Mallet compound with 39-in LP cylinders. Later variant of the L-95 and basically a copy of the USRA heavy articulated. Note the good boiler proportions in which the firebox heating surface included 49 sq ft of arch tubes and 82 sq ft of combustion chamber for a total of 435 sq ft. Before long, direct heating surface expanded in one of two ways. In one, 115 sq ft of syphons replaced the arch tubes; that version is shown in the specification. In the other, firebox circulators added 76 sq ft to the surface for a total of 462 sq ft.
They saw out steam, being retired in 1947-1951.
Firebox heating surface includes the combustion chamber (170 sq ft) and thermic syphons in both the combustion chamber and in the firebox (137 sq ft) or circulators (143 sq ft), boiler fitted with feedwater heater, valve motion limited cutoff.
Ten engines that were simple-expansion improvements on the earlier Mallet compounds. Rated at 3,300 tons on the east side of the Continental Divide (maximum grade 1.42%) and 1,400 tons on the west slope (max grade 3%). A later class of 10 (3610-3619) from Alco was designated L-132.
These Mallets preceded the 2-10-2s described in a Railway Age Gazette article of 3 August 1917. Used in Minturn-Malta (Tennessee Pass), Colorado helper service. Rio Grande's calculation of compound tractive effort yielded 96,000 lb.
The specifications refer to the later boiler (new in 1941) whose firebox heating surface included 114 sq ft in the combustion chamber and 88 sq ft in thermic syphons in both the firebox and the combustion chamber.
| Specifications | |||
|---|---|---|---|
| Class | L-107 | L-131 | L-95 |
| Locobase ID | 315 | 316 | 435 |
| Railroad | Denver & Rio Grande Western (D&RGW) | Denver & Rio Grande Western (D&RGW) | Denver & Rio Grande Western (D&RGW) |
| Whyte | 2-8-8-2 | 2-8-8-2 | 2-8-8-2 |
| Road Numbers | 3500-3509 | 3600-3609 | 3400-3415 |
| Gauge | Std | Std | Std |
| Builder | Alco | Alco | Alco |
| Year | 1923 | 1927 | 1913 |
| Valve Gear | Walschaert | Walschaert | |
| Locomotive Length and Weight | |||
| Driver Wheelbase | 42.32' | 16.75' | 15' |
| Engine Wheelbase | 58.01' | 62.83' | 55.67' |
| Ratio of driving wheelbase to overall engine wheebase | 0.73 | 0.27 | 0.27 |
| Overall Wheelbase (engine & tender) | 94.49' | 89.54' | |
| Axle Loading (Maximum Weight per Axle) | 61401 lbs | 71000 lbs | 54125 lbs |
| Weight on Drivers | 481000 lbs | 559500 lbs | 414700 lbs |
| Engine Weight | 534001 lbs | 649000 lbs | 482500 lbs |
| Tender Light Weight | 210001 lbs | 343000 lbs | 291400 lbs |
| Total Engine and Tender Weight | 744002 lbs | 992000 lbs | 773900 lbs |
| Tender Water Capacity | 12012 gals | 18000 gals | 13000 gals |
| Tender Fuel Capacity (oil/coal) | 16 tons | 30 tons | 20 tons |
| Minimum weight per yard of rail on which locomotive could run | 100.21 lb rail | 116.56 lb rail | 86.40 lb rail |
| Geometry Relating to Tractive Effort | |||
| Driver Diameter | 57" | 63" | 57" |
| Boiler Pressure | 239 psi | 240 psi | 200 psi |
| Cylinders (dia x stroke) | 25" x 32.01" | 26" x 32" (4) | 26" x 32" |
| Low Pressure Cylinders (dia x stroke) | 39.02" x 32.01" | " x " | 40" x 32" |
| Tractive Effort | 101104 lbs | 140093 lbs | 90709 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.76 | 3.99 | 4.57 |
| Heating Ability | |||
| Firebox Area | 506.98 sq. ft | 715 sq. ft | 385 sq. ft |
| Grate Area | 96.55 sq. ft | 136.50 sq. ft | 80.29 sq. ft |
| Evaporative Heating Surface | 6147 | 7265 | 4944 |
| Superheating Surface | 1582 | 2295 | 1331 |
| Combined Heating Surface | 7729 | 9560 | 6275 |
| Evaporative Heating Surface/Cylinder Volume | 338.00 | 184.73 | 251.42 |
| Computations Relating to Power Output (More Information) | |||
| Robert LeMassena's Power Computation | 23075.45 | 32760 | 16058 |
| Same as above plus superheater percentage | 27798.62 | 40624.46 | 19464.09 |
| Same as above but substitute firebox area for grate area | 145969.37 | 212794.77 | 93332.59 |
| Power L1 | 11746.21 | 20180.84 | 7694.36 |
| Power MT | 430.70 | 636.16 | 327.24 |
| This page last modified: . | [Contact] | All material © 1999-2008 SteamLocomotive.com |
