Connecticut & Passumpsic 4-4-0 "American" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class Addison Gilmore (Locobase 13551)

Data from table entitled "Table of Dimensions of the Locomotives" in New England Association of Railway Superintendents, Report of the Trials of Locomotive Engines Made Upon 1st and 2nd October, 1851 (Boston: B J Yerrinton, Printers, 1852), p. 16.

This locomotive had its boiler pressure measured at 144 psi by the committee overseeing the October 1851 trials. Despite the juiced-up power, this high-drivered engine took almost 2 minutes more to finish the 9-mile course than did its identically named rival (Locobase 13519).

Although the specs didn't include areas, a calculation of tube area shows that this was one of the largest locomotives in the competition. Given that the contestants represented New England railroad practice, Locobase supposes this

Specifications by Steve Llanso of Sweat House Media
ClassAddison Gilmore
Locobase ID13551
RailroadConnecticut & Passumpsic
Number in Class1
Road Numbers
Number Built1
Valve GearV-hook
Locomotive Length and Weight
Driver Wheelbase
Engine Wheelbase
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers
Engine Weight46320 lbs
Tender Light Weight
Total Engine and Tender Weight
Tender Water Capacity
Tender Fuel Capacity (oil/coal)
Minimum weight of rail (calculated)0
Geometry Relating to Tractive Effort
Driver Diameter78"
Boiler Pressure124 psi
Cylinders (dia x stroke)16" x 20"
Tractive Effort6919 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort)
Heating Ability
Firebox Area
Grate Area
Evaporative Heating Surface
Superheating Surface
Combined Heating Surface0
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation0
Same as above plus superheater percentage0
Same as above but substitute firebox area for grate area0
Power L10
Power MT


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