Construction progress

• In January 2026, the Western Harbour Tunnel project started assembling the project’s two giant tunnel boring machines within 120 metre long TBM launch chambers beneath Birchgrove. Workers are manoeuvring 167 oversized components into place in extremely tight conditions, often with barely 1.5 metres of clearance between machinery and the chamber walls.

• A standout achievement was rotating and lifting the 462 tonne, 15.7 metre wide cutter head into position, a task requiring precision sequencing and months of planning. Assembling the TBM is like completing a massive underground puzzle, with project construction contractor ACCIONA choreographing the exact order in which each piece must be transported, lowered, and fitted together.

• The first TBM, Patyegarang, is now close to full assembly, while the second, Barangaroo, is progressing through the same intricate underground assembly. Together, the machines represent one of the most complex TBM assembly efforts ever attempted beneath a major city. 

• In November 2025, the Western Harbour Tunnel project successfully transported the first TBM part – the cutterhead of our first TBM, Patyegarang - into the TBM launch chamber under Birchgrove. Moving the 15.7metre wide, 274 tonne TBM part from Glebe Island into the tunnel required meticulous planning and specialised heavy lift equipment.

• Its journey took place at night under police escort, using a self propelled modular transporter (SPMT) designed to handle extremely large loads on urban streets. Operated remotely by a technician walking alongside it, the SPMT enabled millimetre-level precision as it navigated public roads, gradients, and confined tunnel spaces.

• The transporter’s 128 wheels distributed the cutterhead’s immense weight evenly, ensuring stability and protecting road and tunnel surfaces throughout the move. This successful delivery marked athe start of our underground assembly of the massive TBMs that will excavate twin tunnels from Birchgrove to Waverton. 

• A milestone has been reached in the transformation of Berrys Bay - the Draft WHT Place, Design and Landscape Plan Part 2 was on public display between 28 July and 24 August 2025.​

• Originally earmarked for Western Harbour Tunnel work, Berrys Bay is set to become a spectacular new harbourside park, unlocking community access to this iconic waterfront site for the first time in more than a century.​

• The plan marks a pivotal moment in the revitalisation of the historic Waverton precinct, part of the NSW Government’s broader commitment to delivering open, inclusive spaces for communities across the state.​

• In collaboration with North Sydney Council, we have worked to ensure the design respectfully honours Berrys Bay’s rich maritime legacy and deep Aboriginal history, while shaping a vibrant community space for generations to come.

• The largest tunnel boring machines (TBMs) ever used in the Southern Hemisphere  officially passed their factory acceptance testing.

• Each mega-TBM spans 102 metres in length, which is about the same size as a soccer field, and measures 15.7 metres in diameter, weighing a staggering 4,350 tonnes. 

• The cutterheads of the TBMs are adorned with commissioned artwork that pays tribute to the legacy of Aboriginal women, Barangaroo and Patyegarang.

• The designs were created by Aboriginal artist Taleena Simon to honour Sydney’s First Nation's heritage and the deep connection to Country that continues to shape the city’s identity.​

• Assembly of the TBMs will take place in launch chambers deep below Birchgrove, using a 500-tonne crane to position the giant components with precision.

• A major milestone was reached as two of NSW’s largest infrastructure projects, Western Harbour Tunnel (WHT) and the Warringah Freeway Upgrade (WFU) officially connected underground.

• A 95-tonne roadheader broke through the final centimetres of rock, linking the two projects for the first time.​

• At this point in the project Western Harbour Tunnel roadheaders had carved through an extraordinary one million tonnes of Sydney sandstone, equal in weight to nearly 7,000 blue whales.​

• The connection represents a significant leap forward for both state-significant projects, reinforcing the NSW Government’s commitment to building smarter, faster routes through one of the nation’s busiest corridors.​

• Since mid-2021, teams on the WFU project have been preparing the way for WHT, creating vital space for the tunnel to integrate with the wider road  network.

• Stage 1 of the Western Harbour Tunnel project was completed in February 2025.

• This section of Western Harbour Tunnel, constructed by John Holland CPB Contractors (JHCPB), involved excavating 1.7 kilometres of tunnel from below Emily Street, Rozelle, to Cove Street, Birchgrove.

