Western Harbour Tunnel: Sydney’s third harbour crossing gets tick of approval, change of construction tactics

Major changes to the Western Harbour Tunnel have been greenlit by the NSW Government, as a shock western Sydney suburb is set to bear the brunt of construction work more than 50kms away.

A major change in tactic for constructing the Western Harbour Tunnel has been greenlit by the state government.

NSW Planning approved the use of state-of-the-art Tunnel Boring Machines (TBMs) to dig Sydney’s third harbour crossing, while the western Sydney suburb of Emu Plains is set to be the staging ground for construction of the pre-fabricated tunnel.

The Western Harbour Tunnel will use state-of-the-art Tunnel Boring Machines have been approved increase efficiency and reduce negative impacts of the Western Harbour Tunnel.

“The use of TBMs is a positive change which will help minimise environmental and community impacts and maximise construction efficiency,” a Transport for NSW spokesperson said on Wednesday.

“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 spokesperson said the TBMs will be used to create “twin” 1.5km sections of tunnel under the Sydney Harbour, reducing the number of construction sites needed and minimising the impact on the harbour.

A Tunnel Boring Machine (TBM) such as this will be used to drill the Western Harbour Tunnel through the seabed of Sydney Harbour.

“It will also allow us to start work to deliver Berrys Bay parkland earlier, pending further consultation with the community and relevant approvals,” they said.

“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.”

The spokesperson confirmed that a “new construction support site” would be established at Emu Plains, some 50km away in western Sydney, to build concrete segments for the tunnel lining.

Artists Impression of the changes to the way the community moves between western and northern Sydney once the Western Harbour Tunnel and Beaches Link is completed. Picture: Supplied.

Transport documents reveal a purpose-built “precast facility” would be constructed in Emu Plains to manufacture concrete segments that fit together to line the TBM digging the 6.5km stretch in an effort to “reduce impact for local residents” in the city’s east.

Original plans would have seen a construction support site for the tunnels on Glebe Island in Sydney Harbour, however, Transport representative said “Glebe island does not have the capacity to include the manufacturing of the tunnel components required for the Tunnel Boring Machine”.

“We have identified a new location for this construction support site at Railway Street in Emu Plains, on a portion of land that has operated as a quarry since the 1960’s,” notification to residents said.

“This site was chosen due to it being an existing industrial area that provided the amount of space and operational capacity needed to manufacture and store the precast concrete segments to line our tunnel walls.

“The location also provides more direct access to the project’s other construction support sites.”

In the latest statement regarding the construction method change, the Transport for NSW spokesperson said making the precast tunnel segments in Emu Plains would “create job opportunities for the community and the surrounding Penrith LGA”.