This small 'bow-framed' petrol driven locomotive was supplied to the War Department during World War One. Later, it worked at Porton Down (the infamous Nuclear, Biological & Chemical (NBC) Research Establishment), before being bought for preservation. The locomotive's original petrol engine had been replaced with a similar one at some time before it came to Wales.
Having arrived in 1997 (J.121), restoration to full working working order began in 1998 (J.126). The locomotive engine became operational once more in July 2009. By October 2009, the locomotive was able to move under its own power again, managing to haul eight tons on test, and has a surprising turn of speed... “it goes like a bat out of hell”, said one observer. “Maybe that’s to help it escape German gunfire?”
A similar 'bow-framed' locomotive, albeit a 40HP version, was used in 1941 on the Welsh Highland Railway demolition train.