3650 is a representative of the class 57 shunting engine, which operated on the Great Western Railway. It was built at Swindon in 1939 and worked through to 1963 when it was sold to Stephenson Clarke Ltd to work on a colliery in South Wales. It was purchased from there by a member of the Great Western Society in 1969 and was transferred first to Hereford and then to Didcot. Restoration took nearly 20 years but it was finally returned to working order in 2008.
These small shunting engines were among the commonest on the railway. 863 class 57 engines were built in total and like the diesel class 08 shunter which I featured a few days ago they formed the invisible work horses which kept the railways running.