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

Class Details by Steve Llanso of Sweat House Media

Class Fb (Locobase 5171)

Data from Howell, Comparative Statistics of the Australasian Railways, Journal of the Royal Statistical Society, March 1899, pp. 98-99; and John Garner's [], last accessed 7 September 2008.

These radial tanks were rebuilds of rebuilds. At first, in 1892, the NZGR shops enlarged the F class with larger cylinders and side tanks replacing the saddle tank; these were the Fa. In 1897, a new locomotive was built to a modified design that was further modified with a trailing axle and a piston valve set into the slide-valve chest. In 1902, six more followed from Addington.

Thirteen more Fb were created when Fa were modified beginning in 1903, after which all 20 locomotives were designated Fa. The builder replaced the slide valves with piston valves and internal axles bearings in the trailing truck with outside journal boxes.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID5171
RailroadNew Zealand Government Railways
CountryNew Zealand
Number in Class20
Road Numbers
Number Built8
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)10.50 / 3.20
Engine Wheelbase (ft / m)16.50 / 5.03
Ratio of driving wheelbase to overall engine wheelbase 0.64
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)56,448 / 25,604
Engine Weight (lbs / kg)65,632 / 29,770
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)65,632 / 29,770
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)31 / 15.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)36.50 / 927
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)12" x 18" / 305x457
Tractive Effort (lbs / kg)9658 / 4380.80
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.84
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)10.70 / 0.99
Evaporative Heating Surface (sq ft / m2)530 / 49.26
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)530 / 49.26
Evaporative Heating Surface/Cylinder Volume224.94
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1712
Same as above plus superheater percentage1712
Same as above but substitute firebox area for grate area
Power L1
Power MT

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