for the cable haulage system. two rows of -c.p. lamps, provided with reflectors, were used in each tunnel; one row was along the side just above the axis, with the lights at about -ft. intervals; the other along the crown, with the lamps halfway between the side lamps, also at -ft. intervals. at points where work was in progress three groups of lights each were used. the tunnels as a whole were well lighted, and in consequence work of all kinds was much helped. _period no. ._--_caulking and grummeting._--_november, , to june, ._--after the metal lining had been built completely across the river in both tunnels, the work of making it water-tight was taken up. this consisted in caulking into the joints between the plates a mixture of sal-ammoniac and iron borings which set up into a hard rusty mass, and in taking out each bolt and placing around the shank under the washer at each end a grummet made of yarn soaked in red lead. these grummets were made by the contractor on the works, and consisted of three or four strands of twisted hemp yarn, known as "lath yarn," making up a rope-like cross-section about ¼ in. in diameter. usually, one of these under each washer was enough, but in wet gravel, or where bolts were obliquely in the bolt-holes, two were used at each end. after pulling the grummets in, all the nuts were pulled up tight by wrenches about ft. long, with two men on one wrench. bolts were not passed as tight unless the nut resisted the weight of an average man on a ½-ft. wrench. before putting in the caulking mixture, the joints were carefully scraped out with a special tool, cleaned with cotton waste, and washed with a stream of water. the usual mixture for sides and invert was about lb. of sal-ammoniac and lb. of sulphur to lb. of iron filings or borings. in the arch, lb. of sal-ammoniac and lb. of sulphur to lb. of filings was the mixture. a small hand-hammer was used to drive the caulking tool, but, in the sides and invert, air hammers were used with some advantage. the success of work of this kind depends entirely on the thoroughness with which the mixture is hammered in; and the inspection, which was of an exceedingly monotonous nature, called for the greatest care and watchfulness on the part of the company's forces, especially in the pocket iron, where each bolt had to be removed, the caulking done at the bottom of the pockets put in, the bolts replaced; and the rest of the pockets filled. the results have been satisfactory, as the leakage under normal air and prior to placing the concrete averaged about . gal. per lin. ft. of tunnel per hours, which is about . gal. per lin. ft. of joint per hours. with each linear foot of joint is included the leakage from . bolts. afterward, when the concrete lining was in, the leakage was found to be about . to . gal. per lin. ft. of tunnel per hours, which compares favorably with the records of other lined tunnels. the typical gang employed on this work was as follows: _in pocket iron:_ general foreman @ $ . per day. mixer " . " " nipper " . " " caulkers " . " " grummeters " . " " _in pocketless iron:_ general foreman @ $ . per day. mixer " . " " nipper " . " " caulkers " . " " grummeters " . " " the average amount of caulking and grummeting done per shift with such a gang was (with pocketless grooves), lin. ft. of joint and bolts grummeted; and in pocket iron: lin. ft. of joint and bolts grummeted. the caulking and grummeting work was finished in june, , this completing the second period. _period no. ._--_experiments, tests, and observations._--_april, , to april, ._--the third period, that of tests and observations in connection with the question of foundations, is dealt with in another paper. it occupied from april, , to november, . the results of the information then gathered was that it was not thought advisable to go on with the foundations. _period no. ._--_capping pile bores, sinking sumps, and building cross-passages._--_april, , to november, ._--in order to reduce the leakage from the bore segments to the least possible amount before placing the concrete lining, it was decided to remove the plugs and replace them with flat cover-plates; these have been described before, together with the filling of bore segments no. with mortar to reduce the leakage around the distance piece. during this period the turnbuckles to reinforce the broken plates were put in, and the sump sunk at the lowest point of the tunnel. these sumps have been described in a previous part of this paper; they were put down without trouble. as much as possible of the concrete lining was put in before the lining castings were taken into the tunnel, as the space inside was very restricted. the first lining casting was bolted to the flat flanges of the sump segment, the bolts holding the latter to the adjacent segments were removed, and the whole was forced down with two of the old shield jacks, taking a bearing on the tunnel. the two together exerted a pressure of about tons. the plugs in the bottom of the sump segment were taken out, and pipes were put in, through which the silt squeezed up into the tunnel and relieved the pressure on the sump segment. if the silt did not flow freely, a water-jet was used. the sump was kept plumb by regulating the jacks. in this way the sump was sunk, adding lining sections one by one, and finally putting on the top segment, which was composed of three pieces. the time taken to sink one sump was about days, working one -hour shift per day, and not counting the time taken to set up the jacks and bracing. the sinking of each section took from to hours. the air pressure was lb. and the hydrostatic head lb. per sq. in. the force was assistant superintendent at $ . per day, foreman at $ . , and laborers at $ . per day. _cross-passages._--it was during this period that the five cross-passages previously mentioned were built. in the case of those in the rock, careful excavation was needed so as to avoid breaking the iron lining. drilling was done from both ends, the holes were closely spaced, and about ft. in. deep, and light charges of powder were used. the heading, by ft. in cross-section, was thus excavated in five lengths, with holes to a length, and about lin. ft. of hole per yard. about . lb. of powder per cu. yd. was used. the sides, top, and bottom were then drilled at a very sharp angle to the face and the excavation was trimmed to the right size. this widening out took about ½ ft. of hole per cu. yd., and . lb. of powder. in the passages in silt the excavation had to be ft. wide and ft. in. high to give enough room inside the timbers. the plates at one end of the passage were first removed. an air pressure of lb. was carried, which was enough to keep the silt from squeezing in and yet left it soft enough to be chopped with a spade. a top heading, of full width and ft. in. high, was first taken out, and the roof was sheathed with -in. boards held by by -in. head trees at -ft. centers, with by -in. side trees. the lower ft. of bench was then taken out, a tight floor of by -in. cross-timber was put in, and also longer side trees, the head trees being temporarily held by two longitudinal by -in. stringers blocked in place. the bulk of the space between the side trees was filled with by -in. posts and blocking. the plates at the other end of the passage were then taken out from the other tunnel. after the excavation was out, the outer reinforced concrete lining was built. rough forms were used, as the interior surfaces of the passages were to be rendered with a water-proofing cement. a few grout pipes were built in, and all voids outside the concrete were grouted. grouting was also done through the regular grout holes of the metal lining around the openings. in the case of the most westerly of the cross-passages at weehawken, which was in badly seamed rock carrying much water, a steel inter-lining, rather smaller than the concrete, was put in. the space between the concrete and the steel was left open, so that water coming through the concrete lining was stopped by the steel plate. this water was led back to the shield chamber in a special drain laid in the bench of the river tunnel and behind the ducts. from the shield chamber the water ran with the rest of the drainage from the weehawken land tunnels to the weehawken shaft sump. [illustration: typical cross-sections showing successive stages in placing concrete in river tunnels fig. .] _period no. ._--_placing the concrete lining._--_november, , to june, ._--during the fifth period the concrete lining was put in. this lining was placed in stages, as follows: first, the invert; second, the duct bench; third, the arch; fourth, the ducts; and fifth, the face of the bench. this division can be seen by reference to fig. . all the work was started on the landward ends and carried toward the middle of the river from both sides. except where the weehawken force passed the lowest point of the tunnel, which is at station or nearly ft. to the west of the middle of the river, all the work was down grade. before any concrete was placed, the surface of the iron was cleaned with scrapers and wire brushes, and washed with water. any leaks in the caulking and grummeting (finished by june, , and therefore all more than months old) were repaired. all the grout hole plugs were examined, and the plugs in any leaking ones were taken out, smeared with red lead, and replaced. the leakage in the caulking was due to the fact that the tunnel had been settling slightly during the whole months of pile tests, and, therefore, had opened some of the joints. after the caulking had been repaired and the surface thoroughly cleaned, the flanges were covered with neat cement (put on dry or poured on in the form of thick grout) just before the concrete was placed. _invert concrete._--the form used for the landward type of concrete, that is, the one with a middle drain, consisted of a frame made of a pair of