SydneyMetroWest TunnelBoringMachine ParramattaInfrastructure InfrastructureAustralia

Sydney Metro West Marks Tunnelling Milestone at Parramatta Station

*TBM Dorothy breaking through into the Parramatta station box after months of continuous tunnelling. Source: Tunnels and Tunnelling*

The Sydney Metro West project reached a major tunnelling milestone with the arrival of tunnel-boring machine (TBM) Dorothy at the Parramatta station box. After a 17-month journey through solid sandstone, Dorothy’s arrival follows TBM Betty, which already advanced toward Westmead. The two machines have collectively excavated over 1.25 million tonnes of material since early 2024. The breakthrough follows a six-week delay caused by concerns over a nearby building's foundation.

The Sydney Metro West project will deliver a 24-kilometre twin tunnel system connecting Sydney Olympic Park to Parramatta, with 90% of tunnelling now completed. The TBMs have installed over 48,000 precast concrete segments to line the tunnels. Each segment weighs up to 4 tonnes, contributing to a reinforced structure designed for long-term reliability and safety.

Installing Pre-Cast Segments. Source: Snapshot of 7News Australia Video

Six of nine station boxes have been excavated and lined. Work continues at key nodes including Parramatta, Pyrmont, and Hunter Street. Once operational, the metro is expected to enable a 20-minute trip between Sydney’s west and CBD. The Parramatta station will serve as the core of a mixed-use precinct, linking with Light Rail and the Civic Link pedestrian corridor.

Check out the following video discussing the milestone achievement and project characteristics.