South West African Class Hd

Template:Use South African English {{Infobox locomotive | name = GSWA Class Hd 2-8-2
South West African Class Hd 2-8-2
South African Class NG5 2-8-2 | image = Class Hd 40 (2-8-2).jpg | alt = | caption = No. 40 displayed at Usakos, May 1984 | hatnote = | powertype = Steam | designer = Henschel and Son | builder = Henschel and Son | ordernumber = | serialnumber = 10720-10722 | buildmodel = Class Hd | builddate = 1912 | totalproduction = 3 | rebuilder = | rebuilddate = | numberrebuilt = | whytetype = 2-8-2 | uicclass = 1D1h2 | driver = Third coupled axle | gauge = Template:Track gauge narrow | leadingdiameter = 21+21⁄32 in (550 mm) | coupleddiameter = 33+7⁄8 in (860 mm) | trailingdiameter = 21+21⁄32 in (550 mm) | tenderdiameter = 20+1⁄2 in (521 mm) | minimumcurve = | wheelbase = 38 ft 6+5⁄8 in (11,751 mm) | engine total = 17 ft 11⁄16 in (5,199 mm) | leading = | coupled = 9 ft 7 in (2,921 mm) | trailing = | tender total = 11 ft 5+3⁄4 in (3,499 mm) | tenderbogie = 3 ft 3+3⁄8 in (1,000 mm) | pivotcentres = | wheelspacing = 1-2: 3 feet 1+7⁄16 inches (951 mm)
2-3: 3 feet (0.91 m)
3-4: 3 feet 1+7⁄16 inches (951 mm)

| length           =
| over couplers   = 49 feet 9+1⁄4 inches (15,170 mm)
| over bufferbeams=
| width            =
| height           = 10 feet 9+15⁄16 inches (3,300 mm)
| frametype        = Plate
| axleload         =
| leadingbogie/pony=
| coupled all      =
| coupled 1        =
| coupled 2        =
| coupled 3        =
| coupled 4        =
| coupled 5        =
| coupled 6        =
| coupled 7        =
| coupled 8        =
| trail bogie/pony =
| tenderbogieload  =
| tenderaxle       =
| weightondrivers =
| locoweight       = 32 long tons 17 hundredweight (33,380 kg)
| tenderweight     = 25 long tons 11 hundredweight ()
| locotenderweight = 58 long tons (58.93 t)
| tendertype       = Two-axle bogies
| fueltype         = Coal
| fuelcap          = 

  watercap  =    tendercap        =   sandcap          =   fireboxtype      = Round-top   firearea         =    boiler           =   boilertype       =   pitch            =   diameterinside   =   lengthinside                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              

The South West African Class Hd steam locomotives with a 2-8-2 wheel pattern were introduced in narrow gauge form in the year 1912 during the German colonial period.

That year, the German authorities governing German South West Africa procured a trio of Class Hd tender engines featuring a Mikado type (2-8-2) wheel configuration. These locomotives were leased to the Otavi Mining and Railway Company for operation on the railway route connecting Swakopmund and Karibib. Following their integration into the South African Railways fleet post World War I, the engines preserved their original German class designation and numbering, augmented by an "SW" prefix added to their numbers.

When the South African Railways eventually implemented a classification system for narrow gauge locomotives, these units were assigned to Class NG5, grouping them alongside comparable locomotives introduced by SAR in 1922.

Manufacturer

The rising transportation needs generated by the copper mining operations in Tsumeb created a demand for additional locomotives. In response, three narrow gauge 2-8-2 steam engines were constructed in 1912 by Henschel and Son in Germany for the German administration of German South West Africa (GSWA). These locomotives were classified as Class Hd, assigned numbers 40 through 42, and were leased to the Otavi Mining and Railway Company to operate on the route connecting Swakopmund and Karibib.

The designation "Hd" indicated that these locomotives were the fourth series produced by Henschel specifically for GSWA.

Characteristics

These locomotives featured superheating technology and utilized Heusinger valve gear along with piston valves and external plate frames. Designed to withstand operation across the Namib Desert, they included dust shields to guard the motion components against sand carried by strong winds. Instead of mounting the leading and trailing carrying wheels on separate bogie trucks, these wheels were fixed rigidly but configured as radial axles, permitting lateral movement relative to the locomotive frame. This design resulted in a rigid wheelbase measuring 17 feet 11⁄16 inch (5,199 millimetres), although notably, the leading carrying wheels were positioned behind rather than in front of the cylinders.

Originally, sandboxes were installed atop the boiler behind the dome. Their tenders, also manufactured by Henschel, ran on two bogies each with four wheels and carried 2 long tons 17 hundredweight (2.9 tonnes) of coal alongside a water capacity of 2,860 imperial gallons (13,000 litres). These locomotives came equipped for operation with air-braked trains, a braking system not yet adopted in South Africa at that time.

South African Railways

Following World War I, when South Africa assumed control over the former German colony and took charge of all railway services in South West Africa (SWA) in 1922, these locomotives kept their Hd classification and original engine numbers but added an "SW" prefix to avoid confusion with two narrow gauge Class NG1 locomotives of SAR numbered NG40 and NG41.

While in SAR service, these engines were also fitted with vacuum train brakes.

Reclassification

Between 1928 and 1930, SAR introduced a formal classification system for narrow gauge locomotives. At this time, these three units, together with six others built to an updated design and introduced by SAR in SWA during 1922, were grouped under Class NG5. The initial trio retained their original German engine numbers but dropped the SW prefix since the two Class NG1 engines with conflicting numbers were being retired from service.

Service

The locomotives served exclusively on the SWA network throughout their operational lifespan. Their withdrawal coincided with the 1960 conversion of the SWA system’s 2 ft gauge tracks to Cape gauge. Due to their incompatibility with the 2 ft gauge route in the Langkloof region, all six Class NG5 engines from 1922 were dismantled by 1962.

Number plate and commemorative plaques on No. 41, Otjiwarongo, 2011

Among the 1912-built ex-Class Hd locomotives, two were preserved for posterity. Locomotive No. 40 was installed as a static display at the Usakos railway station platform, while No. 41 found its place outside the Otjiwarongo railway station.

Commemoration

On 2 August 1985, a set of four commemorative South West African postage stamps was released, featuring the Class Hd locomotive to honor the narrow gauge engines that were instrumental in establishing rail transport within the territory. The stamp’s artwork was created by acclaimed designer and artist Koos van Ellinckhuijzen.

Illustration

• 
  Original works photograph of Class Hd no. 40, circa 1912