The Rio Grande also operated a standard gauge railroad and bought many powerful locomotives that included twenty-one 4-6-6-4 "Challenger" type and forty-five 2-8-8-2 "Chesapeake" type.
The Rio Grande ordered ten "Santa Fe" type locomotives for it standard gauge railroad, which the American Locomotive Company delivered in 1917. These 2-10-2s were put to work in helper service on Tennessee Pass and on Pueblo to Denver coal trains. They were designated as Class F-81 and were given road numbers 1400 through 1409. The locomotives had 63" diameter drivers, 31" x 32" cylinders, a 195 psi boiler pressure, they exerted 80,907 pounds of tractive effort and each weighed 428,500 pounds. The firebox had security brick arch and the combined heating surface was 6,698 square feet.
The ten F-81s were used in helper service in Minturn-Malta (Tennessee Pass), Colorado and on through-freight trains between Denver and Salida.
There are no surviving D&RGW 2-10-2 "Santa Fe" type locomotives.
| Class | Qty. | Road Numbers | Year Built | Builder | Notes |
|---|---|---|---|---|---|
| F-81 | 10 | 1400-1409 | 1917 | ALCO | Numbers 1408 & 1409 scrapped in 1952, number 1404 scrapped in 1954 and all of the others were scrapped in 1955. |
Described in "The Heaviest Santa Fe Type Locomotives," Railway Age Gazette, Volume 63, No 5 (3 August 1917), p. 189-192. See also "D&RG Santa Fe Type Locomotives", Railway Mechanical Engineering, Volume 91, No 8 (August 1917), pp. 431-433; and D&RGW 12 - 1937 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection. (Thanks to Chris Hohl for his 19 April 2018 email noting the original tender capacity and for his 28 March 2019 email noting increased capacity and the date of the longer tender.) Works numbers were 56620-56629 in March 1917.
Firebox had Security brick arch and Street (later Duplex) stoker. 16-inch (406 mm) piston valves supplied steam to the cylinders. The "as-delivered" tender was a stubby affair, rolling on just four axles; with it the engine and tender wheelbase came to 76 ft 9 3/4 in (23.41 m) It carried a lot of coal--21 tons (19.05 metric tons)--but water was limited to 10,000 US gallons (37,850 litres). Its loaded weight came to 196,400 lb (89.086 kg). By the 1930s, the tender carried 24 tons (21.8 metric tons).
A requirement that these engines handle 16-deg curves was met by spacing the drivers of the first, main, and last pairs (every other one, in other words) 1/4" closer together (down to 53 1/8") and the second and fourth at 53 3/8". The front drivers also rode in a Woodward floating front driving axle, which reduced rigid wheelbase to 16 feet, 6 inches (5.03 m).
When introduced, five were used in Minturn-Malta (Tennessee Pass), Colorado helper service for trains tackling the ruling 3% grade and the other five ran through-freights between Denver and Salida (ruling grade 1.42%).
The class went through few changes, although a later update reshaped the firebox heating surface area to add 96 sq ft (8.9 sq m) of thermic syphons to the 324 sq ft (80.1 sq m) of the basic furnace and combustion chamber.
Hohl, citing Donald J Heimburger, Rio Grande Steam Locomotives - Standard Gauge (Heimburger House Publishing Company, 1996), pp. 57, 59, reports that beginning in 1947, the class began turning in their Vanderbilt cylindrical tenders in favor of rectangular tenders of similar capacity. Adhesion weight climbed to 353,700 lb (160,436 kg) and engine weight increased to 438,400 lb (198,855 kg). 1406 now used security circulators instead of syphons.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | F-81 |
| Locobase ID | 429 |
| Railroad | Denver & Rio Grande Western (D&RGW) |
| Country | USA |
| Whyte | 2-10-2 |
| Number in Class | 10 |
| Road Numbers | 1250-1259/1400-1409 |
| Gauge | Std |
| Number Built | 10 |
| Builder | Alco-Brooks |
| Year | 1917 |
| Valve Gear | Baker |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 22.50 / 6.86 |
| Engine Wheelbase (ft / m) | 41.42 / 12.62 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.54 |
| Overall Wheelbase (engine & tender) (ft / m) | 87.39 / 23.41 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 72,100 / 32,704 |
| Weight on Drivers (lbs / kg) | 337,500 / 153,088 |
| Engine Weight (lbs / kg) | 428,500 / 194,365 |
| Tender Loaded Weight (lbs / kg) | 286,480 / 129,945 |
| Total Engine and Tender Weight (lbs / kg) | 714,980 / 324,310 |
| Tender Water Capacity (gals / ML) | 16,000 / 60.61 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 23 / 21 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 113 / 56.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 63 / 1600 |
| Boiler Pressure (psi / kPa) | 195 / 1340 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 31" x 32" / 787x813 |
| Tractive Effort (lbs / kg) | 80,907 / 36698.84 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.17 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 252 - 2.25" / 57 |
| Flues (number - dia) (in / mm) | 48 - 5.5" / 140 |
| Flue/Tube length (ft / m) | 23 / 7.01 |
| Firebox Area (sq ft / m2) | 368 / 34.19 |
| Grate Area (sq ft / m2) | 88 / 8.18 |
| Evaporative Heating Surface (sq ft / m2) | 5369 / 498.79 |
| Superheating Surface (sq ft / m2) | 1329 / 123.47 |
| Combined Heating Surface (sq ft / m2) | 6698 / 622.26 |
| Evaporative Heating Surface/Cylinder Volume | 192.09 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 17,160 |
| Same as above plus superheater percentage | 20,592 |
| Same as above but substitute firebox area for grate area | 86,112 |
| Power L1 | 14,043 |
| Power MT | 458.66 |
