Zuni Mountain 2-8-0 "Consolidation" Locomotives in 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.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID13,249
RailroadZuni Mountain
Number in Class1
Road Numbers12
Number Built1
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.25 / 4.34
Engine Wheelbase (ft / m)22.33 / 6.81
Ratio of driving wheelbase to overall engine wheebase 0.64
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)150,000 / 68,039
Engine Weight (lbs / kg)167,000 / 75,750
Tender Loaded Weight (lbs / kg)60,000 / 27,216
Total Engine and Tender Weight (lbs / kg)227,000 / 102,966
Tender Water Capacity (gals / ML)3000 / 11.36
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT) 4.50 / 4.10
Minimum weight of rail (calculated) (lb/yd / kg/m)63 / 31.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)50 / 1270
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)21" x 26" / 533x660
Tractive Effort (lbs / kg)35,086 / 15914.76
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.28
Heating Ability
Firebox Area (sq ft / m2)195 / 18.12
Grate Area (sq ft / m2)32.60 / 3.03
Evaporative Heating Surface (sq ft / m2)2719 / 252.60
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2719 / 252.60
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 area35,100
Power L15316
Power MT312.53

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