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 ID15,148
RailroadSeaboard Air Line (SAL)
Number in Class16
Road Numbers500-515
Number Built16
Valve GearSouthern
Locomotive Length and Weight
Driver Wheelbase (ft)15.46
Engine Wheelbase (ft)53.33
Ratio of driving wheelbase to overall engine wheebase 0.29
Overall Wheelbase (engine & tender) (ft)98.27
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)380,000
Engine Weight (lbs)497,000
Tender Loaded Weight (lbs)219,000
Total Engine and Tender Weight (lbs)716,000
Tender Water Capacity (gals)12,000
Tender Fuel Capacity (oil/coal) (gals/tons)20
Minimum weight of rail (calculated) (lb/yd)79
Geometry Relating to Tractive Effort
Driver Diameter (in)63
Boiler Pressure (psi)210
High Pressure Cylinders (dia x stroke) (in)26.5" x 32"
Low Pressure Cylinders (dia x stroke) (in)42" x 32"
Tractive Effort (lbs)91,082
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.17
Heating Ability
Firebox Area (sq ft)
Grate Area (sq ft)88
Evaporative Heating Surface (sq ft)5950
Superheating Surface (sq ft)1460
Combined Heating Surface (sq ft)7410
Evaporative Heating Surface/Cylinder Volume291.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation18,480
Same as above plus superheater percentage22,176
Same as above but substitute firebox area for grate area
Power L1
Power MT


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