South Africa, built to Imperial standards, were gauge. In practice, however, the two gauges are still treated as one and the same by, for example, the British Military. The same applied in the Zuid-Afrikaansche Republiek, which was being invaded by the British Army at the time. The difference was considered as insignificant and, in subsequent years, narrow-gauge locomotives regularly migrated between the narrow-gauge lines laid to German standards in South West Africa (SWA) and those laid to Imperial standards in South Africa. Service Royal Engineers During 1900, these two locomotives were used by the 47th Field Company Royal Engineers during the construction of the Bezuidenhout Light Railway, a light narrow-gauge railway line from Simmer and Jack’s siding near Germiston to a siege camp, away along the Bezuidenhout Valley. Pankop firewood line After the end of the war in 1902, the two locomotives and rolling stock were sold to a farmer as army surplus stock. He used it to haul firewood on a railway which he constructed from Pienaarsrivier on the mainline between Pretoria and Pietersburg, to Pankop on the Springbokvlakte. Central South African Railways The Pankop railway and rolling stock were taken over by the Central South African Railways (CSAR) in 1905. The CSAR extended the line to Settlers and opened the line to traffic on 21 June 1906. The intention was, on the one hand, to serve the immigrant farming community around Settlers and, on the other hand, to determine exactly how much a light railway of this nature could achieve in districts where the traffic would be light at the outset. In CSAR service, the locomotives became known as the Pankop engines and were referred to by their builder's works numbers 676 and 677. They were often coupled back-to-back to cope with heavier loads. South African Railways When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (Cape Government Railways, Natal Government Railways and CSAR) were united under a single administration to control and administer the railways, ports and harbours of the Union. Although the South African Railways and Harbours came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways were only implemented with effect from 1 January 1912. Narrow-gauge locomotives were included in the SAR’s narrow-gauge numbering scheme in 1912 and were allocated engine numbers with an "NG" prefix. A