By Rose Bell
Considering that on the city-shaping Sydney Metro – Western Sydney Airport project, all major tunneling is officially complete, currently Greater Western Sydney hosts new 9.8-kilometre twin metro railway tunnels.
Following that the tunnel boring machine (TBM) Marlene arrived at the St Marys Metro Station site achieving the final tunnel breakthrough on the project, this historic landmark was reached, whereas the tunnels are slated to become the transport spine of the Greater West.
Through digging 1,863,460 tonnes of material, that is enough to fill 300 Olympic pools, and installing 69,966 concrete segments to line the new tunnel walls, the TBMs constructed two separate sets of tunnels at either end of the alignment during 14 months.
In order to reaching St Marys, the 4.3-kilometre tunnels from Orchard Hills, beneath the M4 Motorway and the Great Western Highway were bored by TBMs Marlene and Catherine, while construction of the 5.5-kilometre tunnels from Airport Business Park, underneath the new Western Sydney International Airport, to Aerotropolis was up to TBMs Eileen and Peggy.
The final TBM breakthroughs achieved as follows:
- TBM Catherine completed the first tunnel at the St Marys site on 20 May 2024.
- TBM Eileen broke through at the Aerotropolis site on 29 May.
- TBM Peggy made the penultimate breakthrough for the project and arrived at the Aerotropolis site on 7 June.
- TBM Marlene made the final breakthrough at the St Marys site on 20 June 2024.
Once tunneling completed, the TBMs are due to be dismantled, cleaned moved to a storage location, before they are shipped back to the Herrenknecht.
Including completion of the construction of 39 cross passages and preparing for tracklaying to begin, work inside the tunnels will continue.
