Sydney Metro West tunnel borers dig deep under Darling Harbour

Once Sydney Metro West opens, passengers will have 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.

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 now has less than 700 metres 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 250-metre tunnels below Darling Harbour, the TBMs travelled from the Australian Maritime Museum on the western shore toward 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 central business district.

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 TBMs are progressing at a steady pace of around 90 metres per week, working around the clock with the assistance of a dedicated tunnelling team of 210 workers.

The tunnelling machines are on track to reach the Hunter Street site by the end of this year.

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-kilometre line connecting Westmead to the Sydney CBD.

Sydney Metro West is targeting an opening date of 2032, with transformational travel times of:

· Hunter Street to Parramatta in 20 minutes

· Hunter Street to Sydney Olympic Park in 15 minutes

· Five Dock to Parramatta in 12 minutes

· Pyrmont to Hunter Street in 2 minutes

More than 5.87 million tonnes of earth will be excavated to build the Sydney Metro West tunnels, equivalent to filling 1,500 Olympic-sized swimming pools.