Tunnelling milestone reached on Sydney’s Rozelle Interchange

8 April 2021

Tunnelling on the Rozelle Interchange – a key component of Australia’s biggest road infrastructure project – has now reached the halfway mark, with 12km excavated.

Seen as a vital component of the US$12.8bn WestConnex road project, along with the Iron Cove Link and M4-M5 tunnels, the Rozelle Interchange will provide a new underground motorway complex comprising 24km of tunnels, caverns, passages, temporary access declines and ventilation shafts. In some sections, the super-complex will have tunnels arranged over three levels. When finally completed, the interchange and Iron Cove Link will connect with the City West Link and the proposed Western Harbour Tunnel.

Excavation by the John Holland and CPB Contractors Joint Venture is being undertaken on a 24/7 basis. The JV is using a total of 22 roadheaders advancing from four different sites and working to a top heading and bench configuration, using rockbolts and shotcrete for primary support. The machines have encountered a geology of mainly Hawkesbury Sandstone, weathered rock and residual soils.

Creating the tunnelled interchange is freeing up space on the surface above, transforming unsightly old rail yards into green space: the Rozelle Parklands will provide 10ha of public park and open space facilitating leisure activities such as walking, cycling, playing and picknicking.

More than 9,000 workers have so far worked on Rozelle and Iron Cove Link, both of which are being delivered by Transport for NSW. Completion is scheduled for late 2023.