A British Rail 6 Wheel Coach converted and used as a power source, a Generator Coach is an innovative and curious device serving in a capacity far different from the typical expectation of a coach simply to carry. While British Rail's standardised coaches with their simple and direct marks have dominated the InterCity lines for decades, many different services are provided including the typical purposes of coaches and railway transport.

In lines where a pantograph was not freely available to power electric trains, a power outage appears unexpectedly or even a hotel or other building required electricity; the Generator Coach was an emergency tool at hand.