Tunnelling hits halfway mark for Metro Tunnel

Two giant tunnel boring machines (TBMs) have broken through key sections of the Metro Tunnel, marking the half-way mark of tunnelling on the ground-breaking project.

TBM Meg broke through at the new Parkville station on Saturday, less than 24 hours after TBM Millie completed its journey from Anzac Station to South Yarra.

The dual breakthroughs mark a major milestone in the project, with 50 per cent of the tunnelling now completed.

Construction on the Metro Tunnel has continued throughout the coronavirus pandemic, with more than 1,800 workers adhering to strict COVID-19 safety measures to keep the project going.

The TBMs have so far excavated more than 364,000 cubic metres of rock and soil and installed more than 30,000 individual concrete segments, each weighing 4.5 tonnes, to line the tunnel walls.

Both Meg and Joan, which broke through at Parkville Station in late August, are being moved through the station site before being cleaned and recommissioned.

TBM Joan will be relaunched in the coming weeks to dig towards the new State Library Station, with TBM Meg following soon after.

TBM Millie’s cutterhead and shield will be lifted out of the South Yarra tunnel entrance site by crane then transported to the Anzac Station site. The rest of the TBM will be pulled back through the tunnel to Anzac Station, then reassembled and relaunched towards Town Hall Station later this year.

The four TBMs are named after ground-breaking women: Victoria's first female Premier Joan Kirner, Australian women's cricket captain Meg Lanning, Victoria's first female Member of Parliament Lady Millie Peacock and wartime medical hero Alice Appleford.

The Metro Tunnel will create additional capacity for more than half a million passengers a week during peak periods and transform the way Victorians travel around Melbourne.

The project will connect the Sunbury line to the Cranbourne and Pakenham lines via two nine kilometre tunnels up to 30 metres below Melbourne with five new underground stations, and links to the existing network at key locations.