9466 was built by Robert Stephenson and Hawthorn Ltd in Darlington in 1952. It was initially allocated to the Gloucester depot in February 1952 but in March of that year, it moved to Worcester, where it was used on pilot work as well as shunting and on local passenger and freight duties. It stayed at Worcester for nine years, after which it was overhauled at Wolverhampton Stafford Road and then transferred to Bristol (St Phillips Marsh) in 1961.
9466 worked at Tondu depot from June 1962 and Radyr shed a year later. 9466 was withdrawn for scrap in June 1964 after a working life of less than 12 years. It spent 11 years at Woodham Brothers, before moving to Quainton in September 1975. It was bought in 1977 by Dennis Howells.
Since then, it has visited many heritage railways and has worked special steam trains for London Underground.
During 2006, it was fitted with Train Protection and Warning System and On Train Monitoring and Recording systems which are mandatory for mainline working. Following recertification at Tyseley for mainline running, 9466 hauled several trains on the main line during 2006 – 2009.
In June 2019, Jonathan Jones Pratt, the Chairman of the West Somerset Railway PLC, announced that he had purchased the locomotive, with a desire to run it on the West Somerset Railway but this could not be done until Red Route status was reinstated on the railway, which is required before heavier axle load locomotives can run on the whole line. Initially, it ran on the South Devon Railway.
By October 2019, the locomotive had been moved to the Gloucestershire Warwickshire Railway.
In July 2020, it was announced that the locomotive would be moving to the Ecclesborourne Valley Railway, where it arrived at the end of September 2020.
In March 2022, it arrived at the West Somerset Railway.
Its current boiler certificate expires at the end of 2025.