The British Rail Class 03 locomotive was, together with the similar Class 04, one of British Rail's most successful 0-6-0 diesel-mechanical shunters. The class, numbering 230 examples, was built by British Railways' Swindon and Doncaster works in 1957-1962 and numbered D2000-D2199 and D2370-D2399 (later 03004 to 03399). D2370 and D2371 were used as departmental locomotives and originally numbered 91 and 92 respectively.