What exactly does NIST say about collpase times

[Hornit]

I know some of you fine folks probably have gone over this more than me. I am NOT a truther. I am DEBUNKING many of them however. Im interested in what NIST said about collpase times. Specifically Im trying desperately to point out the giant fail in truthers claims that the towers (WTC's) fell at "free fall" speeds. Its obvious to me, but I want to know what NIST says since they keep pinging about NIST saying that they did.

I did read a LOT of the final reports years ago but Im sure I am not as well versed as some of you all are, so any help pointing me in the right direction is greatly appreciated. Thanks!

 

[ozeco41]

I don't know the answer off hand - many will and I'm sure you'll get the answer.

However the whole issue is a truther evasion tactic. Two main ones actually.

The underlying truther claim is that there was CD or OMHI (Other Malicious Human Intervention.) There wasn't and it is claimant's burden of proof to "prove" that there was. Not ours or yours to prove it wasn't. Given that what NIST said is actually irrelevant. And a second truther derail. The events happened on 9/11 and what NIST wrote years later cannot change historic fact. So if NIST wrote that WTC Towers fell after being hit by Santa's custard (Rudolph stumbled during a pre-xmas trial run over NY - and Santa's Xmas pudding dropped custard over WTC) That explanation would IMNSHO be false.

Reverse the direction - if what NIST said could change history all we need is a NIST report saying "No planes hit the Towers and they didn't fall" and "Hey Presto" all is restored. Despite the facetious style/example that logic is valid but a couple of levels beyond most including no doubt your truther opponents.

Bottom line is you will need to be very clear as to whether the argument is "Prove NIST Wrong" OR "Explain Collapses of WTC" but never the twain shall meet. NIST reporting is irrelevant to explaining what actually happened. They got some bits right and some bits wrong. To explain the collapses and accommodate NIST you need to decide which bits are right and which are wrong. Too confusing, too complicated. Easier to ignore NIST. Use their data but not their reasoning.

The second issue is the truther created meme that "free fall" is significant. It isn't. More specifically truthers imply that 'Free Fall' means CD and free fall only occurs with CD. Wrong on both counts. It doesn't so all arguments relying on it are falsified. Again you will not get truthers to face that reality either.

Bottom line for that one is that free fall is useless in distinguishing so called natural collapse from "CD".

Collapse occurs because of a collapse mechanism. There is no fundamental difference between CD initiated collapse mechanisms and those resulting from other causes including accidents.

There has been a lot of discussion of those key issues but it is scattered across the forum. Ask some focussed questions and I or many others will be able to point you to the material or summarise it - tailor it to your specific need.

 

[Robrob]

The second issue is the truther created meme that "free fall" is significant. It isn't. More specifically truthers imply that 'Free Fall' means CD and free fall only occurs with CD. Wrong on both counts. It doesn't so all arguments relying on it are falsified. Again you will not get truthers to face that reality either.

Bottom line for that one is that free fall is useless in distinguishing so called natural collapse from "CD".

Collapse occurs because of a collapse mechanism. There is no fundamental difference between CD initiated collapse mechanisms and those resulting from other causes including accidents.

^ This.

CT use "free fall" as a meaningless placeholder buzz word. You will never get one to explain to you what they mean by free fall, what it indicates or how it differs from any other fall mechanism.

Substitute it with "reverse the polarity of the warp core" and it makes as much sense.

 

[DGM]

I know some of you fine folks probably have gone over this more than me. I am NOT a truther. I am DEBUNKING many of them however. Im interested in what NIST said about collpase times. Specifically Im trying desperately to point out the giant fail in truthers claims that the towers (WTC's) fell at "free fall" speeds. Its obvious to me, but I want to know what NIST says since they keep pinging about NIST saying that they did.

I did read a LOT of the final reports years ago but Im sure I am not as well versed as some of you all are, so any help pointing me in the right direction is greatly appreciated. Thanks!

NIST did not go into great detail about the "speed of collapse" for the towers.

As ozeco41 pointed out this is a red herring and NIST did not bite on the towers. It was sad they did play into that bait on building 7.

