South African Class NG5 2-8-2
|South African Class NG5 2-8-2|
Class NG5, circa 1960
|Designer||Henschel and Son|
|Builder||Henschel and Son|
|Serial number||18578-18583 |
|Gauge||2 ft (610 mm)|
|22 in (559 mm)|
|Driver diameter||33.875 in (860 mm)|
|22 in (559 mm)|
|Wheelbase||Total: 38 ft 6.625 in (11.751 m)
9 ft 7 in (2.921 m) coupled
17 ft 0.6875 in (5.20 m) total
3 ft 3.375 in (1.000 m) bogie
11 ft 5.75 in (3.499 m) total
|Length||49 ft 9.25 in (15.170 m)|
|Height||10 ft 9.9375 in (3.300 m)|
|Locomotive weight||32.85 long tons (33.4 t)|
|Tender weight||25.5875 long tons (26.0 t)|
|Locomotive and tender
|58.4375 long tons (59.4 t)|
|Tender type||2 axle bogies
20.5 in (521 mm) wheels
|Fuel capacity||2.85 long tons (2.9 t)|
|Water capacity||2,860 imp gal (13,000 l)|
|Boiler||3 ft 11.75 in (1.213 m) inside diameter
13 ft 1.5 in (4.001 m) inside length
5 ft 8.875 in (1.749 m) pitch
|Boiler pressure||171 psi (1,180 kPa)|
|Firegrate area||16.7 sq ft (1.551 m2)|
|114 tubes 1.75 in (44.4 mm) diameter
12 tubes 4.71875 in (120 mm) ext dia
880 sq ft (81.755 m2) 
|– Firebox||68 sq ft (6.317 m2)|
|– Total||948 sq ft (88.072 m2)|
|Superheater area||145 sq ft (13.471 m2)|
|Cylinder size||15.75 in (400 mm) bore
17.75 in (451 mm) stroke
|Tractive effort||16,610 lbf (73.9 kN) at 75% boiler pressure |
|Train brakes||Vacuum |
|Railroad(s)||South African Railways|
|Number in class||6|
In 1922 the South African Railways placed six narrow gauge steam locomotives with a 2-8-2 Mikado wheel arrangement in service on the Otavi branch in South West Africa. When a system of grouping narrow gauge locomotives into classes was eventually introduced somewhere between 1928 and 1930, they were classified as Class NG5.
Six narrow gauge steam locomotives with a 2-8-2 Mikado wheel arrangement were built for the South African Railways (SAR) by Henschel and Son in Germany in 1921. They were built to the same design as the three Class Hd locomotives that had been built in 1912 for the German administration in Deutsch-Südwest-Afrika (DSWA, now Namibia) for leasing to the Otavi Mining and Railway Company. The locomotives, numbered NG71 to NG76, were delivered in 1922.
Like the predecessor Class Hd, they were superheated, with Walschaerts valve gear and outside plate frames. The new locomotives differed from the Class Hd in having different boilers, which were of the same dimensions but with a different tube arrangement and, consequently, a slightly reduced total heating surface.
In keeping with SAR practice at the time, they had vacuum train brakes instead of the air brakes that the Class Hd was equipped with. In addition they had slide valves instead of the piston valves used on the Class Hd. Their driving wheel suspension arrangement also differed.
In service, these six locomotives and the three Class Hd locomotives were operated in a common pool. The system of grouping narrow gauge locomotives into classes was only adopted by the SAR somewhere between 1928 and 1930 and at that point these six locomotives as well as the three Class Hd locomotives were all classified as Class NG5.
The 1922 vintage Class NG5 was placed in service on the 352 miles (566 kilometres) narrow gauge line from Swakopmund on the Atlantic coast to Tsumeb and Grootfontein in South West Africa (SWA). They spent their whole service life in SWA, except for a brief period when one of them was sent to the Avontuur line in the Eastern Cape for trials. However, since it jammed on the tighter curves in the Langkloof despite having one set of flangeless driving wheels, it was soon returned to SWA.
They were all withdrawn from service when the SWA system was regauged to Cape gauge in 1960. Since they were unsuitable for use in the Langkloof, all six 1922 vintage Class NG5 locomotives were sold as scrap in 1962.
- South African Class Hd 2-8-2
- South African Class NG15 2-8-2
- The 2-8-2 "Mikado"
- Narrow Gauge locomotive numbering and classification
- List of South African locomotive classes
- Henschel-Lieferliste (Henschel & Son works list), compiled by Dietmar Stresow
- South African Railways and Harbours Narrow Gauge Locomotive Diagram Book, 2’0” Gauge, S.A.R. Mechanical Dept. Drawing Office, Pretoria, 28 November 1932
- South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
- Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 102, 110, 116–117. ISBN 0869772112.