vj.EcrKimi. Handbook -\V MEMORANDUM. This electrical handbook is one of a series of ten similar handbooks prepared under the aus- pices of the American Institute of Electrical Engineers by the local Reception Committees in the Cities of Boston, New York, Schenectady, Montreal. Niagara Falls, Chicago, St. Louis. Pittsburg, Wash- ington, and Philadelphia. These are the stopping places on the circular tour organized by the Institute for the reception and entertainment of its foreign guests who visit the United States in connection with the International Electrical Congress at St. Louis, Septem- ber 12th to 17th, 1904. It is hoped in these hand- ^^ books to present short historical sketches of the cities " visited and a rapid survey of the power plants and important electrical industries along the route. Chicago. No. 276 '-■jn^e/n-fd- «k. id LOCAL RECEPTION COMMIHEE BOSTON MASS. THE CHICAGO ELECTRICAL HANDBOOK Being a Guide for Visitors from Abroad Attending the International Electri- cal Congress, St. Louis, Mo. September, 1904 Printed for Private Circulation Cljicap Issued under the auspices of \ The Am erica n Institute of Electrical Engineers\ 1904 COPYRIGHT, 1904 BY THE AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS BINNER-WELLS CO. ENGRAVERS AND PRINTERS CHICAGO TABLE OF CONTENTS General Introduction 5 Electric Light and Power Service Central Station Situation in Chirar/o 21 Chicago Edison Company 37 Commonwealth Electric Compam/ 67 Electric Transportation and Telephone Service Elevated Railwaij.'i' of Chicago 93 Illinois Tunnel Company 97 Aurora, Elgin and Chicago Railway Ill Chicago Telephone Company 115 Electrical Manufactures Western Electric Company 127 Water Power and Electrical Transmis- sion The Sanitary and Ship Caned 147 Some Interesting Applications of Elec- trical Power Electrically Operated Pumping Station at Bridgeport 169 Packing by Electricity 175 Electricity in the Manufacture of Harvesting Machinery 177 Electric Fire Pump 183 Electrically Operated Lift and Draw Bridges 187 ir. ir. Kimball Company 195 Illinois Steel Company 197 INTRODUCTION INTRODCTTION The pvirpose of this handbook is to furnish visiting delegates of the International Electrical Congress with a concise description of Chicago and its larger electrical interests. Inasmuch as many of the delegates are doubtless unfamiliar with Chicago's history, it may be permissible to offer a very brief resum^ of the city's origin and growth. The early French cartographers spelled C-hicago in wliatever way pleased their fancy — Chickagu, Chikagou, Chicago and Chicaqu. Historians of a later date have been even more decorative in their definitions of the word. Without attempting to enter into the subtleties of Indian terminology, it may be sufficient to quote a statement made by Dr. William Barry, first Secretary of the Chicago Historical Society, who says: "Whatever may have been the etymological meaning of the word 'Chicago,' in its practical use it probably denotes strong or great. The Indians applied this term to the Missis- sippi river, to thunder, or to the voice of the Great Manitou. Edward Hulibard, the genealogist, adopts a similar view and says that the word Chicago, in its appli- cations, signifies strong, mighty, powerful." The aboriginal owners of Chicago were the Miamis. Louis Joliet and his fellow explorer, the Jesuit mission- ary, Jacques Marquette, were probably ^"'"'i/ ,. the first white men to land on the site of Exploration Cliicago, when they explored the Illinois river in 1673. At any rate, the adventurous Robert Cavelier, Sieur de La Salle, has left us a very clear account of his trip down the Mississippi in 1681, via the "Chicago portage." This portage is noteworthy because it determined the location of Chicago. It was the shortest and easiest passage from Lake Micliigan to the 7 8 I n t to (I II c t { o n Mississippi, and the red man liad used it from time immemorial. Joliet at once perceived the possibiHty of going from the Great Lakes to the Mississippi in boats, and advised tlie Canadian authorities that "there would be but one canal to make, by cutting half a league of prairie, to pass from the lake of Illinois (Lake Michigan) into St. Louis river (the Desplaines), which empties into the Mi-ssissippi." La Salle, revisiting the place in 1682, ridiculed the scheme as impracticable and poked fun at Joliet's "proposed ditch." Two hundred and twenty- seven years later the proposed ditch was dug. It cost $42,000,000 and is known simply as the sanitary and ship canal. When it was opened hi 1900 the current of the Chicago river was reversed, the waters of Lake Michigan were poured into the Mississippi and the Great Lakes were linked by a navigable route to the Gulf of Mexico. Louis Joliet's right to a charter membership on the drainage canal board would seem to be beyond dispute. In the summer of 1803 Captain John Whistler, L'.S.A., then stationed at Detroit, was ordered to proceed to Chicago with his company and construct Fort Dearborn ^ fort, which was named Fort Dearborn, Massacre [^^ honor of General Henry Dearborn, then Secretary of War. At this time the settlement comprised three or four cabins, occupied by French-Canadian traders and their Indian wives. In 1812, owing to reverses sustained by the Americans at Fort Mackinac, Captain Nathan Heald, who succeeded Captain Whistler as commandant of the garrison in 1810, was ordered to evacuate Fort Dearborn and return with his force to Detroit. Shortly after their departure from the fort, the little band of soldiers and settlers was way- laid and massacred bj^ hostile Indians. The site of this tragedy, at what is now the intersection of Prairie avenue and Eighteenth street, is marked by a monument com- memorating the heroic and hopeless struggle of these brave pioneers against an overwhelming force of savages. The seed of a great city, however, had been sown, and I N t r () d i( (■ f I <) n 9 neither the massacre of 1812 nor tlie liolocaust of 1871 could destroy it. Civilization had come to stay in Chi- cago, and savagery was to lie thrust thenceforth farther and farther westward into the retreating wilderness. Fort Dearborn was rebuilt on a larger scale, the settlers returned in greater numbers, and the close of the Black- hawk War in 1832 marked the collapse of Indian suprem- acy east of tlie Mississippi. In 1833 Chicago, liaving barely the required number of 150 inhabitants, became an incorporated town, and four years later was incor- porated as a city, with an area of about ten square miles. That was sixty-seven years ago. In 1903 the population of Chicago, according to the city directory, was esti- mated at 2,241,000, and its area a trifle imder 200 square miles. That such a rapid growth should be possible within the span of an ordinary lifetime, is a fact, the simple statement of which speaks eloquently of Chicago's unconquerable spirit. The great Chicago fire, which occurred in the autumn of 1871, practically wiped the city off the map, destroy- ing three and one-half square miles of The Great Fire property, \'alued at about $200,000,000, and sacrificing over 200 lives. At that time the total population was about 300,000, but out of the ashes of the old city a new one soon arose, larger and more enduring than its prototype. In 1870 the popu- lation of Cliicago was 298,977; in 1880, 503,185; in 1890, 1,099,850; in 1900, 1,698,575; last j-ear it was estimated at 2,241,000. The foregoing figures predicate something more than mere growth of population and increase of area, for though Chicago is the second largest American city in point of population, it has few superiors in the magni- tude and importance of its manufacturing and mercan- tile activities. The commercial strength of Chicago is derived not alone from its strategic position as one of the largest in- dustrial centers of the United States, nor from the ramifications of its extensive operations in food prod- 10 I n f r o d u c t i o n ucts, cereals, steel rails, machinery and other merchan- dise, but from the fact tliat the termini of twenty-six railroads, aggregating over 84,000 miles of railway (or more than one-third the total railway mileage of the United States), are here focused to pour their concen- trated wealth of traffic upon the Chicago market. A large amount of this freight is also handled by the fleets of the Great Lakes, which, plying between Chicago and eastern ports, carry immense quantities of grain, lumber, coal, ore and other products, the tonnage of vessels entering and clearing the port of Chicago amounting to 15.307,635 in 1903. The down-town business district of Chicago is confined to a remarkably small and congested peninsula bounded on three sides bj^ Lake Michigan and Modern Chicago branches of the Chicago river. In the heart of this square mile of sky-scrapers lies the retail shopping district, seven blocks in length and five blocks wide. Here, in an astonishingly short space of time, the visitor may traverse the principal thoroughfares and inspect the city's leading business and public institutions. Michigan avenue, which borders the lake, and is separated therefrom by Lake Front Park, is devoted principally to hotels, clubs, musical colleges and studio buildings. Here are located the Art Institvite and the Public Library; here also are to be erected in the near future a temple of music for the Chicago Orchestra, and, v.hen tlie park is extended and completed, a permanent home for the Field Columbian Musevmi, now housed in the old World's Fair Art Building at Jackson Park. West of Michigan avenue is Wabash avenue, a high- wny for the down-town loop as well as for surface lines penetrating the South Side, and the home of many large wholesale concerns. One block west, Wabash avenue is paralleled by State street, the main artery and principal sliopping thoroughfare of the city. At its northern end stands the vast bulk of the famous Masonic Temple, from tlie roof of which, 354 feet above the street level, a fine •/JS::^^^:^' ; 12 I nt r () d u ct I o n panoramic view of the city and lake may be enjoyed. The whole block immediately south of the Temple is occupied by the several fine buildings of Marshall Field & Company, unquestionably the largest and finest mercantile establishment in America. This immense retail store has a floor area of twenty-three acres, is equipped with fifty elevators, lighted by an equivalent of 40,000 sixteen candle-power lamps, and is frequently visited in one day by as many as 200,000 people. Many other large retail houses and office buildings line both sides of State street, from Lake street on the north to Congress street on the south, and midway is situated one of Chicago's largest and oldest hotels. Dearborn street, the next street west, is walled in by such an imposing double line of sky-scrapers as to suggest a deep and wind-swept mountain gorge. On this street the First National Bank Building is now in course of construc- tion; when completed it will contain 9,000,000 culnc feet of space. On a square formed by the intersection of Dearborn, Jackson, Adams and Clark streets, the massive granite Government building is now nearing completion, its tremendous gilded dome towering far above the surrounding structures and dominating the whole city. Three blocks north, between Clark and La Salle streets, are located the municipal and county administration buildings, and on La Salle street are the Stock Exchange, the Board of Trade, the Illinois Trust and Savings Bank Building and a number of other fine structures devoted largely to lianking and insurance interests. Still farther west lies a portion of the city's wliolesale district, and beyond the river, in zones of varying size, are manufacturing settlements and guburl)an residence districts extending north, south and west for distances ranging from twenty to tliirty miles. The environs of Chicago are encircled by a beautiful system of parks and boulevards, the scope of which is constantly being enlarged to keep pace with a rapidly increasing population. .\ complete circuit of the parks / n t r () (I u rf i o n 13 and their coiiiiectiiiff IjoalevarJs iiuiy l)e made very pleas- antly in three or four hours, covering a distance of forty or fifty miles, and this is a very popular The Park and automobile trip for visitors who desire Boulevard * i * • i- r ^i -^ > .1 .• System to obtain a glimpse of the city s a'sthetic development as expressed in its places of amusement and outdoor recreation, its picturesque drives, artistic homes and fine educational institutions. The University of Chicago, located near Jackson Park, is one of the youngest and largest universities in the United States, and its noble groups of buildings are models of architectviral beauty. Four thousand five hundred students attended the university in 1903; the present endowment is $15,000,000, but the powerful support of Mr. Rockefeller and other wealthy and pub- lic-spirited men will proliably quadruple this amount within the next decade. Chicago is exceptionally rich in her technical schools, chief of which are the Lewis Institute and the Armour Institute of Technology. The latter Facilities'^ school, located at Thirty-third street and Armour avenue, was founded by the late Philip D. Armour, and its president is the Rev. Frank W. Gunsaulus. The institute offers a very broad and thorough four-years course in the various branches of engineering, and connected with it is the American School of Correspondence, which presents similar courses for the instruction of students who are unable to attend the institute in person. Lewis Insti- tute, founded under the will of Allen C. Lewis, is a school of engineering and the applied arts, dedicated to the teaching of science, literature and technology. It has a total attendance of two thousand five hundred students, over half this number attending the evening classes. It has an endowment of $1,000,000 and receives an income of $50,000 from tuition fees. The institute is under the directorship of George N. Carman, and is located at the intersection of West Madison and Robey streets. Chicago has built up a \ery efficient public school 14 Introduction system. '' \ ^.vliich it spends over $12,000,000 annu- ally for the free education of its children. During the first half of 1903 *he enrollment showed a total attendance of 258,968 pupils and 5,444 teach- ers. Over $500,000 is disbursed every month by the city to the teachers and officials of the Board of Education, as against $775,000 paid to all other city employees. These figures are particularly significant and interesting, since they serve to explain, in a great measure, the wonderful ease and celerity with which Chicago digests and assimilates the perennial juvenile increment of its large foreign population. From the kindergarten to the high scliool, these children of two- score alien races rub elbows with the sturdy native stock and not only become thoroughly "Americanized" them- selves, but carry home to their elders the broad and wholesome lessons of right living and thinking which they have absorbed at school. There are 564 publications issued in this city, includ- ing 33 newspapers (printed in twelve languages), 46 religious periodicals, 35 scientific jour- Newspapers and ,jj^ig ^^j^^j 32 literarj^ papers and maga- zines. The total circulation of the 15 leading daily newspapers is, 2,161,782 copies. Space will not permit more than the mention of Chi- cago's organized charities and numerous hospitals, nor more than a passing reference to the sociolog- ical work being carried on at tlie well-known set- tlements of Hull House and the Chicago Commons. The former was founded in 1899 by Miss Jane Addams and Miss Ellen Starr; it now occupies commodious quar- ters in a group of eight buildings situated at 335 South Halsted street, and its work is devoted to training and up- lifting the polyglot population of that congested district, with notable success. The Chicago Commons conducts a similar crusade of education and social development at the corner of Grand avenue and Morgan street, under the leadership of Professor Grahain Taylor, a broad-minded economist and untiring worker for civic betterment. I n t r o d u c t i o n 15 Chicago is excellently equipped with thr3e 'arnje public libraries — the Chicago, the John Crerar and the New- berry — the two latter being reference libraries solely and the former a reference and circvilating library. 