When it opened on 29 March 1965,[1] the Tasman was the longest prestressed concrete bridge in Australia,[3] with a total length measuring 1,396 metres (4,580 ft), including approaches.
[6] It caused two piers and three sections of concrete decking totalling 127 metres (417 ft), to collapse and sink the vessel, resulting in the loss of twelve lives.
The disaster split the city in half, forcing commuters living on the eastern shore to make a 50-kilometre (31 mi) round trip to the CBD via the next bridge to the north.
[3] By 1957, the airport was the country's fifth busiest,[13][14] and the surge in air travel, associated automobile usage and surrounding developments led to a notable rise in traffic, overwhelming the capacity of the existing Hobart Bridge.
These challenges highlighted the pressing need for a new, more accommodating bridge designed specifically for the increased traffic flow without constant interruptions for maritime navigation.
The stable foundation for the bridge was ensured by the favorable conditions of the riverbed between Queens Domain and Montagu Bay on the eastern shore, which includes bedrock, dolerite, and basalt beneath the silt.
[15] Criticism of then-Premier Eric Reece arose in 1958 when concerns were raised by engineers about the susceptibility of the concrete design to potential ship collisions.
Investigative reports revealed Reece's dismissal of objections during parliamentary proceedings in favor of the $14 million project over a slightly more expensive suspension bridge option.
[4] On 5 January 1975, the SS Lake Illawarra, a 140-metre (460 ft) bulk ore carrier, collided bow first with the pile capping of Pier 19 and then amidships with Pier 18[22] while en route to EZ Industries' Risdon Zinc Works with a cargo of 10,000 tonnes (9,800 long tons; 11,000 short tons) of zinc concentrate.
[6] These successive impacts led to the collapse of both piers, their supporting pylons, and three unsupported sections of the bridge deck spanning 127 metres (417 ft), causing the vessel to sink and resulting in the deaths of seven crew members.
[26] He had introduced the locally-built ferries Matthew Brady and James McCabe to the river crossing, from the Hobart city centre to the eastern shore, shortly before the collision.
Reece argued that the selected design was the sole financially viable option for the state at that time, despite the construction costs doubling throughout the project's execution.
[6][31][32] The average depth of the river between piers 17 and 19 is 35 metres (115 ft), with the wreck of the SS Lake Illawarra lying on the bottom covered by a scattering of concrete debris, presenting no navigational hazard to smaller watercraft.
[33] In 2022, the CSIRO and Jacobs Engineering Group collaborated to produce the first complete 3D model of the wreck, bridge, riverbed, and shoreline.
[37] These remotely programmable lights have been utilized for various purposes, including commemorating annual events such as Dark Mofo and the TasPride parade, supporting sports teams like the Hobart Hurricanes and Tasmania JackJumpers, marking special occasions like the inauguration of Queen Mary of Denmark, and raising awareness for causes such as Women's Health Week and Men's Health Week.
In 1987, a renovation initiative implemented the use of sensors to measure the currents of the river and the strength of winds, assisting ships in determining the optimal route for safe passage beneath the bridge.