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-kilometer 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.
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.
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 meters wide and 30 meters deep.
Next stop for the TBMs is the Burwood North Metro Station site about two kilometers away, where they are due to arrive in early 2024.