Further information from J Thickitt.
This was a Brush Type 4, built by Brush Traction company at Loughborough, one of the first generation of diesel locomotives.
Diesel locomotive D 1504. Until the diesel fleet was re-numbered around 1973 the 'Type' number was a code showing the power rating of a class. On all but one route Type 4s, of which there were several designs, were the most powerful British Railways diesels.
D1504 is seen here in the early British railways two-tone green livery. |