By Lynda Myer
Advancing a bored tunnel beneath Sydney Harbour, was approved by the New South Wales planning authority.
Changing the tunneling method between Birchgrove and Waverton from an immersed tube tunnel to using TBMs, the modification plan of the Western Harbour Tunnel Stage 2 project was confirmed by the New South Wales Department of Planning, Housing and Infrastructure.
Considering that this decision significantly decreased the impact of construction on the community and environment, as Acciona said it marked a significant step forward to build Sydney’s new harbour crossing in a way.
This approval reduces construction impacts by not dredging in Sydney Harbour; reducing the overall number of construction support sites; removing the need for cofferdams in Sydney Harbour at Birchgrove and Balls Head; not impacting Birchgrove Ferry Wharf and ferry services; and reducing impacts to ferries and boats on Sydney Harbour.
The date of commencing excavation process by Acciona on the project was November 2023, by starting up the first of 10 roadheaders on the project to create a temporary access tunnel.
As a project for reducing traffic on the Sydney Harbour Bridge and tunnel, Western Harbour Tunnel is a 6.5km tunnel and connects the Warringah Freeway with the soon to open Rozelle Interchange. It is the first new road crossing of the harbour in over 30 years.
Additionally, the tunnel’s twin three-lane motorways are expected to reduce traffic on the Western Distributor by 35%, the harbour tunnel by 20% and the harbour bridge by 17%.
Comprising of creating the 1.7km southern section of the tunnel from Rozelle to Birchgrove, stage one is undergoing and is expected to be complete next year and construction of the northern end of the tunnel, connections to the Warringah Freeway, tunneling underneath Sydney Harbour as well as completing tunnel fit-out, are the contents of stage two. The estimated time duration for completion of this project is approximately five years.
