 When a system of grouping narrow-gauge locomotives into classes was eventually introduced somewhere between 1928 and 1930, they were designated Class NG5.Six narrow-gauge steam locomotives with a 2-8-2 Mikado type wheel arrangement were built for the South African Railways (SAR) by Henschel and Son in Germany in 1921.They were built to the same design as the three Class Hd locomotives which had been built in 1912 for the German administration in German South West Africa (GSWA) for leasing to the Otavi Mining and Railway Company.