These eight locomotives were ordered as faster suburban tanks to work the line between Springs and Randfontein. Vulcan Foundry built these 4-6-4T in 1904 at the same time as the class 9 Pacific. P.A. Hyde designed both classes to use the same boiler, cylinders and Stephenson valve gear. The class F also had bar frames, but smaller drivers with a diameter of 54 inches and an electric headlight. Some suffered from frame fractures, so that a reinforcement had to be added to all.

They were originally numbered 260 to 267, but with the founding of the South African Railways they received the new numbers 78 to 85. The class still carried the designation F. Reportedly they had the nickname “Chocolate Boxes”, maybe due to their black livery with red stripes and the maintenance that always kept these locomotives clean and in best condition. The last class member was withdrawn in 1931.