Twin towers fireproofing questioned

Boston Globe ^ | 5/8/03 | Sara Kugler

[RJCogburn]

Fireproofing on the steel floor supports in the World Trade Center was never tested and may have been too thin to hold up in a fire for the two-hour minimum set by the city building code, federal investigators said yesterday. The north tower fell about an hour and 45 minutes after terrorists attacked with the first hijacked jetliner on Sept. 11, 2001. The south tower collapsed about an hour after it was struck. Nearly 2,800 people were killed.

[Mr. Bird]

From everything I've read, introducing jet fuel into the equation renders regular fire retardant tests moot. I have wondered if "officials" tried to contact the buildings' architects and engineers immediately to assess the possibility of collapse. It wouldn't have saved those trapped, but they might not have sent in the firemen, or pulled them back quicker...

[Broker]

Had the steel beams been coated with ASBESTOS, we would not be discussing this subject. Obviously, substitute material is inferior.

!!!!!!! More people died on 9/11 from no asbestos than those who inhaled it!!!!!!!!!!!!!!!!!!

Thank the trial lawyers..........

[HamiltonJay]

This is CRAP! The plane slamming into the building ripped the coating from substructures anywhow!!! Those buildings fell because 19 agents of hell decided to commit a heinous act of barbarism.. To try to blame 911 on anything else is insane! Any lawyer making this argument should be tarred and feathered and then disemboweled!

[cyborg]

Yep.

[OXENinFLA]

From everything I've read, introducing jet fuel into the equation renders regular fire retardant tests moot.

That's what I 1st thought when I saw this on the news last night.

[Ingtar]

There was a special on one of the Cable channels not long after 911. They showed the effect of any missing fire retardant. They also brought up the fact that the retardant was being replaced, as what was used to replace the asbestos was peeling off. The new standard would have protected from a fire, but with the damage done by the plane, it was amazing that the buildings remained up as long as they did.

[theDentist]

As I recall, during the building of the structures (somewhere around the 40th floor) an injunction was obtained forbidding the use of asbestos and xome other retardents because of the fear of cancer. So the very people who fought to safeguard the live of occupants in fact endangered their lives even moreso. I doubt that with the original retardants the structures would have stayed up, but they may have stood a bit longer. I guess that's just conjecture.

[beelzepug]

Not a bad plan for lawyers in general.

[Wonder Warthog]

"As I recall, during the building of the structures (somewhere around the 40th floor) an injunction was obtained forbidding the use of asbestos and xome other retardents because of the fear of cancer. So the very people who fought to safeguard the live of occupants in fact endangered their lives even moreso. I doubt that with the original retardants the structures would have stayed up, but they may have stood a bit longer. I guess that's just conjecture."

Your recollection is correct. And the possibiility that the structures would hold up if asbestos had been used throughout is far more than speculation---structural steel WITH asbestos fireproofing has a long engineering history--something the replacements did not have.

[HamiltonJay]

Guys, you are forgetting the main reason at least 1 of the towers fell, and it had nothing to do with retardant. The trusses failed, when that happened the floors failed, when that happened the rigidity of the entire tower failed! No retardant, not absbestos based, or otherwise could have saved those trusses! The sheer impact alone removed most of teh retardant from the structures. Asbestos would not have made a damns worth of difference!

The buildings were subjected to forces and incident to which they had NEVER been designed... in the end they failed because of it! Its amazing they remained standing as long as they did, but trying to try to argue abspestos would have save the towers is lunacy!

The towers were doomed the minute the planes hit, there was no other outcome that could have happened. Changing the fire retardant would not have changed anything. Those buildings fell and those people died because 19 sons of satan from the world religion of the devil decided to engage in a act of total barbarism! Period.

[FirstFlaBn]

Thanks. I have a background touching on structural systems and, as usual with anyone who has even a basic knowledge of any technical subject, the media is revealed as an ignorant pawn in the hands of the sensationalists - attorneys, politicians, and emotional participants.

No structural system on God's Green Earth has ever been tested to simulate what happened to the WTC towers.

Questions about fireproofing are incomplete without factoring in the structural damage. I have in my lap a design manual for steel joists. With no fire protection they are rated at 1 hour. Since both buildings lasted that long, then the system did pretty well considering the structural damage; and that's assuming the joists were the cause of failure (which I'm not convinced of yet).

As I recall, the WTC system relied not only on spray-on FP, but calculated in the fire resistant qualities of the ceiling tiles. If that scares you I'd advise you to never find yourself in a modern movie theater - they count the effect of the ceiling tiles. I bet malls do as well. Tell me how many tiles were in place after a plane going several hundred MPH passed nearby, not to mention the point you made about how much FP was scraped off. The jet fuel statement in the article is similarly ridiculous. Jet fuel doesn't burn that hot. The legitimate question would address the total fire load - a technical issue concerning how many BTUs of stuff that can burn. Jet fuel in this situation contributed way more to the fire load than the normal stuff an office building contains. If every building had to be designed to resist teror attacks with airplanes, only government could afford new buildings.

That leads us to the real (but unadressed) question: should government, with its sovereign immunity, be allowed to own buildings beyond what is essential for government services? Should the public and employees be warned that government building need not meet codes?

