Bridge builders

Convict era Causeway

John Lee Archer

John Lee Archer was the Civil Engineer and Colonial Architect of the colony of Van Diemen’s Land (Tasmania) from 1827 until 1838. Originally trained in London, Archer was appointed to the position of Civil Engineer after arriving in the colony. Soon after he was also given the duties of Colonial Architect, ultimately responsible for all the construction of all the colony’s government and public buildings.

While initially tasked mostly with prisons and other convict related structures, the growing number of free settlers meant that Archer also designed a number of Tasmania’s famous Georgian-style public buildings, including several famous churches and chapels, and the Parliament House in Hobart, as well as numerous military and civil buildings around the colony.

John Lee Archer helped to design and repair several bridges, including Ross Bridge, Richmond Bridge, and the Hobart Rivulet Bridge, as well as providing designs for the still-unfinished Bridgewater causeway in 1835 as part of a committee.

He was the architect for the Theatre Royal (Australia's oldest continually operating theatre), Cape Bruny Lighthouse (Australia's second oldest extant lighthouse), Willow Court in New Norfolk, the Female Factory, many buildings in Anglesea Barracks and the Hobart and Richmond gaols.

Roderic O'Connor

Roderic O’Connor was an Irish landowner who emigrated to Van Diemen’s Land (Tasmania) in 1824 along with his two sons Will and Arthur. O’Connor quickly set to work on his initial land grant of 1000-acres along the Lake River, working to renovate and improve the property with several new buildings, bridges and wiers.

O’Connor’s engineering skills were quickly noticed by Lieutenant-Governor George Arthur, who chose him to be one of the Commissioners of Survey and Valuation of the colony, tasked with helping to divide Tasmania into various counties and parishes, and to accurately calculate rent owed to the Government and the Crown.

Once his tenure as Commissioner was over, O’Connor was appointed to the position of Inspector of Roads and Bridges, giving him responsibility over a huge stream of convict labour for the purpose of erecting public works and infrastructure. One of the largest of these convict works was the Bridgewater causeway. Close to the causeway’s completion in 1836, he would submit a report that listed the potential options for crossing from the end of the causeway to the opposite side of the river, including a punt (a small platform that was winched across the gap by cables), a floating pontoon bridge, or a suspension bridge. While the punt was chosen at this time, a bridge was soon to replace it.

References:

• Ian D. Cooper, 2018. ‘Bridgewater Bridge Tasmania: Nomination for Engineers Australia Engineering Heritage Recognition.’ Prepared for Department and Infrastructure Tasmania and Engineering Heritage Tasmania. P.7
• ‘John Lee Archer (1781-1852) Oxford Reference.
• ‘John Lee Archer (1791–1852)’, Australian Dictionary of Biography.
• P. R. Eldershaw Eldershaw, 2006. ‘Roderic O’Connor (1784-1860)’, Australian Dictionary of Biography.
• Ian D. Cooper, 2018. ‘Bridgewater Bridge Tasmania: Nomination for Engineers Australia Engineering Heritage Recognition.’ Prepared for Department and Infrastructure Tasmania and Engineering Heritage Tasmania, p.2

Bridge No. 1 (1849 - 1899)

James Blackburn and James Alexander Thompson

James Blackburn and James Alexander Thompson were two former convicts who designed and built the first form of the Bridgewater Bridge in 1849.

Blackburn had been transported to Van Diemen’s Land (Tasmania) in 1833 for forging a cheque and was placed in the employment of the Department of Roads and Bridges working under Roderic O’Connor.

Thompson had been convicted and transported in 1825 and worked as a draftsman.

After the two completed their sentences, around c.1840, they came together to form a private architectural practice, designing and constructing several buildings, bridges and churches throughout the colony including the first Bridgewater Bridge, the contract for which was awarded to the pair in 1846.

This first iteration of the bridge was designed with a timber truss rolling span that moved along iron wheels and rails controlled by hand winches, allowing the bridge to twist and open 11m for ships and vessels to travel through.

