Crack found in new $786m Bridgewater Bridge, RTI documents reveal
The bridge was funded by the state and federal governments. (Supplied: Department of State Growth)
In short
A "non-minor defect" in the form of a "large crack" was found on one of the piers of the new Bridgewater Bridge, days before its official opening, right to information documents show.
The defect prompted a redesign and strengthening works over the following months, which the government described as "minor adjustments to meet long-term performance standards".
The Department of State Growth has told the ABC the bridge was certified as safe before opening to traffic and that the cracking never posed a risk to the public.
Just days before the opening of the new Bridgewater Bridge — spruiked as Tasmania's largest-ever infrastructure project — a "large crack" was discovered in one of its supports.
This led to extra work, some of which was required before the bridge formally opened, documents released under Right to Information (RTI) laws show.
The $786 million bridge, funded by the Tasmanian and federal governments, is part of the Midland Highway and spans the River Derwent — replacing the decommissioned old bridge.
Cracking was found in one of the piers of the bridge. (Supplied)
The crack in the plinth, or concrete pedestal, at the top of pier 1 of the bridge was described as a "non-minor defect".
The department said "non-minor defect" was a "contractual term" and that it did not pose any risk to road users, stating "the bridge is already safe".
The plinth connects to the "shear key" above it, which supports the deck of the bridge and helps keep any movement of the bridge, such as by thermal expansion, under control.
The issue was reported by the project's independent verifier during inspections on May 27 last year.
It prompted strengthening work at five locations along the 1.28-kilometre-long bridge ahead of its June 1 opening, some of which were deemed necessary for the verifier's Opening Completion Certification.
The Bridgewater Bridge opened to traffic in June 2025. (ABC News: Ebony ten Broeke)
A need for additional strengthening work to ensure resilience in "extreme loading cases" such as earthquakes, floods, or ship impacts was also identified as a result of the investigation into the cracking, which the department's project director suggested was necessary to comply with contract requirements.
According to a department report, the shear key of that particular pier was designed to prevent movement in all horizontal directions, but load capacity had been miscalculated during the bridge's design phase.
The piers hold up the bridge. (ABC News: Simon Farrell)
Load capacities miscalculated
In June 2025 — the first month of the bridge being open to traffic — McConnell Dowell (MCD), the company contracted to design and construct it, investigated what had caused the crack at Pier 1.
The documents show that the modelling of the two southern piers' load capacities was inaccurate because southern land reclamation was not considered.
A department summary of the issue stated that revised calculations found the loads on the two piers were "significantly higher (up to 100 per cent higher)" than initially thought.
"It appeared that the shear load at P1L exceeded the SLS [Service Limit State] of the plinth, resulting in cracking of the plinth and grout,"it said.
The Service Limit State ensures that a structure remains functional and durable under normal operating conditions.
The bridge forms part of the Midland Highway, which runs between Hobart in the south and Launceston in the north. (ABC News: Ebony ten Broeke)
The documents show that MCD proposed new strengthened designs, which were approved in principle in October.
The ABC asked MCD a series of questions about the issue, but the company declined to comment.
In a statement, the Department of State Growth said "rectification" and "strengthening" works to pier 1 had been completed.
"The New Bridgewater Bridge was certified as safe for use prior to its opening on 1 June 2025, and at no point did the cracking identified at pier 1 pose any risk to road users or the general public," a spokesperson said.
"Modern bridges are designed to flex and move, and the shear key continued to perform as intended under normal operating conditions.
"Precautionary strengthening was done to account for the stiffness of the reclaimed land at the southern end of the bridge. Updated modelling showed higher-than-expected forces on the plinth, which likely caused the cracking.
"After the bridge opened, further analysis identified the need for additional strengthening to ensure long-term resilience in extreme events such as major earthquakes or ship impacts. This work was unrelated to the operational safety of the bridge, which has always been assured."
The bridge cost $786 million. (ABC News: Simon Farrell)
It is not the first issue with the bridge to need rectification.
Earlier in the bridge's construction, in October 2024, work was undertaken to fix a problem with the alignment of sections of the bridge.
In October 2024, sections of the bridge were out of alignment, prior to the opening to the public. (ABC News: Jonny McNee)
Calls for transparency
The Tasmanian Greens say they were contacted with concerns about the Bridgewater Bridge, and asked the government last year about it.
Greens leader Rosalie Woodruff said the state government must be open about any issues with large infrastructure projects.
"There may or may not be problems, but there is a requirement for full transparency from the government here, they need to be very, very clear with Tasmanians," Dr Woodruff said.
The ABC also asked the government about any structural issues with the Bridgewater Bridge in September 2025, and was told there were none.
After receiving more information from the public, The ABC submitted a Right to Information request, which yielded documents about the crack.
The State Growth Department maintains there were no structural issues with the bridge, but "minor adjustments" were needed for its longevity.