When the 0-6-2 tank locomotives became too weak on the winding coal lines in South Wales, Churchward constructed a successor. Initially, a 2-8-2 tank locomotive based on the class 2800 was planned, but in the end he left out the trailing axle to negotiate the tight curves and thus designed the first British 2-8-0 tank locomotive. The wheel flanges of the second and third driving axles were made thinner and the fourth driving axle had lateral play. In tests, the locomotives were said to be able to negotiate curves with a radius of 130 feet without derailing. 