The GWR locomotive standardisation policy pursued by
George Jackson Churchward envisaged a range of locomotive classes which would be suitable for the majority of duties, and yet which would share a small number of standard components. Among the designs suggested in 1901 was a 4-6-0 with diameter
driving wheels and the Standard No. 1 boiler. Although planned in 1901, none were built during Churchward's lifetime.
C.B. Collett, (Churchward's successor at
Swindon Works) rather introduced the
Hall class with diameter driving wheels. The
4300 Class of
2-6-0 tender locomotives had been introduced on the GWR for mixed traffic duties in 1911, and by 1932 there were 342 in service. However, by the mid-1930s some of the earlier examples were in need of attention and the class as a whole was struggling with some of the duties expected of them. Collett therefore revived the Churchward proposal, but modified the design to include a cab and controls to the current style. Between 1936 and 1939, one hundred 4300 Class were taken out of service and replaced by new
4-6-0 locomotives; eighty were of the 6800 (or
Grange) class and the remaining 20 were of the
7800 (or
Manor) class. It had been intended to replace all of the 4300 Class in this way, but the
Second World War stopped the programme. ==Design and Production==