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February 6, 2026 — 5:00am
Cocktails might be flowing readily at Sydney’s King Street Wharf and other central city bars this summer, but revellers should spare a thought for Jessie.
Named after suffragette and Indigenous rights campaigner Jessie Street, the giant tunnelling machine and the workers directing her have been slogging it out metres beneath partygoers’ feet.
She has struck unexpectedly hard rock in the last few hundred metres as she struggles to complete one of two tunnels for Sydney’s largest underground metro rail line, delaying her arrival at the finish line by about two months.
When she set off in mid-2024, Jessie was the first of two 1100-tonne boring machines to begin tunnelling the final 2.3 kilometres of the $29 billion Metro West rail line.
Despite starting later, her fellow boring machine, Ruby, broke through into a giant cavern beneath Hunter Street in the city on December 17, delivering an early Christmas present for workers by completing one of two concrete-lined tunnels from a station site at The Bays precinct in Rozelle.
Jessie has been moving much more slowly than anticipated, due to challenging ground conditions beneath King Street Wharf and other parts of the central city, raising the likelihood that she will not reach the eastern end of the line until late February or early March.
The slog to the finish line illustrates the complexity of tunnelling and the potential to strike unexpectedly tough ground conditions. The 130-metre-long boring machines have already navigated a fault line and foundations for the Anzac Bridge on their journey eastwards.
Known as mixed-shield slurry machines, Jessie and Ruby were specifically designed to deal with the risk of soft soils and water ingress while digging under the harbour, making them different from the four other tunnel borers that have carved out other sections of the line.
Sydney Metro said Jessie was slowly progressing through hard sandstone and “very difficult conditions” but was now under Kent Street in the central city. “The rock conditions have been more challenging than [those] encountered by [boring machine] Ruby,” the agency said.
The rock material Jessie is churning through is turned into a semi-liquid mixture and pumped back to a treatment plant at The Bays, where excavated material is removed. Clean slurry is then recirculated back to the face of the boring machines.
Jessie is set to become the last boring machine to carve out rail tunnels in Sydney for a long time, unless the Minns government has a sudden change of heart and decides to fund a new pipeline of multibillion-dollar underground metro train lines.
The government confirmed in December that the cost of Metro West will blow out by as much as $3.7 billion to $29 billion. A major contributor has been the skyrocketing cost of stations.
The 24-kilometre Metro West line between Westmead and the central city is due to open in 2032.
Testing required to complete the final stage of the M1 metro line in Sydney’s south-west will result in the full closure of the existing 51.5-kilometre section from Tallawong to Sydenham via the central city on the weekends of February 21-22, March 7-8 and 21-22.
The final stage between Sydenham and Bankstown was to be opened in late 2025 after a 12-month shutdown of the old heavy rail line, but was later delayed until the second half of this year.
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