Author Topic: Notra-Dame  (Read 273 times)

Offline Fire Monkey

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Notra-Dame
« on: April 15, 2019, 08:50:22 PM »
So sad.

I will double my efforts if I ever do another FRA at a church.

Offline John Webb

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Re: Notra-Dame
« Reply #1 on: April 16, 2019, 08:53:26 PM »
It would seem once again a "heritage" building has suffered during works in progress, alas!

There is much in a number of peoples' books about 'Hot Work Permits' and regular site checks at intervals after such work has been completed. I've yet to see anyone suggesting that hand-held IR cameras might be used to enhance such checks. Has anybody any knowledge if this has been tried out?

Fire Monkey: Thanks for your promise; I've been dealing with the outcome of a serious fire at a church in Royston - only goes back in part to 1250, so not quite as old as Notre Dame, but never-the-less the local community there has been greatly upset.
John Webb
Consultant on Fire Safety, Diocese of St Albans
(Views expressed are my own)

Offline Messy

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Re: Notra-Dame
« Reply #2 on: April 17, 2019, 04:03:57 AM »
Maybe all future cathedrals should be made out of scaffolding as the scaffold structure over what appears to be the area of origin of this fire behaved particularly well ::). Despite hours of intense fire beneath, it didn't seem to collapse which is pretty remarkable

Offline lyledunn

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Re: Notra-Dame
« Reply #3 on: April 17, 2019, 07:27:58 AM »
Due to the lattice construction and the ties to the building the load on the scaffold was probably displaced such that it was negligible. It might have been hot up there but it would have been well ventilated.
I am working on a couple of large refurb projects at the moment, it is not hard to see how fires could start through sheer carelessness.

Offline Messy

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Re: Notra-Dame
« Reply #4 on: April 17, 2019, 05:26:25 PM »
The scaffold was almost definitely either steel or aluminium

Steel softens at 425C and loses half its strength around 650C
Ali loses half its strength a little earlier at 600C

With timbers having auto ignition temperatures of around 460C and the sheer loading and flame height, surely the scaffolding would have been capable of reaching temperatures not far short of those values?

Maybe the scaffolders simply over-engineered it to provide 100%+ structural safety margin!?

Hands up who has projects on the go in large iconic buildings where there is hot work at height and the job considerable complex scaffolding around and over it

That would be me for one!! :o :o :o

Offline Fishy

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Re: Notra-Dame
« Reply #5 on: April 18, 2019, 07:21:12 AM »
For most buildings, the time when they are most exposed to fire risk is when they are having building work done on them.  Fire detection and alarm / fire suppression systems isolated; compartmentation temporarily breached; means of escape altered; temporary and altered wiring; uncontrolled build-up of combustibles; hot works... the list goes on.  If this does prove to be a fire started by construction works, then in our own part of the world the Windsor Castle fire; Glasgow school of art etc, etc. are all precursors.

The risk is to life can be substantial if they remain partially occupied during the works, & in many cases the FRAs aren't reviewed to take this into account.  I've just done a FRA for a part-occupied construction site and found fire exits chained shut, 100m+ dead ends formed in an occupied space, to name but a few issues.  The client and the contractors both have to take responsibility for managing these risks (the client can't really just leave it all up to the contractor and view it as their risk).

When I'm reviewing these types of premises, I always keep in mind that these are construction works.   Whilst the construction industry is getting better, I keep in the back of my mind what I once heard from a surveyor colleague (a long time ago, but there's still an element of truth in it):  "...what you've got to remember about the construction industry is that it's full of the guys who p***ed about at school, managed by guys who also p***ed about at school, wearing ties....  Things have changed now of course. 

They don't tend to wear ties any more.

« Last Edit: April 18, 2019, 07:36:41 AM by Fishy »

Offline Fishy

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Re: Notra-Dame
« Reply #6 on: April 18, 2019, 01:36:43 PM »
Maybe all future cathedrals should be made out of scaffolding as the scaffold structure over what appears to be the area of origin of this fire behaved particularly well ::). Despite hours of intense fire beneath, it didn't seem to collapse which is pretty remarkable

No, it didn't collapse completely, but the aerial footage shows it sagging impressively into the aperture that the spire once sat over.  It will have been plenty hot enough to do this in the fire plume.