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

300px Ex Class Hd no. SW40, reclassified as Class NG5 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" Gauge 600 mm (1 ft 11 5⁄8 in) narrow gauge Leading dia 21.65625 in (550 mm) Driver diameter 33.875 in (860 mm) Trailing dia 21.65625 in (550 mm) Wheelbase Total: 38 ft 6.625 in (11,751 mm) Engine: 9 ft 7 in (2,921 mm) coupled 17 ft 0.6875 in (5.20 m) total Tender: 3 ft 3.375 in (1,000 mm) bogie 11 ft 5.75 in (3,499 mm) total Length 49 ft 9.25 in (15,170 mm) Height 10 ft 9.9375 in (3,300 mm) Frame Plate frame Loco weight 32.85 long tons (33.4 t) Tender weight 25.5875 long tons (26.0 t) Loco & tender weight 58.4375 long tons (59.4 t) Tender type 2 axle bogies Wheels dia Fuel type Coal Fuel capacity Water cap 2,860 imp gal (13,000 L) Boiler 3 ft 11.75 in (1,213 mm) int dia 13 ft 1.5 in (4,000 mm) int length 5 ft 8.875 in (1,749 mm) pitch Boiler pressure Firegrate area 16.7 sq ft (1.551 m2) Heating surface 968 sq ft (89.930 m2)  • Tubes 112 tubes ext dia 14 tubes ext dia 900 sq ft (83.613 m2)  • Firebox 68 sq ft (6.317 m2) Superheater:  • Heating area 169 sq ft (15.701 m2) Cylinders Two Cylinder size bore stroke Valve gear Walschaerts Loco brake Air Train brakes Air, as built Air & vacuum, modified

Performance figures Tractive effort 16,610 lbf (74 kN) at 75% pressure

Career Operators Otavi Mining and Railway Company South African Railways Class Otavi Class Hd SAR Class NG5 Number in class 3 Numbers SW40-SW42 Delivered 1912 First run 1912 Withdrawn 1960 Disposition Retired

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

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

When a system of grouping narrow gauge locomotives into classes was eventually introduced by the South African Railways between 1928 and 1930, they were reclassified as Class NG5 along with similar locomotives that were placed in service by the South African Railways in 1922.

Manufacturer

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.

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

The locomotives were superheated, with Walschaerts valve gear, piston valves and outside plate frames. They were equipped for trains with air brakes, which at the time was not yet used in South Africa. Since they were to be used across the Namib Desert, they were equipped with dust covers to protect the motion. Their leading and trailing carrying wheels were arranged as radial axles to allow for sideways motion of the wheels with respect to the locomotive frame, since the locomotive did not have separate bogie trucks.

South African Railways

After World War I, 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 German Hd classification and engine numbers, but with an "SW" prefix to the numbers. This was to prevent confusion with the two Class NG1 locomotives of the SAR, which were numbered NG40 and NG41.

In SAR service they were also equipped with vacuum train brakes.

Reclassification

File:SAR Class NG5 (2-8-2) Today.png

Ex Class Hd no. SW41, Class NG5 no. 41, plinthed in Otjiwarongo

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 that were placed in service by the SAR in SWA in 1922, were all classified as Class NG5. These 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 at the time being withdrawn from service.

Service

They remained in service in SWA for their entire working lives, until they were all withdrawn from service when 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.

Two of the 1912 vintage ex Class Hd locomotives were preserved. Number 40 was plinthed on the Usakos station platform, while number 41 was plinthed outside Otjiwarongo Railway Station.

Commemoration

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

Illustration

• Class Hd 2-8-2.jpg

  Works picture of Class Hd no. 40, c. 1912