Ruby launches into action to build final Metro West tunnel under Sydney Harbour

Launching from The Bays, TBM Ruby will join TBM Jessie in constructing 2.3-kilometre twin railway tunnels that will take metro deep below the harbour, this time creating another key connection into the heart of the city for people living in Sydney’s west.

TBM Ruby is named after women’s rights activist and Australia’s first radio astronomer Ruby Payne-Scott and is the sixth and final TBM to get to work on building the 24-kilometre Metro West tunnels.

The 1,100-tonne machine will operate around the clock, seven days a week. It will slowly inch its way alongside the iconic Anzac Bridge, through the Pyrmont Station site, and under Darling Harbour, before arriving at its final destination at Hunter Street in the Sydney CBD.

TBM Jessie is hard at work on the parallel tunnel and has excavated 615 metres and installed 2,238 concrete segments to line the new tunnel walls since commencing its tunnelling journey in June.

A total of 460,000 tonnes of material will be excavated and 16,536 segments will be installed by the two TBMs to construct the tunnels between The Bays and Hunter Street.

Transport Jo Haylen said the sixth and final Tunnel Boring Machine is now on her way as the government builds the game-changing Metro West project.

“TBM Ruby will dig a highly complex section of tunnel, carving its way beside the Anzac Bridge, below two sections of the harbour and finishing in the centre of the Sydney CBD,” she said.

“Over the next 20 years, 420,000 people are expected to move into the corridor surrounding this these future Metro stations. This new line will keep our growing city moving.”

These tunnels will form the second under-harbour railway crossing for Sydney, with the first built between the city’s north and Barangaroo for the metro M1 line, which has recorded 82 million journeys since opening on 19 August.

TBMs Ruby and Jessie are heading towards Pyrmont Crossover and Station caverns, where they will traverse the station cavern before being relaunched towards Hunter Street Station.

TBMs Ruby and Jessie are mixed shield (slurry) machines, specifically designed for the Metro West project to excavate in the highly pressurised conditions that are anticipated under Sydney Harbour.

Parts of both TBMs came from the TBMs used to construct the Sydney Metro City & Southwest tunnels.

The TBMs are expected to arrive at Hunter Street in mid-late 2025.

Sydney Metro tunnelling partners John Holland CPB Contractors Ghella Joint Venture are excavating the under-harbour tunnels and two new station caverns at Pyrmont and Hunter Street as part of the Sydney Metro West – Eastern Tunnelling Package.

Major tunnelling is progressing across the alignment, with two TBMs completing the 11-kilometre tunnels from The Bays to Sydney Olympic Park, and a further two TBMs in the ground to build the nine-kilometre tunnels between Sydney Olympic Park and Westmead.

Sydney Metro West will double rail capacity between Greater Parramatta and the Sydney CBD. It will make it easier and faster to travel around western Sydney, link new communities to rail services and support employment growth and housing supply.