Uintah Railway 2-8-2 "Mikado" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 30 (Locobase 13815)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 39, p. 44; and Uintah Railway Assorted Steam Locomotive diagrams supplied in August 2013 by Allen Stanley from his extensive Rail Data Exchange. See Locobase 12801 for a short history of the Uintah. Works number was 36908 in 1911.

This Mikado was fated to spend its entire career battling grades of 4-6 1/2% (according to the specs) and curves with radii of 30-degrees (103 feet/31.4 metres). Uintah historians claim that the last 5 miles up to Baxter Pass, fully 8,400 feet above sea level and more, ran at a steady 7 1/2% incline. Also, as this was the alkaline desert, railside observers could see the 40 roll by trailing its tender and 3-4 special water cars. (The desert stretches on the South African Railways led to similar innovations.)

When the Uintah was closed and abandoned in 1939, the 40 went to the ferro-knacker.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID13,815
RailroadUintah Railway
Number in Class1
Road Numbers30
Number Built1
Valve GearVariable cut-off
Locomotive Length and Weight
Driver Wheelbase (ft / m)11.67 / 3.56
Engine Wheelbase (ft / m)26 / 7.92
Ratio of driving wheelbase to overall engine wheebase 0.45
Overall Wheelbase (engine & tender) (ft / m)44.67 / 13.62
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)120,000 / 54,431
Engine Weight (lbs / kg)146,000 / 66,225
Tender Loaded Weight (lbs / kg)100,000 / 45,359
Total Engine and Tender Weight (lbs / kg)246,000 / 111,584
Tender Water Capacity (gals / ML)5000 / 18.94
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)5 / 4.50
Minimum weight of rail (calculated) (lb/yd / kg/m)50 / 25
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)40 / 1016
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)19" x 22" / 483x559
Tractive Effort (lbs / kg)30,378 / 13779.25
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.95
Heating Ability
Firebox Area (sq ft / m2)122 / 11.33
Grate Area (sq ft / m2)32 / 2.97
Evaporative Heating Surface (sq ft / m2)2336 / 217.02
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2336 / 217.02
Evaporative Heating Surface/Cylinder Volume323.57
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5760
Same as above plus superheater percentage5760
Same as above but substitute firebox area for grate area21,960
Power L14897
Power MT359.87

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