cab was wide and was fitted with hinged adjustable glass windscreens for the lookout and a rigid extended footplate instead of the older fall plate. The cab footsteps were attached to the rigid platform. The engine was tended by a new Type JT1 tender, built with an underframe and bogies identical to those of the Type JT tender. As on the Type GT tender of the Class S, the top sides of the Type JT1 tender's coal bunker were set inwards to afford the crew the maximum rearward field of vision. The front of the engine and the back of the tender were fitted with modified and strengthened draft gear. The intermediate drawgear between engine and tender was similar in design to that of the Class 15F. The engine and tender were both fitted with vacuum brakes. Service The Class S1 was noted for its efficient and economical working. They were the SAR's largest and finest shunting locomotives with an enormous shifting and accelerating ability and could cope with block loads of up to . They were initially placed in service in the yards in Cape Town, but they ended up being used mainly in marshalling yards on the Western Transvaal System and also on the Cape Northern System, employed at Braamfontein, Millsite in Krugersdorp, Bloemfontein and Kimberley. Bloemfontein had one of the SAR's more important marshalling yards where goods trains from the north were sorted into consists bound for East London, Port Elizabeth, Mossel Bay, Cape Town and a host of Cape country towns. In its heyday, Bloemfontein's retarder yard had 40 tracks, 24 for southbound traffic and 16 for northbound. There were two humps with two primary and five secondary retarders, the latter split into three for southbound and two for northbound traffic. The hump leads were served around the clock by Class S1 engines no. 374 and 375. By the 1970s they were distributed between Beaconsfield, Bloemfontein, Germiston, Kaserne, Springs and Witbank. By 1982 they were all stationed at Germiston and its sub-depot at Kaserne, after which they began to be withdrawn from service. The withdrawal was probably expedited by the closure of the Koedoespoort works in Pretoria to steam repairs, since it was impractical to let them do long-distance running to the next nearest steam locomotive works at Bloemfontein. None of them were sold into industrial service. Works numbers The builders, works numbers, years built and