Two 7m diameter TBMs working on the Sydney Metro 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 Herrenknecht double-shield, hard rock, gripper-type TBMs, driven by the Acciona Ferrovial Joint Venture have achieved the first two breakthroughs for Sydney Metro West as work powers ahead to build twin 24km metro tunnels between Westmead and the Sydney CBD.
TBM Daphne broke through first, followed closely by TBM Beatrice, after building the 4.3km section of metro tunnel on the project’s $1.96bn Central Package from The Bays to Five Dock for around seven months.
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 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.
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 22m wide and 30m deep.
Next stop for the TBMs is the Burwood North Metro Station site about 2km away, where they are due to arrive in early 2024.
These are the first of six TBMs being used to build the 24km of tunnels from the Sydney CBD to Parramatta, which have been split into three sections.
John Holland, CPB Contractors (CPB) and Ghella joint venture (JCG JV) will deliver the Eastern Tunnelling Package featuring 3.5km of metro rail tunnels between The Bays and Hunter Street in the Sydney CBD, whilst the Gamuda Australia/Laing O’Rourke Consortium has been awarded the $2.16bn Western Tunnelling contract to deliver 9km of twin metro rail tunnels between Sydney Olympic Park and Westmead.
Sydney Metro West will double the rail capacity between Sydney’s two biggest CBDs once passenger services commence in 2030.