An international search is under way for a supplier to build the four Tunnel boring machines (TBMs) required to build Melbourne’s $11 billion Metro Tunnel.
The four machines need to be more than 100 metres long, weigh up to 1000 tonnes and be custom-built to grind through the site’s unique ground conditions, according to a statement from the Victorian Government.
Once built and tested, the TBMs will be delivered and launched to sites at Arden and Domain where they will be lowered into the ground and reassembled on-site.
After they are launched, they will work up to 40 metres below Melbourne’s surface, progressively installing concrete linings to support the excavated tunnel and operating 24/7 in 2019.
Each TBM will include offices, kitchens and toilets, and be operated by a crew of around 15 people.
Works are currently under way at City Square where construction crews will dig 11 storeys below the ground to build a new underground station.
The Victorian Government says the project will create nearly 7000 local jobs and will be completed in 2026.