Monroe & Southwestern 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 14049)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 45, p. 44. See also the Tap Line summaries at and Moody's Manual of Investments, American and Foreign, Part II - Eighth Year (New York: Moody's Investors Service, 1917), p. 2013. Works number was 40942 in November 1913.

Grayling Lumber Company's 1908 Michigan incorporation represented the consolidation of the Standard Tie Company and Desha Land & Timber. The new company owned over 95,000 acres of Arkansas land in Desha County, Arkansas and Union and Ouachita Parishes in Louisiana. According to Moody's, the company's assets included a Monroe, La saw mill, planing mills, dry kilns, with a capacity of 150,000 feet (double shift) per day. The Arkansas City mill had a capacity of 75,000 feet (single shift) per day.

Altogether, the M & SW had about 10 miles of 40 lb/yard (20 kg/metre) rail and featured grades as high as 6%.

Specifications by Steve Llanso of Sweat House Media
Locobase ID14049
RailroadMonroe & Southwestern
Number in Class1
Road Numbers4
Number Built1
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase 9.17'
Engine Wheelbase23.75'
Ratio of driving wheelbase to overall engine wheebase 0.39
Overall Wheelbase (engine & tender)45.46'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers65000 lbs
Engine Weight90000 lbs
Tender Light Weight60000 lbs
Total Engine and Tender Weight150000 lbs
Tender Water Capacity3000 gals
Tender Fuel Capacity (oil/coal)6 tons
Minimum weight of rail (calculated)36 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter44"
Boiler Pressure160 psi
Cylinders (dia x stroke)15" x 24"
Tractive Effort16691 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.89
Heating Ability
Firebox Area83 sq. ft
Grate Area14.10 sq. ft
Evaporative Heating Surface1071 sq. ft
Superheating Surface
Combined Heating Surface1071 sq. ft
Evaporative Heating Surface/Cylinder Volume218.18
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2256
Same as above plus superheater percentage2256
Same as above but substitute firebox area for grate area13280
Power L13552
Power MT361.42

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