FAMOUS FOUR: THE 1960s DIESEL PROTOTYPES
English Electric DP2
It may have looked like a Deltic, but it had the 16-cylinder heart of what would later become Class 50. English Electric’s Diesel Prototype 2 (DP2) was regarded as the most successful of the three ‘second generation’ Type 4 demonstrators tested by BR from 1961/62. Even after the decision to build hundreds of Brush Type 4s (Class 47s), the locomotive was retained by British Railways and worked alongside the Eastern Region’s Deltic fleet until it was written off in a collision in July 1967. By that stage, BR had already asked English Electric to supply 50 locomotives developed from the DP2 concept to help accelerate West Coast Main Line Anglo-Scottish expresses prior to electrification.
Dissatisfied with its first generation of Type 4 (2,000hp+) diesel locomotives, BR made it known in the early-1960s that it was looking for more powerful mixed traffic machines of around 2,700hp. These would allow it to accelerate and/ or increase the weight of passenger and freight trains to make them more efficient.
Faced with the prospect of a lucrative order for several hundred locomotives, Britain’s locomotive builders were keen to show that they could deliver a machine that met BR’s specification.
Three privately-built prototype main line locomotives were built by English Electric, Brush and BRCW/AEI, but Brush was also building a batch of 20 Type 4 Co-Cos developed from the
