Since being launched from Cherrybrook on Monday 3 November 2014, tunnel boring machine (TBM) 3 has completed more than 75 per cent of her 6 kilometre journey and her final destination which is Epping is now just over 1 kilometre away. Like all of our TBMs, Isabelle continues to work hard.
So far she's excavated more than 350,000 tonnes of sandstone and shale, been home to 50 workers across three shifts, and installed 14,850 concrete segments to line the new rail tunnel. In late March, Isabelle also had the distinction of being the first TBM to reach the deepest point along the tunnel alignment - 58 metres underground beneath Thompson's Corner at West Pennant Hills. Sydney Metro Northwest is the first transport infrastructure project in Australian history to use four tunnel boring machines at once. You can monitor the whereabouts of all four TBMs by viewing our TBM tracker.