British Rail Class 73
 The British Rail Class 73 is a United Kingdom model of electro-diesel locomotive. The type is unusual in that it can operate from the Southern Region's 650/750 V DC third-rail or an on-board diesel engine to allow it to operate on non-electrified routes. This makes it very versatile although the diesel engine produces less power than is available from the third-rail supply so the locomotives rarely stray from the former Southern Region of British Rail.