Central Pacific 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class S-1 (Locobase 2846)

Master Mechanic AJ Stevens designed this engine for the heavy suburban traffic out of Oakland, Calif. Note the very high factor of adhesion, which suggests an underexploited boiler.

(Alexander, Iron Horse, pl 76). According to http://www.tidewatersouthern.com/contents/motivepower/steam/262T11/262t11.htm (visited 6 Jan 2005), this class of little tanks operated into the 'Teens. One (335, works #18) was sold to the Tidewater Southern in 1912, which operated it between Modesto and the Stanilaus River and later to Stockton until the TS was electrified. At that point, the TS sold it to the Howard Terminal in Oakland in 1917.

Specifications by Steve Llanso of Sweat House Media
Locobase ID2846
RailroadCentral Pacific
Number in Class7
Road Numbers230-236
Number Built7
Valve Gear
Locomotive Length and Weight
Driver Wheelbase14'
Engine Wheelbase28'
Ratio of driving wheelbase to overall engine wheebase 0.50
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers80400 lbs
Engine Weight104100 lbs
Tender Light Weight
Total Engine and Tender Weight104100 lbs
Tender Water Capacity1600 gals
Tender Fuel Capacity (oil/coal)4 tons
Minimum weight of rail (calculated)45 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter51"
Boiler Pressure145 psi
Cylinders (dia x stroke)16" x 24"
Tractive Effort14848 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.41
Heating Ability
Firebox Area
Grate Area
Evaporative Heating Surface
Superheating Surface
Combined Heating Surface0
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation0
Same as above plus superheater percentage0
Same as above but substitute firebox area for grate area0
Power L10
Power MT0


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