Denver & Rio Grande Western 2-6-6-2 Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class L-62 (Locobase 294)

Data from Wiener (1930); another source has the grate area as 63.4 sq ft, but a 3rd source (Bruce, 1952) agrees with Wiener and this is borne out by the D&RGW 1956 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Eight Mallet compounds for helper service in Soldier Pass and Tennessee Pass. They were delivered as saturated-steam locomotives with a total of 395 2" tubes and a firebox whose heating surface included 40 sq ft of combustion chamber. Total EHS was 4,114 sq ft. As shown in the specs, however, they were later superheated. Unlike most such conversions, this class retained virtually all of the heating surface area of the saturated boiler.

Later renumbered 3300-3307. Retired in 1947-1952.

Class L-76 (Locobase 1466)

These two Mallet compounds were bought from the Norfolk & Western by the Denver & Rio Grande Western in 1947 to beef up helper service Retired in 1952 and 1950, respectively.

Data from 1952 D & RGW locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Specifications by Steve Llanso of Sweat House Media
Locobase ID294 1466
RailroadDenver & Rio Grande Western (D&RGW)Denver & Rio Grande Western (D&RGW)
Number in Class82
Road Numbers3300-33073350-3351
Number Built8
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft)30.3310
Engine Wheelbase (ft)46.3348.83
Ratio of driving wheelbase to overall engine wheebase 0.65 0.20
Overall Wheelbase (engine & tender) (ft)74.5090.77
Axle Loading (Maximum Weight per Axle) (lbs)51,60062,600
Weight on Drivers (lbs)295,500364,500
Engine Weight (lbs)640,000427,000
Tender Light Weight (lbs)159,000286,533
Total Engine and Tender Weight (lbs)799,000713,533
Tender Water Capacity (gals)800016,000
Tender Fuel Capacity (oil/coal) (gals/tons)1223
Minimum weight of rail (calculated) (lb/yd)82101
Geometry Relating to Tractive Effort
Driver Diameter (in)5757
Boiler Pressure (psi)210225
High Pressure Cylinders (dia x stroke) (in)20.5" x 32"22" x 32"
Low Pressure Cylinders (dia x stroke) (in)33" x 32"35" x 32"
Tractive Effort (lbs)60,77474,498
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.86 4.89
Heating Ability
Firebox Area (sq ft)250391
Grate Area (sq ft)54.4072.20
Evaporative Heating Surface (sq ft)34494629
Superheating Surface (sq ft)657971
Combined Heating Surface (sq ft)41065600
Evaporative Heating Surface/Cylinder Volume282.14328.79
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,42416,245
Same as above plus superheater percentage13,25219,007
Same as above but substitute firebox area for grate area60,900102,931
Power L166839192
Power MT299.16333.58


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