1 1* w. HUH * Street Railway Journal. FoZ. XTF. .7Vi?IF ^JVD CHICAGO, JANUARY, 1898. No. 1. STORAGE BATTERIES AS STATION AUXILIARIES IN PITTSBURGH ' i, Just before the first of the recent important consolida- iug June, 1896. Fig. 3 gives an outline map of the cities of tions of street railway interests in the city of Pittsburgh, Pittsburgh and Allegheny with the location of the present which began by the organization of the Consolidated Trac- four power stations and of the two accumulator plants of tion Company in July, 1895, there were some thirteen in- this company. One of these, as will be seen, is at the dependent systems, most of which were operated from Oakland station on the corner of Fifth Avenue and their own power stations. Since that time there have been Atwood Street, while the other is about midway between many extensions and improvements and some 30 miles of the other three stations. track has been changed from cable to electric traction. At The rated output of the four generator stations, not present there are in the street railway system of Pittsburgh including the batteries, is about as follows : and inclined miles Allegheny, exclusive of the planes, 307 Allegheny station 1300 k. w. of track, all electric, while the number of companies has Ben Venue station 2800 " " been reduced to nine. Of these the four most important Forty-seventh street station ... 500 " are the Consolidated Traction Company, United Traction Oakland station 800 Company, Pittsburgh & Birmingham Traction Company The two battery plants have each a capacity of 500 and Pittsburgh & West End Passenger Railway Company, ampere hours. Upon the completion of the consolidations already re- The type of storage battery used is that manufactured ferred to, the Consolidated Traction Company found itself by the Electric Storage Battery Company for use in most with seven power stations of which three were electric and of its installations, and consists of what is known as the four were cable, and the United Traction Company with " Manchester " positive plate and the " chloride" negative. four electric power stations. The stations of both of these The Manchester positive, which is a Plante positive, con- companies had been built, of course, to serve the needs of sists of a hard autimonious lead grid, with circular holes, separate sections of independent track so that after the about 7/& in. diameter. Into these holes are forced by hy- several lines had become united the first problem be- draulic pressure, coils of corrugated lead tape, which are came that of the proper rearrangement of the power gen- machine made from the purest lead. This plate is formed eration for the most economical operation of the respective electro-chemically, and the great surface of the corrugated roads. This preliminary statement is necessary to a proper coils receives a Plante formation, while the autimonious understanding of the subsequent steps taken by the mana- lead grid is unattacked by the process. For the initial gers of the two traction companies in altering their sys- formation, only from 3 per cent to 5 per cent of the lead tem of power production, one of the results of which has ribbon is formed into a peroxide; the balance of it is avail- been the adoption of storage batteries as station auxiliaries. able for further formations in the regular working of the In this the Consolidated Traction Company was the battery, so that the life of the plate is very long. This pioneer, its accumulator plants having been installed dur- can be understood from the fact that this initial formation 2 STREET RAILWAY JOURNAL. [Vol.. XIV. No. i. is held in the plate very much more firmly and securely, iug, with zero point in the center of the dial. It gives the and with far less danger of falling out than was the active flow of current in each direction, and during most of the material in any of the old pasted forms of plates, which, day the indicator oscillates from one side of the scale to after they had lost their active material, or a portion of it, the other with the variation in load on the external circuit. also lost their capacity, while in the present form of The second storage battery station, which is at the "positive" the ribbon contains sufficient material that corner of Thirty-fourth Street and Penn Avenue, also occupies an old cable power station, which, however, does not contain any generating apparatus. The cells are also placed in the old tension room, and are connected to a iTth.St. Power Station I Ben-Venue Power Station Oakland Power Station d Storage Batteries Street Ry. Journal FIG. 3. -DIAGRAM SHOWING LOCATION OF STATIONS- CONSOLIDATED TRACTION CO. FIG. 2.- -DIAGRAM OF SWITCHBOARD CONNECTIONS AT 34TH STREET STATION switchboard, the bus bars of which are fed directly from the three other power stations of the company, as shown can form into peroxide before breaking up, of from ten to in Fig. 2. As will be seen, the power stations are thus fifteen times the extent of its initial formation. The connected directly to each other by feeders, as well as by negative plate is a regular chloride negative, which has the trolley circuit, a condition which while not impossible been found much superior to any other form of negative were no storage batteries in use, yet would require some plate- The process of manufacture produces a negative care to prevent the reversal of some of the generators at a active material, which is of a perfectly porous crystalline low potential station, and their operation as motors by the structure, with the axes of the crystals perpendicular to generators at the other stations. The batteries act as res- the surface of the plate. The charge and discharge rate ervoirs and regulators, somewhat in the same way as stand- of this type of cell is very high, as compared with the pipes in pumping stations act, to keep the pressure on the older " pasted" form, the batteries being regularly rated pumping engines constant. The switchboard connections to discharge their entire capacity in one hour's time, if at the Thirty-fourth Street station are given in Fig. 2, needed. which shows six panels, three of which are feeder The cells are connected in series, and at present 252 connections with other stations, one is a battery panel are in use at the Oakland station, and 244 at the Thirty- and the other two are ordinary line feeder panels. The first four are equipped with dif- ferential reading ammeters, and the Pleasant line feeders with straight reading am- Station meters. The quantity of charge in the battery can be readily determined by taking the specific gravity of the elec- trolyte in the cells by means of a hy- drometer made for the purpose. The specific gravity of the cells rises with the storage of current, and in actual operation varies in readings on the scale from 11 50—which indicates a low charge—to 1200, which shows a high charge. The individual voltage of the cells can also be determined on the switchboard by a special voltmeter, FIG. 4. — DIAGRAM SHOWING LOCATION OF STATIONS— UNITED TRACTION CO which can be connected to the termi- nals of ten of the cells, thus giving an fourth Street station. The number to be placed in series idea of the condition of the other cells. In this con- is varied according to the voltage which the engineers wish nection it may be stated that the engineers of the to obtain at the different points. The Oakland station is company report that the maintenance of these bat- an old cable station, and the batteries occupy the place teries has been, as yet, nil. As they are not built formerly devoted to the tension run. The old cable engines for transportation on cars, they are substantial and are still in use. They are two in number, each driving one contain plenty of lead; no buckling, or that old evil of end of a shaft, but the main driving drums on this shaft storage batteries, the falling out of active material, is pos- have been replaced by an 800 k. w. generator, which is sible with them, and the only attention required by them thus directly driven. The battery of 252 cells is con- during the six months during which they have been in op- nected in parallel across the bus bars, as would be the case eration has been the addition at occasional intervals of a with another generator, and are controlled directly on the small amount of distilled water to replace that lost by switchboard by a separate generator panel, with circuit evaporation. • breaker, ammeter, voltmeter and quick-break switch. The The flexibility in the manipulation of the power ammeter is not of the ordinary type, but differential read- stations secured by the use of storage batteries is remark- January, 1898.] STREET RAILWAY JOURNAL. able. The engineers can adjust the total load between the company's system are somewhat different from those on different power stations as desired by changing the volt- that of the Consolidated Traction Company, just dis- age. Thus, if any one station were carrying less load in cussed. The company has four stations, as follows: proportion to its capacity than the other stations, the engi- Station. Units. Capacitv. neers at that station would cut out some field resistance, Pleasant Valley . 10 990 k. w. raising the voltage at that station, and throwing on it Juniata Street 3 1,100 " " more of the mutual load, while relieving the other stations.