Bridge an old, stable mate

BRIDGEWATER Bridge has been enshrined with a heritage marker to commemorate the landmark structure long after the traffic has gone.

Engineers Australia presented the bridge’s National Heritage Marker and information plaques at a ceremony on Wednesday attended by Tasmanian Governor Kate Warner.

The plaques will be displayed at both ends of the bridge and will explain the history of the river crossing.

Engineers Australia Tasmania general manager Vicki Gardiner said in early Van Diemens Land the only way to cross the River Derwent was by ferry, which was both costly and dangerous.

“Construction of the cause- way, using convict labour, was the first part of the solution,” Dr Gardiner said.

“Four bridges were eventually constructed over the Derwent, between the causeway and the northern bank, the fourth, the all-steel truss and lift span structure was completed in 1946 and is still operating after more than 70 years’ service.”

The first bridge, completed in 1849, was designed and constructed by convicts Alexander Thomson and James Blackburn with the current structure designed by Sir Allan Knight.

Pitt and Sherry senior engineer Andrew Fowler, who was involved on refurbishment works on the bridge from 2007-12, said it was the second largest lift span bridge that ever existed in Australia after Hobart’s floating bridge.

“It’s a very good demonstration of an early welded structure,” he said.

“It’s lasted 75 years so far and has served us well, it’s been able to cope even as truck masses and traffic loads have increased.”

It is set to be replaced by a four-lane, $576 million state-ofthe-art bridge that includes safe pedestrian and cyclist access. Peak construction is expected to occur between 2022 and 2024.

A Department of State Growth spokeswoman said the existing bridge would be retained but its future transport use was yet to be determined.

She said the business case for the new bridge was currently being assessed by both Infrastructure Australia and the Federal Department of Infrastructure, Regional Development and Cities.