1 he Newberry occupies an imposing granite edifice on the north front of Washington Square, and its spacious rooms and book-lined alcoves are a favorite haunt of students and literary workers. It contains 260,273 volumes in its various departments of art, science and letters. The Crerar, organized in 1895, is a fine scientific library founded by the will of the late John Crerar, a wealthy and philanthropic citizen of Chicago. It has at present a collection of about 103,000 volumes, devoted almost wholly to the natural, physical and social sciences and their applications. Its endow- ment amounts to $3,400,000 and it occvipies temporary quarters in the fifth and sixth floors of the Marshall Field building, pending the proposed erection of a beau- tiful permanent home on Lake Front Park. The Chicago Public Library, located at the corner of Washington street and Michigan avenue, represents the highest type of modern methods in library equipment and the hap- piest blending of utility with classic design. Its exterior is severely simple, but this only accentuates the contrast when the visitor passes within its portals and stands on the threshold of its lofty entrance hall, leading to two stately stairways in pure white marble, inlaid with exquisite mosaic patterns of green and gold. It is prol)- ablyone of the most artistic examples of interior decora- tive effect in the country. At the close of the library year. May 31, 1903, the Public Library contained 285,000 volumes, and its aggregate circulation for the year was 1,609,983 volumes, not including the use of reference works. It is an exceptionally strong library in its chosen field, and through the medium of its sixt}'-eight branch stations it keeps in close touch with the remotest dis- tricts of the city. In addition to the above-mentioned libraries, Chicago has a number of others, more or less public in their privileges, connected with the Field 1() I nf rod u ct i o n Columbian Museum, Lewis Institute, University of Chicago, Northwestern University and other institutions. Such a liost of noteworthy plants, places and buildings are located in and around Chicago that it is impossible to mention all of them and unfair to make Stock Yards invidious distinctions, so that many mat- ters of interest must be either touched upon very cursorily, or wholly omitted. But no account of Chicago would be complete without some reference to the gigantic live stock market known as the Union Stock Yards, and the various associated packing concerns that constitute in their entirety the greatest center of meat products in the country. The Stock Yards district com- prises a tract of about 500 acres, hedged with huge pack- ing plants, crosshatched with 22,000 cattle pens, grid- ironed by railway tracks and traversed in all directions by overhead viaducts. Half a million cattle, horses, sheep and swine are often handled here in one day. The Stock Yards give direct employment to 50,000 men and handle fifty per cent of all the cattle slaughtered in this country. In 1903, Chicago received 16,232,000 animals, valued at $295,217,000. The conversion of this tremendous amount of raw material into the innumerable primary and by- products for which Chicago is famous, is principally accomplished by Armour & Company, Swift & Company, Libby, McNeill & Libby, Nelson Morris ct Company and several other large firms, whose various industries in packing and canning are collectively one of the main sources of the world's meat supply. The Stock Yards district is connected with all railways entering Chicago by the Chicago Junction Railway Company, which has two belt lines around the city and about 300 miles of trackage. A word in conclusion. According to tlie census of 1900, the annual value of Chicago's manvifactures was $8SS,7.S6,311. Carl Buck, Professor of Sanskrit and Indo-European comparative philology at the University of Chicago, in his work on the "Linguistic Conditions of (Chicago," enumerates over forty foreign languages that I nt roducf i o 7i 17 are spoken in this city. Here, then, is tlie extenuation for many of the crude and unlovely conditions that are, luifortunately, more obvious to the casual visitor than the promise of better things which they foreshadow. Chicago, the city of factories, is also the rendezvous of all nationalities. At present it is passing through a period of social and industrial evolution; it has had little time, as yet, for dreams and ideals, but it is begin- ning to realize the potentialities of its environment, and plans are now well under way for the conversion of its downtown lake front into parks and pleasure grounds, which will eventually conceal the existing wilderness of waste land and railway tracks. Chicago's corporate existence as a city covers only sixty-seven years; its faults are the faults of youth, and any final conclusions drawn from present conditions should be tempered by this consideration. ELECTRIC LIGHT AND POWER SERVICE Central station Situation in Chicago; General Features. Since the earliest days in the history of electrical development, Chicago has been a prolific field for the application of electricity to the requirements of light and power service. Turning back to fifteen years ago, we find the "Chicago Edison Company," the "Chicago Arc Light and Power Company," and then soon springing up the "Englewood Electric Light Company," and others innumerable. To-day there are two companies, the "Chicago Edison Company," and the "Commonwealth Electric Company," the latter having now outstripped the former in gener- ating if not in distributing facilities. The Common- wealth Electric Company, a composite formation of the many earlier electric light enterprises, owes its birth to the economical possibilities of combination. This unification occurred about six years ago, and since that time entire harmony has characterized the co- working of these two companies: the Chicago Edi- son Company generating and distributing electricity in its territory and the Commonwealth Company doing likewise in its own territory. The latter, born in a period of rapid electrical development, was supplied in its earlier years with much of its electrical energy by the former. To-day this situation is reversed and the Chicago Edison Company is being supplied with alter- nating high tension current for its Converting Sub- stations by the Commonwealth Electric Company from its new generating center, the "Fisk Street Station." Of the entire 9,000-volt output, the predominating generated product of the two companies for the twelve 21 22 The Chicago months preceding July 1. 1904, 69.7 per cent was distributed on the Edison three- wire network; 14.7 per cent as 500-volt direct current for street railway / / / / / / ^ / 3 / / \\ i / / /i / \ ^ Y // V \ / 4 f / ^f f lA ^ i t, ^ / / > / _,ljt Jf& / t:_:" ^GJ •as... '■ -"'"T' \ ^«» W01.T """"+"■" SHOWING VARATIONS IN TOTAL AND CLASSIFIED GENERATED OUTPUT work, and 15.6 per cent as alternating current for lighting and general power. The increase since 1888 in total load on the Chicago Edison and Commonwealth Electric companies' systems is illustrated above, which also shows the variation in E I e r t r i c (I I H a n d hook '^.S annual maximum demand on the different classes of generated output. It is to be noted that since the development of the 25-cycle transmission system which has taken place since 1897, and the consequent centraliz- ing of generating capacity in the Harrison street station of the Chicago Edison Company, and more recently in tlie Fisk Street Station, the proportion of electrical energy generated as 25-cycle current is rapidly increasing. During the year 1904, the amount of energy generated as 250-volt direct current and also that generated at 60 cycles has begun to decrease, due to the shutting down of the Washington and 56th street stations for a large portion of the day during ten months in the year. In general, the policy of these Central Station Com- panies is to generate their output at 9,000 volts in large central stations by large units and to transmit this output to the substations at this pressure. In the sub- stations supplying the downtown districts — where 50 per cent of the load is power, or, in comparison with the total generated load, 14 per cent is elevator motors and 21 per cent general power — low-tension, direct-current dis- tribution is used, the conversion being effected by step- down transformers and rotaries. Thus the character of the load determines largely the kind of distribution. From the description of substations given later, it will be seen that the battery capacity installed at the one-hour rate is about 30 per cent of the total generating capacity, which insures the system against interruption, a factor paramount in central station service. The policy for the residence districts, where the percentage of lighting load is high, is to install frequency changing sets and to distribute 60-cycle current at 2300/4000 volts; a practice again admira})ly adapted to the load and the district supplied. GENERATING AND TRANSMISSION SYSTEM The Chicago Edison Company supplies botli the busi- ness and older residence sections of the city of Chicago with direct current, employing for this piu'pose the well- 24 The Chicago known 1 15/230-\"olt Edison three-wire system installed under ground. Service is supplied by this company for all purposes: lighting, general power and elevator power proportionately in the order named. The company serves 17,000 customers with 1,330,000 lights and 44,270 horse-power in motors. The Chicago Edison territory is divided into four dis- tricts all interconnected by a vast network of under- ground conductors, the Chicago river being crossed by submarine cables and undermined by tunnels to effect this juncture. Four stations with a total capacity of 23,000 kilowatts, and eighteen substations equipped with 18,000 kilowatts in rotary converters and 12,500 kilowatts in batteries (one hour rate of discharge), supply these districts with current. In addition a supply of 10,000 kilowatts is available from the Commonwealth Electric Company, thus insuring excellent service for the customers of both companies. The Chicago Edison Company has remaining only one large generating station, the Harrison Street Station, which is yet the mainstay of this company. The Wash- ington Street Station, formerly interesting from the standpoint of adaptability of an old plant to a modem system and ranking second to Harrison Street, has been stripped of much of its power, a large, new, rotary substa- tion adjacent having been substituted to provide direct current for the Edison three- wire system at this point. Two other so-called subsidiary steam plants (combined generating plants and substations), viz., the North Clark Street Station and the Twenty-seventh Street Sta- tion, complete the list of generating plants of the Chi- cago Edison Company. The transmission system of the Ch icago Edison Company is a striking example of evolution and shows clearly the wonderful power-transmitting possibilities in a crowded business district of a great municipality, where safety, reliability and appearance are factors of primary im- portance. The high tension transmission system of the Chicago Edison Company' from the generating sta- A u rS ■* o (0 o -a 0) cn *" u M _ ? I S J» D 3 X t: o 7 ? (ft • > > D n > > f- Z N T m K =" Tl > > ^ n o n o *^ 3) > ?; ^ 3 n n ^ (J r- O I o (0 •; H n H 0) 0) H (D O 3) Z H o r I 0) H o o r- o 55 n (ft H *> i5 (ft O z (ft -1 o (ft H c w (ft O H 5 r 3 3 a 3 3 3 3 3 i c M > m !i^ d ''I ? o H H 2 , 3 3 3 a . 3 - . - - > i O z —I x> ^ o z C/) So c/> cr OD CO —I x> o STATIONS & SUB STATIONS CHICAGO EDISON COMPANY /ICK ST. SU8 STATION . DIVISION ST •■ . CLARK ST " OHIO ST. KIN2IE ST. ILLINOIS ST HADDOCK PL - RANDOLPH ST. - ^BORN ST. - ADAMS ST. MARKET ST. LYDIA ST. HARRISON ST. STATION W. 14. TH ST SUB STATION JACKSON BLVD. ■■ STATE ST 21 ST. ST. COMMONWEALTH ELECTRIC COMPANY SUB STATION 20 W.MADISON ST. - 21 MORGAN ST. - 22 FISK ST. 23 FISK ST. STATION 2A 56 TH. ST. SUB STATION 26 HYDE PARK 26 S. CHICAGO EXPLANATION GENERATING STATIONS. US STATIONS DtSTRtBUTING Dl RECT CURRENT AND SUBSIDI f STEAM PLANT. , DISTRIBUTING AL- CURRENT AND SUB* ( STEAM PLANT. Electrical Ha n dbook 25 tions to all substations is installed vuidcrground, and so thoroughly has this system been developed, installed, and protected that it could probably be used without alteration for transmission at twice the present system potential. The transmission system of the Commonwealth Elec- tric Company, employing as it does the same voltage arid frequency, is being rapidly developed in accordance with the same high standard, thus making possible any desired exchange of energy and the best economy in operation, of mutual advantage to the two companies. The Commonwealth Electric Company covers the entire City of Chicago, but thus far has devoted itself almost entirely to the outlying suburban and residential districts, leaving the business and older residence sec- tions to the Chicago Edison Compan^^ All of this large outlying territory is covered by a 2300/-4000-volt, 4-wire, 3-phase, 60-cyole, overhead system of primary distribu- tion, supplied from two subsidiary steam plants, the Fifty-sixth Street and' the Lake View stations, and five substatiorts, the latter receiving energy from the new Fisk Street Station. The accompanying map shows the location of the generating and distributing centers of the two Central Station Companies in the City of Chicago. The pi'oximity of these centers gives at once a fair indication of the relative diensity of the load, at least in the older portion of the city, in which, as previously stated, the distribution is by means of the Edison three- wire direct current system. CENTRAL STATION OPERATING CONTROL The greater possibilities in central operating control of these two great interdependent companies were early recognized. The rapid growth of the business, the intricate char- acter and multiplicity of apparatus employed, made it adA'isable to further concentrate this control of the 26 The C h i ca g o operation of the system and resulted in the creation and maintenance of the office of Load Dispatcher. The duty of the "Load Dispatcher" is to perpetuate operating service and to control the transmission and transfer of any and all "Load," that is, all electrical energy between all stations and substations of the two companies. He is thus particularly responsible for the high potential transmission system and controls abso- lutely the operation of all lines, line switches, and bus bar tie switches which comprise this system. This service is maintained throughout the twenty-four hours of the day and recjuires the services of three men. A chart bearing graphical representation of all trans- mission lines and station busses, and characters repre- senting all generators and switches, is provided for con- venient reference. This chart is manipulated in accord- ance with switches opened or closed or generators put on or taken off the system, and represents at any instant the actual operating conditions of the system as a whole. Direct telephone service with all of the stations is afforded through lines from the many station operators to an exchange which the "Load Dispatcher" alone controls. This in no wise lessens the importance or the vigi- lance required in the operation of the generating stations or their dependent substations, but insures their fullest co-operation and the most satisfactory net result in maintaining central station service. Of great importance also in the operation of these large companies is their system of central coal storage. COAL STORAGE But a few years since it was the practice of the Chicago Edison Company to arrange with some of the big coal handling concerns of the city for the storage of a large quantity of coal whenever there were any indications of an approaching shortage or restriction in coal supply. This method soon proved unsatisfactory, and the recent purchase of a tract of land about 250,000 square feet in E I c cf r I c (I I H a n d h o o k '■27 area, located just across the river from the Fisk Street Station, provides the storage space for about 25,000 tons of coal. This property borders on the river and is en- tered on the south by the tracks of the Chicago & Alton Railroad. The capacity of 25,000 tons is based on the deposit in the shape of an open "pile" or rather a lot of coal simply spread over the groimd from cars on parallel tracks. This can be done either by means of a locomo- tive crane or by shoveling and wheeling. This coal reserve is about two and one-half miles from the Harrison Street Station down the river, and coal can be quickly conveyed to that station whenever the occasion requires. A provision such as this is, of course, essentially an insurance, while economy demands that the coal be handled as infrequently as possible. A large quantity, say 50,000 tons, judiciou.sly l)ought, can thus be allowed to remain here until the emergency necessitating its use arises. The company is thus assured of possession in times of need. STORAGE BATTERIES A furtJier safeguard of almost immeasurable value to their customers , and particularly to those supplied with direct current, is the judicious distribution over the direct current system of a large capacity in storage batteries. The Chicago Edison Company has a large amount of storage battery capacity distributed among its various substations. About 30 per cent of the total annual maximimi demand can readily be carried by the storage batteries for one hour. The type of battery used is uniformly that of The Electric Storage Battery Com- pany, the "Chloride Type." This form of cell is well known, and the continued installation of this same type of battery is the best indication of their satisfactory commercial operation. The installations up to tlie present time have been chiefl}^ for system operation, there being only one for station operation. These different system batteries range in size from plates of the G. type, 33 in number, 28 T he Chicago capable of a 1,000-anipere discharge rate, to plates of tlie H. type, 83 in numlier, capable of 6,000-ampere discharge rate; these discharge rates being on a one- hour basis. These system batteries average about 78 cells, with 23 end cells on either side of the three-wire system, and are generally provided with two or three end cell switches, allowing flexibility in charging, dis- charging and "floating." The "end cells," so called, are those to any one of which connection can be made at will by an end cell switch, thus varj'ing the number in series and giving different potentials. Booster sets, capable of use also as balancing sets, varying in size from 30 to 100 kilowatts (one generator for each 78 cells), provide the necessary charging energy in all cases except one, where specially arranged rotary converters afe em- ployed to give the necessary increased voltage for charging. The booster sets are three-unit type, made by the General Electric Company, and consist of two 60-volt shunt-wound generators, mounted on the same shaft with a shunt-wound, 250-volt n^otor. In charging, one of the generators is connected to the positive and the other to the negati^•e main of the system, thus increasing the pressure to a suitable voltage. Special features in connection with the battery installa- tions of the Chicago Edison Company are apparent at once, whether brought to notice through inspection or detailed study of the battery substations. The electrical indicator, neater, more reliable and more logical than the previously used mechanical device, and the switch- boards, conforming in a general way to the standardized rotary and feeder panels and occupying about one-half the space of the previous American practice, unite to indicate the already recognized permanency of the storage battery in direct current distribution systems. The maintenance of the batteries is wholly in the hands of an expert, a storage battery superintendent who devotes his entire time to this purpose. Tests are regularly made, so that the condition of any cell in Electrical Handbook 29 any battery is known at all tinies. If a cell develops any vital weakness, steps are taken immediately to overcome this defect, with the result that batteries are always in best possible condition. A valuable aid to the upkeep of the batteries is tlie practice of installing double tiers of insulators under the cells. This decreases leakage to ground, facilitates inspection, and permits easy cleaning. Generous venti- lation, either natural or artificial, generally the latter; REPRE.SENT.VTIVP; B.^TTERV ROOM thorough sanitary equipment and careful construction render the largest of the storage batteries of the company unobjectionable tenants in the finest of buildings. The interior of one of these installations is given on this page. The functions of the storage battery, mstalled as these are m connection with a large distribution system, are well known, and a record of the performances of the batteries of this company shows how well they fvilfiU 30 The C h i c a g n their purpose.* Sometimes a demand comes for the service of nearly all the batteries simultaneously, and their "readiness to serve" at such a period makes them 12 2 4 6 8 10 12 „ 2 4 6 8 10 12 LOAD DIAGRAM FOR DOWNTOWN" BUSINESS DISTRICT, SHOWING USE OF STORAGE BATTERY AT PEAK OF LOAD Curves 1, 2, 3, and 4 show loads on Randolph St.. Dearborn St., Market St., and HarrLson St. Substations, re.spectively. a most valuable ally to the central station and an unfail- ing friend to its thousands of cvistomers, large and small. CENTR.