economic comparison in favor of 265-volt circuits. Our experience indicates tha t ofiice areas, trouble lamps, and portable tools require widespread convenience out­lets 33 per cent to 100 per cent as numerous as lighting outlets. If panel-boards and small transformers are added to the 265-voh system, the latter is increased con­siderably in cost. And when the small 1-, 2-, or 3-kva transformers are added will they he tapped to a 265-volt circuit (requir­ing a special transformer) or will a special 460-volt circuit be run just for these trans­formers?

The 265/460-volt system, as presented, is not a universal system applicable to all types of lighting units as are some of the other systems presented. For a t rue com­parison, all systems estimated should be able to supply all t5φes of lighting units, or the estimates should include the cost of fix­tures and lamps to give a t least approxi­mately equivalent illumination results.

We see no advantage in using 3-phase transformation for the 460/120-208-volt lightmg circuits. Unless 3-phase 208-volt service is required for special purposes, single-phase transformers are lower in cost and usually can be balanced acceptably

across phases on the 3-phase 460-volt cir­cuit. Using single-phase transformers and with certain other refinements, we have been able to reduce costs for the 460-volt com­bined power and light system from 10 per cent to 25 per cent below the cost of other acceptable system(s).

Strangely enough, in considering the 265-volt system, we have been advised a t times tha t to specify such voltage (or 277 volts) for transformer secondaries will entail de­layed delivery because the voltage is non­standard.

We commend Mr. Kahler and Mr. Bell for the use of 460 as a circuit voltage, which recognizes the obvious but sometimes over­looked fact tha t 480 on a transformer name plate does not necessarily, in fact seldom, represent the proper utilization voltage.

W. H. Kahler and R. N. Bell: I t certamly was not the intent of this paper to encourage high-voltage distribution systems for all types of lighting layouts. I t is t rue tha t 120 volts is best for incandescent lighting and, where incandescent lamps predominate in the over-all lighting load, a 120-volt distribution voltage is best. However,

where all or a high percentage of the light­ing load is fluorescent or mercury, the higher voltage distributions will prove to be more economical.

Where small dry-type transformers are required for incandescent lamps and re­ceptacle circuits, these transformers are generally connected to 460 volts line to line rather than to 265 volts line to neutral. The use of single-phase versus 3-phase dry-type transformers is determined by the amount and type of load to be served and also the particular engineering preference.

In the past most 460-volt 3-phase distri­bution systems have been supplied by delta-connected transformers because industry has preferred the ungrounded secondary for power equipment. In recent years some industrial plants have seen advantages to grounded power systems and also have seen the advantages to 265 volts for lighting. Therefore, the 265/460-volt 4-wh-e Y-con-nected transformers have become uni­versally available from the major manu­facturers of transformers and unit substa­tions. If the demand for 265 volts for lighting increases, we would expect the Y-connected transformer to become standard apparatus for all suppliers.

A n Interurban Becomes a Railroad

C. H. JONES ASSOCIATE MEMBER AIEE

ON E O F the most impor tan t advances in rail t ranspor ta t ion after the turn

of the century was the introduct ion of electric t ract ion motors for passenger train service. This boom s tar ted a criss­cross of short in te rurban electric lines throughout the count ry with the idea in mind of reaching ou t and covering more territory. A t t he t ime of this boom there were two t rends of t hough t in t h e t rac t ion field—alternating current and direct cur­rent.

In M a y 1906 the Chicago Lake Shore and South Bend Rai lway Syndicate was formed to acquire t he securities of t he Chicago Lake Shore and South Bend Rail­way Company, a successor to t h e Ind iana Air Line Rai lway Company . This syn­dicate, favoring a-c propulsion power, started construction on an in terurban line from South Bend, Ind . to Chicago, 111.

The original electrification of the rail­road in 1908 was a 6,600-volt single-phase a-c contact system. T h e construction consisted of one 1/2-inch Siemens-Mart in steel cable as the main messenger, one 4/0 copper intermediate wire and one 3 /0 grooved iron contact wire. T h e inter­mediate wire was suspended from the main messenger b y means of rigid

hangers. T h e steel contact wire was in t u rn suspended from the intermediate wire b y means of bronze duplex clips. T h e duplex clips were spaced equidis tant between hangers and provided a good feeder connection.

This ca tenary system was supported by a wooden pole line which, upon i ts completion, was considered by m a n y as t he finest pole line in the country. T h e poles were 45-feet long-leaf yellow pine, creosoted and set wi th a concrete collar a t the bo t tom abou t 3 feet in outside diam­eter and 1 foot thick and another similar collar jus t below the surface of the ground. T h e pole spacing was 167 feet on tangent t rack with shorter spacings on curves varying with the degree of the curve. On single t rack between Gary and South Bend, Ind. , the poles were located on the south side of the t rack approximately 9 feet from the center of the t rack. I n double-track terr i tory between Gary and the Illinois-Indiana s ta te line, the poles were located between the t racks . F rom the s ta te line to Ken­sington, 111., t he poles were placed on the outsides of bo th main tracks.

