Sydney Metro Northwest (formerly the North West Rail Link) is the first transport infrastructure project in Australian history to use four tunnel boring machines at once – highlighting the sheer size of this world-scale infrastructure project which is delivering Australia’s longest railway tunnels, 15km twin tunnels from Bella Vista to Epping.

In March 2015, Isabelle – the third of our four tunnel boring machines – reached a project milestone by excavating to the alignment’s deepest point – 58m beneath Thompson’s Corner at West Pennant Hills.