Construction on the new Sydney Metro line has reached new heights with the completion of one of its most complex sections.
For the past month, a team of 30 workers has carefully constructed a two-span section of elevated viaduct over the two pipelines responsible for transferring 80 per cent of Sydney’s water from Warragamba Dam to filtration plants for treatment.
Working closely with WaterNSW, the project team took on the highly technical task during the winter months when water demand is at its lowest. This allowed for one pipe at a time to be depressurised, a process which essentially deactivates the pipe, to allow for work to safely be carried out above.
A total of 26 segments, each weighing up to 65 tonnes were installed up to 15.3 metres above the pipelines.
A significant amount of preparation was required to strengthen the ground around the pipelines, while rigorous vibration and settlement monitoring was implemented throughout construction activities to ensure the pipelines remained unaffected.
Central to the strategy for protecting the integrity of the pipelines was the use of the underslung temporary beam, a purpose-built crane used to snugly support the segments while they were lifted and positioned, eliminating any risk to the pipelines below.
Reaching this stage in construction means the team is now on the home stretch to complete the 3.5km of elevated viaduct between Orchard Hills and Luddenham.
More than 18 per cent of the viaduct remains to be built, with production of all 1,101 concrete segments at a facility just outside Newcastle now complete. The final 208 segments will be installed over the coming months.
Each segment along the viaduct measures 10.85m in width, up to 3.2m in length, and stands at 2.4m in height. A total of 52,000 tonnes of concrete was used to cast the segments.
The impressive viaduct structure is a critical part of the alignment and has been implemented to take metro services over key locations including the Warragamba pipelines, Blaxland Creek, and Luddenham Road.
Major tunnelling to build the 9.8-kilometres of twin tunnels that take the metro line underground between Orchard Hills and St Marys in the north and Airport Business Park and Bradfield in the south was completed in June 2024.
By the end of the year, the majority of the viaduct and sections of the alignment at ground level will be finished, making way for the commencement of tracklaying.
This new Sydney Metro railway will become the transport spine for Greater Western Sydney, connecting communities and travellers with the new Western Sydney International (Nancy-Bird Walton) Airport and the growing region.
Image: Sydney Metro
