THE LOCOMOTIVE LABORATORY 
 
 UNIVERSITY OF ILLINOIS 
 
 Urbana, II.LINOIS, NovKMBER, 1915 
 
The axles and tires are of the highest grade of heat-treated carbon 
 steel and were donated by the Midvale Steel Company. Provision has 
 been made for replacing the 52-inch wheels by 72-inch wheels for test- 
 ing high speed locomotives, where the use of the smaller wheels would 
 involve rotating speeds as high as 530 revolutions per minute. 
 
 Bearings. — The bearings for the supporting- wheel axles are self- 
 aligning, their shells being carried in spherical sockets which form the 
 upper part of the pedestal. The journals are 9I/2 inches by 20 inches, 
 and the axles bear on the underside only. Oil for lubrication enters 
 the bearing cap at two points and is supplied under head from an 
 elevated tank. The pedestal is made in two parts, so that by removing 
 the lower section, its height may be adjusted to provide for the 72-incli 
 supporting wheels. This arrangement will continue to bring the top 
 edge of the larger supporting wheels level with the outside track. The 
 base of the pedestal is secured to a massive cast-iron bed-plate by 
 T-bolts held in slots running the entire length of the bed. Each bed- 
 plate consists of three sections placed end to end, 18 inches in height 
 and 36 inches wide over all. The length of the present bed-plate is 
 42 feet, which provides for a maximum driving-wheel base of 36 feet, 
 and the foundation is built to receive two more 14-foot sections of bed- 
 plate. The supporting machinery rests on a concrete foundation 12 
 feet wide and 93 feet long, which varies in thickness from 3I/2 feet at 
 the front to 5 feet at the rear end. The rear end is surmounted by a 
 pyramidal base of reinforced concrete, to which the dynamometer is 
 bolted. 
 
 Hydraulic Brakes. — Supported in this way the driving wheels are 
 free to turn and the power produced at the driving wheel rim is ab- 
 sorbed by means of the brakes shown in Fig. 3, 4, and 10. One of 
 these brakes is mounted on each end of each supporting-wheel axle. 
 Each brake consists essentially of three cast iron discs (C, Fig. 10) 
 which, bolted to the cast iron hub (F), are keyed to the supporting 
 axle and form with it an integral revolving element. These three discs 
 rotate between 1/16-inch copper diaphragms (D), bolted to the rim of 
 a stationary housing (H), and flanged over the edges of the floating 
 rings (E) and of the housing, to which they are secured by means of 
 the expanding rings (G). The housing is prevented from turning by 
 means of the links (L) attached to the bed-plate. The rubbing sur- 
 faces of the discs and diaphragms are lubricated with a medium grade 
 of cylinder oil which enters the brake under pressure through the oil- 
 
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Iioader (N) at the pcripliery oi' the tliscs, and tliroii^di tlie oil-duct 
 (K). The oil is taken off at M as it oozes out around the disc hub. 
 The diaphrajj^ms form also within the casing four water compartments 
 which have no communication whatever with the compartments in 
 which the discs rotate. Water at about 60 dc^. F. is foi'ced throuf,'h 
 3-inch hose connections into the bi*ake at the lower header (B) and 
 leaves through the upper header (A). The amount of water passing 
 through any individual brake and the water pressure within the brake 
 may be regulated at will by means of suitable valves in the piping. 
 The brake load is controlled by thus modifying the water pressure. 
 This is accomplished simultaneously for all of the brakes by means of 
 tlie large control-valve in the brake supply main, shown in Fig. 8. 
 The auxiliary brake-valves and gages shown at the left in this same 
 figure permit the separate adjustment of load on each brake. Each 
 of these brakes has the capacity of absorbing 450 horse power, having 
 l)cen designed to develop a resisting torque of 18 000 pounds-feet at 
 speeds up to 130 revolutions per minute. This capacity allows for a 
 considerable increase in wheel loads above that which could be im- 
 posed by the most heavily loaded driver of the present day. 
 