\L fTATIOX SUPPLY TO LARGE CONSUMERS Some of the largest wholesale and retail concerns are central station dependencies for their light and power *The diagram herewith shows a typical case of this kind. Elect)- i c a I H a n d b o o k .'U supply, and a detailed description of one of tliese lar^e customers is given lierewitli. One of the most notable examples of the use of electric current for both power and lighting from central station service in Chicago is to be seen on the premises of Marshall Field & Company's large retail department store. Tlie store in (juestion occupies almost an entire city block, antl lias a floor area of 9(10,000 square feet. .M.\RSHALL FIELD & COMPANY .S RETAIL STORE The connected load is 3,C.50 l.orse-power in motors, and an equivalent in lighting of over 40,000 16-candle- power lamps. Fig. 6 shows the exterior of the building. When the problem of providing power and lighting mains arose at the time the new building was erected, it was decided after a most thorough investigation to adopt central station service. Tlie main features which led to this decision were: The high rental value of the space which would be necessary for the installation of an 32 T h e C hi ca go isolated plant, and the necessary coal storage; the difficulties in arranging for a steady supply of coaJ, the location of tlie building being such that coal could only be deliAcred in wagons; and contrary wise the fact that the Chicago Edison Company's system included se\'eral plants and storage batteries, all interconnected, and that service was obtainable through three different channels. Such a mercantile center requires a varied application of power, and the electrical features in the installation preponderate — electrically driven machinery being used almost exclusively. The mains of the Chicago Edison Company enter the basement of the several buildings at fourteen different points, feeders for light and power purposes being separate and so connected that in case of failure of supply through one channel the Ipad .Q9,n be immediately thrown to another. Switchboards jpro- vided with the necessary switches and meters for meas- uring tlie current are installed at .each service. The lighting presents no unusual features ; there is one 16-candle-power lamp installed, or its equivalent, ifor every twenty square feet of floor a,rea. The maximum variation of potential between any two lamps in the building does not exceed twA? volts. The maximum power on any tap circuit is 660 watts. The wiring is done acco>cdii,i;g to the most modern methods, concealed in the walls and ceilings and protected by iron conduit, into which it is drawn. Each circuit is provided with a switch and enclosed fuse. These switches and enclosed fuses are installed on panel boards in fireproof cal)inets on each floor. There are about 200 enclosed arc lamps used in the various buildings, where the violet rays are not detri- mental to their use. Incandescent lamps are used exclusively in the salesrooms, the yellow light from incandescent lamps being more desirable than the arc lamp rays. A very efficient mstallation of incandescent lamps in show cases has been installed. Miniature Jamps are used in mirror reflectors; the reflectors being installed in the top of the glass case, and hidden from view by Electrical II OUTI COMPAM >0T ,J.Z • •KG. A < A roTAU A ^^ i 2 T \ v^ -/ ^ ^ \ \ 1 \ 1 1 1 HpiSK S \ T. ST* V ^ \, N / J ^\ ^i \J \ \ y / i^ |P^^\ TA.-^ ^ HA IRISO i ST.E 12 , 8 10 12 8 ■ AM P M LOAD DIAGRAM, SHOWIXG RELATIVE LOAD ON PRINCIPAL GENERAT- ING STATIONS Four steel stacks, 188 feet in heiglit and 13 feet in diam- eter, furnish the draught for the boilers in the old boiler plant, while another 175 feet in height and 9 feet in diameter performs a similar function for the four boilers in the new annex. One Robbins and two McCaslin conveyors supply coal ^o the 1.000-ton bunkers above the boilers. Electrical Handbook 39 Upon entering the engine room one is impressed with the varying size and the nunil)er of units employed in the generation of electricity, and it is at once apparent how conditions imposed by a rapid business development may be met when demands are made upon engineering concerns. As I)efore stated, there is a great variety of apparatus, yet it is well disposed and the general appear- ance of the station conveys the impression of a great, powerful, though compact, generating center. The EXTERIOR OF HAHRISOX STREET STATION large, double-decked switchboard gallery at the east end of the central aisle has lost none of its attractiveness, although additions and alterations innumerable have created an electrical metamorphosis in its vital parts. Adjacent to it at the south is the alternating current switchboard, with generator and line control panels. These switchboards on the operating gallery are varied in construction and purpose. The old direct current board belonging to the original installation controls the direct current machines, the generator control panels 40 The C h ica g o forming a lower tier, while above these are the feeder panels. Heavy copper construction behind this board and comparatively little secondary wiring for the switch- board are typical of the days of manual control. A later addition, the new high-tension control switch- board, is of the type combining the instrument panel and the operating tajjle. On the instrument panels are indicating meters for the lines and machines, while on the operating table are the controls for the various oil switches. On the engine room floor there is a group of direct current engine-driven units, 6 in numl)er. These are all of the vertical, triple-expansion type, two being of Edison General Electric design (94 revolutions per min- ute) and the other of the Southwark Foundry design and manufacture (120 revolutions per minute). Each is rated at 1,200 horse-power and is direct connected to two 400-kilowatt, direct-current, multipolar, 150-volt, shvmt-wound generators, one of which operates on the positive and the other on the negative side of the three- wire direct-current system. These machines have been in actiA'e operation for about ten years and are still doing good service. Four more Southwark engines, of 600 horse-power each, having two 200-kilowatt, direct-current machines direct connected and of the same type as above, com- plete the Harrison Street Station of the 19th Centviry. Among these are two pair of double-current generators, rated on the alternating current end as 3-phase, 25-cycle, 85-volt machines. The pressure of these machines is raised to 9,000 volts by means of six 150-kilowatt air blast transformers. Next are the large vmits, defining clearly the new epoch in the station's development. The first is a 3,500- horse-power, vertical, cross-compound Allis engine, rim- ning at 75 revolutions per minute, driving a 2,500- kilowatt, double-current generator, giving 170-volt, 6-phase, 25-cycle alternating current or 300-volt direct current. The outnut of this machine is ''stepped up" Electrical H a ti d h o o k 41 to 9,000 volts by mcaii.s of two banks of tliree 450- kilowatt, single-phase, air-blast transformers. jl> The second large unit is a 5,000-horse-power, vertical, cross-compound Allis engine, nnining at 75 revolutions per minute, driving a 3,500-kilowatt, 0,000-volt, 25- cycle, 3-phase alternator. In the annex there is a 3,000-liorse-power horizontal tandem compound, old type, Corliss engine, running at 60 revolutions per minute, and driving through a rope transmission two 1,000-kilowatt, 25-cycle, 9,000-volt, 3-phase generators; and a 2,500-horse-power, vertical, cross-compound Allis-Clialmers engine direct connected to an l.SOO-kilowatt General Electric, 25-cycle, 9,000- volt, 3-phase generator. These alternating current gen- erators are controlled from the panels installed on the operating galler}^ in the main engine room. In the North Annex of the building there is installed a battery for service on the three-wire system on the Chicago Edison Company. It consists of 160 H.-61 cells with discharge rate of 4,500 amperes at one hour rate. There is also a three-unit booster set for charging the battery, which consists of a motor driving two gen- erators of 1,500-ampere, 70-volt capacity, with necessary controlling panels for booster and batteries. The high-tension bus and lir.e system is taken care of in rooms which have been added on the interior of the station. In these structures the different compartments are known as "Switch Rooms," and cable running on insulators beneath the oil switches or practically in the floor of these rooms is employed in the construction of the bus. In these various "Switch Rooms" there have been installed many high-tension solenoid operated switches necessary for control of the generators and of the outgoing lines. W.'\SHINGTON STREET STATION Until six months ago this station was second in impor- tance to the Harrison Street Station. It formerly con- tained a greater variety of electrical generating apparatus 42 The Chicago than any other station of the company. First the series arc equipment of about 2,000-Hght capacity was dis- posed of, the arcs being changed over to constant poten- tial system; next the load carried by a single-phase, alternating-current equipment of about 500 kilowatts was taken over by other stations, until now the last remaining 500-volt power load is being changed over to the three-wire system and nothing remains except the direct-current equipment. The building, rather irregular in outline, constructed of brick in a plain manner characteristic of stations of the earlier type, is situated on the Chicago river at Wash- ington street, and nearer the center of the downtown district than any other generating station. This plant has been operated continuously for the fifteen years preceding May 1st, 1904. Formerly there were three floors to this station, the bottom being the engine room with the direct connected direct current units; the second floor contained the direct current switchboard and other switchboards and all the series arc and 60-cycle alter- nating machinery, while the floor above was used as a counter-shaft room for the belted units on the second floor. The boiler room at the north end still contains six Edgemoor boilers, with a total of 3,250 horse-power, and four Climax boilers of 500 horse-power each. The en- gines and generators still in service are the following: One 1,500-horse-power Tandem Compound Southwark engine, running at 120 revolutions per minute, direct connected to a 1,000-kilowatt, General Electric, 300-volt, direct-current generator. One 1,000-horse-power, cross-compound Williams engine, 120 revolutions per minute, driving a 700-kilo- watt, 300-volt, direct-current generator. Four Porter Allen tandem compound engines, 550 horse-power each, driving eight 225-kilowatt, 135-volt, direct-current generators, half being on the positive and half on the negative side of the system. Three 500-horse-power tandem compound Williams Electrical Handbook 48 engines, 132 revolutions per minute, driving six 250- kilowatt, 135-volt generators. The contemplated operation of this station, with its 5,000 kilowatts of generating capacity, as an annual "Peak" plant, gives a striking illustration of the extent to which it is permissible to carry the principle of "Peak" operation of plants when the more modern and econom- ical plants are available. It is of interest to note that owing to the high cost of coal conveyance to this plant the boilers have been equipped for gas burning, and for several seasons the station has been operated in tliis manner very satisfac- torily. CHICAGO EDISON SUB.STATIONS Prominent among the features of these substations are the switchboards of the company's design, well built, handsome in appearance and as safe as electrical apparatus can be made witii every detail thoroughly worked out. Special attention is given to the back of the switchboards with respect to both the wiring and the provision for working space and also to the protection of cables leading from tliem. On the switchboard itself are installed the best operating devices procurable and every panel is laid out with a view toward simplicity of control, so essential to successful routine and emergency operation. Throughout the direct-current substations, with only a very few exceptions, all rotaries and their auxiliaries are counterparts, the principle type of rotary being the six-phase, diametrically connected, 500 or 1,000 kilowatt unit, with a three-phase, air-cooled transformer. These rotaries operate from a 9,000-volt, 25-cycle transmission system, while current is delivered to the direct-current system at 250 volts. The center of the low-tension side of the three-phase transformers furnislies a neutral con- nection to the system. The transformers are usually three-phase delta con- nected on the high-tension side and six-pltase diametric- 44 T h e C h i ca g o ally connected on the low-tension .side; the parts being all in one case, with an ample opening in the bottom for air blast from below. The six-phase regulators are of the induction type remote controlled and provided w^th an open base for air blast. The rotaries are also installed in such a manner as to permit the upward passage of cooling air. The regulators used with the 500-kilowatt rotary installation are of a capacity of 44 kilowatts, while those used with the 1,000 rotaries are of 88 kilo- watt capacity. Copper bar usually furnishes a neat and efficient means of connection between transformer and regulator and betw'een regulator and rotary. All rotaries are ecjuipped with speed limit devices, w'hile reverse current attachments to the direct current ammeters open the circuit breakers of the rotaries vipon a reversal of current. Some of the speed limit devices are those of the centrifugal type, while others are a purely electrical variety whicli operate upon increase of frecjuency. A few details of the standardized rotary and feeder panels serve to illustrate the general high standard of construction. On the rear of the board the bus construc- tion is such that the positive and negative connections are kept entirely apart, the positive bus occupying the upper and the negative the lower half of the board. Copper bars connect the rotary cables to the buses, while small, well-ordered wires form a continuation of the multiple control cables from the terminal boards to the instruments or controlling apparatus. Thus all cables are kept off the liack of the lioard, making it easily accessible. On the front of the switchboard uniformity in opera- tion of switches and unmistakable indicating and signal devices fvu'nish all that is necessary for reliable operation. Transmission lines are usually brouglit into the sub- stations by different routes from different sections of the generating station. The high-tension bus at the sub- station is usually sectionalized so that immunitj^ against a complete shut-down is obtained. This is further illus- E I c ct r i ca I Ha n d h o o k 45 trated by tlic stutiy of the iii(li\i(lual installations, wherein the large proportion of storage batteries add their reserve strength to the bulwark against interruption of service. The installation of cranes, wherever there is revolving machinery and sufficient liead room, is a valuable feature of these substations, wliicli greatly facilitates the rapid installation or removal of apparatus in cases of emer- gency. DOWNTOWN SUBSTATIONS In the "downtown," or most thickly built up, business district of the city, bounded on the north and west by the river, on the east by the lake, on the 'south by 12th street, known to the company as District No. 1, six sub- stations operate to maintain the three-wire, direct- current service, and since the varying load conditions here affect all of these su])stations similarly, they will be con- sidered together. The proportion between revolving machinery and battery installations is very carefully maintained, and a study of this district, regarding its load factor, its con- nected load, the time of the daily maximum and the amount of the maximum load, with respect to the sys- tem as a whole, could be made the subject of a most interesting treatise. One feature of similarity among the substations, all located on expensive real estate, is the fact that five of the six are located in basements of office buildings. The one exception, the Market Street Substation, occupies the lower floors of a l)Viilding owned by the Chicago Edison Company. The substations known as "Randolph Street," "Dear- born Street," and "Jackson Boulevard," the names in each case being derived from the streets upon which they are located, are equipped with rotaries only. The "Adams Street" and "Haddock Place" substations are equipped with batteries only, while the new "Market Street" Substation combines both equipments. EDISON BUILDING Electrical Handbook 47 Edison Building By no means least in importance among the com- pany's downtown properties is tlie liandsome and sub- stantial Edison Building, containing the General Offices of the company. The basement and rear portion of the first floor contain the Adams Street Substation. The site of the present building, 139 Adams street, marks the location of one of the company's earliest endeavors in the field of electric lighting, although noth- ing of that historic plant now remains. The Edison Building, of moderate height and with large, towering office buildings on either side, presents the strong yet refined forms of the French Renaissance, and has a facade of strong individuality, commanding attention by its richness and beauty of detail, rather than by its bulk. This facade is of Milford pink granite, the surface for the first two stories being highly polished, while the upper portion to the top of the parapet wall is ten-cut work. Above this is a cresting and a large cen- tral motive of terra cotta, and, crowning all, a Mansard roof of red tile. The walls and ceilhig of the entrance hall are of English vein Italian marble, and the floors of marble mosaic. The stairs to the second story are of marble, with a heavy wrought-iron balustrade. The executive offices of the company are located in the front portion of the building, on the fourth and fifth floors. The Directors' Room, on the fifth floor, is in Italian Renaissance style, with panels of mahogany wainscoting twelve feet high and coved ornamental stucco ceiling. A feature of the company's general office building is the Employes' Library and Meeting Room, which is wainscoted five feet high in dark English Oak, with green walls above, and has a floor of quartered oak. The entire building is occupied by the offices of the various departments of the company, among which might be mentioned the Contracting, Inspection and Construction Departments on the second floor, the Accounting Department on the fourth floor, the Pur- 48 T h e C h i c ago Electrical Ha n d h o o k 49 chasing and Supply Departments on the fiftli floor, the Operating and Engineering Departments on the sixth floor, and various other departments located tlirovighout the building, with particular reference to their co-opera- tion