Baltimore & Ohio 0-8-0 "Switcher" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class Dragon (Locobase 1022)

Data from Zerah Colburn, The Locomotive Engine (1851) and Joseph Snowden Bell, The Early Motive Power of the Baltimore & Ohio (1912) . See also Snowden Bell's long article in the October 1922 Railway and Locomotive Engineering, pp. 277-280. Works number was 325.

First of six Baldwin-built freight locomotives with inclined cylinders and a "flexible-beam" truck that allowed the engine to negotiate tighter curves. This was a parallelogram arrangement that let one pair of drivers (usually the front axle) move right while the next pair (the second axle) simultaneously slid left (e.g.); the 3rd and 4th axles were fixed in the frame.

Two other locomotives (Memnon & Saturn) were built by Newcastle Manufacturing and 3 -- Hero, Giant, & Lion -- by the B&O itself. Bell's recollection of these engines as of 1857 was that they did not use flexible-beam trucks.

Class Eight-wheel freight (Locobase 8808)

Data from Zerah Colburn, The Locomotive Engine (1851) and Joseph Snowden Bell, The Early Motive Power of the Baltimore & Ohio (1912) .

Four arrived with names: Hero 1848, Giant 1849, and Lion and Tiger in 1850. The first threeThe first three locomotives were delivered with 17" (508 mm) diameter cylinders, but were rebuilt in 1857-1858. Bell described the horizontal cylinders bolted "to a flat-sided smokebox, the bed plate or saddle not then being known. The valves were operated through drop-hook gear, which required ...conections [sic] for starting bars. "Solid-ended" side rods made their first appearance, apparently, Bell supposed, because Thatcher Perkins invented them.

Bell's elevation drawing showed a straight-barrelled boiler over four sets of closely spaced drivers, large cab, perfectly cyindrical drum for a steam dome with a tall safety valve, small box for the throttle closer to the smokebox, the latter topped by an enormous funnel-shaped, spark-arresting stack.

These were among the last large class of 0-8-0s supplied to the B & O.

Class Saturn (Locobase 8807)

Data from Zerah Colburn, The Locomotive Engine (1851) and Joseph Snowden Bell, The Early Motive Power of the Baltimore & Ohio (1912) .

This class followed Baldwin's flexible-beam "Dragon", but apparently did not have the parallelogram arrangement themselves. Two locomotives (Memnon & Saturn) were built by New Castle Manufacturing in New Castle, Del and 3 -- Hero, Giant, & Lion -- by the B&O itself.

Class Susquehanna (Locobase 2552)

Data from John H White, Jr, A History of the American Locomotive: Its Development: 1830-1880 (New York: Dover Publications, 1979 - original publication in 1968).

See White for an extensive discussion of Ross Winans' Camel design. A constant thread is the novelty of many of his choices, all made to arrive at greater simplicity and ruggedness, according to Winans. But, White comments, "Against these claims of superiority came equally valid claims of clumsiness and inconvenience." For those criticisms and a general impression of Winans as hot-headed and stubborn, see the B&O's account of its exchanges with Winans in Papers Relative to the Recent Contracts for Motive Power by the Baltimore and Ohio Rail Road Co. and the Reports of the Officers of the Different Departments on the Relative Advantages of the Winans Camel Engine, and the Ten Wheel Engine for the Various Branches of their Service (Baltimore: James Lucas & Son, 1857).

The camel design was among the oddest to be built in large (320) numbers. (An article in the December 1891 Railway Master Mechanic -- reprinted on -- says 219 were produced from June 1848 to February 1857.)

A straight boiler of significant girth came ahead of a large, sloping firebox. The engineer's position was established on top of the boiler in a structure reminiscent of a howdah, the shooting blind often placed on elephants in India. The engineer shared the house with the tall steam dome which was positioned over the first driver set, just behind the odd stack, which had a pipe in front of the exhaust chimney to catch cinders.

