WTC7 - The fires failed Girder 44-79

[Miragememories]

"MM,

If a steel tower can partially collapse from fire, what is stopping one from totally collapsing?"

The OP and this thread's topic refer to WTC7, a 47-story steel-framed office tower covering an area roughly the size of a football field.

If you wish to start a new thread about fire and heat damage to electrical towers, railway tracks, etc., go for it.

MM

 

[Gamolon]

The OP and this thread's topic refer to WTC7, a 47-story steel-framed office tower covering an area roughly the size of a football field.

If you wish to start a new thread about fire and heat damage to electrical towers, railway tracks, etc., go for it.

MM

Not that you're splitting hairs or anything, but maybe I should have put the words "-framed office" between my two words of "steel tower", but I thought you'd be bright enough to figure that out.

So anyways, if a STEEL_FRAMED OFFICE TOWER can partially collapse, what would stop one from totally collapsing? What is the thought process? Is it your "universal/standard/widely used/ engineering science" that's practiced in all engineering firms?

You STILL have avoided this question.

 

[Miragememories]

"Maybe if I substitute common, standard, or familiar, it might assist you in grasping my meaning?

In the long engineering history of steel-structured office towers, there has never been any fire event that threatened or achieved a total structural collapse.

There is nothing supporting an exception to this well established history.

The NIST steel-expansion hypothesis is poorly argued and is based on a 'new' look at a scientific phenomenon that is very familiar to steel construction engineers. They are well aware that heated steel expands and weakens, and that cooling steel contracts and strengthens.

The NIST hypothesis is dependent on "old news" and with supporting legs so weak, that the hypothesis totally collapses when examined."

"I'll ask again since you seem to be avoiding these questions.

What is this "common", "standard", "familiar", or "universal" engineering science you are referring to? Are you suggesting that there is a design code for or common practice followed by structural engineers to prevent a global collapse due to ANY fire scenario?

Is this "design code" the reason that historically, no steel framed tower had ever suffered a total collapse due to fire?

Is this what you are claiming?"

"Are you ever going to answer this MM? Or are you stymied and don't want to give your answer because you know where it will lead?"

Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower.

Why?

Because from all their experience, education, and acquired knowledge about steel-structured highrise buildings, structural engineers found it inconceivable that any credible fire scenario could accomplish such an historical first.

That is until the NIST created a computer simulation that allowed natural fires to do what they had never done before..sort of. The graphic display of the computer modeled collapse does not accurately resemble what was observed in reality but it does have WTC7 collapsing.

Surprisingly, even though the engineering community's long understanding that steel office towers were invincible to total collapse from natural fires, the NIST's sensational hypothesis was absorbed with hardly a whimper.

But, in the 'drums of war' dark period that followed 9/11, it is hard to imagine that many structural engineers had a willingness to investigate and comment on the NIST's declaration that its WTC7 collapse hypothesis was proven.

MM

 

[NoahFence]

just stop it, TRUTHERS. You folks have no idea what you're talking about!!

 

[JayUtah]

That is until the NIST created a computer simulation...

How many terascale computer simulations have you personally created?

Surprisingly, even though the engineering community's long understanding...

Where and when did you get your engineering degree? Are you presently licensed to practice?

 

[Redwood]

Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower.

Humbug. The dangers of fire to steel have been known for ages. That's why fire-resistant measures, such as coatings and masonry have been applied to steel from the beginning.

The mighty Crystal Palace, one of the glories of Victorian architecture, stood for more than 80 years before it was destroyed by fire. If ever an unprotected steel (or cast iron) structure were to survive a massive fire, that would be it, as it was essentially a giant atrium, with minimal live load.
The Crystal Palace, before and after the fire:

Maybe they should have checked for thermite afterwards.

 

[Redwood]

Originally Posted by Miragememories
That is until the NIST created a computer simulation...

How many terascale computer simulations have you personally created?

I'm no computer expert, but shouldn't the whizzes at AE911 be able to run one themselves? If they don't have access to a large mainframe computer, couldn't they use a "Beowulf" array of smaller ones? They've had many years to do something like this.

 

[Justin39640]

I'm no computer expert, but shouldn't the whizzes at AE911 be able to run one themselves? If they don't have access to a large mainframe computer, couldn't they use a "Beowulf" array of smaller ones? They've had many years to do something like this.

They would... but that would take money away from spreading the truth in politically important places such as New Zealand, Hawaii, and Jamaica.

Any truther who paid into that scam is a sucker.

 

[JayUtah]

I'm no computer expert...

Good thing I am, then.

...but shouldn't the whizzes at AE911 be able to run one themselves?

Possibly. I don't know what resources they have.

If they don't have access to a large mainframe computer, couldn't they use a "Beowulf" array of smaller ones?

No one does this type of analysis on monolithic mainframes anymore. Massively parallel clusters, a la Beowulf, are the status quo. A 64-node cluster will run you about $250,000 from a rack-type vendor. However a terascale computer such as are used in the forefront of industry and science will run you about $1 million per teraflop. While they probably cannot afford this, they would possibly be able to afford renting time on one.

They've had many years to do something like this.