with the foregoing and their work and relations with the public. Adams Street Substation The "Adams Street" Substation, located at the heart of the business district, ranks first b}' reason of its seniority and tlie amount of output that it distributes. DISTRIBUTION ROOM, ADAMS STREET It was originally intended as a distributing center for the direct-current generators at Harrison street, which office it has maintained through the epoch of modernizing which the system has undergone. Current is supplied to the bus bars of the distributing switchboard by a trunk line from the Harrison Street Station, of a circular millage amounting to 63,000,000 c. m. and a length of 3,400 feet, and is distriliuted by means of feeders, -47 in nvmiber, and of sizes varying from 350,000 to 1,000,000 50 The C h i ca g o c. m. Page 49 shows the arrangement of tlie switch boards in this substation. Three batteries, averaging 154 cells per battery, with a vuiited capacity of 27,000 amperes at 1^-hour dis- charge rate, or 8,400 amperes at the 8-hour rate, have been installed in this substation, making a batter}^ instal- lation of unusually large size. A three-unit booster set with a 300-liorse-power motor, driving two 100- kilowatt generators for charging tlie batteries, completes the equipment. -'fjtf' INTERIOR OF RANDOLPH STREET SUBSTATION Randolph Street Suhstation A 3,000-kilowatt substation in the basement of one of the city's largest office buildings, with headroom pre- venting the mstallation of any units larger than 500- kilo watts and with a single consumer, just across the street, having a connected load of 40,000 lamps and 3,000 horse-power in motors — such are the unusual con- ditions defining the Randolph Street Substation. An interior view of this substation is shown above. Installed about three years ago, and containing at Electrical Handbook 51 pres^piit five 50()-kilowatt rotary converters, with a 100- kilowatt, 125-volt balancing set arranged to be thrown to either side of the tliree-wire system, this substation operates to maintain the service in the northeastern part of the downtown district. Tlie j^lans admit of an increase to an ultimate capacity of 6,000 kilowatts in rotary con- verter units. Dearborn Street S^ihstation While really a modern plant in every detail of equip- ment, this is the oldest of the company's downtown rotary substations. Like the Randolph Street Substa- tion, it is installed in a basement, and it required a great deal of ingenuity to get all the desired apparatus in place. At present five 500-kilowatt rotary converters supply the central portion of District 1, this station being very centrally located. This substation was installed about four years ago, and has reached its limit in ca- pacity. Market Street Street Substation One of the most important, the n.ost recently installed, and the finest in point of structural ensemble is the Market Street Substation. This plant is located in the basement and on tlie first and second floors of a fine eight-story steel Iniilding, which, with an imposing plate glass and stone front, makes the I)uilding by far the handsomest structure in the vicinity. An exterior view of this building is shown on page 52. Four 1,000-kilowatt rotaries and a l,2n0-kilowatt battery (one-hour rate of discharge) furnish current to the northwest part of the downtown district. Part of the output is also passed under the river, by tunnel, to the West Side. The high-tension switching installation is located in an air chamber in the roomy basement, which is also reserved for blowers, and cable connection to the old, previously described Wasliington Street Station. On a gallery above the main floor and directly over 52 T h c Chicago MARKET STREET SUBSTATION BriLDING Electrical Ha n db oo k 53 the rotary and feeder panel, a switchboard for the opera- tion of the 4,5()0-kilowatt auxihary steam phxnt in the adjoining building has been installed. Provision has been made for increasing the capacity and present arrangement to four 1,000-kilowatt converter vmits, two of which will have additional transformer and regulator capacity to give a range of 240-360 volts at the commutator, permitting their use for the charging of batteries without the intervention of boosters. Jackson Boulevard Substation This station occupies space in the basement of the magnificent new Railway Exchange Building on Jackson Boulevard, in the southeastern part of the downtown district. Here we have headroom permitting installation of 1,000-kilowatt units, two of which are now being installed. The ultimate arrangement contemplates six 1,000-kilowatt rotary converters with all accessories. Two 500-kilowatt units have been in service for about nine months in a temporary location during the construc- tion of the building. The load conditions in the vicinity indicate that a rapid increase in the capacity of the substation will be necessary. The larger and more im- proved type of converter units with three-phase trans- formers lend themselves readily to the excellent arrange- ment of apparatus. A noteworthy feature of this installation is the provision for an air supply consisting of a large duct running under the floor of the basement and having its intake, whicii is provided with a filter, opening at the sidewalk. Haddock Place Substation This substation is installed in the e.xtreme north- easterly section of the downtown district, near com- mission houses and a large number of elevator power consumers. It is connected by a heavy tie line to the bus bars of the Randolph Street Substation, about 800 feet distant. Two 1,000-kilow^att batteries (one-hour rate of dis- charge) and a 100-kilowatt, three-unit booster set com- 54 T h e C h i c a g o prise the electrical equipment of this substation. The first of these two storage batteries is notable in that it was installed in record-breaking time, the entire installa- tion of battery, booster, switchboards and all under- ground connections in street ready for one-hour rate of discharge, covering a period of only 57 days, from the date on which expenditure was authorized and apparatus and material ordered. The battery proper was installed by the Electric Stor- age Battery Company of Philadelphia, and all other work by the company's own organization. SOUTH SIDE SUBSTATIONS The old South Side of Chicago, known to the company as District No. 2, is bounded on the north by r2th street, on the east by Lake Michigan, on the south by 39th street and on the west by Armour avenue. Three substations supply this district with current for business and resi- dence purposes. Their locations are such as to form the electrical vertebrae of this rather attenuated branch of the .system. The maximum load in this district occurs somewhat later in the evening than that of District 1 and is, therefore, no additional strain on the machinery at the generating stations, upon which these substations are dependent, at the time of "Peak." State Street Substation Located just south of the northern boundary of Dis- trict No. 2 on State street, near 12th street, is the State Street Substation. Need for a substation in this locality was felt long before a location could be secured, for selec- tion of a .site was confined to a small radius. The im- mediate vicinity of the substation is developing rapidly with a class of commercial buildings requiring a consid- erable amount of general power as well as elevator power and lighting. This substation is notable in that it was erected on a 20-foot lot, which is rather narrow for substation pur- poses. However, the substation is a complete one, con- E I ecf r i cal H cnidboo Ic 55 taining two 500-kilo\vatt rotary converters, one 276- kilowatt battery (one-hour rate of discharge), with a 30- kilowatt, 3-unit booster set, capable of use as a balancing set. The high-tension apparatus is located on a gallery in the front over the rotary room, the battery being located in the basement. Living rooms for the operator are provided above the rotary room. The building, though rather small, is made conspicuous by the striking contrast which its neat pressed brick front presents to the somewhat sordid surroundings. It is entirely of brick and steel construction, and is altogether a very attractive and interesting little substation. Twenty-Fust Street Substation Located about midway between the State Street Substation and the Twenty-seventh Street Substation is the Twenty-first Street Substation. This plant is in- stalled on the site of an old generating plant, one part of the building being used as a storeroom, another as a substation. The load in this district is mixed business and residence lighting in its character. The substation contains two 500-kilowatt and one 250-kilowatt rotary converter, and is capable of exten- sion consideral^ly beyond this capacity, as a large amount of additional floor space is yet available in the old plant. Twenty-Seventh Street Substation Six years ago this plant was a generating center of the southern district of the Chicago Edison Company. It is located on Wabash avenue and 27th street, and about 2 J miles distant from Harrison Street Station. Being in a residence district and without railway or river facilities, all coal has to be hauled by wagons. The engines are run non-condensing. The building is of brick and contains, at the front, living rooms for the engineer and a lamp exchange room for the district. In 1898 rotary converters began to creep in and fires began to be banked. The little central station became a 56 2' h e C h i c a go dependency upon the Harrison Street Station. There remains, however, a generating plant of about 920- kilowatts capacity. Four Heine boilers, with a total of 1,700 horse-power, furnish steam for one 135-horse-power tandem compound and two 250-horse-power tandem compound Mcintosh and Seymour engines, and one vertical, cross-compound, 600-horse-power Ball & Wood engine. Belted to the first three mentioned are six 100- kilowatt Edison bi-polar shunt machines and to the last mentioned two 200-kilowatt General Electric multi- polar, direct-current, 140-volt generators. One gener- ator in each of these sets of two is connected on the posi- tive and the other on the negative side of the three-wire system. This station, which has been in operation for 12 years, still does regular duty as a subsidiary steam plant. In the same building with the generating plant, and in reality in the engine room of the station, there are two 200-kilowatt and one 250-kilowatt rotary, also a 30- kilowatt, 3-unit booster set. At the nortli side of the station a 275-kilowatt battery occupies a separate room. The rotaries are all of the older type, as this was the first rotary converter installation of the Chicago Edison Company, they being started in ser^•ice when the trans- mission line pressure was but 2,250 and later 4,500 volts. Some of these machines have been installed for six years, having been in continuous service during that time. In this substation were installed the first rotary converters ordered for lighting service in America. NORTH SIDE SUBSTATIONS In the northern district of the City of Chicago, a terri- tory of about two and one-half square miles, bounded on the north by North avenue, on the east by Lake Mich- igan, on the south and west l)y the Chicago river, are four substations. The load in the eastern portion of this district is principally a lighting load, but in the western and particularly southwestern portion a heavy El ccfr i c (I I n a n d h o o k 57 motor load is Ix'iiifi developed. Siibinarine cables afford a tie between the direct eurreiit network of this distrit-t and that of District No. 1, just south of the river. North Clark Street Substation On the north side of the city the Edison Company has one sul)sidiary steam plant, formerly known as the "Newberry Lil)rary Plant," a name derived from its proximity to the above-named building. The prox- imity in location is, in fact, almost identity, for the sta- tion appears to be a part of the same structure. This plant is rather small, but deceptive in appearance, for it is quite well filled with apparatus, there being both gen- erators and rotary converters installed. In its history and present capacity it is very much like the Twenty-seventh Street Station, previously described. Twehe hundred and seventy-five horse- power in Heine boilers supply four vertical, cross-com- pound Lake Erie engines, one of one hundred and fifty horse-power and three of two hundred and twenty-five horse-power each. To these engines are coupled two 50-kilowatt, 135-volt, direct-current generators and six 75-kilowatt, 135-volt, direct-current generators. These generators are balanced on the two sides of the three- wire system and are employed in their present capa- city as "Peak" machinery. This is one of the few substations where there are to be found remnants of the original rotary converter in- stallation, the company's first venture in converting apparatus and high-tension transmission. Two 100- kilowatt, 125-volt rotaries, one operating on each side of the three-wire system, also operating in parallel with the 250-volt, 500-kilowatt rotary, complete the substation equipment. Sedgwick Street Substation On Sedgwick street, near North avenue, the northern Ijoundary of the Edison Territory, there was erected about two years ago one of the company's typical mod- 58 The C hica g o ern substations — two buildings of fireproof construction, oile in the rear of the lot, being a separate battery struc- ture, while facing the street is the rotary converter building. This substation contains two 500-kilowatt rotaries at present, and a 425-kilowatt battery. A 30- kilowatt, 3-unit booster set furnishes a means of charging the battery from the system. In this station we find a high-tension gallery with the rotaries on the main floor. This type of substation is installed quite extensively by the company where build- ing lots are of inconsiderable width. The installation of the battery in a separate building leaves the basement of the rotary converter building free for the installation of air ducts and cable runs. Kinzie Street Substation The Northwestern Railway Company requires a large and unfailing source of electrical energy for operating air compressors which furnish compressed air for its signal system, as well as for lighting its passenger depot and terminal equipment and yards. For this purpose the Chicago Edison Company has installed in one of the Railway Company's buildings on Kinzie street one 250- kilowatt and two 100-kilowatt rotaries of the older type. In addition to furnishing direct current for the air com- pressor motors and railway company's lighting, three feeders from this substation supply the Edison System in the vicinity. Ohio Street Substation This substation represents all that is modern in the development of sul)station construction. The building is of brick and steel, equipped with a crane, and the basement free for vise as an air chamber and for cable runs. The second floor is occupied by a 600-kilowatt battery, while the main floor is planned for five 1,000- kilowatt rotaries, to be installed as the district develops. The present equipment consists of a 500-kilowatt rotarv converter and a 30-kilowatt, 3-unit booster set. Electrical Handbook 59 This substation also represents another piiase in the development of the company's property', in tliat real estate of continually enhancing value is secured while still within reasonable cost, and a commercial building of such nature is erected on rear of lot as will fulfill pres- ent requirements, permit extension to front, and such additional stories, up to eight in height, as future rental requirements may make advisable. Illinois Street Substation This little substation was installed in this particular part of the district only after it was found that it was impracticable to maintain pressure here by feeders from existing stations. The building, a small brick structure on an alley, is located on a strip of land which permits of enlargement and more permanent structure should the necessity arise. The present equipment is two 100-kilowatt, 125-volt rotaries, operating on either side of the three-wire system, and one 500-kilowatt, 250-volt rotary installation. WEST SIDE SUBST.\TIONS The West Side, known officially as District No. 3, is the newest territory invaded by the Chicago Edison Company. Five years ago there was practically no business in this section of the city and to-day five substa- tions are kept busy supplying the electrical needs of the district. This district, bomided on the north by North avenue, on the east by the Chicago river, on the south by 39th Street and on the west by Ashland avenue, covers an area of about four square miles, the Chicago river separating it from Districts 1, 2, and 4. Harrison Street Substation, which has already been referred to in the description of the generating station of the same name, due to its location on the north side of the plant, consists simply of two large batteries, each of 1 ,000-kilowatt capacity, at the one-hour rate. Its only piece of rotating macliinery, a 100-kilowatt booster, enaliles its batteries to l)e cliarged. 