Sydney Metro West TBMs set historic record with double tunnel breakthrough

Sydney Metro West

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Sydney Metro West achieves a historic milestone as TBMs Daphne and Beatrice complete the first groundbreaking double tunnel breakthrough in the southern hemisphere.

Two tunnel boring machines (TBMs) have broken through a rock wall to arrive at Five Dock Metro Station and claim the title as the first TBMs in the southern hemisphere to complete a double breakthrough. 

The TBMs have achieved the first two breakthroughs for Sydney Metro West as work powers ahead to build twin 24-kilometre metro tunnels between Westmead and the Sydney CBD. 

TBM Daphne broke through first, followed closely by TBM Beatrice, after building the 4.3-kilometre section of metro tunnel from The Bays to Five Dock for around seven months. 

This breakthrough marks an important milestone in the Minns Government’s plan to build an enhanced Sydney Metro West project that also helps drive housing supply.

“This breakthrough at Five Dock is an important milestone as we progress towards the completion of this project and the creation of thousands of new homes,” says NSW Premier Chris Minns.

“We’re building this major public transport project at the same time as we’re turbocharging the creation of new housing in our state. We know more supply is the key to making housing more affordable,” says NSW Premier Chris Minns.

“This project won’t just change the way people move around our city; it will now also provide the well-located homes for future generations to live in,” says NSW Premier Chris Minns.

The two 1,300-tonne machines will spend the next few weeks traversing to the western end of the station cavern. During this time, the machines will undergo all necessary maintenance before being relaunched to continue their journey to Sydney Olympic Park. 

To date, the huge machines have excavated a total of 437,463 tonnes of material each and installed about 30,732 precast concrete segments to line the new tunnel walls. 

This once-in-a-century infrastructure investment will also double rail capacity between Greater Parramatta and the Sydney CBD, making it easier and faster to travel around western Sydney; link new communities to rail services and support employment growth and housing supply.   

The NSW Government is also reaffirming its commitment to building more housing in the right places, where people want to live – to improve affordability, reduce building and infrastructure costs and create thriving communities. 

“Now this is truly ground-breaking – never before has a project in the southern hemisphere achieved what we are seeing right here with this double breakthrough,” says Transport Minister Jo Haylen.

“Record-breaking milestones like this offer a snapshot at the sheer scale and ambitious nature of Sydney Metro West, that will completely transform this great city,” says Transport Minister Jo Haylen.

“Sydney Metro West will transform travel in Sydney’s west including right here in Five Dock, a location that will welcome its very first railway connection to put both the Sydney CBD and Western Sydney at its doorstep,” says Transport Minister Jo Haylen.

This includes a proposal, which was brought to the NSW Government by the ATC, centering around the potential to build more than 25,000 new homes on the Rosehill Racecourse site. This would allow the government to explore the feasibility of a new Metro West Station at Rosehill. 

To prepare for the arrival of the TBMs, the Five Dock station cavern was excavated with about 286,047 tonnes of material removed to create the underground box-like structure that is 22 metres wide and 30 metres deep.  

Next stop for the TBMs is the Burwood North Metro Station site about two kilometres away, where they are due to arrive in early 2024. 

TBM Beatrice and Daphne fast facts

  • TBMs are double-shield, hard rock TBMs specifically designed to excavate through the sandstone and shale ground conditions.   
  • A team of 15 workers per shift operate the TBM as it excavates an average of 200m per week.  
  • The TBMs are 165m long (more than the length of 2x A380’s which are approximately 73m).  
  • TBMs are built using refurbished cutterheads, front shields and gripper shields from TBMs used on the Sydney Metro City & Southwest project.  
  • Each TBM is approximately 7m in diameter.  
  • 34x disc cutters per cutterhead (disc cutters are approx. 48cm in diameter).  
  • Heaviest pieces of the TBM are the front shield and gripper shield both approx. 280 tonnes each, the cutterhead is approximately 102 tonnes.
  • The two 1,300-tonne machines will spend the next few weeks traversing to the western end of the station box cavern.
  • During this time, the machines will undergo maintenance before being relaunched to continue their journey to Sydney Olympic Park.
  • The Five Dock station box cavern was excavated with about 286,047 tonnes of material removed to create the box-like structure that is 22m wide and 15m deep. 
  • Next stop for the TBMs is the Burwood North Metro Station site about two km away, where they are due to arrive in early 2024. 
  • TBMs Beatrice and Daphne are 2 of 6 TBMs building the tunnels for the new Sydney Metro West line connecting Greater Parramatta to the Sydney CBD.  
  • A total of 30,732 precast concrete segments have been installed by both TBMs to line the new 7m wide tunnels. 
  • Two TBMs are currently tunnelling between Sydney Olympic Park and Westmead, while the final fifth and sixth TBMs will launch in 2024, starting at The Bays, moving under harbour to Pyrmont and onto Hunter Street.

Source: © Sydney Metro 2023

Source: © NSW Government 2023

Image Source: © Sydney Metro 2023

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