The two giant overlapping tunnels that pass metres apart below Sydney

The government hopes the route will ease congestion on the Harbour Bridge, Harbour Tunnel, Anzac Bridge and Western Distributor.

Late next year, massive tunnel boring machines will be assembled at Birchgrove before they start to dig their way north under the harbour to Waverton.

The road-headers recently passed under North Sydney Council chambers on Miller Street, near Victoria Cross station, and are churning through 25 metres of rock per week en route to Waverton.

Each machine can excavate 1000 tonnes – equivalent to the weight of three Boeing 747-200 planes – of rock per day. Transport for NSW and stage two contractor Acciona are trialling a remote control road-header, which can be operated by workers 200 metres from the rock face, to carve the tunnels.

Construction of the first stage of the twin 1.7-kilometre tunnels from the WestConnex interchange at Rozelle to Birchgrove began in July 2022 and work is nearly complete.

Loading

The former Coalition government had decided to dig deeper tunnels for the main section of the motorway between Birchgrove and Waverton, ditching earlier plans to lay large tubes in a trench on the harbour floor.

NSW Labor has vowed to keep the Western Harbour Tunnel in public hands as part of a long-term strategy to increase the number of state-owned toll roads and reduce Transurban’s stranglehold on Sydney’s motorway network.

Our Breaking News Alert will notify you of significant breaking news when it happens. Get it here.