Construction on Sydney’s first new road harbour crossing in more than 35 years is powering ahead, with the first of two massive tunnel boring machines (TBMs) set to reach the halfway mark in its journey from Birchgrove to Waverton this week.
The underground excavation crews beneath Waverton have completed two enormous underground receiving chambers, marking another critical milestone for the Western Harbour Tunnel project.
The newly finished chambers will act as the arrival destination for the twin TBMs, which are currently carving out the final 1.5-kilometre section of the tunnel beneath Sydney Harbour at depths of up to 50 metres.
Upon completing their underwater journey, the TBMs will break through into the purpose-built underground caverns, connecting the new harbour tunnels with the previously excavated 2.8-kilometre stretch running between Cammeray and Waverton.
Standing up to 23 metres high, 35 metres wide, and 34 metres long, the receiving chambers are a substantial engineering achievement.
Designed and excavated using specialised roadheaders, the space allows the southern hemisphere’s largest TBMs to be safely dismantled underground. Their massive cutterheads and shields will be detached, shifted sideways, and permanently sealed into the surrounding bedrock.
Once completed, the new connection will link motorists directly to WestConnex via the Rozelle Interchange, creating a major alternative route across the city.
New South Wales Minister for Roads Jenny Aitchison noted the scale of the ongoing engineering work deep below the harbour.
“The Western Harbour Tunnel is taking shape deep beneath Sydney harbour, and these two major milestones show just how much progress is being made on this once-in-a-generation project,” Aitchison said.
“As the first tunnel boring machine is reaching the halfway point beneath the harbour, crews on the North Shore have completed two enormous underground chambers ready to receive these engineering giants.”
Western Harbour Tunnel remains on track for completion in 2028, with projections indicating it will reduce traffic by 35 per cent on the Western Distributor, 20 per cent in the Sydney Harbour Tunnel, and 17 per cent on the Sydney Harbour Bridge.