Denver & Rio Grande 2-4-0 "Porter" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class Montezuma (Locobase 1448)

Data from and from Data from Baldwin Locomotive Works Specification for Engines, as digitized by the DeGolyer Library of Southern Methodist University, Volume 5, p. 217. Works number was 2459 in May 1871.

Early narrow-gauge wood-burner in Colorado. The Baldwin specs add:"Steam Jets in front of Cylinder to scare cattle!" (Exclamation point in the original.) The passenger engines pulled as many as six cars. The latter were supplied by the well-known car builder Jackson & Sharp of Wilmington, Del, then the only such manufacturer for narrow-gauge railroads in the country. (The order was shipped to Denver in July 1871 and arrived 18 days later on 2 August.)

Paul T. Warner, Baldwin historian, wrote in a history of the works reproduced in Westing (1966), that this design (works number 2459) was "found to be too small and to be unsteady on the track, owing to its comparatively short wheelbase. It [the type] was therefore abandoned, and the ordinary American pattern, eight-wheeled, four-coupled, substituted." (The layout would endure as suitable for a small sugar-plantation locomotive.)

Ran until 1887.

Specifications by Steve Llanso of Sweat House Media
Locobase ID1448
RailroadDenver & Rio Grande (D&RGW)
Number in Class4
Road Numbers1
Number Built4
BuilderM. Baird & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)
Engine Wheelbase (ft)
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender) (ft)
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)20,500
Engine Weight (lbs)25,300
Tender Loaded Weight (lbs)
Total Engine and Tender Weight (lbs)
Tender Water Capacity (gals)500
Tender Fuel Capacity (oil/coal) (gals/tons) 1.50
Minimum weight of rail (calculated) (lb/yd)17
Geometry Relating to Tractive Effort
Driver Diameter (in)40
Boiler Pressure (psi)130
High Pressure Cylinders (dia x stroke) (in)9" x 16"
Tractive Effort (lbs)3580
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.73
Heating Ability
Firebox Area (sq ft)
Grate Area (sq ft) 6.25
Evaporative Heating Surface (sq ft)
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation813
Same as above plus superheater percentage813
Same as above but substitute firebox area for grate area
Power L1
Power MT


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