While building a new Bridgewater Bridge has been talked about for more than two decades, it is now becoming a reality, with the awarding of a contract for the design and construction of the project to McConnell Dowell. Work is now underway in preparation for construction to start later this year on what will be the biggest transport infrastructure project in Tasmania’s history.
Described as a once-in-a-generation project, the anticipation around the construction of a new Bridgewater Bridge, around 20km north of Hobart, is growing.
The project itself isn’t a new concept. It’s been talked about for more than 20 years, and locals know better than anyone the variety of different plans and designs that have been developed over that period.
Work on the $786 million Australian and Tasmanian government project has ramped up over the past two years, with the project now gearing up to break ground later this year.
Forming a critical part of Tasmania’s transport network, the Bridgewater Bridge is a key link in the Burnie to Hobart freight corridor, Tasmania’s highest volume freight network.
It also acts as an important transport connection for greater Hobart, facilitating access between central Hobart and growing communities at Bridgewater and Brighton, as well as between the Brighton Transport Hub and major industrial and freight distribution centres in Glenorchy.
New Bridgewater Bridge Project Director, Ben Moloney, said upgrading the important corridor will benefit the 22,000 people that travel across the bridge and on surrounding roads each day.
“Removing the bottlenecks currently experienced at each end of the bridge will reduce congestion, but it will mean people can more reliably plan their journeys with consistent travel times,” Mr Moloney said.
“On top of that, a free-flowing crossing with a higher speed limit will improve freight routes and improve productivity for the heavy vehicle industry.”
Developing designs and tenders
While the need for a new bridge is obvious, what may be a lesser-known fact is that the new bridge will be the fifth built across the River Derwent at this location.
Completed in 1946, the current steel truss vertical lift bridge is reaching the end of its useable life, and with an unreliable lifting span, the structure is expensive to maintain.
The bridge and causeway no longer meet contemporary design requirements, and despite connecting to the National Land Transport Network at either end, the bridge provides just a single lane of traffic in each direction and a 60km/h speed limit.
Projects of this size and scale don’t come around often in Tasmania. To allow input and expert advice from the construction industry, the Tasmanian Government chose to utilise a competitive Early Contractor Involvement (ECI) procurement process to deliver the project.
Mr Moloney said CPB Contractors and McConnell Dowell were shortlisted following an extensive Request for Proposal process and spent 2021 working collaboratively with the government to develop their designs and tenders.
“The ECI process allowed us to look more broadly at the industry and utilise experienced road and bridge builders to showcase their practical knowledge and expertise to develop designs and construction methods best suited to the Tasmanian market,” Mr Moloney said.
“What we want to be able to do is achieve the best whole-oflife value for money project that delivers ongoing benefits to Tasmanians, and I think we will be able to do that”.
McConnell’s chosen design will see the construction of a new 1.2km precast concrete box girder bridge built downstream of the existing Bridgewater Bridge. The four-lane structure will include a three-metre-wide shared path for cyclists and pedestrians and a navigation clearance matching the Bowen Bridge some 15km downstream.
Construction will be via a temporary bridge structure and interlinked barge pontoons and will also include precast concrete production and batching plants.
At Granton, the Lyell Highway junction and Black Snake Road junction will be grade separated from the Brooker Highway, allowing for free-flowing traffic from the Brooker Highway onto the Lyell Highway towards New Norfolk.
One the northern side of the river at Bridgewater, the chosen design includes new Midland Highway ramps at Old Main Road, and the connection of Gunn Street and Old Main Road under the new bridge.
Stakeholder engagement and job opportunities
Mr Moloney said feedback from the local community and broader stakeholder groups played a vital role in design development for the bridge and interchanges, with an extensive engagement and consultation process undertaken on a reference design in late 2020.
“We heard loud and clear from the community that they wanted free flowing connections and better access to and from local roads,” Mr Moloney said.
“Based on that feedback, a number of enhancements were incorporated into McConnell Dowell’s design including a south bound on ramp onto the bridge from Bridgewater and better connections between the Brooker Highway and Lyell Highway, allowing for improved travel between Hobart and Derwent Valley.”
Local residents and commuters travelling through the area won’t be the only winners, with major construction to support around 830 direct and indirect jobs.
It is expected that McConnell Dowell will procure around 85 per cent of the construction work through subcontract agreements with Tasmanian companies, who will need to recruit extra capacity into their organisations. This will provide increased job and career opportunities for Tasmanians and potentially increase the long-term skills and capacity of the industry.
Mr Moloney said the flow-on effects to the broader Tasmanian community will be significant, with a range of industries set to reap the benefits of such a major construction project.
“We know we will see an increase in work in the civil construction industry, but there are also exciting opportunities for small businesses as well, from the local café to accommodation in the area,” Mr Moloney said.
“This project will leave a legacy both in the local communities where we will see construction, but also to the broader Tasmanian community.”
Early activities, including detailed design and site investigations, are now underway ahead of major construction starting later this year once necessary approvals are in place.
Construction is expected to take around three years, with the new bridge scheduled to be open to traffic by the end of 2024.