This locomotive was built by Robert Stephenson & Hawthorn in 1941 and it spent all of its working life based at Stewarts and Lloyds at Corby where it hauled iron ore wagons.
It was withdrawn from service in 1969.
The locomotive was purchased by two members of the East Anglia Railway Museum’s Bishops Stortford branch and arrived at the museum in 1973. It was then fitted with vacuum brakes and steam heating equipment in order that it could work passenger trains. In 1974 it was given the name Penn Green after the shed complex where it was based.
In 1987 the locomotive was purchased by the museum from the two owners.
After many years of use as the main locomotive on service trains the locomotive was withdrawn early in 1992 for major restoration work, including the construction of a new firebox. The locomotive returned to traffic in early 1993 in a new Blackberry Red livery.
The locomotive was taken out of traffic in late December 1994 for rectification of defects in the new firebox. Contractual problems ensued, which were resolved in late December 2000.
Work to bring the locomotive back into use recommenced in 2007, and following a major overhaul, which resulted in the original saddle tank being replaced with side tanks and the locomotive being rebuilt as a licensed Thomas the Tank Engine replica.
In the guise of Thomas the locomotive has run on a number of heritage railways and has visited the Netherlands.
It returned to service in March 2008 and with the boiler certificate due to expire in 2018 it was taken out of service again in the spring of 2017 and overhauled again. The current boiler certificate is valid until 2027.