United States Railroad Administration 2-10-2 "Santa Fe" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class Heavy (Locobase 90)

Data from tables in 1930 Locomotive Cyclopedia and from American Locomotive Company, Standardized Locomotives, US Railroad Administration (Alco Pamphlet 10049, 1918), pp. 22-23, reprinted by (Ocean, NJ: Specialty Press , 1973) and DeGolyer, Vol 58, pp. 147+.

See also "Standard Equipment Specialties," Railway Mechanical Engineer, Vol 93, No 3 (March 1919), pp. 137-138 for a list of all the "special equipment" by manufacturers--everything from air brakes to lubricators to rolled steel wheels--and the USRA designs on which they appeared.

The more widely emulated of the two USRA "Santa Fe" designs with 175 locomotives delivered to six railroads. Alco's Brooks works delivered 135 engines, 95 of them to the Pennsy. Baldwin built 40, including another 30 for the Pennsy as well as 5 for the Colorado & Southern. War's penchant for creating strange bedfellows is evident in the PRR's acceptance of non-Belpaire boilers from Alco. Firebox heating surface area included 120 sq ft (11.15 sq m) in the combustion chamber and 36 sq ft (3.35 sq m) in arch tubes. Piston valves measured 14" (356 mm) in diameter.

The Frisco liked the engines, according to Eugene Huddleston (Trains, March 1991) while the Pennsy found that when assigned to trains in accordance with their tractive power, these engines "handled their tonnage in a satisfactory manner."

The basic design performed adequately, says Huddleston, but the 2-10-2 arrangement had too long a wheelbase on a built-up (as opposed to integrally cast) frame and too little scope for proper counterbalancing. As a result, maintenance costs climbed as frames worked themselves out of true by flexing and the pounding induced by the long main and side rods. Nevertheless, most other 2-10-2s built after WW I used the same piston, boiler pressure, and driver diameter dimensions and had similar tractive efforts. Later private designs had more boiler area, a greater percentage of which was superheated.


Class Light (Locobase 89)

Data from tables in 1930 Locomotive Cyclopedia, "Two More Standard Locomotives," Railway Mechanical Engineer, Vol 93, No 1 (January 1919), pp. 25-30, and from American Locomotive Company, Standardized Locomotives, US Railroad Administration (Alco Pamphlet 10049, 1918), pp. 20-21, reprinted by (Ocean, NJ: Specialty Press , 1973) and DeGolyer, Vol 58, pp. 134+.

See also "Standard Equipment Specialties," Railway Mechanical Engineer, Vol 93, No 3 (March 1919), pp. 137-138 for a list of all the "special equipment" by manufacturers--everything from air brakes to lubricators to rolled steel wheels--and the USRA designs on which they appeared.

One of two basic "Santa Fe" designs standardized near the end of World War I, this design shared a common firebox design with the USRA's 2-6-6-2 (Locobase 14240) as well as an identical tube count. Shorter tubes accounted for a smaller heating surface area as did a shorter combustion chamber that nevertheless contributed 110 sq ft (10.2 sq m) to the firebox heating surface as did 34 sq ft (3.15 sq m) in arch tubes.

94 engines went to six railroads. Alco's Brooks works produced 75 of these, including 50 for the Southern. Baldwin added 19.

The heavy design was more widely produced than this light version, whose small drivers frustrated efforts at counterbalancing masses for smooth riding and whose light weight limited adhesion. See Southern Railway's Ss-1

Specifications by Steve Llanso of Sweat House Media
ClassHeavyLight
Locobase ID90 89
RailroadUnited States Railroad Administration (USRA)United States Railroad Administration (USRA)
CountryUSAUSA
Whyte2-10-22-10-2
Number in Class
Road Numbers10,00010,000
GaugeStdStd
Number Built
BuilderSeveralSeveral
Year19181918
Valve GearSouthernSouthern
Locomotive Length and Weight
Driver Wheelbase (ft)22.3021
Engine Wheelbase (ft)42.2040.30
Ratio of driving wheelbase to overall engine wheebase 0.53 0.52
Overall Wheelbase (engine & tender) (ft)82.8775.97
Axle Loading (Maximum Weight per Axle) (lbs)60,000
Weight on Drivers (lbs)293,000274,000
Engine Weight (lbs)380,000352,000
Tender Loaded Weight (lbs)206,100188,300
Total Engine and Tender Weight (lbs)586,100540,300
Tender Water Capacity (gals)12,00010,000
Tender Fuel Capacity (oil/coal) (gals/tons)1616
Minimum weight of rail (calculated) (lb/yd)9891
Geometry Relating to Tractive Effort
Driver Diameter (in)6357
Boiler Pressure (psi)190200
High Pressure Cylinders (dia x stroke) (in)30" x 32"27" x 32"
Tractive Effort (lbs)73,82969,575
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.97 3.94
Heating Ability
Firebox Area (sq ft)429373
Grate Area (sq ft)83.2076.30
Evaporative Heating Surface (sq ft)51564666
Superheating Surface (sq ft)12301085
Combined Heating Surface (sq ft)63865751
Evaporative Heating Surface/Cylinder Volume196.94220.03
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15,80815,260
Same as above plus superheater percentage18,81218,159
Same as above but substitute firebox area for grate area96,99788,774
Power L113,99914,601
Power MT526.66587.40


If you have any railroad data such as diagram books, rail station plans or anything else that you would be willing to share, please contact us.