BR Standard Class 3MT

The BR Standard Class 3MT 2-6-0 was a series of twenty 2-6-0 Mogul locomotives designed by Robert Riddles and built at Swindon Works in 1954, occupying the middle ground between the lightweight Class 2 and the more powerful Class 4 in the BR Standard Mogul family. The Class 3 was intended for medium-weight secondary passenger and goods work on routes where the Class 2's modest power was insufficient but the Class 4's higher axle loading was a constraint. In practice only twenty were built — a small number compared to the eighty-plus examples of the Class 4 Mogul — reflecting the relatively narrow niche the Class 3 occupied.

The Class 3 2-6-0 shared the external family resemblance of the other Riddles Moguls: outside cylinders, BR Standard taper boiler, and the clean functional styling that characterised all the Standard designs. The 5 ft 3 in coupled wheels gave a reasonable balance between tractive effort and speed for the mixed secondary duties the class was assigned. Swindon's construction of what was essentially a Riddles design rather than a Churchward-derived type reflected the integrated approach to locomotive building across BR workshops that nationalisation had made possible.

The Class 3 Moguls worked secondary and semi-fast passenger duties principally in the Southern and Scottish Regions. Their short production run and the relatively rapid onset of diesel replacement meant the class had a brief working life; the last examples were withdrawn by 1967. One example, 77014, is preserved at the North Yorkshire Moors Railway.