A SECOND tunnel-boring machine has begun tunnelling at High Wycombe as part of the $1.86 billion Forrestfield-Airport Link project.
Sandy – named after the WA sandgroper by local student Sarah Spratt – was launched today from the 12m-deep dive structure at the site of the future Forrestfield train station.
Sandy’s ‘sister’ machine Grace – named after schoolgirl Grace McPhee – was launched in July, starting a two-year journey to Bayswater where the 8.5km Forrestfield-Airport Link will spur off the Midland rail line.
Grace began tunnelling in August, and has now travelled more than 600m in to the earth at a speed of 20m per day.
The two machines will each tunnel 8km under Perth Airport and the Swan River, linking new stations at Forrestfield, Airport Central and Belmont.
Construction of diaphragm walls (which will house the station box structure) is now complete at Airport Central, and excavation of the soil inside the walls has begun.
Diaphragm walls are also under construction at Belmont, and are about 70 per cent complete.
As the machines’ cutter heads bore through the earth, the machines will also install about 54,000 reinforced concrete tunnel segments.
About 5750 segments of the 54,000 needed to complete the tunnel structure have already been fabricated at a Forrestfield facility.
“From now on, as the construction of the three train stations on the Forrestfield-Airport Link ticks on above ground, underneath the surface Grace and Sandy will be boring and reinforcing the foundation of the tunnels which trains will run through in only three years time,” Transport Minister Rita Saffioti said.
Federal Urban Infrastructure Minister Paul Fletcher said the new Metronet line would provide a 20-minute link between the eastern foothills and the CBD – as well as the wider public transport network – via the airport.
“About 2000 jobs will be created as part of the project,” he said.
“Grace is expected to break into the station box at Airport Central station in early 2018, with Sandy following shortly after.”