This locomotive was built in 1944, to a Hunslet Engine Company design, by Hudswell Clarke for the Ministry of Defence. It then entered service as WD71499.
See LNER class J94 for details.
Along with many other of the Austerity locomotives WD 75091 was bought by the National Coal Board.
It is currently being restored by Bryn Engineering and is planned to be used on the Embsay & Bolton Abbey Steam Railway.