 

[Architect]

Correct. They only went as far as initiation IIRC.

 

[JSanderO]

Not to mention that to precisely determine the end of the collapse was pretty difficult to say the least. Lots of dust so visual determination of the end was well nigh impossible except the for drop of the last core columns on the twin towers... which has nothing to do with the speed of descent of the destruction down from the plane strike zones.

The use of FF by truthers is a sort of twisted (il)logic. Where they assert FF and assume that it can only occur of the columns in the FF distance of the collapse were not there. And that can only happen with exploding them out of the way. But this is a very cartoon like thinking because once columns are mis aligned it's as if the lower one are structurally not there even if they are actually present such as the core columns of the twin towers. And what DID collapse in 10-14 seconds was the FLOORS and the facade did NOT collapse but fell away. No descent of the facade.

This represents a stunning failure to observe and to understand the movement... not to mention dismissing the nature of structure collapse of multi story structures.

 

[cjnewson88]

Wow, I wrote a pretty decent reply to this but it bugged out and didn't post. So i'll just rewrite the short version.

- NIST didn't go into collapse time.
- 9/11 Report said 10 seconds but that is not an engineering report.
- Free fall does not = controlled demolition anyway
- The towers fell at 18 seconds : 50% free fall
- If I earned $50,000 a year, but said I earned "near" $100,000, you would say I was exaggerating, or even a liar. When truthers say the buildings fell at free fall, or "near" free fall, they are exaggerating, or lying. But hey, since when have truthers cared about facts?

 

[ozeco41]

Correct. They only went as far as initiation IIRC.

Oooops....

Missed that one.. Must be age or boredom with 9/11.

 

[ozeco41]

Wow, I wrote a pretty decent reply to this but it bugged out and didn't post. So i'll just rewrite the short version.

If you are using Firefox there is an add-on - appropriately named "Lazarus" - it can "bring back the dead". It keeps a cache of your posting efforts at almost every change through the drafting/editing and posting stages.

So if you, your browser or a hardware/power glitch destroy your Award Winning Prize Document -- you can recover it easily.

BTW have you noticed the Murphy's Law corollary. The only time I lose posts is when they are peak examples of my brilliance?

 

[ozeco41]

... And what DID collapse in 10-14 seconds was the FLOORS and the facade did NOT collapse but fell away. No descent of the facade.

Good point Sander.

 

[000063]

Correct. They only went as far as initiation IIRC.

Which was itself called a dodge by many truthers.

 

[ozeco41]

Which was itself called a dodge by many truthers.

Which raises some interesting points as we see the sun setting slowly in the West on 9/11 discussions.

Back "in the day" truthers used to make a lot of fuss about "squibs" and the presumed use of explosive cutting in the "progression" stage of Global collapse. I don't recall that being raised as an issue for some time.

And it was probably the closest the truthers ever got to trying to show how explosives were allegedly used. All the other claims being quite general.

Then the two big ground shifts may have swallowed up those details. I mean the shift of focus to WTC7 and the S Jones marketing ploys about thermXte.

We saw the emphasis swing to WTC7 as the delaying tactics of defeat during a "withdrawal" stage. (Military talk for "retreat" - the military don't use the word "retreat" The truthers were very much in retreat.)

The truthers had essentially lost any real battle over CD at the Twins - mainly because sufficient evidence against CD was available and visible. That despite the almost universal acceptance by debunkers of "reversed burden of proof" - "we" were willing to prove them wrong and most of us still are. Even though it is their burden to prove they are right. Which they totally fail to do.

With WTC7 the evidence was mostly hidden and "we" had a much harder job proving them wrong so WTC7 was a bonus for truthers in allowing them to prolong the discussion after they really had lost it.

And no need to continue this rant into "thermXte" which was nothing more that a marketing ploy by Jones who was losing "brand recognition" to Gage. He played it twice but still lost out. Interesting that "thermXte" still gets attention BUT everyone seems to have forgotten Jones.

 

[Brainster]

Not sure if it was NIST or the 9-11 Commission, but they made a simple mistake; they looked at the earthquake data and assumed that gave them the collapse times. In fact, what that gave them was the period of time in which substantial amounts of the buildings were colliding with the ground, not the collapse times.

