Baltimore & Ohio 4-2-0 "Jervis" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class Lafayette (Locobase 2542)

Based on the Philadelphia & Columbia's Washington County Farmer, this engine was a typical William Norris design. It had the Bury "haystack" boiler, a bar (vs plate) frame, and a valve gear that was cam-operated. Hollingsworth (1982) notes that later engines in the class had a more typical "gab" motion.

Hollingsworth contends that these engines were a great success, being reliable and showing markedly reduced fuel consumption.

Specifications by Steve Llanso of Sweat House Media
Locobase ID2542
RailroadBaltimore & Ohio (B&O)
Number in Class8
Road Numbers
Number Built8
BuilderWilliam Norris
Valve Gear
Locomotive Length and Weight
Driver Wheelbase
Engine Wheelbase
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender)30.27'
Axle Loading (Maximum Weight per Axle)11200 lbs
Weight on Drivers11200 lbs
Engine Weight44000 lbs
Tender Light Weight
Total Engine and Tender Weight
Tender Water Capacity540 gals
Tender Fuel Capacity (oil/coal)1.1 tons
Minimum weight of rail (calculated)19 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter48"
Boiler Pressure60 psi
Cylinders (dia x stroke)10.5" x 18"
Tractive Effort2109 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.31
Heating Ability
Firebox Area
Grate Area 8.60 sq. ft
Evaporative Heating Surface394 sq. ft
Superheating Surface
Combined Heating Surface394 sq. ft
Evaporative Heating Surface/Cylinder Volume218.41
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation516
Same as above plus superheater percentage516
Same as above but substitute firebox area for grate area0
Power L10
Power MT0


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