At tached to these poles were 9-foot tee section, bare steel m a s t arms. T h e main

messenger wire was supported by a pin-type insulator a t tached to the top of the mas t a rm. A 5-foot wood steady strain was placed between the mas t a rm and the intermediate and contact wires a t the proper angle so as to steady the wires from wind effect.

Wi th this 25-cycle 6,600-volt a-c system only two substat ions were needed to furnish the necessary propulsion cur­r en t required b y the trains. T h e main power p lan t was located a t Michigan Ci ty with one substat ion located 22 miles east of Michigan Ci ty and the other one approximately 33 miles west. Trans­mission lines a t t ached to the wood pole line fed the substat ions from the main power stat ion.

T h e single t rack port ion of the fine, extending from Gary to South Bend, was equipped with au tomat ic semaphore-type block signals. These signals were two position and used the left-hand upper quadran t . The t rack circuits for these signals were 60 cycles, al ternat ing cur­rent , so as not to be interfered with by the 25-cycle propulsion current . A 2,200-volt a-c signal pr imary line fed the signal system with a pole-mounted transformer

P a p e r 53 -35 , r e c o m m e n d e d b y t h e A I E E L a n d T r a n s p o r t a t i o n C o m m i t t e e a n d a p p r o v e d b y t h e A I E E C o m m i t t e e on Techn ica l O p e r a t i o n s for p r e s e n t a t i o n a t t h e A I E E W i n t e r Genera l Mee t ing , N e w Y o r k , N . Y . , J a n u a r y 1 9 - 2 3 , 1953. M a n u ­scr ipt s u b m i t t e d Oc tobe r 2 3 , 1952; m a d e avai lable for p r i n t i n g N o v e m b e r 28 , 1952.

C. H . J O N E S is w i t h t h e Ch icago S o u t h Shore and S o u t h Bend R a i l r o a d , Mich igan C i ty , I n d .

M A Y 1 9 5 3 Jones—An Interurban Becomes a Railroad 9 9

Figure 1 . A pair oi 900-class 100-ton locomotives, equipped with 2-way space radio, operating in multiple unit

Figure 2. One of the 800-cldss 275-ton locomotives pulling freight train through "ideal section" near Gary, Ind.

a t each signal location to step the 2,200 volts down to 110 volts for motor opera­tion and another t ap further reduced it to 12 volts for the track circuit.

The railroad had two full metallic cir­cuit telephone lines extending from Kensington to vSouth Bend with the main switchboard located in the general oflices a t Michigan City. One circuit was used exclusively for dispatching and the other for the general business of the railroad.

T h e original t rack consisted mainly of 70# ASCE Bessemer steel rail on 8-foot creosoted red oak cross ties ballasted to a depth of 6 inches with bank run gravel.

In March 1908 five in terurban coaches were delivered, b u t it was not unti l Ju ly of t ha t year t h a t t ime table number 1 was issued inaugurat ing regular service be­tween South Bend, Ind. and Michigan Ci ty , Ind . with a running time of 1 hour and 30 minutes. In September of the same year regular service was extended to Gar\^ In April 1909 scheduled trains were pu t in service between South Bend, Ind., and Kensington, 111., where passengers t rans­ferred to Illinois Central suburban trains for downtown Chicago.

In M a y 1912 an agreement was made with the Illinois Central whereby Lake Shore Line coaches would be handled by IlHnois Central suburban steam engines to the Chicago terminal a t Randolph Street. By switching the cars to the Ilhnois Central at Kensington, i t was possible to ride from South Bend to Randolph Street wi thout necessitating a change.

The passenger equipment included 11 passenger motor cars and eight combina­tion motor and baggage cars weighing 55 tons each and at ta ining a speed of 69 miles per hour. There were also ten 50-foot trailers weighing 27 V2 tons and four 60-foot trailers of about the same weight.

The electric equipment on the motor cars included four Westinghouse number 148 single-phase motors ra ted a t 125 horsepower equipped with mult iple-unit controllers with five points for accelera­tion. The controller was not equipped with a dead-man control, al though the controller would move to off position if released. A 6,600-volt au to t rans-former was used to reduce the incoming voltage for use on the car. Two tract ion motors were permanent ly hooked in series, and the maximum voltage tap on t rans­former was 800 volts. The control volt­age, which operated only the contactors, was furnished from a 18-volt9-cell ba t tery , charged on the floor and changed each t ime the car was shopped for inspection. Lighting on the motor cars was taken from the 110-volt t ap on the transformer. T h e headhghts were originally carbon arc oper­at ing from 110 volts, bu t were later changed to 6 vol ts using a 110 to 6-volt transformer.

