WTC7 - The fires failed Girder 44-79

[Gamolon]

But the NIST blamed WTC7's migrating office fires for causing a major core column failure that lead to the complete destruction of that 47 story steel office tower.

A lower floor, heavy steel, fire-protected, undamaged, column.

Just to show that your rendition of the NIST's explanation of how WTC7 collapsed, that being from fire causing column 79 to fail, is totally off base, here is what they say.

The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.
According to the report's probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.
Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.

The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, and 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.

So no, fire did not cause column 79 to fail as you incorrectly think.

 

[000063]

That does not show a steel office tower.

It shows a steel construction crane.

The steel tower supporting the crane did not collapse.

The failure was where the crane's arm connected to the top of the crane tower.

It is quite understandable the failure occurred at that connection since it would be under enormous torque. I believe in NYC recently, strong winds achieved a similar result.

Wrong, as Justin and Gamolon pointed out.

It has never been my argument that fire will not weaken steel.

That's not an admittance that it will, I note, nor admitting that it can collapse steel.

But the NIST blamed WTC7's migrating office fires for causing a major core column failure that lead to the complete destruction of that 47 story steel office tower.

Wrong, as Gamolon pointed out, despite your attempts to move the goalposts. You said they said the fire made the column collapse. Then the fire caused the heat that made the column collapse. What the report actually said was that the heat caused a series of events that led to the collapse. Neither heat, nor fire directly affected 79.

A lower floor, heavy steel, fire-protected, undamaged, column.

Good luck finding an example of any fire, fought or unfought, causing a failure in a steel office tower core column that gives support to the NIST hypothesis.

I provided a few other characteristics of WTC 7, and asked you to find any other steel tower that met all them and didn't collapse.

You ignored it.

Quit trying this "unprecedented, therefore impossible" nonsense.

Please show us the source of a 'dictum' that states; "one can expect steel office towers to totally collapse if they are subjected to unfought office cubicle fires"?

MM

 

[Gamolon]

Were those fires not the source of the heat on which the NIST based its WTC7 total collapse initiation hypothesis?

MM

Do you not understand that between the above quote from you and the next quote from you, that you have effectively "moved the goalposts"?

But the NIST blamed WTC7's migrating office fires for causing a major core column failure that lead to the complete destruction of that 47 story steel office tower.

A lower floor, heavy steel, fire-protected, undamaged, column.

Do you not see the difference in either quote?

In the first quote, you claim that the heat from the fires caused collapse initiation. That initiation was the thermal expansion of the floor beams, which pushed the girder at column 79 on floor 13 from it's seat, which caused the floor to collapse onto the floors below, which caused the successive collapse OF those floors below, which left column 79 unsupported for those floors. THEN column 79 buckled due to the load being to much for the NOW unsupported portion of column 79.

In the second quote, you claim that the heat from the fire caused column 79 ITSELF to fail alone. Your belief that the heat failed column 79 all by itself without the thermal expansion or floors failures is proven by your statement that of "A lower floor, heavy steel, fire-protected, undamaged, column."

So which scenario do you think the NIST explains to have happened?

1. Heat from the fires weakened column 79 caused it alone to fail an initiate the collapse

or

2. Heat from the fires caused thermal expansion of the floors beams to push the girder at column 79, floor 13 from it's seat, which caused the subsequent floors below to fail, which left column 79 unsupported by those floors, which caused the load to fail column 79 at that unsupported location

 

[Miragememories]

"...But the NIST blamed WTC7's migrating office fires for causing a major core column failure that lead to the complete destruction of that 47 story steel office tower.

A lower floor, heavy steel, fire-protected, undamaged, column.

Good luck finding an example of any fire, fought or unfought, causing a failure in a steel office tower core column that gives support to the NIST hypothesis.

Please show us the source of a 'dictum' that states; "one can expect steel office towers to totally collapse if they are subjected to unfought office cubicle fires"?"

"Is that what they say happened MM? The fires caused column 79 to weaken and then fail?

That's it?

If that's the case, you're lying then."

No.

The NIST is claiming that the sustained heat generated by the those moving cubicle fires on Floors 7-13, was held in place long enough to make steel do something every engineer, and most kids, studying structural steel are aware of, heat makes steel expand.

After many years following 9/11, struggling for a politically acceptable engineering finding, the NIST fell back on what worked with their WTC Twin Towers Collapse Final Report.

