Six tank locomotives, designed by SAR Chief Mechanical Engineer D.A. Hendrie and built by Nasmyth, Wilson and Company, were introduced on the SAR in 1915. Designated Class J, they had Walschaerts valve gear and Belpaire fireboxes and used saturated steam. Acquired to cope with increasing traffic on the Natal South Coast, but unable to handle the rapidly increasing loads due to their small proportions, they soon ended up being employed as shunting engines in the Durban harbour, at Mossel Bay and in the Cape Midlands, until they were withdrawn from service by 1957.