Atchison, Topeka & Santa Fe 2-8-10-2 Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class ConsolDecapod? (Locobase 16142)

Data from AT&SF diagram drafted on 15 December 1930 and reproduced in E D Worley, Iron Horses of the Santa Fe (Dallas: Southwest Railroad Historical Society, 1976). p. 377.

Worley comments that this idea seems to have represented a continuing interest in Mallets that now was based on their successful 2-10-4 "Madame Queen" (Locobase 457). The enormous grate was 22 feet (6.71 m) long, just six inches shorter than the boiler tubes; its coal consumption was calculated at 142 lb/sq ft (693.3 kg/sq m) . Although the diagram doesn't explicitly say so, all four cylinders must have taken live steam because the HP/LP volume ratio would otherwise have sunk to an improbable 1.23.

NB: Superheater area and tube counts are an estimate. As the diagram shows no figures for tube counts or superheating area, Locobase feels free to make a SWAG based on the Madame Queen.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassConsolDecapod?
Locobase ID16142
RailroadAtchison, Topeka & Santa Fe (ATSF)
CountryUSA
Whyte2-8-10-2
Number in Class1
Road NumbersProposed
GaugeStd
Number Built
BuilderSanta Fe
Year1930
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)42.50 / 12.95
Engine Wheelbase (ft / m)73.75 / 22.48
Ratio of driving wheelbase to overall engine wheelbase 0.58
Overall Wheelbase (engine & tender) (ft / m)127.79 / 38.95
Axle Loading (Maximum Weight per Axle) (lbs / kg)70,000 / 31,752
Weight on Drivers (lbs / kg)630,000 / 285,764
Engine Weight (lbs / kg)730,000 / 331,123
Tender Loaded Weight (lbs / kg)410,000 / 185,973
Total Engine and Tender Weight (lbs / kg)1,140,000 / 517,096
Tender Water Capacity (gals / ML)22,000 / 83.33
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)30 / 27
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)69 / 1753
Boiler Pressure (psi / kPa)275 / 1900
High Pressure Cylinders (dia x stroke) (in / mm)27" x 34" / 686x864
Low Pressure Cylinders (dia x stroke) (in / mm)30" x 34" / 762x864
Tractive Effort (lbs / kg)187,630 / 85107.64
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.36
Heating Ability
Tubes (number - dia) (in / mm)42 - 2.25" / 57
Flues (number - dia) (in / mm)340 - 3.5" / 89
Flue/Tube length (ft / m)22.50 / 6.86
Firebox Area (sq ft / m2)788 / 73.21
Grate Area (sq ft / m2)175 / 16.26
Evaporative Heating Surface (sq ft / m2)8348 / 775.84
Superheating Surface (sq ft / m2)4000 / 371.75
Combined Heating Surface (sq ft / m2)12,348 / 1147.59
Evaporative Heating Surface/Cylinder Volume370.47
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation48,125
Same as above plus superheater percentage63,525
Same as above but substitute firebox area for grate area286,044
Power L130,330
Power MT

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