Indeed they have. For all the Truthers' whining about how the various investigative agencies got this model or that model wrong, none of them seems to have ventured a better solution that proves their point. In the epitome of passive aggression, they seem to suggest it's others' responsibility to test their propositions and prove or disprove them.

While I'm skeptical that AE911T has the physical resources to test their claims, I'm absolutely sure none of them has the know-how to set up the necessary models and simulations. It's a very demanding, very rare skill, even though standardized software tools are used in the execution of the simulation. Hence I'm inclined to relegate Truther criticism to wishful nipping at heels. Let them prove their metal by actually undertaking a proof of their claims in the highly rigorous field of computational mechanics.

 

[Animal]

Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower.

Why?

Because from all their experience, education, and acquired knowledge about steel-structured highrise buildings, structural engineers found it inconceivable that any credible fire scenario could accomplish such an historical first.

That is until the NIST created a computer simulation that allowed natural fires to do what they had never done before..sort of. The graphic display of the computer modeled collapse does not accurately resemble what was observed in reality but it does have WTC7 collapsing.

Surprisingly, even though the engineering community's long understanding that steel office towers were invincible to total collapse from natural fires, the NIST's sensational hypothesis was absorbed with hardly a whimper.

But, in the 'drums of war' dark period that followed 9/11, it is hard to imagine that many structural engineers had a willingness to investigate and comment on the NIST's declaration that its WTC7 collapse hypothesis was proven.

MM

How about not knowing the difference between an open web joist and a rolled steel section?

Oops....sorry......that is in the troofer realm.

 

[000063]

Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower.

Why?

Because from all their experience, education, and acquired knowledge about steel-structured highrise buildings, structural engineers found it inconceivable that any credible fire scenario could accomplish such an historical first.

That is until the NIST created a computer simulation that allowed natural fires to do what they had never done before..sort of. The graphic display of the computer modeled collapse does not accurately resemble what was observed in reality but it does have WTC7 collapsing.

Surprisingly, even though the engineering community's long understanding that steel office towers were invincible to total collapse from natural fires, the NIST's sensational hypothesis was absorbed with hardly a whimper.

But, in the 'drums of war' dark period that followed 9/11, it is hard to imagine that many structural engineers had a willingness to investigate and comment on the NIST's declaration that its WTC7 collapse hypothesis was proven.

MM

That entire post is just incredulity and evasion.

Everyone with any sense knows that unprecedented or unanticipated does not mean impossible. And as you know, no building over 30 stories was ever felled by controlled demolition, before or since 9/11.

And still nothing about the "engineering science" that would allow them to effectively design the building against an event that you just claimed was inconceivable. And if it was inconceivable, why was the steel fireproofed? Why is steel fireproofed in any steel building, including office towers, if engineers think collapses are impossible? Who are these engineers - not NIST or Truther - who said it was impossible? Not imaginary statements by imaginary engineers; what actual people said it couldn't happen?

 

[MarkLindeman]

Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower....

That is until the NIST created a computer simulation that allowed natural fires to do what they had never done before..sort of.

Can you document either part of this alleged shift in the opinions of practicing structural engineers: before and after "the NIST created a computer simulation"?

 

[Gamolon]

Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower.

Why?

If you asked a structural engineer, prior to NISTs findings, if he/she would 100% guarantee that any structural steel framed office building that they designed to NEVER, EVER totally/globally collapse due to unfought fires, do you think they would give you that guarantee?

Because from all their experience, education, and acquired knowledge about steel-structured highrise buildings, structural engineers found it inconceivable that any credible fire scenario could accomplish such an historical first.

So you've answered my question above correct? You think that every single structural engineer would make that guarantee above without hesitation?

That is until the NIST created a computer simulation that allowed natural fires to do what they had never done before..sort of. The graphic display of the computer modeled collapse does not accurately resemble what was observed in reality but it does have WTC7 collapsing.

What is the definition of a "natural fire"?

Surprisingly, even though the engineering community's long understanding that steel office towers were invincible to total collapse from natural fires, the NIST's sensational hypothesis was absorbed with hardly a whimper.

So the "standard/universal engineering science" that you think structural engineers use to design structural steel framed office towers is strictly the knowledge that no building ever totally/globally collapsed from fire previously, so they just go with what they had been doing???

Do you think structural engineers can design any steel framed office tower to be 100% impervious to total/global collapse due to unfought office fires? Yes or no?

 

[Miragememories]

"Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower."

"Humbug. The dangers of fire to steel have been known for ages. That's why fire-resistant measures, such as coatings and masonry have been applied to steel from the beginning.

The mighty Crystal Palace, one of the glories of Victorian architecture, stood for more than 80 years before it was destroyed by fire. If ever an unprotected steel (or cast iron) structure were to survive a massive fire, that would be it, as it was essentially a giant atrium, with minimal live load.
The Crystal Palace, before and after the fire:

Maybe they should have checked for thermite afterwards."

The glass, iron and wood Crystal Palace was not a steel framed office tower.

It did not suffer a total high speed collapse and its two towers remained standing until they were later demolished.

