South West African Class Hd

DSWA Class Hd 2-8-2
South West African Class Hd 2-8-2
South African Class NG5 2-8-2

No. 40 plinthed at Usakos, May 1984
Type and origin
Power type Steam
Designer Henschel and Son
Builder Henschel and Son
Serial number 10720-10722
Model Class Hd
Build date 1912
Total produced 3
Specifications
Configuration 2-8-2 (Mikado)
Driver 3rd coupled axle
Gauge 600 mm (1 ft 11 58 in) narrow
Leading dia. 21 2132 in (550 mm)
Coupled dia. 33 78 in (860 mm)
Trailing dia. 21 2132 in (550 mm)
Tender wheels 20 12 in (521 mm)
Wheelbase 38 ft 6 58 in (11,751 mm)
  Engine 17 ft 1116 in (5,199 mm)
  Coupled 9 ft 7 in (2,921 mm)
  Tender 11 ft 5 34 in (3,499 mm)
  Tender bogie 3 ft 3 38 in (1,000 mm)
Wheel spacing
(Asymmetrical)
1-2: 3 ft 1 716 in (951 mm)
2-3: 3 ft 4 18 in (1,019 mm)
3-4: 3 ft 1 716 in (951 mm)
Length:
  Over couplers 49 ft 9 14 in (15,170 mm)
Height 10 ft 9 1516 in (3,300 mm)
Frame type Plate
Loco weight 32 LT 17 cwt (33,380 kg)
Tender weight 25 LT 11 cwt 3 qtr (26,000 kg)
Total weight 58 LT 8 cwt 3 qtr (59,380 kg)
Tender type 2-axle bogies
Fuel type Coal
Fuel capacity 2 LT 17 cwt (2.9 t)
Water cap 2,860 imp gal (13,000 l)
Firebox type Round-top
  Firegrate area 16.7 sq ft (1.55 m2)
Boiler:
  Pitch 5 ft 8 78 in (1,749 mm)
  Diameter 3 ft 11 34 in (1,213 mm)
  Tube plates 13 ft 1 12 in (4,000 mm)
  Small tubes 114: 1 34 in (44 mm)
  Large tubes 12: 4 2332 in (120 mm)
Boiler pressure 171 psi (1,179 kPa)
Heating surface 968 sq ft (89.9 m2)
  Tubes 900 sq ft (84 m2)
  Firebox 68 sq ft (6.3 m2)
Superheater:
  Heating area 169 sq ft (15.7 m2)
Cylinders Two
Cylinder size 15 34 in (400 mm) bore
17 34 in (451 mm) stroke
Valve gear Walschaerts
Valve type Piston
Loco brake Air
Train brakes Air & vacuum
Couplers Buffers and chain
Performance figures
Tractive effort 16,610 lbf (73.9 kN) @ 75%
Career
Operators Otavi Mining and Railway Co.
South African Railways
Class DSWA Class Hd, SAR Class NG5
Number in class 3
Numbers SW40-SW42
Delivered 1912
First run 1912
Withdrawn 1960

The South West African Class Hd 2-8-2 of 1912 was a narrow gauge steam locomotive from the Deutsch-Südwest-Afrika era.

In 1912, the German administration in Deutsch-Südwest-Afrika acquired three Class Hd tender locomotives with a 2-8-2 Mikado type wheel arrangement, for lease to the Otavi Mining and Railway Company to use on the line from Swakopmund to Karibib. When these locomotives were taken onto the roster of the South African Railways after the First World War, they retained their German classification and engine numbers, but with an "SW" prefix to their numbers.[1][2]

When a system of grouping narrow gauge locomotives into classes was eventually introduced by the South African Railways, they were designated Class NG5, along with similar locomotives which were placed in service by the South African Railways in 1922.[1][3][4]

Manufacturer

Increasing traffic demands arising from the copper mines at Tsumeb led to a requirement for more locomotives. Three narrow gauge 2-8-2 Mikado type steam locomotives were built for the German administration in Deutsch-Südwest-Afrika (DSWA) by Henschel and Son in Germany in 1912. They were designated Class Hd, numbered in the range from 40 to 42, and leased to the Otavi Mining and Railway Company for use on the section between Swakopmund and Karibib.[1][2][5]