trussed steel rails on each side of the tunnel and connected at intervals with by -in. cross-timbers; two "wing forms" were hung from this frame by adjustable arms. these wings formed the curved sides of the invert, the lip, and the form for the middle drain. the whole form was supported on three wheels, two on the rear end running on a rail laid on the finished concrete, and the third in front attached to the frame by a carriage and running on a rail temporarily laid on the iron lining. the form was braced from the iron lining by by -in. blocks. for the soft-ground type of invert, namely, the one without the middle drain, a form of the same general type was used, except that the form for the middle drain was removed. after the form had been in use for some time, "key pieces" (made of strips of wood about ft. in. in length and by in. in cross-section) were nailed circumferentially on the under side of the wings at -ft. intervals. this was done because, at the time, it was not known whether ballasted tracks or some form of rigid concrete track construction would be adopted, and, if the latter, it was desirable not to have the surface smooth. the concrete was received in cars at the rear end of the form and dumped on a temporary platform. it was then loaded into wheel-barrows on the runways, as shown in fig. . the concrete was thrown from the barrows into the invert, where it was spaded and tamped. in cases where there was steel-rod reinforcement, the concrete was first brought up to the level of the underside of these rods, which came between the wings; the rods were laid in place, and then more concrete was placed over the rods and brought up to the level of the bottom of the wings. where there was no reinforcement, the concrete was brought up in one lift. [illustration: concrete form standard in river tunnels fig. .] after this was finished, the concrete behind the wings was placed, thoroughly spaded and tamped, and, where there were longitudinal reinforcing rods, these were put in at their proper level. where there were circumferential rods, the -ft. rods had already been put in when the lower part of the concrete was placed. as the invert was being finished off, the -ft. rods were embedded and tied in position. the longitudinal rods were held in place at the leading end of each length of arch by the wooden bulkhead, through which holes were drilled in the proper position. at the rear end they were tied to the rods projecting from the previous length. the quantity of water used in mixing the invert concrete needed very nice adjustment; if too wet, the middle would bulge and rise when the weight of the sides came on it; and, if too dry, it would not pack properly between the flanges of the iron lining. the difficulties as to this were often increased by the flow of accumulated leakage water from the tunnel behind on the concrete while it was being put in. to prevent this, a temporary dam of sand bags was always built across the last length of finished invert concrete before beginning a new length. a sump hole, about by ft. and ft. deep, was left every ft. along the tunnel, and a small cameron pump was put there to pump out the water. the invert forms were left in place about hours after the pour was finished. the average time taken to fill a length of feet was hours, the form was then left hours, and it took hours to set it up anew. the total time for one length, therefore, was hours, equal to ft. per hours. at one place, a -ft. form was used, and this gave an average speed of ft. per hours. an attempt was made to build the invert concrete without forms (seeing that a rough finish was desired, as previously explained, to form a key for possible sub-track concrete), but it proved a failure. the typical working force (excluding transport) was as follows: foreman @ $ . per shift. spaders " . " " laborers " . " " the average time taken to lay a -ft. length of invert was hours; the two spaders remained one hour extra, smoothing off the surface. for setting the form, the force was: foreman @ $ . per shift. carpenters " . " " carpenters' helpers " . " " the average time taken to erect a form was hours, carpenter and helper remaining until the concrete was finished. _duct bench concrete._--the duct bench (as described previously) is the portion of the concrete on which the ducts are laid. the exact height of the steps was found by trial, so as to bring the top of the ducts into the proper position with regard to the top and the face of the bench. both kinds of duct bench forms were of the same general type. a drawing of one of them is shown on plate xlii. the form consisted of a skeleton framework running on wheels on a track at the level of the temporary transportation tracks. the vertical faces of the steps were formed by boards supported from the uprights by adjustable arms. the horizontal surfaces were formed by leveling off the concrete with a shovel at the top of the vertical boards. where the sheets of expanded metal used for bonding came at a step, the lower edge of the boards forming the back of the step was placed in. above the one forming the front of it; but, when the expanded metal came in the middle of a step, a slot in. wide was left at that point to accommodate it. a platform was formed on the top of the framework for the form, and on this a car forming a sort of traveling stage was run. there was ample room to maintain traffic on a single track through the form. a photograph of the form is shown in fig. , plate xliii. the concrete, for the most part, was received at the form in ¾-cu. yd. dumping buckets. the buckets were lifted by the rope from a small hoisting engine. this rope passed over a pulley attached to the crown of the tunnel and dumped into the traveling stage on the top of the form. in this the concrete was moved along to the point where it was to be deposited, and there it was thrown out by shovels into the form below. for a portion of the period, while the duct bench concrete was being laid, it was not necessary to maintain a track for traffic through the form and, during that period, the concrete for the lower step was placed from below the form, the concrete being first dumped on a temporary stage at the lower track level. owing to the horizontal faces of the steps being uncovered, there was a tendency for the concrete there to rise when concrete was placed in the steps above. for this part of the work, also, it was necessary to see that the concrete was not mixed too wet, for, when that was the case, the concrete in the upper steps was very apt to flow out at the top of the lower one. at the same time, there was the standing objection to the mixture being too dry, namely, the responsibility of getting a sufficient amount of spading and tamping done. particulars of the exact quantity of water used are given later in describing "mixing." fig. , plate xliii, illustrates the process of laying. in the section of the tunnel in which there were circumferential reinforcement rods in the duct bench, the rods were in place before the laying commenced, as they had been placed with the invert concrete. the circumferential reinforcing rods in the arch came down into the upper part of the duct bench concrete; these rods were put in position and tied to the iron lining in the crown at the same time as the duct bench concrete was being finished off. openings for the manholes were left in the duct bench at the regular stationing. the average time taken to fill a length of ft. was about hours; the form was then left in position for about hours--usually enough to let the concrete set properly--and then moved ahead; it then took about hours to set it up again ready to continue work. the total time for a length, therefore, was about hours, equal to an average progress of about ft. per day. the average force engaged in duct bench concrete (not including transport) was: foreman @ $ . per day. spaders " . " " laborers " . " " _arch concrete._--by far the greater part of the arch work was put in with traveling centers before the face of the bench was built, in which case the whole of the arch was built at once. a short length of arch at each end of the tunnel was built after the face of the bench, in which case the haunches or lower ft. were laid first and the upper part of the arch later. the first traveling centers were used on the new york side, and were ft. long. the laggings were of -in. yellow pine, built up in panels ft. long and in. wide for the sides, and solely longitudinal lagging ft. long for the key. it was pretty certain that the results to be obtained from forms of such a length would not be satisfactory, and this was pointed out to the contractor, who, however, obtained permission to use them on trial. grout pipes were built in, as it was not likely that the concrete could be packed tightly into the upper part of the lining. [illustration: plate xliii. