Butte, Anaconda & Pacific 2-8-0 "Consolidation" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 25 / F-12 (Locobase 8833)

Data from GN 1916 locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

The B A & P was built by Marcus Daly in 1892 to move the copper from his Butte-area mines over 26 miles of 75-lb track to the big smelter at Anaconda. The quartet of Consolidations in this entry helped move that ore until 1913, when the Biggest Little Railroad in the World electrified.

Soon after their supercession, 26 & 27 were bought by the Great Northern, classed F-12 and renumbered. Light-footed, low-drivered, and quite powerful for their size, the pair served the GN into the 1940s.

Specifications by Steve Llanso of Sweat House Media
Class25 / F-12
Locobase ID8833
RailroadButte, Anaconda & Pacific
Number in Class4
Road Numbers25-28 / 1326-1327
Number Built4
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase14.50'
Engine Wheelbase22.25'
Ratio of driving wheelbase to overall engine wheebase 0.65
Overall Wheelbase (engine & tender)54.67'
Axle Loading (Maximum Weight per Axle)41750 lbs
Weight on Drivers167000 lbs
Engine Weight186000 lbs
Tender Light Weight122000 lbs
Total Engine and Tender Weight308000 lbs
Tender Water Capacity6000 gals
Tender Fuel Capacity (oil/coal)12 tons
Minimum weight of rail (calculated)70 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter52"
Boiler Pressure200 psi
Cylinders (dia x stroke)21" x 28"
Tractive Effort40368 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.14
Heating Ability
Firebox Area180 sq. ft
Grate Area46 sq. ft
Evaporative Heating Surface2579 sq. ft
Superheating Surface
Combined Heating Surface2579 sq. ft
Evaporative Heating Surface/Cylinder Volume229.76
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9200
Same as above plus superheater percentage9200
Same as above but substitute firebox area for grate area36000
Power L15372
Power MT283.67

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