Pennsylvania Railroad class E2c comprised a pair of experimental C-C (AAR) or Co-Co (UIC) electric locomotives.

The bodywork and running gear was produced by Baldwin-Lima-Hamilton while the electrical equipment was provided by Westinghouse,[2] who also acted as principal contractor.

[2] The significant technical difference between the locomotives was that those from General Electric used traditional AC traction motors.

Those by Westinghouse had mercury arc rectifiers to convert the AC traction power to DC.

In consequence they were able to use ordinary DC traction motors, identical to those on contemporary diesel-electric locomotives.