 Placing tlie Locomotive. — Fig. 3 shows the mounting machinery 
 arranged to receive an eight-driver locomotive. The top of the sup- 
 porting-wheels is level with the main floor of the building and one- 
 fourth inch higher than the outside track. Before the locomotive to 
 be tested is placed upon the plant, its wheel-spacing is determined and 
 the supporting- wheel centers spaced accordingly. The tender having 
 been removed, the locomotive is backed into the laboratory and onto 
 the temporary track shown in place between the supporting- wheels. 
 The drivers run on their flanges over the temporary track, which leaves 
 their treads free to engage the supporting-wheels, so that when the 
 locomotive is properly placed the supporting-wheels carry all of the 
 weight except, of course, that borne by leading or trailing trucks. The 
 temporary track being relieved, may be removed. Mounted in this 
 way, the locomotive is held in place and prevented from moving for- 
 ward or backward by means of the dynamometer draw-bar, which is 
 supplemented by two safety-bars that come into play in case of failure 
 of the draw^-bar. These three bars are shown in Fig. 8. Forward and 
 trailing-truek wheels are carried on track sections which are level with 
 the supporting wheels. 
 
 TJie Dynamometer. — The dynamometer, the chief function of which 
 is to permit the tractive force of the locomotive to be measured, is 
 
Fig. 4. An Exterior View of the Brakes. 
 
 Fig. 5. The Weighing Head and Pedestal of the Dynamometer 
 
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 Fig. 6. Sectional Pl-A 
 
OF THE Laboratory. 
 
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 shown in Fig. 5, 6, and 8. It is of the Emery type and consists 
 essentially of two parts : the weighing head, carried on a pedestal and 
 shown in Fig. 5, and the measuring and recording scale shown in Fig. 
 8. The weighing head may be raised or lowered to suit the height 
 of the drawbar of any locomotive. Within the weighing head is an 
 enclosed oil-chamber with a flexible wall or diaphragm, which receives 
 and balances any force transmitted through the drawbar of the loco- 
 motive. The pressure within this oil-chamber varies with the load, 
 and is transmitted through a copper tube of small bore to a smaller 
 oil-chamber known as the reducing chamber, located in the case with 
 the measuring apparatus. The pressure thus produced in the reduc- 
 ing chamber moves the beam of a substantial but sensitive scale which 
 measures the tractive force of the locomotive. 
 
 In order to prevent undue shocks from taking place within the 
 weighing head of the dynamometer on account of variations in the 
 force in the drawbar, an initial load of 50 000 pounds is imposed upon 
 the oil behind the diaphragm by means of the capstan and springs 
 located at the rear of the weighing head and shown at the left in Fig. 
 5. The weighing head of the dynamometer is so designed that by an 
 adjustment of the capstan the tractive effort may be measured whether 
 the locomotive drivers are turning forward or backward. For the 
 sake of accuracy in determining the drawbar pull it is essential that 
 the locomotive drivers be placed and maintained with their centers pre- 
 cisely above the centers of the supporting-wheels. To satisfy this re- 
 quirement the longitudinal travel of the dynamometer drawbar from 
 no load to full load must be reduced to a minimum. In this instrument 
 the range of movement is only three one-thousandths of an inch. The 
 scale beam reads directly to 20 000 pounds in 100-pound divisions, and 
 a vernier gives readings to ten pounds. For drawbar pulls of more 
 than 20 000 pounds, weights may be added as required. The dyna- 
 mometer will measure drawbar pulls as high as 125 000 pounds. 
 
 A feature of interest in the design of the scale lies in the fact that 
 the adjustment of the poise weight on the scale beam may be made 
 automatically. This is accomplished by means of a small motor which 
 is mounted on the scale beam and geared to a screw which passes 
 through the poise weight. Attached to the scale beam is a contact 
 arm, and any movement of the beam in either direction causes a series 
 of mercury-cup contacts ; the number of contacts depending on the 
 amount of deflection of the beam, which in turn is caused by a change 
 
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 ill the load. When contact is made, an electrical circuit is closed and 
 the motor runs in the direction required to bring the poise weij^ht to 
 a position of e(iuilibriuin. As soon as the load is balanced, the circuit 
 is broken and the motor stops. This operation is repeated as often as 
 the load changes, and is practically continuous. The action of the 
 poise weight may also be controlled by a hand switch. 
 
