Sydney Metro has completed the 9.8-kilometre twin metro railway tunnels for the Sydney Metro – Western Sydney Airport project.
This milestone was celebrated as tunnel boring machine (TBM) Marlene reached St Marys Metro Station, marking the final breakthrough in the tunnelling phase of the project.
Over the course of 14 months, four TBMs—Marlene, Catherine, Eileen, and Peggy—excavated a combined total of 1,863,460 tonnes of material, enough to fill 300 Olympic-sized swimming pools. They also installed 69,966 concrete segments to line the tunnels.
TBMs Marlene and Catherine completed the 4.3-kilometre tunnels from Orchard Hills to St Marys, passing beneath the M4 Motorway and the Great Western Highway.
In addition, TBMs Eileen and Peggy constructed the 5.5-kilometre tunnels from the Airport Business Park, under the new Western Sydney International Airport, to Aerotropolis.
The final breakthroughs were achieved as follows:
- 20 May 2024: TBM Catherine completed the first tunnel at St Marys
- 29 May 2024: TBM Eileen broke through at Aerotropolis
- 7 June 2024: TBM Peggy made the penultimate breakthrough at Aerotropolis
- 20 June 2024: TBM Marlene completed the final breakthrough at St Marys
With the tunnelling phase concluded, the TBMs will be dismantled, cleaned, and transported to a storage facility before being shipped back to their manufacturer.
Construction efforts will now focus on completing 39 cross passages within the tunnels and preparing the infrastructure for track laying.
