LNER Thompson Class A2/3

The London and North Eastern Railway Class A2/3 was a class of 4-6-2 steam locomotives built to Edward Thompson's requirement for a standard express passenger Pacific with 6 ft 2 in driving wheels. They were newly constructed engines, similar to the A2/2 rebuilds in frames, boiler and motion but with boiler pressure raised to 250 psi and smaller cylinders, and they kept Thompson's divided drive with three independent sets of Walschaerts valve gear. Fifteen were built to this original design. The first, No. 500, appeared in traffic in May 1946, just before Thompson retired, and fourteen more followed under his successor Arthur Peppercorn between July 1946 and September 1947. Peppercorn redesigned the remaining planned engines, which became the Peppercorn Class A2. All but the prototype were named after winners of major flat races. The class performed adequately but was troubled by frame flexing and outside steam pipe connections, and all were withdrawn between August 1962 and March 1965 with none preserved.