The largest tunnel boring machine (TBM) in the Southern Hemisphere has started digging the West Gate Tunnel.
The massive TBM, named Bella, was sent on its journey under Melbourne’s western suburbs to build the alternative to the West Gate Bridge.
It is now working its way through the earth below Yarraville and will travel for 18 months, excavating the four-kilometre outbound tunnel that will meet up with the West Gate Freeway in Altona North.
The second TBM, named Vida, will soon begin work on the 2.8-kilometre inbound tunnel.
The TBMs are named after Bella Guerin and Vida Goldstein.
The TBMs are 15.6 metres in diameter and 90 metres long, weighing in at 4000 tonnes each, which is about the same as 20 Boeing 747 airplanes.
They are equipped with a state-of-the-art computerised navigation system and will dig through an average of nine metres per day. They have been specifically chosen for their ability to work deep underground with almost no disturbance above ground for traffic, businesses and residents.
The TBMs are being piloted by a highly trained specialist crew who will work around the clock while the tunnel is being built.
While the TBMs bore through the earth, a mobile factory behind them will install massive concrete rings to form the structural and waterproof lining of the tunnel.
Crews of up to 20 people will then work to build the road surface and install electrics, ventilation and safety systems.
Excavated soil will be taken to a specially built facility operated by Hi-Quality in Bulla.
The TBMs have been through a thorough testing and commissioning phase within the project site in Yarraville to ensure they’re working effectively before commencing their journey.
A joint venture consisting of John Holland and CPB Contractors is the subcontractor delivering the project.
The West Gate Tunnel Project will deliver an alternative to the West Gate Bridge, with new twin tunnels under the Yarra river connecting the West Gate Freeway on Melbourne’s west to the Port of Melbourne in the city’s south-west.
The tunnels will help take trucks off residential streets, providing a more efficient freight route.
The West Gate Freeway is also being widened from eight to 12 lanes and will include express lanes between the M80 and the West Gate Bridge, reducing weaving and merging that leads to traffic congestion.
Widening works on the West Gate Freeway are now 70 per cent complete, with new Hyde St ramps, new connections from the CBD and 14 kilometres of new walking and cycling paths on the way.
The project was originally due to be completed this year but now has a completion date of 2025.
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