 has a 180 or 200 psi boiler).The 15th class were Intended for the long run from Bulawayo to Mafeking, South Africa via Francistown and Gaborone, Bechuanaland (now Botswana) but this was dependent on the strengthening of certain bridges which could not be carried out due to the war.They therefore worked the Salisbury-Gwelo section and proved their value there, so after the war more were ordered.