 The result was a firebox which was virtually a copy of the one which was used on the Hendrie B locomotive which had been placed in service on the Natal Government Railways (NGR) in 1904.The locomotive used saturated steam and had flat "D" type slide valves, placed above the cylinders and operated by Stephenson Link valve gear through rocker shafts.The leading wheels were mounted in a spring control bogie which was designed to overcome the problems of excessive flange wear on the coupled wheels and rail cutting on curves.