Trackers let people see where machines are beneath Brisbane River

Mr Newton said the machines would arrive at Albert Street by the middle of 2021, before worming their way to Roma Street and finally emerging at the project’s northern portal at Normanby before the end of the year.

“Our TBMs are like underground factories – they’re 165 metres long and not only are they excavating the project’s twin tunnels, but they are lining the tunnels walls with 25,000 concrete segments along the way,” he said.

Four underground stations, at Roma Street, Albert Street, Woolloongabba and Boggo Road, will be built as part of the project.

The project was due to open in 2025.