Deltic Prototypes

English Electric gave two prototypes to BR, with the Napier Deltic Engines which went into the Class 23 and Class 55.

DP1
English Electric DP1, commonly known as Deltic, was a prototype 3,300 hp (2,500 kW) demonstrator locomotive employing two Napier Deltic engines, built by English Electric in 1955.

The high power of the locomotive at an acceptably low axleload resulted in 22 similar locomotives being ordered by British Railways for use on East Coast Main Line express passenger services; the serial production of which became the  Class 55.

DP1 was initaly preserved by the Science Museum, but in October 1993 it was moved to the National Railway Museum.

DP2
The DP2 was the second Deltic Prototype sent to British Rail, but unlike DP1, it was scrapped.

On 31 July 1967 it was involved in a serious accident at Thirsk, colliding at speed with the de-railed Cliffe to Uddingston cement train. DP2 sustained severe front and left hand side damage, and was taken to York shed where it remained sheeted over. The damage proved to be so great that it was considered uneconomical to repair. It was withdrawn from BR service in September 1967 and moved to the Vulcan Foundry where it was stored until it was dismantled in 1968, its reusable parts being provided to the Class 50 pool of spares. Its engine initially went to D417/50 017 'Royal Oak', but ended its working days in 50 037.