 

[Mark F]

One important thing to remember:

The speed at which something falls tells you nothing about WHY it fell.

 

[jaydeehess]

Wow, I wrote a pretty decent reply to this but it bugged out and didn't post. So i'll just rewrite the short version.

- NIST didn't go into collapse time.
- 9/11 Report said 10 seconds but that is not an engineering report.- Free fall does not = controlled demolition anyway
- The towers fell at 18 seconds : 50% free fall
- If I earned $50,000 a year, but said I earned "near" $100,000, you would say I was exaggerating, or even a liar. When truthers say the buildings fell at free fall, or "near" free fall, they are exaggerating, or lying. But hey, since when have truthers cared about facts?

The first clue in the hilted is that they reported it fell in "ten seconds" , spelling out the word 'ten' rather than use a more technical form such as '10.0 second'.

Second, NIST refers to the impact of the first large pieces of debris from the towers as hitting in a certain amount of time, iirc 12 seconds. That of course cannot be a measure of collapse zone reaching the ground floor.

 

[pgimeno]

I know some of you fine folks probably have gone over this more than me. I am NOT a truther. I am DEBUNKING many of them however. Im interested in what NIST said about collpase times. Specifically Im trying desperately to point out the giant fail in truthers claims that the towers (WTC's) fell at "free fall" speeds. Its obvious to me, but I want to know what NIST says since they keep pinging about NIST saying that they did.

I did read a LOT of the final reports years ago but Im sure I am not as well versed as some of you all are, so any help pointing me in the right direction is greatly appreciated. Thanks!

I'll address your exact question, but it's a bit messy.

NIST mostly don't address the speed of fall for the towers in their reports; they address it in a separate FAQ:

6. How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2)—speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)?

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2. These elapsed times were based on: (1) precise timing of the initiation of collapse from video evidence, and (2) ground motion (seismic) signals recorded at Palisades, N.Y., that also were precisely time-calibrated for wave transmission times from lower Manhattan (see NCSTAR 1-5A).
​

Note they talk about the first exterior panels that fell. They were detached thus fell in free fall. See for example this pic that shows these panels quite low in comparison with the collapse of the rest of the tower:

http://thriceholy.net/JPGs/collapse.jpg

which is an excellent argument that debunks any free fall claims in a whim: if these fragments fell at free fall, starting to fall at the same time the collapse initiated, and the collapse of the rest of the building was slower than them, the rest of the building could NEVER be collapsing at free fall speed. Plain and simple.

But back to what NIST say, at the end of that point they conclude:

Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.​

They point to NCSTAR 1, section 6.14.4 ("Events Following Collapse Initiation") which may be the only part of the reports that addresses the speed of fall of the towers.

Source: http://www.nist.gov/public_affairs/factsheet/wtc_faqs_082006.cfm

Then there's WTC7. They estimated a collapse speed in their preliminary report of 5.4 seconds for 18 stories, or 40% above freefall. In their final report, however, they made an estimation of the collapse speed over time, and concluded that the building came down at free fall during the second stage of the collapse, when the broken columns of the façade provided negligible support.

The truthers explain such a free fall by pointing out that falling in free fall requires all supports of the structure to be removed. However, there's a problem. Independent measurements based on video reveal that the speed of fall exceeded that of free fall by a non-negligible amount. And a simple removal of the supports does NOT explain that. We're back to looking for a physics explanation, and while it would have sounded too academic to say that for free fall to be produced, the downward force must equal the upward force plus mass times gravity, thing is that when free fall is exceeded, that consideration is no longer merely academic, and must be accounted for when looking for an explanation: for an acceleration greater than free fall to happen, the downward force must exceed the upward force plus mass times gravity. And that can't be explained by explosives or removal of supports.

There are other threads where this is addressed, feel free to take a look.

 

[CastorTroyy]

Good luck to you. I have spent some time debunking some truther acquaintances as well, and even venturing (dare I?) onto YouTube to respond to some of the comments - many of which display astronomical levels of ignorance (willful or otherwise) - that I just cannot ignore.

