Bonhomie Southwestern 2-6-2 "Prairie" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 14308)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 52, p. 350. See also Mississippi Rails website's description at . Works number was 43121 in March 1916.

This logging road was chartered in August 1910 by Mississippi's Tatum Lumber Company. Anchored on the northern end at Hattiesburg, the line angled south to Okahola, then west to Columbia for a total of 35 miles (56.4 km). Mississippi Rails reports two conditions of note in the charter: Finish the road in five years and the road was "not required to operate freight and passenger trains on Sundays, except in emergencies, in the 'promotion of the Christian religion.'".

The Baldwin spec stated that the firebox of this wood-burning logging Prairie was to be placed on top of the frames (perhaps for clearance reasons?). Rail weights on the road were given as 56 lb/yard (28 kg/metre), maximum grades rose at 3%, and the line curved at a relatively gentle 14 degrees (radius of 410 feet/125 metres).

Specifications by Steve Llanso of Sweat House Media
Locobase ID14308
RailroadBonhomie Southwestern
Number in Class1
Road Numbers4
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase10.25'
Engine Wheelbase26.83'
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender)50.58'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers92000 lbs
Engine Weight121000 lbs
Tender Light Weight80000 lbs
Total Engine and Tender Weight201000 lbs
Tender Water Capacity4000 gals
Tender Fuel Capacity (oil/coal)
Minimum weight of rail (calculated)51 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter44"
Boiler Pressure170 psi
Cylinders (dia x stroke)17" x 24"
Tractive Effort22778 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.04
Heating Ability
Firebox Area101 sq. ft
Grate Area18.90 sq. ft
Evaporative Heating Surface1637 sq. ft
Superheating Surface
Combined Heating Surface1637 sq. ft
Evaporative Heating Surface/Cylinder Volume259.64
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3213
Same as above plus superheater percentage3213
Same as above but substitute firebox area for grate area17170
Power L14235
Power MT304.45

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