Article: Airport Link tunnelling work hits rail line

[ozbob]

From the Courier Mail click here!

Airport Link tunnelling work hits rail line

Airport Link tunnelling work hits rail line

   * Ursula Heger
   * From: The Courier-Mail
   * April 16, 2010 9:49PM

TRAINS have had to be diverted in Brisbane's north after tracks on the line subsided because of construction on the $4.8 billion Airport Link project.

Queensland Rail confirmed yesterday tracks on the Toombul line had sunk a number of times over previous months, as Airport Link teams install 48 canopy tubes under the railway lines.

The tubes are used as ground support to ensure the tracks remain operational when tunnelling begins underneath the rail line later this year.

When subsidence occurs on a track, which is monitored by a QR civil track observer, trains have had to be diverted to one of three other tracks.

At one point a section of track subsided about 30mm before trains were diverted to other tracks and the problem rectified.

A QR spokesman said there was no danger to passengers and no trains had been delayed or cancelled because of the work.

He said the subsidence had to be filled before trains could return to the track.

"When minor subsidence occurs, due to train movements or other activity, crushed rock is pushed under the rail line to fill any gaps, and a heavy machine known as a tamper is used to pummel the rock back into place," he said.

"In relation to Airport Link, any significant subsidence recorded will be rectified prior to trains running over the affected section of track."

While QR was responsible for fixing the track subsidence, the companies behind Airport Link are billed for the cost.

It is the first time in Australia that a road tunnel on the scale of the Airport Link project has been installed under an operational rail line.

When the tunnel is complete there will be 6m between the rail line and the top of the tunnel structure.

If there were delays, no doubt TransLink would be out there fining QR Passenger in its nonsensical manner ...

[Golliwog]

Thats more than likely true. Hopefully though, if they did, QR would just pass these fines onto the Airport Link project.

[Derwan]

Yep - the article mentions that Airport Link is billed for the work.

My blog comment:  This was pretty obvious.  At times trains have slowed at this location (caution in place due to subsidence).  Trains heading north on Down Main (the western-most track) lean to the left as they go through this section.

[ButFli]

This is a little bit unsettling.

QR have a "civil track worker" on site to monitor the situation. What about subsidence that is happening in other places, presumably unmonitored? What happens when the land under someone's house subsides by 30mm or more? Does it go unnoticed, unrectified and uncompenstated?