The second of two TBMs has commenced excavating on Sydney’s Western Harbour Tunnel project.
Launched 44.7m below Birchgrove Oval, TBM Barangaroo has begun the drive on the final section of the twin motorway tunnels between Birchgrove and Waverton.
Barangaroo joins its sister TBM, Patyegarang, which Stage 2 contractor Acciona launched in June. Together, the pair will excavate the final 1.5km beneath the Sydney Harbour and complete the last stage of tunnelling for the 6.5km Western Harbour Tunnel.
The John Holland and CPB joint venture completed roadheader excavation on Stage 1 in December 2024 and the tunnels were then handed over to Acciona.
At 15.7m in diameter and weighing 4,350 tonnes each, the two CREG-manufactured TBMs are the largest ever assembled underground, and the largest to be used in the Southern Hemisphere.
As they advance, they will install around 13,000 pre-cast concrete segments and 1,300 20-tonne culverts manufactured at a dedicated facility in Emu Plains.
During the launch process, Barangaroo will construct the first three tunnel rings, each using 10 of the 15-tonne segments, before pushing through the launch chamber wall and starting its journey.
Named after prominent Aboriginal women and decorated with indigenous artwork, Patyegarang and Barangaroo will operate around the clock and reach depths of up to 50m below sea level.
The tunnelling comes as another key milestone, the Berry St on-ramp in North Sydney on the other side of the Harbour, nears completion.
The future connection will link motorists to the WestConnex via the Rozelle Interchange.
Mechanical and electrical fit out is progressing, including lighting, traffic monitoring cameras and signage that will support the tunnel’s safe operation when it opens.
The New South Wales government says the Western Harbour Tunnel remains on track to open to traffic in 2028. It is designed to reduce traffic on the Western Distributor by 35%; the Sydney Harbour Tunnel by 20%; the Sydney Harbour Bridge by 17%.
Minister for roads and regional transport Jenny Aitchison said TBM Barangaroo’s launch TBM was another “exciting milestone” for the Western Harbour Tunnel project.
“With both tunnel boring machines now in action, we are making strong progress on the final stage of excavation for this important Harbour crossing,” she said.
“It’s taken extraordinary feats of engineering to get to this point, and the teams who’ve assembled and launched the TBMs entirely underground have done an outstanding job.
