News Articles | 26 July 2018

In another exciting project milestone, both TBMs have now left Airport Central Station to tunnel the 2.8km towards Redcliffe Station.


After undergoing a detailed maintenance program, the machines will install a combined 3291 rings before breaking through into the underground station box at Redcliffe later this year.

With the tunnels now fully formed between Forrestfield and Airport Central stations, works are progressing on construction of the project’s cross passages. These passages will be located approximately every 400m along the alignment, and will provide a safe connection between the tunnels. At our 23m deep emergency egress shaft off Abernethy Road, the first cross passage between the tunnels has now been excavated.

‘Excellent’ sustainability rating for project

At the recent Infrastructure Sustainability Council of Australia state conference the project was awarded an ‘excellent’ rating for its commitment to delivering an innovative and sustainable transport solution for Western Australians.

Embedding integrated sustainability principles in our design, procurement and construction processes has been paramount for the project. This means that all individuals and companies involved in the project are committed to developing and building the asset in the most sustainable way possible. Practices include:

  • Minimising water consumption and use of potable water

  • Minimising energy use and production of greenhouse gases, including use of solar power

  • Sustainable sourcing of materials

  • Implementing at least three State-first innovations

Roadwork near completion at Forrestfield site

The Dundas Road realignment is on track to open in August, with drainage pits being installed and intersection works due to be completed over the coming weeks. Once open, the currently divided Forrestfield construction site (dive structure to the west and TBM operations infrastructure to the east of Dundas Road) will be joined. View a map of the changes to Dundas Road. 

All wall panels for the southern retaining wall of the future station are now in place and backfilling is continuing to raise the ground level at the station by up to 6m.

Work is continuing south of the site with the installation of services for the stowage yard. The stowage yard will be the end of the Forrestfield Line, where trains will be cleaned and maintenance will be undertaken.

Infrastructure focus at Airport Central Station

With both TBMs having left Airport Central Station, and following the removal of the sacrificial segments used to guide the TBMs through the station box, the focus is back on the development of site infrastructure.

In-ground services such as fire, water, sewer and storm water have been installed, tested and backfilled around the station.

Footings to support the elevated walkway which will connect the station with the terminals have been completed, enabling further ground slab works.

The station is starting to take shape with recommencement of construction of the oval-shaped columns between concourse and ground levels, along with the construction of stair walls within the station box.  

Concreting in and around Redcliffe Station

Construction of Redcliffe Station is progressing well, with the station box excavated and waterproofing now being installed. Upcoming works will focus on constructing the station’s base slab with nine separate concrete pours of a 1.5m depth each.

Additional jet grouting will be required for the cross passage at Brearley Avenue. Cross passages are located along the 8km route to allow entry/exit from one tunnel to the other. They are constructed using the jet grouting process, a construction technique used to improve ground conditions and stabilise soils in preparation for tunnelling works.

Micro-tunnelling completed in Bayswater 

Our mini-TBM has now completed tunnelling for the main drain relocation, and activity over the next few weeks will include open cut pipe laying, construction of inlet and outlet structures, earthworks for the new upstream channels and rehabilitation. The temporary closure of a 50m wide section of Whatley Crescent, between Anzac and Newton streets, will remain in place until mid-August.

At the dive structure, installation of the struts and walers is underway to support the diaphragm walls during excavation of the tunnel portal and dive structure. Further along the dive structure, adjacent to Whatley Crescent, three of the four concrete pours to construct the cross over for the Midland Line have been completed. The city-bound train will travel over the dive structure on the 100m long overpass bridge before merging with the Forrestfield Line, before Bayswater Station. 

Connecting our emergency egress shafts

Cross passage connections have now been excavated to link our first emergency egress shaft (EES), off Abernethy Road, to both tunnels. The construction team is now preparing to install the waterproofing membrane and permanent concrete between the tunnel and the emergency egress shaft to finalise these works.

At our second EES excavation has now finished after reaching a final depth of 35m below ground level. Works will shift to construction of the base slab for the shaft, before this EES is also connected to the tunnels.

With the completion of jet grouting and core drilling at the third EES site, near Wright Crescent, works to construct the capping beam are underway. Excavation of the shaft can then begin.

To find out more about these structures, view the emergency egress shaft fact sheet.

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