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 [], last accessed 1 June 2015. Works numbers were 18578-18583 in 1921
Apparently the three SWA 2-ft-gauge Mikados of 1912 (Locobase 993) were very satisfactory pocket haulers because after World War I, the SAR ordered six more for its SouthWest Africa Mandate in 1921. The design's only difference was a subtle shift in the tube-flue balance from 112 tubes and 14 tubes to 114 tubes and 12 flues.
The Wikipedia entry says that this class worked the 567 km (352 miles) line between Swakopmund on the Atlantic coast to Tsumeb and Grootfontein in South West Africa.
These engines served the SAR well for almost forty years before entering retirement in November 1960.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | NG5-71 |
| Locobase ID | 16058 |
| Railroad | South African Railways (SAR) |
| Country | South Africa |
| Whyte | 2-8-2 |
| Number in Class | 6 |
| Road Numbers | NG71 - NG76/18578-18583 |
| Gauge | 2' |
| Number Built | 6 |
| Builder | Henschel & Sohn |
| Year | 1922 |
| Valve Gear | Walschaert |
| 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) | 114 - 1.75" / 44 |
| Flues (number - dia) (in / mm) | 12 - 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) | 145 / 13.47 |
| Combined Heating Surface (sq ft / m2) | 1093 / 101.54 |
| Evaporative Heating Surface/Cylinder Volume | 237.25 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2808 |
| Same as above plus superheater percentage | 3173 |
| Same as above but substitute firebox area for grate area | 13,329 |
| Power L1 | 6377 |
| Power MT | |