Crown Willamette Paper Co. 2-6-6-2 "Mallet Mogul" Locomotives in the USA
Class Details by Steve Llanso of Sweat House Media
Class 12 (Locobase 4055)
Data from Jon Davis's [
], supplemented by DeGolyer, Vol 80, pp. 266+. Works number was 60771 in April 1929.
One of several Prairie Mallet tanks built by Baldwin for Northwest logging roads with split saddle tank (called "semi-saddle" in the specifications). Like most of the other tanks of this layout, the HP valves were supplied through 8" (203 mm) piston valves, the LP cylinders through 12" (305 mm) piston valves.
12 worked for 35 years for the same company out of Cathlamet, Wash. She was scrapped after her 1959 retirement.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 12 |
| Locobase ID | 4055 |
| Railroad | Crown Willamette Paper Co. |
| Country | USA |
| Whyte | 2-6-6-2T |
| Number in Class | 1 |
| Road Numbers | 12 |
| Gauge | Std |
| Number Built | 1 |
| Builder | Baldwin |
| Year | 1929 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 16 / 4.88 |
| Engine Wheelbase (ft / m) | 37.25 / 11.35 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.43 |
| Overall Wheelbase (engine & tender) (ft / m) | 37.25 / 11.35 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 183,000 / 83,008 |
| Engine Weight (lbs / kg) | 222,000 / 100,698 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 2500 / 9.47 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 1200 / 4542 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 51 / 25.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 44 / 1118 |
| Boiler Pressure (psi / kPa) | 200 / 1380 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 24" / 406x610 |
| Low Pressure Cylinders (dia x stroke) (in / mm) | 26" x 24" / 660x610 |
| Tractive Effort (lbs / kg) | 34,436 / 15619.93 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.31 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 124 - 2" / 51 |
| Flues (number - dia) (in / mm) | 18 - 5.375" / 137 |
| Flue/Tube length (ft / m) | 17 / 5.18 |
| Firebox Area (sq ft / m2) | 128 / 11.89 |
| Grate Area (sq ft / m2) | 26.20 / 2.43 |
| Evaporative Heating Surface (sq ft / m2) | 1654 / 153.72 |
| Superheating Surface (sq ft / m2) | 358 / 33.27 |
| Combined Heating Surface (sq ft / m2) | 2012 / 186.99 |
| Evaporative Heating Surface/Cylinder Volume | 296.31 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 5240 |
| Same as above plus superheater percentage | 6183 |
| Same as above but substitute firebox area for grate area | 30,208 |
| Power L1 | 5486 |
| Power MT | 396.54 |