South African Type X-17 water tender

South African type X-17 water tender

Type X-17 water tender (1953 model), 2009

Type and origin ♠ 1938 version - ♥ 1953 version Locomotive Class GM Designer South African Railways (W.A.J. Day) Builder South African Railways In service 1938, 1953

Specifications Configuration 2-axle bogies Gauge 3 ft 6 in (1,067 mm) Cape gauge Length 43 ft 10 3⁄4 in (13,379 mm) Width 8 ft 3 in (2,515 mm) Height 11 ft 7 1⁄4 in (3,537 mm) Bogies ♠ Diamond-frame ♥ SARCAST Wheel dia. 34 in (864 mm) Wheelbase 35 ft 9 in (10,897 mm)  • Bogie 5 ft 9 in (1,753 mm) Axle load 12 LT 8 cwt 3 qtr (12,640 kg)  • Bogie 24 LT 17 cwt 3 qtr (25,290 kg) Weight empty 43,211 lb (19,600 kg) Weight w/o 49 LT 15 cwt 3 qtr (50,590 kg) Water cap. ♠ 6,750 imp gal (30,700 l) ♥ 6,815 imp gal (31,000 l) Couplers AAR knuckle (SASKOP S)

Career Operators South African Railways Numbers ♠ 2291-2306 ♥ 2572-2596, 4051-4075

The South African type X-17 water tender was a Garratt steam locomotive tender.

Type X-17 water tenders first entered service in 1938, as auxiliary water tenders to the Class GM 4-8-2+2-8-4 Double Mountain type Garratt steam locomotives which entered service on the South African Railways in that year.

The first Type X-17 water tenders were built by the South African Railways (SAR) in its Pietermaritzburg shops in 1938. A redesigned second version was built in 1953.

During 1938 and 1939, the SAR 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. The locomotives were built by Beyer, Peacock and Company. The initial designs of the Class GM Garratt by W.A.J. Day, Chief Mechanical Engineer of the SAR from 1936 to 1939, were rejected by the Chief Civil Engineer, 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.

The Type X-17 water tender first entered service as tenders to these locomotives. 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 spite of initial criticisms and doubts, the unusual arrangement of auxiliary water tenders which had earlier only been seen on the Kitson-Meyer locomotives of the Cape Government Railways and Central South African Railways of 1903 and 1904 respectively, proved to be very effective and was later repeated upon the introduction of the Classes GMA and GO Garratts in 1954. On the Class GM, the 1,600 imperial gallons (7,270 litres) on-board water tank on the front engine unit was only used when the water tender was temporarily disconnected from the engine at running sheds.