The "Hd" classification identified the locomotive type as the fourth class to have been built for DSWA by Henschel.[1]

Characteristics

The locomotives were superheated, with Walschaerts valve gear, piston valves and outside plate frames. Since they were to be used across the Namib Desert, they were equipped with dust covers to protect the motion from wind-blown sand. Their rigidly mounted leading and trailing carrying wheels were arranged as radial axles, to allow for sideways motion of the wheels in relation to the locomotive frame, since the locomotive did not have separate bogie trucks. This resulted in a rigid wheelbase of 17 feet 1116 inch (5,199 millimetres), even though the leading carrying wheels were arranged to the rear instead of in front of the cylinders.[1][2]

As built, the sand boxes were mounted on top of the boiler, aft of the dome. Their tenders, also built by Henschel, rode on two four-wheeled bogies and had a coal capacity of 2 long tons 17 hundredweight (2.9 tonnes) and a water capacity of 2,860 imperial gallons (13,000 litres). The engines were equipped for trains with air brakes, which was not yet in use in South Africa at the time.[1][2]

South African Railways

After the First World War, when the former German colony came under South African administration and all railway operations in South West Africa (SWA) were taken over by the South African Railways (SAR) in 1922, these locomotives retained their Hd classification and engine numbers, but with an "SW" prefix to the numbers. This was to prevent confusion with the two Class NG1 narrow gauge locomotives of the SAR, which were numbered NG40 and NG41.[1]

In SAR service, the locomotives were also equipped with vacuum train brakes.[3]

Reclassification

A system of grouping narrow gauge locomotives into classes was only adopted by the SAR somewhere between 1928 and 1930 and at that point, these three locomotives, along with six similar locomotives which were built to a revised design and placed in service by the SAR in SWA in 1922, were all designated Class NG5. The original three locomotives retained their original German engine numbers, but the SW prefix was done away with, since the two Class NG1 locomotives with duplicate engine numbers were being withdrawn from service at the time.[1][3]

Service

They remained in service in SWA for their entire working lives, until they were all withdrawn from service when the narrow gauge lines of the SWA system was regauged to Cape gauge in 1960. Since they were unsuitable for use on the narrow gauge line in the Langkloof, all six of the 1922 vintage Class NG5 locomotives were sold as scrap in 1962.[1]

Number plate and plaques on no. 41, Otjiwarongo, 2011

Two of the 1912 vintage ex Class Hd locomotives were preserved. No. 40 was plinthed on the Usakos railway station platform, while no. 41 was plinthed outside Otjiwarongo railway station.[6]

Commemoration

A postage stamp, depicting the Class Hd locomotive, was one of a set of four commemorative South West African postage stamps which were issued on 2 August 1985 to commemorate the narrow gauge locomotives which pioneered railways in the territory. The stamp design was by the noted stamp designer and artist Koos van Ellinckhuijzen.[7][8]

Illustration

References

  1. 1 2 3 4 5 6 7 8 9 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 102, 110, 116–117. ISBN 0869772112.
  2. 1 2 3 4 Espitalier, T.J.; Day, W.A.J. (1947). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, October 1947. pp. 859-860.
  3. 1 2 3 South African Railways and Harbours Narrow Gauge Locomotive Diagram Book, 2'0" Gauge, S.A.R. Mechanical Dept. Drawing Office, Pretoria, 28 November 1932
  4. South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended
  5. Henschel-Lieferliste (Henschel & Son works list), compiled by Dietmar Stresow
  6. Middleton, John N. (2002). Railways of Southern Africa Locomotive Guide - 2002 (as amended by Combined Amendment List 4, January 2009) (2nd, Dec 2002 ed.). Herts, England: Beyer-Garratt Publications. p. 33.
  7. Philatelic Bulletin 44, issued by Philatelic Services and INTERSAPA, 1985
  8. De Jager, Okkie and Steenkamp, Riaan - The Art of J.J. (Koos) van Ellinckhuijzen
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