USRA 2-10-2 "Santa Fe" Type Locomotives

Class Details by Steve Llanso

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
ClassHeavyLight
Locobase ID90 89
RailroadUSRAUSRA
Whyte2-10-22-10-2
Road Numbers1000010000
GaugeStdStd
BuilderSeveralSeveral
Year19181918
Valve GearSouthernSouthern
Locomotive Length and Weight
Driver Wheelbase22.30'21'
Engine Wheelbase42.20'40.30'
Ratio of driving wheelbase to overall engine wheebase 0.53 0.52
Overall Wheelbase (engine & tender)82.87'75.97'
Axle Loading (Maximum Weight per Axle)60000 lbs
Weight on Drivers293000 lbs274000 lbs
Engine Weight380000 lbs352000 lbs
Tender Light Weight206100 lbs188300 lbs
Total Engine and Tender Weight586100 lbs540300 lbs
Tender Water Capacity12000 gals10000 gals
Tender Fuel Capacity (oil/coal)16 tons16 tons
Minimum weight of rail (calculated) on which locomotive could run98 lb/yard91 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter63"57"
Boiler Pressure190 psi200 psi
Cylinders (dia x stroke)30" x 32"27" x 32"
Tractive Effort73829 lbs69575 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.97 3.94
Heating Ability
Firebox Area429 sq. ft373 sq. ft
Grate Area83.20 sq. ft76.30 sq. ft
Evaporative Heating Surface5156 sq. ft4666 sq. ft
Superheating Surface1230 sq. ft1085 sq. ft
Combined Heating Surface6386 sq. ft5751 sq. ft
Evaporative Heating Surface/Cylinder Volume196.94220.03
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1580815260
Same as above plus superheater percentage1881218159
Same as above but substitute firebox area for grate area9699788774
Power L11399914601
Power MT526.66587.40

Credits

Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.