Post 1788: History of NSW Engineering Development

Early days

For as long as the human species has occupied the continent its presence has modified the land and the environment by its mere presence or by conscious and planned exploitation of resources.

The rapid acceleration of deliberate modification to the environment began in 1788 when European settlement began in Sydney. The need for shelter, fresh water and food meant that forest and scrub were cleared, new plants introduced, and streams modified from their natural state.

For decades expansion of the area available for settlement and therefore deliberate modification was limited by the high broken plateaux which surround the basin within which Sydney was sited. Explorers found a way across these mountains to the west only in 1813 and engineers built a trafficable road along the route only two years later in a remarkably quick time and with a very small team of men.

Routes to the south and north followed, though the road to the settlement at Newcastle was an indirect one, thwarted by the wide and deep valley of the Hawkesbury River. Stream crossings were avoided, but where necessary were by ford, by punt, or in some cases by timber or stone bridges. The stone bridges have proven to be extraordinarily well built with some remaining in service carrying modern highway traffic.

The occupation of New South Wales spread along the coast and communication between the towns was based on shipping rather than overland transport.

Although towns and occupation of the land did expand into the west of the colony, while transport was limited to the walking speed of a man, or the hauling capacity of a bullock, productive use of the land was restricted to high value, non-perishable commodities such as wool.

Table 1. NSW Population 1788 to 1850

Year	1788	1800	1810	1820	1830	1840	1850
Population	859	5,217	10,096	28, 024	44,588	127,466	266,900

1850s Onwards - Introduction of Rail

Railways began to be built in the 1850s and they provided a quantum leap in technology and thereby the capacity to exploit the land. Even the earliest trains hauling a hundred tons at 12 mph (20km/hr) but never resting, could reach distant towns in a day rather than weeks. The cost of transport was reduced by a factor of 20.

With Sydney placed in its isolated basin, the route of the first railways radiating from the capital soon met rugged topography and high-class engineering was required to cross these obstacles. Great iron bridges were needed to get past the encircling Nepean River. The Blue Mountains plateau needed zig-zags, tunnels and high stone arch bridges; the line to the south, destined to reach Melbourne in only 26 years, got through without a zig zag, but included a cutting so deep that it is still a landmark. The line from Sydney to the colony’s second city, Newcastle, was just too difficult at first and had to come a little a later. Even the connection to Sydney’s close neighbour and now industrial hub at Wollongong was not made for nearly forty years after work had first begun on railways.

The building of the railway routes was the work of men and horses. Stone and timber were available in abundance. NSW hardwood timber was particularly well-suited to bridge building. Long span bridges required the use of iron, and later steel, but there was no iron industry in Australia so the material had to be imported at both a high cost and with consequent depletion of the cash circulating in the community. Politicians decried the use of iron and forced engineers to use stone and timber. Spectacular timber bridges were built, with that across the Hunter River at Singleton being remarkable for the technical elegance of its long laminated arch spans, and that at Wagga Wagga for the length and the hundreds of spans which carried the route above the wide floor plain of the Murrumbidgee River. Iron bridges were built where they had to be, though at first fabricated overseas. Local engineering firms capable of fabricating bridges from imported iron did arise though it was not until the early twentieth century that they had capacity to become the regular constructors of steel bridges. The wrought iron tubular girder bridge over the Nepean River at Menangle is particularly remarkable since it was opened in 1862 and is still in service on the main interstate route between Sydney and Melbourne.

Also remarkable is the crossing of the same river, though in its lower reaches named the Hawkesbury River, on the route between Sydney and Newcastle. Deemed too large for any local contractor, international tenders were called and at the time of its opening in 1889 it was perhaps the third largest bridge in the world and certainly had the deepest foundations of any bridge yet constructed anywhere.

20th Century

In the early decades of the twentieth century the once impossible railway along the northern coast of NSW was built. Technology, wealth, and engineering capacity had grown to the stage where the bridging of the numerous wide estuaries of the coastal rivers was possible. The bridges were designed by local engineers, fabricated locally from at least some locally produced steel. The last bridge on the route, the long crossing of the Clarence River at Grafton was made double track for future expansion, double-decked to provide a road above the railway, and included a perhaps unique double-deck bascule opening span to allow shipping to pass. It was designed in Sydney and fabricated at Granville.

The Sydney Harbour Bridge was opened in 1932. While the questions as to where it was designed and by whom are unsettled, English contractors undoubtedly undertook the detailed design and the construction, using a majority of imported steel, though about a quarter of the material used was made in Newcastle. Most of the people who worked on the bridge, engineers and tradesmen, were locally recruited however. Perhaps the pinnacle of local steel bridge engineering was reached in NSW during the years of the Second World War. The 1889 railway bridge across the Hawkesbury had failed and needed to be replaced. Beside it a road bridge was needed to replace the ferry. Both were designed, fabricated and erected by local entities using only Australian steel; the railway bridge by the Railways Department and the road bridge by the Main Roads Board, Clyde Engineering and Balgue Constructions.

In the latter half of the twentieth century the transport balance moved strongly towards roads as well as and in place of railways. High quality roads were built in Sydney and radiating from it. The topography of Sydney, with its many flooded estuaries required an unusually large number of significant bridges for a city of its size. Most noteworthy among many is the Gladesville Bridge across the Parramatta River, the longest concrete arch in the world at the time of its construction. Hundreds of long and high bridges, usually of box girder construction in steel and concrete are provided across streams or valleys which once might have warranted no more than a small timber bridge with long winding approaches.

Table 2. Australia’s Population by Colony in 1884

Colony	Population	Per Cent of Australia's population
NSW	899,203	34.51%
Victoria	935,777	35.91%
Queensland	301,857	11.58%
South Australia	308,947	11.86%
Tasmania	126,665	4.86%
Western Australia	33,546	1.28%
Australia	2,605,725	100.00%