Information from "Davenport 0-4-0 ST--NZR Way & Works Branch" on John Garner's New Zealand Steam website at [], last accessed 29 October 2022. (Thanks to Harrison Hill for his 23 October 2022 inquiring about the PWD quartet.) Works numbers were 1862-1863 in January 1921.
This pair was slightly larger than the first two PWDs, which had 6" (152 mmm) x 10" (254 mm) cylinders and 20" (508 mm) drivers. All of them worked on PWD construction projects from 1921-1938. From 1938 , all four served the New Zealand Railways Ways and Works Department. Stored after World War II at the NZR's Otahuhu Railway Workshops, both went to the ferro-knacker's in 1954.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 728 |
| Locobase ID | 21101 |
| Railroad | Public Works Department |
| Country | New Zealand |
| Whyte | 0-4-0ST |
| Number in Class | 2 |
| Road Numbers | 728-729 |
| Gauge | 3'6" |
| Number Built | 2 |
| Builder | Davenport |
| Year | 1921 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 3.83 / 1.17 |
| Engine Wheelbase (ft / m) | 3.83 / 1.17 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | 3.83 / 1.17 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 20,160 / 9144 |
| Engine Weight (lbs / kg) | 20,160 / 9144 |
| 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) | 17 / 8.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 24 / 610 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 7" x 12" / 178x305 |
| Tractive Effort (lbs / kg) | 3332 / 1511.37 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 6.05 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 3.50 / 1.07 |
| Firebox Area (sq ft / m2) | |
| Grate Area (sq ft / m2) | |
| Evaporative Heating Surface (sq ft / m2) | |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | |
| Evaporative Heating Surface/Cylinder Volume | |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | |
| Same as above plus superheater percentage | |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |
