The route for the Forrestfield-Airport Link includes 8km of twin-bored tunnels, with safe entry and exit points via underground stations at Redcliffe and Airport Central, as well as tunnel portals at Bayswater and Forrestfield.
Given the length of the tunnels, additional infrastructure is required between the stations to allow safe egress to the ground level in the event of an emergency, and access to the tunnels for maintenance.
As such, three emergency egress shafts (EES), twelve tunnel-to-tunnel cross passages and three tunnel-to-egress shaft cross passages will be constructed along the alignment.
View the cross passage and emergency egress shaft construction fact sheet.
View a map of all cross passage and emergency egress shaft locations.
Emergency Egress Shafts
What is an emergency egress shaft?
An EES provides access from the tunnels to ground level via stairs and lifts.
Its layout is designed in conjunction with the Department of Fire and Emergency Services to ensure functionality during an emergency situation.
It takes up to six months to build each EES and another six months to build the supporting ground level infrastructure (a two-storey portal building, car park and emergency muster point).
The portal buildings house communications, electrical and mechanical equipment and controls. They also contain air vents which will help ventilate the shafts and tunnels.
All three emergency egress shafts are fully excavated, and the respective base slabs have been poured.
Abernethy Road EES is awaiting construction of the staircase, lift shaft and ancillary building, all due to commence mid-year.
Outside the 39m-deep emergency egress shaft at Wright Crescent, the construction of the ground slab is ongoing. The installation of conduits for services such as power, water and firefighting systems are now complete.
What is a cross passage?
A cross passage is a short concrete tunnel which provides a link between two main tunnels, or a link between a tunnel and an EES. It takes up to three months to build each cross passage, which are up to 10 metres long and five metres high (around three metres high after final lining installation).
At Airport West EES excavation has been completed between the shaft and Tunnel One. Excavation of the cross passage to Tunnel Two will commence once TBM Sandy's 130m-long trailing gantries have cleared the area.
Both the tunnel-to-tunnel cross passage at Dundas Road and the cross passages between Abernethy Road EES and the tunnels have been completed.
Waterproofing of the project’s second tunnel-to-tunnel cross passage, Cross Passage RAC, is now complete. After the waterproofing membrane was installed, steel reinforcement was placed ready for the next layer of concrete to be sprayed on using a remote controlled robotic concrete machine.
Over the coming weeks, once works at Cross Passage RAC are complete, the construction team will move to Cross Passage Car Park C to begin the excavation process.
Meanwhile, set-up works for ground freezing for the three cross passages located underneath Perth Airport's airside environment has now commenced.