Seaboard Air Line 2-8-8-2 "Chesapeake" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class A (Locobase 15148)

Data from summary prepared by Chris Hohl and emailed to Locobase April 2013 and Albert M Langley, Jr and W Forrest Beckum, Jr, "Seaboard Air Line Railroad" in George H Drury, Guide to North American Steam Locomotives (Waukesha, WI: Kalmbach Books, 1993), p. 350. (Thanks to Chris Hohl for 21 November 2013 email noting an incorrect Locobase number for the B&O conversions.)

Langley and Beckum say that the Seaboard wanted pull fast freights between Richmond and Hamlet, NC and ordered these Mallets.

But they proved to be too big for the Seaboard's needs, so the SAL sold the As to the Baltimore & Ohio. The B&O took off the trailing truck and converted the designs to simple-expansion EL-6a; see Locobase 3556.

Specifications by Steve Llanso of Sweat House Media
Locobase ID15148
RailroadSeaboard Air Line (SAL)
Number in Class16
Road Numbers500-515
Number Built16
Valve GearSouthern
Locomotive Length and Weight
Driver Wheelbase15.46'
Engine Wheelbase53.33'
Ratio of driving wheelbase to overall engine wheebase 0.29
Overall Wheelbase (engine & tender)98.27'
Axle Loading (Maximum Weight per Axle)
Weight on Drivers380000 lbs
Engine Weight497000 lbs
Tender Light Weight219000 lbs
Total Engine and Tender Weight716000 lbs
Tender Water Capacity12000 gals
Tender Fuel Capacity (oil/coal)20 tons
Minimum weight of rail (calculated)79 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter63"
Boiler Pressure210 psi
High Pressure Cylinders (dia x stroke)26.5" x 32"
Low Pressure Cylinders (dia x stroke)42" x 32" (2)
Tractive Effort91082 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.17
Heating Ability
Firebox Area
Grate Area88 sq. ft
Evaporative Heating Surface5950 sq. ft
Superheating Surface1460 sq. ft
Combined Heating Surface7410 sq. ft
Evaporative Heating Surface/Cylinder Volume291.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation18480
Same as above plus superheater percentage22176
Same as above but substitute firebox area for grate area0
Power L10
Power MT0


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