By Lynda Myer
In order to constructing the next 11km section of Sydney Metro West, two TBMs have been recommissioned.
Being relaunched from Five Dock Metro Station site, TBMs Beatrice and Daphne have the responsibility of building the new metro tunnels from The Bays to Sydney Olympic Park, whereas their next stop is due to be 2km away at the future Burwood North Metro Station site.
The two machines made tunneling history in December last year when they arrived at Five Dock Station site minutes apart to achieve the first double TBM breakthrough in the southern hemisphere.
Also, following the 10 weeks time for traversing the 200m-long station cavern at Five Dock, they had undergone maintenance, including the replacement of gear boxes and cutter discs.
With 165m length, each double shield hard rock TBM weighs 1,300 tons and has 34 rock-cutting discs in its 7m diameter cutterhead and their average progress will be 200m per week, while are estimated to complete their journey by the end of the year.
Although currently the TBMs have left Five Dock, work is slated to continue to prepare the 30m-deep cavern for station construction, and the relaunch marks the commence of a significant year of tunneling for the 24km-long twin-bore Sydney Metro West.
Making good advance in building the tunnels between Sydney Olympic Park and Westmead, autonomous TBMs Betty and Dorothy are more than 1.3km and 930m into their journey, respectively.
In the future months for constructing the metro tunnels beneath Darling Harbour further two TBMs will arrive at The Bays and tunneling will start mid-year.
The scheduled date for completion of Sydney Metro West is 2032 and after inauguration it will double rail capacity between Greater Parramatta and the Sydney CBD.
