Data from "Locomotive for the Soudan [sic] Government Railways", The Engineer, Volume 112 (28 July 1911), p. 100.
This mixed-traffic Pacific was part of an order for nine locomotives that was divided into five delivered with saturated boilers and four, including this one, with a Schmidt superheater. All had Belpaire fireboxes and both types were built to the design of Mr.
C. G. Hodgson, Chief Mechanical Engineer, Atbara in the Sudan.
Locobase juggled the heating surface area, increasing it from the 946 sq ft in the Engineer's story. That figure didn't jibe with the results of the tube and flue area calculations, which I presumed to be correct. It's also possible, however, that any one of a number of pieces of data--tube and flue counts, tube diameter, or tube length-- is also incorrect
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 120 - superheated |
| Locobase ID | 20056 |
| Railroad | Sudan Railway |
| Country | Sudan |
| Whyte | 4-6-2 |
| Number in Class | 9 |
| Road Numbers | |
| Gauge | 3'6" |
| Number Built | 9 |
| Builder | North British |
| Year | 1911 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 10 / 3.05 |
| Engine Wheelbase (ft / m) | 25.75 / 7.85 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.39 |
| Overall Wheelbase (engine & tender) (ft / m) | 52.67 / 16.05 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 75,824 / 34,393 |
| Engine Weight (lbs / kg) | 121,072 / 54,917 |
| Tender Loaded Weight (lbs / kg) | 102,704 / 46,586 |
| Total Engine and Tender Weight (lbs / kg) | 223,776 / 101,503 |
| Tender Water Capacity (gals / ML) | 4800 / 18.18 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 8 / 7 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 42 / 21 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 54 / 1372 |
| Boiler Pressure (psi / kPa) | 180 / 1240 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18" x 24" / 457x610 |
| Tractive Effort (lbs / kg) | 22,032 / 9993.56 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.44 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 100 - 2" / 51 |
| Flues (number - dia) (in / mm) | 14 - 5" / 127 |
| Flue/Tube length (ft / m) | 15.98 / 4.87 |
| Firebox Area (sq ft / m2) | 110.58 / 10.27 |
| Grate Area (sq ft / m2) | 22.54 / 2.09 |
| Evaporative Heating Surface (sq ft / m2) | 1240 / 115.20 |
| Superheating Surface (sq ft / m2) | 292 / 27.13 |
| Combined Heating Surface (sq ft / m2) | 1532 / 142.33 |
| Evaporative Heating Surface/Cylinder Volume | 175.42 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 4057 |
| Same as above plus superheater percentage | 4828 |
| Same as above but substitute firebox area for grate area | 23,686 |
| Power L1 | 10,132 |
| Power MT | 883.78 |