 Water and Coal Supply. — The general water supply of the Univer- 
 sity is from driven wells, the demand upon which at times approaches 
 their full capacity. In order therefore that the water which passes 
 through the brakes shall not be wasted, provision has been made for 
 collecting, cooling, and recirculating it. For this purpose a 100 000- 
 gallon concrete storage reservoir (sec Fig. 1) has been built in the 
 ground outside of the building. A supply pump for the brakes draws 
 water from this reservoir through a 6-inch main and pumps it through 
 the main control valve to a header, whence it is distributed through 
 auxiliary supply control valves to the several brakes; after which it 
 flows back through another set of auxiliary back-pressure control 
 valves to a sump located in the basement of the laboratory. ( See Fig. 
 6.) The water is drawn from the sump by another pump and forced 
 through five 2-inch whirling-spray nozzles above the surface of the 
 water in the reservoir. Water direct from the University mains may 
 also be used in the brakes when desirable. 
 
 Water for the locomotive boiler may be drawn from the reservoir 
 or direct from the University mains, and forced by a separate pump 
 to two elevated tanks which are shown in Fig. 3 and 7. Each of 
 these tanks has a capacity of 2000 pounds and rests permanently on 
 a platform scale. At a supply pressure of 45 pounds, each tank can 
 be filled, weighed, and emptied in two and one-half minutes. From 
 the weighing tanks, tlie water falls into the 18 000-pound capacity 
 feed tank below, and thence passes through two 4-inch supply pipes to 
 the locomotive injectors. Water for the hydraulic elevator used in 
 raising coal from the main floor to the firing platform may be taken 
 from the University mam or from the storage tank. In either case 
 the pressure is maintained at 60 pounds by a throttle-control valve on 
 the supply pump. By these provisions in the piping, reservoir water 
 alone may be used for feed-water, brakes, and elevator. 
 
 The coal-room shown in Fig. 6 occupies the rear end of the build- 
 ing. It is 22 feet wide and 40 feet long, and has a storage capacity 
 of 300 tons. Coal for the tests is loaded into 1000-pound capacity wag- 
 ons, run out onto the scales, raised by the elevator to the firing plat- 
 
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 Fig. 7. A Cross Section Through the Middle of the Laberatory. 
 
 form, and there dumped. The firing platform is adjustable in height 
 so as to suit the deck of any locomotive cab. The elevator has a ca- 
 pacity of 2000 pounds. It is also used to raise ashes from the level of 
 the basement. 
 
 The Exhaust System.— Reeogmzing the value of accurate deter- 
 mininations of the total amount of cinders lost through the stack of 
 the locomotive, it was early decided that if possible some means should 
 be incorporated in this plant to collect all of the solid matter which 
 passes through the locomotive front end. Preliminary designs of a 
 cinder catcher which should have sufficient capacity to pass the total 
 volume of waste gas, exhaust steam, and entrained air, and at the same 
 time collect all the cinders from the largest modern locomotive work- 
 ing at high power, made it clear that such a collector would be too 
 
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14 
 
15 
 
16 
 
 Fig. 11. Ckoss Section Through the Cinder Collector and Stack. 
 
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 large to be located conveniently within the building. Another point 
 considered in the design of the exhaiust system was the necessity of a 
 stack of suflicient height to insure that the exhaust gases would be 
 discharged far enough above ground to prove inoffensive to occupants 
 of neighboring residences and University buildings. For this purpose 
 it wras decided that a stack 8 feet in diameter and 80 feet high would 
 be required. Further study made it apparent that these two decisions 
 could be embodied in one structure combining the cinder separator 
 and the stack. This has been accomplished in the construction repre- 
 sented ill cross-section by Fiji'. 1 1, and wliich is located outside and at 
 the rear of the laboratory. 
 
 The system will be most easily understood by following the course 
 of the exhaust gases after they leave the locomotive stack. (Fig. 
 () and 7.) The <>-asos and exhaust steam are dischai'gcd across an 
 open space above the locomotive stack into a steel exhaust elbow, which 
 carries them up and over to a horizontal duct running through the cen- 
 ter of the roof -trusses of the building. The gases, exhaust steam, and 
 solid matter are drawn through this elbow and duct by the exhaust 
 fan, located near the roof at the rear end of the building. They are 
 then passed through a breeching or flue to the separator previously re- 
 ferred to, the action within which may be best explained by reference 
 to Fig. 11. The cinder-laden gases enter the separator at B and in 
 order to leave, they must pass downward and around the sleeve A. 
 This operation gives them a whirling motion, which causes the cinders 
 by centrifugal force to move toward the outside wall, along which they 
 drop to the hopper below, while the gases pass downward and out 
 through the mouth of the sleeve. The cinders collecting at the bottom 
 of the hopper are drawn off, weighed, and analysed between tests. The 
 separator is surmounted by a 45-foot radial brick stack, through which 
 the gases and steam are finally discharged. 
 
