GWR 4300 Class

The Great Western Railway (GWR) 4300 Class is a class of 2-6-0 (mogul) steam locomotives, designed by G.J. Churchward for mixed traffic duties. Three hundred and forty two examples were built from 1911-1932.

Background

In 1906 Churchward fitted a more powerful Standard No. 4 boiler to his successful 3100 Class 2-6-2T to create the GWR 3150 Class. These showed themselves to be successful locomotives but their 65 long tons 0 cwt (145,600 lb or 66 t) weight and 2,000 imp gal (9,100 l; 2,400 US gal) water capacity meant that they tended to be restricted to suburban passenger traffic. Churchward was looking forward to the replacement of various of his predecessor’s 4-4-0 classes on secondary duties. In 1911 he therefore designed a tender version of the 3150 class which would be suitable for a wide range of intermediate duties.

Design

The class was ‘a total synthesis of standard parts, using the outside cylinders of the Saint, the wheels of ’31XX’ 2-6-2 tank and the No.4 boiler, in its superheated form.’ No prototype was required as the fundamental design had proved itself.