Data from:
Svein Sando's Railway Site [] (9 June 2004)--(Later link: The Semaphore, accessed for link update 10 July 2022.)--and the Jernbane (Iron Road) site [] (June 2004).
These small Prairie tanks were delivered in three separate years (1902, 1903, and 1906) and operated for the small VB until the NSB took it over on 1 Jan 1937. They continued in service for decades after that. Number 18 was sold to Klevos Cellulose, but the other three were retired from the NSB, the last (1 / 17) being withdrawn on 13 June 1963.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Class 50a |
| Locobase ID | 6194 |
| Railroad | Valdresbanen / NSB |
| Country | Norway |
| Whyte | 2-6-2T |
| Number in Class | 4 |
| Road Numbers | 1-4 / 17-20 |
| Gauge | Std |
| Number Built | 4 |
| Builder | Hartmann |
| Year | 1902 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | |
| Engine Wheelbase (ft / m) | 21.78 / 6.64 |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | 21.78 / 6.64 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 54,675 / 24,800 |
| Engine Weight (lbs / kg) | 67,351 / 30,550 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1056 / 4 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 1.90 / 2 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 30 / 15 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 41.30 / 1050 |
| Boiler Pressure (psi / kPa) | 188.50 / 1300 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 14.17" x 20.47" / 360x520 |
| Tractive Effort (lbs / kg) | 15,945 / 7232.54 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.43 |
| 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) | 14.31 / 1.33 |
| Evaporative Heating Surface (sq ft / m2) | 530 / 49.30 |
| Superheating Surface (sq ft / m2) | 161 / 15 |
| Combined Heating Surface (sq ft / m2) | 691 / 64.30 |
| Evaporative Heating Surface/Cylinder Volume | 141.85 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2697 |
| Same as above plus superheater percentage | 3318 |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |