A bit of a non story on FAL from today’s The West Australian...

A bit of a non story on  FAL from today’s The West Australian except that it points the finger at private enterprise (the airport)  for causing delays to the project which were perhaps unnecessary .
It also notes airport concerned will be laid to rest once the second TBM is off airport property early in January .
https://thewest.com.au/business/inf...field-airport-rail-link-tunnel-ng-b881048508z


“Airport fears helped stop work on Forrestfield-Airport rail link tunnel

Daniel MercerThe West Australian
Monday, 17 December 2018 2:01AM

Perth Airport engaged international experts on tunnelling and helped prompt a halt to work on the Forrestfield-Airport rail link over concerns two boring machines were a risk to the airport’s infrastructure.

The private owners of the airport moved to protect their assets after problems emerged with the tunnelling work for the trouble-plagued $1.8 billion rail line, including a sinkhole in the middle of the airport’s estate.

With Transport Minister Rita Saffioti under pressure to reveal the extent to which the link’s 2020 deadline will be delayed, the airport’s misgivings are the latest sign of stress on a project that is the first stage of Labor’s flagship Metronet policy.

Tunnelling consultants were brought in as a precaution before work on the link began, but it is understood Perth Airport contracted “world experts” to provide further advice when the project was hit with technical setbacks.

In February, tunnelling had to be stopped for more than a month after one of the two boring machines, Grace, triggered sinkholes just 300m from the site of the planned airport train station.

Work was again brought to a standstill in September when tunnelling precipitated an even worse ground disturbance alongside Dundas Road on the eastern perimeter of the airport’s estate.

The airport said the FAL was a Public Transport Authority project, declining to say whether it intervened to call a halt to work at any time during the tunnelling process.

It stressed that at no stage did the tunnelling affect critical infrastructure including the airport’s runways or taxiways, while pointing out that both boring machines had either moved outside the airfield or were about to do so.

But The West Australian understands the privately owned corporation was instrumental in forcing head contractor Salini Impregilo-NRW to suspend operations after it expressed concerns about the risks of the tunnelling work.

“There have been no ground disturbance issues with (or damage to) either the main or cross runway,” an airport spokesman said.

“One tunnelling machine has now exited the airfield, with the other currently estimated to follow early January. Expectations are both machines will reach Redcliffe station (off the airport estate) by around mid-March, but this should be confirmed with the PTA.

“As previously advised, as part of the PTA project plan an extensive network of ground monitoring equipment was installed to mitigate the risks associated with tunnelling as the boring machines pass under the airport estate, including the runways.

“The PTA has responsibility for the FAL project and Perth Airport has worked co-operatively with the PTA on issues related to tunnelling under the airport estate.

“Perth Airport retained the services of both domestic and international technical experts to assist in the interpretation of data relating to the project.”