60 T he C h i cago The rather distant location of tliis battery from the load centers of either District 1 or District 3 renders it serviceable for either district, and therefore it seemingly partakes more of tlie nature of a station reserve than a district battery. Similarly the Market Street Substation, although located on the east side of the river and therefore in the downtown district, also supplies current to the three- wire system on the West Side. Lydia Street Substation Al)Out two years ago one rotary converter was hastily installed on the rear of a lot facing Lake street and ex- tending through to Lydia street, near L'nion street. The load increased at such a rate that work on a large substa- tion was soon begun. The present Lydia Street Sub- station, the result, is in some respects like the Market Street Substation, being located on expensive real estate. The foundation provides for a future seven-story build- ing of brick and steel, with cut stone and plate glass front, only two floors of which have so far been built. The future upper floors, when erected, may be rented to outside tenants, since the basement and first floors only are occupied by the substation. In the basement there is a storage battery witli a capacity of 1,000 kilowatts, on the first floor are two 1,000-kilowatt rotaries and above on a gallery is the high-tension eciuipnient of line switches and buses, from which leads are taken directly to the converter transform- ers on the first floor. A 100-kilowatt, 3-unit booster set, capable of use as a balancing set, on the three-wire system, completes the electrical equipment of this substation, which has come to be recognized as a most important one and bears much the same relation to District 3 as the Randolph Street Substation does to District 1. West Division Street Substation This substation, an exterior view of wliich is shown on page 61, is located on West Division street near Ashland E led r I c a I II a n d h o o k (51 avenue and is within onc-iialf mile of tlie nortlivvestern operating limit of tiie Edison Company; it hears the distinction of being the only coml)ination station of the company, that is, a sul)station distrilmting both direct current and 60-cyclc alternating current. The building is of l)rick and steel, witli a basement battery and a high- WEST DIVISION STREpyr SUBSTATION tension gallery above the rotary converter room. Living rooms for the operator are provided on the upper floor of the substation, and the front of the lower floor is used partly as a district supply office. This structvire is of rather greater width than the average substation, being 50 feet wide and making a double equipment possible. Two 500-kilowatt motor generator sets, supplied with 62 The Chicago 25-cycle current, deliver 60-cycle alternating current to portions of the northern and of the western districts of the Commonwealth Electric Company. Two rotary con- verters, a 425-kilowatt battery and a 30-kilowatt, 3-unit booster set are at present also in operation here. Both rotary and motor generators are fed from common trans- mission lines. West Fourteenth Street Substation This suljstation was installed in a new brick and steel structure on 14th street near John street about three years ago. It supplies the southern part of District 3. The building faces the street and is of sufficient size to accommodate three 500-kilowatt rotary converter sets. Future extension to a capacity twice this amount is possible. At present this station contains one 500-kilowatt rotary converter, one 2.50-kilowatt rotary and one 275-kilowatt battery with two 15-kiIowatt Ijooster sets, an equipment ample for the present needs of this district. LOW TENSION DISTRIBUTION SYSTEM In view of the fact that the low-tension distriliution system of a large Central Station Company, especially where conditions obtain which necessitate its position under ground, represents a large investment and that on its proper installation and operation the success of the company depends, a general description will be given here. Inasmuch as the part consisting of rotaries, storage batteries and their necessary accessories, switch- boards, bus bars, etc., have already been described under the substation headings, the underground portion onh' will receive our attention. Formerly the "Edison Tube," an iron pipe containing three conductors, was laid directly in the ground for use as feeders from station bus bars to the junction boxes in street and also for mains Ijetween these junction boxes. The junction boxes were circular, cast-iron shells, with three copper rings, positive, negative and neutral, on the interior, to wliich tlie copper of the tubes Electrical Handbook 63 connected. But that sj^steni has been very largely superseded. Instead we have a conduit and cable sys- tem, with roomy manholes at the street corners and junction boxes installed within the manholes. Glazed tile conduit lines, consisting of ducts from 4 to 24 in number, enclose the cables from manhole to manhole or to substations, as the case may be. Between the man- holes, where services enter the customers' buildings, REPRESENTATIVE CONDUITS AND MANHOLE, SHOWI.N'O I.SOLATION OF CABLES handholes are provided for a lateral connection of tile or iron pipe. Most of the cable in this system at present is single conductor paper and lead covered, varying in size from 250,000 c. m. to 2,000,000 c. m. A large amount of 1,000,000 c. m. concentric cable for feeders is now being installed on account of the better economy in duct space. Cables are carefully trained through manholes to avoid crossing, and great care is taken in providing against commimication of trouble from one cable to another. 64 T h c Chicago The cables are usually laid in ducts on the side walls of the manholes and covered with split tile. In cases where the use of this protection is impossible an asbestos cover- ing, held in place with steel tape, is provided. Page 63 shows the usual manhole and conduit construction. The manholes are usually constructed of brick and concrete, and vary in size from the so-called "handhole," about 2x3x3 feet, to the large manholes at street TU.NXEL roNSTRUCTlON .VXD CABI.E PROTECTIOX intersections, a common size being 6x8x6 feet. Ven- tilated iron covers are put on the concrete tops, and sewer drains are provided in the l)ottom. These manholes assume somewhat irregular shapes in some cases, for it is often found that on account of obstructions in the street the company has to utilize whatever space is left under ground. At the river crossings provided recently, of which there Electrical Handbook 65 are quite a number, the company has installed tunnels. These tunnels, usually of elliptical cross section, having a bore of about five feet, with the major axis liorizontal, are constructed of concrete and sunk to a depth wliich eliminates possibilities of entrance of foreign bodies, such as piles, etc. Page 64 shows tunnel construction. One of the oldest tunnels carries the "Trvmk Line" from Harrison Street Station to Adams Street Substation, and it has done duty for twelve years, despite the damage done by an occasional pile driven through its roof. This tunnel is about 65 feet below grade, while later tunnels are svmk to a depth of 85 feet and through the l)ed rock under the river. The substations and feeders are well disposed through- out the network and the objective "constant potential" is rigidly maintained. Pressure wires run back from certain junction boxes to the operator in a particular substation, indicating to him any departure from the "standard pressure" that he is required to preserve. The potential of 117 volts on each side of the three-wire system is maintained at the feeder end junction boxes, thus producing a pressure of 113 volts at the lamps. The earlier mains l)etween junction boxes were of vary- ing sizes, depending upon the density of the load con- nected. In the more recent installations these mains have been limited to a few standard sizes, the three con- ductors in any one main being always the same cross section. Cables of 200,000 c. m. and 350,000 c. m. for this purpose predominate very largely. In the earlier developments of the company, with com- paratively few feeders supplying a large area, the size of the mains was largely fixed by the drop in potential between junction box and customers' ser^•ice. The very great increase in density of load over given areas and the resultant necessary increase in number of feeders lias changed this consideration so that the sizes of mains are now very often fixed by the carrying capacity required. This makes it possible to have a much higher average current density in all mains. Tlie usual development, 66 The Chicago therefore, is simply to connect up additional feeders to the existing network of mains. Similarly, when the density of load in any particular locality increases beyond the point where it is no longer economical to carry it by means of feeders from existing stations or substations, a new substation is installed and the existing S3'^stem of feeders connected thereto. In this manner a feeder from an existing station is often rearranged to perform the functions of three feeders: namely, a shortened feeder from the existing station and two feeders running in opposite directions from the new sul)station establislied. Such a feeder is sometimes also utilized as a tie line between the old and the new sub- stations. In brief, therefore, the carrying capacity of the network of mains is reinforced by the installation of additional feeders, and the carrying capacity of copper in feeders is reinforced by the installation of additional sub- stations. An idea of the immensity of this system may be conveyed by the fact that there are 124 miles of low- tension mains and 69 miles of feeders supplyhig the Edison customers. Incandescent lamps, having an efficiency of 3.1 watts per candle power, are used for all except the lamps of 10 candle-power or less. The losses at 113 volts in incandescent lamps, arc lamps and meters are con- siderably less than those on systems using 250-volt incandescent lamps. The stability of this system has been put to severe tests in some instances, but the storage batteries and the inter- connected network have for several years operated very effectively against a total incapacitating of the system, a condition so dreaded by all central station companies. Conniioinvealth Electric Company The Coninionwealth Electric Company has three sources of electrical energy: the Fisk Street Station, pre- eminent with a capacity of 18,000 kilowatts; the 56th Street Station, a 3,0C0-kilowatt, 60-cycle generating plant, built four years ago, and a subsidiary steam plant, the Lake View Station. Besides supplying its own six substations, it furnishes current to the Chicago Edison Company and also to the Chicago & Oak Park Elevated Railway. The transmission is effected in a 9,000-volt, 3-phase, 25-cycle sj^stem, while the distribution is a 3-phase, 4-wire, 2300/4000-volt, 60-cycle, overhead sys- tem, which serves the more recently developed residential districts and suburbs of Chicago. In three of its substa- tions there are installed frequency changing sets of 4,500-kilowatt capacity, while the remainder are static transformer installations. While its own patronage of 11,000 customers, with a connected load of 728,000 incandescent lamps and 9,220 horse-power in motors, calls for about 6,500 kilowatts of generating capacity, the Chicago Edison Company demands the remainder for the supply of its numerous substations. The twofold aspect of the company is thus apparent — as generating a supply for the substa- tions of the Chicago Edison Company; as a generating and distributing agent supplying its own independent territory. FISK STREET STATION This station is located at the juncture of Fisk street and the South branch of the Chicago river, about three miles from the center of the downtown business district of Chicago. It stands nearly in the center of a plat of land of an area of fourteen acres, with a mean width of 67 08 T h c C h i ca (J o FISK STREET POWER HC)USE COMMONWEALTH ELECTRIC COMPANY Electrical H a ndb oo k G9 about six hundred feet, bounded on the south by the river. On either side of this phit of land a slip extend- ing north from the river about thirteen hundred feet provides an inexhaustible supply of circulating water for the huge condensers. The river furnishes an excel- lent coal conveying medium, and at the north end of the property a spur of the Chicago, Burlington & Quincy Rail- road facilitates bringing coal directly from the mines. The Fisk Street Station buildings, as at present constructed, consist of the boiler house, 190 x 165 feet, the turbine house, 225 x 65 feet, both of steel, and the separate switch house, 140 x 50 feet. These build- ings are designed for future extension to three and one- half times the present capacity. Of the French style of architecture, with red pressed brick walls and cut stone trimmings, they form a delightful contrast to the ordinary river front property. The unit idea pervading this whole plant makes itself evident at first sight. Every unit from the coal con- veyor to the last group of outgoing line switches is com- plete in itself, and the value of this idea in the localizing and confining of trouble will be at once apparent to the operator of large central stations. Page 68 shows a plan of the station. There are now installed three complete units, con- sisting of coal conveyors, boilers, Curtis turbo-gener- ators, steam and electrical auxiliaries and switching apparatus. The ultimate installation contemplates fourteen units. Each boiler unit consists of eight Balx'ock & Wilcox 512-horse-power boilers, equipped with automatic stokers and Meade conveyors. Coal is dumped directly from cars into hoppers in the basement of the train shed and from there conveyed to bunkers of 1,000 ton capacity above each unit of eight boilers. A steel stack 20 feet in diameter and 215 feet above the earth furnishes draught for each 2-boiler unit. In the yard there is also track capacity for 50 cars of coal of 35 tons each, and further dock space for 20,000 tons. A four and one-half foot 70 T h e C h ica go PLAN OF FISK STREET STATION E I ect r i ca I H (in d h o o k 71 72 T h e C h i ca g injection canal conveys circulating water from tiie east slip to each set of condensers, and an 8-foot discharge tunnel conveys the condenser discharge to tlie west slip. The 5,000-kilowatt turbo generators operate at 500 revolutions per minute at 180 pounds Ijoiler pressure with 150 degrees super-lieat, the potential being 9,000 volts delta with the neutral brought out and grounded. Regulation of the turbines is effected automatically by the operation of the governor, whicli opens or closes CROSS-SECTION OF SWITCH HOUSE, FISK STREET STATION individually 36 small valves, delivering steam to the nozzles. Essential to the successful operation of the.se turbines is an unfailing supply of oil for the step bearing of the shaft which carries the weight of the revolving field and steam bucket wheels, a total of 70 tons. Oil at about 1,000 pounds per square inch pressure niust be supplied constantly to keep the shaft off its l^earing, and to that end individual motor-driven oil pumps force oil at this Electrical Ha n d book 73 pressure into the hearing continuously while the turbine is in service. An "accumulator" or oil pressure reservoir operates in parallel with the pumps. In the turbine room, an interior view of wliich is sliown DETAIL VIEW OF TUKBINE on page 71, the steam auxiliaries are all located at the base of the Alberger surface condenser. They consist of a 140-horse-power horizontal Corliss engine, which drives the wet air and dry air pumps and the centrifugal pump, which is capable of supplying 140,000 cubic feet 74 T h e Chicago of water per hour to the condensers. Two separate steam-driven feed pumps supply the boilers with feed water, which is passed through a heater after leaving the hot well. All of these auxiliaries are within easy reach of the attendant, whose duties do not therefore require his presence in the boiler room. Operating control in this station is provided in the main turbine room on a specially constructed operating gallery of a capacity sufficient to control seven units. In addition, emergency operating tables and instrument panels are provided in the switch house. In the exciter system we have further illustration of the unit system of operation, as each turbo generator is provided with an induction motor exciter set (220-volt, 3-phase motor and 50-kilowatt, 125-volt generator). These sets are fed from the respective generators and are interconnected by common exciter busses. A battery operates in paral- lel with the motor-driven exciter units, and a 75-kilowatt steam-driven exciter is also available whenever occasion demands. A special electrical feature worthy of a more detailed description is the main operating switchboard on the operating gallery. This board is a combination of the instrument panel and the operating table. Complete equipments of indicating instruments for the generators and the outgoing lines occupy the instrument panel, while on the operating table portion are the controlling switches for oil switches, rheostats, etc. All control switch contacts are made on the under side of the table, the handles only projecting through the marble. A special synchronizing plug completes the closing circuit of the oil switch control switch, and causes on the syn- chronizer an indication of a synchronous or non-syn- chronous relation of the two points about to be connected by the closing of the oil switch. Special pilot lights with prismatic lenses furnish signals to the operator of the proper working of the remote control apparatus. On the rear of the board all the control and instrument multi-conductor cables end at a terminal board, carefully LtL|tlLllJljL|UL|lJljil|| s ' p s ' M, .^ , M, ^ ^: 6 6 6 O O O — 000O000G Diagram of High-Tension Connections— Fisk Strpt Station, Commonwealth Electric Company Electrical H andhoo k 75 lettered, and the wiring from that point to the control apparatus and instruments is a feature of the construc- tion. All cables leading from this board to the various points of control are lead-covered and are installed in individual iron pipes, which render communication of trouble to adjacent circuits impossible. On the turbine room floor each exciter has its switch- board with controlling devices, while at the turbine the operator is provided with a wattmeter indicating the total output of the turbine, a frequency indicator, and an electrical signal device which puts him in com- munication with the operator on the main operating switchboard. The high tension system is taken care of by carefully insulated open bus construction, with the buses of each unit in a separate chamber; all being separated from the oil switches on the floor above and the whole being histalled in the separate and especially constructed switch house, forty feet from the turbine house. The high-tension connections are best understood by refer- ence to the diagram of generator, bus and line connec- tions shown herewith. The output of the generator is conducted to the bus, in the switch house, in single- conductor, lead-covered, 600,000 cm. cables, drawn in vitrified clay tile ducts, oil circuit breakers of the most modern type being used throughout for high tension switching. No cable is used in the bus chamber; copper bars and rods insulated to withstand 20,000 volts have been used, these conductors being mounted on porcelain insulators. The outgoing lines, all three-conductor, lead- covered cables, convey the energy through an under- grovmd duct system to the various substations. One corner of the basement under the boiler room of Fisk Street Station is utilized as a substation. This is only a temporary arrangement, as it is intended later to construct a suitable substation building on the north end of the grounds surrounding the Fisk Street Station. At present this substation contains one 500-kilowatt rotary converter and one 250-kilowatt motor generator 76 The C h i c a g o set composed of a D. C. 250-volt motor and a three-phase, 4,000-volt, 60-cycle generator mounted on a common shaft, this machinery being entirely reversible in its operation. The principal output of this substation is a direct current supply to District No. 3 of the Edison Company, although four 60-cycle circuits are carried by this plant, for a period during the evening. FIFTY-SIXTH STREET STATION Situated just west of the Chicago & Eastern Illinois tracks is the 56th Street polyphase generating plant of the Commonwealth Electric Company. Page 77 shows an exterior view of this station. This plant is a notable one in many ways; for example, its location near a fashionable boulevard in the heart of a residence district. Its history as a pioneer in the three-phase, four-wire