In a rare last look underground, the tunnel boring machines that will excavate Sydney's next harbour crossing are being seen for the final time before tunnelling begins.
Deep beneath Birchgrove Oval, the mega machines are in the final stages of assembly inside the cathedral-like launch chambers, ahead of disappearing beneath Sydney Harbour to tunnel the final section of the Western Harbour Tunnel.
The Minns Labor Government is delivering Sydney's first road harbour crossing in three decades - on time and on budget - and keeping it in public hands.
Once tunnelling starts later this year, the machines will operate continuously beneath the harbour - making today the final opportunity to see them before excavation begins.
The two TBMs, the largest in the Southern Hemisphere, are in the final stages of being meticulously reassembled using 500-tonne cranes - an engineering feat never before undertaken at this scale in Australia.
Named Patyegarang and Barangaroo, the TBMs are tasked with excavating 1.5 kilometres of twin motorway tunnels between Birchgrove and Waverton, up to 50 metres below sea level.
Assembly of Patyegarang is now 45 per cent complete, with its 15.7-metre-diameter cutterhead - weighing 462 tonnes - lifted into position last week. Around 70 per cent of the machine's components have now been transported into the launch chamber.
Patyegarang is expected to begin tunnelling under the harbour mid-year.
Assembly of Barangaroo is now 20 per cent complete, with tunnelling expected to commence later in 2026.
Once excavation begins, the TBMs will operate 24 hours a day, seven days a week, with up to 40 workers on each machine at any one time. The tunnels will be lined with around 13,000 precast concrete segments manufactured at a specialist facility in Western Sydney - showcasing the Minns Government's commitment to domestic manufacturing and procurement.
Overall excavation across the Western Harbour Tunnel project is now 76 per cent complete.
The 6.5-kilometre Western Harbour Tunnel is scheduled to open to traffic in 2028, and under the Minns Labor Government, will remain in public ownership.
Minister for Roads, Jenny Aitchison said:
"This is a major milestone for one of the most complex infrastructure projects ever undertaken in Australia.
"These machines are almost ready to disappear underground and do some of the hardest work on this mammoth project, carving a new harbour crossing that will serve Sydney for generations.
"The Minns Labor Government is proud to be delivering the Western Harbour Tunnel and keeping it in public hands.
"This is a once-in-a-generation piece of infrastructure, and it should remain an asset for the people of New South Wales - not a privatised road sold off to the highest bidder.
"With excavation now more than three-quarters complete, this project is moving forward.
"We made deliberate changes to the construction methodology to ensure this tunnel is built safely, properly and to deliver new public parkland at Berrys Bay.
"The Western Harbour Tunnel is on time and on budget, with overall excavation now at 76% complete."
