Fire in Notre Dame in Paris

[dimreepr]

 

 

1

5 hours ago, John Cuthber said:

interested to see the suggestions that it should be rebuilt with modern materials- at least in part for safety reasons.

As far as I can tell, the important thing about old buildings is that they are OLD buildings. If you replaced the cathedral with a modern titanium clad skyscraper you wouldn't have Notre Dame any more.

if it looks like a duck

[Airbrush]

17 minutes ago, John Cuthber said:

Nobody had.

Next time...have one.

[zapatos]

8 minutes ago, Airbrush said:

Next time...have one.

How much water will this helicopter hold?

[Airbrush]

20 minutes ago, zapatos said:

How much water will this helicopter hold?

Good question.  Some water is better than none.  What is the ideal quantity of water to allow QUICK pickup from the river, using an average chopper and also be effective? 

Or if Paris can afford it have a big, tanker chopper that can service all the ancient buildings in Paris.

My next question is, where could they have installed an INTERIOR sprinkler system?  That could have stopped the fire sooner.  I heard the fire started high up near the roof so most sprinkler systems would not have stopped it.  You need sprinklers as high up as you can install them.

Edited April 19, 2019 by Airbrush

[zapatos]

Since the fire started IN the building I'm wondering what a couple hundred gallons of water on the roof will accomplish. And once the roof is burning I'm wondering if a couple hundred gallons makes flying directly over the fire worth the risk. Who makes water-dropping helicopters? I've not seen them before.

[John Cuthber]

43 minutes ago, Airbrush said:

Next time...have one.

OK

[Makes note in diary for the year 2819]

 

 

 

 

[iNow]

2 hours ago, zapatos said:

Who makes water-dropping helicopters? I've not seen them before.

They’re pretty commonly used in California to treat wildfires. 

[zapatos]

11 minutes ago, iNow said:

They’re pretty commonly used in California to treat wildfires. 

Thanks. 

Edit: Up to 2600 gallons per bucket. Impressive.

Edited April 19, 2019 by zapatos

[Enthalpy]

17 hours ago, zapatos said:

How much water will this helicopter hold?

Used elsewhere too. A medium-sized helicopter can transport 1-2t, essentially water in this case. They often carry the water bag under a long line, to fly well above the flames.

The Seine is less than 100m away from Notre-Dame and half a dozen heliports exist around Paris. If several helicopters and pilots can operate the water bag, then the helicopters might perhaps be commercial ones - or not.

The difficulties I imagine:
- It was not planned. This can't be improvised.
- Overflying Paris is forbidden.
- What targets? Monuments don't burn every year. Whether a chopper is good for bureaus and houses? An idle helicopter costs more over 800 years than a roof (yes, I know - but you got the idea).

17 hours ago, zapatos said:

Since the fire started IN the building I'm wondering what a couple hundred gallons of water on the roof will accomplish. [...]

The beams burnt between the stone ceiling and the lead roofing. The roofing melted quickly away, leaving the beams exposed to falling water. When only 100t wood were burning, 10t water would have extinguished them with limited overweight on the building. This would have saved the spire and the stone ceiling below.

Maybe a helicopter to fight fires in buildings could have a water jet if the recoil is moderate. The bag opened at once is meant against forest fires, where a strong impact is desired. Then you have the drawback of fanning the flames; could it be alleviated by flying higher and downwind?

18 hours ago, Airbrush said:

[...] where could they have installed an INTERIOR sprinkler system?  That could have stopped the fire sooner.  I heard the fire started high up near the roof so most sprinkler systems would not have stopped it.  You need sprinklers as high up as you can install them.

Sound reasonable to put the sprinklers targeting the wooden structure rather than the stones.

I see no reason why they should only douse downwards. I understand the oldest ones have an opening that melts under heat and operate at low pressure from a tank above, whose weight may have been excessive for the old building. But presently the system could be more active and detect flames from a distance or smoke to spurt water upwards from a tank on the ground.

Or the firefighters could have trucks whose jet reaches tall buildings. Rather not a free jet as it fans apart, but a long articulated stiff pipe similar to concrete pumps. It needs no-one at the top, only cameras and a remote control. The long arm must be strong and the truck stable.

[John Cuthber]

Once in 800 years or so, the sprinkler saves the building.

How often does it go off by accident and destroy priceless artifacts?

[swansont]

26 minutes ago, John Cuthber said:

Once in 800 years or so, the sprinkler saves the building.

How often does it go off by accident and destroy priceless artifacts?

Or destroy the artifacts that could have been saved, even if there was a fire.

_____

Lots of places use dry agent fire protection (e.g. FM 200), in enclosed spaces with sensitive contents, but typically you’re willing to sacrifice the structure to protect the contents.

[Airbrush]

8 hours ago, Enthalpy said:

Or the firefighters could have trucks whose jet reaches tall buildings. Rather not a free jet as it fans apart, but a long articulated stiff pipe similar to concrete pumps. It needs no-one at the top, only cameras and a remote control. The long arm must be strong and the truck stable.

I like your idea of a "long articulated stiff pipe" so the helicopter can inject water with pinpoint accuracy, away from the rotor wash.  The chopper may also have a drilling device to open a hole in the roof to inject the water (or dry flame retardant) using the long water pipe.

Edited April 20, 2019 by Airbrush

[Enthalpy]

Thinking more at the firefighter helicopter resulted in a hexacopter to improve the pointing freedom of the jet. Description of one sized to fit in a lorry, there:
https://www.scienceforums.net/topic/75102-electric-helicopter/?do=findComment&comment=1102008

On 4/20/2019 at 1:45 PM, John Cuthber said:

Once in 800 years or so, the sprinkler saves the building.
How often does it go off by accident and destroy priceless artifacts?

