Lassen Lumber & Box 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 25 (Locobase 15222)

Data from DeGolyer Library of Southern Methodist University Baldwin Specifications, Vol 71, pp. 277+. see also the detailed description of the LL&BC operations at the "Lassen Lumber & Box", citrusmodelinggroup at Yahoo Groups (, last accessed 30 May 2013). Works number was 56403 in April 1923.

LL&BC opened two mills in Susanville, Calif in 1918. The company had recently won two big harvesting concessions from the National Forest Service in Lassen National Park that were dubbed "Norvel Flat Chance and the McCoy Chance". Total holding was an impressive 300 million feet of timber. The amount of timber under contract was later doubled.

This oil-burning logging Prairie arrived five years later as the LL&BC moved its logging headquarters from Facht to Lasco to place it closer to both the logging and the link to the Southern Pacific.

By 1930, the Red River Lumber Company railroad handled the logs and their herald appeared on 25's tender. After several more years, the RRLC sold the 25 to Modesto & Empire Traction as their 7. M&ET operated the 7 until the early 1950s before scrapping it in April 1952.

Specifications by Steve Llanso of Sweat House Media
Locobase ID15222
RailroadLassen Lumber & Box
Number in Class1
Road Numbers25
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase9'
Engine Wheelbase24.50'
Ratio of driving wheelbase to overall engine wheebase 0.37
Overall Wheelbase (engine & tender)48.42'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers80000 lbs
Engine Weight101000 lbs
Tender Light Weight89000 lbs
Total Engine and Tender Weight190000 lbs
Tender Water Capacity5000 gals
Tender Fuel Capacity (oil/coal)1800 gals
Minimum weight of rail (calculated)44 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter46"
Boiler Pressure180 psi
Cylinders (dia x stroke)16" x 24"
Tractive Effort20435 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.91
Heating Ability
Firebox Area83 sq. ft
Grate Area16.20 sq. ft
Evaporative Heating Surface1529 sq. ft
Superheating Surface
Combined Heating Surface1529 sq. ft
Evaporative Heating Surface/Cylinder Volume273.77
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2916
Same as above plus superheater percentage2916
Same as above but substitute firebox area for grate area14940
Power L14803
Power MT397.08

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