• Continued excavation of the tunnels from Birchgrove under Sydney Harbour and the complete tunnel fit-out are being carried out by WHT Stage 2 contractor, ACCIONA.

• 12 months into construction starting in November 2023, on Stage 2 of the Western Harbour Tunnel project,  tunnelling was more than 60 per cent complete, with having passed above the Sydney Metro tunnel at North Sydney on its way towards Waverton. 

• November 2024 marked the 12-month anniversary of the start of Stage 2 tunnelling from the Warringah Freeway at Cammeray, with 2.9 kilometres of twin three-lane road tunnels excavated by six roadheaders working around the clock.

• So far, 5,800 people have worked on Stage 2, further enhancing the combined skills of the underground construction workforce in NSW. 

• Tunnelling has recently passed underneath North Sydney and is progressing about 25 metres a week towards the harbour.

• The design of Western Harbour Tunnel, Sydney Harbour’s third road crossing in more than 30 years, features twin three-lane tunnels.

• The final in-tunnel concept incorporates visual elements that honour Country, celebrating land, water, and culture, and integrating public art throughout.

• When the tunnel is operational, motorists will experience public art installations that reflect the area’s deep Aboriginal cultural significance, creating a meaningful connection between infrastructure and heritage.

The Western Harbour Tunnel project's modification has been approved by the Department of Planning, Housing & Infrastructure, allowing the use of tunnel boring machines (TBMs) instead of the originally planned immersed tube tunnel (IMT), for the section under Sydney Harbour. This change will reduce environmental and community impacts by eliminating dredging and reducing construction support sites. The TBMs will create twin 1.5km tunnels under the harbour between Birchgrove and Waverton. The modification underwent public consultation, and feedback was considered in the decision-making process. 

The TBM method eliminates the need for dredging in Sydney Harbour, minimising impacts on the marine environment. It also removes the need for cofferdams in the harbour, which would have been required for the IMT method. ​

Fewer construction support sites are needed, and the disruption from construction activities in areas like Birchgrove and Waverton is reduced. 

• Stage 2 of Western Harbour Tunnel has marked a major milestone with excavation underway at Cammeray, led by a 100-tonne roadheader - equivalent in weight to 27 elephants. 

• The machine is cutting south toward the Warringah Freeway and Waverton, progressing at up to 25 metres per week. Over the construction phase, up to 10 roadheaders will be deployed. 

• At this early stage in the project. we have already removed more than 23,000 tonnes of rock and poured 1,482 cubic metres of concrete. 

Early work on Western Harbour Tunnel Stage 2 started with investigations at all work locations including Ridge Street, Cammeray, Berrys Bay, Birchgrove and Rozelle. Other site establishment work includes: 

• installing fencing and environmental controls 

• earthwork and roadwork within the site boundary 

• removing vegetation and installing tree protection zones 

• installing, relocating and connecting to utilities (e.g. power, water, stormwater and communications) 

• delivering machinery, equipment, and other materials to the site 

• construction of temporary site offices.

Contract Award: $4.24 billion contract awarded to ACCIONA. 

Stage 2 Scope: Construction of the northern end of the tunnel, connections to the Warringah Freeway, and the harbour crossing. ​

Tunnelling Method: Shifted from immersed tube tunnel to tunnel boring machines (TBMs). ​

Timeline: Stage 2 construction began in late 2023 and is due to be completed in 2028.  

Benefits: Will provide a western bypass of the CBD, reduce traffic congestion on other routes, and cut travel times. 

• Stage 1 of Western Harbour Tunnel commenced on 29 June 2022 with excavation work at Emily Street, Rozelle.

• This initial stage focuses on the southern section of the tunnel, extending from Rozelle to Birchgrove.​

• Geotechnical investigations and groundwater monitoring began earlier in February 2022, providing critical data to inform the detailed tunnel alignment design.​

• Stage 1 is dedicated exclusively to excavation and does not include any tunnel fit-out activities.

• Stage 1 tunnelling is projected to be completed in 2025, aligning with the broader timeline for overall project completion.