Data from Soo Miscellaneous Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.
Locobase 16533 shows the original cross-compounds delivered in 1907. Both cylinders had 26" strokes; the HP cylinder diameter measured 22", the LP a lusty 35" across.
After their conversions, the class served the Soo for decades. Aside from the 808, which was scrapped in 1940, the Js ran into the late 1940s with the 803 lingering until July 1956.
Data from "Prairie Compound Locomotive for the Soo Line", Daily Railway Age, Volume XLIII [43], No. 23b (13 June 1907), p. 932-933. Works numbers were 42642-42651 in March 1907.
These were the only Prairies to be bought by the Soo and they were pretty rare birds. They arrived as cross-compounds, which DRA reported had enjoyed considerable success on the railway in both freight and passenger service. Until this purchase, 65 cross-compound Moguls (2-6-0) such as the D-2 (Locobases 11170 and 16376) had hauled fast freights, but were needed more on the passenger trains despite the 8" (203 mm) smaller driver diameter . (Such a change suggests how modest Soo passenger trains were in size and speed.) Placing a trailing truck under the firebox allowed for longer tubes that increased boiler capacity.
Compounded on the Schenectady principle, the high-pressure cylinder sat on the left side and used a 12" (305 mm) piston valve to admit steam. The large low-pressure cylinder was attached to the right side and used Allen-Richardson balanced slide valves. A slight variation in equalizing drivers and trucks had the front and main drivers equalized with the front truck and the rear drivers compensated with the rear truck.
As usual, these two-cylinder compounds soon were converted to simple-expansion engines; see Locobase 8741.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | J | J |
Locobase ID | 8741 | 16533 |
Railroad | Minneapolis, St Paul & Sault Ste Marie (Soo) | Minneapolis, St Paul & Sault Ste Marie (Soo) |
Country | USA | USA |
Whyte | 2-6-2 | 2-6-2 |
Number in Class | 10 | 10 |
Road Numbers | 800-809 | 800-809 |
Gauge | Std | Std |
Number Built | 10 | |
Builder | Soo | Alco-Schenectady |
Year | 1907 | |
Valve Gear | Stephenson | Stephenson |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 11.33 / 3.45 | 11.33 / 3.45 |
Engine Wheelbase (ft / m) | 20.25 / 6.17 | 29.25 / 8.92 |
Ratio of driving wheelbase to overall engine wheelbase | 0.56 | 0.39 |
Overall Wheelbase (engine & tender) (ft / m) | 55.67 / 16.97 | 56 / 17.07 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 48,760 / 22,117 | |
Weight on Drivers (lbs / kg) | 132,760 / 60,219 | 133,000 / 60,328 |
Engine Weight (lbs / kg) | 181,320 / 82,245 | 191,300 / 86,772 |
Tender Loaded Weight (lbs / kg) | 128,810 / 58,427 | 118,000 / 53,524 |
Total Engine and Tender Weight (lbs / kg) | 310,130 / 140,672 | 309,300 / 140,296 |
Tender Water Capacity (gals / ML) | 6000 / 22.73 | 6000 / 22.73 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 10 / 9 | 10 / 9 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 74 / 37 | 74 / 37 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 63 / 1600 | 63 / 1600 |
Boiler Pressure (psi / kPa) | 185 / 1280 | 200 / 1380 |
High Pressure Cylinders (dia x stroke) (in / mm) | 22.5" x 26" / 572x660 | 22.5" x 26" / 572x660 (1) |
Low Pressure Cylinders (dia x stroke) (in / mm) | 35" x 26" / 889x660 (1) | |
Tractive Effort (lbs / kg) | 32,854 / 14902.34 | 25,132 / 11399.70 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.04 | 5.29 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 143 - 2" / 51 | 266 - 2" / 51 |
Flues (number - dia) (in / mm) | 21 - 5.375" / 137 | |
Flue/Tube length (ft / m) | 15 / 4.57 | 15 / 4.57 |
Firebox Area (sq ft / m2) | 165 / 15.33 | 165 / 15.33 |
Grate Area (sq ft / m2) | 38.36 / 3.57 | 38.36 / 3.56 |
Evaporative Heating Surface (sq ft / m2) | 1716 / 159.48 | 2244 / 208.47 |
Superheating Surface (sq ft / m2) | 347 / 32.25 | |
Combined Heating Surface (sq ft / m2) | 2063 / 191.73 | 2244 / 208.47 |
Evaporative Heating Surface/Cylinder Volume | 143.36 | 375.01 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 7097 | 7672 |
Same as above plus superheater percentage | 8303 | 7672 |
Same as above but substitute firebox area for grate area | 35,714 | 33,000 |
Power L1 | 9192 | 4452 |
Power MT | 457.93 | 221.39 |