All of the cars were equipped with one pan tagraph and a t least one trolley pole. I t was necessary for the t rains to stop a t each end of the cities and operate a changeover switch under the cars, which permit ted the operation of equipment on 800 volts through the city streets and 6,600 volts outside of the cities.

After about 15 years of operating, freight service was s tar ted and two 70-ton Westinghouse freight locomotives and a few freight cars were purchased.

In the summer of 1925 the ra i lway 's value had depreciated to only a per­centage of the original outlay. Track, equipment, signals, and stations were virtually ready to fall apar t . The Chicago Lake Shore and South Bend Railway had collapsed financially under the heavy pressure of high costs during World War I. Parallel hard-surfaced

roads and growing motor transportat ion threatened to strip it of possibilities for the future. I t was forced into receiver­ship. The Midland Utilities Company, operating a number of gas, electric, and t ransporta t ion companies, realizing the strategic location, became interested in the insolvent Chicago Lake Shore and South Bend Railway. They could fore­see a region destined to become a summer vacat ion area with great industrial cities.

After a survey was made by a group of Midland Utilities t ransportat ion engi­neers, this property was purchased and the Chicago Lake Shore and South Bend Railway became the Chicago South Shore and South Bend Railroad.

Up until this t ime the Ilhnois Central suburban service was steam operation. Due to the growth and frequency of service, the Illinois Central deemed it necessary to abandon steam engines in favor of electric traction using 1,500 volts direct current. Because of the close association of the IlHnois Central com­muter service and the South Shore inter­urban service, the Midland Utilities immediately converted to 1,500 volts direct current for propulsion power in order to establish a terminal in downtown Chicago, by running on the Illinois Central t racks from Kensington to Randolph Street, a distance of 14 miles.

When the rebuilding problem arose, the management a t t h a t t ime had to choose between a light overhead col­lection system with separate feeder for conductivi ty or a system whereby all the conductivi ty is placed in the contact and supporting wires. After much consider­ation the la t ter- type construction was selected.

In converting to the new system, the management decided on using the same pole line as the old poles were considered adequate for the new type of construc­tion. Having been previously set in con-

1 0 0 Jones—An Interurban Becomes a Railroad M A Y 1 9 5 3

Crete, they were secure enough to with­stand the increased loads imposed by the new catenary; therefore, only a minimiun amount of straightening was required and the pole line was ready for the conversion operation. On the Kensington and Eas t -em section. Bates expanded steel trusses were a t tached between the poles to sup­port the catenary over the double t rack main line. Suspension insulators were clamped to these trusses and the main catenary messenger a t tached to them. On the center pole and single pole over­head construction an adjustable type of galvanized bracket a rm was installed. The main messenger was a t tached to an insulator on top of the mas t a rm similar to previously ment ioned 6,600-volt con­struction. This new-type a rm eliminated the heavy rust ing condition experienced with the earlier-type construction. All pole spacing on t angen t t rack remained a t 167 feet except on a portion of t rack paralleling the New York Centra l Rail­road immediately east of Gary .

The new construction of the catenary, carried out between Gary and Kensington consisted of one 0.728 inch diameter copperweld main messenger cable, one 250,000-circular-mil in termediate cable, and one 4 / 0 grooved copper contact wire, which had 65-per-cent conductivity. T h e new catenary construction between Gary and Michigan City was of the same type except t h a t the main messenger consisted of one 0.81-inch diameter copperweld cable and the intermediate messenger was 300,000-circular-mil cable. This larger design was necessary to increase the current-carrying capacity in this single track terri tory where only one ca tenary was involved. This construction used the rigid hanger between the main mes­senger and the intermediate cable for a good electrical connection. T h e contact wire was supported from the intermediate cable by means of flexible hangers.

This changing of the overhead ca tenary system as far east as Michigan City was completed abou t 1930. D m i n g this same period a 500,000-circular-mil feeder cable was installed on the pole line from Michigan Ci ty to South Bend. T h e old steel main messenger was still used. A 4 / 0 grooved contact wire was suspended from the old contact wire by means of duplex clips. This was to add sufiicient carrying capacity over this s t re tch of single t rack line. A feed t ap tied the feeder cable and the ca tenary system together abou t every fifth pole. Through all cities where the South Shore operates in city streets, i t was necessary to install a 7oO,000-circular-mil cable on the pole line. This larger feeder cable was necessary to fiu-nish sufiicient capacity through these locations due to the direct suspension type of construction. In this construction, the poles are located in t he parkway between the curbing and sidewalk on bo th sides of each street with a 3 /8 inch messenger wire cross spanning the distance between opposite poles. T h e contact wire is a t tached to the span wire by means of a trolley s teady device. A feed t ap also connected the feeder cable on the pole fine wi th the contact wire about every sixth span.

