Valley & Siletz 2-6-2 "Prairie" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 50 (Locobase 14318)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 52, p. 402. See also Linda Carlson, Company Towns of the Pacific Northwest (University of Washington Press, 2003). (Thanks to Chris Hohl for his 22 February 2015 email supplying the tender's fuel capacity.) Works number was 41379 in May 1914.

This 40-mile common carrier southwest of Salem, Ore, was incorporated in January 1912. Linking the Siletz River with the much larger Wilamette, the line eventually linked Independence with Valsetz at the end of the line. Its alignment required many bridges, but still included 2 1/2% grades and 16 degree curves. This logging Prairie was delivered as a wood-burner with a 3 1/2-cord fuel capacity in the tender, but was also designed to be converted to oil burning.

The V&S moved timber and agricultural products on 56 lb/yard (28 kg/metre) rail as well as serving a highly prized passenger function in the early days. "In Valsetz," says Linda Carlson (p. 123), "the Valley & Siletz Railroad wasn't the only way out, but for years it was the best; the unpaved road to camp was a rough series of 130 switchbacks that could be impassable with snow and mud." As late as 1941, the road was still notorious for its unsuitability for any normal use.

The 50 remained on the V&S until it was scrapped in 1953.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID14,318
RailroadValley & Siletz
Number in Class1
Road Numbers50
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)10.25 / 3.12
Engine Wheelbase (ft / m)26.83 / 8.18
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender) (ft / m)50.54 / 15.40
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)92,400 / 41,912
Engine Weight (lbs / kg)120,800 / 54,794
Tender Loaded Weight (lbs / kg)80,000 / 36,287
Total Engine and Tender Weight (lbs / kg)200,800 / 91,081
Tender Water Capacity (gals / ML)4000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)51 / 25.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)46 / 1168
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)17" x 24" / 432x610
Tractive Effort (lbs / kg)23,070 / 10464.39
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.01
Heating Ability
Firebox Area (sq ft / m2)121 / 11.24
Grate Area (sq ft / m2)18.20 / 1.69
Evaporative Heating Surface (sq ft / m2)1552 / 144.18
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1552 / 144.18
Evaporative Heating Surface/Cylinder Volume246.15
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3276
Same as above plus superheater percentage3276
Same as above but substitute firebox area for grate area21,780
Power L14721
Power MT337.92

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Wes Barris