G & C Hoskins 4-6-4 Locomotives in Australia

Class Details by Steve Llanso of Sweat House Media

Class Iron Duke (Locobase 20751)

Data from "Australian Locomotives with American Characteristics", Locomotive Magazine, Volume XXVI [26] (14 August 1920), p. 169. See also "Photograph of 4-6-4 side tank locomotive 'Iron Duke' on the Museum of Applied Arts and Sciences website at []; and "AIS, Locomotive "Iron Duke" tank type, Port Kembla, NSW [c.1930s]", Living Histories @ UON, University of Newcastle, Australia website at []; and Clive Beauchamp, "Disaster at Hoskins' Ironstone Quarry, Cadia, Orange, 1921" Journal of Australasian Mining History, Volume 10 (October 2012), pp. 103-111 at []; all last accessed 19 July 2020. Works number was 242 in 1919.

LM's 1919 report included only the sketchy details shown in the Locobase specfications. Its Belpaire boiler was typical of many Australian locomotives and the engine's overall appearance, said the article, was that of the New South Wales Government's S class (Locobase 2409). Indeed, the heating surface was the same, and likely the firebox and grate areas, but Locobase has been unable to confirm. Clyde shortened the stroke by two inches (50.8 mm) and reduced boiler pressure.

The report misstates the extent of American influence in the design. The bar frame was indeed inspired by American practice and the smokebox saddle was in fact commonly used. US locomotives often had outside bearing boxes on the truck, but the trucks' bulk plate frames shown in the photograph owed much more to British influence as did the cab, the dome, and the chimney (stack).

LM's characterisation of the locomotive's intended service--fast mixed traffic--is puzzling as well as its career consisted of working mineral trains. MAAS's description of the Iron Duke's photograph gives the details of the engine's career. Beginning at the Hoskins Cadia iron ore mine near Orange, NSW, Iron Duke pulled trains of iron ore from the mine to Spring Hill Junction's Exchange Siding. The engine's name most likely derived from a particular seciton of the Cadia Ironstone quarry that opened in 1918.

Hoskins built the 12-mile (19.3 km) connection and also erected workers' cottages near the siding at Spring Hill. Given the distance between the quarry and the junction, the "fast mixed traffic" LM referred to may have been moving the workers to the quarries in the morning and home to Spring Hill at night.

The closing of the branch line in 1928 led Cecil Harold and Arthur Sidney Hoskins to combine with several others (the English company Baldwins Ltd, Dorman Long Ltd, and Howard Smith Ltd) to form the Australian Iron and Steel company based at Port Kembla. Iron Duke then began hauling coal from Wongawilli Colliery to the Cringilla steel works. Living Histories @ UON's photograph description adds "Noted in use on ore haulage from jetty and coke haulage from Wongawilli and later at steelworks coke ovens."

The Iron Duke was withdrawn and scrapped in 1957.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassIron Duke
Locobase ID20751
RailroadG & C Hoskins
Number in Class1
Road Numbers
Number Built1
BuilderClyde Engineering
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)
Engine Weight (lbs / kg)163,520 / 74,172
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)163,520 / 74,172
Tender Water Capacity (gals / ML)1900 / 7.20
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.75 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)55 / 1397
Boiler Pressure (psi / kPa)150 / 10.30
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 24" / 470x610
Tractive Effort (lbs / kg)19,042 / 8637.32
Factor of Adhesion (Weight on Drivers/Tractive Effort)
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)
Evaporative Heating Surface (sq ft / m2)1453 / 134.99
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1453 / 134.99
Evaporative Heating Surface/Cylinder Volume194.60
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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