TBM1 sees light at the end of the tunnel

Three of Sydney Metro Northwest's four mega tunnel boring machines have now finished their job building Australia's longest ever railway tunnels.

TBM1 Elizabeth reached the end of the line in a rare night-time breakthrough on Tuesday 2 December 2015 after excavating 9km from Bella Vista to Cherrybrook. In September last year she became the first TBM to start digging on Australia's biggest public transport project, four months ahead of schedule.

Over the past 15 months, TBM1 Elizabeth:

• Excavated more than 700,000 tonnes of crushed rock, both sandstone and shale;
• Installed just over 28,000 concrete segments to line the new rail tunnel;
• Had 735 hardened steel cutters on her cutter-head replaced;
• Was home to tunnelling crews of 15 workers who have spent more than 100,000 hours underground;
• Achieved an average weekly tunnelling distance of 171 metres.

A series of operations over coming weeks will dismantle Elizabeth and bring her to the surface of the Cherrybrook site in pieces.

TBM1 was named after colonial pioneer Elizabeth Rouse.