A S Johnson Lumber Company 2-6-2 "Prairie" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 9 (Locobase 11728)

Data from Negative 8871, Southern Methodist University, Central University Libraries, DeGolyer Library collection of digitized Baldwin images, retrieved 26 October 2010 from [] . See also DeGolyer Baldwin Specifications, Vol 71, pp. 269. Works number was 56767 in July 1923.

One of the smaller logging Prairies to run on the standard gauge. This oil-burner's mid-20s building date shows that certain applications--such as logging--resisted motor trucks more easily than others. It was specified to be easily convertible to burning coal fuel.

At some later date, ASJ sold the 9 to Mansfield Hardwood Lumber Company of Winnifield, La.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID11,728
RailroadA S Johnson Lumber Company
Number in Class1
Road Numbers9
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)8 / 2.44
Engine Wheelbase (ft / m)22 / 6.71
Ratio of driving wheelbase to overall engine wheebase 0.36
Overall Wheelbase (engine & tender) (ft / m)46.23 / 14.09
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)58,220 / 26,408
Engine Weight (lbs / kg)79,360 / 35,997
Tender Loaded Weight (lbs / kg)69,640 / 31,588
Total Engine and Tender Weight (lbs / kg)149,000 / 67,585
Tender Water Capacity (gals / ML)3000 / 11.36
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)1500 / 5.70
Minimum weight of rail (calculated) (lb/yd / kg/m)32 / 16
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 1067
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)13" x 22" / 330x559
Tractive Effort (lbs / kg)13,544 / 6143.46
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.30
Heating Ability
Firebox Area (sq ft / m2)74 / 6.88
Grate Area (sq ft / m2)13.30 / 1.24
Evaporative Heating Surface (sq ft / m2)767 / 71.28
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)767 / 71.28
Evaporative Heating Surface/Cylinder Volume226.94
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2394
Same as above plus superheater percentage2394
Same as above but substitute firebox area for grate area13,320
Power L14239
Power MT481.56

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