The Silverliner IV is an electric railcar designed and built by General Electric. This was the fourth generation railcar in the Silverliner family of single level EMUs and it is currently used by Philadelphia's SEPTA Regional Rail. The 232 car order of Silverliner IV cars, delivered between 1973 and 1976, represented the largest order of the Silverliner series to date and allowed for the retirement of most of the Reading 'Blueliner' and PRR MP54 MU cars, dating from at least the 1930s, that were still running on their respective Reading and Pennsylvania Railroad systems. Three times the size of the previous Silverliner orders put together, the Silverliner IVs became SEPTA's standard passenger rail vehicle from 1976 on. Like the Silverliner IIs and IIIs before them, the IVs were owned by SEPTA and provided to the private railroads for use in their state supported commuter rail operations until SEPTA took over direct operation in 1983. From Wikipedia
