A third tunnel boring machine (TBM) has finished work on the Sydney Metro Northwest tunnels, which are now 97% complete.
TBM Elizabeth arrived at the Cherrybrook site in New South Wales for a rare night-time breakthrough, ending her role in delivering the twin 15km metro tunnels from Bella Vista to Epping. In total, the machine drilled 9km from Bella Vista to Cherrybrook.
Elizabeth was the first TBM to start digging on Australia’s largest public transport project in September 2014 and was in the ground four months ahead of schedule. The TBM will now be dismantled and brought to the surface at Cherrybrook in a series of operations expected to last several weeks.
More than 29km of the 30km tunnelling task is now complete. The only remaining TBM, named Florence, has approximately 850m left to dig and is also on its way to Cherrybrook.
Sydney Metro Northwest, the first stage of the Sydney Metro project, will be the first fully-automated metro rail system in Australia.
Sydney Metro Northwest is expected to be operational in the first half of 2019.
During her 15-month journey, TBM Elizabeth:
- Excavated more than 700,000t 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 cutterhead 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 171m