Southern 2-10-2 "Santafe" Locomotives in the USA

The first ten-coupled locomotives on the Southern Railway were the fifty-five "Santa Fe" type ordered from the Baldwin Locomotive Works. This group was designated as Class Ss and given road numbers 5000 through 5054 and was delivered during 1917 and 1918. At the same time the American Locomotive Company built twenty-five of the Class Ss and delivered them in 1918 to the CNO&TP.

These locomotives proved to be to bulky for the CNO&TP Railway's tight clearances and were transferred to the Southern roster with road numbers 5055 through 5079 assigned. All of the Class Ss locomotives had 57" diameter drivers, 28" x 32" cylinders, a 190 psi boiler pressure, they exerted 71,083 pounds of tractive effort and each weighed 370,600 pounds.

While Baldwin was building the Class Ss it received direction from the USRA to build five "Santa Fe-Lights" for the Southern Railway. These locomotives were designated as Class Ss-1 and were assigned road numbers 5205, 5212, 5217, 5224 and 5234.

ALCO built another forty-five of the Class Ss-1 at the direction of the USRA and delivered them during 1918. This group of locomotives was given road numbers between 5200 through 5249 less the five numbers given to the Baldwin-built locomotives of the same class.

The class Ss-1 locomotives had 57" diameter drivers, 27" x 32" cylinders, a 200 psi boiler pressure, they exerted 69,575 pounds of tractive effort and each weighed 352,000 pounds.

There are no surviving Southern 2-10-2 "Santa Fe" type locomotives.


ClassQty.Road NumbersYear BuiltBuilderNotes
Ss-1 55205,12,17,24,341917Baldwin2
Ss-1 55200-52041918ALCO2
Ss-1 65206-52111918ALCO2
Ss-1 45213-52161918ALCO2
Ss-1 65218-52231918ALCO2
Ss-1 95225-52331918ALCO2
  1. Numbers 5000-5079 scrapped between 1938 and 1952.
  2. USRA allocated .Santa Fe.-Light locomotives. Numbers 5200-5249 scrapped between 1938 and 1942.

Class Details by Steve Llanso of Sweat House Media

Class Ss (Locobase 84)

Some data from Southern Railway diagrams hosted on (viewed September 2002). Evaporative heating surface information from locomotive diagram book provided in April 2004 from Allen Stanley's extensive Rail Data Exchange. See also DeGolyer, Vol 56, pp. 404+. Also see Frank Clodfelter, "Saluda:A piece of railroad that must be watched every minute," Trains Magazine ( November 1984), pp. 26-39, preserved on []

Fifty built by Baldwin (5000-5054) with a engine weight of 367,000 lb. Works numbers were


January 44907-44908, 44926-44927

February 45074-45076, 45113-45115

March 45272-45277, 45327-45331

April 45441-45444, 45455-45458

May 45573

July 45958, 45975, 46002-46003

August 46063, 46106-46107, 46166-46167

September 46352, 46405, 46441-46442


February 47920

March 48070, 48148

April 48268-48270, 48298-48299

May 48578, 48679-48680

June 49032

Twenty-five others built by Alco's Richmond Works for subsidiary CNO&TP, later moved to Southern with numbers 5055-5074 when the 2-10-2s proved too bulky for the railway's tight clearances.. Works numbers were 59058-59082 in 1918. These had max weight of 378,000 lb, slightly higher TE. Baldwin's specs show 14" (356 mm) piston valves, 66 sq ft (6.1 sq m) of heating surface in the combustion chamber, and 46 sq ft (4.3 sq m) in four arch tubes.

Both classes later ran at 200 psi. For later service on the Asheville Division (including the notorious Blue Ridge and Saluda grades), some of these engines were fitted with "floating" front drivers. The arrangement consisted of spherical bearings on the forward end of the side rods and Franklin lateral-motion driving boxes for the front axle.

Frank Clodfelter detailed (p. 33) other alterations designed to help crews cope with this fearsome section: "Shop forces at Asheville made several modifications to SS-class Santa Fe's assigned to Saluda. The water glass on both the engineer's and fireman's side was made longer than normal so that crews could safely measure the water level in the boiler while descending or ascending the mountain; a second air pump was installed because of the excessive use of air brakes on Saluda; some engines used as helpers or on the head end of passenger trains were equipped with cab signals and steam-heat connections; and water pipes were installed over the driving wheels so that a constant flow of water would cool the tires while descending the mountain."

Class Ss-1 (Locobase 1427)

Data from tables and diagram in 1930 Locomotive Cyclopedia and SRY 6 - 1947 List and Description of Locomotives supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Alco's Brooks Works numbers were 60010-60059.

Firebox had combustion chamber. One of the USRA's two basic "Santa Fe" designs standardized near the end of World War I. These 50 went to the Southern and used on Saluda grade service in western North Carolina. But their longer rigid wheelbase eventually limited them to Knoxville-based service.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID84 1427
RailroadSouthern (SRS)Southern (SRS)
Number in Class8045
Road Numbers5000-50795200-5249
Number Built8045
Valve GearSouthernSouthern
Locomotive Length and Weight
Driver Wheelbase (ft / m)20.59 / 6.2821 / 6.40
Engine Wheelbase (ft / m)38.67 / 11.7940.30 / 12.28
Ratio of driving wheelbase to overall engine wheebase 0.53 0.52
Overall Wheelbase (engine & tender) (ft / m)74.80 / 22.8075.97 / 23.16
Axle Loading (Maximum Weight per Axle) (lbs / kg)60,100 / 27,26160,000 / 27,216
Weight on Drivers (lbs / kg)294,400 / 133,538276,000 / 125,192
Engine Weight (lbs / kg)370,600 / 168,102352,000 / 159,665
Tender Loaded Weight (lbs / kg)176,000 / 79,832188,300 / 85,412
Total Engine and Tender Weight (lbs / kg)546,600 / 247,934540,300 / 245,077
Tender Water Capacity (gals / ML)9000 / 34.0910,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)12 / 10.9016 / 14.50
Minimum weight of rail (calculated) (lb/yd / kg/m)98 / 4992 / 46
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 144857 / 1448
Boiler Pressure (psi / kPa)190 / 13.10200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)28" x 32" / 711x81327" x 32" / 686x813
Tractive Effort (lbs / kg)71,083 / 32242.7469,575 / 31558.73
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.14 3.97
Heating Ability
Firebox Area (sq ft / m2)358.50 / 33.31373 / 34.67
Grate Area (sq ft / m2)88 / 8.1876.30 / 7.09
Evaporative Heating Surface (sq ft / m2)5234 / 486.254666 / 433.64
Superheating Surface (sq ft / m2)1341 / 124.581085 / 100.84
Combined Heating Surface (sq ft / m2)6575 / 610.835751 / 534.48
Evaporative Heating Surface/Cylinder Volume229.50220.03
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation16,72015,260
Same as above plus superheater percentage20,06418,159
Same as above but substitute firebox area for grate area81,73888,774
Power L115,11414,601
Power MT565.91583.15

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Wes Barris