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.
Data from 1952 D & RGW locomotive diagram book supplied in May 2005 by Allen Stanley from his extensive collection.
| Specifications | ||
|---|---|---|
| Class | L-62 | L-76 |
| Locobase ID | 294 | 1466 |
| Railroad | Denver & Rio Grande Western (D&RGW) | Denver & Rio Grande Western (D&RGW) |
| Whyte | 2-6-6-2 | 2-6-6-2 |
| Road Numbers | 3300-3307 | 3350-3351 |
| Gauge | Std | Std |
| Builder | Alco | Alco-Schenectady |
| Year | 1910 | 1916 |
| Valve Gear | Walschaert | Walschaert |
| Locomotive Length and Weight | ||
| Driver Wheelbase | 30.33' | 10' |
| Engine Wheelbase | 46.33' | 48.83' |
| Ratio of driving wheelbase to overall engine wheebase | 0.65 | 0.20 |
| Overall Wheelbase (engine & tender) | 74.50' | 90.77' |
| Axle Loading (Maximum Weight per Axle) | 51600 lbs | 62600 lbs |
| Weight on Drivers | 295500 lbs | 364500 lbs |
| Engine Weight | 640000 lbs | 427000 lbs |
| Tender Light Weight | 159000 lbs | 286533 lbs |
| Total Engine and Tender Weight | 799000 lbs | 713533 lbs |
| Tender Water Capacity | 8000 gals | 16000 gals |
| Tender Fuel Capacity (oil/coal) | 12 tons | 23 tons |
| Minimum weight per yard of rail on which locomotive could run | 82 lb rail | 101.25 lb rail |
| Geometry Relating to Tractive Effort | ||
| Driver Diameter | 57" | 57" |
| Boiler Pressure | 210 psi | 225 psi |
| Cylinders (dia x stroke) | 20.5" x 32" | 22" x 32" |
| Low Pressure Cylinders (dia x stroke) | 33" x 32" | 35" x 32" |
| Tractive Effort | 60774 lbs | 74498 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.86 | 4.89 |
| Heating Ability | ||
| Firebox Area | 250 sq. ft | 391 sq. ft |
| Grate Area | 54.40 sq. ft | 72.20 sq. ft |
| Evaporative Heating Surface | 3449 | 4629 |
| Superheating Surface | 657 | 971 |
| Combined Heating Surface | 4106 | 5600 |
| Evaporative Heating Surface/Cylinder Volume | 282.14 | 328.79 |
| Computations Relating to Power Output (More Information) | ||
| Robert LeMassena's Power Computation | 11424 | 16245 |
| Same as above plus superheater percentage | 13252 | 19061.77 |
| Same as above but substitute firebox area for grate area | 60900 | 103229.24 |
| Power L1 | 6683 | 9191.53 |
| Power MT | 299.16 | 333.56 |
| This page last modified: . | [Contact] | All material © 1999-2010 SteamLocomotive.com |