Merged Core-led collapse and explosive demolition

[beachnut]

Hi guys, Im new here and although Ive read through as many of the pages for this thread as I can atm, I havent finished them all so I apologise if this has been covered.

Im genuinely curious about the speed at which all 3 building fell. (I know there was a little posted about WTC7). My knowledge of engineering or whatever topic it would be, is very limited so would somebody explain to me how a 92 story building can collapse at almost free fall speed?

The pancake theory the report is so fond of, would still mean it should have fallen at 92 seconds if 1floor = 1 second to collapse, or at best 46 secs if its 0.5 seconds per floor (if I've understood correctly).

How can 92 stories fall in under 10? I find it hard to believe that any collapse theory could explain a fall so quick.

Please dont jump down my throat like you have been with each other, I am neither conspiracist or debunker, i just dont know enough about things like this and I would like to find out.

Many thanks for any help you can give me
- Ash

... get a video and time the collapse. What time did you get?

What report is fond of the "pancake" theory?

 

[DGM]

Hi guys, Im new here and although Ive read through as many of the pages for this thread as I can atm, I havent finished them all so I apologise if this has been covered.

Im genuinely curious about the speed at which all 3 building fell. (I know there was a little posted about WTC7). My knowledge of engineering or whatever topic it would be, is very limited so would somebody explain to me how a 92 story building can collapse at almost free fall speed?

The pancake theory the report is so fond of, would still mean it should have fallen at 92 seconds if 1floor = 1 second to collapse, or at best 46 secs if its 0.5 seconds per floor (if I've understood correctly).

How can 92 stories fall in under 10? I find it hard to believe that any collapse theory could explain a fall so quick.

Please dont jump down my throat like you have been with each other, I am neither conspiracist or debunker, i just dont know enough about things like this and I would like to find out.

Many thanks for any help you can give me
- Ash

Welcome.
The answer is gravity and the fact the buildings were mostly air. Other than that you will need to understand much more technical issues.

Have you read (or understand) the NIST reports?

 

[aggle-rithm]

Hi guys, Im new here and although Ive read through as many of the pages for this thread as I can atm, I havent finished them all so I apologise if this has been covered.

Yes...in this thread and many others.

Im genuinely curious about the speed at which all 3 building fell. (I know there was a little posted about WTC7). My knowledge of engineering or whatever topic it would be, is very limited so would somebody explain to me how a 92 story building can collapse at almost free fall speed?

The only people who find this surprising are people who don't know that much about structural engineering and failure analysis. But that in itself isn't enough to dismiss the question.

The answer is this: When ordinary, everyday things are scaled up to massive sizes, like in the range of 1000 feet tall, they no longer behave the way we expect them to. When the WTC towers collapsed, millions of pounds of steel and concrete fell onto structures that were designed only to hold a static load. It seems counterintuitive that such a massive assembly of concrete and steel would offer very little resistance to the falling portion of the building, but it does. And engineers can show you the math that shows it is possible, if you're willing to learn.

 

[Ashurie]

Thanks for the reply guys I have read parts of NIST but ill be honest, a lot is beyond me at the moment. One day when i have enough time ill really go through everything and give myself the time to understand.

But thanks for helping me out at the moment. Im sure Ill need to bug you all for more things I dont understand

 

[Ashurie]

... get a video and time the collapse. What time did you get?

What report is fond of the "pancake" theory?

Sorry, didnt see your reply. When I first came across pancake theory, it was a while ago and ive only just got back to looking at stuff. Ill look back through it and let you know tomorrow the report Im on about (its the main one the gvt issued and i feel stupid for not remembering the name!)
Collapse wise, from what i remember, i counted around 7-8 seconds for collapse but Ive seen more accurate timings done that were about the same.

 

[Jackanory]

With north wall, west wall and south wall failing by having the upper wall fall out and over the lower wall,

and with minimal tilt of less than 1 degree over which all core and perimeter columns failed,

and with pull-in of the northwest corner from 9.5 seconds before collapse,

and with the antenna shifting eastward and downward from 9.5 seconds before collapse


Isn't it finally time to admit WTC1 collapsed through the core?


Considering that the NIST report didn't report any of these movements and got their own observations quite wrong, isn't it time to move your own personal understanding beyond recitations of the official report?

You have more than enough information to see evidence of failure through a central downward pull at minimal angle. Only some queer loyalty to the NIST stops you from seeing the obvious.

