New Zealand Government Railways 2-6-0 Locomotives in New_Zealand

Class Details by Steve Llanso of Sweat House Media

Class J (Locobase 5174)

Data from John Garner's comprehensive site at [] ... (October 2002). See also Charles Rous-Marten, "The New Zealand Railways 3 ft 6 in Gauge-Their Progress and Results for 1884-Their Locomotive Practice, and New Departures in that Department", No 24575, English Mechanic and World of Science, No. 1,063 (7 August 1885), pp. 499-500. Avonside produced six, Dubs four, Neilson five, Robert Stephenson & Company five, and Vulcan Foundry twelve.

Garner says these engines held two distinctions: they were the first New Zealand tender engines, and they were the only Moguls ever bought for the islands. Photos show a tall stack, sand boxes ahead and behind the slightly taller steam dome. The rear sand box sat on top of the Belpaire firebox. As small as the drivers were already, the running board included small splasher over the top portion of the first two drivers on each side.

Rous-Marten, then with the NZGR, noted that the majority of service that then constituted main line traffic were slow-speed mixed trains. He described their occasional runs on the Christchurch-Dunedin service as consisting of "slow expresses for 140 miles [225 km] and fast stopping-trains over 90 miles [145 km]." J-class engines averaged 30 mph (48 kph) over an alignment that included one in 100 (1%) gradients in both directions between Studholme Junction and Oxmarn

Four were later modified as W-class 2-6-2Ts and 11 others became Wa-class switchers.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID5174
RailroadNew Zealand Government Railways
CountryNew Zealand
Number in Class32
Road Numbers
Number Built32
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)9 / 2.74
Engine Wheelbase (ft / m)15.83 / 4.82
Ratio of driving wheelbase to overall engine wheelbase 0.57
Overall Wheelbase (engine & tender) (ft / m)33.45 / 10.20
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)39,200 / 17,781
Engine Weight (lbs / kg)47,040 / 21,337
Tender Loaded Weight (lbs / kg)38,080 / 17,273
Total Engine and Tender Weight (lbs / kg)85,120 / 38,610
Tender Water Capacity (gals / ML)360 / 1.36
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 0.60 / 1
Minimum weight of rail (calculated) (lb/yd / kg/m)22 / 11
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 1067
Boiler Pressure (psi / kPa)130 / 9
High Pressure Cylinders (dia x stroke) (in / mm)14" x 20" / 356x508
Tractive Effort (lbs / kg)10,313 / 4677.90
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.80
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)57 / 5.30
Grate Area (sq ft / m2)12 / 1.12
Evaporative Heating Surface (sq ft / m2)686 / 63.75
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)686 / 63.75
Evaporative Heating Surface/Cylinder Volume192.51
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1560
Same as above plus superheater percentage1560
Same as above but substitute firebox area for grate area7410
Power L12480
Power MT418.43

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