Tunnelling at Forrestfield, the site that hosts the infrastructure vital to tunnel boring machine (TBM) operations, began in August (TBM Grace) and October (TBM Sandy) 2017. The site is operating 24 hours a day to support tunnelling activities, including processing excavated soil and treating water for reuse in the tunnelling process.
Within the station area installation of hydraulic, electrical and fire protection services for the station platform has been completed and a number of platform slabs has been poured. Eight steel columns for the suspended concourse slab were delivered to site and are scheduled to be installed in April. The suspended slab, to be located above the station’s platform, will form an extension of the concourse slab.
At concourse level several concrete pours have been completed for the station’s 130m-long concourse slab. To allow for the slab’s sixth pour to take place, three 4m-wide and 8m-tall tilt-up panels were added to the station's retaining wall late-March. These will allow for additional backfilling to occur. The slab is expected to be finalised by the end of April, by which time a total of 300 cubic metres of concrete will have been poured.
South of the station the stowage building is now fully enclosed following the installation of eight temporary doors, the roof and gutters. Fitout of the building is ongoing. The stowage area is the place where trains will be maintained whilst not in use.
At the portal end of the site, and just above the tunnel entries, brickwork for the multi-storey portal building is being finalised at plant level. In the coming weeks structural steel will be installed, taking construction up to mezzanine level.