Columbia River Belt Line 2-6-2 "Prairie" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class Siwash (Locobase 11059)

Data from "Oil-Burning Locomotives", Record of Recent Construction #57 (Baldwin Locomotive Works, 1911), p. 7. See also DeGolyer, Volume 39, p. 27. Works number was 36570 was in May 1911.

This logger operated in Oregon, first for the CRBL - headquartered in Blind Slough, Ore --, then for Larkins Green Lumber Company. Baldwin's specs required the engine to scale 8% grades, negotiate 50-deg curves on relatively robust 60-lb/yard (30-kg/metre) rails. The tight curvatures meant that both trucks were allowed a generous 6 1/4 inches of traverse to each side.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID11,059
RailroadColumbia River Belt Line
Number in Class1
Road Numbers
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)9 / 2.74
Engine Wheelbase (ft / m)23.50 / 7.16
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender) (ft / m)23.50 / 7.16
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)85,400 / 38,737
Engine Weight (lbs / kg)119,600 / 54,250
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)119,600
Tender Water Capacity (gals / ML)1200 / 4.55
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)450 / 1.70
Minimum weight of rail (calculated) (lb/yd / kg/m)47 / 23.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)44 / 1118
Boiler Pressure (psi / kPa)165 / 11.40
High Pressure Cylinders (dia x stroke) (in / mm)17" x 22" / 432x559
Tractive Effort (lbs / kg)20,266 / 9192.51
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.21
Heating Ability
Firebox Area (sq ft / m2)93 / 8.64
Grate Area (sq ft / m2)14.40 / 1.34
Evaporative Heating Surface (sq ft / m2)1282 / 119.14
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1282 / 119.14
Evaporative Heating Surface/Cylinder Volume221.82
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2376
Same as above plus superheater percentage2376
Same as above but substitute firebox area for grate area15,345
Power L13657
Power MT283.22

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Wes Barris