34L pavement failure!
 

Just saw this on ATIS:

Anyone know more details? Sounds rather dramatic!

After the rain we've had, and now the sun hitting it, the pavement weak spots get exposed and voila, we have a failure! The public roads will be no different, but you probably won't really notice them as they blend into the other failures. Pot holes or delamination can form and jetblast scatters the debris. Obviously the loose stone (or chunks of it) and resulting hole aren't exactly ideal for aircraft operations.

I'm actually amazed the closure of 34L we did on Sunday for a pavement failure didn't get reported here...
There's also been at least a dozen small failures in the past 3 or 4 days which have either required closure or restrictions to facilitate temporary repairs. The curfew period gives the opportunity to put more permanent repairs in place.

Thanks for the info, Nigel - where is the 34L pavement failure today?

Possibly on Sunday we were all out spotting and no-one was watching ATIS until after the runway was re-opened? By the way, do you guys have ATIS gear in your ground vehicles?

No idea...back on shift tonight.

We have VHF radio for ground/tower ATC and company UHF (digitally encrypted I think). I presume that's what you meant?

Looks like the bluetack is working again:

I thought the runways were made from some pretty hardcore type concrete and were extremely thick. How does a pothole form in solid concrete? And how does one repair a pothole in cement? You can't just fill it with ashphalt right?

All the runways at Sydney are predominantly asphalt, with some concrete areas like the 16L, 16R, 25 and 07 runway ends (34R and 34L are asphalt). Yes, the asphalt is very thick, and deep asphalt repairs can be ~17cm deep (these take ages to cool sufficiently, so generally not preferred unless the cause of the failure is also deep). A typical asphalt repair is around 10cm deep.

Although concrete is strong, if it develops issues and needs major repair, the time required to rip the bad stuff up, pour the new stuff and then allow for cure time can be well over a month. It wouldn't be ideal if the failure occurred in the middle of the runway.

The concrete doesn't pothole, but if the concrete is old or weak or the slab moves the edges can crack causing a FOD problem. To repair cracking or bad edges in concrete, a product called Everek is used. Factsheet can be found here http://www.cticonsultants.com.au/CTI%20Everek%20SRE.pdf

Asphalt typically isn't used to fill in holes in concrete, as it doesn't bind well with the concrete.

I should add, Rwy 34L is due for a resheet soon. There'll be some loooong nights ahead....

The failure was pretty much at the intersection of 07/25. There was also one near A3 that was fixed at the same time.

Luckily the failure was discovered during a quieter time in the early afternoon, so it wasn't too busy. A couple of smaller aircraft had to do some figures for 34R (a B767 to RPLL and a Cairns flight I think) and United from ML landed on 34R (don't see that too often), but other than that there were no other major issues.

On another note, might be time to get Polair out there again with lasers reported SW of the field :(

Also seems to be a few bats around as well.

Bat crap is pretty corrosive on car duco...maybe it's eating holes in the pavement too....:p;)

Nigel,

They can resheet the entire length of 34L in one or two nights? and have it ready for ops the next day?

One or two nights??? 45m wide x ~4km long??? No chance!!!!:eek:

Ignoring the need to replace the lighting (runway edge and taxiway lead-out lighting), the first night is typically just profiling or milling the surface layer of the asphalt for maybe a couple of hundred metres. There might be some paving or laying of new asphalt, but the paving crew can only go as far as the milled section. Any painted markings removed by the profiler must be replaced by the end of the night.

Each night after that the paving crew will lay the new surface over the stuff that was milled the night before, and the profilers (3 at a time) will prepare the surface for the next night. They might lay 250-300m of new asphalt in a night, using up to 3 'shuttle buggies' connected to 3 pavers (+1 on site usually as a spare). Again, all painted markings must be replaced.

The runway has to be serviceable for the first arrival, so all debris has to be removed. There might be 3 or 4 street sweepers operating at the same time.

Total time for just resheeting the runway might be 2-3 weeks without any rain delay, but then there's the lighting to be reinstated and that can take possibly months to completely restore. Grooving the runway takes place ~6 weeks after the new asphalt has gone down, and that's a loooong sloooow process.:(
The available reduced length runway configurations the freighters require during curfew may also dictate what days the work can be restricted to, so the process could be dragged out a fair bit longer.

I hope this helps.



Pictures added in case you're not familiar with the jargon...
Profiler
http://www.hmegerian.com/images/machinary/large/0.jpg
Paver
http://www.forconstructionpros.com/a...8_PRE17743.jpg
Shuttle Buggy
http://www.qpave.com.au/images/SB1500.jpg

More work on 34L?
 

I see that 34L is being taken out of action again early this afternoon for departures - is that connected with last night's work?

Will the restriction to 34R disrupt any schedules for a/c that need more available takeoff length or can't perform the tight right turn after takeoff (or will they be allowed to overfly the City)?

Nigel, love the info thanks!

How often do the runways require resheeting?

Thankfully not very often! Maybe once every 10 years for a full resheet, longer if the pavement holds up.