Frost-Johnson Lumber Company 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 103 (Locobase 13718)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 36, p. 143. (Thanks to Chris Hohl for his 8 February 2015 email estimating the engine's wood capacity.) Works number was 36139 in February 1911.

Although deploying one more axle than did the 2-6-0 ordered at the same time for F-J railroad Louisiana & Pine Bluff (Locobase 11097), this was a lighter, smaller engine. It must have traveled to the end of track on all the little logging spurs used to harvest the vast stands of long-leaf pine in the region.

Class 104 (Locobase 14294)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 52, p. 335. Works number was 41926 in February 1915.

Each logging Prairie delivered to the FJLC was a bit bigger than the one that preceded it, so the 104 was larger than the 103 (Locobase 13718) and smaller than the 105 (Locobase 14944). All were wood-burners. The 104's tender was rated to carry 4 cords of wood. Locobase hasn't determined for which rail line the 104 operated.

Class 105 (Locobase 14944)

Data from DeGolyer Library, Volume 65, pp. 123+. (Thanks to Chris Hohl for the 105's fuel capacity.) Works number was 54232 in January 1921.

This wood-burning logging Prairie followed the 1915 Baldwin shown in Locobase 14294 into service. It had a boiler with a few more tubes of greater length, but the same power dimensions and grate area and like most such Baldwins, carried 3 cords of wood in the tender. F-J didn't have much wiggle room for size given the 35 lb/yard (17.5 kg) rail and the 19-degree curves (radii of 200 feet/61 metres).

Specifications by Steve Llanso of Sweat House Media
Locobase ID13718 14294 14944
RailroadFrost-Johnson Lumber CompanyFrost-Johnson Lumber CompanyFrost-Johnson Lumber Company
Number in Class111
Road Numbers103104105
Number Built111
Valve GearStephensonStephensonWalschaert
Locomotive Length and Weight
Driver Wheelbase 9.17'10'10'
Engine Wheelbase23.75'25.25'25.58'
Ratio of driving wheelbase to overall engine wheebase 0.39 0.40 0.39
Overall Wheelbase (engine & tender)44.87'46.52'25.58'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers61000 lbs77000 lbs80000 lbs
Engine Weight83000 lbs102000 lbs107800 lbs
Tender Light Weight70000 lbs70000 lbs60000 lbs
Total Engine and Tender Weight153000 lbs172000 lbs167800 lbs
Tender Water Capacity3500 gals3500 gals3000 gals
Tender Fuel Capacity (oil/coal)
Minimum weight of rail (calculated)34 lb/yard43 lb/yard44 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter46"47"44"
Boiler Pressure180 psi180 psi160 psi
Cylinders (dia x stroke)15" x 20"16" x 24"16" x 24"
Tractive Effort14967 lbs20001 lbs18991 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.08 3.85 4.21
Heating Ability
Firebox Area82.20 sq. ft92 sq. ft94 sq. ft
Grate Area14.10 sq. ft14 sq. ft14 sq. ft
Evaporative Heating Surface991 sq. ft1508 sq. ft1609 sq. ft
Superheating Surface
Combined Heating Surface991 sq. ft1508 sq. ft1609 sq. ft
Evaporative Heating Surface/Cylinder Volume242.26270.01288.09
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation253825202240
Same as above plus superheater percentage253825202240
Same as above but substitute firebox area for grate area147961656015040
Power L1473049684368
Power MT512.85426.72361.12

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