Data from "Locomotives of the Otavi Ry" The Locomotive Magazine, Vol XIII (15 August 1907), p.147. Works numbers were 7298-7300 (1905), 7623-7626 and 7740-7745 (1906), and 8610-8611 (1907).
The Jung radial tanks that opened the Otavi line (Locobase 10621) were soon joined by this more powerful class of similar engines. Unlike the earlier Jungs, however, these engines were supplied with 10-kilolitre (2,642 US gallon) tenders to compensate for the scarcity of water supplies in the 150-km (93-mile) stretch between Swakopmund and Usakos. The tenders also carried 3.5 long tons (3.92 short tons) of coal. The Hb were rated at 100 tons on the level at 40 km/h (25 mph); the speed dropped to 15 km/h (9.3 mph) on the steepest inclines of 2%.
All were taken into the South African Railways system in 1916 after German forces were forced to surrender in 1915.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Hb |
| Locobase ID | 10622 |
| Railroad | Otavi |
| Country | German Southwest Africa |
| Whyte | 0-6-2 |
| Number in Class | 12 |
| Road Numbers | |
| Gauge | 60 cm |
| Number Built | 12 |
| Builder | Henschel & Sohn |
| Year | 1905 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 6.40 / 1.95 |
| Engine Wheelbase (ft / m) | 13.29 / 4.05 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.48 |
| Overall Wheelbase (engine & tender) (ft / m) | 13.29 / 4.05 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | |
| Engine Weight (lbs / kg) | 50,265 / 22,800 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 264 / 1 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 0.80 / 1 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 33.90 / 860 |
| Boiler Pressure (psi / kPa) | 203.10 / 1400 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 12.6" x 17.72" / 320x450 |
| Tractive Effort (lbs / kg) | 14,326 / 6498.17 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | |
| Grate Area (sq ft / m2) | 11.08 / 1.03 |
| Evaporative Heating Surface (sq ft / m2) | 611 / 56.80 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 611 / 56.80 |
| Evaporative Heating Surface/Cylinder Volume | 238.92 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2250 |
| Same as above plus superheater percentage | 2250 |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |