The British Rail Class 71 was an electric locomotive used on the Southern Region of British Railways. Unlike Southern Region electro-diesel locomotives they could not operate away from the electrified system.
E5001 at Doncaster Works.
Electro-diesel locomotive
An electro-diesel locomotive is a type of locomotive that can be powered either from an electricity supply or by using the onboard diesel engine. For the most part, these locomotives are built to serve regional, niche markets with a very specific purpose.
OPE1A [ru; uk] industrial electro-diesel locomotive for quarry railways with primary electric locomotive and two diesel B–units
British Rail Class 73, no. E6013 (73107) at Rowsley South, on the Peak Railway on 17 April 2003. This locomotive was on loan from Fragonset Railways, and has since returned to main-line service with RT Rail.
DM30AC 501 primarily diesel locomotive operating in electric locomotive mode from a third rail at New Hyde Park, USA
Stadler Euro Dual 2159, no 219, at Dresden railway station, Germany