In 1954, the South African Railways placed 25 Class GO light branch line tank-and-tender Garratt articulated steam locomotives with a 4-8-2+2-8-4 Double Mountain type wheel arrangement in service.

Grubb, the Chief Mechanical Engineer (CME) of the SAR from 1949 to 1954, and an order for 25 of these locomotives was placed with Henschel and Son in Germany.

The Class GO turned out to be the last new steam locomotive type to be acquired by the Railways before full-scale electrification and dieselisation commenced.

It was also superheated, with a mechanical stoker, Walschaerts valve gear and piston valves, and was built on an identical one-piece cast steel frame with Franklin spring-loaded wedge horns, manufactured by Commonwealth Steel Castings Corporation in the United States of America.

[1] The engine units were identical to those of the Class GMA, except that the cylinders were lined and sleeved to reduce the bore from 20+1⁄2 to 18+1⁄2 inches (521 to 470 millimetres) to suit the smaller boiler.

This resulted in a correspondingly reduced tractive effort, from 60,700 to 49,430 pounds-force (270.0 to 219.9 kilonewtons) at 75% of boiler pressure.

On both locomotives, the engines for their mechanical stokers were situated in the cutout on the front or cabside ends of their coal bunkers, but on the right or driver's side on the Class GMA and on the left or stoker's side on the Class GO.

[7] As a result, the Transkei locomotives were soon also relocated to Natal, where most of them ended up on the North Coast line, shedded at Stanger, Empangeni and Gingindlovu.

They were soon withdrawn from the Eshowe branch, however, as a result of their tendency to start fires while climbing the 1 in 30 (3⅓%) gradients through sugar cane fields.