In 1931, three narrow gauge Class NG15 locomotives with a 2-8-2 Mikado type wheel arrangement, similar in design to the existing Class Hd and Class NG5 locomotives, were acquired by the South African Railways for the Otavi Mining and Railway Company in South West Africa. More were purchased for the Otavi Railway and the Tsumeb Copper Corporation during the subsequent years, eventually bringing the total number of these locomotives to 21 by 1958.
Thanks to Paul Hobbs for his mesh library elements, some of which have been used in the model.