generating service, and its unique engineer- ing features, combine to make it, although installed five years ago, a most interesting central station. The station building proper, 112x120 feet, is an attractive one in appearance. The style of architecture of the building is such that none of its beauty is lost in the attainment of structural solidity. The boiler rooin, about 46x110 feet, contains six 400-horse-power Babcock 'fj— ^jg. TERMINAL ROOM Electrical Handbook 117 lished to fit the pefuliar requirements of a large and busy manufacturiufi; establishment in Chicago. To-day there are more than 1 ,200 private branch exchange switch- boards in business places, one establishment requiring the service of thirteen trained operators to handle its business. Electric lights as signals on telephone lines were first used in Chicago, and the development which has led to their general introduction in all large exchanges was started by their use in several of the Chicago Ex- change offices. The so-called automatic ringing was first used in a downtown Chicago office and has since been generally used throughout the country where inter-office ir unking is necessary. The general introduction of underground conduits began in Chicago in 1890, and has continued steadily each year until at the present time the Company is operating 235.36 miles of underground condviit, com- prising 1,372.28 miles of duct. The wire in under- ground cables at this time aggregates 149,233.68 miles, and of aerial wires in the Chicago Exchange 40,480.05 miles. In the downtown district the telephone wires operated by the Company are buried throughout. Cables are led from the exchange offices through the under- ground condviits and directly to the buildings or par- ticular business blocks to be reached. In the large buildings, direct cable terminals are established in base- ment rooms near the elevator or wire shafts which have been provided. Distribution is made by lead-covered cable to terminal boxes on each floor of the building and thence by individual wire led in behind moldings extended throughout the halls, so that in this way any particular office or room may be reached, the wiring being concealed throughout its entire length. Behind these moldings and in the underground runs, low tension wires only are provided for, it being arranged that elec- tric lighting, power or other high tension wires are sep- arated from them at all points. The standard of 200 pairs for underground cables was adopted in 1893, which has since been increased to 300 pairs and 400 pairs for 118 The C h i c a a o TYPICAL POWER PLANT OPKRATORS AT LUNCHEON Electrical Handbook 119 certain portions of the business district, all insulation being of paper encased with the usual lead cover. In the outlying districts the distribution of wires to the premises of subscribers is accomplished by means of pole lines, built in alleys. Undergrovmd cables are led directly to terminal boxes located upon poles in such lines, distribution being made by overhead wire for a distance of one or two blocks in either direction, so-called TYPICAL SUB-EXCHANGE BUILDING "drop wires" extending from these poles to the rear of the residence or place of business to be reached. There are very few pole lines located in the streets. The territory of the Chicago Exchange being about eighteen miles long by six miles wide, many long lines in the out- lying portions were inevitably involved. This territory is now covered by fourteen sub-exchange districts. In 1894, a four-party line service was introduced for the accommodation of private residences, a system of 120 The Chicago non-interfering signaling being provided which has con- tinued to meet successfully all requirements in this respect. By ordinance requirements in 1889 the rates for service in tlie Chicago Exchange were based on an annual sum for which the sub- scriber might use the telephone to any extent de- sired. Later on the requirements of very heavy users necessitated private branch ex- change systems, and the require- ments of private residences were such that one cir- cuit might readily accommodate a number of sub- scribers, which m a d e variations in this plan inevi- table. The injus- tice of this so- called flat rate plan continued to be more and more apparent. The very small busi- ness user under it must of necessity pay just as much as the greatest. The storekeeper who used his telephone five times a day paid just as much as one whose use might be fifty or more calls. Measured rates were introduced in 1896, and immediately these were adopted to a large extent. It was not, however. Electrical II a n dbook 121 until 1900, when the measured service plan was intro- duced upon what is known as tlie "nickel" basis, that the Chicago Exchange took on a tremendous growth, which has since continued. Upon this plan the user of the tele- phone pays for the service at the time it is rendered, depositing a nickel or 5c piece in the coin box provided for that purpose. Upon tliis plan service is furni.slied, not only upon direct lines but in private exchanges, two- party and four-party lines, and also, for very small users, upon ten-party lines. In tlie latter class the telephone is installed in a residence upon a guarantee by the sub- scriber tliat the earnings shall not be less than 5c per 5UB-EXCHANGE 1XTF:RI0R day or in a place of business 10c per day. Nearly 50,000 telephones are now operated in Chicago on the nickel plan, and it is used by all classes of customers. The ten-party lines are separated from the general body of exchange lines and operated on special switchboards so that they may not in any way delay the general service of the exchange, other classes of service being operated in the usual manner, the type of coin box making it possible to accomplisli this without retarding the service. Twelve of tlie fourteen Cliicago Excliange offices are operated in buildings owned l)y the Company, the two remaining lieing pro^•ided for by perpetual leasehold in 122 The Chicago fireproof office buildings. Relay multiple switchboards, accompanied by the usual storage battery and power plants, are operated in all of the offices, the system of trunking for intercommunication comprising a total of 3,658 trunks or junction circuits. In the territory outside of the Chicago Exchange the Company owns eleven buildings in which its switch- boards are operated. The annual statistics for the past ten years, showing r l^R-P^"^' kss*^ ^^^■P**^^ .Jr i- ^^^ MAIN OFFICE INTERIOR in a general way the growth of the Company's business, are indicated in the following table. The entire plant of the Chicago Company, including cables, switchboards and instruments, is now of the most modern class. Its efficiency is attested in the very large amount of traffic successfully handled. The engineering plans of the Company are based on an ultimate capacity for 250,000 telephones, and the widespread and increasing use of the service makes it appear not unlikely that this number may be reached even earlier than has been antic- pated. o o w 12; CO o P^ H O o < a o o O o o o w PQ r5 CI f -t" 00 ' 1 1 ° 00 ■» cc t~ CO 00 X OS C«5 "^^ 'M co_ M •* f O os' — ' ^" i § O -i< -r -r CO i '^ 1 "^ i 1 1-H IM C<3 CO t^ IM 00 M ! tH 1 05 't 05 05 r~ f ! CI e>i O — t-- iO_ t^ o 05 O)" ^ co" oj" 00' >o -1 o CO_ OS_ ^ 1 "^ a> co" .^ t~-" lO" (N 10 q^ '-' iC X CI CO -r 05" •* -J Tf ^ •* CO ■* « "5 s § q o o 30 O rH (M t- OS 05 -^ .-H Tf rH co" 00 U5 r-H_ 00 00" os" C) CO '"' CO CO rt 05 05 -1 CO_ ^ lO f- tT CO X 00 t^ r^ ■*" 00 ■* q '"' M Tf rt rt t'- >o 00 CO CO -^ h- OS "O OS co 00 lO 00 '00 CD CO lO C^I w ^- 7-1 M CI CO i <-H ^ 00 ^ ^' lO h- CO CO '-' c^ CO — 1 r-i >o ^" N (M 05 00 ■* ^ ^ (N "I 05 -* 00 O ''■5 CO CI CD CO CI 05 01 C0_ 00 OS '— ' 00 to' -t" r-." CO CO CO CO '^ Cl -H -4" TfT ^ « •* •* lO X 05 CO 1 to 'X! 05 CO CO CO 00 "O t^" CI C co' " CI -H ^ co_ (N (M 05 !N -H tV OC s co" OS lo (N t» CO >o t- "5 OS o — 05 05 c awrcMice avenue. The water to How througli tiiis channel must he suppHeu ))y pumping, and a plant having a capacity of 60, 000 cubic feet per minute will be erected near the lake and operated 1)}' tiie Sanitary District. When completed thi.s cliannel will become the outlet of sewers. Surveys for the purpose of locating the channel liave I)een made. The typograpliy and' hydrography of tlie Calumet District admit of treatment that will secure a reversal of the current of the Calumet river and a gravity flow therefrom into the main channel of the Saiutary District through the depression known as the Sag Valley. Sur- veys have been made and a channel partially located, which will accomplish the purpose outlined above. The tentative plans for this channel contemplate tliat its cross section shall be 70 feet wide at the bottom in the earth and 90 feet wide in the rock, with side slopes in the earth of five feet in three feet and a deptli below hydrau- lic grade line of 22 feet. The work of the Sanitary District has created valuable possibilities in the way of water-power development, and the same Legislature which passed the annexation laws enacted a law which enables the Sanitary District to realize in part these possibilities by giving it the authority to de\'elop the water pow'er at Lockport. This work is now under contract, and construction is in progress. The plans for it provide for an extension of the channel now in use between concrete walls and earth and rock emliankment southward for a distance of about 10,700 feet to tlie site selected for the erection of the power plant. From this point on, a tail race is to be excavated for a distance of about 6,800 feet to a junction with original Section 17; this tail race is to be 160 feet wide, and be deep enough to afford a minimum depth of water of 22 feet. Section 17 is a wide channel, and the minimum depth of water therein, until it enters the Upper Basin at Joliet, will be ten feet. The mean head for power development resulting from this improvement will be 32 feet, and tiie net horse-power, figured on an Electrical II a ii d b o o k 15 1 efficiency of 75 per cent aiui a fiow of (30(),()()0 cubic feet per minute, will be 27,000 hor.se-power. The power is to be housed in a structure of concrete and brick con- struction and will have ten turbine chambers, three for exciter units and seven for power luiits. The power units are designed to pass 100,000 cul:)ic feet at 8-10 dis- charge. They consist of turbines on horizontal axes, capable of generating 6,500 horse-power at full gate under 34 feet of head at 150 revolutions per minute. Each power unit is to drive one 3,750-kilowatt, 3-phase, 2,200-volt generator. The ultimate discliarge of the channel will, under present plans, reach 800,000 cubic feet per minute. This outline of tlie work shows that its primary pur- pose is sanitation, and that in attaining that vital object it provides an artificial waterway of great utility and develops water power of inimcn.se value. Sanitation, navigation, and industrial development are the visible results of the vast expenditure made l)y tlie Sanitary Di.strict of Chicago. MAIN CHANNEL The Main Drainage Channel of tlie Sanitary District of Chicago is now completed from its confluence with the ?outli branch of the Chicago river, at Robey street, in the city of Chicago, to Lockport, in Will County, Illinois, a distance of 28.05 miles, as shown upon the accompanying map. Water from Lake Michigan was let into the main channel via the Chicago river, and through the auxiliary cliannel which connects the main channel with the west Fork of tlie south branch, on January 2, 1900. It took thirteen days to fill the channel from Western avenue to the Controlling Works. On the morning of the 17th of January, 1900, by permission of the Governor of tlie State of Illinois, the Bear Trap Dam was lowered and the w-estw'ard flow of water from the lake was com- menced. At the end of Section 15 of the channel the Controlling Works are located. Beyond tlie.se works the construction completed by the District covered the 15^2 T It c C h i c a g o Electrical H a ii d b o o k I .>.S work necessary for coiHluctiii';' tlic How from (lie cliaiiiu'l in conjvniction with tlic waters of the Desphiines river down the declivity to and througli the city of Joliet, and the making of such changes in the Illinois and Michigan Canal as \\\o now coiulitions developed rendered necessary. The first work pvit uiuler contract extended south- westerly from the Willow Springs road, and these sec- tions were numbered consecutively Numbers 1 to 14. Average length of sections, nearly one mile. Easterly from Willow Springs road tlie sections are lettered from A to O, omitting J. The lettered sections are, except for a short distance near Summit, entirely in glacial drift, defined in the specifications thus: "Glacial drift sliall comprise the top soil, eartii, muck, sand, gravel, clay, hard pan, boulders, fragmentary rock displaced from its original bed and any other material that overlies tlie bed rock. " The sections from 1 to 14 were put under contract in July, 1892; those from A to F were put under contract late in 1892 and early in 1893; and those from G to M, inclusive, were contracted for in December, 1893. Sec- tions N and O were put under contract May 2d, and Section 15, August 27th, 1,S94. Earth was first broken on "Shovel Day," Septeml)cr 3, 1892, on the rock cut below Lemont. The Desplaines Valley is traversed by the river from which it takes its name — a stream of wide fluctuations, with no constant and reliable fountain supply. During some seasons its whole discharge would pass through a six-inch pipe, and at otliers its volume reaches 800,000 cubic feet per minute. Then it rolls majestically along, flooding the whole valley. Sucli being the situation, control of this stream was a condition precedent to the successful prosecution of the work upon tiie main channel. This control has been secured by the outlay of $1,000,186 (exclusive of bridges) in constructing what is known as the "River Diversion Channel." About thirteen miles of new river channel liad to bg 154 The Chicago E I e c t r i <■ (I I II (t II d b o o k 1 55 excavated, paralU'l witli the location of the main uraiiiage channel, and about nineteen inilefs of levee built to di- vorce the waters of the Desplaines watershed from the ciianncl whicli is to receive the waters of Lake Michigan and pass them on to tlie Mississippi river via the lower Desplaines and tlie Ilhnois rivers. The width of the River Diversion Channel on the bottom is 200 feet, side slopes one and one-lialf to one, grade generally 12-100 per 1,000 feet. At the head of this River Diversion it was necessary to provide a safety valve in the form of a spillway, to allow surplus water to flow toward Chicago, pending the completion of the work necessary for carrying the entire flood waters of the Desplaines through Joliet. This spillway is a concrete dam capped with cut stone, and its wings faced with stone masonry; it is 397 feet long and its crest is 16.25 feet above Chicago datum (this datum is referred to the low water of Lake Michigan of 1S47, and is 579.61 feet above sea level at Sandy Hook). No water flows over this spillway until the water passing the water gauge above it reaches 300,000 cul)ic feet per miinute. The cross-secton of tlie earth sections from A to E inclusive, a distance of 5.3 miles, is 202 feet on the bot- tom, side slopes two to one. This .section extends for about 500 feet into the west end of F and then reduces to 110 feet on the bottom, preserving the same side slopes for a distance of 7.S miles. The explanation for this change of cro.ss-section is as follows: Throughout the rock sections, and those sections in which there is a preponderant e of hard material, or where rock may appear, the section adopted is designed according to law for a flow of 600,000 cubic feet of water per minute, which means provision for a population of 3,000,000 people. The narrower channel provides for the flow of 300,000 cubic feet per minute, or for al)Out the present population of Chicago. The enlargement of tlie narrow channel can be made by the easier methods of excavation, such as dredging, whenever the needs of the city require 156 The Chicago it. The grade througliout tlie lettered sections is one foot in 40,000 (.025 per 1,000 feet) and the bottom of the Channel at Robey street is 24.448 feet below datum. The numbered sections, from \o. 1 to No. 6 inclusive, are underlaid with solid rock. The width of the bottom, in rock, is 160 feet, and walls of masonry laid in cement have been bviilt upon the rock surface to a height of five feet above datum. Sections 7 to 14, inclusive, are in solid rock, widtli at bottom 160 feet, sides vertical, prism taken out in three stopes with offsets of six inches on each side for each cut, making top width 162 feet; grade in rock, one foot in 20,000 (.05 per 1,000 feet). Section Xo. 15 is also in rock and its cross-section is enlarged at its south end so as to form a "windage basin," in which large vessels may be turned around. The Con- trolling Works are located on this section. The.se works consist of gates and a movable dam by which the flow of water from the main channel into the tail race, which is to deliver the outflow into the Desplaines river, can be controlled. This river below Lockport follows the trough of the valley down a steep declivity to the canal basin in Joliet. The fluctuations in Lake Michigan, by varying slope of water surface, will be felt at the controlling works, and provisions have been made to meet these fluctuations within a range of five feet above datum and twelve feet below, or an extreme oscillation of seventeen feet. The fall from datum at the Controlling Works to the level of the upper basin is about forty-two feet, in a distance of about four and one-third miles. The Controlling Works comprise seven sluice gates of metal, with the necessary masonr}' bulk heads and one bear-trap dam. The ^sluice gates maj' be considered as a modification of what is known as the Stoney gate type, gates having a vertical play of twenty feet and openings of thirty feet each. The bear-trap dam has an opening of 160 feet and an oscillation of seventeen feet vertically. This dam is essentiallv two erreat metal leaves hinged to- . \ - ' .•^ ' -■ f*^4y Electrical Handbook 157 gether and working Ijetween masonry bulk heads. The down-stream leaf is securely hinged to a ^'ery heavy foundation, and the up-stream leaf is so placed as to present the harrier to the water. This structure is oper- ated by admitting water through properly constructed conduits, controlled by valves, beneath the leaves just described. To raise the crest of the dam, water is admitted from the up-stream side and the discharge shut ofT until the desired height is obtained, and then the valves are adjusted so that the vohime of water beneath the leaves shall be constant. To lower the crest, the water beneath the leaves is drawn off until the desired heiglit is reached, when the valves are again arranged so as to maintain a constant volume of water. All the bridges on the main cliannel are movable structures. There are six bridges for public highways. One was built for the use of the Southwest Boulevard and Western avenue. It has double roadways — one being for heavy and the other for light traffic. There are seven railway bridges, one being an eight-track rolling lift structure, with a channel span of one hundred and twenty feet. One is a four-track swing bridge, and the others are double-track structures. The bridges on the walled and .