Cross River Rail’s first mega machine to “disappear” under Brisbane

The first of Cross River Rail’s two huge Tunnel Boring Machines (TBMs) is now underground, and will only re-emerge later this year after it has finished tunnelling under the Brisbane River and CBD.

TBM Else – named after trailblazing female engineer Else Shepherd AM – has been moved into position underground in the Woolloongabba site’s station cavern to commence tunnelling later this month.

The milestone marks the start of Cross River Rail’s year of tunnelling in 2021, and was marked by a traditional indigenous blessing ceremony to wish TBM Else and the tunnellers safe passage as they make their way underground.

TBM Else will not see the light of day until she emerges from the project’s northern portal at Normanby towards the end of the year.

Cross River Rail’s other 1350-tonne mega machine – TBM Merle – will follow shortly after to ensure the project’s twin tunnels are completed before the year is out.

The TBMs have one of the most crucial jobs of the entire project – excavating the bulk of Cross River Rail’s 5.9 kilometres of twin tunnels right under the Brisbane River and CBD.

The TBMs will tunnel through 20 to 30 metres of hard rock a day, with a crew of up to 15 people working on them at any one time.

From Woolloongabba, the TBMs will tunnel under the river and break through to Albert Street station at a depth of 31 metres in mid-2021 and continue to Roma Street before emerging at the project’s northern portal at Normanby.

The TBMs will line the tunnel walls as they go with 25,000 massive precast concrete segments, weighing 4.2 tonnes each.

 

Tunnel Boring Machine fast facts:

  • Each TBM weighs 1350 tonnes and is 165 metres long;
  • More than 40 truck movements are required to transport each TBM to site in parts;
  • A crew of up to 15 people will work in a TBM at any one time;
  • TBMs will work at a rate of 20 to 30 metres per day;
  • The TBMs will install 25,000 concrete segments weighing 4.2 tonnes each along the tunnel walls as they go;
  • At their deepest point the tunnels will be 58m below the surface at Kangaroo Point, and 42m below the Brisbane River;
  • Each TBM is fully equipped with crew facilities, offices and toilets;
  • The TBMs will generate 290,000 cubic metres of spoil as they make way for the twin Cross River Rail tunnels.