British Rail DP1

The English Electric DP1, known as Deltic, was a prototype diesel-electric demonstrator locomotive built by English Electric at its Dick, Kerr works in Preston in 1955. It carried two 18-cylinder Napier Deltic engines, each derated from the 1,750 horsepower of the marine version to 1,650 horsepower, for 3,300 horsepower in all. The project was officially numbered DP1 and its internal title was Enterprise. After trials in 1955 on the London Midland Region of British Railways it worked passenger trains between London and Liverpool and London and Carlisle, and its high power at a low axle load led British Railways to order 22 production locomotives that became the Class 55. DP1 was withdrawn in 1961 after an oil leak, given to the Science Museum in 1963 and later moved to the National Railway Museum.