A section of t rack immediately east of Gary was rebuil t with Bates built-up galvanized overhead bridges. These towers were spaced a t 300-foot intervals over the mile and a half section of double track. The 0.72 main messenger was supported by means of a pin-type insula­tor a t t ached to the top of the bridge. T h e intermediate is suspended from the main messenger by means of hangers of various lengths the longest of which were 58 inches and located nearest the bridges. On the south side of these bridges, a riser section was located to support the 33,000-volt transmission line. This section became known as the "ideal section."

Wi th the change to the 1500-volt d-c

system, eight new substations were built along the right-of-way. These consisted of foiu* ro ta ry converter stat ions and four mercury-arc rectifier stations. These s tat ions were spaced approximately 10 miles apa r t along the line. T h e overhead system was separated in to eight sections with the section insulators being located a t the substat ions. In addition to these eight substations, a 1,500-volt feed was obtained from the IlHnois Central sub­stat ion a t Kensington to help feed the H a m m o n d to Kensington section.

T h e eight substat ions are owned and mainta ined by the Nor thern Indiana Pubfic Service Company. T h e South Shore purchases the current a t the various substat ion locations and is reponsible for all of the maintenance outside of the sub­stations. T h e Public Service Company feeds the substat ions with a 33,000-volt 3-phase pr imary line which is a t tached to crossarms located on rented pole space a t the top of the rai lroad's mas t arm pole lead.

T h e substat ions va ry in ou tpu t capac­i ty. One stat ion has a 750-kw output , while six other stat ions have 1500-kw out­put . The largest substation is a Brown-Boveri mercury-arc rectifier located a t Michigan City and i t has an ou tpu t capacity of 3,000 kw.

T h e substat ions are controlled by a carrier c turent supervisory superimposed on one land wire. This supervisory con­trol permits the automat ic opening and closing of any substat ion feeder by remote control from the railroad's dispatcher 's office. T h e Pubfic Service Company has the au tomat ic supervisory control over the substat ion rectifiers and ro tary con­verters in the same manner .

Under this program, the old semaphore signals were replaced with automatic block position color light signals. Use of impedance bonds a t the insulated joints which separated t rack circuits was neces­sary to permit the negative re turn of the propulsion current to flow unobstructed to the substations. These bonds halted

Figure 3. Three-car passenger train composed oi three modernized air-conditioned cars near Michigan City, showing typical curve catenary

construction Figure 4. One of the original 6,600-volt a-c passenger cars which

became obsolete with the rehabilitation program

M A Y 1 9 5 3 Jones—An Interurban Becomes a Railroad 1 0 1

Figure 5 (above). * O i d 1126 / * a 6,600-volt a-c passenger car after conversion to 1,500-volt d-c operation

Figure 7 (right). Original Hegewisch, I I I . , passenger station, showing overhead construction and semaphore-type signal employed during

6,600-volt a-c operation

the flow of the al ternat ing track current a t t h a t location for the signal system and per­mit ted the passage of the direct negative current. On double track main, the sig­nals were 3-position color lights and on single track, 2-position lights were used. The signals were spaced approximately 1 mile apar t . With the changeover, the majori ty of the centrifugal t rack relays were replaced with vane t rack relays.

Another circuit was added to the telephone system between Michigan City and IlHnois Sta te Line. This was a message circuit used for company business. Since the t rains were operat ing over the Illinois Central Railroad into Chicago, i t was necessary to extend the telephone circuit to Randolph Street. T h e dispatch wire and one company message circuit

were extended. T h e major portion of the Hght original

70# rail on the main line was replaced with 100# rail.

T h e first d-c equipment was delivered in June 1926. These cars were p u t in service between South Bend and Michigan City wi thout suspending operations. D-c operation was moved west as substat ions were finished.

Originally, 10 combination baggage and coach cars, 15 coaches, 2 parlor cars, 2 dining cars, and 10 trail cars

Figure 6. Over­head mainte­nance crew work­ing from insulated deck of line car on typical cater-nary construction

were purchased. Hourly service between Chicago and vSouth Bend, and half-hourly between Chicago and Gary was inst i tuted. This improved service be­tween Chicago and Gary resulted in an increase of 45 per cent of travel in the first 2 months of operation. The re-habiHtation brought astonishing results and i t was necessary to place an order for more equipment . In all, 69 pieces of passenger equipment were purchased. This equipment consisted of 50 motor cars, weighing 130,000 pounds and seating 56 passengers; 13 trail cars, weighing 99,000 pounds and seating 50 passengers; 4 parlor cars, and 2 diners. The cars were 60 feet long with all steel body and underframe and an insulated roof.

