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The South African Railways Class GM 4-8-2+2-8-4 of 1938 is 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.〔South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended〕 ==Manufacturer== By 1938 the rapidly increasing traffic on the line from Johannesburg via Krugersdorp and Zeerust to Mafeking led to the preparation of designs for a Garratt locomotive that would be equal to two Class 19D locomotives by W.A.J. Day, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1936 to 1939. The initial designs of the Class GM were rejected by the Chief Civil Engineer, however, since the weight on the leading and trailing bogies exceeded the acceptable limit for rail.〔〔〔〔 To overcome this, the water capacity of the front water tank was reduced to while the rear bunker was redesigned to carry no water and with a coal capacity of . The meagre water supply, which was really only sufficient for shunting purposes, was augmented by semi-permanently coupling a specially built type X-17 auxiliary tank wagon with a capacity to the locomotive.〔〔〔 In all other respects the design followed that of the heavy Class GL Garratt. An order for sixteen locomotives was placed with Beyer, Peacock and Company in 1938, while their auxiliary water tank wagons 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.〔 The boilers were of outstanding proportions to enable the locomotives to cope with one particular bank on the Zeerust line that required continuous steaming for 75 minutes. They were superheated, with bar frames, mechanical stokers and Walschaerts valve gear, and since the proportions of the engine units and the wheel diameters were the same as that of the Class 19D, many of their parts were made interchangeable.〔〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「South African Class GM 4-8-2+2-8-4」の詳細全文を読む スポンサード リンク
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