Saint Louis & North Arkansas 2-6-0 "Mogul" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class M-26 (Locobase 6640)

Data from 1904 M & NA locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 25, p. 122. Works numbers were 21456 and 21462 in January 1903.

The M&NA went to Baldwin to build two more locomotives of the same power and size as the Ten-wheelers they'd received from Cooke. But, for some reason, these were Moguls. They looked like 4-6-0s with the rear truck axle removed..

The StL&NA was reorganized as the Missouri & Northern Arkansas in 1904, but these engines kept the same numbers until they were retired in 1929 and scrapped in 1934-1935.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID6640
RailroadSaint Louis & North Arkansas
Number in Class2
Road Numbers6-7
Number Built2
BuilderBurnham, Williams & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)12 / 3.66
Engine Wheelbase (ft / m)21 / 6.40
Ratio of driving wheelbase to overall engine wheebase 0.57
Overall Wheelbase (engine & tender) (ft / m)49.83 / 15.19
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)115,000 / 52,163
Engine Weight (lbs / kg)135,000 / 61,235
Tender Loaded Weight (lbs / kg)120,000 / 54,431
Total Engine and Tender Weight (lbs / kg)255,000 / 115,666
Tender Water Capacity (gals / ML)6000 / 22.73
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)10 / 9.10
Minimum weight of rail (calculated) (lb/yd / kg/m)64 / 32
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 1422
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)19" x 26" / 483x660
Tractive Effort (lbs / kg)25,644 / 11631.94
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.48
Heating Ability
Firebox Area (sq ft / m2)163.60 / 15.20
Grate Area (sq ft / m2)30.60 / 2.84
Evaporative Heating Surface (sq ft / m2)1963 / 182.37
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1963 / 182.37
Evaporative Heating Surface/Cylinder Volume230.07
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5508
Same as above plus superheater percentage5508
Same as above but substitute firebox area for grate area29,448
Power L15476
Power MT314.93

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Wes Barris