||Technology in Australia 1788-1988
Table of Contents
I Construction During The Settlement Years
II The Use Of Timber As A Structural Material
III Structural Steel
IV Concrete Technology
VI Industrialised Pre-cast Concrete Housing
VII Ports And Harbours
IX Heavy Foundations
XII Water Engineering
XIV Major Buildings
XVI Thermal Power Stations
XVII Materials Handling
XVIII Oil Industry
XIX The Snowy Mountains Scheme
XX The Sydney Opera House
XXI The Sydney Harbour Bridge
XXII Hamersley Iron
XXIII North West Shelf
Sources and References
The story of bridge engineering in Australia is a fascinating one which begins with the needs of the first settlers in the infant colony and continues today with some of the most dramatic and advanced bridges in the world. Separating these two eras is the story of bridge development in this country -a story truly entwined with the history of the nation itself. For when the bridge builders were inhibited by the large rivers, gorges and estuaries, the expansion of the European settlement was contained and development was slow. But as soon as bridge technology enabled longer gaps to be crossed, the pace of expansion quickened and roads and railways grew outward apace to open up and develop more of this huge country.
The approach to the design of a bridge is intimately tied to the environment and is dictated by the circumstances under which the bridge is to be constructed or to function. Each site is topographically different and the availability of materials and labour varies. Hence each bridge is unique, requires a unique solution, and an original approach from the designer.
The demands which Australia has placed upon its bridge builders are mixed. The early settlements were isolated communities on the flat coastal plain of a relatively flat continent, and neither community requirements nor extreme topography challenged bridge builders to extend existing technology, such as was exerted on the great suspension bridge builders in America. But the settlements were, on the other hand, literally at the end of the earth, being separated by enormous distances and time from Europe, which was the source of new design and development in bridges. In addition the modern materials of the time, such as cast iron, had to be transported vast distances to this country and hence Australian bridge builders needed to rely on their own resourcefulness, bred of isolation, distance and a unique environment.
One manifestation of this unique environment is the behaviour of the rivers in Australia, which is unlike anything experienced in Europe or, indeed, in most other countries of the world. These rivers, like the climate itself, reflect harsh extremes, so that a river channel may be dry for many months of the year, but in flood may carry more water than the Nile in flood (to quote the example of the Ord River). With no records of floods to guide them, the early settlers had to grapple with this strange phenomenon, and even today, when dry river beds can be driven across for much of the year the economic cost of a community isolated by flood waters is a factor against which the provision of a flood-proof and expensive bridge has to be equated.
In solving these problems, Australia has embraced the innovations produced by others and adapted them successfully to the unique situations presented. We have examples of some very fine 19th century bridge engineering provided for the railway expansion, conceived mainly by British engineers working in the then isolation of the Australian hinterland, and we have well developed examples of many of the newer European techniques such as cable-stayed bridges.
The development of bridge technology in Australia began with the rudimentary road systems which were established in the infant European settlements to enable movement around the settlements and, later, the hinterland. Initially the settlements were confined to small coastal or riverine locations and relied heavily on water transport for supplies and communication. As the settlements became more established it was necessary to move further afield to establish farms, gather raw materials and so on. In the early years bridge technology was limited very much to the 18th century European technology of masonry arches and cast iron, the latter still in its infancy and not produced to any great extent in Australia. The demand was for cheap, rapid construction, using readily accessible materials and utilising the abundant availability of convict labour. This, of course, led to simple tree trunk bridges but, as the Colony gained stability, the government looked towards more permanent structures and, as the skills for quarrying and stone dressing became available, masonry bridges began to be designed and built. As all metal materials had to be imported, iron bridges were rarely appropriate and were in any case still too novel for colonial application.
People in Bright Sparcs - Laurie, J. B.
© 1988 Print Edition pages 354 - 355, Online Edition 2000
Published by Australian Science and Technology Heritage Centre, using the Web Academic Resource Publisher