A change in construction method has been approved for the Western Harbour Tunnel project in Sydney, with the work to go ahead with state-of-the-art tunnel boring machines (TBMs).
A Transport for NSW spokesperson said that the major change to the proposed construction method involving the use of TBMs has been approved by the Department of Planning, Housing & Infrastructure following public consultation.
“The use of TBMs is a positive change which will help minimise environmental and community impacts and maximise construction efficiency,” the spokesperson said.
“The approval to dig deep under the Sydney Harbour seabed means significant improvements for the environment and local communities compared to the previous plan to sink an immersed tube tunnel on the harbour floor.
“The TBMs will be used to create twin 1.5km sections of tunnel under the Sydney Harbour. This will reduce the number of construction sites needed and minimise impacts on the harbour. It will also allow us to start work to deliver Berrys Bay parkland earlier, pending further consultation with the community and relevant approvals.
The spokesperson said that using TBMs removes the need for dredging in Sydney Harbour, reducing the impact on the marine environment and surrounding communities.
“While the approved change will eliminate the need for cofferdams in the harbour, it will require some changes to the temporary construction site in North Sydney. A new construction support site will be established at Emu Plains to build concrete segments for the tunnel lining.
“Making these segments locally in Emu Plains will create job opportunities for the community and the surrounding Penrith LGA.”
The new site location was selected within an existing industrial space, to minimise impacts on residents and the environment.
Changes to the construction method were put forward in a Modification Report released in July 2023.