The Philadelphia Rapid Transit Company’s principal power station is at Delaware Avenue. Steam turbine generating equipment totalling 58,000 kw. is in service in three stations and is designed for 13,200 volts 3-phase 25 cycles at which it is transmitted to the substations. One or two direct-current stations are still available for supplying 600 volts direct to the trolley. Power is also purchased from the Philadelphia Electric Co. and the Philadelphia Hydro-Electric Co. _Substations_ The company operates a total of 17 substations used for supplying both surface and rapid transit lines. These stations contain a total of 65 units aggregating 103,500 kw. Power is distributed to all lines at 600 volts and on the rapid transit lines is collected from an under running third rail similar to that used on the New York Central Electric Zone. _Rolling Stock_ The rolling stock used on the Elevated-Subway line includes 215 motor cars each equipped with two motors. Trains are made up of all motor cars, no trailers being used. General Electric motors are used throughout including GE-66 and GE-222. The Frankford extension will be operated with 100 motor cars each equipped with two GE-259 motors. [Illustration: INTERIOR OF SUBSTATION AT 15TH AND TUCKER STREETS, SHOWING 2000-KW. SYNCHRONOUS CONVERTERS] ------------------------------------------------------------------------ GENERAL ELECTRIC COMPANY EQUIPMENT IN MULTIPLE-UNIT SUBWAY & ELEVATED SERVICE