This locomotive was built by Robert Stephenson & Hawthorn in 1941 and was supplied new to Chatham Dockyard where it has spent all of its working life.
Initially it was owned by the Admiralty where the locomotive carried the Yard No 361.Later it became No 361 Ajax.
In 1972 the Admiralty disposed of all of its remaining steam locomotive at Chatham except this locomotive which was kept in working order until the dockyard closed in 1984.
After the dockyard closed the locomotive was placed in secure storage until the opening of the Historic Dockyard in 1985.
In December 1986 the locomotive was withdrawn from service for its first 10 year boiler overhaul in preservation.
At the end of its 10 year boiler certificate in December 1996, the locomotive was withdrawn from service and placed in store until 1999, when its second major overhaul began, with the locomotive returning to service in 2001. This work was carried out by Atkins at Swindon.
The locomotive was taken out of service again at the end of October 2011 to be completely stripped down for its third major overhaul. This work was carried out at the Historic Dockyard, Chatham, by members of the North Kent Industrial Locomotive Society.
By the summer of 2020 the locomotive was operational.