Data from John Garner's comprehensive site at [] ...(October 2002; last accessed 12 June 2025) Works numbers were 278, 282, 281, 279 in 1873.
Identical to the F class 0-6-0 saddle-tankers in running gear and boiler, these engines differed in the wheel arrangement and tank. The 4-4-0 layout meant a faster run with a light train, perhaps, but also less hauling capacity.
Charles Rous-Marten remarked that they were kept on "inferior duty" and weren't well liked.. The saddle tank in this class wrapped over the boiler; the steam dome sat on top.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | G |
| Locobase ID | 5172 |
| Railroad | New Zealand Railways |
| Country | New Zealand |
| Whyte | 4-4-0ST |
| Number in Class | 4 |
| Road Numbers | 55-58 |
| Gauge | 3'6" |
| Number Built | 4 |
| Builder | Black, Hawthorn |
| Year | 1873 |
| Valve Gear | Walschaert |
| 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) | 29,568 / 13,412 |
| Engine Weight (lbs / kg) | 45,920 / 20,829 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 25 / 12.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 36 / 914 |
| Boiler Pressure (psi / kPa) | 132 / 910 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 10.5" x 18" / 267x457 |
| Tractive Effort (lbs / kg) | 6185 / 2805.47 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.78 |
| 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) | 9 / 0.84 |
| Evaporative Heating Surface (sq ft / m2) | 485 / 45.07 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 485 / 45.07 |
| Evaporative Heating Surface/Cylinder Volume | 268.85 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1188 |
| Same as above plus superheater percentage | 1188 |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |