Sumpter Valley 4-6-0 "Ten-Wheeler" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 50 (Locobase 12506)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 51, p. 357. (Thanks to Chris Hohl for his 11 March 2016 email noting the tender's fuel capacity.) Works number was 42865 in February 1916.

This Ten-wheeler 's tender carried 3 1/2 cords of wood. The DeWitt Museum's Facebook page ([], last visited 4 April 2016) says that the cabbage-stacked 50 "was mainly used for the passenger line and had multiple wrecks."

The 50 retired in 1941, sold to locomotive rebuilder/reseller Dulien Steel Products. Dulien sold the 50 to Peru's Cuzco as their 125.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID12,506
RailroadSumpter Valley
Number in Class1
Road Numbers50
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)11 / 3.35
Engine Wheelbase (ft / m)20.33 / 6.20
Ratio of driving wheelbase to overall engine wheebase 0.54
Overall Wheelbase (engine & tender) (ft / m)48.10 / 14.66
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)72,000 / 32,659
Engine Weight (lbs / kg)91,000 / 41,277
Tender Loaded Weight (lbs / kg)80,000 / 36,287
Total Engine and Tender Weight (lbs / kg)171,000 / 77,564
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)40 / 20
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)41 / 1118
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)16" x 20" / 406x508
Tractive Effort (lbs / kg)19,106 / 8666.35
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.77
Heating Ability
Firebox Area (sq ft / m2)111 / 10.32
Grate Area (sq ft / m2)14.20 / 1.32
Evaporative Heating Surface (sq ft / m2)1411 / 131.13
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1411 / 131.13
Evaporative Heating Surface/Cylinder Volume303.17
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2556
Same as above plus superheater percentage2556
Same as above but substitute firebox area for grate area19,980
Power L15196
Power MT477.30

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Wes Barris