Tunnel boring machine (TBM) Jane Starkey successfully completed her 1.2km underground journey through challenging Sydney sandstone.
The breakthrough was a milestone in the Thornleigh Inlet/Outlet Pipeline Duplication Project, signalling a bold step forward in efforts to strengthen Sydney’s drinking water infrastructure.
The challenges were not just physical but contextual. Working within constrained urban environments called for traffic management, noise and vibration mitigation, and careful planning to ensure that utilities, homes, and natural features remain undisturbed. Above all, ensuring the safety of communities and workers was paramount – a goal achieved through painstaking planning and adherence to best practice in tunnelling safety protocols.
This complex duplication project, led by Sydney Water in partnership with the Ironbark Joint Venture – a collaboration between Rob Carr and Bouygues Construction Australia – is part of a strategic investment to enhance the resilience of Sydney’s water network. The pipeline being installed runs parallel to the existing main between Thornleigh Reservoir and the Thornleigh-Wahroonga Water Pumping Station, vital infrastructure that supplies drinking water to growing communities.
By creating a second, parallel pipeline, Sydney Water is safeguarding against disruptions and enhancing the network’s capacity to serve northern Sydney as populations rise. Growth projections for the region are significant, and infrastructure like this ensures that essential services keep pace with demand.