This dual-power configuration allows a single train to run across both electrified and unelectrified territory without swapping engines. While under the wire or third rail, the unit operates as a straight electric locomotive, drawing external power to turn the traction motors. When the electrified territory ends, the engineer fires up the onboard diesel prime mover to generate electricity for those same motors.
Make sure the prime mover actually fires up before we hit the gap, or this bi-mode is just going to be dead weight.
Switching power modes on the fly requires specific throttle sequences, and blowing the transition will trip the breakers and stall the train.
Also heard as
- dual-mode
- electro-diesel
Related terms
Electric locomotive
A locomotive that draws its propulsion power from an external electrical source.
Diesel locomotive
A motive power unit that uses a diesel engine to generate electricity for electric traction motors.
Pantograph
A roof-mounted apparatus that collects electrical power from an overhead contact wire.
Third rail
An electrified rail running parallel to the tracks that supplies power to trains.