Question on air raid siren near Dublin airport

Muahahaha

Just wondering if any spotters or pilots know the reasons behind an air raid tyoe siren that goes off approx 2am in the vincinity of Dublin Airport? I think it might be the Roadstone plant below the flight path from the Finglas end of the runway. It might not be Roadstone but it seems to be coming form somewhere that area. I haven't heard it in a couple of months now but at some times of the year it can be a nightly event.

Also while I'm here- if a plane takes off going from east to west (ie from Ballymun towards Blanch what can a layman like myself assume about the wind direction? i.e do planes take off into the prevailing wind or away from it?

Reoil

Can't help about the noise, but if the plane is taking off east to west, then the wind is going west to east or thereabouts.

Yeah it's blasting at Huntstown Quarry, used to hear it myself the odd time.

Davy

Muahahaha wrote: »

Just wondering if any spotters or pilots know the reasons behind an air raid tyoe siren that goes off approx 2am in the vincinity of Dublin Airport? it?

Didn't think they would be blasting at 2am

billie1b

If you're residing close enough or have a business close enough they get a list time of all the explosions on the site.
They've fubared up a couple of them, few business' around have had windows damaged and cars

Muahahaha

Davy wrote: »

Didn't think they would be blasting at 2am

Me neither but the Roadstone plant has lights on throughout the night so I'm assuming its a 24 hour operation.

Im thinking the reason for the 2am blasts might be because they are using dynamite beneath a flight path ? I never hear the actual blasting myself but I always hear the siren. As I said it hasnt been used in a couple of months now but i would expect it back at some stage

FWVT

Has this been occurring during these cold nights? If so then it's probably just due to the fact that the sound is travelling much further as it becomes ducted under the temperature inversion that forms as the air near to the ground is several degrees cooler than the air tens of metres up. That's also why you can hear traffic from a distant busy road much better on a frosty morning.

Tenger

Davy wrote: »

Didn't think they would be blasting at 2am

Could it be safer to do so...less staff about on night shift in case the controlled explosion goes awry?

OzCam

Controlled explosions don't go awry. That's what the firer is paid for.

And if they're done right you will hardly notice them. It's all right to shatter half of a mountainside in the middle of the Outback or the MidWest, but closer to, er, civilisation, some subtlety is required.

Still have to give plenty of loud warnings though.

PukkaStukka

Many moons ago (back in the good old days of RWY23!) I used to live not too far from where Sillogue golf course / Harristown Bus depot is now. Roadstone had a small plant in or around this spot, and every Sunday morning exactly at 7:30am , I used to hear a sound like a WW2 air-raid siren go off. I've no idea what it was for or why it went off, but it definetly came from that place. There was no quarry there either so no blasting. One unproven theory we had was that it could have been something to do with the cleaning of a cement cyclone on site which may have generated a lot of dust, and the siren was obviously an audible warning in advance of this.

Tabnabs

OzCam wrote: »

Controlled explosions don't go awry. That's what the firer is paid for.

And if they're done right you will hardly notice them. It's all right to shatter half of a mountainside in the middle of the Outback or the MidWest, but closer to, er, civilisation, some subtlety is required.

Still have to give plenty of loud warnings though.

Tell that to the crew that blasted the M50 junction at Dundrum. A barely audible siren followed by a crackling, smashing sound running through the ground for a couple of miles all round. Went on for weeks.

OzCam

Tabnabs wrote: »

Tell that to the crew that blasted the M50 junction at Dundrum. A barely audible siren followed by a crackling, smashing sound running through the ground for a couple of miles all round. Went on for weeks.

They should have been using low-order stuff then. It's a science, but it's a bit of an art as well. In the glory days of the Celtic Tiger doing things quietly was downright unpatriotic.

The ground vibration might also have been caused by drilling the shafts for the charges. That takes much longer than the actual firing.

crosstownk

I work in Swords and I also regularly hear this 'air raid siren'. Usually in the afternoon. I've often wondered what it's for.

Muahahaha

crosstownk wrote: »

I work in Swords and I also regularly hear this 'air raid siren'. Usually in the afternoon. I've often wondered what it's for.

Now you mention it I have heard it the odd afternoon too. But I've mainly heard it approx 2am, though not in the last few months but before last October it was an almost nightly event it seemed.
It must be the Roadstone quarry, it makes the most sense of whats around the area, as for the 2am sounding of the siren I've no ideas. It's likely against noise pollution laws, I'm surprised the residents along the old N2 havent complained about it as I'm about 2 miles from it and can hear it clearly when it does sound, people closer must get woken up by it.

crosstownk

A lad in work reckons it's from the RNLI building in Airside. I work quite close to the RNLI building so maybe that's the siren I'm hearing. We may be talking about 2 different sirens. The one I hear is the classic wartime movie air raid siren.

andy_g

crosstownk wrote: »

A lad in work reckons it's from the RNLI building in Airside. I work quite close to the RNLI building so maybe that's the siren I'm hearing. We may be talking about 2 different sirens. The one I hear is the classic wartime movie air raid siren.

RNLI building does have a siren for when they are using wind and rain at the pool facility but thats about it. And it sounds a a lil bit different