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. .] [illustration: plate xliii. trans. am. soc. civ. engrs. vol. lxviii, no. . hewett and brown on pennsylvania r. r. tunnels: north river tunnels. fig. .] after about lin. ft. of arch had been built with these forms, a test hole was cut out and large voids were found, and, to confirm this, another hole was cut, and similar conditions observed. the results were so unsatisfactory that orders were given that the use of longitudinal key lagging should be discontinued, and cross or block lagging used instead. these block laggings were in. in length (in the direction of the tunnel) and ft. in width; at the same time, the system of grout pipes was changed. this will be described later under "grouting." it was soon found that with block lagging a better job could be made of packing the concrete up into the keys, but the time taken to "key up" a -ft. length was so great that the rest of the arch had set by the time the key was finished. despite a lot of practice, this was the case, even in the unreinforced type. when the reinforcing rods were met, the time for keying up became still greater, and therefore the contractor was directed to shorten the forms to -ft. lengths. a typical working force for a -ft. length was: foreman @ $ . per day. spaders " . " " laborers " . " " details of the -ft. forms are shown on plate xliv. the lower ft. of lagging was built on swinging arms, which could be loosened to allow the centers to be dropped and moved ahead. the rest of the lagging was built up in panels ft. long and ft. in. high. the ribs rested on a longitudinal timber on each side; these were blocked up from the top step of the duct bench concrete. when the form was set, or when it was released, it was moved ahead on rollers placed under it. the concrete was received at the form in ¾-cu. yd. dumping buckets; from the flat cars on which they were run, these were hoisted to the level of the lower platform of the arch form. at this level the concrete was dumped on a traveling car or stage, and moved in that to the point on the form where it was to be placed. for the lower part of the arch, the concrete was thrown directly into the form from this traveling stage, but, for the upper part, it was first thrown on the upper platform of the arch. the hoisting was done by a small lidgerwood compressed-air hoister, and set up on an overhead platform across the tunnel. the pulley over which the cable from the hoister passed was attached to the iron lining near one end of the form, and the traveling stage ran back from the arch form on a trailer, shown on plate xliv. when it was impossible to hang a pulley--owing to the concrete arch having been built at the point where the trailer stood--an =a=-frame was built on the trailer, and the pulley was attached to that. in laying the lower part of the arch, about ft. of lagging (including the swinging arms) was first set, the other panels being pulled up toward the top of the arch. when that was filled, the next panel above was lowered into place, and the work continued. as the concrete rose toward the key, it was packed up to a radial surface, so that the arch would not be unduly weakened if the sides set before the key was placed. all the time, great care was taken to see that the concrete was carefully packed into the segments of the metal lining. the quantity of water used in the concrete was carefully regulated, more being used in the lower than in the upper parts of the arch. in places where there were no reinforcing rods, the width of the concrete key was the length of the block lagging, namely, ft. where there was circumferential reinforcement, the key had to be more than ft. wide, in order to take the -ft. closure rods used in the key. this naturally increased the time of keying very much. on the places where the -ft. longitudinal laggings were used, it was impossible to fill the flanges of the metal lining much higher than their undersides. as the concrete used in the key had to be much drier than that used elsewhere, it was not easy to get a good surface. this trouble was overcome by putting a thin layer of mortar on the laggings just before the concrete was put in. the overhead conductor pockets were a great hindrance to the placing of the key concrete, especially where the iron was below true grade. whenever an especially troublesome one was met, a special grout pipe was put in to fill up unavoidable holes by grouting after the concrete had set. all the circumferential reinforcing rods were bent in the tunnel by bending them around a curved form of less diameter than the required bend. this generally left them all right in the middle of their length, but with their end portions too straight; in such cases the ends were bent again. all rods were compared with a template before being passed for use. the arch forms were left up for hours after keying was finished. levels taken after striking the forms showed that no appreciable settlement occurred. an average gang for a -ft. length of arch was: foreman @ $ . per shift. spaders " . " " laborers " . " " table shows the progress attained under various conditions. whenever the face of the bench concrete was constructed before the arch, the latter was built in two separate portions, that is, the bottom ft., or "haunches" of the arch, as they were termed, were built on each side and the rest of the arch later. this involved the use of two separate sets of forms, namely, for the haunch and for the arch. not very much arch was built in this way, and, as the methods were in principle precisely the same as those used when all the arch was built in one operation, no detailed description is needed. no provision was made in the contract for grouting the concrete arch, but it soon became evident that by ordinary methods the top part of the concrete could not be packed solid against the iron segments, especially in the keys. as it was imperative to have the arch perfectly solid, it was determined to fill these unavoidable gaps with a : portland cement grout, at the same time making every effort to reduce the spaces to a minimum. this made it necessary to build grout pipes into the concrete as it was put in. the first type of grout pipe arrangement is shown as type _a_, in fig. . this was used with the longitudinal key laggings; when this method was found to be no good, and cross-laggings were used, the system shown as type _b_, in fig. , was adopted, in which vents were provided to let out the air during grouting. the expense of these pipes was high, and the contractor obtained permission to use sheet-iron tubes, which, however, were found to be unsuitable, so that the screwed pipes were used again. the contractor next obtained permission to try dispensing altogether with the vent pipes, and so type _c_, in fig. was evolved. this, of course, was found to be worse than any of the other systems, as the imprisoned air made it impossible to force grout in. several other modifications were made, and are shown in fig. . it was then decided to devise as perfect a system as possible, without allowing the question of cost to be the ruling factor, and to use that system throughout. in this system, shown as type _s_, in fig. , most of the vent pipes were contained in the concrete, and their size was independent of the thickness of the arch, so that they were easily fixed in position and not subject to disturbance while placing the concrete. this system was used for about % of the total length of the tunnel, and proved entirely satisfactory. the machine used for grouting was the same as that used for grouting outside the metal lining. table .--average time taken for various operations connected with building concrete arches in subaqueous tunnels. ==========+=============+========+================+=========+=========+ average |type of |length |time, in hours, |time, |time, | time |reinforcement|of |moving and |in hours,|in hours,| in hours, | |section,|erecting forms. |placing |placing | form stood| |in | |concrete |concrete | after | |feet. | |in arch. |in key. | filing. | | | | | | | | | | | | ----------+-------------+--------+----------------+---------+---------+ | { a | } | | | . | | {day work | } | ______/\______ | | | | | |/ \| | | | { a | } |moving erecting| | | | {day work | } | | . | . | | | | | | | | { b | } | | | | | {day work | } | | . | . | | | | | | | | { c | } | | | | | {day work | } | | . | . | | | | | | | | { d | } | | | | | {day work | } | | . | . | | | | | | | | { d | } | | | | | {day work | } | | . | . | | | | | | | | {sub-type | } | | . | . | | no. | } | | | | | piece work | } | | | | ==========+=============+========+================+=========+=========+ ==========+=========+===========+===========+============ average |time, |total time |total time |remarks. time |in hours,|in hours, |in hours, | in hours, |placing |for moving,|per linear | form stood|concrete |erecting, |foot, | after |in key |and filling|for moving,| filing. |and arch | |erecting, | | | |and filling| ----------+---------+-----------+-----------+------------ | . | . | . | | | | | | | | | | | | | | . | . | . | | | | | | | | |includes | . | . | . |placing rods | | | | | | | | | . | . | . | do. | | | | | | | | | . | . | . | do. | | | | | | | | | . | . | . | do. | | | | | . | . | . | do. | | | | | | | | ==========+=========+===========+===========+============ [illustration: fig. .] the only compressed air available was the high-pressure supply, at about lb.; a reducing valve, to lower this pressure to lb. was used between the air line and the grouting machine. this was thought to be about as high a pressure as the green concrete arch would stand, and, even as it was, at one point a section about ft. by ft. was blown out. a rough traveling stage resting on the bottom step of the duct bench concrete was used as a working platform. in the earlier stages of the work the grouting was carried on in a rather haphazard manner, but, when the last system of grout and vent pipes was adopted; the work was undertaken systematically, and was carried out as follows: two -ft. lengths of arch were grouted at one time, and, in order to prevent the grout from flowing along the arch and blocking the pipes in the next lengths, a bulkhead of plaster was made at the end of every second length to confine the grout. after a section had been grouted, test holes were drilled every ft. along the crown to see that all the voids were filled; if not, holes were drilled in the arch, both for grouting and for vents, and the faulty section was re-grouted. an average of ¾ bbl. of cement and an equal quantity of sand was used per linear foot of tunnel. the average amount put in by one machine per shift was bbl., and therefore the average length of tunnel grouted per machine per shift was ft. the typical working force was: foreman @ $ . per shift laborer running grout machine " . " " laborers handling cement and sand. " . " " laborer tending