Boston & Lowell 4-2-0 "Jervis" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class Double Speeder (Locobase 13513)

Data from "Early Locomotive Works," Railroad Age Gazette, Volume XLV, No 16 (11 September 1908), p. 914. See also, last accessed 3 December 2011 and D K Minor (ed), "Boston And Lowell Railroad," American Railroad Journal and Advocate of Internal Improvements, Volume III, No 30 (2 August 1834), p. 469.

The early American journal of railroading proclaimed that the two engines being built at the Lowell shops, "....where the union of the best Yankee and foreign mechanical skill produces the highest perfection in machinery." (The second engine was to be named David Crockett in yet another example of the fame once owned by the Tennessee frontiersman.) Once the railroad was finished, said the ARJAII, and the two received "...the 'go ahead', it will be in earnest."

According to Wikipedia's extensive entry on the Boston & Lowell, the early roadbed was so rigid that the two locomotives that opened service on the line in 1835 took a terrible pounding from the lack of "give" and needed extensive repairs almost every night.

See David R Meyer, Networked Machinists: high-technology industries in Antebellum America (Baltimore: Johns Hopkins University Press, 2006), p. 115, in which he discusses the Locks and Canals Shops' role as an incubator of talent.

Class Essex (Locobase 13550)

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.

The St Clair was designed by the Essex's superintendent Caleb W Marvel. Locobase suspects that the Huron (later #21 of the O & LC) was a sister engine.

The O & LC would eventually merge with the Rutland.

NB: Boiler pressure and tube length both represent estimates.

Specifications by Steve Llanso of Sweat House Media
ClassDouble SpeederEssex
Locobase ID13513 13550
RailroadBoston & LowellBoston & Lowell
Number in Class11
Road Numbers
Number Built11
BuilderLowell Machine ShopEssex Company
Valve GearStephensonV-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 Drivers14500 lbs
Engine Weight23000 lbs48740 lbs
Tender Light Weight
Total Engine and Tender Weight
Tender Water Capacity
Tender Fuel Capacity (oil/coal)
Minimum weight of rail (calculated)24 lb/yard0
Geometry Relating to Tractive Effort
Driver Diameter60"72"
Boiler Pressure90 psi100 psi
Cylinders (dia x stroke)11" x 16"15" x 20"
Tractive Effort2468 lbs5313 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.88
Heating Ability
Firebox Area61.31 sq. ft
Grate Area 6.40 sq. ft10.75 sq. ft
Evaporative Heating Surface300 sq. ft692 sq. ft
Superheating Surface
Combined Heating Surface300 sq. ft692 sq. ft
Evaporative Heating Surface/Cylinder Volume170.47169.17
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5761075
Same as above plus superheater percentage5761075
Same as above but substitute firebox area for grate area06131
Power L102929
Power MT0

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