It was founded on 6 April 1900 in Berlin with the Disconto-Gesellschaft and the South West Africa Company as major shareholders.

[1] OMEG built a 600 mm (1 ft 11+5⁄8 in) narrow gauge railway extending 567 kilometres (352 mi) from Swakopmund on the Atlantic coast to the mines of Tsumeb.

[2] The first 225 kilometres (140 mi) of railway required 110 steel bridges to cross deeply eroded gullies through sparsely vegetated arid terrain.

German troops surrendered following defeat at Otavi in July, 1915; and service was re-established over the remaining 600 mm (1 ft 11+5⁄8 in) narrow gauge line from the railway shops at Usakos with freight transfer facilities at Karabib.

[9] The remainder of the line was regauged to 3 ft 6 in (1,067 mm) narrow gauge in 1961[10] and became part of the TransNamib.

[5] Equipment included: A special 7-tonne (6.9-long-ton; 7.7-short-ton) rail motor coach was built for an anticipated visit of Kronprinz Wilhelm in 1914.

A coach converted for meal service from 1916 to 1931 is believed to be the only 2 ft (610 mm) gauge dining car ever operated.

Four sleeping cars were built for the railroad in 1938;[18] when Henschel & Sohn delivered three more 2-8-2 SAR NG15 Class.