The centre of the swing-bridge was supported by a four-columned tower with chains suspending either end of the rolling section.

By 1880 this bridge was still in operation, acting as the only traversable road passage across the river. However, in 1888 it was deemed to be unsafe due to deterioration and was eventually demolished in 1899.

References:

• Ian D. Cooper, 2018. ‘Bridgewater Bridge Tasmania: Nomination for Engineers Australia Engineering Heritage Recognition.’ Prepared for Department and Infrastructure Tasmania and Engineering Heritage Tasmania, p. 6 Ibid.
• Ian D. Cooper, 2018. ‘Bridgewater Bridge Tasmania: Nomination for Engineers Australia Engineering Heritage

Bridge No. 2 (1874)

A new, second bridge was constructed by the Tasmanian Main Line Railway Company (TMLR), a privately owned business that was formed in 1872.

With the introduction of trains into Tasmania in the early 1870, railways were often constructed and maintained by these private companies.

The TMLR had been founded for the purpose of providing travel between Hobart in the South and Launceston in the north, with the Bridgewater causeway chosen as the point of crossing for the train line.

This bridge was constructed  in 1874, with the causeway being widened to fit the new railway track that would run along it.

This new bridge jutted off the east at the end of the causeway, reaching the northern bank roughly 15 metres from the earlier 1849 bridge, which still continued to provide a crossing by road.

References:

• https://libraries.tas.gov.au/slat/guides-to-records/tasmanian-railways/agencies-responsible/ River Derwent, Tasmania – Bridgewater Bridges – Past and Present, P. 3-4

Bridge No. 3 (1892) - John Wishart Snr

John Wishart Snr was born in the Orkney Islands, United Kingdom in 1835, and moved to the Victorian goldfields at age 20.

After moving around Australia, Wishart Snr created a contracting business responsible for a variety of large projects in South Australia, including the Inter-colonial Railway from Mount Loft to Nairne and Railway Bridges in Adelaide, as well as several other projects in Victoria and New South Wales.

Wishart Snr’s company, Wishart and Son, was awarded the contract for the proposed swing bridge over the Derwent at Bridgewater in 1892 (completed by 1893).

This bridge was created in order to replace the earlier 1849 bridge, the only road link across the Derwent in this area, but by 1888 was in a deteriorated state and deemed unsafe.

The new bridge was unique in that it extended directly out from the causeway, where the previous road bridge curved eastward out towards the downstream bank of the river.

References:

• Ian Cooper 2018– p.7
• River Derwent, Tasmania – Bridgewater Bridges – Past and Present, P. 4.

Bridge No. 4

Sir Allan Walton Knight

Allan Walton Knight was the first Bridgewater Bridge builder from Tasmania, born in Launceston in 1910.

Knight graduated from the University of Tasmania with a degree in Science and Engineering, and later went on to join the Public Works Department (PWD) in 1932, achieving the position of Chief Engineer by 1937.

After travelling to America in 1937 to observe and investigate their lift span bridge technologies, he returned to Tasmania to develop designs for two new bridges along the Derwent, including the Hobart Floating Bridge (1938-1943) and the new lift span Bridgewater Bridge, which commenced construction in 1938.

After this fourth bridge was complete, Knight went on to become the Commissioner for the Tasmanian Hydro Electric Commission in 1946, winning international recognition for new advances in dam and power station technology and engineering. Knight was awarded several awards and honours throughout his career and would eventually be knighted in 1970.

David Victor Isaacs

David Victor Isaacs was born in Melbourne in 1904, graduating from the University of Melbourne with a degree in Engineering and later a Masters in Civil Engineering.

Isaacs would go on to become one of the most respected civil engineers in the country, and one of the Founding Directors of the Commonwealth Experimental Building Station (1944-69).

Isaacs would be hired by the Tasmanian Public Works Department to work on designing the new, electric-welded Bridgewater Bridge, alongside Chief Engineer Allan Knight.

References:

• Ian Cooper, p.24