South West African 2-8-2 Locomotives in South_Africa


Class Details by Steve Llanso of Sweat House Media

Class Hd/NG5-40 (Locobase 993)

Data from South African Railways & Harbors 8 - 1941 locomotive diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. See also Wikipedia at [link], last accessed 1 June 2015 and Piet Conradie's blog post of 24 November 2007 for old STEAM LOCOMOTIVES in South Africa at [link] , last accessed 1 June 2015. Works numbers were 10720-10722 in 1912.

There's only so much a designer can do to give a 2'-ft gauge freight locomotive well-proportioned lines. The cab has to be big enough to house two full-grown people while the drivers must be tiny to generate tractive effort suitable for a Mikado layout. Conradie's post says that the engines had dust covers to protect the motion and that both auxiliary axles were mounted in radial boxes to allow lateral motion. They were delivered with large steam and sand domes, but the railway later removed the sand dome and replaced it with a pair of sand boxes mounted on the running board.

This trio was delivered to the SWA while that railway was still operated by German interests. The class was leased by the Otavi Mining and Railway Company to haul trains between Swakopmund and Karibib. When South Africa was installed as the Mandatory Power over SWA after World War I, the three engines remained in service and in 1928 were taken into the

These engines served the SAR well for almost forty years before entering retirement in November 1960 because the gauge was widened to 3 ft 6 in (1,067 mm).

Principal Dimensions by Steve Llanso of Middle Run Media
ClassHd/NG5-40
Locobase ID993
RailroadSouth West African
CountrySouth Africa
Whyte2-8-2
Number in Class6
Road Numbers40-42/NG40 - NG42
Gauge2'
Number Built6
BuilderHenschel & Sohn
Year1912
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.56 / 2.91
Engine Wheelbase (ft / m)17.06 / 5.20
Ratio of driving wheelbase to overall engine wheelbase 0.56
Overall Wheelbase (engine & tender) (ft / m)38.55 / 11.75
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)
Engine Weight (lbs / kg)73,584 / 33,377
Tender Loaded Weight (lbs / kg)57,540 / 26,100
Total Engine and Tender Weight (lbs / kg)131,124 / 59,477
Tender Water Capacity (gals / ML)3432 / 13
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.19 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)33.90 / 861
Boiler Pressure (psi / kPa)174 / 1200
High Pressure Cylinders (dia x stroke) (in / mm)15.75" x 17.72" / 400x450
Tractive Effort (lbs / kg)19,178 / 8699.00
Factor of Adhesion (Weight on Drivers/Tractive Effort)
Heating Ability
Tubes (number - dia) (in / mm)112 - 1.75" / 44
Flues (number - dia) (in / mm)14 - 4.724" / 120
Flue/Tube length (ft / m)13.12 / 4
Firebox Area (sq ft / m2)67.79 / 6.30
Grate Area (sq ft / m2)16.14 / 1.50
Evaporative Heating Surface (sq ft / m2)948 / 88.07
Superheating Surface (sq ft / m2)149 / 13.84
Combined Heating Surface (sq ft / m2)1097 / 101.91
Evaporative Heating Surface/Cylinder Volume237.25
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2808
Same as above plus superheater percentage3202
Same as above but substitute firebox area for grate area13,447
Power L16466
Power MT

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