T h e electrical equipment on each car consisted of four Westinghouse type-567-C9 750-volt d-c 210-horsepower trac­tion motors with 24 to 59 gear rat io giving a maximum speed of 72 miles per hour. These motors were controlled by Westing­house type-HBF electropneumatic uni t switch control working on a 32-volt auxiliary circuit. A type-XM-160 con­troller was used, equipped with reverser handle and dead-man control. The con­trol was nonautomat ic and the controllers were located a t each end of every car in order to obtain a maximum of flexibility in t rain assembly. The controller had ten notches, five series, and five series-parallel positions, the last series-parallel

102 Jones—An Interurban Becomes a Railroad M A Y 1 9 5 3

Figure 8. Section of present caternary system consisting of one 0.81-composite 191-strand primary messenger cable, one 250,000-circular-mil 19-strand copper secondary messenger

cable, and two 4 / 0 grooved bronze trolley wire, 80-per-cent conductivity

l)usition giving short field connection for additional speed.

The switch group was comprised of 11 Westinghouse UP-602 switches for ac­celeration, transit ion, and field shunting, plus two UP-602 switches connected in series for line switches. The line switches opened simultaneously in case of overload, as well as when the master controller was returned to off position.

Current collection was provided by a spring-raised air-lowered double-shoe pantagraph and a trolley pole for auxiliary or emergency use; however, due to speed and 2-direction operation, the trolley pole was impractical and another pan tagraph was installed. Lightning protection was obtained by a type IC capacitor lightning arrester located on the car roof.

All the control circuits necessary for multiple operation were t rain lined through all the cars in two separate jumpers in order to keep the size to a minimum for easy handling. A 1,500-volt bus line from the motor cars furnished power for auxiliary circuits on all trail cars. The 1,500-volt bus hne receptacles were protected by contactors which were opened by switches on the angle cock of the air brake lines. T h e d rum- type re­verser was operated by an electropneu-matically controlled air engine.

Each motor and trail car was equipped with a Westinghouse YX-11 2V2 -kw 1,500-32-volt motor-generator set de­signed to give close regulation wi thout ex­ternal regulating devices. T h e generator was a compound machine with series field connected to carry ba t t e ry current . If the generator voltage would decrease, the ba t te ry discharged to the load through the series field, which, in turn, increased the generator excitation. This series field also acted differentially to prevent the ba t t e ry from charging a t too high a ra te .

Air was furnished by a Westinghouse Z)3 F 35-cubic-foot-per-minute compressor. The motor was a 10 horsepower 1,500-volt series type controlled by a type J

W'estinghouse air brake, electric compres­sor governor.

Headlights consisted of a 32-volt 250-w a t t lamp mounted in front of a circular reflector. All interior lighting and venti­la t ing fans were taken from t h e 32-volt ba t te ry .

Hea t was furnished by a Peter vSmith ha rd coal stove circulating hot water. Auxiliary electric hea t was furnished from strip heaters operat ing on 1,500 volts and controlled from a thermosta t mounted in­side the car.

In October 1929, the vSouth Shore Line won the Charles A. Coffin prize and the Electric Tract ion Speed Trophy . This was the first t ime in the history of the indust ry t h a t the same railroad had won both honors a t the same time. The Coffin award was presented for distinguished contr ibution to the development of electric railway t ranspor ta t ion for the convenience of the public and benefit of the industry . T h e Electric Tract ion Speed contest, won by this railroad in a field of 22 fast interurbans, classed the South Shore Line as the fastest electric railway in America. A goal was set to eventually make all through trains on a t least a 2-liour schedule. Westinghouse Engineers made an intensive s tudy of the traction motor speed characteristics and recommended increasing the air gap on the tract ion motor to give a higher balanc­ing speed. By increasing the air gap and improving physical properties, the speed was increased about 6 miles per hour.

Along with the rehabihta t ion of equip­men t for improved passenger service came the desire for increased freight service. Immediate ly new interchange connections were built with s team railroads, and by 1929 the South Shore Line had connections with 13 railroads.

In June 1926, four Westinghouse locomotives were pm-chased to give rapid overnight freight service which h a d been inaugurated. These locomotives weighed 80 tons and were powered by four

Westinghouse number 358, 750-volt 360-horsepower series motors, two connected permanent ly in series. A type-HBF--1/6^ double-end control was used, employ­ing a type number 337 W^estinghouse controller with nine steps in series and seven steps in series-parallel. The 1-hour rat ing is 30,400# tract ive effort in full Held with a speed of 17 miles per hoiu*. The over-all length of the engine is 39 feet 8 inches. A Westinghouse YX-11 ~A motor-generator set is used to charge a 32-volt ba t te ry . A type- YB-4 1,500-volt blower unit is used for cooling the traction motors . Air brakes are of the Westing­house 14 EL type.

