TBM Grace breakthrough at Forrestfield’s Airport Central Station

TBM Grace broke through into the underground station box at Forrestfield’s Airport Central Station, travelling 1.9 km and installing 1188 rings. This is the first time the TBM has ‘surfaced’ since beginning tunnelling at Forrestfield nine months ago. The TBM will continue to advance into the station box in coming weeks whilst undergoing maintenance.
Also, the project’s second TBM, Sandy, is due to arrive at Airport Central Station later this month. TBM Sandy has so far travelled 1.8 km and installed 1121 rings.
Under the project, a significant milestone has been reached at Bayswater Junction with the completion of all 133 diaphragm wall (d-wall) panels for the tunnel portal and dive structure. The final d-wall was poured in the first week of May and marks the completion of d-wall construction across the entire project. Attention will now turn to excavation of the 400m-long dive structure and tunnel portal, where trains will enter and exit the Forrestfield Line tunnels.
Excavation within the Redcliffe Station box is expected to be completed, more than 42,000m3 (97 per cent) of spoil being removed to date. With Redcliffe Station the next stop for TBMs on their 8-km journey to Bayswater, works will turn to the pouring of concrete for the base slab of the underground station box. Construction of the base slab is expected to begin next week and will continue until late August. After completion, dewatering at the site will be turned off.
In April 2016 Salini Impregilo-NRW Joint Venture (SI-NRW) were awarded the $1.176 billion contract for design, construction and a ten year maintenance period once the project is complete in 2020.
The USD 1.4 billion Forrestfield-Airport Link will deliver a new rail service to the eastern suburbs of Perth – with three new stations at Redcliffe, Airport Central and Forrestfield.
In April 2016 Salini Impregilo-NRW Joint Venture (SI-NRW) were awarded the AUD 1.176 billion (USD 883 million) contract for design, construction and a 10-year maintenance period once the project is complete in 2020.
By 2021 the line is expected to generate 20,000 passenger trips on the network every day, increasing to 29,000 daily by 2031.