Four giant Tunnel Boring Machines (TBMs) are needed to dig the Metro Tunnel.

Lowered into the ground at North Melbourne and St Kilda Road in pieces and then assembled, they operate as moving factories travelling deep under Melbourne.

TBMs perform two main tasks:

• Excavating rock and soil with a rotating cutter head at the front of the machine before it is transported via pipes running through and behind the TBM.
• Progressively installing curved concrete segments to create a watertight lining inside the tunnels.

Track their journey

Our first TBM is making its way across the sea to Melbourne, track its progress on our tracker.

For more information please visit https://metrotunnel.vic.gov.au/ .02/19