valve and grout pipes " . " " after the grouting was finished, the arches were rubbed over with wire brushes to take off discoloration, and rough places at the junctions of adjoining lengths or left by the block laggings were bush-hammered. _face of bench concrete._--the form used for this portion of the work is shown on plate xlv. it consisted of a central framework traveling on wheels, and, from the framework, two vertical forms were suspended, one on each side, and equal in height to the whole height of the bench. adjusting screws were fitted at intervals both at top and bottom, and thus the position of the face forms could be adjusted accurately. the face forms were built very carefully of -in. tongued and grooved yellow pine, and one -ft. form was used for , ft. of tunnel without having the face renewed. great care was taken to set these forms true to line and grade, as the appearance of the tunnel would have been ruined by any irregularity. joints between successive lengths were finished with a =v=-groove. the concrete was received at the form in dumping buckets; these were hoisted to the top of the form by a lidgerwood hoister fixed to a trailer. the concrete was placed in the form by shoveling it from the traveling stage down chutes fitted to its side. the quantity of water to be used in the mixture needed careful regulation. the first few batches in the bottom had to be very wet, and were made with less stone than the upper portion, in order that the concrete would pack solidly around the niche box forms and other awkward corners. the forms for the ladders and refuge niches were fastened to the face of the bench forms by bolts which could be loosened before the main form was moved ahead, and in this way the ladder and niche forms were left in position for some time after the main form was removed. at first the forms were kept in place for hours after finishing a length, but, after a little experience, hours was found to be enough. in the summer, when the rise of temperature quickened the set, the time was brought down to hours. the average time taken for a -ft. length was: laying concrete ½ hours. interval for setting " moving forms ahead and resetting " ------- total ½ hours. the typical working gang was: _laying concrete._ foreman @ $ . per shift. spaders " . " " laborers " . " " _moving and setting forms._ foreman @ $ . per shift. laborers " . " " after the forms were removed, any rough places at the lower edge, where the concrete joins the "lip," were bush-hammered; no other cleaning work was done. _duct laying and rodding._--the design and location of the ducts have already been described. it will have been seen that the duct-bench concrete was laid in steps, on which the ducts were laid, hence the maintenance of the grade and line in the ducts was an easy matter. the only complication was the expanded metal bonds, which were bent up out of the way of the arch forms and straightened out again after the arch forms had passed. the materials, such as ducts, sand, and cement, were brought into the tunnel by the regular transportation gang. the mortar was mixed in a wooden trough about ft. long, ft. in. wide and in. deep. after the single-way ducts had been laid, all the joints were plastered with mortar, in order to prevent any foreign substance from entering the ducts. this was not necessary with the multiple duct, as the joints were wrapped with cotton duck. the ducts were laid on a laying mandrel, and, as soon as possible after the concrete was laid around a set of ducts, they were "rodded" with a rodding mandrel. not many obstructions were met, and these were usually some stray laying mandrel which had been left in by mistake, or collections of mortar where the plastering of the single-way joints had been defective. in the , duct ft. of conduit in the river tunnels only eight serious obstructions were met. that the work was of exceptionally high quality is shown by the fact that a heavy -in. lead cable has been passed through from manhole to manhole ( ft.) in min., and the company, engaged to lay the cables in these ducts, broke all its previous records for laying, not only for tunnel work, but also in the open. fig. , plate xxxv, shows a collection of the tools and arrangements used in laying and rodding ducts. the typical working force was: _laying multiple ducts._ foreman @ $ . per shift. laborers " . " " _laying single-way ducts._ foreman @ $ . per shift. laborers " . " " _rodding multiple ducts._ foreman @ $ . per shift. laborers " . " " _rodding single-way ducts._ foreman @ $ . per shift. laborers " . " " the average progress per -hour shift with such gangs was: laying multiple ducts , duct ft. laying single-way ducts , " " rodding multiple ducts , " " rodding single-way ducts , " " no detailed description need be given of the concreting of the cross-passages, pump chambers, sumps, and other small details, the design of which has been previously shown. the concrete was finished on june st, . _period no. ._--_final cleaning up._--_june, , to november, ._--as soon as all the concrete was finished, the work of cleaning up the invert was begun. a large quantity of débris littered the tunnels, and it was economical to remove it as quickly as possible. the remaining forms were first removed, and hoisting engines, supported on cross-timber laid across the benches, were set up in the middle of the tunnel at about -ft. intervals. work was carried on day and night, and about ft. of single tunnel was cleared per -hour shift. work was begun on may th, and finished on july th, . for part of the time it was carried on at two points in each tunnel, working toward the two shafts, but when the work in the weehawken shaft, which was being done at the same time, blocked egress from that point, all material was sent out by the manhattan shaft. the total quantity of material removed was , cu. yd., or about . cu. yd. per lin. ft. of tunnel. the average force per shift was: _in tunnel._ foremen @ $ . per shift hoist engineer " . " " signalman " . " " laborers " . " " _on the surface._ foreman @ $ . per shift hoist engineer " . " " signalman " . " " laborers " . " " after the cleaning out had been done, the contractor's main work was finished. however, quite a considerable force was employed, up to november, , in doing various incidental jobs, such as the installation of permanent ventilation conduits and nozzles at the intercepting arch near the manhattan shaft, the erection of a head-house over the manhattan shaft, and collecting and putting in order all the miscellaneous portable plant, which was either sold or returned to store, sorting all waste materials, such as lumber, piping, and scraps of all kinds, and, in general, restoring the sites of the working yards to their original condition. concrete mixing. the plant used in mixing the concrete for the land tunnels was pulled down and re-erected before the concrete work in the river tunnels was begun. at the new york shaft two new bins for sand and stone were built, bringing the total capacity up to cu. yd. two no. ransome mixers, driven electrically by -h.p. general electric motors, using current from the contractor's generators, were set up on a special platform in the intercepting arch. at manhattan the sand and stone were received from the bins in chutes at a small hopper built on the permanent upper platform of the intercepting arch. bottom-dumping cars, divided by a partition into two portions, arranged to hold the proper quantities of sand and stone for a -bag batch of concrete, were run on a track on this upper platform, filled with the proper quantities of sand and stone, and then run back and dumped into the hoppers of the mixer. after mixing, the batch was run down chutes into the tunnel cars standing on the track below. the water was brought in pipes from the public supply. it was measured in barrels by a graduated scale within the barrels. the water was not put into the mixer until the sand and stone had all run out of the mixer hopper. the mixture was revolved for about ½ min., or about complete revolutions. at weehawken shaft the mixing plant was entirely rebuilt. four large bins, two for sand and two for stone, were built in the shaft. together, they held cu. yd. of stone and cu. yd. of sand. the sand and stone were dumped directly into the bins from the cars on the trestle which ran from the wharf to the shaft. the materials were run through chutes directly from the bins to the hoppers of the mixers, where they were measured. two no. ransome mixers, electrically driven, were used here, as at new york, and, as there, the water was led into measuring tanks before being let into the mixer. the quantity of water used in the various parts of the concrete cross-section, for a -bag batch consisting of bbl. ( lb.) of cement, . cu. ft. of sand, and . cu. ft. of stone, is given in table . table .--quantity of water per -bag batch of concrete, in u.s. gallons. ==========================+==========+==========+========== portion of cross-section. | maximum. | minimum. | average. --------------------------+----------+----------+---------- invert | | | duct bench | | | arch (excluding key) | | | key of arch | | | face of bench | | | ==========================+==========+==========+========== the maximum quantities were used when the stone was dry and contained more than the usual proportion of fine material, the minimum quantity when the sand was wet after rain. the resulting volumes of one batch, for various kinds of stone, are given in table . table .--volume of concrete per batch, with various kinds of stone. ========+===========+================+===========+==================| | | resulting | | | description of stone. |volume per | | mixture.|-----------+----------------| barrel of | remarks. | | | |cement, in | | | passed | retained on | cubic | | | screen. | screen. | yards. | | --------+-----------+----------------+-----------+------------------| : ½: | ½-in. | / -in. | . | measured in air | : ½: | ½-in. |run of crusher. | . | " " " | : ½: | -- |general average.