5051 Drysllwyn Castle is an example of the GWR 4-6-0 Castle class, which was an updated version of their earlier star class and was designed by Collett from 1923. In all, 171 Castle class locomotives were built for the Great Western.
5051 left Swindon Works in 1936, with its current name, but the following year it was renamed Earl Bathurst. it retained this name for the remainder of its active life. It was based at Swansea and worked trains from there to London and the Midlands. It was withdrawn in 1963 and sent to Woodham brothers at Barry, where it remained until 1970 when it was taken to Didcot. It was restored to mainline condition in 1980, and worked rail tours until its withdrawal in 2008.
video by 45064 (http://www.youtube.com/user/45064?feature=watch)
It is currently on static display at the great Western society in Didcot