 On account of the corrosive nature of the mixture of exhaust gases 
 and steam, it was necessary to avoid the use of metal throughout the 
 exhaust system, as far as it was possible to do so. The exhaust elbow 
 which receives the gases from the locomotive stack is necessarily made 
 of steel and needs occasionally to be renewed. The horizontal duct, 
 running through the center of the roof -trusses, is made of a hard and 
 tough asbestos board known as ''Transite," which is proof against 
 corrosion. This duct is seven feet in diameter, and is built up in sec- 
 tions so that its length may be varied to suit the position of the locomo- 
 tive stack. The final adjustment of the elbow above the stack of the 
 
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 locomotive is obtained through the medium of a telescopic connection 
 between the elbow and the duct. The fan has a runner six feet in diam- 
 eter, and at a maximum speed of 300 revolutions per minute, will pass 
 140 000 cubic feet of gas per minute. The breeching between the fan 
 and separator is also built of transite, and has a minimum cross-sec- 
 tional area of about 24 square feet. The outer shell of the separator 
 is built of reinforced concrete, and it is lined throughout with a course 
 of hard red brick as protection from the corroding action of the gases. 
 Between the lining and the shell is a 2-inch air space which acts as an 
 insulator to protect the shell from overheating. Any leakage of gas 
 through the lining into the air space is vented to the outside air 
 through openings which are provided in the shell, and which serve also 
 to circulate cool air through the air-space. Both the inside sleeve and 
 the hopper are built of reinforced concrete. The stack itself is un- 
 lined, but is laid up with acid-proof cement. Provision was made in 
 the design for traps in the bottom of the horizontal duct, whereby any 
 solid matter that should accumulate within the duct could be removed 
 and weighed. Experience has proved this to be unnecessary, as all 
 portions of the duct and breeching have been self -cleaning under all 
 test conditions thus far encountered. 
 
THE UNIVERSITY OF II.LINOIS 
 
 THJfi STATE UNIVERSITY 
 URBANA 
 
 EDMUND J. JAMES, Ph.D., LL. D., President 
 
 THE UNIVERSITY INCLUDES THE FOLLOWINQ DEPARTMENTS: 
 
 The Graduate School 
 
 The College of Liberal Arts and Sciences (Ancient and Modern Languages 
 and Literatures; History, Economics and Accountancy, Political Science, 
 Sociology; Philosophy, Psychology, Education; Mathematics; Astronomy; 
 Geology; Physics; Chemistry; Botany, Zoology, Entomology; Physiology; 
 Art and Design) 
 
 The College of Engineering (Architecture; Architectural, Ceramic, Civil, Elec- 
 trical, Mechanical, Mining, Municipal and Sa,nitary, and Eailway Engi- 
 neering) 
 
 The College of Agriculture (Agronomy; Animal Husbandry; Dairy Husbandry; 
 Horticulture and Landscape Gardening; Veterinary Science; Agricultural 
 Extension; Teachers' Course; Household Science) 
 
 The College of Law (three-years course) 
 
 The School of Education 
 
 The Courses in Business (General Business; Banking; Accountancy; Railway 
 Administration; Insurance; Secretarial; Commercial Teachers') 
 
 The Course in Journalism 
 
 The Courses in Chemistry and Chemical Engineering 
 
 The School of Railway Engineering and Administration 
 
 The School of Music (Voice, Piano, Violin; four-years course) 
 
 The School of Library Science (two-years course) 
 
 The College of Medicine (in Chicago) 
 
 The College of Dentistry (in Chicago) 
 
 The School of Pharmacy (in Chicago; Ph.G. and Ph.C. courses) 
 
 The Summer Session (eight weeks) 
 
 Experiment Stations: U. S. Agricultural Experiment Station; Engineering 
 Experiment Station; State Laboratory of Natural History; State Ento- 
 mologist's Office; Biological Experiment Station on Illinois River; State 
 Water Survey; State Geological Survey. 
 
 The library collections contain (July 1, 1915) 414,365 volumes, including the 
 library of the State Laboratory of Natural History (8,100 volumes), the 
 Quine Medical Library (14,000 volumes), and the library of the School of 
 Pharmacy (2,000 volumes) 
 
 For catalogs and information address 
 
 THE BEGISTEAB 
 
 Vrtana, Illinois 
 
3 0112 105630237