In 1927 to meet the demands of rapidly increasing freight business, two Westing­house 53-ton switcher locomotives, avail­able for immediate shipment, were purchased to give additional motive l)ower unti l heavier locomotives were de­livered. These locomotives were powered by four 125-horsepower 750-volt number 562 Westinghouse series motors. A iype-HBF double-end control and UP-602 uni t switches were used. The gear rat io was 60 to 17 with a I-hour ra­ting of 15,200# full field, and speed of 12.5 miles per hour. The trucks were of Baldwin 4-wheel type equipped with 36-inch wheels. There were two type-Y4D Westinghouse blowers used for cooling traction motors . Brakes were furnished by Westinghouse air brake, type 14 EL.

Because of a further substantial in­crease in freight business and the neces­sity of fast overnight service, four more 80-ton Westinghouse-Baldwin locomotives were purchased in 1928. In 1930 one more 80-ton Westinghouse locomotive and three General Electric locomotives of the same design and size were purchased. T h e electrical design was similar so tha t multiple-unit operation was possible be­tween all 80-ton W^estinghouse and General Electric locomotives.

After the panic of 1929, improvements were curtailed except where a substantial saving in maintenance was realized. In 1931 all parlor and diners were taken out of service. No major changes were made on the railroad until 1937.

When the railroad began its modern­ization program in 1937, a second contact wire was installed along side of the first one. This was also a 4 /0 grooved cop])er wire. In 1942 the job of replacing the old steel main messenger east of Michigan Ci ty was begun. Again, due to single track main hne, 0.81-copperweld cable was used as the main messenger, 300,000-circular-mil cable was used as the inter­mediate messenger, and two 4 /0 grooved copper contact wires were installed.

M A Y 1 9 5 3 Jones—An Interurban Becomes a Railroad 103

In 1947 the raih-oad began replacing poles in the telephone signal lead, located on the opposite side of the t rack from the mast a rm poles in single t rac t terri tory, with poles of sufficient height to permit the a t taching of a Bates expanded steel truss between the m a s t a rm pole and the telephone-signal pole. This type of construction has been installed on alter­na te poles extending east from the Ideal Section to Michigan City, a distance of 15 miles. The trusses not only provided a more flexible method of aligning and ad­just ing the catenary system, as the catenary is suspended from an insulator which is a t t ached by means of a beam clamp to the bo t tom side of the beam, bu t i t s trengthens bo th the m a s t a rm pole lead and the telephone-signal pole lead diuing high wind and heavy sleet and ice conditions.

In 1940 a portable substat ion was buil t to supplement the eight existing ones already in use. This was a ro ta ry converter- type stat ion and was mounted on two railroad cars. One car supported the converter and i ts auxiliaries and the other was the transformer car. I t was normally located on a siding just west of Gary, which placed it in the middle of the heavy traffic and switching area. This station was also moved a t various t imes to the site of one of the fixed stat ions and was p u t on the line a t the required location so t h a t the fixed stat ion could be removed from service for an indefinite period to permit extensive overhauling and checking to be carried out.

The majori ty of the work on the catenary system is performed from the top deck of a mult iple-unit line car especially buil t in the company shops for this work. This car has a completely insulated top deck and a portable deck, with a hydraul ic hoist mounted a top the insulated deck. This movable deck facilitates the maneuverabi l i ty t h a t is required in maintaining an overhead catenary system and a wooden pole line.

I n 1945 the railroad began eliminating the 2-position color light signals t h a t were in use on single t rack main, and replaced them with the 3-position color fight sig­nals, t hus making the signal system the same over the entire line.

Wi th the rapid increase of automot ive traffic, a s trong effort was m a d e to eliminate or adequately protect all dangerous highway grade crossings. This was accomplished by installing either automat ic crossing gates or au to­mat ic flashing lights or both .

The installation of a 2-way space radio system was s tar ted in 1947. This system consisted of one main station in Michigan

City and two repeater relay stations, one located 22 miles east of Michigan City and the other 32 miles west. Wi th the use of dual remote control stat ions—one in the Chief Dispatcher 's office and one a t the switchboard operator 's position, bo th located in the general offices a t Michigan Ci ty—and the repeater relay stations any mobile uni t on the railroad right-of-way between South Bend and Kensington can be contacted immediately. Present in­stallations include 11 freight locomotives, 12 motor vehicles, including supervisory automobiles, and signal and fine mainte­nance trucks. Four teen portable handie-talkie radios have been installed in the rai lroad's cabooses so t h a t end-to-end communication between engine and ca­boose can be maintained.

During this modernization period, the 100# rail is gradually being replaced by 115# rail. Pressm-e welded rail has re­placed the conventional jointed rail on some sections of the railroad. T h e main line has been entirely reballasted with crushed limestone.

T h e first t rend toward modernization of cars was the installation of new seats in ten coaches and paint ing the interior of the cars with light colored paints to help a t t r ac t passenger business. In 1939 mechanical- type water coolers were in­stalled in the passenger cars using a reciprocating compressor driven by a 32-volt motor from the ba t te ry .

