Tunnelling down under

Australia's Epping to Chatswood Rail Line is in the final stage of tunnelling between Macquarie Park and Chatswood. The project is using two Robbins rock TBMs working round the clock 5.5 days a week. The project, currently the largest publicly funded infrastructure contract in Australia, is part of a plan to increase CityRail network passenger capacity and expand routes.

The twin tunnels are each 12.5 km long and have an inner diameter of 7.2 m. The tunnels are being driven by a joint venture of design and construct contractors Thiess and Hochtief, and railway engineering company Alstom. Tunnelling will be completed this year for project commissioning in 2007.