Yosemite Valley 4-4-0 "American" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 22 (Locobase 11369)

Data from "Equipment and Supplies: Locomotive Building, Railway Age Gazette, Vol XLII, no 14 (5 April 1907), p. 498 and the YVRR history website at [] . Works numbers were 43167 and 44389. Purchase prices were $13,589.42 and $14,734.99

This pair was the modern passenger power for the YVRR. They had a small grate for the boiler, which suggests that they didn't have to run far on any particular service. The website's photos shows the very short trains these engines would haul. And they were suitable for as long as rail passenger service could compete with buses or cars in the Yosemite Valley.

NB: The direct heating surface (including the firebox heating surface) is an estimate calculated by subtracting the calculated tube heating surface from the reported total evaporative heating surface.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID11369
RailroadYosemite Valley
Number in Class1
Road Numbers22-23
Number Built1
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)72,000 / 32,659
Engine Weight (lbs / kg)110,000 / 49,895
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)4000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2250 / 8516
Minimum weight of rail (calculated) (lb/yd / kg/m)60 / 30
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 1600
Boiler Pressure (psi / kPa)165 / 11.40
High Pressure Cylinders (dia x stroke) (in / mm)18" x 26" / 457x660
Tractive Effort (lbs / kg)18,753 / 8506.23
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.84
Heating Ability
Tubes (number - dia) (in / mm)265 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)11 / 3.35
Firebox Area (sq ft / m2)182 / 16.91
Grate Area (sq ft / m2)17 / 1.58
Evaporative Heating Surface (sq ft / m2)1700 / 157.99
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1700 / 157.99
Evaporative Heating Surface/Cylinder Volume221.93
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2805
Same as above plus superheater percentage2805
Same as above but substitute firebox area for grate area30,030
Power L15903
Power MT361.50

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