50 U class locomotives were built for Southern railway between 1928 and 1931. They were designed by Maunsell to haul passenger services and were influenced by design features from engines on the GWR and Midland Railway and as a development of the K class locomotive already in service on Southern. The class was withdrawn from service in 1966.
1638, one of the later engines to be built, went to Barry scrapyard after withdrawal from service , but was rescued and arrived at the Bluebell railway in 1980. the owners were already restoring another locomotive and so restoration of 1638 was not completed until 2006.
There are currently 4 U class locomotives in preservation, 2 at Bluebell Railway (1 in running order) and 2 at Swanage Railway (1 in running order).