Developed by Riddles as part of the British Railways drive to standardised classes, the Class 4 tanks drew heavily on Stanier's 2-6-4 tank designed for the LMS (see the 3 1/2 inch gauge Jubilee currently in stock). Arguably the most successful of the standard classes, 155 engines were built between 1951 and 1957 - several survive in preservation.
This is an older model, well-built and in remarkably good mechanical condition, though the paintwork is pretty grim. The engine is highly-detailed, allegedly built from Brighton works drawings.
Silver-soldered copper boiler with superheaters, fed by injector, axle pump and auxiliary hand pump in bunker. Twin safety valves, working presure 80 psi. Twin water gauges with blowdowns.
Twin cylinders with slide valves actuated by Walschaerts valve gear. Twin mechanical cylinder lubricators mounted on running boards. Bronze crosshead slippers, well-detailed motion work. Steam-operated drain cocks with valve in cab.
I have driven this powerful engine on several occasions - it
runs well and has a boiler certificate valid to 2005.
Weight approx 150 pounds