Data from "0-8-4 Superheater Locomotive, Great Indian Peninsula Ry," The Locomotive Magazine, Vol XXI [21], No 273 (15 May 1915).
Locobase 6746 shows some 2-8-4Ts delivered to run on the Ghat incline in 1906. The engines delivered several years later were very similar, but the 40 and her sisters featured several key differences. Although possessing the same Belpaire firebox dimensions, the new design traded some of their evaporative heating surface area for an almost equal amount of superheater area.
Thus the new boilers had an impressive ratio of superheater to combined heating surface area. More cylinder volume and hotter, drier steam undoubtedly provided a considerable boost in available power.
Another key change was the deletion of the lead guiding axle. The LM entry doesn't say why the truck was eliminated, so Locobase can only guess that the railway wanted to reduce overall wheelbase. Certainly the right of way was substantial enough as the four adhesive axles now supported 15 more short tons of weight.
Locobase also can't say how many of these 0-8-4Ts were produced.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Y1 |
| Locobase ID | 20436 |
| Railroad | Great Indian Peninsula (GIPR) |
| Country | India |
| Whyte | 0-8-4T |
| Number in Class | |
| Road Numbers | 40 |
| Gauge | 5'6" |
| Number Built | |
| Builder | North British |
| Year | 1910 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 15.50 / 4.72 |
| Engine Wheelbase (ft / m) | 28.33 / 8.63 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.55 |
| Overall Wheelbase (engine & tender) (ft / m) | 28.33 / 8.63 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 36,064 / 16,358 |
| Weight on Drivers (lbs / kg) | 176,048 / 79,854 |
| Engine Weight (lbs / kg) | 228,592 / 103,688 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 3000 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 73 / 36.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 51 / 1295 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 22" x 26" / 559x660 |
| Tractive Effort (lbs / kg) | 33,557 / 15221.22 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.25 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 12.50 / 3.81 |
| Firebox Area (sq ft / m2) | 172 / 15.98 |
| Grate Area (sq ft / m2) | 32 / 2.97 |
| Evaporative Heating Surface (sq ft / m2) | 1552 / 144.19 |
| Superheating Surface (sq ft / m2) | 436 / 40.51 |
| Combined Heating Surface (sq ft / m2) | 1988 / 184.70 |
| Evaporative Heating Surface/Cylinder Volume | 135.67 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 5120 |
| Same as above plus superheater percentage | 6246 |
| Same as above but substitute firebox area for grate area | 33,574 |
| Power L1 | 7533 |
| Power MT | 377.34 |