Great Western 2-10-0 "Decapod" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class 90 (Locobase 11372)

Data from 1944 KO&G Locomotive Diagrams book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 74, pp. 391+. (Thanks to Chris Hohl for confirming tender capacity. And many thanks to Chris Hohl for his 31 March 2015 email providing updated information from the Strasburg's Vice President Motive Power, Equipment & Shops Kelly Anderson and to Anderson for permitting Locobase to attribute the information.) Works number 57812 in June 1924.

See Locobases 1396-1397 for a description of this stock Baldwin light decapod bought by several railroads in the 1920s. Like the others, this locomotive used 12" (305 mm) piston valves.

The 90 was one of two locomotives built to this specification (the other being Osage Railway's #10 - Locobase 6781) that did not head south from Baldwin. Instead, the Colorado-based Great Western Sugar Company used her to haul 40-50 car trains of sugar beets to factories in Longmont, Loveland, Windsor, Johnstown, and Eaton.

After more than 40 years of service, the GWR sold the 90 to the 4.5-mile (7.25 km) long Strasburg Railroad in 1967 for a reported $50,000. Well after 2010, the 90 remained in regular service on this Pennsylvania museum railroad.

Chris Hohl's 2015 conversation with Kelly Anderson revealed that the Strasburg had increased both the tender's coal and water capacities. Anderson said that the open space beneath the coal bunker had been closed in, which allowed a 1,000 US gallon (3,785 litre) increase in water capacity. In addition, taller coal boards on the sides and back of the tender replaced the originals, which increased the coal capacity to 15 tons (13,608 kg).

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID11372
RailroadGreat Western
Number in Class1
Road Numbers90
Number Built1
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)20 / 6.10
Engine Wheelbase (ft / m)28.67 / 8.74
Ratio of driving wheelbase to overall engine wheebase 0.70
Overall Wheelbase (engine & tender) (ft / m)64 / 19.51
Axle Loading (Maximum Weight per Axle) (lbs / kg)38,000 / 17,237
Weight on Drivers (lbs / kg)190,000 / 86,183
Engine Weight (lbs / kg)212,000 / 96,162
Tender Loaded Weight (lbs / kg)161,000 / 73,028
Total Engine and Tender Weight (lbs / kg)373,000 / 169,190
Tender Water Capacity (gals / ML)8000
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)12
Minimum weight of rail (calculated) (lb/yd / kg/m)63 / 31.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 1422
Boiler Pressure (psi / kPa)190 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)24" x 28" / 610x711
Tractive Effort (lbs / kg)46,512 / 21097.51
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.08
Heating Ability
Firebox Area (sq ft / m2)197 / 18.31
Grate Area (sq ft / m2)54.30 / 5.05
Evaporative Heating Surface (sq ft / m2)2343 / 217.75
Superheating Surface (sq ft / m2)553 / 51.39
Combined Heating Surface (sq ft / m2)2896 / 269.14
Evaporative Heating Surface/Cylinder Volume159.81
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,317
Same as above plus superheater percentage12,277
Same as above but substitute firebox area for grate area44,542
Power L110,046
Power MT582.83

  • 90 (photographer unknown, 11/1957 Eaton, CO photo courtesy Carl Weber)
  • 90 (photographer unknown, ~1925 Loveland, CO photo courtesy Carl Weber)
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Wes Barris