the british rail class 03 locomotive is, together with class 04, one of br's most successful smaller 0-6-0 diesel-mechanical shunters. there are 230 members of the class and it was built by british railways' swindon and doncaster works in 1957-1962. they are 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.