Data from Wiener (1930) and DeGolyer, Volume 72, pp. 303+. See also "Articulated Locomotive Tests in India and Burma", Railway Engineer, Volume 46, No.11 (November 1925), pp. 399-402. Works number was 56380 in April 1923.
This low-drivered Mallet was bought for comparison with the Garratts the railroad already had in service. Wiener, who described them only in the plural, states that their role was to haul 640-ton trains between Sibi and Kolpur, replacing two rigid-wheelbase locomotives. The engine operated alone over the 1.8% grades between Sibi and Abigum. The line then steepened on its way to Mach, reaching a 3% pitch at points. Here the Mallet had one helper. Finally, on the 4% grades between Mach and Abigum, the railroad tacked on another helper.
The photograph shows an orthodox Mallet with LP leading well ahead of the smokebox door, coned boiler and small domes, and a long Belpaire firebox which had 33 sq ft (3.05 sq m) of arch tubes and a Gaines combustion chamber. In a concession to British preferences, the firebox was made of copper. The HP cylinder valves measured 10" (254 mm) while the LP valves had diameters of 12" (306 mm).
Neither the Mallet nor the Garratt proved satisfactory and 2-10-0s replaced them both.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | unknown |
| Locobase ID | 3555 |
| Railroad | North Western Railways |
| Country | India |
| Whyte | 2-6-6-2 |
| Number in Class | |
| Road Numbers | |
| Gauge | 5'6" |
| Number Built | |
| Builder | Baldwin |
| Year | 1923 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 28.84 / 8.79 |
| Engine Wheelbase (ft / m) | 44.32 / 13.51 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.65 |
| Overall Wheelbase (engine & tender) (ft / m) | 72.70 / 22.16 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 39,200 / 17,781 |
| Weight on Drivers (lbs / kg) | 235,000 / 106,594 |
| Engine Weight (lbs / kg) | 274,000 / 124,284 |
| Tender Loaded Weight (lbs / kg) | 147,400 / 66,860 |
| Total Engine and Tender Weight (lbs / kg) | 421,400 / 191,144 |
| Tender Water Capacity (gals / ML) | 7560 / 28.64 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 10 / 9 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 65 / 32.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 52 / 1321 |
| Boiler Pressure (psi / kPa) | 213.20 / 1470 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 19.02" x 30" / 483x762 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 29.76" x 30" / 756x762 |
| Tractive Effort (lbs / kg) | 53,707 / 24361.11 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.38 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 217 - 2" / 51 |
| Flues (number - dia) (in / mm) | 35 - 5.375" / 137 |
| Flue/Tube length (ft / m) | 18 / 5.49 |
| Firebox Area (sq ft / m2) | 265.98 / 24.71 |
| Grate Area (sq ft / m2) | 56.30 / 5.23 |
| Evaporative Heating Surface (sq ft / m2) | 3176 / 295.06 |
| Superheating Surface (sq ft / m2) | 708 / 65.77 |
| Combined Heating Surface (sq ft / m2) | 3884 / 360.83 |
| Evaporative Heating Surface/Cylinder Volume | 321.93 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 12,003 |
| Same as above plus superheater percentage | 14,164 |
| Same as above but substitute firebox area for grate area | 66,914 |
| Power L1 | 8322 |
| Power MT | 468.43 |