Data from 1947 CP Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for filling in the valve gear ID.)
This small class of Decapods constituted conversions from the CP's 0-6-6-0s of 1911 (Locobases 3569 and 15025).. Even though there were only six locomotives, they made up three subclasses based on the number of 2 1/4" tubes in the boiler. The one R2a had 156 (for a total of 2,405 sq ft EHS including the 22 flues all 3 classes had), the 4 R2bs had 151 as shown in the specs, and the R1c had 167 tubes. This last locomotive also had slightly more firebox heating surface (221 sq ft vs 216 sq ft) for a total of 2,525 sq ft EHS.
Small they were with small boilers, but the CP ran them into the late 1950s.
Data from 1947 CP Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for filling in the valve gear ID.)
These oil-burning Decapods came out of the Angus shops in four subclasses. They reflected the CP's study of the R2 conversions (see Locobase 4529) and were very similar in size and power.
R3a (2 units in May and June 1917), R3b (1 in August, 3 in September, 1 in January 1918), and R3c (18 units in January to June 1918) all had the same boiler dimensions. The 10 R3d (1 in June, 3 in July, 2 August, and 2 each in January-February 1919) had slightly more firebox area (230 sq ft vs 221).
The big difference among the sub-classes seems to have been the size of the journal bearings on the driving axle (the 3rd of 5). The b had 10 1/2" by 21" while the c and d had 11" diameter journals. And between the R3a and R3b were a host of materials differences such as the use of mild steel in the place of cast iron in some cases and cast steel instead of wrot iron in others.
Like the R2s, these small, low-drivered Deks ran for decades, only being retired in 1956 through 1965.
| Principal Dimensions by Steve Llanso of Middle Run Media | ||
|---|---|---|
| Class | R2a/R2b/R2c | R3a/R3b/R3c/R3d |
| Locobase ID | 4529 | 4530 |
| Railroad | Canadian Pacific (CPR) | Canadian Pacific (CPR) |
| Country | Canada | Canada |
| Whyte | 2-10-0 | 2-10-0 |
| Number in Class | 6 | 35 |
| Road Numbers | 5750-5755 | 5756-5790 |
| Gauge | Std | Std |
| Number Built | 35 | |
| Builder | Canadian Pacific | Canadian Pacific |
| Year | 1916 | 1917 |
| Valve Gear | Walschaert | Walschaert |
| Locomotive Length and Weight | ||
| Driver Wheelbase (ft / m) | 20.66 / 6.30 | 22 / 6.71 |
| Engine Wheelbase (ft / m) | 29.79 / 9.08 | 31.12 / 9.49 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.69 | 0.71 |
| Overall Wheelbase (engine & tender) (ft / m) | 61.82 / 18.84 | 61.76 / 18.82 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | ||
| Weight on Drivers (lbs / kg) | 227,500 / 103,192 | 234,000 / 106,141 |
| Engine Weight (lbs / kg) | 247,500 / 112,264 | 262,000 / 118,841 |
| Tender Loaded Weight (lbs / kg) | 139,000 / 63,049 | 188,000 / 85,275 |
| Total Engine and Tender Weight (lbs / kg) | 386,500 / 175,313 | 450,000 / 204,116 |
| Tender Water Capacity (gals / ML) | 6000 / 22.73 | 9360 / 35.45 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 12 / 11 | 3360 / 12,718 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 76 / 38 | 78 / 39 |
| Geometry Relating to Tractive Effort | ||
| Driver Diameter (in / mm) | 58 / 1473 | 58 / 1473 |
| Boiler Pressure (psi / kPa) | 200 / 1380 | 200 / 1380 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 23.5" x 32" / 597x813 | 24" x 32" / 610x813 |
| Tractive Effort (lbs / kg) | 51,797 / 23494.75 | 54,025 / 24505.36 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.39 | 4.33 |
| Heating Ability | ||
| Tubes (number - dia) (in / mm) | 151 - 2.25" / 57 | 145 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 22 - 5.25" / 133 | 28 - 5.5" / 140 |
| Flue/Tube length (ft / m) | 18.59 / 5.67 | 19.09 / 5.82 |
| Firebox Area (sq ft / m2) | 216 / 20.07 | 221 / 20.53 |
| Grate Area (sq ft / m2) | 59 / 5.48 | 59 / 5.48 |
| Evaporative Heating Surface (sq ft / m2) | 2566 / 238.48 | 2621 / 243.59 |
| Superheating Surface (sq ft / m2) | 410 / 38.10 | 628 / 58.36 |
| Combined Heating Surface (sq ft / m2) | 2976 / 276.58 | 3249 / 301.95 |
| Evaporative Heating Surface/Cylinder Volume | 159.78 | 156.38 |
| Computations Relating to Power Output (More Information) | ||
| Robert LeMassena's Power Computation | 11,800 | 11,800 |
| Same as above plus superheater percentage | 13,452 | 14,042 |
| Same as above but substitute firebox area for grate area | 49,248 | 52,598 |
| Power L1 | 8831 | 10,818 |
| Power MT | 427.89 | 509.61 |