All t ract ion motor bearings and journal bearings were of the sleeve type. As a result, a great number of the road failures were due to ho t bearings. One of the big improvements toward reduced mainte­nance was the changeover to roller bear­ings. In 1940, this program was s tar ted which eliminated all ho t bearings on the t ract ion motors and journals.

In 1941 passenger business h a d in­creased tremendously and it became neces­sary to obtain more seating capacity. I t was impossible to purchase new equip­men t because of the war effort, so it be­came necessary to concentrate on in­creasing the seating capacity of the equip­m e n t on hand . A proposition was sub­mi t ted to the Pul lman Company for lengthening the cars. A design was worked out to cut the cars a t approxi­mate ly the center and add a 17-foot 6-inch section which would increase the length of the cars to 77 feet 6 inches and increase the seating capacity from 56 to 80 pas­sengers. Because the Pul lman Company could do the job only in 10-car lots, this program of modernization was under­taken in the South Shore shops, as this number of cars could not be removed from service a t one time.

Several improvements were made to bring this equipment up to present-day s tandards . Fluorescent fighting was in­stalled using a 32-volt motor driving a 110-volt a l ternator made by the Safety Car Heat ing and Lighting Company. Forced ventilation was installed using an overhead blower for puffing in outside ak and recirculating t he air in the car. Mechanical air conditioning was to have been installed b u t a t t h a t t ime a 1,500-volt motor of the proper size was not available. Keep pace with modem trends of passenger comfort, the subject of air conditioning was again consid­ered in 1945. Because a 1,500-volt motor of the proper size still was not avail­able, Waukesha equipment was selected. This equipment consisted of a 20-horse-power 4-cyfinder propane engine driving a 7-ton reciprocating-type compressor. T h e evaporator and ventilating fan con­sisted of a Trane upright uni t located in a compar tment a t one end of the car. To give bet ter hea t regulation in air-con­ditioned cars, an automatic-fired thermo­statically controlled oil heater was in­stalled. Ho t water was circulated by a pump through finned radiation located the fufi length of each side of the car. Other improvements made in these cars were the instafiation of double-glazed picture-type windows and part i t ions for smoking and no-smoking compartments.

Due to the additional 32-volt load on the lengthened cars, larger motor-genera­tor sets are now being installed. These sets are a General Electric GMG-150 ra ted a t 5 kw. Also, sealed-beam head­lights are being installed on all of the passenger equipment using two, 200-watt sealed-beam lamps enclosed in a Mars-type case.

By 1950 30 coaches and six trail cars had been lengthened. Eighteen of these 30 coaches were equipped with mechanical air conditioning and oil heat and the seat­ing capacity increased by 36 per cent.

In 1941 when freight business was on the upswing, additional freight motive power, geared for speed, was found neces­sary. As a result, the two 50-ton loco­motives were sold in favor of the four 100-ton Westinghouse-Baldwin locomo­tives purchased from the Illinois Central Railroad. These locomotives are powered by four number 360-type 750-volt 365-horsepower series motors. A type-HBF-MU double-end control is used with 11 steps in each position; inductive shunt­ing is used for higher speed. The 1-hour rat ing is 31,000 tract ive effort in fufi field a t a speed of 17.7 miles per hour. The over-all length of the engine is 40 feet, 1 inch.

1 0 4 Jones—An Interurban Becomes a Railroad M A Y 1 9 5 3

Two type-ΥΧ-9A 3 blowers are used for cooling traction motors , each driving a 32-volt generator for ba t t e ry charging. As the blowers are in continuous operation when the locomotive is in service, a volt­age regulator prevents the ba t t e ry from becoming overcharged. Air brakes are of the New York Air Brake Company type ESWL-LT.

Additional freight mot ive power was discussed in 1947, b u t to have a company build only a couple of locomotives was" very e'xpensive. Some preliminary s tudy and designs were m a d e for building a locomotive in t he shops on the p roper ty ; however, this idea was cast aside in 1949 when 20 General Electric locomotives became available. These locomotives were built for Russia on a lend-lease order but before the completion of the order, the United S ta tes S t a t e D e p a r t m e n t s topped shipment. T h e South Shore purchased three of these locomotives. As the loco­motives were designed for 3,300-volt d-c operation, i t became necessary to convert the electrical phase for 1,500 volts direct

c turent . Wi th some assistance from General Electric engineers, this conver­sion was m a d e in the rai lroad company 's shops.

These locomotives employ eight Gen­eral Electric 7 5 0 - 1 , 5 0 0 - v o l t motors . T h e 1-hour ra t ing is 5 ,500 horsepower with a t ract ive effort of 8 5 , 5 0 0 # in full field a t 2 5 miles per hour. Acceleration is nonauto­mat ic with electropneumatic contactors, series-parallel switch; and electropneu­mat ic operation is arranged to give 16 steps in series, 10 steps in series-parallel, and 11 steps in parallel plus two reduced field steps in each motor combination.

