Sydney Metro – Western Sydney Airport project tunnelling now complete after final breakthrough

The Sydney Metro – Western Sydney Airport project has reached a milestone with the completion of the 9.8-kilometre twin metro railway tunnels. These tunnels, crossing underneath Greater Western Sydney, will serve as the transport backbone for the region.

This achievement was marked by the tunnel boring machine (TBM) Marlene’s arrival at the St Marys Metro Station site. Over 14 months, the project’s four TBMs excavated 1,863,460 tonnes of material, enough to fill 298 Olympic pools, and installed 69,966 concrete segments to line the tunnels.

Marlene and Catherine constructed the 4.3-kilometre tunnels from Orchard Hills to St Marys, passing under the M4 Motorway and the Great Western Highway. They broke through on 21 June and 20 May 2024. Eileen and Peggy built the 5.5-kilometre tunnels from Airport Business Park to Bradfield, underneath the new Western Sydney International Airport. These breakthroughs were on 29 May and 7 June 2024.

With the tunnelling phase complete, the TBMs are being dismantled, cleaned and transported away on trucks back to the manufacturer.