Apache 2-8-2 "Mikado" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 300 (Locobase 14053)

Data from Baldwin Negative 7174 as digitized by the DeGolyer Library of Southern Methodist University and archived at http://digitalcollections.smu.edu/u?/rwy,324. See also Arthur R Gomez, "Industry and Indian Self-Determination: Northern Arizona's Apache Lumbering Empire, 1870-1970" in Christopher J. Huggard and Arthur R. G=mez (eds.), Forests Under Fire: A Century of Ecosystem Mismanagement in the Southwest, (University of Arizona Press, 2001), pp. 3-40. Works number was 52191 in August 1919.

As part of its overall look, this Mikado sported a big Rushton Improved cabbage stack. Its superheated boiler supplied steam to the cylinders through 12" (305 mm) piston valves. Firebox heating surface area included 24.2 sq ft (2.25 sq m) of arch tubes.

The APA was incorporated in 1917 and built its 72-mile main line Holbrook and McNary over the next 3 years, the work being completed on 1 July 1920.

The 300 served for 35 years before being sold to Southwest Lumber Mill in 1954. It was scrapped in September 1956.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID14,053
Number in Class1
Road Numbers300
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.08 / 3.99
Engine Wheelbase (ft / m)27.08 / 8.25
Ratio of driving wheelbase to overall engine wheebase 0.48
Overall Wheelbase (engine & tender) (ft / m)55.96 / 16.88
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)141,500 / 62,732
Engine Weight (lbs / kg)179,000 / 80,467
Tender Loaded Weight (lbs / kg)55,000 / 42,003
Total Engine and Tender Weight (lbs / kg)234,000 / 122,470
Tender Water Capacity (gals / ML)7000 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)10 / 7.30
Minimum weight of rail (calculated) (lb/yd / kg/m)59 / 29.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 1219
Boiler Pressure (psi / kPa)175 / 11
High Pressure Cylinders (dia x stroke) (in / mm)20.5" x 28" / 521x711
Tractive Effort (lbs / kg)36,465 / 16540.27
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.88
Heating Ability
Firebox Area (sq ft / m2)178 / 16.54
Grate Area (sq ft / m2)41.30 / 3.84
Evaporative Heating Surface (sq ft / m2)2500 / 232.34
Superheating Surface (sq ft / m2)553 / 51.39
Combined Heating Surface (sq ft / m2)3053 / 283.73
Evaporative Heating Surface/Cylinder Volume233.72
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation7228
Same as above plus superheater percentage8528
Same as above but substitute firebox area for grate area36,757
Power L110,951
Power MT682.48

All material Copyright © SteamLocomotive.com
Wes Barris