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 4km 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 2.8km inbound tunnel.
The TBMs are named after Bella Guerin and Vida Goldstein.
The TBMs are 15.6m in diameter and 90m 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 9m 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.