Tunnel boring is now complete on the two twin tunnels that will create a much-needed alternative to the congested West Gate Bridge.
The West Gate Tunnel Project marked a major milestone with Tunnel Boring Machine (TBM) Bella breaking through in South Kingsville, completing a 4km journey from the west side of the Maribyrnong River under Yarraville, to just east of Millers Road near the West Gate Freeway.
Over the past fifteen months, TBM Bella has operated 24/7, excavating over 700,000 cubic metres of rock and soil while installing more than 15,340 individual concrete segments to create the tunnel walls.
The significant milestone comes just two months after TBM Vida completed her journey, marking the largest tunnel breakthrough to occur in the southern hemisphere.
TBMs Bella and Vida have been steadily digging their way under Yarraville, 24/7, creating the two twin tunnels that will create an alternative to the West Gate Bridge.
What happens now that digging is finished
TBM Bella will be dismantled and removed piece by piece, with the 450-tonne cutterhead buried on-site, and other components either recycled or returned to the manufacturer.
Crews will continue the important work of building the road deck and installing electrical, lighting and safety systems to prepare both tunnels for completion in 2025.
Above ground, work is now underway to construct the ventilation system at the outbound portal and prepare for the installation of the iconic eel net structure.
TBM Bella and Vida Fast Facts
- Bella and Vida are currently the largest TBMs in the southern hemisphere.
- They weigh in at a hefty 4000 tonnes each and are 90m long.
- They’re 15.6m high – that’s almost as big as Flinders Street station.
- The cutterhead alone weighs 450 tonnes (about 9 Melbourne trams).
- The cutterhead features 96 cutting tools and will rotate up to twice per minute during normal tunnelling operation and up to 3 times per minute when cutting through the hard basalt rock section and through the “bluestone” that Melbourne’s geology is famous for.
- Bella and Vida have excavated more than 1.5 million cubic metres of rock and soil from the tunnel.
- The TBMs have been running 24 hours a day, 7 days a week, boring up to 9m a day.
Thank you
As a thank you to the local community for their patience during construction works and to celebrate this important milestone, a community day was held on Saturday 6 May 2023 at the Information Centre.
Why are we building the West Gate Tunnels
The new twin tunnels give drivers the option of the bridge or the tunnel ensuring quicker and safer journeys and will help remove over 9000 trucks a day from streets in the inner west.