By Lynda Myer
Digging process of the second phase of Sydney’s Western Harbour Tunnel, has been started by Acciona.
While providing of a temporary access tunnel beneath the road reserve, is undergoing by the first roadheader, from there, TBMs are due to begin the twin mainline tunnels, continuing south under the highway towards Ridge Street, North Sydney.
In order to starting tunnel excavation on the north side of the harbour, Acciona will use a total of 10 roadheaders, each with a height of 5m, a width of 4.5m and weighing over 100 tonnes.
With weekly excavating performance of 20-25m, the roadheader will cut through 1,000 tonnes of rock a day, before a TBM takes over to tunnel under the harbour.
To date on stage 2, 23,000 tonnes of material have already been excavated and more than 1,482m3 of concrete poured in preparation for tunneling.
Intending to decrease traffic on the Sydney Harbour Bridge and tunnel by linking the Warringah Freeway with the soon to open Rozelle Interchange,the Western Harbour Tunnel project is slated to create around 7000 jobs and is a 6.5km tunnel. It is the first new road crossing of the harbour in over 30 years.
Additionally, the reduction of traffic on the Western Distributor by 35%, the harbour tunnel by 20% and the harbour bridge by 17%, is expected by advancing tunnel’s twin three-lane motorways.
The scheduled date for completion of the stage one, which is under way and comprises of creating the 1.7km southern section of the tunnel from Rozelle to Birchgrove is 2025, while the expected time period for stage two, which includes construction of the northern end of the tunnel, connections to the Warringah Freeway, tunneling underneath Sydney Harbour and the complete tunnel fit-out, is approximately five years.
According to Minister for roads John Graham: “The start of tunneling at Cammeray is a major milestone for this project, bringing motorists a step closer to benefiting from Sydney’s third harbour crossing. The new Western Harbour Tunnel will provide time-saving benefits not only for those connecting to the Rozelle Interchange, but for motorists across Sydney’s wider road network.”
In December 2022, Acciona was granted the design and construction contract for stage two and the awarded total budget is AU$4.24bn (£2.22bn).
