Australia: Tasman Bridge, from the collapse to the reconstruction of a strategic Australian structure

Since 9:27 pm on January 5, 1975, when the Tasman Bridge pylons collapsed, the city of Hobart, the state of Tasmania and Australia as a whole learned to regard this infrastructural work in a different way.

That tragedy which cost the lives of 12 people transformed the bridge that spans over the Derwent river taking travelers from the center of Hobart to the suburbs. Since that day, the Tasman Bridge has become a symbol of infrastructure’s strategic importance and has been the center of several phases of reconstruction and renovation, the last of which was launched in the past few weeks. The Tasmanian transport ministry has announced a AUD130 million investment, the largest since the bridge’s reconstruction in 1975, to increase the structures functionality and safety. The work is also supported by federal funds, aiming to complete the renovation by 2025, when the bridge will again shine on the capital’s bay.

January 5, 1975, was a Sunday, a tranquil day in Hobart and surroundings, and along the Derwent river.  At 9:27 pm the cargo ship Lake Illawarra, transporting 10,000 tons of zinc, chose to cross the bridge beneath a narrow side span instead of the wider central spans. When commander Boleslaw Pelc realized there was not enough room, it was too late. He attempted a drastic maneuver but failed to avoid the collision. The boat crashed against the bridge, causing the collapse of a 127 meters long section. Twelve people died in the disaster, and in addition to these dramatic deaths, the city realized the immediate negative impact on transports. Some 30% of the people living East of the bridge were completely isolated.  From the day after the accident, 30,000 people woke up with enormous problems: the 3 minutes it used to take to cross the bridge were now a 1,5 hours long journey.

Sydney’s Public Transport Commission set up a ferry service to carry people from one bank to the other. A study by the Hobart administration confirmed the significant social impact of the bridge’s collapse. Crime on the East coast rose 41% in six months, car thefts rose 50%, lawsuits jumped 300%. The data, according to the Tasmanian government, showed how strategic the Tasman Bridge was, and convinced the Australian government to set up a commission in 1975 to manage the bridge’s reconstruction.

The first step was the construction of the Balley Bridge, 788 meters long, connecting the two banks of the Derwent river, to give citizens and travelers and alternative to the Tasman Bridge. However, the new bridge, inaugurated just a year after the tragedy, was not sufficient to sustain the region’s transport demand, so the Tasman Bridge Restoration Commission got to work on the reconstruction of the collapsed structure. Expert engineers were charged to design the realization of pylons able to withstand the impact with a large ship without causing serious damage to the bridge. And so, once the most innovative project was chosen, the reconstruction began and was carried out very rapidly. On October 8, 1977, the bridge was reopened to circulation, and in subsequent years more innovative tools were used to safeguard travelers. In 1987 a new renovation led to the use of sensors measuring the river’s currents and the force of the winds to help shipping pick the perfect route to cross safely beneath the bridge. This same bridge is today still the object of upgrades and renovations, confirming the strategic value of such an important public work.

“The Tasman Bridge is an important part of Hobart and a key transport link. It connects the people of Hobart every day and is the gateway to our city for thousands of visitors every year.”

That’s how the Tasmanian transport ministry explained the goal of the AUD130 million in investments earmarked for the bridge’s renovation. The new upgrade involves primarily the pedestrian and bicycle traffic. The project envisages the construction of a new lane, 3,5 meters wide, on both sides of the bridge, dedicated to pedestrians and cyclists. In addition, new barriers will be installed to increase safety, as well as digital systems to manage the entrance and exit of cars to reduce congestion during peak hours.

Work will begin shortly with the aim to conclude the project in 2025, when the Tasman Bridge will show Australian its new look.