British Rail Class 73

The British Rail Class 73 is a class of 49 electro-diesel locomotives that can run on the Southern Region's 650/750 V DC third rail supply or on a small onboard diesel engine, which made them versatile on lines without electrification even though the diesel gives far less power than the third rail. The first six, a prototype batch with 1,600 hp on electric power and an English Electric 600 hp diesel, were built by British Rail at Eastleigh Carriage and Wagon Works and introduced during 1962. A production batch of 43 followed from English Electric at the Vulcan Foundry between 1965 and 1967. It is one of the first bi-mode locomotives ever built, and many are still in service after a life of more than 64 years.