Public Works Department 0-4-0 Locomotives in New_Zealand


Class Details by Steve Llanso of Sweat House Media

Class 728 (Locobase 21101)

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 Sweat House Media

Class728
Locobase ID21101
RailroadPublic Works Department
CountryNew Zealand
Whyte0-4-0ST
Number in Class2
Road Numbers728-729
Gauge3'6"
Number Built2
BuilderDavenport
Year1921
Valve GearStephenson
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 wheelbase1
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)20,160 / 9144
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 / 11
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

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