In a nutshell, the NIST claims that the total high speed collapse of the 47-story WTC7 was the unforeseen consequence of unfought fires causing so much steel expansion that it destabilized column 79 sufficiently to make it buckle.

Sure WTC7 was an unusual building. But the same universal engineering science of the time was applied to its design and construction.

Under-engineering the lower floors of WTC7 was last thing building engineers wanted to do.

Primarily because of the power sub station it was built over, but they also wanted the lower floors to be customizable for new clients..

Most surprisingly, given the sensational nature of the NIST steel-expansion claim, nothing to support their hypothesis appears to have been discovered in the investigations of all the impressive, largely unfought steel office tower fires that occurred before 2001.

Not a clue suggesting that the fire in WTC7 would be so special.

MM

 

[DGM]

So which scenario do you think the NIST explains to have happened?

You really don't understand how propaganda works.

 

[Gamolon]

But the same universal engineering science of the time was applied to its design and construction.

And here is the crux of your problem MM. What "universal engineering science" was applied to WTC7 that would have made it impervious to total collapse due to fire? Are you suggesting that the engineers looked at every single possible permutation of fires, weakened steel, failed connections, load transfers, etc. and came up with a design to stand up to every possible situation?

Under-engineering the lower floors of WTC7 was last thing building engineers wanted to do.

So you think that the engineers who designed those floors did studies regarding how those floor beams would react to varying degrees of fire? Let me ask you a question and see if you'll even give me an honest answer. Does a structural engineer analyse every possible fire scenario in order to 100% guarantee a building will not totally collapse if an unfought fire occurs?

Most surprisingly, given the sensational nature of the NIST steel-expansion claim, nothing to support their hypothesis appears to have been discovered in the investigations of all the impressive, largely unfought steel office tower fires that occurred before 2001.

Not a clue suggesting that the fire in WTC7 would be so special.

MM

So according to you, all steel framed towers will all react exactly the same when subjected to unfought fires based on history. Is that correct? If so, please explain why the Windsor tower partially collapsed and the Meridian tower didn't.

So, in closing, please list the reason why no steel framed tower should never totally collapse due to fire. Is it because of your historical proof that none ever did? Or is it the fact that you think structural engineers design steel towers to not globally collapse due to fire? Maybe both? Maybe something else?

 

[Gamolon]

No.

No?

Then why did you put emphasis on column 79 with qualifying words such as and "fire protected" in your explanation?

What does column 79 being "fire protected" have to do with the NIST's explanation of how column 79 buckled?

 

[Justin39640]

No?

Then why did you put emphasis on column 79 with qualifying words such as and "fire protected" in your explanation?

What does column 79 being "fire protected" have to do with the NIST's explanation of how column 79 buckled?

It's called being disgustingly dishonest. (IMHO)

 

[Animal]

It's called being disgustingly dishonest. (IMHO)

i.e being a troofer

 

[ozeco41]

It's partly our own problem because we chase trollery down into the details they choose and lose the context.

If we work down from the context here rather than fall for the truther/trolls preferred approach from the bottom up some key points are:

1) There was no CD;
2) The east penthouse fell early in the global collapse;
3) Col 79 was under that penthouse;
4) Therefore Col 79 failed as part of the collapse;
AND that last point is a subset of the overall context
AND all this recent debate is about a subset of that subset - the question of whether whether NIST got it right
AND much of this recent debate is about a subset of that subset of a subset - whether or not certain posters either misunderstand or are misrepresenting what NIST said.

none of which changes:
A) No CD;
B) East Penthouse fell; AND
C) Col 79 must have failed.

And, since those three are true, who cares whether the fires directly affected Col 79 OR affected Col 79 indirectly by acting on related components?

Or, from my perspective, whether NIST was right.

What happened on 9/11 happened on 9/11 and, even if NIST got a detail wrong in a report some years later, no report can change what happened years earlier....notwithstanding truther beliefs to the contrary.

 

[000063]

No.

The NIST is claiming that the sustained heat generated by the those moving cubicle fires on Floors 7-13, was held in place long enough to make steel do something every engineer, and most kids, studying structural steel are aware of, heat makes steel expand.

You moved the goalposts again.

After many years following 9/11, struggling for a politically acceptable engineering finding, the NIST fell back on what worked with their WTC Twin Towers Collapse Final Report.

In a nutshell, the NIST claims that the total high speed collapse of the 47-story WTC7 was the unforeseen consequence of unfought fires causing so much steel expansion that it destabilized column 79 sufficiently to make it buckle.

