Denver & Rio Grande / Rio Grande Western 2-6-0 "Mogul" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 203 (Locobase 12249)

Data from Railway Age and Northwestern Reporter, Vol 24 (24 December 1897), p. 1039. See also Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 21, p. 146; see the extra page of details for various components and materials. Works numbers were 15561-15564 in November 1897.

At the same time Baldwin delivered the quartet of Ten-wheelers down in Locobase 12248 to the RGW, the company also produced this foursome of powerful Moguls. They were among the few US classes in this wheel arrangement to use the larger-diameter 2 1/4" tubes in boilers that ranked among the top in the ratio of heating surface area to cylinder volume.

Class 35 (Locobase 1449)

Data from Westing 1966; . See also Baldwin Locomotive Works Specification for Engines, as digitized by the DeGolyer Library of Southern Methodist University, Volume 6, pp. 44-45, 156, 223; Volume 7 p. 141. Works numbers were 2476-2479 in June 1871; 2568 in September; 2727-2728 in March 1872; 2897 in August, 3021 in November, and 3165 in March 1873.

Early narrow-gauge Moguls in Colorado. Fitted with Westinghouse air brakes in 1872. All of the class had names: Show-wa-no 3, Tabi-Wachi 2, Ouray 5, Arkansas 8, Huerfano 9, San Carlos 10, Cuchuras 11, and Las Animas 12. The Las Animas had a larger tender that carried 1,000 gallons (3,785 litres) of water.

Ran until 1883.

Class 40 (Locobase 1450)

Data from and DeGolyer, Volume 7, p. 215. Works numbers for the first two were 3806 and 3809 in December 1875.

Second class of narrow-gauge Moguls with cylinders just 1 inch bigger in Colorado. First with eight-wheel, two-truck tenders. Their names were Santa Clara, Chicosa, Raton. Ran until 1889, when the first was dismantled.

A fourth engine built to the same specs first operated on the Centennial Narrow Gauge as the Delaware during the 1876 Philadelphia Exposition (Locobase 9680). The fair ended in 1877 and she was sold to the D&RG as their 19 and named Monte Christo

Class 805 / G-20 (Locobase 11704)

Data from Baldwin Locomotive Works Specification for Engines, 1890, as digitized by the DeGolyer Library of Southern Methodist University Vol 16, p. 110.

Works numbers were


October 11292-11293, 11296-11297, 11300, 11302, 11312

December 11446-11447, 11450, 11463, 11485, 11487, 11494-11495


January 11560-11561

February 11579, 11623-11624

May 11881, 11886

The mountainous profile of the D & RG dictated the small drivers on these Moguls. The class clambered up and down the lines hauling local freight for 25 years and more. 805-807 were renumbered 827-829 in 1908.

Most were scrapped in the mid-19teens, but 821 was rebuilt as a 2-6-0T tank engine in 1917 and the 578 (renumbered from 828 in 1928) was similarly made over in 1928. 814 and 823 were sold to the Denver & Intermountain Railway in July 1917 and 809 was sold in August 1917 to Elk Creek Coal Company.

819, 821-822, 826 were renumbered in 1924 to 579, 575, 577, 576 respectively.

Specifications by Steve Llanso of Sweat House Media
Class2033540805 / G-20
Locobase ID12,249 1449 1450 11,704
RailroadRio Grande Western (D & RGW)Denver & Rio Grande (D&RGW)Denver & Rio Grande (D&RGW)Denver & Rio Grande (D&RGW)
Number in Class48422
Road Numbers200-2032-3, 5, 8-1213-15, 19805-826
Number Built48422
BuilderBurnham, Williams & CoM. Baird & CoBurnham, Parry, Williams & CoBurnham, Parry, Williams & Co
Valve GearStephensonStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)14.1711.6712.50
Engine Wheelbase (ft)22.5017719.75
Ratio of driving wheelbase to overall engine wheebase 0.63 0.07 0.63
Overall Wheelbase (engine & tender) (ft)52.30
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)85,000
Engine Weight (lbs)140,60035,00040,000100,000
Tender Loaded Weight (lbs)84,000
Total Engine and Tender Weight (lbs)224,600
Tender Water Capacity (gals)500075012003000
Tender Fuel Capacity (oil/coal) (gals/tons)
Minimum weight of rail (calculated) (lb/yd)47
Geometry Relating to Tractive Effort
Driver Diameter (in)61363646
Boiler Pressure (psi)200130130140
High Pressure Cylinders (dia x stroke) (in)20" x 26"11" x 16"12" x 16"18" x 24"
Tractive Effort (lbs)28,9845942707220,116
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.23
Heating Ability
Firebox Area (sq ft)14560125.65
Grate Area (sq ft)28.50 7.90 8.4020.40
Evaporative Heating Surface (sq ft)20644511629
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)20644511629
Evaporative Heating Surface/Cylinder Volume218.32215.34230.46
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5700102710922856
Same as above plus superheater percentage5700102710922856
Same as above but substitute firebox area for grate area29,000780017,591
Power L1599927973428
Power MT266.73


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