SR USA class

The SR USA class are some ex-United States Army Transportation Corps S100 Class steam locomotives purchased and adapted by the Southern Railway (SR) after the end of the Second World War to replace the LSWR B4 class then working in Southampton Docks. SR staff nicknamed them "Yank Tanks". Origins The United States Army Transportation Corps built 382 S100 Class 0-6-0 tank engine for use in the Second World War. They were shipped to the British War Department in 1943, and stored awaiting the invasion of Mainland Europe. Most went overseas but some remained in store. By 1946 the SR needed either to renew or replace the ageing B4, D1 and E1 class tanks used in Southampton Docks, but Eastleigh Works was not in a position to do so in a timely manner or at an economic price. The replacement locomotives would need to have a short wheelbase to negotiate the tight curves found in the dockyard, but be able to haul heavy goods trains as well as full-length passenger trains in the harbour area. The railway's Chief mechanical engineer, Oliver Bulleid therefore inspected the surplus War Department tank locomotives. The Hunslet Austerity 0-6-0ST locomotives stored at the Longmoor Military Railway proved to be unsuitable for dock work because of their wheelbase and inside cylinders, and also many of the survivors were in poor condition. However, the S100s stored at Newbury Racecourse had a wheelbase, outside cylinders and had hardly been used. Those available for sale had been built by the Vulcan Iron Works of Wilkes-Barre Pennsylvania and H. K. Porter, Inc, of Pittsburgh.