| . [d]|measured from plan| : ½: | -in. | ½-in. | . [e]| " " " | ========+===========+================+===========+==================| [d] average for whole of river tunnel section. [e] average from , cu. yd. in land tunnel section. the sand used was practically the same for the whole of the river tunnel section, and was supposed to be equal to "cow bay" sand. the result of the mechanical analysis of the sand is shown on plate xlvi. the stone was all trap rock. for the early part of the work it consisted of stone which would pass a -in. ring and be retained on a ½-in. ring, in fact, the same as used for the land tunnels. this was found to be too coarse, and for a time it was mixed with an equal quantity of fine gravel or fine crushed stone. as soon as it could be arranged, run-of-crusher stone was used, everything larger than ½ in. being excluded. about three-quarters of the river tunnel concrete was put in with run-of-crusher stone. the force was: _at manhattan._ foreman @ $ . per shift men on sand and stone cars " . " " men handling cement " . " " men dumping mixers " . " " _at weehawken._ foreman @ $ . per shift men hauling cement " . " " men dumping mixers " . " " the average quantity of concrete mixed per -hour shift was about batches, or about cu. yd. the maximum output of one of the mixers was about batches, or cu. yd. per -hour shift. transportation. _surface transportation._--at manhattan the stone and sand were received in scows at the wharf on the river front. for the first part of the work, the wharf at d street and north river was used, and while that was in use the material was unloaded from the scows into scale-boxes by a grab-bucket running on an overhead cable, and then teamed to the shaft. for the latter part of the work, the wharf used was at th street and north river, where facilities for unloading were given to the contractor by the pennsylvania railroad company which was the permanent lessee of the piers. the material was unloaded into scale-boxes by a grab-bucket operated by a derrick, and teamed to the shaft. when the scale-boxes arrived at the shaft they were lifted from the trucks by derricks and dumped into the bins. at weehawken all the stone and sand, with the exception of the stone crushed on the work, was received by water at the north slip. here it was unloaded by a -cu. yd. grab-bucket and dumped into -cu. yd. side-tipping cars, which were hauled by a small steam locomotive over the trestle to the shaft, where they were dumped directly into the bins. before beginning the concrete lining, the -ft. gauge railway, which had been used for the surface transportation during the driving of the iron-lined tunnels, was taken up and replaced by a -ft. gauge track consisting largely of -lb. rails. the cars were -cu. yd. side-dumping, with automatic swinging sides. two steam locomotives which were being stored at weehawken (part of the plant from another contract), were used for hauling the cars in place of the electric ones used with the -ft. gauge railway. _tunnel transport._--the track used in the tunnel was of -ft. gauge, laid with the -lb. rails previously used in driving the iron-lined tunnels. the mining cars (previously mentioned in describing the driving of the iron-lined tunnels) were used for transporting the invert concrete, although, for most of the work, dumping buckets carried on flat cars were used. several haulage systems were considered for this work, but not one of them was thought to be flexible enough to be used with the constantly changing conditions, and it was eventually decided to move all the cars by hand, because, practically all the work being down grade, the full cars could be run down by gravity and the empty ones pushed back by hand. two men were allotted to each car, and were able to keep the traffic moving in a manner that would have been perhaps impossible with any system of mechanical haulage. this system was apparently justified by the results, for the whole cost of the tunnel transport, over an average haul of about , ft., was only about cents per cu. yd., which will be found to compare favorably with mechanical haulage on similar work elsewhere, provided full allowance is made for the use of the plant and power. _force employed._--the average force employed on transport, both on the surface and in the tunnel, is shown in table . costs. during the work, careful records of the actual cost to the contractor of carrying out this work were kept by the company's forces; these costs include all direct charges, such as labor and materials, and all indirect charges such as head office, plant depreciation, insurance, etc., but do not include the cost of any financing, of which the company had no information. table .--average force per shift for transportation in two tunnels. ========+==================+=====+==========+============+===========+ location|grade |rate | work in progress | | | |----------+------------+-----------+ | | | two |two arches, |four arches| | | | inverts |two inverts,| and one | | | | and two |and two duct| face of | | | | duct | benches | bench | | | | benches | | | --------+------------------+-----+----------+------------+-----------+ {|foreman |$ . | | | | tunnel {|laborer | . | | | | {|switchmen | . | | | | {|hoisting engineers| . | | | | {|foreman | . | | | | surface{|laborers | . | | | | {|teams | . | | | | ========+==================+=====+==========+============+===========+ field engineering staff. the field staff may be considered as divisible into five main divisions: (_a_).--construction, including alignment, (_b_).--cost records, (_c_).--testing of cement and other materials of construction, (_d_).--photography, (_e_).--despatch-boat service. (_a_).--_construction_ (_inspection and alignment_) _staff._--a comparatively large staff was maintained by the company, and to this two causes contributed. in the first place, the contractor maintained no field engineering staff, because, early in the proceedings, it was arranged that the company would carry out all this work, and thus avoid the overlapping, confusion, and lack of definite responsibility which often ensues when two engineering forces are working over the same ground. even had the contractor maintained an engineering force, it would have been necessary for the company to check most of the contractor's work. in the second place, this work gave rise to a number of special surveys, tests, borings, and observations of various kinds, most of which were kept up as a part of the regular routine work, and this necessitated a staff. also, for a whole year, active progressive work was at a standstill while the pile tests were going on. (_b_).--_cost records staff._--a distinct feature was made of keeping as accurately as possible detailed records of the actual cost to the contractor of carrying out the work. a small staff of clerks, retained solely for this purpose, tabulated and recorded the information furnished by the members of the construction staff. about $ , , altogether, was spent in salaries in this department, and it may be considered an extremely wise investment, for, not only is the information thus obtained of great value and interest in itself, but it also puts the company in an excellent position should any claim or discussion arise with the contractor. (_c_).--_cement-testing department._--as the company furnished the cement to the contractor, it became incumbent to make careful tests of the quality. a cement-testing laboratory was established at the manhattan shaft offices, under the charge of a cement inspector who was furnished with assistants for sampling, shipping, and testing cement. all materials used on the work, such as bricks, sand, stone, water-proofing, etc., were tested here, with the exception of metals, which were under the charge of a metal inspector reporting directly to the head office. this department cost about $ , for salaries and $ , for apparatus and supplies, or about $ , , in all. there were , bbl. of cement tested, and samples from , , brick. a large amount of useful information has resulted from the work of this laboratory. (_d_).--_photography._--it was desired to keep a complete photographic record of the progress of the work, and therefore a photographer was appointed, with office room at the manhattan shaft. the photographer took all the progress photographs on the work of the north river division, made photographic reductions of all drawings and plans, made lantern slides of all negatives of a more important nature, and, in addition, during the period of compressed air, analyzed the samples of compressed air, brought into the office for the purpose, for the amount of co_{ } present. about $ , was spent on this department. (_e_).