page_title: South African Class GM 4-8-2+2-8-4
section_title: Manufacturer
hierarchical_section_title: South African Class GM 4-8-2+2-8-4 / Manufacturer
caption_attribution_description: English: W.A.J. Day, South African Railways Chief Mechanical Engineer (1936-1939)
context_page_description: The South African Railways Class GM 4-8-2+2-8-4 of 1938 was an articulated steam locomotive.
  During 1938 and 1939, the South African Railways placed sixteen Class GM Garratt articulated steam locomotives with a 4-8-2+2-8-4 Double Mountain type wheel arrangement in goods train service on the Mafeking line out of Johannesburg.
context_section_description: By 1938 the rapidly increasing traffic on the line from Johannesburg via Krugersdorp and Zeerust to Mafeking necessitated some means to increase its capacity quickly. Electrification to at least as far as Koster was proposed, but would take a considerable time to complete. This led W.A.J. Day, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1936 to 1939, to prepare designs for a Garratt locomotive which would be equal to two Class 19D locomotives.
  The initial designs of the Class GM Garratt were rejected by the Chief Civil Engineer, however, since the weight on the leading and trailing bogies of each engine unit would exceed the acceptable limit for the 60 pounds per yard (30 kilograms per metre) rail of the Mafeking line. To overcome the axle load objections, the water capacity of the front water tank was reduced to 1,600 imperial gallons (7,270 litres) while the rear bunker was redesigned to carry no water and with a coal capacity of 10 long tons (10.2 tonnes). The meagre water supply, which would really only be sufficient for shunting purposes, would be augmented by semi-permanently coupling a purpose-built auxiliary water tender to the locomotive.
  In effect, since Garratt locomotives had hitherto been considered as tank engines because they carry all their water on board, this arrangement introduced the tank-and-tender Garratt. In all other respects, Day's design followed that of the heavy Class GL Garratt. An order for sixteen locomotives was placed with Beyer, Peacock and Company in 1938, while the sixteen Type X-17 water tenders were built in the Pietermaritzburg shops. The locomotives were delivered in 1938 and 1939, erected in the Durban shops and numbered in the range from 2291 to 2306.
caption: W.A.J. Day
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