Cross River Rail’s mega machines power under CBD

Cross River Rail’s two massive Tunnel Boring Machines are forging their way beneath Brisbane’s CBD, with the first now below the project’s new Albert Street station site.

TBM Else has reached the Albert Street site and will soon be excavating below the station cavern, while TBM Merle is following closely behind, currently beneath the Botanic Gardens.

The construction milestones just keep coming for the transformational Cross River Rail mega-project during its year of tunnelling.

Already we have seen the TBMs launch from Woolloongabba and tunnel below the Brisbane River and now TBM Else has reached the site of what will become the CBD’s first train station in more than 120 years.

There are challenging geological conditions at Albert St, including Brisbane’s notoriously hard Neranleigh-Fernvale rock beds, but the TBMs will power under what has been excavated of the station cavern so far and site crews will continue to use controlled blasting to finish the station box excavation.

The benefit of this approach is that the mega machines will end up excavating about a quarter of the station cavern.

This means over 24,000 cubic metres of spoil will be removed using the TBMs’ conveyors and via Woolloongabba, which equates to 2,000 truck and dog movements that will not have to be transported the inner city.

Controlled blasting will also reduce the impact of station construction on local residents and businesses.

The project’s contractors assure us this method is a more appropriate way to excavate at the site given the hard rock present.

More than 2,500 workers are currently employed on the project, which is injecting over $4 million a day into the economy.

Cross River Rail is providing employment opportunities and an economic boost right when our state needs it the most.

After the TBMs traverse the Albert Street site, they will continue on to Roma Street where they will break through later in the year before finally emerging at the project’s northern portal near Normanby by the end of 2021.

To follow Cross River Rail’s TBMs and roadheaders on their journeys, visit our TBM Tracker.

Cross River Rail tunnelling fast facts:

  • The two TBMs are named in honour of two groundbreaking Queensland women – trailblazing engineer Else Shepherd AM and pioneering feminist Merle Thornton AM;
  • Each TBM weighs 1,350 tonnes and is 165 metres long;
  • A crew of up to 15 people will work in a TBM at any one time;
  • TBMs work at a rate of 20 to 30 metres per day;
  • TBMs excavate the bulk (about 3.5km) of Cross River Rail’s 5.9km of twin tunnels, with the rest excavated by roadheaders;
  • The TBMs will install over 25,000 concrete segments weighing 4.2 tonnes each along the tunnel walls as they go;
  • At their deepest points, the tunnels are 58 metres below the surface at Kangaroo Point, and 42 metres below the Brisbane River;
  • Each TBM is fully equipped with crew facilities, offices and toilets;
  • The TBMs will generate 315,000 cubic metres of spoil as they make way for the twin Cross River Rail tunnels.