foggybottom
Venator imaginum
You still have cordless phones?!?!
Boy have I got a deal for you. 
I'll replace your batteries for a buck $2.98 + parts, shipping, tax and FCC fees. You can keep the old batteries I don't have a core charge. 
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Notre-Dame ...
- Thread starter messaline
- Start date
You still have cordless phones?!?!
Boy have I got a deal for you. I'll replace your batteries for a buck $2.98 + parts, shipping, tax and FCC fees. You can keep the old batteries I don't have a core charge. 
old slave
FELIS RESPICIENS
For large industrial uses, Europe taps into the full 450V 3-phase, we use one of those phases for the 230V domestic supply.
I recently toured a nearly completed building. There was a maze of yellow wires, jointed into multiple big transformer/fuse boxes, for the builders' temporary supply for lights and outlets. Then there was the fixed installation in various stages of completion, from bare-ended dangling wires to working circuits. A small error in understanding or paperwork would easily lead to a short. This was a new-build. Imagine doing this in an old building where electrical circuits from the dawn of time to yesterday have been installed, old ones disconnected but probably not all wires carefuly removed.
Fire investigators are clever people, but cannot work miracles if the evidence is completely destroyed by either the fire itself or the collapsing timbers and stone vaulting.
We will wait, but we may never know.
Well, I'm not sure that all these explanations could bring us to the " 7th sky " ...
Whoa!
foggybottom
Venator imaginum
I can agree that large industrial systems would use the higher voltage, we use 460 V 3 phase to run plants here and the 150 HP motors I mentioned would be 460 V. But I would have thought the temporary installation would not require the full high voltage for elevators, etc. Then again, it's like a fellow I used to work with was fond of saying " Ahh, there you go again....thinking!" and I don't really know European procedures. Also you are correct about the new installation having dangling bare wires on uncompleted circuits, standard modus operadi. I've wired up a few panels myself. Safety regulations are strict in the US all technicians working on a particular line place lockout boxes on the supply of the circuit and if you do not follow the regulations you are terminated. The individual circuits are wired to the breakers on the equipment end 1st, tested and then the power side is wired in and unlocked. It looks scary to the average lay person but all wires are color coded and numbered and no power is on bare wires. The hi-vis yellow cables are temporary extension lines necessary for portable equipment, all finished lines must be in metallic conduit. But "to err is human."
Old buildings here in the US have some borderline wiring also, old wiring not completely removed and I've seen ancient turn of the century (earlly1900s) "knob and tube" wiring still in use.
As old as Notre Dame is hard telling what was done in past years. Our fire investigators are amazingly efficient here as well and can pretty well determine where and what started a fire even from the condition of the ashes. We'll have faith and hopefully the reconstruction will get under way quickly. At this point I'll stop all the conjecture lest I make a total fool of myself. 
Loxuru
Graf von Kreuzigung
Considering how air crash investigators sometimes single out that one piece of metal with an abberant damage pattern, out of ten thousands of debris, and start reconstructing the disaster from that information, I think a cause could emerge for Notre Dame too.
cruxlover
Tribune
Then again the fire at Windsor Castle which occurred during restoration work was due to a powerful work light being left "On" overnight.
From the illustrations of Notre Dame that I have seen, there seems to be a void space above the vaulted stone ceiling and below the lead-covered timber roof. How visible would this area be to the security/watchpersons (if any) after the workforce had left site?
From the illustrations of Notre Dame that I have seen, there seems to be a void space above the vaulted stone ceiling and below the lead-covered timber roof. How visible would this area be to the security/watchpersons (if any) after the workforce had left site?
It might be of interest - though clearly it's not the same as Notre Dame -
to note what caused the two fires that between them
almost completely destroyed Glasgow's most 'iconic' building,
the Mackintosh Building of the School of Art:
2014
The fire at Glasgow School of Art’s historic Mackintosh building in May was started when flammable gases from a foam canister used in a student project were ignited, according to a report by the Scottish fire and rescue service.
The category-A listed building was engulfed in flames as students were preparing for their final-year degree show. Much of their work was lost, along with the building’s famous library, one of the world’s finest examples of art nouveau design, which housed many rare and archival materials as well as original furniture and fittings.
The report concludes that the blaze began when a projector ignited gases from the expanding foam and took hold quickly as gaps in the walls. Old ventilation ducts assisted its spread into neighbouring studios and upwards through the building.
The student work in question was made up of foam panels fastened to three walls, with one wall left blank to receive images from a projector. At the time of the incident, visible gaps between the panels were being filled by applying expanding foam from a canister.
2018
It is understood that as part of the rebuilding project after the first fire at the Mackintosh building, all the timber in the wood-panelled library was being treated with linseed oil.
The oil must be treated with caution because when it combines with air, the oxygen molecules cause a chemical reaction that creates heat. Experiments have shown that it can spontaneously catch fire if stored in the wrong conditions. Rags soaked with linseed oil, especially when stored in a restricted space where heat cannot dissipate, are a known fire hazard.
to note what caused the two fires that between them
almost completely destroyed Glasgow's most 'iconic' building,
the Mackintosh Building of the School of Art:
2014
The fire at Glasgow School of Art’s historic Mackintosh building in May was started when flammable gases from a foam canister used in a student project were ignited, according to a report by the Scottish fire and rescue service.