[HamiltonJay]

The failure of the trusses is all but given as the final straw for one of the towers. The other appears to have perhaps been a core columnn integrity breach.

The entire building got its rigidity from its internal floors supporting the external walls, when the floors began to fail (trusses supporting them gave way) there was nothing left for the outer walls to do on those areas except to buckle.

This would have been the same outcome for the other building as well, had not its interior columns weakened before the trusses/floors failed enmasse. That tower took a more direct impact, and likely had its interior columns openly exposed to the fire because any retardant they had would have been compromised simly by the sheer impact and schrapnel from it. This would have happened no matter what the material was.

The temperatures and forces that were exerted on those buildings was more than ANY design they were built for. The temperatures of the fires alone were we all above what even "abspestos" would have protected, not only in their intensity of heat, but their duration, and that doesn't even take into account the structural effects of just the phsycial impacts.

Granted no one knew on 9/11 that those blows were unavoidably lethal... Lord knows all wish they were not, but the reality is, they were. They were doomed from the moment they were hit, there was no other outcome. Personally I find it miraculous they survived as long as they did. Had those towers fallen say in 10 minutes of impact instead of over an hour after impact, the death toll from that day would have measured in the tens of thousands!

Sick saddistic bastards caused 9/11 not failed engineers or abspestor regulations! Anyone arguing that is an afront to decency and desecrates those who died that day.

[Psycho_Bunny]

Sauron's gonna be pissed.

[RJCogburn]

IIRC, shortly after 9/11 there was a story that a fellow whose company used asbestos to protect the structure said that after 1/3 or 1/2 way up, the rules on asbestos changed and they could no longer use it...thus the spray on material.

He said something to the effect, before 9/11, again IIRC, that a big fire would cause failure of the structure above the level at which the asbestos was used. It was discussed here at that time and I suppose could be found in the archives if somebody wanted to look.

should government, with its sovereign immunity, be allowed to own buildings beyond what is essential for government services?

No.

[Consort]

It looks like the towers were designed poorly and constructed poorly. I think that the Chrysler Bldg and the Empire State Bldg would have stood.

[coloradan]

... and the buildings that they do own should be compliant with all the laws they force on us, especially if any civilians work in them.

[Wonder Warthog]

One of the engineers who DESIGNED the twin towers was the one who pointed to the (lack) of asbestos above (I believe) the eightieth floor as the probable cause of the rapid collapse. It was his opinion that if all the structural steel had been so treated, that the towers would have held up sufficiently long to be completely evacuated. I suspect he knows/knew a hell of a lot more about the situation than either of you.

[HamiltonJay]

Warthog, you know how many people got out of the buildings above the impact zones? Do you????? 2, that's right exactly 2 people! Whether abspestos would have granted 15 more minutes of time before truss failures (which is nonsense anyway since it had been blown off during the impact and was being subjected to higher heats for longer durations than even "abspestos" would have tolerated). Would not have saved 1 more persons life!!

Trying to spin this horrific event into some pro abspestos argument is incredulous! Ignorance, abspestos is not a miracle! No design spec in the world could have saved those towers... no fire retardant in the world can prevent a steel truss from collapsing when dealing with a fire fueled by kerosene coating everything under it! The temperatures were far hotter than anything expected, and even your golden calf abspestos would not have prevented the failing of the towers. To make an argument it would have is absolute DRIVEL!

You know how many engineers worked on DESIGNING the twin towers? I bet it was a hell of a lot more than 1!... that's like saying 1 engineer who worked on the shuttle program decided the challenger exploded because an astronaught lost his gum... Those towers went down because of the actions of 19 saddistic sociopaths, and nothing more. Abspestos would not have save the towers.

I challenge you, go look at ANY and I do mean ANY steel building, HOME DEPOTS are a great one, because you can see the trusses.... go by fires from buildings of that design that HAD abspestos fire retardant, I've seen them, they fail, they collaps and they warp, bend and yeild! And they do it at far lower temps than what the WTC was under after having a kerosene fireball destroy 3 floors or more after having fire proofing ripped off by the explosions as well... this is absolute nonsense.

[Wonder Warthog]

"Warthog, you know how many people got out of the buildings above the impact zones? Do you????? 2, that's right exactly 2 people! Whether abspestos would have granted 15 more minutes of time before truss failures (which is nonsense anyway since it had been blown off during the impact and was being subjected to higher heats for longer durations than even "abspestos" would have tolerated). Would not have saved 1 more persons life!!"

Sorry, but you are WRONG. If the truss had been blown off during the impact, the building would have collapsed immediately. It did not. The cause of failure was heat-induced failure of the struss. The engineer I quoted is an expert in the specific area of heat protection of steel in high-rise buildings In the article, he gave examples of several buildings which would NOT have collapsed and quoted data to support his position. The article is here on FR somewhere.

The reason more people didn't get out is because they didn't have TIME. Maybe the folks above the impact zones were un-saveable, but those BELOW the impact zones certainly were not in that fix, and given more time, they COULD have gotten out. A world-class expert in insulating steel says that asbestos insulation would have given them that time.

I tend to believe him a lot more than I do you.

Plus you need to learn how to spell asbestos.