The GE E60 is a family of six-axle 6,000 hp (4.5 MW) C-C electric locomotives made by GE Transportation Systems (GE) between 1972 and 1983. The E60s were produced in several variants for both freight and passenger use in the United States and Mexico. GE designed the locomotive for use on the Black Mesa and Lake Powell Railroad (BM&LP), a dedicated coal-hauling route in Arizona, which began operation in 1973. That same year GE adapted the design for high-speed passenger service on Amtrak's Northeast Corridor. The largest customer was Ferrocarriles Nacionales de México (NdeM), the state-owned railroad in Mexico, which bought 39 for a new electrification project in the early 1980s.

The EMD AEM-7 is a twin-cab four-axle 7,000 hp (5.2 MW) B-B electric locomotive built by Electro-Motive Division (EMD) and ASEA between 1978 and 1988. The locomotive is a derivative of the Swedish SJ Rc4 designed for passenger service in the United States. The primary customer was Amtrak, which bought 54 for use on the Northeast Corridor and Keystone Corridor. Two commuter operators, MARC and SEPTA, also purchased locomotives, for a total of 65.