LMS 3-Cylindered Stanier 2-6-4T is a class of steam locomotive designed for work over the London Tilbury and Southend Railway. All 2500-36 were built in 1934 at Derby Works. The third cylinder was provided to allow increased acceleration between the many stops on the L.T.&S.R. line. From 1935 the LMS switched to constructing a very similar simpler 2-cylindered design.