31120 and originally Diesel 5538, was a diesel owned by British Railways.
31120 was built by Brush Traction on 2nd July, 1959, and originally carried the number 5538. He/she was later present to take Gordon's passengers at Barrow-in-Furness in 1986, after his fiery experience when a puncture dampened Gordon's fire and narrowly avoided overheating. 31120 was later retired from service on 27th September 1991, and scrapped on 7th June, 1994.
31120 is based on a BR Class 31, hence his/her number. D701 is another member of this class. Around 26 locomotives had been purchased and preserved for use on many heritage railways around the UK.
31120 was painted in the British Railways' Rail Blue with yellow warning panels but later was painted in Railfreight Grey with yellow cabs in his/her working life.
- 31120's headcode is "1X01". However, the "X" indicates "Royal Train" or "out-of-gauge load".
- Over 263 members of this class were built from 1957 and 1962, 26 having survived into preservation.
- Ten more members of this class were preserved but were scrapped either from accidents or as spare parts for other engines.
- Members of this class were given two nicknames, the first being "Toffee Apples" because of the shape of their control levers and the second "Skinheads", because the first few engines didn't have the codebox on the front of the roof.
- This diesel does not have a British Railways logo.