You made up the term "total high-speed collapse" and are trying to pass it off as something sciencey sounding. You are fooling literally no one.

NIST said the fires caused steel expansion and structural failures, which led to 79's collapse.

Sure WTC7 was an unusual building. But the same universal engineering science of the time was applied to its design and construction.

Under-engineering the lower floors of WTC7 was last thing building engineers wanted to do.

Primarily because of the power sub station it was built over, but they also wanted the lower floors to be customizable for new clients..

Most surprisingly, given the sensational nature of the NIST steel-expansion claim, nothing to support their hypothesis appears to have been discovered in the investigations of all the impressive, largely unfought steel office tower fires that occurred before 2001.

Not a clue suggesting that the fire in WTC7 would be so special.
MM

Um.

 

[Miragememories]

"But the NIST blamed WTC7's migrating office fires for causing a major core column failure that lead to the complete destruction of that 47 story steel office tower.

A lower floor, heavy steel, fire-protected, undamaged, column."

"Is that what they say happened MM? The fires caused column 79 to weaken and then fail?

That's it?

If that's the case, you're lying then."

"No.

The NIST is claiming that the sustained heat generated by the those moving cubicle fires on Floors 7-13, was held in place long enough to make steel do something every engineer, and most kids, studying structural steel are aware of, heat makes steel expand.

After many years following 9/11, struggling for a politically acceptable engineering finding, the NIST fell back on what worked with their WTC Twin Towers Collapse Final Report.

In a nutshell, the NIST claims that the total high speed collapse of the 47-story WTC7 was the unforeseen consequence of unfought fires causing so much steel expansion that it destabilized column 79 sufficiently to make it buckle."

"No?

Then why did you put emphasis on column 79 with qualifying words such as and "fire protected" in your explanation?

What does column 79 being "fire protected" have to do with the NIST's explanation of how column 79 buckled?"

Emphasis on 'fire protected'?

"A lower floor, heavy steel, fire-protected, undamaged, column."

After the collapse of WTC1, that 'was' the true condition of column 79.

I am well aware that the NIST hypothesis is based on the premise that heat-induced steel expansion lead to a sudden loss of lateral support for column 79 over 5 floors, causing it to buckle.

And I think it is important that it be noted that this critical column was fire-protected against ill effect from those passing office cubicle fires.

MM

 

[Gamolon]

Emphasis on 'fire protected'?

"A lower floor, heavy steel, fire-protected, undamaged, column."

After the collapse of WTC1, that 'was' the true condition of column 79.

I am well aware that the NIST hypothesis is based on the premise that heat-induced steel expansion lead to a sudden loss of lateral support for column 79 over 5 floors, causing it to buckle.

And I think it is important that it be noted that this critical column was fire-protected against ill effect from those passing office cubicle fires.

MM

So you're telling me that you think the engineers, during the design phase the steel framing for WTC7, analyzed/did calculations for a scenario in which floor 13 and those below failed due to thermal expansion, fell down through the interior leaving that portion of column 79 unsupported, and then using those calculations, designed column 79 to resist failure if that scenario ever occurred?

Based on your following quote, you do.

But the same universal engineering science of the time was applied to its design and construction.

So please. Explain to us all what "universal engineering science" was utilized to foresee and prevent that column failure.

Basically what you're claiming with your "no steel framed tower has ever collapsed before" and "same universal engineering science" garbage is that structural engineers have figured out how to make towers 100% impervious fires and can 100% guarantee that any building they design will NEVER, EVER suffer a global collapse.

Ask any structural engineer if they will guarantee this.

 

[DGM]

I am well aware that the NIST hypothesis is based on the premise that heat-induced steel expansion lead to a sudden loss of lateral support for column 79 over 5 floors, causing it to buckle.


MM

I hi-lighted the part that you still got wrong.

Why do you keep posting these things claiming you understand the NIST report when you clearly don't. Do you think we wont notice?

 

[Gamolon]

After the collapse of WTC1, that 'was' the true condition of column 79.

So what??

How does the fact that it was "fire protected" have any bearing on if it could support the load it had to take on AFTER the surrounding floors fell away from it?

Do you think those floors (13 and below) helped keep column 79 from buckling while supporting the load it did when they were connected to it?

 

[GlennB]

I am well aware that the NIST hypothesis is based on the premise that heat-induced steel expansion lead to a sudden loss of lateral support for column 79 over 5 floors, causing it to buckle.

