South San Francisco Beltline 2-4-4 Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 13706)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 36, p. 99 Works number was 34845 in June 1910.

This powerful little oil-burning tank served the SSFB transfer line for years on its 70-lb/yard (35-kg/metre) rail before moving on to Algoma Lumber. Algoma sold the engine to the Modesto & Empire Traction Company in July 1942 as their #8. Nicknamed "Jeep", the 8 gave good wartime service before being scrapped in 1948.

Specifications by Steve Llanso of Sweat House Media
Locobase ID13,706
RailroadSouth San Francisco Beltline
Number in Class1
Road Numbers4
Number Built1
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft) 7.50
Engine Wheelbase (ft)28.58
Ratio of driving wheelbase to overall engine wheebase 0.26
Overall Wheelbase (engine & tender) (ft)28.58
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)75,000
Engine Weight (lbs)110,000
Tender Loaded Weight (lbs)
Total Engine and Tender Weight (lbs)110,000
Tender Water Capacity (gals)1600
Tender Fuel Capacity (oil/coal) (gals/tons)800
Minimum weight of rail (calculated) (lb/yd)
Geometry Relating to Tractive Effort
Driver Diameter (in)46
Boiler Pressure (psi)160
High Pressure Cylinders (dia x stroke) (in)16" x 24"
Tractive Effort (lbs)18,165
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.13
Heating Ability
Firebox Area (sq ft)88.50
Grate Area (sq ft)15
Evaporative Heating Surface (sq ft)1068
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)1068
Evaporative Heating Surface/Cylinder Volume191.22
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2400
Same as above plus superheater percentage2400
Same as above but substitute firebox area for grate area14,160
Power L13318
Power MT

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