There are two motor-generator blower sets consisting of a 1,500-volt motor , 5 0 -volt generator and blower mounted on a common shaft. T h e generator is under regulator control for Hghting, control, and ba t t e ry charging. Two 150-cubic-foot-per-minute 2-stage air compressors fur­nish air for air brakes and electropneu­mat ic control operating a t 5 0 volts, one compressor operating from each of the two motor-generator sets. T h e locomotives

were originally equipped with regener­a t ive braking, b u t because the South Shore h a d no use for electric braking and because i t furnished several contactors necessary for conversion, this featiure was no t used.

T h e locomotives are 8 8 feet 10 inches long with a to ta l weight of 545,600 pounds and a weight of 405,600 pounds on the drivers. T h e locomotives, being of road-type construction, are designed to nego­t ia te a ciu-ve of 360 foot radius or 16-degree minimtrm.

T h e modernization program on the South Shore is still in full swing. The railroad, by employing the latest available equipment in the electrical and com­munications fields, has endeavored to present to the public a rapid and efficient means of pubHc transportat ion service.

T h e transformation from an interurban to a railroad has been a successful one and the South Shore's futiu-e in tent is to keep abreast with the t rend of time, always keeping public safety and convenience as the prime goal.

No Discussion

Dynamic Braking on Diesel-Electric

Locomotives

A. V. JOHANSSON H. R. STIGER MEMBER AIEE ASSOCIATE MEMBER AIEE

Synopsis: The increasing prominence of the diesel-electric locomotive on American railroads has given new impetus to the use of dynamic braking. Originally in­tended as a means of controlling both passenger and freight train speed on moun­tain grades, it has been refined to the point where it is increasingly used for controlling freight train speed in relatively level terri­tory. A recent refinement of braking con­trol takes advantage of additional traction motor capacity available a t lower speeds. Extensive service tests have demonstrated the operational and economic value of this form of braking.

ON E O F the great advantages of the diesel-electric locomotive over s team

motive power is i ts ability t o provide dynamic braking. When operat ing in dynamic braking, the tract ion generator is used to excite the fields of the t ract ion motors, see Figure 2. T h e motors t hen act as separately excited generators, driven by the motion of the train, and

produce a voltage. When resistors are connected across the motor armatures , this voltage causes current to flow and load the motors . As a resul t they pro­duce a torque which opposes the torque produced by the wheels.

T h e advantages of dynamic braking are greatest in mounta inous terr i tory, b u t i t has also been found valuable on railroads not having heavy grades. In such cases the dynamic brake provides a quick, easy means of applying re tarding force to the t ra in when its speed mus t be restricted, and for bringing i t almost to a hal t when a stop mus t be made . T h e la t te r is of part icular advantage for freight t rains. As a rule t he reduction of brak­ing effort as the speed decreases makes the braking r a t e too low for passenger t ra ins .

There is nothing part icularly new about the basic idea of dynamic braking. I t is a simpler form of the regenerat ive brak­ing used on electrified roads years be­

fore the diesel-electric locomotive came into being. T h e pr ime difference be­tween dynamic and regenerative braking lies in the method used to dissipate the power produced. Dynamic braking uses a resistor built into the locomotive for this purpose. Regenerative braking em­ploys t he railroad power system to take the energy from the t ra in and use i t else­where or dissipate i t in resistors a t the substat ion.

Dynamic Braking Limitations

During dynamic braking the diesel engine is normally operating a t idle speed. This reduces t he ventilation to the t rac­t ion motors, and consequently their rat ing. Therefore, i t often becomes necessary to increase the motor ventila­t ion over wha t i t is with the engine idling. Various methods are used, depending on whether the tract ion blowers are me­chanically or electrically driven. T h e amount of ventilation required depends

P a p e r 53-48, r e c o m m e n d e d b y t h e A I E E L a n d T r a n s p o r t a t i o n C o m m i t t e e a n d a p p r o v e d b y t h e A I E E C o m m i t t e e on Techn ica l Ope ra t i ons for p r e s e n t a t i o n a t t h e A I E E W i n t e r Gene ra l M e e t i n g , N e w Y o r k , N . Y. , J a n u a r y 1 9 - 2 3 , 1953. M a n u ­scr ip t s u b m i t t e d Oc tobe r 20, 1952; m a d e avai lab le for p r i n t i n g N o v e m b e r 19, 1952.

A. v. J O H A N S S O N a n d H . R . S T I G E R a re wi th t h e Genera l E lec t r i c C o m p a n y , Er i e , P a .

M A Y 1 9 5 3 Johansson, Stiger—Dynamic Braking on Diesel-Electric Locomotives 1 0 5