After several months of intensive work, the projects to duplicate a major drinking water pipeline in Thornleigh (TIOM) and a wastewater pipeline in Rouse Hill (MNW) are now entering their final phase.Operations in TBM Tunnelling: BESSAC deploys an Innovative Solution for Safer and More Efficient Tunnel Projects
Delivered for Sydney Water by the Ironbark Joint Venture, the project brings together Bouygues Construction Australia, Rob Carr Pty Ltd, and BESSAC, which has contributed its technical expertise, specialized equipment, and dedicated teams to carry out the shaft and microtunnelling works.
MNW: Connection Works Near Completion
At the two Sydney Water facilities, the wastewater treatment plant and the pumping station, the operations to connect the new pipelines to the existing infrastructure have now been successfully completed.
At the same time, the project has moved into its second phase, focused on upgrading Sydney Water’s existing facilities and integrating new equipment. This stage will deliver long-term improvements in network performance and reliability.
TIOM: A Major Milestone Successfully Achieved
On the TIOM project, activity has reached its peak over recent months. The civil engineering structures required for the connections, including the connection chambers linking the existing pipeline, the pumping station, and the drinking water reservoir, have now been completed.
Since July, the project teams have been engaged in one of the most complex phases of the project: connecting the new pipeline to the existing network. These operations require planned shutdowns of the current pipeline, which supplies drinking water to several thousand residents.
The project has also achieved a major technical milestone with the successful hydrostatic pressure test of the microtunnel at 17.5 bar. This achievement reflects a significant collective effort, including:
- 1,164 metres of microtunnel constructed using reinforced concrete pipes with a steel cylinder lining;
- 313 welds completed inside the tunnel to join the pipes at the steel liner level;
- 313 internal joint coatings applied over the welds inside the tunnel to ensure the long-term durability of the structure.
The successful completion of this test marks the end of all tunnelling activities within the Sydney Water TIOM & MNW program. It represents a major achievement for the project teams, which are now focused on the final connection and commissioning works ahead of the delivery of the completed infrastructure.