--_despatch-boat service._--to provide access to the new jersey side, a despatch boat was purchased. this boat was at first (june, ) chartered, and in may, , was bought outright, and ran on regular schedules, day and night. it continued in the service until april, , when it was given up, as the tunnels were so far completed that they provided easy access to new jersey. the cost of the boat (second-hand) was about $ , . it was then thoroughly overhauled and the cabin remodeled. the monthly cost, when working a -hour shift, was $ for manning, $ for supplies, and $ for coal. on two -hour shifts, the monthly cost was $ for manning, $ for supplies, and $ for coal. about , passengers were carried during the boat's period of service, and the total cost was about $ , . for the major part of the period embraced by this paper, b. h. m. hewett, m. am. soc. c. e., served as general resident engineer, in charge of the field work as a whole. w. l. brown, m. am. soc. c. e., was at first resident engineer of the work constructed from the manhattan shaft, while h. f. d. burke, m. am. soc. c. e., was resident engineer of the work constructed from the weehawken shaft. after the meeting of the shields, mr. burke left to take up another appointment, and from that time mr. brown acted as resident engineer. it may be said, without reflecting in any way on the manufacturers, that the high standard of all the metal materials also testified to the efficient inspection conducted under the direction of mr. j. c. naegeley. it is impossible to close this brief account of these tunnels without recording the invaluable services at all times rendered by the members of the company's field staff. where all worked with one common aim it might seem invidious to single out names, but special credit is due to the following assistant engineers: messrs. h. e. boardman, assoc. m. am. soc. c. e., w. h. lyon, h. u. hitchcock, e. r. peckens, h. j. wild, assoc. m. am. soc. c. e., j. f. sullivan, assoc. m. am. soc. c. e., and r. t. robinson, assoc. m. am. soc. c. e. mr. c. e. price was in charge of the cement tests throughout the entire period, and brought to his work not only ability but enthusiasm. mr. h. d. bastow was in charge of the photographic work, and mr. a. l. heyer of the cost account records, in which he was ably seconded by mr. a. p. gehling, who, after mr. heyer's departure, finished the records and brought them into their final shape. the organization of the company's field engineering staff is shown graphically by fig. . field organization of the o'rourke engineering construction company for the building of the pennsylvania railroad tunnels into new york city--north river division. sections gy east, gy west supplementary, gy west, and co. general superintendent. | +------------------------+-------+--+ | | | (general, surface and office) (excavation | ---------------+------------- of land | | tunnels) | assistant general superintendent | | | general | | rock supt | +------------+------------+ | | | | | tunnel | field surface despatch supts | office boat tunnel | foreman | civil head captain foremen | engineer carpenter engineer timbermen | inspectors foreman deck hands timbermen | bookkeepers carpenter timbermen's | paymaster carpenters helpers | head carpenters' foremen | storekeeper helpers drillers | storekeepers blacksmiths drillers | timekeepers blacksmiths' foremen | telephone helpers muckers | operators foreman pipe fitters | office boys laborers pipe fitters' | messengers laborers helpers | janitors disposal electricians | trimmers hoist | teamsters engineers | signalmen | muckers | nippers | water boys | | | -------------+--------+-------------------------+--------+----------+ | | | | (shield tunnel driving) (masonry (power (medical | lining-rock plant) supervision) general tunnel superintendent and river | | | tunnels) master chief med assistant superintendents | mechanic officer | | | | | | | +--------+------------+---------+ | foreman | excavation | | general | electrician | | iron lining caulking and | | electricians | general | grummeting | | engineers | foremen foremen | pipefitters | foreman resident foremen erector foremen pipefitters' | machinist doctor drillers runners caulkers helpers | machinists drillers ironmen grummeters electricians | machinists' powdermen boltmen electricians'| helpers foremen helpers | firemen timbermen trackmen | oilers timbermen lockmen | pumpmen foremen transport | hoist engineers muckers foreman | signalmen muckers transport | shieldmen laborers | laborers watchmen | nippers | water boys | general concrete superintendent | tunnel superintendents | +-----------+------------+----------------++-----------+ | | | | | concrete brickwork ducts water-proofing general foremen foremen foremen foremen pipefitters carpenters bricklayers duct-layers waterproofers pipefitters' carpenters' bricklayers' helpers helpers laborers electricians mixer carpenters electricians' foremen carpenters' helpers mixer helpers transport laborers foremen concrete transport laborers laborers watchmen fig. . _contractor's organization._--the contracting firm which did the work described in this paper was the o'rourke engineering construction company, of new york city. the president of this company was john f. o'rourke, m. am. soc. c. e., the vice-president was f. j. gubelman, assoc. m. am. soc. c. e. the general superintendent was mr. george b. fry, assisted by j. f. sullivan, assoc. m. am. soc. c. e. the duties of general tunnel superintendent fell to mr. patrick fitzgerald. the generally pleasant relations existing between the company and the contractor's forces did much to facilitate its execution. the organization of the contractor's field staff is shown on fig. . pennsylvania tunnel and terminal railroad company. north river division. sections gy east, gy west supplementary, gy west, gj, and i, _i. e._, from th avenue, manhattan, to the weehawken shaft, field engineering staff organization. general resident engineer | +-----------------+------------+------------+---------+----+ | | | | | | (material testing) (photography) | (cost records) |(office) cement inspector photographer | recording clerk | clerks asst cement | asst recording |messengers inspectors | clerks | (construction) | | (despatch boat) +----------------+ captain | engineers resident engineers deckhands (two during driving of shield-driven messengers tunnels, and one subsequently.) | +---------------------+---+------------------+ | | | (inspection) (alignment) (office) assistant engineers assistant engineers draftsmen chief tunnel chiefs of parties field office inspector instrumentmen clerks tunnel inspectors rodmen cement surface inspectors chainmen warehousemen clerks laborers janitors fig. in conclusion, the writers cannot forego the pleasure of expressing their deep obligation to samuel rea, m. am. soc. c. e., as representing the management of the company, to the chief engineer, charles m. jacobs, m. am. soc. c. e., and to james forgie, m. am. soc. c. e., chief assistant engineer, for their permission to write this paper, and also to all the members of the field office staff for their great and unfailing assistance in its preparation. [transcriber's note: bolded sections are rendered with equal signs e.g. =bold=. the oe ligature is rendered as[oe] e.g. ph[oe]nixville. the following table is a cross index relating asce papers to project gutenberg(tm) file directories e.g. http://www.gutenberg.org/files/ / for paper . +-----+------------------------------------------------------+------+ |paper|paper name & author | pg | | no | | file | | | | no | |-----+------------------------------------------------------+------| | |the new york tunnel extension of the pennsylvania | | | |railroad. by charles w. raymond | | | |the north river division. by charles m. jacobs | | | |the east river division. by alfred noble | | | |meadows division and harrison transfer yard. by e. b. | | | |temple | | | |the bergen hill tunnels. by f. lavis | | | |the north river tunnels. by b. h. m. hewett and w. l. | | | |brown | | | |the terminal station west. by b. f. cresson, jr. | | | |the site of the terminal station. by george c. clarke | | | |the cross town tunnels. by james h. brace and francis | | | |mason | | | |the east river tunnels. by james h. brace, francis | | | |mason, and s. h. woodard | | +-----+------------------------------------------------------+------+ ] transactions of the american society of civil engineers (instituted ) vol. lxviii september, edited by the secretary, under the direction of the committee on publications. reprints from this publication, which is copyrighted, may be made on condition that the full title of paper, name of author, and page reference are given. new york published by the society * * * * * entered according to act of congress, in the year , by the american society of civil engineers, in the office of the librarian of congress, at washington. * * * * * note.--this society is not responsible, as a body, for the facts and opinions advanced in any of its publications. contents the new york tunnel extension of the pennsylvania railroad no. page the new york tunnel extension of the pennsylvania railroad. by charles w. raymond the north river division. by charles m. jacobs the east river division. by alfred noble meadows division and harrison transfer yard. by e. b. temple the bergen hill tunnels. by f. lavis the north river tunnels. by b. h. m. hewett and w. l. brown the terminal station-west. by b. f. cresson, jr. the site of the terminal station. by george c. clarke the cross-town tunnels. by james h. brace and francis mason the east river tunnels. by james h. brace, francis mason, and s. h. woodard memoirs of deceased members page john fiske barnard, m. am. soc. c. e. robert l. engle, m. am. soc. c. e. charles herbert deans, assoc. m. am. soc. c. e. william meier, assoc. m. am. soc. c. e. =this volume and the succeeding volume of transactions (vol. lxix) will contain all the papers descriptive of the new york extension of the pennsylvania railroad. a general index covering both volumes will be issued in vol. lxix.