Firebox heating surface included 65 sq ft of combustion chamber and 35 sq ft of "water tubes."
First Santa Fes on the B&O, these 31 engines were the archetypal slow-moving weight lifters that operated on heavy grades. One impressive feature was the 16" piston valves supplied by that ample boiler and grate. The later S-1as had taller drivers and could run faster.
The class was known as the "Big Six," probably borrowing the nickname from the big New York Giants pitcher Christy Mathewson, whose ability to "put out fires" originally earned him comparison with a well-known New York City fire engine.
The last S-1s retired in 1953.
This class of 125 freight haulers came in 1923-1926 from Baldwin (75) and Lima (50). Firebox had combustion chamber and the total heating surface included 38 sq ft of arch tubes and 67 sq ft of combustion chamber. Drury (1993) comments that unlike most 2-10-2s, which were low-speed engines "that could pull anything, given enough time," the B&O's were fast as well as powerful. He notes that the larger 64" drivers allowed more effective counterbalancing.
(The class was known as the "Big Six," from the number of the lead engine, but possibly borrowing the nickname from the big New York Giants pitcher Christy Mathewson, whose ability to "put out fires" originally earned him comparison with a well-known New York City fire engine.)
The last S-1a retired in 1959.
| Specifications | ||
|---|---|---|
| Class | S | S-1a |
| Locobase ID | 1036 | 73 |
| Railroad | Baltimore & Ohio (B&O) | Baltimore & Ohio (B&O) |
| Whyte | 2-10-2 | 2-10-2 |
| Road Numbers | 6000-6030 | 6100-6224 |
| Gauge | Std | Std |
| Builder | Baldwin | Several |
| Year | 1914 | 1923 |
| Valve Gear | Walschaert | Baker |
| Locomotive Length and Weight | ||
| Driver Wheelbase | 21' | 22.30' |
| Engine Wheelbase | 40.25' | 42.90' |
| Ratio of driving wheelbase to overall engine wheebase | 0.52 | 0.52 |
| Overall Wheelbase (engine & tender) | 76.50' | 89.90' |
| Axle Loading (Maximum Weight per Axle) | 68300 lbs | 69830 lbs |
| Weight on Drivers | 336800 lbs | 347830 lbs |
| Engine Weight | 406000 lbs | 436810 lbs |
| Tender Light Weight | 178400 lbs | 298400 lbs |
| Total Engine and Tender Weight | 584400 lbs | 735210 lbs |
| Tender Water Capacity | 10000 gals | 15800 gals |
| Tender Fuel Capacity (oil/coal) | 16 tons | 23 tons |
| Minimum weight per yard of rail on which locomotive could run | 112 lb rail | 116 lb rail |
| Geometry Relating to Tractive Effort | ||
| Driver Diameter | 58" | 64" |
| Boiler Pressure | 205 psi | 220 psi |
| Cylinders (dia x stroke) | 30" x 32" | 30" x 32" |
| Tractive Effort | 86524 lbs | 84150 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.89 | 4.13 |
| Heating Ability | ||
| Firebox Area | 358 sq. ft | 375 sq. ft |
| Grate Area | 88 sq. ft | 88 sq. ft |
| Evaporative Heating Surface | 5573 | 5251 |
| Superheating Surface | 1329 | 1512 |
| Combined Heating Surface | 6902 | 6763 |
| Evaporative Heating Surface/Cylinder Volume | 212.87 | 200.57 |
| Computations Relating to Power Output (More Information) | ||
| Robert LeMassena's Power Computation | 18040 | 19360 |
| Same as above plus superheater percentage | 21468 | 23619 |
| Same as above but substitute firebox area for grate area | 87334 | 100650 |
| Power L1 | 14627 | 18585 |
| Power MT | 478.73 | 588.98 |
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