Ray & Gila Valley 2-8-2 "Mikado" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 13800)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 39, p. 13. See also "Kennecott Ray Mines Division" at [], last accessed 29 January 2012. Works number was 36824 in August 1911.

This small Arizona copper road was opened in 1910 about 120 miles southeast of Phoenix. It had two sections 12 miles apart. The longer piece connected the Ray copper mines to Ray Junction, which met the Phoenix & Eastern. The 2.66-mile linked Hayden Junction on the P & E with the smelter at Hayden.

The company was operated as a common carrier until 1943, when it was bought by Kennecott Copper and taken private. The 4 remained in service after that date.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID13,800
RailroadRay & Gila Valley
Number in Class1
Road Numbers4
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14 / 4.27
Engine Wheelbase (ft / m)31.83 / 9.70
Ratio of driving wheelbase to overall engine wheebase 0.44
Overall Wheelbase (engine & tender) (ft / m)60.42 / 18.42
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)190,000 / 86,183
Engine Weight (lbs / kg)240,000 / 108,862
Tender Loaded Weight (lbs / kg)145,000 / 65,771
Total Engine and Tender Weight (lbs / kg)385,000 / 174,633
Tender Water Capacity (gals / ML)8000 / 30.30
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)3000 / 11.40
Minimum weight of rail (calculated) (lb/yd / kg/m)79 / 39.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)50 / 1270
Boiler Pressure (psi / kPa)190 / 13.10
High Pressure Cylinders (dia x stroke) (in / mm)23" x 28" / 584x711
Tractive Effort (lbs / kg)47,843 / 21701.25
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.97
Heating Ability
Firebox Area (sq ft / m2)194 / 18.02
Grate Area (sq ft / m2)57.20 / 5.31
Evaporative Heating Surface (sq ft / m2)4027 / 374.12
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)4027 / 374.12
Evaporative Heating Surface/Cylinder Volume299.08
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,868
Same as above plus superheater percentage10,868
Same as above but substitute firebox area for grate area36,860
Power L15876
Power MT272.72

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