In late July 2017, TBM Grace set off from Forrestfield to Bayswater, building one of two tunnels that will house the $1.86 billion project’s rail lines.
Half of the 54,000 locally fabricated concrete segments – used to form the walls of the twin tunnels – were installed during Grace’s journey, with her route taking her under Perth Airport and the Swan River and through diverse ground conditions.
On the way she passed through Airport Central and Redcliffe Station boxes, large structures in their own right.
TBM Grace will now be dismantled and craned out of the dive structure in preparation for the arrival of TBM Sandy, who is a safe distance behind Grace and is expected to finish tunneling in May.
Trains are set to run on the new rail line in the second half of 2021, providing a 20-minute rail link between the eastern foothills, Perth Airport and the Perth central business district.
“This is a huge milestone for METRONET and the end of a very long journey for TBM Grace,” Premier Mark McGowan said. “Where once there was dirt, sand, rocks and tree roots, now sits the foundation for our new railway. Completing the Forrestfield-Airport Link is a key part of our METRONET plan to connect Perth’s suburbs and ease congestion.”
“This is a proud moment for WA workers, who have just finished the longest rail tunnel ever attempted in WA history,” Transport Minister Rita Saffioti said. “We started tunneling on the Forrestfield-Airport Link project in late July 2017 and we now eagerly anticipate the safe arrival of TBM Sandy in coming months to mark the completion of tunneling.
“With the end of tunneling in sight, work is continuing on important infrastructure components such as station construction and fit out and readying the tunnels for track laying. The precision engineering it has taken for this machine to tunnel 8 km, through varying and sometimes challenging soil types, to break through in exactly the right spot is truly remarkable.
“METRONET is the biggest public transport project Perth has ever seen and will provide a fast and easy transport connection between Perth’s suburbs.”
The project was built by a Salini Impregilo-led JV with NRW Pty Ltd to build two 8-km twin-bore tunnels, three stations, three emergency egress shafts and parking spaces. The tunnels are 7-m excavated diameter driven by two specially designed TBMs from Herrenknecht.