 The railways of South Wales seem to have had a particular liking for the 0-6-2T type.This was because the nature of the work they undertook demanded high adhesive weight, plenty of power with good braking ability, but no need for outright speed, nor large tanks or bunker as the distances from pit to port were short.These Welsh locomotives were taken over by the GWR at the grouping in 1923 and many including seventeen of the Rhymney A, M, P and R's were rebuilt with GWR taper boilers.