"The fire burned most of the night, melting the glass panels and softening the steel superstructure such that, one by one, the great supporting arches twisted and fell. By morning, nothing was left but a tangled ruin."
http://en.citizendium.org/wiki/Crystal_Palace

MM

 

[Spanx]

The glass, iron and wood Crystal Palace was not a steel framed office tower.

It did not suffer a total high speed collapse and its two towers remained standing until they were later demolished.

"The fire burned most of the night, melting the glass panels and softening the steel superstructure such that, one by one, the great supporting arches twisted and fell. By morning, nothing was left but a tangled ruin."
http://en.citizendium.org/wiki/Crystal_Palace

MM

Are you debunking yourself

 

[twinstead]

The glass, iron and wood Crystal Palace was not a steel framed office tower.

It did not suffer a total high speed collapse and its two towers remained standing until they were later demolished.

"The fire burned most of the night, melting the glass panels and softening the steel superstructure such that, one by one, the great supporting arches twisted and fell. By morning, nothing was left but a tangled ruin."
http://en.citizendium.org/wiki/Crystal_Palace

Supporting steel structures can and do soften and collapse in an extended fire. Your link supports that.

 

[JayUtah]

The glass, iron and wood Crystal Palace was not a steel framed office tower.

In what ways was it like a steel-framed office tower? In what ways was it not like a steel-framed office tower?

Be specific, and refer to determinate or indeterminate statics in your answer, as appropriate. You have insinuated to have knowledge of engineering that is material to your claims. I propose to test that knowledge. Will you comply?

Also, I previously asked you two simple questions you can answer without any research or undue effort: (1) do you have any firsthand experience with terascale computer simulations? (2) when and where did you obtain your engineering degree, and are you currently licensed to practice? Please answer those questions at your earliest convenience.

"...softening the steel superstructure..."

Elaborate on this portion of your quoted authority, using your own expertise, and tell us how it applies or does not apply to structural steel in the WTC office buildings. You are telling us that the Crystal Palace is not a suitable analogue to the structures you are interested in, yet your own authority describes effects in the Crystal Palace fire that parallel what your critics endeavor to make you understand about the WTC structures.

Please carefully distinguish the thermal effects on the Crystal Palace from the thermal effects on WTC in your structural analysis.

 

[Miragememories]

"Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower."

Why?"

"If you asked a structural engineer, prior to NISTs findings, if he/she would 100% guarantee that any structural steel framed office building that they designed to NEVER, EVER totally/globally collapse due to unfought fires, do you think they would give you that guarantee?"

I believe that I have given an adequate response to that question. Repeatedly re-phrasings serve no useful benefit to this 'discussion'.

"Because from all their experience, education, and acquired knowledge about steel-structured highrise buildings, structural engineers found it inconceivable that any credible fire scenario could accomplish such an historical first."

"So you've answered my question above correct? You think that every single structural engineer would make that guarantee above without hesitation?"

I said; "Before the NIST stated their findings, you would have been hard pressed to find a single practicing structural engineer who would believe it possible for natural fires to bring about the total high speed collapse of a steel office tower." I did not say that "every single structural engineer would make that guarantee"

"That is until the NIST created a computer simulation that allowed natural fires to do what they had never done before..sort of. The graphic display of the computer modeled collapse does not accurately resemble what was observed in reality but it does have WTC7 collapsing.

"What is the definition of a "natural fire"?"

You might want to ask a NIST supporter like Chris Mohr, sinceI believe he also uses the term in his writings.

Or you might like to look here;
http://www.aisc.org/WorkArea/showcontent.aspx?id=7046

"A natural fire, when uncontrolled, has distinct stages of growth, burning, and most notably, decay..."

"Surprisingly, even though the engineering community's long understanding that steel office towers were invincible to total collapse from natural fires, the NIST's sensational hypothesis was absorbed with hardly a whimper.

But, in the 'drums of war' dark period that followed 9/11, it is hard to imagine that many structural engineers had a willingness to investigate and comment on the NIST's declaration that its WTC7 collapse hypothesis was proven."

"So the "standard/universal engineering science" that you think structural engineers use to design structural steel framed office towers is strictly the knowledge that no building ever totally/globally collapsed from fire previously, so they just go with what they had been doing???

Do you think structural engineers can design any steel framed office tower to be 100% impervious to total/global collapse due to unfought office fires? Yes or no?"

bolding is mine

No building?

Again, I believe this question has been appropriately answered.

MM

 

[JayUtah]

bolding is mine... [re: natural fires]

You have simply listed one rather nebulously worded property of "natural fire." You are being asked to more precisely define what a "natural fire" is, and ultimately supply evidence that the fires in question fit that definition in enough particulars to make those properties pertinent.

Again, I believe this question has been appropriately answered.

No, you have merely repeated the same assertion every time it is questioned. You are being asked for evidence that the assertion is true. Please provide evidence that the assertion is true, or withdraw it.

 

[Spanx]

MM has a point. Steel frame buildings only collapse from the top down.

The following clip has no fire, just smoke being pulled from something I can't see

http://www.youtube.com/watch?v=8XMTALBYRNA&feature=youtube

Skip to 0.42 if you don't want to see the fire that's not really there.