Sydney Moves Forward with Final Tunnelling for Harbour Project

Sydney is entering the final tunnelling stage of the Western Harbour Tunnel as two massive tunnel boring machines arrive later this year, marking a major milestone for the city’s infrastructure vision. This is reported by the railway transport news portal Railway Supply.

The 6.5-kilometre road tunnel will open in 2028 and remain publicly owned. It will create a second road crossing beneath the harbour, easing pressure on existing routes.

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Minister for Roads Jenny Aitchison said the Sydney project demonstrates long-term planning and transformative infrastructure. Each TBM is 102 metres long and weighs 4,350 tonnes—roughly four Freshwater ferries.

Measuring 15.7 metres in diameter, the TBMs are large enough to fit three Metro tunnels side by side. A 500-tonne crane will assemble them once the launch chambers are completed in 2026.

From Birchgrove, the TBMs will dig 1.5-kilometre twin tunnels under Sydney Harbour toward Waverton, operating 24/7 with around 40 workers per shift. Excavation will last approximately one year.

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The tunnels will include three lanes in each direction and use about 13,000 concrete segments, prefabricated in Western Sydney. These segments will form the tunnel lining and structural support.

In a nod to heritage, the TBM cutterheads will display artwork celebrating Aboriginal women Barangaroo and Patyegarang, blending Sydney’s rich history with future ambitions.

Stage 1 of the project finished in February 2025, delivered by John Holland and CPB Contractors. Stage 2 is underway under ACCIONA and will generate up to 6,900 full-time jobs during its construction phase.

Upon completion, the Western Harbour Tunnel will connect the Rozelle Interchange to the Warringah Freeway near North Sydney, supporting more efficient movement across the region.

Source, photo: www.felix.net

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