And I think it is important that it be noted that this critical column was fire-protected against ill effect from those passing office cubicle fires.

"Fire-protected" is not an absolute. Steel members in such a building are fire rated, according to their ability to withstand the effects of fire.

But, as has been pointed out to you several times, col 79 didn't fail all by itself. It failed because lateral support - bit by bit - failed first. The beams and girders and connections were exposed to conditions that exceeded their fire rating.

You might want to look up "slenderness ratio" and buckling^WP in relation to such columns. It might be that col 79 would have failed even if its temperature had itself barely been raised by 1°C, simply because the failed girders made its now unsupported length too slender to support its load.

No shocks here ... move along.

 

[Animal]

"Fire-protected" is not an absolute. Steel members in such a building are fire rated, according to their ability to withstand the effects of fire.

But, as has been pointed out to you several times, col 79 didn't fail all by itself. It failed because lateral support - bit by bit - failed first. The beams and girders and connections were exposed to conditions that exceeded their fire rating.

You might want to look up "slenderness ratio" and buckling^WP in relation to such columns. It might be that col 79 would have failed even if its temperature had itself barely been raised by 1°C, simply because the failed girders made its now unsupported length too slender to support its load.

No shocks here ... move along.

Not to mention the whole "heat rising" thing......It would be quite expected for joists and girders at ceiling/deck height to be more affected by fire than the certical column.

And the real term is 'fire resistive' assembly. Nothing is "fire protected". The assembly is rated for its resistance to fire based on laboratory tests, often by UL and are designated by hour (or partial hour) resistance. However, that resistance rating is based on the asembly being built in the same manner it was tested, not damaged nor altered by subsequent contruction.

(Not directed at GlennB)

 

[Justin39640]

Emphasis on 'fire protected'?

"A lower floor, heavy steel, fire-protected, undamaged, column."

Yeah, why do you need to word it like that. No one is arguing that the fire weakened that column. The fire weakened its support and being unsupported, it failed (buckled). Length, not heat, killed column 79 and ultimately the building. Whether or not it was "fire protected" doesn't matter in the least and it seems dishonest to say it the way you did.

After the collapse of WTC1, that 'was' the true condition of column 79.

When after? 5 minutes or 5 hours? At some point it lost its support and buckled.

I am well aware that the NIST hypothesis is based on the premise that heat-induced steel expansion lead to a sudden loss of lateral support for column 79 over 5 floors, causing it to buckle.

Oh good... then I assume that's the end of the "column 79 was fire protected" bull ****.

And I think it is important that it be noted that this critical column was fire-protected against ill effect from those passing office cubicle fires.

MM

Ah, Christ on a pony! It's not important in the least! Fire didn't directly fail 79. Stop it already.

 

[triforcharity]

Emphasis on 'fire protected'?

"A lower floor, heavy steel, fire-protected, undamaged, column."

After the collapse of WTC1, that 'was' the true condition of column 79.

I am well aware that the NIST hypothesis is based on the premise that heat-induced steel expansion lead to a sudden loss of lateral support for column 79 over 5 floors, causing it to buckle.

And I think it is important that it be noted that this critical column was fire-protected against ill effect from those passing office cubicle fires.

MM

Yes, fire protected for up to TWO (2) hours. Not 5, not 7, TWO.

TWO hours. WITH proper adhesion. We know, from experience, that SFRM has one major weakness. Application must be done PERFECTLY.

I don't know the condition of the SFRM in 7WTC, but maybe someone else does. However, having dealt with the stuff time and time again, very few are done perfectly.

Still, even applied perfectly, it's still only rated for TWO hours. Not seven.
And why do you keep saying "passing" fires? Does heat not radiate in your world?

 

[GlennB]

And why do you keep saying "passing" fires? Does heat not radiate in your world?

Indeed. And the residual heat can be pretty intense. Fire crews can spend many hours - days even - damping down the remains of major fires to prevent re-ignition.

On a much smaller scale I've had bonfires of tree prunings whose embers, when reloaded the next morning, were still hot enough to eventually ingite the new fuel.

Truther mentality is remarkably literal. "The fire had passed by col 79 at 3:30" (or whatever) apparently equates to "So we can assume that area was back to normal room temperature". Weird. I can only guess it involves a subconcious switching-off of all knowledge and personal experience in order to allow the delusion to survive, against whatever odds. I think R.Mackey wrote a big fat paper on the subject