= plates plate paper page i. map and profile, pennsylvania tunnel & terminal r. r., north bergen tunnel to long island city ii. map and profile, harrison yard to bergen hill tunnel iii. plan of sunnyside yard iv. view of tunnel under part of atlantic avenue, brooklyn, n.y. v. new york underground railway company: section through surface and underground stations vi. pennsylvania railroad extension: map showing proposed lines leading to those finally adopted vii. plan, profile, and triangulation, north river tunnels viii. typical sections between manholes, bergen hill tunnels ix. map of manhattan island from twenty-third to fortieth streets x. manhattan shaft, lines a and b xi. long island shaft, lines a and b xii. typical tunnel sections xiii. plan and profile, east river tunnels xiv. map and profile, cross-town tunnels xv. plan and profile of lines a and b, and sunnyside yard xvi. plan and profile of the pennsylvania tunnel & terminal r. r., from harrison, n. j., to the hudson river xvii. plan of harrison yard xviii. details of shelters and platforms, harrison transfer station xix. details of shelters and platforms, harrison transfer station xx. lift rail and locking device for hackensack river draw-bridge xxi. hackensack portal, bergen hill tunnels; method of using cross-section rod; and belt conveyor for handling and placing concrete xxii. scaffold car; headhouse; and round holes in concrete forms xxiii. record of drilling, air pressure, mucking, etc., in bergen hill tunnels xxiv. belt conveyor for handling and placing concrete; water-proofing, portion of completed sand-wall, etc.; and methods of placing concrete in forms and bench-walls xxv. telephone and telegraph ducts and mandrels; tunnel lining forms; placing water-proofing; and section of completed lining xxvi. form of circuit-breaker chamber and traveling gantry; forms for storage chamber; rock packing over arches; method of water-proofing in timbered tunnels, etc. xxvii. method of placing water-proofing and keying arch; view of completed tunnel; general view of completed hackensack tunnel and arches through cut-and-cover section; and view of hackensack approach xxviii. plan and profile of parts of north river tunnels xxix. weehawken shaft; and tunnel shield showing hood xxx. yard and offices at manhattan and weehawken shafts xxxi. tunneling shield xxxii. thirty-second street tunnels and shield chambers xxxiii. general methods of excavation adopted for land tunnels xxxiv. plan and longitudinal section of weehawken tunnels xxxv. apparatus for cleaning and rodding electric cable ducts xxxvi. diagram showing lines and grades in river tunnel north xxxvii. cross-section of subaqueous tunnels showing reinforcement xxxviii. back of shield in south tunnel; and rear view of shield during erection of first ring of iron lining plate paper page xxxix. view of meeting of shields; and lowering segment into tunnel invert xl. sections of tunnel during construction, showing shield, air locks, platforms, etc. xli. placing key segment; and method of grouting outside iron xlii. duct bench concrete form in river tunnels xliii. end of portable and adjustable forms for building side bench; and steel rod reinforcement in river tunnels xliv. details of -ft. movable form and traveler for concrete arches xlv. traveling concrete form for face of bench walls xlvi. mechanical analysis of sand used in mortar and concrete xlvii. views showing condition of work at site of terminal station xlviii. views showing excavation and supports for ninth avenue structures xlix. views showing underpinning for ninth avenue elevated railway l. views showing condition of work between ninth and tenth avenues, and progress on concrete walls li. views showing box drains and tie-rods in walls; the completed tenth avenue portal; and the disposal trestle lii. girders under the ninth avenue elevated railroad; method of supporting elevated railway columns; and view of inside of form for walls, showing drains, tie-rods, etc. liii. pennsylvania station, new york city; plan showing area at track level liv. diagram showing widths of base of retaining wall required for different batters and pressures, pennsylvania station lv. material trestle over n. y. c. & h. r. r. r. co.'s tracks; and construction of pier no. , north river lvi. material trestle showing first chutes in operation; and views of east and west pits at terminal site lvii. methods of excavation, cross-town tunnels, manhattan lviii. views of parts of first avenue plant, cross-town tunnels lix. methods of tunneling, timbering, and lining, cross-town tunnels lx. methods of timbering and underpinning, cross-town tunnels lxi. sections showing method of excavating and timbering in heavy ground, three-track tunnel; and carriage form for side walls, cross-town twin tunnels lxii. methods of water-proofing and concreting, cross-town tunnels lxiii. methods of excavation in all rock, east river tunnels lxiv. tunneling in compressed air, air-lock, caisson, etc., east river tunnels lxv. shields fitted with sectional sliding hoods and sliding extensions and with fixed hoods and fixed extensions to floors, east river tunnels lxvi. rear of shield showing complete fittings, and shield with lower portion of bulkhead removed, east river tunnels lxvii. methods of tunneling in rock, east river tunnels lxviii. operation of shields, east river tunnels lxix. operations in shoving the shield forward in rock and sand, east river tunnels lxx. small shaft, breasting and poling, shutters on front of shield, and hydraulic erector, east river tunnels lxxi. operations in shoving the shield forward in sand, and final breasting and bulkheading, east river tunnels lxxii. method of operating shields in soft ground, east river tunnels lxxiii. reinforcement of broken plates, and inflow of soft clay through shield, east river tunnels lxxiv. methods of placing concrete inside the iron tube, east river tunnels memoirs of deceased members. =john fiske barnard, m. am. soc. c. e.=[ ] [ ] memoir prepared by w. k. barnard, assoc. m. am. soc. c. e. died february th, . john fiske barnard was born in worcester, mass., on april d. . he was graduated from the bridgewater normal school, and from rensselaer polytechnic institute. in november, , mr. barnard entered the railway service. he held various engineering and operating positions with the grand trunk railway and its subsidiary lines in lower canada, and served as chief engineer of the grand trunk south of the st. lawrence river for the last three years of his connection with that road. in may, , he went to the missouri valley railroad as superintendent and chief engineer. during the same year he was appointed chief engineer of the kansas city-st. joseph and council bluffs railroad, and remained with this road and the hannibal and st. joseph railroad (both now a part of the burlington missouri lines), as chief engineer, general superintendent, and general manager, until . during this time mr. barnard was also president of the atchison union depot company and the st. joseph union stock yards company, secretary and treasurer of the st. joseph depot company, and director in various railroad companies. in , mr. barnard was appointed president and general manager of the ohio and mississippi railway, which position he occupied until . from that time until , he was engaged on several reports of projected railroads and appraisals of industrial and railroad properties. from to , mr. barnard was receiver of the omaha and st. louis (now wabash) railway, during part of which time he was also president of the alton bridge company, and receiver of the st. clair-madison and st. louis belt line. in the spring of he moved to los angeles, cal., where he lived until february th, , when, after an illness of several months, he died at his home at the age of years. mr. barnard was elected a member of the american society of civil engineers on september st, . he was also a member of the american geographical society. =robert l. engle, m. am. soc. c. e.=[ ] [ ] memoir prepared by o. e. selby, jun. am. soc. c. e. died october th, . robert l. engle was born on december th, . he was a product of the time when opportunities for technical training were few, so that his engineering education was gained largely by contact with actual work. he began his professional career after the civil war, in which he served for two years in the one hundred and forty-eighth indiana volunteer infantry. the first construction work of any note on which mr. engle was engaged was the building of the ohio and mississippi railroad, now a part of the baltimore and ohio system, extending from cincinnati to st. louis. later, and up to , he was connected with the construction of the cincinnati southern railway, cincinnati's municipally owned railway, as division engineer, at ray springs, tenn. this work included several tunnels and other heavy work in the mountain territory. after the completion of the cincinnati southern, mr. engle went west, and was engaged in the construction of the santa fé railroad at trinidad, colo., in the capacity of assistant chief engineer. under his direction the royal gorge hanging bridge was built, and much other interesting work was carried out. mr. engle's forte was location, and in the mountainous regions of the west he found ample exercise for this faculty. from trinidad he moved to santa fé, n. mex. his name is borne by engle, n. mex., now a thriving western town. while still in the west, mr. engle was connected with the mexican central railroad, at chihuahua, mexico, on construction work, and with the denver and rio grande railroad. it is thus seen that he played a part in much of the important pioneer railroad development of the mountain region of the west. in , mr. engle began work on the location and construction of the chicago, burlington, and northern railroad, now part of the burlington system, being located at st. paul, minn., as assistant chief engineer of that portion of the line north of la crosse, wis. later, his jurisdiction included the whole line. during and a part of , he had charge of the construction of the illinois valley and northern railroad, as chief engineer, at la salle, ill. in the latter part of he conducted surveys for coal branch lines connecting with the chesapeake and ohio railway, in the mountains of west virginia. beginning in september, , mr. engle was resident engineer on the construction of the louisville and jeffersonville bridge over the ohio river. during his term of service the substructure, involving several deep pneumatic foundations, was built, and parts of the approaches were erected. during his stay at louisville mr. engle was selected as arbitrator in a matter of disputed classification between the company and the contractor