Four tunnel boring machines digging the twin nine-kilometre Metro Tunnel in Melbourne have completed their work after 20 months of construction.
The Metro Tunnel project will add five new underground stations in the busy Metropolitan Melbourne, with the nine-kilometre rail tunnel running from the west of the city to the south-east as part of a new Sunbury to Cranbourne/Pakenham line.
Melbourne Airport Rail services will also run through the Metro Tunnel to maximise access for all Victorians and provide passengers with an under 30-minute service from the airport to the CBD.
This week, the last tunnel boring machine reached the finish line at the new Town Hall Station, joining the other three machines that had arrived at the site over the past months.
The four tunnel boring machines, Joan, Meg, Alice and Millie, have lined tunnels from South Yarra to Kensington, moving through over 250,000 tonnes of concrete, including tunnelling an average of 90 metres per week.
TBMs Joan and Meg – dug their final 670 metres under Swanston Street from the State Library Station site over the past three months. TBMs Millie and Alice – began tunnelling in December to complete their final 1.8km leg under St Kilda Road and the Yarra River.
With their work in Melbourne finished, the four TMBs are now being dismantled, with the components being assessed for possible re-usability for other tunnelling projects.
The Metro Tunnel is set to be completed by 2025, with included works also set to complete the final section of tunnels alongside platforms at Town Hall Station.
Once complete, the tunnel will help untangling the City Loop in Melbourne rail, allowing more trains to run more often across Melbourne.