Interstate 2-8-8-2 "Chesapeake" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class 20 (Locobase 6441)

Data based on (visited 26 Dec 2004). The diagram indicates that these were based on the USRA heavy articulated, but were intended to negotiate 22-deg curves. As a result, each set of drivers had a 3" longer wheelbase and the engine wheelbase measured a total of 3" longer.

The diagram is less informative about heating surfaces, giving only the total of evaporative and superheater combined as 8,332 sq ft. This is 737 sq ft more than the USRA standard.

Specifications by Steve Llanso of Sweat House Media
Locobase ID6441
RailroadInterstate (IRR)
Number in Class2
Road Numbers20-21
Number Built2
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase15.75'
Engine Wheelbase58'
Ratio of driving wheelbase to overall engine wheebase 0.27
Overall Wheelbase (engine & tender)94.25'
Axle Loading (Maximum Weight per Axle)62000 lbs
Weight on Drivers486500 lbs
Engine Weight541000 lbs
Tender Light Weight209200 lbs
Total Engine and Tender Weight750200 lbs
Tender Water Capacity12000 gals
Tender Fuel Capacity (oil/coal)16 tons
Minimum weight of rail (calculated)101 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter57"
Boiler Pressure240 psi
High Pressure Cylinders (dia x stroke)25" x 32"
Low Pressure Cylinders (dia x stroke)39" x 32" (2)
Tractive Effort101465 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.79
Heating Ability
Firebox Area
Grate Area96.50 sq. ft
Evaporative Heating Surface
Superheating Surface
Combined Heating Surface0
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation23160
Same as above plus superheater percentage23160
Same as above but substitute firebox area for grate area0
Power L10
Power MT0

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