anti-corrosive steel plates of a special heat-resisting quality. The brick arch was supported by five diameter arch tubes. The firebox was fitted with SAR standard type flexible stays and to allow easier access to the stays, the engine was equipped with a Watson cab with its slanted front which, like the Watson Standard boiler, was to become the standard on later SAR steam locomotive classes. The cab was of special light steel and was welded throughout. Service The Class 16E Pacifics were placed in service at Kimberley and regularly worked trains like the Union Express and Union Limited southward to Beaufort West and northward to Johannesburg respectively. The Union train was to become the Blue Train after the Second World War. Although the locomotives were never stationed at Braamfontein Loco in Johannesburg, they were serviced there in the process of working between Kimberley and Johannesburg. They proved to be very successful, efficient and economical in service when handling loads within their capacity. When the original wooden-bodied coaches of the Union trains were replaced with heavier steel-bodied air-conditioned coaches in 1939, however, the load increased to or more and the Class 16E was considered to be inadequate to the task and relocated to Bloemfontein in the Orange Free State. From here, they hauled regular passenger trains, including the Orange Express, working north to Johannesburg and south to De Aar as well as across to Kimberley. When air-conditioned lounge cars were added to trains like the Orange Express and Trans-Karoo, they were again considered not powerful enough for the additional load and were eventually withdrawn from service in 1972. Preservation When Watson retired in 1936, no. 858 was officially named after him. It carried the name Allan G Watson above its number plates on the cab sides. By the time the Class 16E was withdrawn from service, this engine bore the name Betty below the headlight. Two locomotives survive and were still relatively intact by 2015. No. 858 Betty was stored in the open at Beaconsfield in Kimberley while no. 857 Ann Smith • Bloemfontein Queen was in storage at Bloemfontein, parked under cover at the locomotive depot. Commemoration A 20c postage stamp depicting a Class 16E locomotive was one of a set of four commemorative postage stamps issued by the South African Post Office on 27 April 1983 to commemorate the steam locomotives of South Africa that were rapidly being withdrawn