TBMs Jessie and Ruby have passed the point 35m below the water’s surface on their second drive across the harbour. They previously travelled below Sydney Harbour at Johnstons Bay.
Each TBM now has less than 700m of tunnel left to build to reach their final destination at the future Hunter Street metro station in the heart of the Sydney CBD.
To construct the 250m tunnels below Darling Harbour, the TBMs travelled from the Australian Maritime Museum on the western shore towards King Street Wharf on the east.
The TBMs will next tunnel beneath some of Sydney’s busiest and best-known streets, including York, George and Pitt streets and pass closely underneath Wynyard Station to reach the Hunter Street cavern.
This part of the journey will require precision tunnelling as the TBMs dig close to existing critical infrastructure including the City East Cable Tunnel, a 132KV underground cable responsible for powering the CBD.
TBMs Ruby and Jessie have excavated about 286,692 tonnes of earth so far and have about 7,000 precast tunnel segments to install to reach Hunter Street.
The mix shield TBMs are progressing at a steady pace of around 90m per week. They are on track to reach the Hunter Street site by the end of this year.
While TBM Jessie and Ruby were specifically built for this project, some components are refurbished. Parts for both machines came from the TBMs used to construct the Sydney Metro City & Southwest tunnels including part of the main drive, transformers, control cabinet, erector and switch cabinets.
In July this year the two TBMs made a double breakthrough at the Pyrmont metro station cavern.
Tunnelling for Sydney Metro West began in early 2023 and has reached 97% completion for the 24km line connecting Westmead to the Sydney CBD. The new line, which is scheduled to open in 2032, will provide a 20-minute connection between the Sydney CBD and Parramatta.
Once Sydney Metro West opens, passengers will have fast, high-frequency metro services connecting the Sydney CBD with Parramatta in a 20-minute trip – doubling rail capacity between those two centres.