for the pike's peak rack railroad, and effected a satisfactory settlement. among other things his later service included location work on the tennessee central railroad, in ; location and construction work for the missouri, kansas and texas railroad, in arkansas; and construction work on the tidewater railroad, now the virginian railway, at princeton, w. va. at the time of his death he was employed as engineer for the contracting firm of carpenter and boxley, at johnson city, tenn. with the death of robert l. engle, the profession loses one of those sturdy, self-made engineers, to whom the country is largely indebted for pushing railroad construction overland and through the west. in character, rugged like the mountains with which he was associated, he was still the gentlest of souls to those associated with him in subordinate capacities. the writer knew him as chief and friend for many years, and cannot recall any departures from the lines of the highest dignity, rectitude, good habits, and good nature. mr. engle was a member of the engineers' club of cincinnati from the time of its organization. he maintained his home in cincinnati for twenty-one years, while his engagements kept him at various other places. on february th, , mr. engle married miss sallie mcqueety, of cincinnati, and is survived by her and their son and two daughters. his family and social relations were most happy, although his enforced absences from home kept him from much of the social contact which his qualities deserved. mr. engle was elected a member of the american society of civil engineers on september th, . =charles herbert deans, assoc. m. am. soc. c. e.=[ ] [ ]memoir prepared by emil diebitsch and edwin s. jarrett, members, am. soc. c. e. died march th, . charles herbert deans was born in chester, delaware county, pa., on november th, , and died at his home in ph[oe]nixville, pa., on march th, . his father, charles woodbury deans, was prominent in educational work, and was active in the early organization and in the popularization of the common school system of the state of pennsylvania. on his father's side mr. deans was descended from the deans and sterling families, who, immediately following the war of the revolution, emigrated from connecticut to susquehanna and wyoming counties, pennsylvania. his mother was priscilla lyons williams, of chester, delaware county, pa., who was descended from the lyons family of new jersey and the williams and pennell families of pennsylvania. from both his father and his mother mr. deans inherited a taste and aptitude for study. his youthful environment was among books and in an atmosphere which naturally encouraged the desire he early formed to fit himself for a professional life. his education was begun in private schools, but later he attended the public schools, and was graduated from the high school at ph[oe]nixville, pa., in . he spent the next four years in practical work, learning business methods, becoming an excellent and accurate accountant, and familiarizing himself, in the works of the ph[oe]nix iron company, with mill and shop methods and practice, and the metallurgy of iron and steel. in , mr. deans entered lehigh university, well prepared in his studies, with a mind ripe for the absorption of further knowledge, and a temperament for enjoying to the utmost the four years of university life before him. he was a good student, standing well up in the first quarter of his class. he was elected a member of theta delta chi fraternity, was one of the editors and assistant business manager of the college annual in his junior year, and business manager of the engineering journal in his senior year. he was graduated in with the degree of c. e. as a boy mr. deans was fond of games and all healthy outdoor sports. he was a lover of nature and of animals, fond of fishing and hunting, and was never happier than when roaming the beautiful woods and mountains of his native state. with such tastes it was natural to find him, in his college days, a participator in, and an enthusiastic supporter of, athletic games. not only in athletics, but in all things pertaining to lehigh university, mr. deans was a most loyal and enthusiastic son of his alma mater, both at college and after he had gone out into the world. he thoroughly appreciated the benefits derived from his technical training, and was so eager that others should share them, that early in his business career he advanced sufficient funds to two ambitious young men to carry them through lehigh. immediately after graduation mr. deans entered the employ of sooysmith and company, the well-known foundation engineers and contractors. he rapidly advanced to positions of responsibility with this company, and, in , became its vice-president and chief executive officer. when, a year or two later, charles sooysmith, m. am. soc. c. e., retired from active business, mr. deans organized, from the sooysmith and company staff, the engineering contract company, of which he became president. pressure of business seriously undermining his health, he was forced to give up temporarily all work in , and to spend the next two years in the mountains of northern pennsylvania. on regaining his health, he associated himself with the firm of john monks and son, of new york city, and, at the time of his death, he was second vice-president of that company. while under his executive charge, both sooysmith and company and the engineering contract company, constructed a number of the most important bridge foundations in the united states, and the former firm first successfully introduced pneumatic work in the foundations of the modern high office buildings of new york city, notably the manhattan life, washington life, standard oil, and empire buildings on lower broadway. at the time of his death, mr. deans was in full charge of the building of the piers of the reconstructed baltimore and ohio bridge over the susquehanna river, at havre de grace, md. in the early years of his connection with sooysmith and company, mr. deans was employed on work in the field, rising from subordinate positions to that of superintendent in responsible charge of work. during this period he acquired an intimate and practical knowledge of foundation construction, and his subsequent career gave evidence of the value of this training. being thus well-equipped, mr. deans soon became notable as a business engineer. his judgment on all substructure engineering problems was quick and keen, his thorough technical knowledge being supplemented by his penetrating practical sense. his business ability was of a high order, and his efficiency was largely increased by his industry and methodical habits. as a negotiator, he was in the first rank. his quick appreciation of the essentials in business transactions, his fertile resource in the most complicated financial dealings, his patience and persistence in the face of discouragement or delay, and his inflexible determination when once his decisions were reached, were qualities which placed him in the highest rank as a contracting engineer. to those with whom he came in close contact, mr. deans will always be remembered as exemplifying the ideal combination of technical training with business efficiency. he lightened the seriousness of his business transactions with a quick sense of fun, a fondness for a good story, and an infectious good humor. his genuine interest in the work of his associates and his unfeigned delight in their success won him many friendships which lasted throughout his life and which now keep his memory warm in the hearts of those who were fortunate enough to know him intimately. strong of will, keen and clear-sighted in business transactions, loyal to his friends and to the interests entrusted to him, he was, above all, a genial, honorable, many-sided man, who loved his fellow men. mr. deans leaves a mother, mrs. charles w. deans, of ph[oe]nixville, pa., a brother, john sterling deans, m. am. soc. c. e., chief engineer of the ph[oe]nix bridge company, and two sisters, mrs. r. barclay calley, of seattle, wash., and mrs. elmer e. keiser, of tacony, pa. in , mr. deans married miss helen arnold of west chester, pa., who, with two sons, charles woodbury, aged , and malcolm arnold, aged , survives him. mr. deans was elected a junior of the american society of civil engineers, on december d, , and an associate member on may th, . =william meier, assoc. m. am. soc. c. e.=[ ] [ ] memoir prepared by william a. theodorsen and e. james fucik, associate members, am. soc. c. e. died february th, . william meier, the son of the reverend jacob l. and mary meier, was born in muscatine, iowa, on april th, , the family moving to chicago, ill., in the same year. mr. meier received his education in the public schools of chicago and at the university of illinois, from which he was graduated in , with the degree of b. s. in civil engineering. after his graduation, mr. meier was engaged with various firms, principally in bridge and structural work. for a time he was with william m. hughes, m. am. soc. c. e., and in january, , he entered the service of the scherzer rolling lift bridge company, as assistant in the chicago office; and later was appointed assistant engineer and eastern representative, with headquarters in new york city. at the time of his death, mr. meier was employed in the bridge department of the chicago and north western railway. on february th, , in diving from a spring-board, in the natatorium of the young men's christian association, he struck his head against the side or bottom of the tank. when his body was taken from the water, life was extinct, and all efforts at resuscitation were futile. mr. meier took great interest in all that pertained to his profession. he was elected an associate member of the american society of civil engineers, on june st, . he was also a member of the western society of engineers.