As well as the shortage of labourers, builders, and engineers in the Australian colonies in the 1850s, there was little technical literature to guide the work of building transport systems. The development of the civil engineering profession outlined in Chapter 4 ‘Timber truss technology’ shows the key role of the British Institution of Civil Engineers (ICE) in establishing standards for civil engineering. The ICE’s admission grade of Associate (AMICE) and qualification as a full Member (MICE) were essential professional steps for colonial engineers. With 17 years of experience in Ireland, Central America and in the Colony, 33-year-old William Bennett gained the AMICE in May 1857 while completing railway survey work for Whitton and he was awarded the MICE in 1864.
In 1870, Bennett and his colleague, Gustavus Morell, were founding members of the Engineering Association of NSW which produced a journal from 1885. Bennett was also an early member of the Royal Society of NSW, whose president for his first five years in Sydney was the Colony’s Governor, Sir William Denison. An engineer, Denison spoke on ‘Principles of bridge-building’ in September 1860 and, a year later, Thomas Woore’s ‘On a new mode of constructing timber bridges’ challenged Railways chief engineer John Whitton’s fixation on iron bridges.
The utility of Australian hardwood for the timber truss construction techniques highlighted by Woore in 1861 had already been demonstrated in some dozen road bridges. Details of these first timber truss road bridges, from the Carcoar Bridge completed by William Weaver in 1855 to the bridges designed by William Bennett in 1859-60, are given in Chapter 2 ‘Developing the truss’ and Chapter 3 ‘The designers’.23
Until 1879, few of Bennett’s bridge engineers were already qualified when appointed to his staff. After two years at King’s College London, John McDonald had completed three years articled to Appleby Bros in Greenwich and he was working for that firm when he was recruited to Bennett’s staff in 1879 for construction of the Gladesville Bridge. He gained the MICE on its completion in 1881. William Warren had trained in a London railway company after studying at Dublin’s Royal College of Science for Ireland and in Manchester, before emigrating to join Bennett’s office in 1881. Ernest de Burgh, another early engineering graduate of the Royal College of Science for Ireland (now part of University College Dublin) joined the PWD on migrating to NSW in 1885. The engaging and energetic young engineer joined Bennett’s office in 1887, with Bennett nominating him for the AMICE he gained that year and his MICE, awarded in 1893.
From 1878, aspiring AMICE candidates could take courses at the Working Man’s College in Ultimo, or, from 1883, courses at the University of Sydney’s new engineering school established under William Warren. Percy Allan, who had completed his cadetship under Bennett in 1882, was among the first to take the non-degree course Warren offered, completing it in 1885. Allan was not nominated by Bennett for the AMICE, waiting until 1890 for McDonald’s nomination, with his MICE given in 1901.
Three of Warren’s first graduates, Henry Harvey Dare, John Job Crew Bradfield and James Waller Roberts, all became PWD bridge engineers. Dare was on Bennett’s staff from February 1889, for the last months of Bennett’s life, while Bradfield and Roberts were appointed during John McDonald’s much briefer tenure as chief engineer.
Dare, Roberts and Bradfield were all founding members of the University of Sydney’s vigorous new Engineering Society in 1896 and were regular contributors to its journal.
For colonial engineers, local knowledge and experience was no less important than access to technical advances worldwide. The trial and error process of using native timbers is an important example; another is the much longer, slower and more costly understanding of floods in NSW. At Royal Society meetings in Sydney, the many papers on meteorology and weather observations were always keenly followed but for the engineers, ‘on the ground’ experience was the better teacher. Whether reliable or not, local recollections were the main source of flood data for Bennett – along with the damaged bridges themselves and, across the Colony, damaged bridges were flood markers that reset deck heights for their replacements.
Bennett’s Marsden’s Crossing Bridge over the Wollondilly River at Goulburn was only three years old when it was destroyed by an ‘overwhelming and unprecedented flood’ in autumn 1870 that reached six feet (2 m) above the previous record set in 1852. Bennett observed:
This flood was most violent in the vicinity of Goulburn, and in the rivers flowing to the west from the table-land Goulburn to Cooma, and was followed by others of more or less local violence . . . the latest being most violent in the north.24
No lesson was wasted and when the ‘most violent’ floods in December 1870 turned the Nymboida River into a destructive torrent, Bennett adjusted the plans of the proposed timber truss bridge to raise the deck another six feet. Noting that, in every case, the most serious damage was done ‘by the accumulation of timber against the bridges’, Bennett designed a central iron cylinder pier for the Orara Bridge, located on the same mountainous road from the northern tablelands to the port of Grafton, and for the bridge over Leycester Creek in Lismore (see Figure 1.16). This innovation is discussed further in Chapter 6, ‘The builders’.
Transport infrastructure for railways, roads and bridges, and harbours and rivers, had dominated colonial public works engineering but, with the new century, the emphasis shifted to water resources. The Water Rights Act 1896 (NSW) transferred all use and control of water to the Crown, enabling the new State to develop a systematic public works program. All of Bennett’s best young bridge engineers, now leading their profession, were transferred across to this area: de Burgh in 1903, Allan in 1904 and Harvey Dare in 1910. The pioneer head of the State’s water conservation engineering, LAB Wade, who had been articled to Bennett as a 16-year-old in 1880, had been transferred in 1892 to the new Water Conservation, Irrigation and Drainage section of the PWD. On Wade’s early death in 1915, Dare succeeded him as head of the State’s Water Conservation and Irrigation Commission, serving until his retirement in 1935.