In British Rail use the sub-class were particularly common in South Wales on heavy coal and metals work. They were particularly adept at working coal trains up and down the short but steeply graded branch lines around Swansea and Cardiff, to collieries such as Tower Colliery, Coedbach and Cwmbargoed. They operated merry-go-round trains of 32-ton HAA air-braked hoppers, usually numbering 32 wagons, between collieries, washeries, open cast mines and disposal points to power stations such as Aberthaw and occasionally further afield.