I'd say it's the same interrogation for non-historical buildings, whose answer is "yes" to sprinklers despite they may spurt without reason. But that is a good argument for fully passive sprinklers opened by heat rather that electronics, or worse, software.

In the particular case of Notre-Dame's roof, there was nothing more apparently. A stone ceiling isolates it below, which avoided more fire damages. But I understand that water damage would be a concern in different buildings.

Edited April 21, 2019 by Enthalpy

[DrP]

On ‎4‎/‎18‎/‎2019 at 8:51 PM, Airbrush said:

Yes, but old buildings can always be retro-fitted with safety devices.  Why don't they build an ornate tower that is actually a swiveling HOSE, controllable by joystick and camera monitors, that can reach the entire structure?  Any ancient structure can have such a firefighting structure retro-fit, that is hardly noticeable, but blends into the exterior design.  

Do old buildings in the US all have these fitted then or something? 

[Carrock]

1 hour ago, DrP said:

On 4/18/2019 at 8:51 PM, Airbrush said:

Yes, but old buildings can always be retro-fitted with safety devices.  Why don't they build an ornate tower that is actually a swiveling HOSE, controllable by joystick and camera monitors, that can reach the entire structure?  Any ancient structure can have such a firefighting structure retro-fit, that is hardly noticeable, but blends into the exterior design.   

Do old buildings in the US all have these fitted then or something? 

All the old US buildings have these fitted.

They're not considered cost effective for modern buildings i.e. less than 500 years old.

[DrP]

Just now, Carrock said:

All the old US buildings have these fitted.

They're not considered cost effective for modern buildings i.e. less than 500 years old.

OK thanks. I think they might be an USA thing then - I've not heard of them over here in the EU.  I work in 'Passive' Fire protection, so wouldn't necessarily know about the system anyway as it is active, but would have thought I would know more about it if it was common here.

 

 

 

 

[swansont]

8 minutes ago, Carrock said:

All the old US buildings have these fitted.

They're not considered cost effective for modern buildings i.e. less than 500 years old.

By that metric, all buildings in the US are modern buildings.

I was under the impression that (in the US) as building codes are modified, they are only applied to new construction, or when you remodel old construction.

[DrP]

Just now, swansont said:

By that metric, all buildings in the US are modern buildings

6 minutes ago, Carrock said:

They're not considered cost effective for modern buildings i.e. less than 500 years old.

 

ha ha - yea - I've just realised, lol.  ARE there any buildings older than 500 years old in your country even? 

[swansont]

Just now, DrP said:

 

ha ha - yea - I've just realised, lol.  ARE there any buildings older than 500 years old in your country even? 

Perhaps an odd structure here an there, built by the native Americans, but nothing by European settlers. To us, "old" means "colonial" (250-300 years old). It's a culture shock to go to Europe, where you are regularly seeing buildings and walls that are 3 times as old, and a few things that are much older.

[michel123456]

FYI some idea of what was there before destruction by fire. It is in French but the pictures are speaking for itself.

http://hermetism.free.fr/Viollet-le-duc_architecte.htm

The peak of the roof (the "arrow" or "fleche") was not soo old, it had been rebuild by the renowned architect Eugene Viollet-le-Duc in 1859, with conductor of works Georges. I am afraid there are no many "Georges" available today to redo the work. It was a wooden structure coverted with lead. Not a stone in it. It covered the stone structure that was below the base of the roof.  to be noted that the wooden roof did not even touch the stone vaults. The roof stands directly on the pillars. See section here.

If the Fleche had not collapsed, the stone vaults would have stopped the fire (as they did for most of the building) because there is no connection between the building rooms & the void of the roof: you have to go up to a terrace outside & enter the roof through a small door.

Edited April 23, 2019 by michel123456

[swansont]

Since a related topic had come up

 

[dimreepr]

 

 

 

5 hours ago, swansont said:

Perhaps an odd structure here an there, built by the native Americans, but nothing by European settlers.

Lucky you... 

 

 

 

5 hours ago, swansont said:

To us, "old" means "colonial" (250-300 years old). It's a culture shock to go to Europe, where you are regularly seeing buildings and walls that are 3 times as old, and a few things that are much older

To us, it's a burden...

[Janus]

5 hours ago, swansont said:

By that metric, all buildings in the US are modern buildings.

I was under the impression that (in the US) as building codes are modified, they are only applied to new construction, or when you remodel old construction.

Or in some cases, when a building is taken out of service and then returned to service.   This occurred in a local school district.  Due to a decline in student numbers, it was decided to close an older outlying elementary school.    However, against the chance that they might, in the future, need to reopen it,  they still used a couple of classrooms for Alternative School.   As long as some part of the building was being used as a school, they could, if needed, just reopen the entire school.  But if they stopped using it as a school entirely, they would have had to bring the building up to modern code before they could reopen it again.  ( As it was, student numbers continued to fall, and they eventually sold the building and property).

[swansont]

(for some reason I am unable to quote dimreepr)

 

I am currently mired in the joy of dealing with "historic" buildings as part of a construction project. We have two buildings which are >50 years old and ugly as sin, but since they are old enough to be "historic" they will have to be handled in a certain way when they are refurbished — limited options on any exterior improvements we might make. (Their historical ugliness must be preserved, apparently) It's a royal PITA.

If we had a deeper history, there might not be the same emphasis on preserving these relatively new buildings.

[koti]

1 minute ago, swansont said:

(for some reason I am unable to quote dimreepr)

I can’t quote him on iphone on iOS 12.2 with Safari. Windows 10 with Chrome same thing.