The boiler was dangerously weakened by large holes for the steam dome and coal chutes, the firebox was large and encumbered by hoppers (to ensure coal got to the front of the grate), the drawbar connection was prone to failure, accessories like the feed-water pump were poorly placed, the cylinders weakly mounted, the valve motion complicated and difficult to keep aligned.

In the 1857 Papers relative ... volume, p.30 offers a 6 February 1857 reply from the B&O's supervisor of machinery J R Smith in which he conceded that "These engines, WHEN THEY CAN BE KEPT FROM LEAKING [Smith's all-caps], which is seldom done, burn the Cumberland coal very successfully." He then set out the design's shortcomings:

"I disapprove of the manner in which these engines take their draft, causing the furnaces to break off from the cylinder part of the boiler. I also disapprove fo the great length of the furnace, whcn a shorter one will make a sufficient quantity of steam. The length of furnace and great distance from center of back driver to center of truck of the tender gives a great leverage, causing the engine to press hard against the inside rail when passing around curves, making it more liable to leave the track than an engine provided with a truck."

The Camel's builder, says White, "is redeemed, in part, by the service performed by these unique machines." For their time, he notes, they could perform prodigies of slow-freight haulage. The 1891 article writer agreed, noting they could pull 160-ton freight trains up a grade of better than 2%.

When contrasted with the Ten-wheelers, an arrangement to which Winans was adamantly opposed, the B&O's supervisor of machinery J R Smith wrote (p. 30) a succinct summary of their differences: "The Camel engine will draw a heavier load than the Ten-wheel engine, but the latter is more certain of making the trip, and when it becomes necessary to run at greater speed than ordinary, is best calculated to perform that speed with safety."

Principal Dimensions by Steve Llanso of Sweat House Media
ClassDragonEight-wheel freightSaturnSusquehanna
Locobase ID1022 8808 8807 2552
RailroadBaltimore & Ohio (B&O)Baltimore & Ohio (B&O)Baltimore & Ohio (B&O)Baltimore & Ohio (B&O)
Number in Class176
Road Numbers5154, 63-64, 67, 72, 77, 8354, 56-57, 63-64
Number Built176
BuilderM W BaldwinB& OseveralRoss Winans
Valve Geardrop-hook
Locomotive Length and Weight
Driver Wheelbase (ft / m)11.25 / 3.4311.2511.25 / 3.43
Engine Wheelbase (ft / m)11.25 / 3.4311.25 / 9.4030.83 / 9.4011.25 / 9.40
Ratio of driving wheelbase to overall engine wheebase111
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)41,000 / 18,59757,400 / 26,03647,000 / 21,31954,000 / 24,494
Engine Weight (lbs / kg)41,000 / 18,59757,400 / 26,03647,000 / 21,31954,000 / 24,494
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)1900 / 7.20
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)5 / 4.50
Minimum weight of rail (calculated) (lb/yd / kg/m)17 / 8.5024 / 1220 / 1023 / 11.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)43 / 109243 / 109243 / 109243 / 1092
Boiler Pressure (psi / kPa)65 / 4.5065 / 4.5065 / 4.5090 / 6.20
High Pressure Cylinders (dia x stroke) (in / mm)14.5" x 18" / 368x45720" x 22" / 483x55917" x 22" / 432x55919" x 22" / 483x559
Tractive Effort (lbs / kg)4863 / 2205.8211,307 / 5128.788169 / 3705.4014,129 / 6408.81
Factor of Adhesion (Weight on Drivers/Tractive Effort) 8.43 5.08 5.75 3.82
Heating Ability
Firebox Area (sq ft / m2)87.50 / 8.1386
Grate Area (sq ft / m2)18 / 1.6710.81 / 123.50 / 2.18
Evaporative Heating Surface (sq ft / m2)1072 / 99.631000 / 92.941000 / 92.94
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1072 / 99.631000 / 92.941000 / 92.94
Evaporative Heating Surface/Cylinder Volume134.01173.02138.51
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11707032115
Same as above plus superheater percentage11707032115
Same as above but substitute firebox area for grate area56887740
Power L18791278
Power MT135.04208.70

All material Copyright ©
Wes Barris