Baltimore & Ohio 2-10-2 "Santa Fe" Type Locomotives

Class S (Locobase 1036)

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.

Class S-1a (Locobase 73)

Data from 1930 Locomotive Cyclopedia tables and from 1954 B & O locomotive diagram assortment supplied in May 2005 by Allen Stanley from his extensive collection.

This class of 125 freight haulers came in 1923-1926 from Baldwin and Lima. 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	1926
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	21648	23232
Same as above but substitute firebox area for grate area	88068	99000
Power L1	14627	18585
Power MT	478.73	588.98