Built in 1962 as D5855.
Renumbered into the TOPS series as 31321 in 1973.
Rebuilt as class 31/4 and renumbered 31468 in 1985.
Renumbered to 31568 in 1990.
Renumbered to 31468 in 1993.
Named The Engineman’s Fund 1993 to 1998.
Named Hydra 1999 to ????.
31568 at Northampton 1992