DP2, meaning Development Prototype number 2, was a prototype Type 4 mainline diesel locomotive, built by English Electric in 1962. The engine and electronic systems trialled in DP2 formed the basis for the later , for which it was effectively the prototype. Externally DP2 was visually similar to a Class 55 "Deltic" locomotive, as it used a modified Deltic bodyshell, but internally it had a single engine of a different type to the twin-engined Deltics. DP2 was used firstly in trials, and then in ordinary service until 1967, when it was wrecked in a serious accident at Thirsk. History Design The locomotive was built in 1962 by English Electric at their Vulcan Foundry in Newton-le-Willows to demonstrate its wares to British Railways. As the Deltics were then in production, it was decided to produce the locomotive on the same production line; the bodyshell used for DP2 reputedly being the eighteenth made. While DP2 looked like a Deltic in outline, there were many detail differences; particularly the large bodyside radiator vents at one end, and the single roof fan as opposed to the four symmetrically placed fans on the Deltics. These differences revealed that DP2 was totally different from the twin-engined Deltics internally, having only a single prime mover and generator. The loco was later updated with electronic control systems to become the forerunner of the Class 50. It was of Co-Co wheel arrangement and was fitted with an English Electric 16CSVT engine of . It had a maximum speed of and weighed . It was initially painted in standard BR Brunswick Green livery and later (from 1965) in two-tone green livery with a light green lower bodyside band. Operation Its first test service was on 2 May 1962, running light from Newton-le-Willows to Chester and back. Its final test with Vulcan Foundry was a fast running test six days later, with a 15-coach train of between Crewe and Penrith, passing Tebay at . On 11 May, the locomotive was lent to the London Midland Region for crew training where it undertook a few Crewe–Birmingham runs. From 14 May 1962, BR tested it on regular London Midland Region services out of London Euston and later on the Eastern Region from London King's Cross. Following its first major overhaul in mid-1965 and clad in new two-tone green Deltic livery, it was used on the Sheffield Pullman workings until 1966. It was fitted