Jamaican Government 2-8-2 Locomotives in Jamaica


Class Details by Steve Llanso of Sweat House Media

Class H (Locobase 12786)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 36, p. 271. See also P C Dewhurst, "The Jamaica Government Railway and its Locomotives", Locomotive Magazine, Volume 25 (15 December 1919), p.211. Works numbers were 36163-36164 in February 1911.

These were bigger, longer elaborations of the Twelve-wheeler Baldwin design that entered JGR service in 1907 (Locobase 12786). The specs for this pair had a long note about the placement of fire brick that shows how carefully such details were tweaked and focus on lessons learned: "Hereafter ...Company [JGR? or Baldwin?] changed with good results the arrangement of fire brick, making it rise from below tubes to a point rather above firebox door. Hereafter - Lower end of firebricks to be placed just below the bottom row of boiler tubes and the upper end to be a little above the fire door. Letter 6-5-11 from W A S Richmond."

A similar note was entered concerning the castings for the center pin crossties that took the load of the leading truck, which had broken in service. These were "hereafter" to be "...strengthened by increasing thickness and adding iron ribs."

Delivering the locomotives with a pressure setting of 190 psi (13.1 bar) meant a low factor of adhesion and the railway soon reduced it to 180 psi.


Class H-1 (Locobase 12788)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 54, p. 275-289. Works numbers were 41059-41061 in January 1914 and 41298 in April.

A small, superheated Mikado design that duplicated many of the dimensions of the 1911 Mikes (see Locobase 12787), but sacrificed several dozen small tubes for a useful amount of superheat. The ratio between small and large tubes changed when nine of the small tubes were removed, Tube count decreased from 173 to 164, evaporative heating surface, which had been 2,239 sq ft (208.09 sq m) went down Steam admission came through 11" (279 mm) piston valves.

See the "Hereafter" notes on specs pages 281 and 289 of Baldwin volume 54 for examples of the kind of tweaking an engine's design might inspire once it entered service.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassHH-1
Locobase ID12786 12788
RailroadJamaican GovernmentJamaican Government
CountryJamaicaJamaica
Whyte2-8-22-8-2
Number in Class24
Road Numbers35-36 / 35, 3437-40/37-39, 36
GaugeStdStd
Number Built24
BuilderBaldwinBaldwin
Year19111914
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.75 / 3.8912.75 / 3.89
Engine Wheelbase (ft / m)27.50 / 8.3827.50 / 8.38
Ratio of driving wheelbase to overall engine wheelbase 0.46 0.46
Overall Wheelbase (engine & tender) (ft / m)52.04 / 15.86
Axle Loading (Maximum Weight per Axle) (lbs / kg)28,000 / 12,701
Weight on Drivers (lbs / kg)109,200 / 49,532120,000 / 54,431
Engine Weight (lbs / kg)148,904 / 67,542159,000 / 72,121
Tender Loaded Weight (lbs / kg)84,000 / 38,10276,000 / 34,473
Total Engine and Tender Weight (lbs / kg)232,904 / 105,644235,000 / 106,594
Tender Water Capacity (gals / ML)4200 / 15.913600 / 13.64
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)7 / 65 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)46 / 2350 / 25
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)46 / 116846 / 1168
Boiler Pressure (psi / kPa)180 / 12.40190 / 13.10
High Pressure Cylinders (dia x stroke) (in / mm)19" x 26" / 483x66019" x 26" / 483x660
Tractive Effort (lbs / kg)31,219 / 14160.7232,953 / 14947.25
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.50 3.64
Heating Ability
Tubes (number - dia) (in / mm)270 - 2" / 51164 - 2" / 51
Flues (number - dia) (in / mm)24 - 5.375" / 137
Flue/Tube length (ft / m)17.25 / 5.2617 / 5.18
Firebox Area (sq ft / m2)130 / 12.08136 / 12.63
Grate Area (sq ft / m2)37.40 / 3.4737.40 / 3.47
Evaporative Heating Surface (sq ft / m2)2556 / 237.462159 / 200.58
Superheating Surface (sq ft / m2)473 / 43.94
Combined Heating Surface (sq ft / m2)2556 / 237.462632 / 244.52
Evaporative Heating Surface/Cylinder Volume299.57253.04
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation67327106
Same as above plus superheater percentage67328385
Same as above but substitute firebox area for grate area23,40030,491
Power L1518512,115
Power MT418.72890.30

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