However with Youtube truthers, 99% of the time the result is the same - it turns into a game of whack-a-mole, where I continue to debunk claim after claim without the truthers refuting or analyzing my rebuttals. They glance over them as though the content doesn't undermine their entire premise, and just keep yammerin' on and on and on and....

 

[JSanderO]

I'll address your exact question, but it's a bit messy.
...

Then there's WTC7. They estimated a collapse speed in their preliminary report of 5.4 seconds for 18 stories, or 40% above freefall. In their final report, however, they made an estimation of the collapse speed over time, and concluded that the building came down at free fall during the second stage of the collapse, when the broken columns of the façade provided negligible support.

There were no columns in the facade of 7wtc. It had a curtain wall which was hung on angle clips from the spandrels.

Of the 58 columns just inside the perimeter to which the spandrel beams were connected only 26 of them actually coupled with bedrock The rest were supported on braced framed which stood 7 stories high on the east and west sides. Eight of the 57 were on the north side and on the end of the 8 MG27 cantilever girders. The columns 25 columns of the perimeter which did couple to bedrock were ALSO part of the braced frames.

What appears to be seen descending is the curtain wall still attached to the spandrels and the columns. There is evidence that the floor beams had broken free and the floors had collapsed with them into the core area by the time we see the curtain wall descend. That evidence is the fact that the entire north curtain wall bow inward like a fold with a vertical line opposite column 73 which was at the NE corner of the core and supported the west end of transfer truss 1. Curtain wall can't kink inward if there are floors behind them. Ergo no floors when we see the kink. Ergo what you see collapsing is not the building but the curtain wall w/ the 58 columns and spandrels attached. This had no resistance because when it was released the braced frames on the east and west perimeter had been pulled toward the core by the collapse of TT1, TT2 and TT3. Those braced frames stood about 105' tall or the alleged distance of free fall (more or less) descent.

The progression happened pretty quickly but the visual evidence of the insides coming apart is the east west swaying and then the drop of the two penthouses one after the other and finally the curtain wall descends in about 7 seconds.

 

[Gamolon]

There were no columns in the facade of 7wtc. It had a curtain wall which was hung on angle clips from the spandrels.

Of the 58 columns just inside the perimeter to which the spandrel beams were connected only 26 of them actually coupled with bedrock The rest were supported on braced framed which stood 7 stories high on the east and west sides. Eight of the 57 were on the north side and on the end of the 8 MG27 cantilever girders. The columns 25 columns of the perimeter which did couple to bedrock were ALSO part of the braced frames.

What appears to be seen descending is the curtain wall still attached to the spandrels and the columns. There is evidence that the floor beams had broken free and the floors had collapsed with them into the core area by the time we see the curtain wall descend. That evidence is the fact that the entire north curtain wall bow inward like a fold with a vertical line opposite column 73 which was at the NE corner of the core and supported the west end of transfer truss 1. Curtain wall can't kink inward if there are floors behind them. Ergo no floors when we see the kink. Ergo what you see collapsing is not the building but the curtain wall w/ the 58 columns and spandrels attached. This had no resistance because when it was released the braced frames on the east and west perimeter had been pulled toward the core by the collapse of TT1, TT2 and TT3. Those braced frames stood about 105' tall or the alleged distance of free fall (more or less) descent.

The progression happened pretty quickly but the visual evidence of the insides coming apart is the east west swaying and then the drop of the two penthouses one after the other and finally the curtain wall descends in about 7 seconds.

Question.

Looking at the PDF, particularly the enlarged "Transfer Truss #1" detail and the detail to the right of that, shouldn't E4 be labeled as "beyond" instead of E3?

Or am I not visualizing this correctly?

Thanks.

 

[Gamolon]

Question.

Looking at the PDF, particularly the enlarged "Transfer Truss #1" detail and the detail to the right of that, shouldn't E4 be labeled as "beyond" instead of E3?

Or am I not visualizing this correctly?

Thanks.

Looks like the "Load Transfer Frame" detail on the PDF has E3 and E4 labeled incorrectly according to drawing E6.