Yet you still can't quite get the Cable Dem, CD and explosives to fit your senario. NIST this and NIST that. Nit Picking at NIST? NIST failed miserably? NIST lied? All the arguements under the sun of how NIST got it so wrong or NIST failed to do a proper analysis or NIST didn't look at this in that way.........blah blah blah blah blah. All ya tech wizardry, yet you remain static and routed to a terrorist attack with 'no cables, CD or explosive used'. zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

 

[Animal]

Ah, I think I see your problem.

You don't understand a basic property of large buiildings like this...tilts will tend to self-correct as a building collapses. That is because the building is not designed to take huge lateral forces, and any tilt beyond a certain small degree will cause the tilting part of the structure to fail and fall straight down, obeying the laws of gravity.

So it's not just the crush-down, crush-up that causes the failure, it's the fact that gravity is acting on members that are tilted far beyond their design capacity.

Sure, the builders COULD have shored up the lateral supports in these buildings, so it would stay in one piece as it's tilted over to one side, but...what would be the point?

You don't have it quite right. Tall buildings are designed to resist very large lateral forces (the wind) The gravity loads are secondary and easier to resist. As a result a the building will fail from gravity long before it "topples"
The designers would have had to greatly increase the gravity carrying members, not the lateral ones .

 

[ozeco41]

Thanks for the reply guys I have read parts of NIST but ill be honest, a lot is beyond me at the moment. One day when i have enough time ill really go through everything and give myself the time to understand.

But thanks for helping me out at the moment. Im sure Ill need to bug you all for more things I dont understand

This link goes to a broad explanation which I wrote on another forum and intended to be read by people who were not engineers or applied physicists.

It should give you an insight into the "global collapse" AKA "collapse progression" of the twin towers.

http://www.rationalskepticism.org/c...-obligatory-9-11-thread-t515-680.html#p135852

There is (at least???) one slight technical error and the whole document suffers from no proper proof read but it is still readable.

 

[beachnut]

This link goes to a broad explanation which I wrote on another forum and intended to be read by people who were not engineers or applied physicists.

It should give you an insight into the "global collapse" AKA "collapse progression" of the twin towers.

http://www.rationalskepticism.org/c...-obligatory-9-11-thread-t515-680.html#p135852

There is (at least???) one slight technical error and the whole document suffers from no proper proof read but it is still readable.

You know what would make me happy? If something like this happened:

An investigation is done into the presence of the microspheres, it is found that someone was storing an exotic accerelant

What? Wow, there is a lot of woo there, ironic with a name of Rational Skepticism as the web site. How did all the woo get in?

That is a lot of woo.

 

[Dave Rogers]

Im genuinely curious about the speed at which all 3 building fell. (I know there was a little posted about WTC7). My knowledge of engineering or whatever topic it would be, is very limited so would somebody explain to me how a 92 story building can collapse at almost free fall speed?

It all depends on your definition of "almost".

But let's start from the beginning. Firstly, both of the twin towers were 110 storeys high, and WTC7 was 47 storeys high. This isn't nitpicking; you're talking about the details of the collapse, so it's a good idea to start from what those details really are.

The pancake theory the report is so fond of, would still mean it should have fallen at 92 seconds if 1floor = 1 second to collapse, or at best 46 secs if its 0.5 seconds per floor (if I've understood correctly).

Now, you have to understand that this paragraph is meaningless nonsense. Firstly, the NIST report doesn't propose any kind of "pancake theory"; it finds that the likely cause of collapse initiation was a combination of progressive core column failure due to creep, and eccentric loading due to pull-in on the perimeter columns, and it doesn't analyse collapse progression in detail at all. Secondly, no physically reasonable pancake collapse theory predicts a constant speed collapse, so the very idea of calculating a collapse rate in seconds per floor is quite groundless. And, thirdly, there's no particular reason, even if the idea made any sense, to choose either one second or half a second per floor; this form of analysis is commonly known as "pulling numbers out of your @$$".

How can 92 stories fall in under 10? I find it hard to believe that any collapse theory could explain a fall so quick.

It can't, because it didn't happen. The best collapse times measured are from a combination of video and seismic evidence, because the later stages of the collapse were obscured by dust and so cannot be observed. The actual value for both towers was somewhere in the region of 12-16 seconds, which is very much slower than the sub-9 second time for a freefall collapse through the same height.

Please dont jump down my throat like you have been with each other, I am neither conspiracist or debunker, i just dont know enough about things like this and I would like to find out

Mike Williams's 9/11 Myths site, in its current and previous versions, is a very good place to learn much of the basic information. In particular, as a starting point for understanding the collapse times, I can recommend Frank Greening's analysis, which answers most of the basic questions you've raised.

