Wellington & Manawatu 2-8-4 Locomotives in New_Zealand


Class Details by Steve Llanso of Sweat House Media

Class Jumbo / Wj (Locobase 2709)

Data from John Garner's New Zealand Railways Steam Locomotives ([], last accessed 16 December 2009) and from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 26, p. 212. Works number was 23596 in January 1904.

Garner comments: "If ever a locomotive was well named it was Jumbo, the most powerful, most 'cussed' and discussed engine on the Manawatu Railway." A rare 2-8-4 tank engine from an American builder, this locomotive served the suburban passenger traffic around Wellington. It was largely used as a pusher and developed so much power that it could bend its own bar frame.

After the WMR's absorption into the NZGR in 1908, #466 operated until March 1928.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassJumbo / Wj
Locobase ID2709
RailroadWellington & Manawatu
CountryNew Zealand
Whyte2-8-4T
Number in Class1
Road Numbers3 / 466
Gauge3'6"
Number Built1
BuilderBurnham, Williams & Co
Year1904
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)11.75 / 3.58
Engine Wheelbase (ft / m)29.42 / 8.97
Ratio of driving wheelbase to overall engine wheelbase 0.40
Overall Wheelbase (engine & tender) (ft / m)29.50 / 8.99
Axle Loading (Maximum Weight per Axle) (lbs / kg)22,050 / 10,002
Weight on Drivers (lbs / kg)85,120 / 38,610
Engine Weight (lbs / kg)120,064 / 54,460
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)120,064 / 54,460
Tender Water Capacity (gals / ML)1116 / 4.23
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.80 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)35 / 17.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)43 / 1092
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)17" x 20" / 432x508
Tractive Effort (lbs / kg)22,851 / 10365.05
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.73
Heating Ability
Tubes (number - dia) (in / mm)188 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)11.58 / 3.53
Firebox Area (sq ft / m2)94.70 / 8.80
Grate Area (sq ft / m2)16.50 / 1.53
Evaporative Heating Surface (sq ft / m2)1080 / 100.37
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1080 / 100.37
Evaporative Heating Surface/Cylinder Volume205.55
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3300
Same as above plus superheater percentage3300
Same as above but substitute firebox area for grate area18,940
Power L14238
Power MT439.06

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