«olid rock sections of the channel are all "bob-tailed" (or have arms of unequal length), counter-weighted structures, with pivot piers on the right bank, and long arms spanning the entire channel, thus avoiding any obstruction to the flow from center and protection piers. These bridges are of latest design, conforming to the heaviest modern specifications. The entire weight of the iron and steel used in tlieir construction was 22,862,- 454 pounds. The work of the District .'•outli of the Controlling Works consisted of straightening, widening and deepening the Desplaines river, to give it a flowage capacity of 1 ,500,000 cubic feet of water per minute. This involved, in the city of Joliet, the rebuilding of Dam No. 1, the removal of Dam No. 2 (both structures belonging to the Illinois and Michigan Canal), anil the removal of the 158 T h c C h i c a (j o Electrical II a n d b o o k 1 .59 Adam dam, tlie rebuilding of Lock No. 5, and the removal of the Guard Lock. At Jefferson .street, the stone-arched bridge has been removed to make way for a steel bridge of greater span and width, equal to that of the street. The Cass street bridge also gave place to a modern steel structure of greater span and width. From Lock No. 5 to Jefferson street a massive concrete wall has been constructed to separate the Illinois and Michigan Canal from the river, and on the east side of the river a concrete wall has been constructed, extending from Cass street to JefTerson street. At Jackson street a great deal of costly excavation has been made to admit of an extensive water power development, which is the property of the State. The total amount of excavation involved in the con- struction of the main channel is 26,693,000 cubic yards of glacial drift and 12,265,000 cubic yards of solid rock, or an aggregate of 38,958,000 cubic yards, to which must be added the material excavated from the River Diversion; glacial drift, 1,810,652 cubic yards; solid rock, 258,659 cubic yards; total River Diversion, 2,069,311. The work between Lockport and Joliet, including the Con- trolling Works, involves 1,201,724 cubic yards of excava- tion; grand total main channel. River Diversion and Joliet Project, 42,229,035 cul)ic yards. All of this work is now completed and in addition thereto 457,777 cubic yards of retaining wall and bridge masonry. The retain- ing wall is all laid in cement mortar. The rock when broken up expands about 80 per cent, and therefore the volume of the rock spoil banks will be nearly 22,542,586 cubic yards. The whole volume of spoil (earth and rock), if deposited in Lake Michigan in forty feet of water, would make an island one mile stjuare, with its surface twelve feet above the water line. In addition to these quan- tities the work of the main Cliannel extension and water power development involves 105,000 cul)ic yards of earth, 1,274,000 cubic yards of rock and 145,000 cubic yards of masonry and concrete. 160 The Chicago CHICAGO RIVER The distance from the mouth of the Chicago river to Robey street (the junction of the artificial channel of the Sanitary District of Chicago with the west fork of the south branch of the Chicago river) is six miles. From Lake street to Robey street the channel is to be widened to 200 feet and given a depth of 26 feet for a mid-channel width of 100 feet, shallowing up to 16 feet at the dock lines. The standard docks are of timber secured to anchor piles 38 feet back from the dock face. The Board of Trustees has authorized the construction of a concrete dock on the west side of the river, extending from Ran- dolph street to Madison street, and it is now in process of construction. Much work has been accomplished in executing the plans of the District for river improvement. Up to the 31st of December, 1903, 488,650 square feet of land has been acquired for widening, nearly all of which has been excavated liy dredging and the frontage docked. The dredging thus far aggregates 2,935,691 cubic yards and the docking 10,822 lineal feet. Seven bascule bridges have been completed, one of which is a double-track rail- way bridge of 275 feet span between points of support. Two others are now under contract and plans are author- ized and in process of preparation for four more. The bridge at Ashland avenue is a trunnion ba.scule, of a type invented by John W. Page; all of the others are of the Scherzer Rolling Lift type. DIMENSIONS AND COST OF CHANNEL The distance from the mouth of the Chicago river to the junction of the main channel with the west fork of the south branch at Robey street is about six miles. The length of the main channel proper, from Robey street to the Controlling Works at Lockport, is 28.05 miles — making a total of 34.05 miles. The dimensions of the channel are: Robey street to Summit, 7.8 miles; 110 feet wide at bottom; 198 feet at Elect r i c a I H a n d book 1 (i 1 water line, with miniinuni depth of water 22 feet. Sum- mit to Willow Springs, 5.3 miles; 202 feet wide at bottom, 290 feet wide at water line, with 22 feet deptli of water; grade of eartJi channel one foot in forty tiiousand feet, or If inches per mile. Tlie side slopes in eartii are one foot vertical to two feet horizontal. At Willow Springs the channel narrows to the walled and rock cross-section, extending 14.95 miles to Lockport, 160 feet wide at bottom, 162 feet at top; grade in rock one foot in twenty thousand, or 3^ inches per mile. The velocity in earth is figured for 1 \ miles per hour and in rock 1.9 miles per hour. For talile of costs, see page 162. METHODS OF WORKING On the earth sections some novelties were introduced. On sections L and M, cars, specially constructed, were loaded by steam shovels and drawn by steam lioists up a steep incline to a proper height, where they ran on to a tipple and were automatically dumped. Each incline was equipped with two four-yard cars, which loaded and dumped alternately. On sections I and K, the contract- ors erected bridges spanning the spoil bank at proper height, their supporting piers being carried on trucks which traveled on tracks parallel with tlie cliannel. From the channel end of the bridge, an inclined track ran down into the cut. In connection with this device two eight-yard cars were used, which were successively loaded by steam shovel, drawn up the incline on to the bridge by steam hoist, and then automatically dumped and immediately returned to the pit. An output of 100 j'ards per hour was probably sustained liy tliis combina- tion of devices. On Section H, a conveying machine, designed by Messrs. Hoover & Mason, was constructed on a mam- motli scale. It was essentially a bridge, spanning ihe channel, with cantilever arms projecting far enough beyond on each side to overhang the spoil area. On this structure were mounted the necessary sprocket wheels 162 The Chicago y 5 w Q < Oo pco o| < OOCCO OO_OC0 COt^M-t COO OICO 1 XI--C to dr.; 00 05 --Id 00 Tf o6« §3 dd oo ON o-*< co'co in 05 mV I n 1 CO CO_^N nV OS CO '^' 00 rt" 1 '^ r-'c-f - s« » m e© '§5 =c .a u «•, e > a> III gape Sii ri s£5 s§5 =^-c^ Ss-? --^^-r o£-? £^;x -Ikk g-c;:: O 10-.0 ooo ^.2 i. =:*^ E led r i c a I II a n d b u u k Wii and other machinery for carrying a series of steel pans which form tlie conveyor belt. The structure was 640 feet from end to end, mounted on trucks traveling upon tracks parallel witli the cliannel, and its capacity was 500 cubic yards per hour. This capacity, however, was that of the conveyor only; the arrangements for excavat- ing the earth and loading the conveyor were ne\er per- fected to an extent which secured recognition for the device as one of the successful inventions applicable to great public works. On Section F the material was taken from the steam shovel by cars fitted with pneu- matic dumping apparatus, the power for which was supplied from the loconiotive. The engineer operated these dumps just as he would apply the air brakes. Sections A, B and a portion of C are located in the old channel of the Desplaines river, and were overlaid with muck to a considerable depth. This muck was removed by hydraulic dredges. Each of these dredges has a capacity of about 2,500 cubic yards in ten hours, and this output in solid matter represents about eight per cent of the capacity of the pumps. One great advantage of the hydraulic method of remo\al is that the material can be removed to any desired dmnping ground within a distance of 3,000 feet without adding anything to the contract price of the excavation. On those sections which are partly in eartli and partly in rock, all of the usual methods of removing earth were employed, varied to suit peculiar conditions or to meet the ideas of the contractors doing the work. On section No. 6 a large amount of muck had to be removed, and a very ingenious contractor improvised a hydraulic dredge at a small cost, and did tlie work at a very moderate expense. On the rock sections the sides were cut down vertically by channeling machines, and the merits of several devices were satisfactorily demonstrated on this work. Of course, steam drills were used, and on tlie sections which were best planted these were worked from a central power station by compressed air. Tlie top lifts were removed bv the use of carts and tramcars, tlie traction for which Electrical II a n d I) o o k 1 (j.5 latter was usually supplied l)y .steaiii-lioisting engines. The lower lifts were taken out by the use of cal)le-ways, high power derricks and cantilever conveyors. The cable-ways as first constructed were not very successful, but experience gained upon this work resulted in improvements from time to time, until by the adoption of a simple improvement, devised by Mr. H. C. Locher, one of the contractors, they were brought to a stage of efficiency which made them worthy competitors of the cantilever conveyors. The high power derricks used upon two of the sections did not come up to the expecta- tions of the builders, and their use was confined to the machines already in place. The revolving derricks on Section 14, after a great deal of costly experimentation, developed considerable merit. The cantilevers are probably the most perfect devices now known for hoisting and disposing of material from rock cuttings such as these. The average daily output of rock for the month of June, 1895, reached 21,365 cubic yards, requiring the use of eight tons of dynamite. Although all of the bridges on this channel are movable structures, yet the law allows the District to keep them closed and operated as fixed structures for a period of seven years dating from January 17, 1900. At the expiration of that period they must be equipped with operating machinery and go into service as movable bridges, and then this channel will be a free water-way, navigable for any craft drawing less than twenty-two feet of water. The work performed by this District consti- tutes nearly two-thirds of the entire cost of creating a channel from Chicago to the Mississippi, which would be navigable for the largest boats which will be able to ply between St. Louis and New Orleans, after the present plans for the improvement of the Mississippi will have been completed. The creation of such a channel seems to be inevitable; a commercial necessity sooner or later to be recognized and undertaken by the general govern- ment, which must carry out the enterprise, if it is ever executed. SOME INTERESTING APPLICA- TIONS OF ELECTRICAL POWER Bndgcporf Piniipiiicr Station AN ELECTRIC PUMPING PLANT PROVIDING PART OF THE POWER TO DRIVE ITSELF The above pumping station is located in tlie south- western part of Chicago, on the south branch of the Chicago river, near Archer avenue. Its function is primarily to maintain a sufficient depth of water in tlie INTERIOR OF ECONOMY LIGHT AND I'OWKK PLANT AT JOLIET, ILLINOIS Illinois & Micliigan Canal for tlie operation of canal boats. The water is lifted from the river into the canal, a height varying from three to seven feet, according to the height of the river. Incidentally, also, this pumping station keeps the water in the soutli l^ranch of the Chicago 169 170 The Chicago river in circulation, thereby greatl}' improving tlie sanitary conditions. The pumping station consists of a long, narrow build- ing, through the length of which is the wheel pit, in which are located five impeller pumps manufactured at Connersville, Ind., each liaving a capacity of 7,000 cubic feet per minute when running at 70 revolutions per min- ute, and designed to pump at a head varying between three and seven feet. A line shaft extends the entire MOTOR AND CONNECTION, MAIN SHAFT OK BKlDGKi'OKT PUMPING PLANT length of the building, being in three sections, a short section at the center and two long sections extending in each direction to the end of the building. By means of friction clutches the three sections can be thrown together, or the center section can be operated in conjunction with either end section. To the outer end of each of the long sections is belted a General Elec- tric, 14-pole, 300-horse-power, 514-revolutions-per- minute, 2,080-volt, three-phase, 60-cycle induction motor. To each of tlie long sections of shafting are Electrical Ha n d b o o k 171 belted two of the pumps, and to the center section, one pump; the arrangement being such that the latter may be dri\en from either motor bj' properly manipu- lating the clutches above referred to. The power for operating the motors is received over a long-distance transmission line from tfhe Economy Light ct Power Company's plant, which is located on and receives power from the Drainage Canal, at Joliet, 111., thirtj'-five miles distant. The current is three phase , POWER HOUSE AND D.\M, ECONOMY LIGHT AND FOWEK COMPANY 60 cycle, and the line voltage 31,000. The three trans- mission wires enter the end of the building through suitable openings, and are tied to insulators on each side thereof, the lightning arresters being located on the wall of the building immediately below. The conduc- tors are led from the insulators into the primary windings of three water-cooled, 200-kilowatt, General Electric single-phase transformers, having primaries wound for 31,000 and 29,000 volts, and the secondaries for 2,300 volts. Reactance coils are placed between the trans- formers and the point at which the lightning arrester 172 The C h i c a 90 connections are made. The secondary conductors from the transformers are led to the motor panels, one for each motor. Each panel contains an automatic oil switch, voltmeter, ammeter, and the necessary current and potential transformers for these instruments. The motors are proxided with polar wound armatures INTERIOR OF BRIDGEPORT PUMPING PLANT and starting resistances mounted in the spiders of the rotors and are connected directly to the panels. Since the pumps are of a type having an initial suction and at times must be started against a head of as much as seven feet, and as no clutches are provided on the shafting to enable the motors to be started without load, it is necessary that the motors should start at least two of the pumps under full load, which they readily do, com- ing up to normal speed in something less than a minute. By reason of the starting resistance and the polar wind- ings of the rotors, they accomplish this without an K led r i c a I II a h d h o o k 1 7.'J abnormal rush of line current or appreciable drop in the line voltage. A novel feature about this installation is that the water which is pumped by it into the Illinois & Michigan Canal finds its way into the water wheels of the gen- erating plant at Joliet, thirty-five miles away, and is utilized in producing power for the operation of the pumps. In other words, the pumping plant provides part of the power to drive itself. It is estimated that the water utilized in this way, after deducting all losses (including the evaporation and seepage generator, line and motor losses) , is in the neighborhood of 200 horse-power of the 600 horse-power needed to do the pumping. Or, to put it in another way, the motors furnish 600 horse-power at their pulleys with an actual net consumption of approximately 400 horse-power. The cut on page 172 illustrates the interior of the pumping plant and shows the tops of the pumps, and at the farther end, one of the motors. The motor at the opposite end is shown in the cut on page 170. This cut aleo shows the three step-down transformers, the open- ings on the wall for bringing in the transmission wires, and just below the latter the lightning arresters. The Economy Light & Power Company's dam and power house, at Joliet, are shown in cut on page 171, and the interior of the power house, with one of the generators in the foreground, is illustrated on page 169. Packing; by Rlcctricity The packing industry of Clue-ago is conceded to be one of the most interesting and important commercial estab- Ushments in the world. The Stock Yards proper, cover- ing an area of a mile square, form an example of the scale upon which this business is conducted. The packing houses west of the Stock Yards cover an area of one-half mile liy one mile. Swift & Company occupy a portion of this area, their plant covering forty-seven acres of land, with a floor space of eighty-seven and three-quarter acres. The dif- ferent branches of the industry are here conducted on the most modern lines, approved for the quickest and best conversion of live animals to finished food products and their various by-product accessories. Cattle are slaughtered in their Chicago plant at a rate of 240 per hour, hogs 700 per hour and sheep 620 per hour. The refrigerating plant has a daily capacity equal to that furnished by 2,500 tons of ice. They employ 23,000 people, and their distributive sales for 1903 exceeded $200,000,000. At present, Ijesides several outlying steam-power plants, they have a central electrical generating station, which furnishes power to motors throughout the packing estab- lishment. The boiler house contains 6,400 horse-power hi Bab- cock k Wilcox boilers, delivering steam to the engines at 150 pounds pressure. These are equipped with Murphy stokers and with coal and ash handling machin- ery. The stack is built of brick and is 265 feet high. In the engine room are installed three General Elec- tric, three-phase revolving field, 24()-volt, 60-cycle 175 17C T h e Chicago generators. One of these generators, of 300 kilowatts capacity, is direct connected to a 13 x 26 x 48 Filer & Stowell cross compound Corliss engine; another, of 600 kilowatts capacity, is direct connected to a 19 x 38 x 42 engine of the same make, and a 1200-kilowatt generator to a 27 X 54 x 42 engine of the same make. All