Data from "Diag[ram] 7B, IRS 5' 6" 2-8-2 Shunting Heavy Locomotive" supplied by Vinoo Mathur 27 November 2020 post in his Rail Enthusiast series at [], last accessed 3 November 2025; See also S. Shankar of India's National Rail Museum website -- [] -- and "Indian Railways classes XG and XG/M", Loco-info.com at [], last accessed 5 April 2026.
Originally delivered as an 0-8-0 heavy shunter (Locobase 4268) aspart of a series of Indian Railway Standard designs created in the mid-1920s to meet Indian railway equirements, these engines operated as heavy switchers (hump shunters) on the North Western Railway of India. XG signified the the larger of two all-adhesion eight-coupled IRS freight designs. MLS superheater, multi-valve regulator type header.
But as built, their weight caused so much damage to the track that they were converted to a 2-8-2 arrangement in 1943. Adding the two carrying axles spread the weight, reducing the weight per foot of adhesion wheelbase by 28% and weight per foot of engine wheelbase from 13,437 lb (6,095 kg) to 7,429 lb (3,370 kg).
[] notes that these had "...a wider firebox and other improvements to handle low-grade coal."
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | IRS/XG.M |
| Locobase ID | 21328 |
| Railroad | North Western |
| Country | India |
| Whyte | 2-8-2 |
| Number in Class | 3 |
| Road Numbers | 911-913 |
| Gauge | 5'6" |
| Number Built | |
| Builder | Indian State |
| Year | 1943 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 15.17 / 4.62 |
| Engine Wheelbase (ft / m) | 29.92 / 9.12 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.51 |
| Overall Wheelbase (engine & tender) (ft / m) | 59.50 / 18.14 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 42,448 / 19,254 |
| Weight on Drivers (lbs / kg) | 158,928 / 72,089 |
| Engine Weight (lbs / kg) | 222,282 / 100,826 |
| Tender Loaded Weight (lbs / kg) | 140,918 / 63,919 |
| Total Engine and Tender Weight (lbs / kg) | 363,200 / 164,745 |
| Tender Water Capacity (gals / ML) | 5400 / 20.45 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 8.80 / 8 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 66 / 33 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 51 / 1295 |
| Boiler Pressure (psi / kPa) | 150 / 1020 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 23.5" x 28" / 597x711 |
| Tractive Effort (lbs / kg) | 38,658 / 17534.99 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.11 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 150 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 36 - 5.25" / 133 |
| Flue/Tube length (ft / m) | 16.50 / 5.03 |
| Firebox Area (sq ft / m2) | 186 / 17.28 |
| Grate Area (sq ft / m2) | 41.50 / 3.86 |
| Evaporative Heating Surface (sq ft / m2) | 2453 / 227.89 |
| Superheating Surface (sq ft / m2) | 605 / 56.21 |
| Combined Heating Surface (sq ft / m2) | 3058 / 284.10 |
| Evaporative Heating Surface/Cylinder Volume | 174.51 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 6225 |
| Same as above plus superheater percentage | 7470 |
| Same as above but substitute firebox area for grate area | 33,480 |
| Power L1 | 8008 |
| Power MT | 444.34 |