SEPTA operates a 25 Hz traction power system in the vicinity of Philadelphia, Pennsylvania, that it inherited from the Reading Electrical substation components pdf. This system is separate but similar to the system designed by the Pennsylvania Railroad, which is now operated by Amtrak.
SEPTA’s trains can run over either system because the voltage and frequency presented to the locomotive are essentially identical. However, the ex-Reading system is not electrically connected to the ex-PRR system. SEPTA owns all of the substations described herein. Elwyn Line and the Chestnut Hill West Line, as well as a new substation just north of 30th Street Station, those facilities are electrically part of Amtrak’s 25 Hz traction power system.
Electrification power infrastructure at Lansdale, PA. The Reading Railroad electrified its lines between Reading Terminal in Philadelphia, PA and Norristown, Doylestown, Chestnut Hill, Hatboro and West Trenton in 1931. The electrification was extended to include the Fox Chase Line in September 1966. Electrification was again extended from Hatboro to Warminster in the early 1970s.
Pennsylvania Railroad’s 1915 initial electrification and 1930s mainline expansion. Unlike the PRR’s system, which included multiple power sources and an extensive high-voltage transmission network, the Reading’s electrification was supplied solely by the rotary converter station at Wayne Junction. Although ownership and operation of the system has changed, the system has remained essentially unchanged with the exception of the replacement of the rotary converter station at Wayne Junction with a solid-state cycloconverter in 1986. The Reading electrification system was designed for suburban MU operations and did not have to support the main line passenger or through freight operations of the rival Pennsylvania Railroad.
Most of the rail lines would carry one or two feeders attached to the top of the catenary support masts. A simple schematic of the Reading autotransformer distribution scheme. Most branches are short enough to only require a single substation near the end of the line, but the Main and West Trenton lines are long enough to require intermediate substations.