New Bridgewater Bridge

The River Derwent crossing at Bridgewater has a long history, dating back to 1830 when convicts started construction on the causeway. A punt was then used to complete the crossing from the end of the causeway to the northern bank of the River until the first bridge structure was completed in 1848.

The existing lift span road and rail bridge was opened in 1946 and is the fourth bridge to be built at this location.

The existing bridge no longer meets contemporary design or loading standards and constrains productivity on the heavy vehicle network. The age of the vertical lift span makes its operation unreliable and expensive to maintain.

Building a new Bridgewater Bridge is another chapter in the evolution of the crossing at this location.

Planning for a new Bridgewater Bridge has been ongoing for a number of years, and a set of high-level design requirements for a new bridge were last considered in 2011/12 as part of a planning study done on behalf of the former Department of Infrastructure, Energy and Resources,

The Tasmanian Government has now confirmed the eight design requirements for the new bridge, which are broadly consistent with those determined previously.

The design requirements are:

1. The project will provide a new river crossing between the Brooker Highway and Midland Highway, including connections to the Lyell Highway.
2. The new bridge will have a minimum design speed of 80km/h.
3. The new bridge will include two lanes in each direction.
4. The project will include the grade separation of the Lyell Highway Junction at Granton and Black Snake Road at Granton.
5. The new bridge will have a minimum airdraft clearance consistent with the navigable clearance under the Bowen Bridge.
6. The new bridge will include a shared path for pedestrians and cyclists.
7. The new bridge will include safety screens and barriers.
8. The new bridge will not preclude the future use of the existing rail corridor.

Key design requirements for the new Bridgewater Bridge.

A range of possible bridge designs are capable of meeting these requirements within the allocated project budget, and two high-level concept designs have been released.

Option 1

The first option would see a new two-lane bridge built, and the replacement of the existing bridge with a new bridge, providing two lanes in each direction.

Option 2

The second option would see a new four-lane bridge built, with two lanes in each direction.

Work on the project is progressing. Geotechnical, heritage and environmental investigations of the area around the bridge started in January 2020 and are ongoing. These will need to be completed before an Environmental Impact Statement and design can be finalised. The planning and environmental assessment and approvals process will start later this year.

An Early Contractor Involvement (ECI) procurement process will start at the end of August, with a Request for Proposal released to market.

The RFP process is a major step forward and will see two contractors selected to enter a competitive design and tender process to determine a final design for the new bridge that will achieve the best value for the Tasmanian community.

Involving contractors in the project design is an innovative way of doing business that allows for closer involvement in the development of the designs, providing an opportunity for industry innovation and construction.

A Design and Construct contract is due to be awarded in late 2021, with construction to start in 2022. We are working to have people driving on the new bridge by the end of 2024.

Geotechnical, heritage and environmental investigations to inform further development of the final bridge design started in January 2020 and are ongoing.

These investigations include analysis of the ground conditions approaching the proposed new bridge location, depth and quality of bedrock under the river, the mapping of rock faults and the properties of river sediments. This will help determine the final design for the bridge foundations.

The Department of State Growth has commissioned comprehensive environmental, Aboriginal and historic cultural heritage investigations to ensure that all values in the development zone are considered throughout the design and development phases of the project.

These investigations commenced earlier this year and are ongoing, including regular bird life surveys.

During these investigations, there will continue to be people working near the existing Bridgewater Bridge, including around the causeway and bridge, around adjacent properties and in the River Derwent.

There may be traffic management where work is taking place close to the road. Changed traffic conditions and warning signage will alert road users when works are underway.

Road users are asked to approach the area with caution, and follow the directions of traffic controllers and signage.

How much will it cost to build a new bridge?

The Australian and Tasmanian Governments have committed $576 million for a new Bridgewater Bridge. This is the largest ever investment in a single transport infrastructure project in Tasmania’s history.

Why don’t the options include rail?

It isn’t possible to include rail on the new bridge within the available funding. The concept designs for the new bridge don’t preclude the future use of the existing rail corridor.

Will there be pedestrian and cycling facilities?

Yes, pedestrian and cycling facilities have been given a high priority and are addressed in the design requirements.

What is the procurement process?

The Tasmanian Government has elected to use a two-stage Early Contractor Involvement (ECI) procurement process.  At the end of the first stage, two tenderers will be selected to enter a competitive design process to achieve the best value for money design that meets the design requirements and technical specifications. The successful tenderer will be awarded a fixed sum Design and Construct contract.

When will a design be finalised?

A reference design for the new bridge will be finalised in the second half of 2020. This design will be provided to the shortlisted contractors as part of the Early Contractor Involvement process.

When will construction start?

Early preparation works such as demolitions and service relocation will start prior to a contract being awarded at the end of 2021. Construction of the new bridge is due to start in 2022.

When will a new bridge be finished?

We are working to have people driving on the new bridge by the end of 2024.