three units operate at a speed of 120 revolutions per minute. There are installed a total of about 3,600 hor.se-power in induction motors of the General Electric Squirrel Cage Motor type, and about twelve thousand 230-volt incandes- cent lamps, besides a large number of series alternating current arc lamps. The motors range in size from 1 to 140 horse-power, the average horse-power per motor being 14.37. Many of these motors are in odd and vmusual places, some in coolers at zero temperature, others in dusty, dr}' rooms at over 125 degrees temperature, and numerous and novel special constructions have neces- sarily been developed in connection with the motor in- stallation and wiring system. This plant offers a striking example ot the advantages possessed by induction motors, as the conditions in many parts of the plant are too severe to admit of the satis- factory and economical use of direct current motors. Little or no advantage is derived from the use of the multiphase system in respect to saving in conductors, as it will be noted that the voltage is low. There were originally several separate plants driving direct current generators furnishing lights and power, all of which were abandoned when the alternating current system was in- stalled. This radical and extensive change was long contemplated before being made and was the result of long and careful investigation and the previous installa- tion of a smaller multiphase plant in one of Swift & Company's other packing houses, which afforded an opportunity for actual and practical experience with both systems. A few synchronous motors are used which tend to help the power factor; one of these is a 100-kilowatt machine, driving pumps. luteruaiional Harvester Coiupauy Mccormick division This plant, devoted to the manufacture of complete harvesting machines, covers a large area, cut in half bv the Chicago river, at Blue Island and Western avenues. Electric power is distributed for all purposes, from the driving of shafting in the twine mill to the operation of cranes in the foundry. An interesting application of motors at the plant is the driving of a coal pulverizer by a 75-horse-power Westinghouse induction motor, and also a coal crusher by a 15-horse-power Westinghouse induction motor, using a Morse chain. Both alternating and direct current is used ; 550- kilowatt alternating current generating capacity in two units, three-phase, 7,200 alternations, 440 volts, one of which, a 300-kilowatt Westinghouse, is shown in the accompanying illustration. There is approximately 900- kilowatt direct current generating capacity in seven units, 250 volts, two motor-generator sets, one 200-kilo- watt and one 100-kilowatt, consisting of induction motors driving direct current generators. Another illustration shows a direct connected exciter unit at this plant. DEERING PLANT One of the largest of Chicago's great manufacturing institutions is that of the International Harvester Com- pany's Deering plant, which was founded by William Deering in December, 1880. The intervening period of less than twenty-four years, Avhich has witnessed the gigantic development of the electrical industry, has also seen an enormous growtli in this particular factory. 177 178 T h c C h i c a y o Starting in with kerosene oil lamps andaSOO-horse-power, belted, non-condensing engine, 500 horse-power in tubular boilers, one night watchman, an errand boy, and a few hundred men, this industry has grow^n until at present 300-KILO\VATT, ALTERNATING CIRRENT WESTINGHOUSE GENERATOR there are 12,000 incandescent lamps, 10,000 horse-power in compound condensing engines (of which 6,500 horse- power is electrically connected), 9,000 horse-power of watertube boilers, 1,000 horse-power of air hoist, twent}-- four w-atchmen, 7,000 men, a plant covering 85 acres of E led r i (• n I 11 a ii d h o o /,■ 17f) ground, and, last hut not least, 100 tclcplioiios to replace the solitary errand hoy. In 1o constructed tliat when the Electrical Handbook 18.5 pressure drops below 100 pounds, the needle, or hand of the gauge, completes an electric circuit through a control- ler, which starts the motor automatically. When the pressure increases to the desired amount, the gauge hand completes another circuit tlirough the controller and stops the motor. The controller is also waterproof and the whole installa- tion is so designed that its operation will not be inter- fered with in case the basement in which it is located should become filled with water. The outfit was designed to meet the specifications of the Underwriters Bureau of Fire Protection, which is coming to favor installations of this nature, after having investigated the subject very thoroughly during the past two or three years. The current for operating the above-described electric fire pump is obtained from the circuits of the Chicago Edison Company through its underground system of con- ductors, so that the operation of the pump would not be interfered with by a shutting down of the steam plant of the Marshall Field Building due to fire in the })uilding or other causes; nor would a shut-down of operations in any one of the Chicago Edison stations or substations deprive the pump of its source of power, as the Chicago Edison Company's system is so arranged that the current could be svipplied through their other stations. Rlectrically Opcratai Lift and Draiv Bridges in Chicago EFFECT A (J HEAT SAVING OVER STEAM In its industrial applications electricity is especially valuable in the operation of lift and draw bridges. The power necessary to open and close these bridges is not required all the time, but may l)e wanted at any moment, and in installations where steam is used for this purpose, ASHLAND AVENUE BHIDGE, Ol'EN it is necessary to keep tlie fire going at all times to meet the demands. Continually maintaining a proper steam pressure necessitates a large consumption of coal and consequently a high operating cost. The City of Chicago has found by actual experience that the cost of operating l)riuges has been greatly reduced by the substitution of electricity for steam, and a consideral)Ie saving in the time required to open and close the bridges has also been effected. As the electric power is consumed only when the bridge is in actual operation, the cost is small as compared with coal; the maintenance is also much less than with steam engines and boilers. 187 188 The Chic a y o Before the advent of steam operated bridges, the heaviest ones required several men to handle them, and the service was slow and unsatisfactory. Speed and control are the requisites of modern methods, and the .>*.-. ^ai- ASHLAND AVENUE BRIDGE, CLOSED old method of hand operation is iuisuital)le for the larger bridges. Chicago now has twenty bridges operated by elec- tricity, four operated by steam and twenty-four bv hand CLYBOURN PLACE BRIDGE, CLOSED power. The increase in speed obtained in turning the bridges electrically is estimated by the City Bridge Engineer to be 25 per cent over steam operation, and at least 75 per cent over hand operation. In some cases the old liand-operated bridges reciuircd from ten to E led r i cal H a n d b o o k 189 t\vcl\e niinutc'8 to make a (ivuirter turn, which can now be made in from thirty-five to forty seconds. Among the liridges operated by electricity are the following, and over some of them flows an enormous traffic : Adams St.; Clybourn Place; I^oomis St.; Clark St.; Dearborn St.; North Halsted St.; 18th St.; Jackson St.; Randolph St.; Rush St.; Van Buren St.; Wa.'^hington St.; Lake St.; North Western Ave.; and Wells St. For these bridges the street and elevated railway com- panies whose tracks cross them furnish the current at a cost of .f50 per ntonth or less, in some cases no charge CLYBOURN PLACE BRIDGE OPKX being made; excepting in the case of the Rush street bridge, for which current is obtained from the Chicago Edison Company at a cost of about $100 per month. The coal only for the steam-operated bridges averages about $63 per month, and the coal bill for the South Hal- sted street l)ridge alone amounts to over $200 a month. Some interesting data regarding a number of the elec- trically operated bridges was published in the Twenty- third Annual Report of the Department of Public Works for 1898, and the extract from this report tabulated here- with is of considerable interest. 1!)0 T h e Chicago MOTOR CONTROLLING PANEL AND K-10 CONTROLLER FOR OPERAT- ING CLYBOURN PLACE BRIDGE C H H o >^ < 2 O 1 .Si .ii .ii .ii w .k .ii 1 'u 't^ "C 'C 1 o o o ;^ CJ o 0) 3J i i 2i a; u ^ E K 3 Ii' — 2 S C3 -^ ^^ -^ — . •^ _ — ^^ s C8 c« :S tJ S C3 u u u. ^ M 0) a. oj i 1. 1; K aj 0/ 0^ ~ * a. 3J V 'C O 'C O ■f. ^ 'O O 73 X _r. i w ■-±-r.^'^^ -r.ii S ss J2S2S ^ z.^ '^'z ^~z '"'z 'c'c l?-23 E .2. §'^ •«5 =^. s Q 0"* C_ « c ^ B OPOr° *3 o^t-^o^ x^ •.r I o-* 0^0^ X^^iO^DCo "^o v^ =«:oxo tS 1 ^ 1 f— ^ 1 ^ 1^ « • 2 — ,', " ^ 1 ^ 1 ^ 1 ^1 ^ 1 i:TK7 wKOtsJcW c« zsB o« o«aW — — ^ccoi-< -tC'i ^ 'tc-l (M"N-H 1 t- __^ ^^ ^ Numl wings lually X , 05 . X . X •T t- T- ■ i ■ X -t ■? 1 H « o S 'i S'fcWS X ■ cr. I, T -.r 1 ; t! -Q m c -r ■ a-. >e^^ ^ -t >c <=|-= cc ^ c 0) c3 C to ^S'il _t, ■ _„ ■ !*. •-* ! c'j M rc "^.Btc^ ^ -^■^ ^>— . OJ t^ -*^«- -^ rt c ?^ « 1^ I3i •O (^ r-^^^ «— *^ < s — , ^ — — ,— i _i; _!, i. s s :S rf r- ^ ^ c i c i K Z. ffl c c _■_ _■_ r _ ::. ^ X s — -*— *^ o; " '^ - <— — 3^ r .a* ■^ 5 -jC ■r. I 1 X i: <: 0) X - r. - ~z «^ ^ -^ ci =15 n ~ (lams slilan ivisio { Riv ivisio {Can i^ 5 3 S < < ^ Z - ~ 7. ^ ^ ^ .y o o *n a^ 1j o X X o o _aj _1; 1 ^ U^ :::^ 2 £ E a 2 s _^ , ^^ "Su __ ri Ti rt rt — — ~ :« t£ ^ c a> C ^ ■z o 0, ^^ -3 X a; O X •x~: X ■- C £ Z. ^^ _5 = X 'z -5 •^ M aj c -^ "c S £ £ -3 ?I u -^ ^ L. S s g V i^ 1 3 §5 sis ^C ^ r^ J5 k: s s c S p^ mO ^Sf 5 •-; C ^ CI X" — X ? o«c - Xo k7 - 'T i l-H C c- C d ^ K ^ a 7 d 0" '^^:j c^ — — IN — b. --,— — . — . -.^-. .^, — - — -r — — — ^ ^— ^ I|:& X CI 115 i^'^i -T X 1^ 05 05 ra"^ c x. |o-< Ci Si's s ^fcW £ ■M I; X -.c fe-^ S c 1- o li.t 1 c to cc o Qi =3 C 2 = -i 3 -c. *■ p»* -*< 3 o.S B : ■M M > m > s 'C, ^^•-^ -2 "E St; c3 oj roxim !ight c ablep Bridg tn T**^ o o •t" *^ O c o o lO 5 £ o — o a^So H < s ^.^ -■- ■- J; _i ^ a. ? ? > ? Is & >i X X CS ^ a d: £ c ffi C 5 1 1 3) 1 is — .t: £ OJ K 0) 0) "7 S c c E I c c t r i c (I / II (I )t (I I) o (} k 193 It will 1)C' noted that tin" bridges ou which the data is given in this tabulation have an average weight of over ()()() tons, while each briclgc swings on an average MOTOR SUSPENSION, CLYBOURN PLACE BRIDGE nearly 5,000 times a year, three minutes being the average time required for each swing. The accompanying cuts illustrate the Ashland avenue bridge open and closed, and the Clybouru Place bridge open and closed, also a portion of the operator's room and the operating machinery below the liridge. 400-KILOWATT WESTINGHOUSE GENERATOR AT FAC'TOHV OF W. W. KIMBALL COMPANY II \ ir. Ki)uball Company In tlie manufacture of pianos and organs the Kiniljall Company use electric power tlirougliout their factory. A 400-kilo\vatt,Westingliouse, three-phase, 7,200-alterna- tion, 440-volt generator, 100 revolutions per minute, as illustrated in the view, carries a load of 500 horse-power of induction motors in various sizes, which are used to drive line shafting and various kinds of machinery pecul- iar to this industrv. 195 The Illinois Sfccl Coiipaiiy Among the ino.st interesting of all nianufaeturing plants in which electric power is used are those engaged in the manufacture of iron and steel. The magnitude of the electrical equipment required for large plants of s\ich character, and the wide divergence of uses to which elec- tric power is put, together with the somewhat peculiar VIEW OF DIRECT CURRENT STATION HEP'ORE REMODELING features of application, afford tjie interest to the elec- trical engineer. The plant of the Illinois Steel Company at South Chicago perhaps may be taken as typical of this class of works. In that plant, the use of electric power began about the year 1894, by the installation of a 100- kilowatt generating station. Many difficulties were met, 197 198 The Chicago some of which were successfully overcome at that time, and some of which caused much prejudice in the minds of some of the mill operatives, which operated to restrain the rapid increase in the use of electric power. Notwith- standing these obstacles, however, in a couple of years it was found necessary to have generating capacity five times as great as that originally installed. Within two j^ears more, it was necessary to build a new station of 1,100-kilowatt capacity. By 1901 this had been doubled again. By 1903 it was again increased, and, at the PRESSING REVOLVIXG FIELD OF 2,000-KILOWATT WESTIXGHOUSE GENERATOR ON ENGINE SHAFT present time, a new station of 4,CCC-lcilowatt capacity- is being added to the present station of 3,000 kilowatts. During the time covered by these various extensions, the attitude of steel men toward electric power rapidly changed from opposition to enthusiastic encouragement. At first it was thought necessary always to provide a steam reserve for every electric motor installed, and also to l)e careful in installing motors to see that no depart- ment would he shut down by the crippling of the source of electric supply. The continued use of motors, how- ever, demonstrated this type of macliinery to be fully as Electrical Handbook 199 reliable as any other type and, in fac-t, consideraljly more so. Within a very few years it was found tliat the con- dition had practically been reached where cutting down the source of electric supply would seriously disable all departments of the steel plant. When it was found that this condition existed, it was evident to all that the proper metliod was to extend the use of electric power as widely as possible and to provide ample reserve in generating capacity. In pursuance of this idea, the Illinois Steel Company has taken every precaution pos- sible to insure the continuity and reliability of service. To insure absolute continuity of service, there are two separate generating stations. In one there are four OKE BRIDGE, SOUTH CHIC.\GO direct current units, aggregating 2,800 kilowatts, and in the other, under process of construction, there are two alternating current units, each 2,000 kilowatts. The two electric stations are connected by means of one 1 ,000- kilowatt and two 500-kilowatt rotary converters, which float on the system, being connected to both alternating current and direct current sides. Through them, when needed, power can be supplied to the direct current mains from the alternating current station, or to the alternating current mains from the direct current station. Further reliability is secured by reason of the fact that the boilers furnishing steam to the engines in both stations are fired by blast furnace gases from separate >()urces of supply. 200 T h e C h i c a 90 whose mains are connected together, with the further provision that either battery of boilers can be fired with coal, should the gas fail. The accompanying illustrations show the direct cur- SKIP HOIST, ILLINOIS STEEL, COMPANY rent station and give a view of the new alternating current station, taken during the interesting process of pressing the revolving field of a 2,000-kilowatt Westing- house generator on the shaft of the engine by which it is to be driven. K I c ct r ic a I II a ii d h o o /,• 201 The current, both alternating and direct, is trans- mitted throughout the plant hy overhead construc- tion. The alternating current generated at 2,200 Aolts 3-phase, 25-cycle, is stepped down at various points, through banks of static transformers, for use in motors of comparatively small size, 440 volts. Large motors are operated at 2,000 volts; 3,000 horse-power MOTOK CEMENT PLANT, ILLINOIS STEEL COMPANY is stepped up in the alternating current station by static transformers to 20,000 volts, and transmitted ten miles down the lake shore to a cement plant having daily output of 4,000 barrels. There is no power generated at the cement plant, which, therefore, depends entirely upon the transmission line. There are here used induction motors of the short-circuited secondary type, aggregating 3,000 horse-power. 202 The Chicago At two points in the yards of tlie Steel Plant proper there are located two rotary converter substations, each containing a 500-kilowatt rotary converter, transform- ing alternating current to direct current. This comprehensive plant, coupled with first-class construction, precludes break-downs of any extent and enables any small break-dowai to be isolated, fo that its effect is limited to the smallest degree. The electric motor is used in almost every process, and among such uses there are a number of interesting appli- cations. The accompanying illustration gives a view of a large ore bridge which spans the ore yard- This bridge is operated electrically in all of its movements, and resembles a huge traveling crane. Another accompanying view illustrates the applica- tion of motors to skij? hoists, the control being automatic and affording safeguards against exceeding the limits of travel when dumping ore into the blast furnaces. By means of the electric motor used in driving a cold saw for cutting steel rails, it has been found possible to so adjust the speed of the saw that maximum cutting capacity, minimum wear and minimum power expended can be secured with each size of rail cut, a condition which could not be attained when the cold saw was driven by a steam engine. Motors are used extensively throughout the plant for traveling cranes. Gantry cranes, hoists, elevators and blowers; they are used to drive line shafting, machine tools, incandescent and arc lighting generators, and, in fact, are put to every purpose within the capacity of an electric motor. In fact, the use of electrically trans- mitted power is so extensive in this plant that after the gradual growth to the present condition, it is found that every essential process in the manufacture of iron and steel is dependent, either directly or indirectly, upon the continuity of service rendered by the machinery em- ployed, which is absolutely insured by the arrangement of the stations in the circuits. At the works of the Illinois Steel Company at Joliet. E led r i c a I II a n d h o o k 203 Illinois, there i.s used a 500-kilo\vatt \Vestiiifi;liouse rotary converter (which is shown, togetlier with station switch- board, in the accompanying photograph), for the purpose of transforming alternating currents purchased from the local power company into direct current for use in the mills. 500-KILOWATT ROTARY CONVERTER AND STATION SWITCHBOARD At the North Works of this company there is a direct current plant of approximately 300-kilowatt capacity, furnishing current for motors throughout the plant; and at the Milwaukee Works there is a direct current plant of approximately 700-kilowatt capacity, carrying large loads of various sizes for use in the works. -^" ^wi i E!^ THE LIBRARY UNIVERSITY OF CALIFORNIA Santa Barbara THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW. Series 94H2 A 000 587 483 9