Sumpter Valley 4-6-0 "Ten-wheeler" Locomotives of 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.

Specifications 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)11
Engine Wheelbase (ft)20.33
Ratio of driving wheelbase to overall engine wheebase 0.54
Overall Wheelbase (engine & tender) (ft)48.10
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)72,000
Engine Weight (lbs)91,000
Tender Loaded Weight (lbs)80,000
Total Engine and Tender Weight (lbs)171,000
Tender Water Capacity (gals)4000
Tender Fuel Capacity (oil/coal) (gals/tons)
Minimum weight of rail (calculated) (lb/yd)40
Geometry Relating to Tractive Effort
Driver Diameter (in)41
Boiler Pressure (psi)180
High Pressure Cylinders (dia x stroke) (in)16" x 20"
Tractive Effort (lbs)19,106
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.77
Heating Ability
Firebox Area (sq ft)111
Grate Area (sq ft)14.20
Evaporative Heating Surface (sq ft)1411
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)1411
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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