Mohawk & Hudson / Utica & Schenectady 4-2-0 "Jervis" Locomotives in 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)

See also rjkitterman's deviantart blog entry at, last accessed 2 July 2017.

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.

Kitterman quotes from an effusive entry in the 1832 Journals of Ebenezer Mattoon Chamberlain, made after his arrival in Schenectady on 28 June 1832. Chamberlain was fully aware of the implications of his journey and expressed his awe in Olympian prose: "Among the astonishing inventions of man, surely that of the locomotive steam engine hath no secondary rank. By this matchless exercise of skill, we fly with a smooth and even course along once impassible barriers, the valleys are filled the mountains laid low, and distance seems annihilated."

Evincing many of the qualities of later railfans, Chamberlain continued" I took my seat as near as possible to the car containing the eninge, in order to examine more minutely the operation of this, to me, novel and stupendous specimen of human skill. Having thus, as if by some invisible agency flown the distance of 16 miles [25.75 km] in 40 minutes, at Schenectacy I took passage on the Hudson and Erie Canal for Buffalo."

So Chamberlain moved from the latest engineering marvel to the still-astonishing achievement of the Erie Canal.

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 (ft / m)
Engine Wheelbase (ft / m)24.45 / 7.45
Ratio of driving wheelbase to overall engine wheebase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)24,120 / 10,9417000 / 3175
Engine Weight (lbs / kg)24,120 / 10,94114,000 / 6350
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)40 / 2012 / 6
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 137260 / 1524
Boiler Pressure (psi / kPa)100 / 6.9050 / 3.40
High Pressure Cylinders (dia x stroke) (in / mm)10" x 18" / 254x4579.5" x 16" / 241x406
Tractive Effort (lbs / kg)2833 / 1285.031023 / 464.03
Factor of Adhesion (Weight on Drivers/Tractive Effort) 8.51 6.84
Heating Ability
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)14.17 / 1.32
Evaporative Heating Surface (sq ft / m2)
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)
Evaporative Heating Surface/Cylinder Volume
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation709
Same as above plus superheater percentage709
Same as above but substitute firebox area for grate area
Power L1
Power MT