TBMs Jessie and Ruby have passed the deepest point below Darling Harbour, located about 35-m beneath the water’s surface, as they continue to carve out the Sydney Metro West line that once opened will allow to passengers fast, high-frequency and reliable metro services connecting the Sydney CBD with Parramatta in a 20-minute trip - doubling the rail capacity between those two centres. To construct the 250-m tunnels below Darling Harbour, the TBMs travelled from the Australian Maritime Museum on the western shore toward King Street Wharf on the east.
This is the second dive under the harbour for Jessie and Ruby since starting their journey from The Bays last year – previously they travelled below Sydney Harbour at Johnstons Bay.
Each TBM has less 700 m of tunnel left to build to reach the future Hunter Street metro station in the heart of the Sydney CBD, their final destination. The machines will 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 central business district.
TBMs Ruby and Jessie have excavated about 286,692 t of earth so far and have about 7,000 precast tunnel segments to install to reach Hunter Street by the end of this year. More than 5.87 million tonnes of earth will be excavated to build the Sydney Metro West tunnels.
TBMs Ruby and Jessie are progressing at a steady pace of around 90 m per week, working around the clock with the assistance of a dedicated tunnelling team of 210 workers.
Jessie and Ruby are specialty TBMs designed to dig under high-pressure conditions beneath Sydney Harbour. They move at a slower pace than traditional TBMs because of the wetter conditions and geological environment they are required to navigate.
While TBMs Jessie and Ruby were specifically built for this project, some components are refurbished. Parts for both TBMs 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.
Tunnelling for Sydney Metro West has been underway since early 2023 and has reached 97 per cent completion for the 24-km line connecting Westmead to the Sydney CBD. Sydney Metro West is targeting an opening date of 2032.
For further information click here and au/11 for tunnelbuilder archive. Visit https://www.sydneymetro.info. 47/25.
