||Technology in Australia 1788-1988
Table of Contents
I The First 100 Years 1788-1888
i Location of the Railway
iii Bridging and Tunnelling
iv Dams for Engine Water
v Locomotives and Rolling Stock
vi Signalling and Telecommunications
vii 1900/1988-The New Century
viii The Garratt Locomotive
ix Steam Locomotive Practice
x Motor Railcars
xii Electric Tramways
xiii Electric Railways - Direct Current
xiv Electric Railways - 25 kV ac
xv Diesel Traction
xvi Alignment and Track
III Motorised Vehicles
V Modern Shipping
VI Innovative Small Craft
The Garratt LocomotiveIn a quest for more power -usually pulling power or tractive effort rather than horsepower -from a single locomotive over indifferent track, overseas railway engineers had by 1900 already developed a variety of articulated multi 'engine' locomotives drawing steam from one boiler. The British Fairlie, continental Meyer, and continental/U.S. Mallet were the most common. In 1907 Herbert Garratt, the N.S.W. Railways' Inspecting Engineer in London, proposed a new form of 3 piece articulated locomotive.
It had a central frame, a conventional boiler and a single cab slung between two end 'engine' units, each with one set of cylinders, wheels and motion; both engine units had water tanks and that adjoining the cab, a fuel bunker as well.
Garratt was an Australian and it would be nice to claim that he fully recognised the major breakthrough in steam locomotive technology that his arrangement permitted, but it seems that he did not. The big advantage of the Garratt is that it permits use of a boiler dimensioned up to the full cross section of the loading gauge, with a firebox and grate unconstrained by wheels. The engine units were fully able to exploit this boiler with the locomotive weight spread over a long, flexible, multi axle wheel base. This made possible a powerful, high tractive effort, good riding locomotive eminently suitable for Australia's light track and weak bridges, but these features were not exploited in Garratt's first engine. It was a very small narrow gauge engine on two 2 axle bogies, with its cylinders inboard and arrange for compound expansion according to the prevailing fashion of the time. It was built for the 600 mm gauge Dundas Tramway in N.E. Tasmania in 1909 and, after long service and several changes of hands, is preserved in the Railway Museum at York, England.
The Garratt concept was taken up, developed and aggressively marketed not by Australia, but by Beyer Peacock, the famous British locomotive building firm. Early Australian applications were in Tasmania (including 8-cylinder double Atlantic (4-4-2+2-4-4) express engines) and in W.A. both on 1067 mm gauge and before the First World War, and later in Victoria, Queensland, S.A. and finally N.S.W. The concept was sold to railways on every continent except North America and reached its fullest potential in Africa with very powerful and fast (2500 kW at 130 km/h) double Pacifics (4-6-2+2-6-4) in Algeria, and double Northerns (4-8-4+4-8-4) in East Africa and N.S.W. for freight service.
Organisations in Australian Science at Work - N.S.W. Railways
People in Bright Sparcs - Garratt, Herbert; Macfarlane, Ian B.; Smith, A. E.
© 1988 Print Edition pages 467 - 468, Online Edition 2000
Published by Australian Science and Technology Heritage Centre, using the Web Academic Resource Publisher