Aecom joint venture to provide detailed design for Sydney harbour tunnel

The contract was awarded by Acciona Construction Australia, which is delivering stage two of Sydney’s third harbour crossing.

Following the acceptance of an alternative client reference design, the Aecom joint venture will deliver a detailed design of the Western Harbour Tunnel that avoids dredging by using TBMs instead of an immersed tube tunnel.

“The improved design and construction method is an excellent example of industry collaboration and is expected to deliver significant reductions to the amount of steel and concrete required, as well as other environmental benefits, compared to the original reference design,” said Richard Barrett, chief executive of Aecom’s Australia and New Zealand region.

The A$4.24bn (US$2.89bn/£2.36bn) Western Harbour Tunnel will provide a western bypass of the CBD, and take pressure off the Sydney Harbour Bridge and Tunnel, and Anzac Bridge. It will connect to WestConnex at the Rozelle Interchange, cross underneath Sydney Harbour between Birchgrove and Waverton, and connect with the Warringah Freeway near North Sydney via a 6.5km with three lanes in each direction.

Construction of stage one is under way, with a John Holland and CPB joint venture building the 1.7km of tunnels from Rozelle to Birchgrove.