Seaboard Air Line 2-10-2 "Santa Fe" Locomotives in the USA

The Seaboard Air Line took delivery of its first "Santa Fe" type locomotives in 1918 when it received ten from the Baldwin locomotive works. These ten 2-10-2s were designated as Class B and were given road numbers 2400 through 2409. They had 63" diameter drivers, 29" x 32" cylinders, a 190 psi boiler pressure, exerted 68,989 pounds of tractive effort and each weighed 334,000 pounds.

The SAL operated these as mainline freighters out of Hamlet that pulled trains to Charlotte and Rutherfordton. They encountered problems with counterbalancing 5 sets of drivers and were rebuilt with disks later.

In 1919, the USRA allocated fifteen "Santa Fe-Light" locomotives to the SAL. These locomotives were built by Baldwin and were designated as Class B-1 and assigned road numbers 2485 through 2499. They had 57" diameter drivers, 27" x 32" cylinders, a 200 psi boiler pressure, exerted 69,575 pounds of tractive effort and each weighed 352,000 pounds.

The SAL acted to correct this counterbalancing by switching the drivers to disks. This solved the problem and in fact these USRA 2-10-2s outlasted the Class Bs which were considered to be better performers before the drivers were changed on the B-1s.

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


ClassQty.Road NumbersYear BuiltBuilderNotes
B102400-24091918BaldwinNumbers 2400-2409 scrapped between 1948 and 1951.
B-1152485-24991919BaldwinUSRA allocated .Santa Fe-Light. locomotives. Numbers 2485-2499 scrapped between 1950 and 1953.

Class Details by Steve Llanso of Sweat House Media

Class B (Locobase 9378)

Data from SAL 1929 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Vol 55, pp. 408+. (Thanks to Chris Hohl for pointing a valve gear change; later research by Locobase modified the original attribution of Walschaert gear.) Baldwin works numbers were 47802, 47867, 47923, 47946 in February 1918; 48072-48073, 48197-48198 in March and 48288-48289 in April.

These were not USRA Santa Fes (for those SAL engines, see Locobase 5008), but a somewhat smaller design with taller drivers. Direct heating surface area included 28 sq ft (2.6 sq m) of arch tubes and 102 sq ft (9.5 sq m) in the sizeable combustion chamber. The latter figure would later be trimmed to 68 sq ft (6.3 sq m).

The SAL operated these as mainline freighters out of Hamlet that pulled trains to Charlottesville and Rutherfordton over a road that included 12 degrees (radii of 478 feet/145.7 sq m). Like the B-1s, however, these encountered problems with counterbalancing five sets of drivers. The 1948 diagram book shows that some time after 1929 engines 2401-2402, 2406-2407, and 2409 were rebuilt with disks and fitted with Baker valve gear (a change from Southern gear).

NB: Originally Locobase presented the superheater surface area as an estimate. Comparing this design to similar boilers in other locomotives in Locobase, the editor came up with 1,075 sq ft. Later reference to the Baldwin specification showed that he was only 3 sq ft off.

Class B1 (USRA) (Locobase 5009)

Much of the data comes from [] for 1929 locomotive diagrams; and DeGolyer, Volume 58, pp. 134+. (Thanks to Chris Hohl for spotting the valve gear change in later photographs.) Works numbers were 52121 in July 1919 and 52158-52162, 52184-52187, 52220-52224 in August.

USRA light Santa Fes (Locobase 89) delivered with 14" (356 mm) piston valves. Firebox heating surface then included 34 sq ft (3.15 sq m) from five 3" (76.2 mm) arch tubes and 110 sq ft (10.22 sq m) in the combustion chamber. A measure of the material demanded by a relatively large firebox in 1918 is a specification for 920 flexible staybolts ("Tate, or a bolt of similar design") "to be applied in combustion chamber water space and in the breaking zone of the fire box." Exceptions to this layout were the use of hollow bolts in the bottom row of the firebox and the use of rigid bolts "in lower portion of combustion chamber, beginning about 30 degrees below horizontal center line."

In keeping with the USRA committtee's desire to include up-to-date features, the order specified a Duplex stoker for the firebox and Franklin Railway Supply Company's Ragonnet power reverser gear

Albert M. Langley, Jr and W. Forrest Beckum, Jr (in Drury (1993)) note were found to be "slow and hard on the track and were banished to the Atlanta-Birmingham line."

Langley and Beckum added, however, that later efforts to change the counterbalancing while switching the drivers to disks seem to have paid off. Also, the entire class was refitted with different valve gear. Baker gear was installed on 2485-2486, 2488, 2492, 2494, 2500 and Walschaert appeared on 2489-2491, 2493, and 2406-2408.

In fact, these USRAs retired several years after the initially more satisfactory Bs, running until 1950-1953.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassBB1 (USRA)
Locobase ID9378 5009
RailroadSeaboard Air Line (SAL)Seaboard Air Line (SAL)
Number in Class1515
Road Numbers400-409/2400-2409485-499/2485-2499
Number Built1515
Valve GearSouthernSouthern
Locomotive Length and Weight
Driver Wheelbase (ft / m)22.50 / 6.8621 / 6.40
Engine Wheelbase (ft / m)41.50 / 12.6540.33 / 12.29
Ratio of driving wheelbase to overall engine wheelbase 0.54 0.52
Overall Wheelbase (engine & tender) (ft / m)79.52 / 24.2475.96 / 23.15
Axle Loading (Maximum Weight per Axle) (lbs / kg)52,000 / 23,58756,500 / 25,628
Weight on Drivers (lbs / kg)240,000 / 108,862276,000 / 125,192
Engine Weight (lbs / kg)334,000 / 151,500352,000 / 159,665
Tender Loaded Weight (lbs / kg)194,000 / 87,997193,000 / 87,543
Total Engine and Tender Weight (lbs / kg)528,000 / 239,497545,000 / 247,208
Tender Water Capacity (gals / ML)10,000 / 37.8810,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)17 / 1617 / 16
Minimum weight of rail (calculated) (lb/yd / kg/m)80 / 4092 / 46
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160057 / 1448
Boiler Pressure (psi / kPa)190 / 13.10200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)29" x 32" / 737x81327" x 32" / 686x813
Tractive Effort (lbs / kg)68,989 / 31292.9269,575 / 31558.73
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.48 3.97
Heating Ability
Tubes (number - dia) (in / mm)207 - 2.25" / 57247 - 2.25" / 57
Flues (number - dia) (in / mm)42 - 5.5" / 14045 - 5.5" / 140
Flue/Tube length (ft / m)21 / 6.4020.50 / 6.25
Firebox Area (sq ft / m2)375 / 34.84373 / 34.65
Grate Area (sq ft / m2)70.40 / 6.5479.30 / 7.37
Evaporative Heating Surface (sq ft / m2)4190 / 389.264666 / 433.48
Superheating Surface (sq ft / m2)1078 / 100.151085 / 100.80
Combined Heating Surface (sq ft / m2)5268 / 489.415751 / 534.28
Evaporative Heating Surface/Cylinder Volume171.30219.99
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13,37615,860
Same as above plus superheater percentage16,05118,873
Same as above but substitute firebox area for grate area85,50088,774
Power L112,86014,598
Power MT590.65583.03

  • 2849 (Harold K. Vollrath Collection)
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