The category-A listed building was engulfed in flames as students were preparing for their final-year degree show. Much of their work was lost, along with the building’s famous library, one of the world’s finest examples of art nouveau design, which housed many rare and archival materials as well as original furniture and fittings.
The report concludes that the blaze began when a projector ignited gases from the expanding foam and took hold quickly as gaps in the walls. Old ventilation ducts assisted its spread into neighbouring studios and upwards through the building.
The student work in question was made up of foam panels fastened to three walls, with one wall left blank to receive images from a projector. At the time of the incident, visible gaps between the panels were being filled by applying expanding foam from a canister.
2018
It is understood that as part of the rebuilding project after the first fire at the Mackintosh building, all the timber in the wood-panelled library was being treated with linseed oil.
The oil must be treated with caution because when it combines with air, the oxygen molecules cause a chemical reaction that creates heat. Experiments have shown that it can spontaneously catch fire if stored in the wrong conditions. Rags soaked with linseed oil, especially when stored in a restricted space where heat cannot dissipate, are a known fire hazard.
malins
Stumbling Seeker
Another example would be the Anna Amalia Library in Weimar ... a much younger and smaller building than Notre Dame, it's from the late 1600's
At the turn of the 21st century curators decided there wasn't enough room for manuscripts and reading / research rooms, and the library was no longer a safe place for the existing volumes
... so a renovation and extension was started in 2002, planned to take 2-3 years...
... towards the end of it, in 2004, the library burnt down... with the loss of many unique volumes
... the fire started in the roof construction ...
... it's assumed the cause was electrical although it was never precisely determined.
It seems ironic that many such buildings stood and safeguarded their contents, for centuries, and then succumbed to modern improvement efforts.
The problem is of course that they were slowly decaying, and it was the fear that this would cause catastrophe, that prompted the renovations.
We can't just assume they would have stood forever if nothing had been done ...
... and any change ever done, comes with some risk.
There will just have to be even more care taken in the future.
Anyway, what with the international competition for the roof/spire replacement, we are seeing some more of what the modern architectural profession is up to ... this from Norman Foster, no surprise...
... see also https://archpaper.com/2019/04/foster-partners-pitches-notre-dame-spire-competition/
Gibbs505
SERVORUM DOMITOR
Actually, apart from the spire, that's not such a bad idea!
messaline
Crucified Amazon
Excepted that a library is made to read , so, the light is welcome ...
But a cathedral is made for the prayers and the meditation , so, a dark space seems more appropriated for that ...
And more, if you bring too much light indoor , you'll see less the stained glasses : they were conceived to create a contrast
permitting the best view of that they are depicting ( like in a cinema for example ) ...
Attachments
Gibbs505
SERVORUM DOMITOR
Good point. I only said that it wasn't a bad idea!
cruxlover
Tribune
Notre Dame seems to have an arched stone ceiling (which appears to be mainly intact, apart from where the spire wrecked it) so the glass roof would only let light into the space between ceiling and roof. Besides the space under that glass roof become a hothouse in summer.
Another impractical flight of fancy, like the glass bridge with no visible means of support (held up by the Fairies?), or handrails, that Architects proposed for Bedford's new footbridge. An unlovely steel lattice bridge, more suited for a motorway than the town centre, has actually been built.
foggybottom
Venator imaginum
The latest from a US news site on Notre Dame fire, more guessing. 
http://news.trust.org/item/20190424184708-qxte6
http://news.trust.org/item/20190424184708-qxte6
cruxlover
Tribune
And -- everyone says "Not me Guv".The latest from a US news site on Notre Dame fire, more guessing.
http://news.trust.org/item/20190424184708-qxte6
Naraku
Draconarius
Let the finger pointing and denials begin.
Frank Petrexa
Tribune
More on glass bridges. Native Americans make money from something other than casinos on the mostly marginal land on their reservations. People trust chemical engineers to make glass and civil engineers to use it. America is built on faith and entrepreneurship. What could go wrong? (If something does go wrong, it is also the land of lawyers.)
https://en.wikipedia.org/wiki/Grand_Canyon_Skywalk
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cruxlover
Tribune
If something goes wrong there - it would be too late to sue.
I think I will stick to the tree-top walk at Kew Gardens (mind you even that height could be fatal.)
Mind you an English guy who devised one of the first retractible covers for HGV tipper trucks did so after a mate was killed by falling when sheeting his load.
Crux-Emperor Baracus X
Rectidolor
If they fail in the task.....crucify them. !!
Frank Petrexa
Tribune
If something goes wrong there - it would be too late to sue.
I think I will stick to the tree-top walk at Kew Gardens (mind you even that height could be fatal.)
Mind you an English guy who devised one of the first retractible covers for HGV tipper trucks did so after a mate was killed by falling when sheeting his load.
In the US, it's never too late to sue. Before Hewlett-Packard broke up, when it was discovered that it had paid way too much for a software firm it acquired (according to the company, the owners had cooked the books) and had to take a massive write-down, it was sued by a law firm on behalf of the shareholders for malfeasance and poor management. The settlement specified that the company would address its "governance" issues and pay reparations. Coincidentally, the "reparations" were just enough to cover the law firm's fee. The shareholders got nothing.