 Several of the most successful features of the class were used by Drummond on his other designs.Thus the boiler, cylinders and motion were identical and interchangeable with those used on his 700 class 0-6-0 freight locomotives of 1897 and the same boiler was used on his C8 4-4-0 passenger class.According to Bradley (p. 108) the original working pressure was reduced to to reduce wear on the boilers in 1900 when it became clear that they were no longer to be used for sustained high speed running.