Mohawk & Hudson / Utica & Schenectady 4-2-0 "Jervis" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class Alert (Locobase 1021)

Source (Kinert, 1962) says it had 108 boiler tubes and was one of the first Baldwin locomotives have both a cab and a headlight. Works numbers included 29 in April 1836 and 35 in June and 36-38 in July . (May have included 33-34, but Locobase can't be sure.) See also Angus Sinclair, Development of the locomotive engine ... (New York: D Van Nostrand, 1907), p. 364.

Alert began with the U & S, but later operated on the Galena & Chicago Union, where it was renamed Pioneer, and the Chicago, Burlington & Quincy until it was donated to the Chicago Historical Society. During its MC years, says Angus Sinclair, the locomotive's running gear underwent some modifications: "As originally built it had a single fixed eccentric for each cylinder with two arms extending backwards having drop hooks to engage with a pin on a rocker arm which actuated the valve rod. That motion was removed and double eccentrics with V-hook put in its place, the motion now found on the engine"

All of the others in the class were scrapped in the early 1850s.

Class Brother Jonathan (Locobase 2537)

This was the first steam locomotive anywhere to have a leading bogie, an important innovation that soon led to the ubiquitous 4-4-0 "American" type. According to Staufer (1967), the relatively large grate was designed to burn anthracite coal.

Originally known as the Experiment, a rebuild which included a new wood-burning firebox led to the engine's redubbing. (Brother Jonathan was the American everyman of his day.) Designed by John B. Jarvis, Brother Jonathan proved quite successful and was itself converted to a 4-4-0 years later.

Specifications by Steve Llanso of Sweat House Media
ClassAlertBrother Jonathan
Locobase ID1021 2537
RailroadUtica & Schenectady (NYC)Mohawk & Hudson (NYC)
Number in Class11
Road Numbers1, 5-8 /
Number Built11
BuilderMatthias BaldwinWest Point Foundry
Valve GearV-hook
Locomotive Length and Weight
Driver Wheelbase
Engine Wheelbase24.45'
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers24120 lbs7000 lbs
Engine Weight24120 lbs14000 lbs
Tender Light Weight
Total Engine and Tender Weight
Tender Water Capacity
Tender Fuel Capacity (oil/coal)
Minimum weight of rail (calculated)40 lb/yard12 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter54"60"
Boiler Pressure100 psi50 psi
Cylinders (dia x stroke)10" x 18"9.5" x 16"
Tractive Effort2833 lbs1023 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 8.51 6.84
Heating Ability
Firebox Area
Grate Area14.17 sq. ft
Evaporative Heating Surface
Superheating Surface
Combined Heating Surface00
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation0709
Same as above plus superheater percentage0709
Same as above but substitute firebox area for grate area00
Power L100
Power MT00


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