The passenger locomotives derivatives of the General Motors EMD GP40 diesel-electric locomotive have been, and continue to be, used by multiple passenger railroads in North America. For passenger service, the locomotives required extra components for providing steam or head-end power (HEP) for heating, lighting and electricity in passenger cars. Most of these passenger locomotives were rebuilt from older freight locomotives, while some were built as brand new models.

The EMD GP40 is a 4-axle diesel-electric locomotive built by General Motors' Electro-Motive Division between November 1965 and December 1971. It has an EMD 645E3 16-cylinder engine generating 3,000 hp (2,240 kW).