The South African Railways Class NG4 4-6-2T of 1911 was a narrow-gauge steam locomotive from the pre-Union era in the Colony of Natal. In 1911, shortly before being amalgamated into the South African Railways, the Natal Government Railways placed the first two of seven Pacific type narrow-gauge tank steam locomotives in service. In 1912, when these two locomotives were assimilated into the South African Railways, they retained their engine numbers, but with an "NG" prefix added. Five more of these locomotives were delivered to the South African Railways in 1913 and 1914. When a system of grouping narrow-gauge locomotives into classes was eventually introduced somewhere between 1928 and 1930, they were all designated Class NG4. Natal's narrow gauge By 1906, the Natal Government had realised that light railways were essential as feeders to open up fertile districts which were distant from the existing main- and branch lines, particularly when the intervening stretches of country were difficult from an engineering point of view. The third narrow-gauge railway line in Natal was the Alfred County Railway which ran from Port Shepstone on the South Coast to Harding. The first section to Paddock was opened on 8 November 1911. Manufacturers Like their two predecessor locomotive types, the Hunslet Side-tank of 1906 and the Hawthorn Leslie Side-tank of 1907, this third batch of narrow-gauge Pacific locomotives of the Natal Government Railways (NGR) were also built to the design of NGR Locomotive Superintendent D.A. Hendrie, using the Hawthorn Leslie drawings for the Class NG3. The majority of their parts were interchangeable with those of the earlier engines. Between 1911 and 1913, the High Com­mis­sioner for the Union of South Africa placed three orders for altogether seven of these locomotives with Kerr, Stuart and Company. Two locomotives were ordered on 10 January 1911. They were dispatched from the factory in September of that same year with Kerr, Stuart works numbers 1207 and 1208, for delivery to the Natal Government Railways. They were numbered NGR 10 and 11 and designated Class N on the NGR roster. Two more were ordered on 28 September 1912. They were dispatched from the factory in April and May 1913 with works numbers 1294 and 1295, for delivery to the South African Railways (SAR). They were numbered SAR NG12 and NG13. Three more were ordered on 10 June 1913. They were dispatched from the factory in July 1914 with works numbers 1342