Zuni Mountain 2-8-0 "Consolidation" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 12 (Locobase 13249)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 31, p. 157. See also David F Myrick, New Mexico's Railroads ( : University of New Mexico Press, 1990, reprint of Colorado Railroad Museum edition, first published in 1970), p. 212. Works number was 32564 in January 1908.

About the only physical difference between this logging Consolidation and its mainline brethren was the short wheelbase, which follows a slightly shorter set of tubes. Otherwise, the 12 had good power and a relatively large boiler.

The ZM, chartered in August 1891, served the American Lumber Company in New Mexico, which logged the Zuni Mountain pine tree timber and transported the logs on 60-65 lb/yard (30-32.5 kg/metre) down to Grants, NM, where the Atlantic & Pacific took the load into Albuquerque.

The 12 was sold in 1917 to another New Mexico timber company, the McKinley Land & Lumber Company.

Specifications by Steve Llanso of Sweat House Media
Locobase ID13249
RailroadZuni Mountain
Number in Class1
Road Numbers12
Number Built1
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase14.25'
Engine Wheelbase22.33'
Ratio of driving wheelbase to overall engine wheebase 0.64
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers150000 lbs
Engine Weight167000 lbs
Tender Light Weight60000 lbs
Total Engine and Tender Weight227000 lbs
Tender Water Capacity3000 gals
Tender Fuel Capacity (oil/coal)4.5 tons
Minimum weight of rail (calculated)63 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter50"
Boiler Pressure180 psi
Cylinders (dia x stroke)21" x 26"
Tractive Effort35086 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.28
Heating Ability
Firebox Area195 sq. ft
Grate Area32.60 sq. ft
Evaporative Heating Surface2719 sq. ft
Superheating Surface
Combined Heating Surface2719 sq. ft
Evaporative Heating Surface/Cylinder Volume260.87
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5868
Same as above plus superheater percentage5868
Same as above but substitute firebox area for grate area35100
Power L15316
Power MT312.53

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