Dave

 

[aggle-rithm]

You don't have it quite right. Tall buildings are designed to resist very large lateral forces (the wind) The gravity loads are secondary and easier to resist. As a result a the building will fail from gravity long before it "topples"
The designers would have had to greatly increase the gravity carrying members, not the lateral ones .

Ah, I see.

I had heard that buildings will tend to fail when tilted at a certain angle, and jumped to conclusions about why that would be so. I stand corrected.

However, if the gravity carrying members are designed to transfer load straight downwards, and instead they find themselves at an angle, wouldn't that tend to make them fail?

 

[ladmo]

Some people do not comprehend models, so they attack them and people because they have delusions of CD. In a hopeless need to support their failed conspiracy theories, they lash out, failing to make a point, lost with their failed claims. 911 truth makes up statements of core-led collapse, explosive demolition, and offer no evidence, no engineering, nothing. 10th year of core-led explosive nonsense. Where is their evidence? Safe in their fantasy of 911. When will 911 truth sling some engineering to support their failed CD claims? Never. Publish their work? Never. Do anything more than make failed claims of CD? Never.

Beachnut... I have enjoyed your explanations, comments, and other sundries for the past year... in fact, your explanation of FDR information about the Pentagon was outstanding! What I find unusual in your banter with MT is the level of proof that you hold him to. Not being a part of this forum for as long as most have been, there may be peer written papers by other posters but I am not aware of them (again I have not been here for years) but you are holding MT to this high level.

I truly like this string of discussion and applaud everyone who backs up their information with statistics what I find derailing is the insistence of mentioning CD when I don't see it mentioned by MT. Again, there may be history between the 2 of you and the both of you go directly to the core of the matter (no pun intended) while skipping the preliminaries but for me, this core proposition is interesting.

 

[TruthersLie]

Beachnut... I have enjoyed your explanations, comments, and other sundries for the past year... in fact, your explanation of FDR information about the Pentagon was outstanding! What I find unusual in your banter with MT is the level of proof that you hold him to. Not being a part of this forum for as long as most have been, there may be peer written papers by other posters but I am not aware of them (again I have not been here for years) but you are holding MT to this high level.

I truly like this string of discussion and applaud everyone who backs up their information with statistics what I find derailing is the insistence of mentioning CD when I don't see it mentioned by MT. Again, there may be history between the 2 of you and the both of you go directly to the core of the matter (no pun intended) while skipping the preliminaries but for me, this core proposition is interesting.

Something you need to understand (like with your lack of understanding of what a FDR will withstand) is that there are ZERO peer reviewed engineering journal articles which state that NIST got anything wrong. There are ZERO peer reviewed engineering journal articles which state that BAZANT got anything wrong.

Truthers constantly run around saying that NIST is wrong it is sooooo easy to spot... But NOT ONE peer reviewed engineering journal article ANYWHERE IN THE WORLD, IN ANY LANGUAGE supports that.

So MT is trying to state that Bazant is wrong. Great. Get it published and through peer review and then come back and tell us about it.

ETA: as for the lack of seeing MT mention CD, go look up his ROOSD thread. The has some very good observations about the behavior of the collapse (which are different than what NIST said), but at the end he tries to back into the conclusion that CD would have brought down the towers, even though he doesn't mention it ANYWHERE in the actual article

 

[Animal]

Ah, I see.

I had heard that buildings will tend to fail when tilted at a certain angle, and jumped to conclusions about why that would be so. I stand corrected.

They will fail when the tilt gets to a certain angle.....because the gravity carrying members fail, not the lateral force members.

However, if the gravity carrying members are designed to transfer load straight downwards, and instead they find themselves at an angle, wouldn't that tend to make them fail?

Yes, to prevent that the building structure would have to be highly over designed WRT the gravity structures.

 

[ozeco41]

Beachnut... I have enjoyed your explanations, comments, and other sundries for the past year... in fact, your explanation of FDR information about the Pentagon was outstanding! What I find unusual in your banter with MT is the level of proof that you hold him to. Not being a part of this forum for as long as most have been, there may be peer written papers by other posters but I am not aware of them (again I have not been here for years) but you are holding MT to this high level.

I truly like this string of discussion and applaud everyone who backs up their information with statistics what I find derailing is the insistence of mentioning CD when I don't see it mentioned by MT. Again, there may be history between the 2 of you and the both of you go directly to the core of the matter (no pun intended) while skipping the preliminaries but for me, this core proposition is interesting.

Far too many people use "publish a peer reviewed paper" as an evasion. The test of MT's - and any one else's - claims is "Is the claim correct?" Many times when you see challenges for MT or another person to "get it peer reviewed published" the challenge is actually a code. The translated version of that bit of code speak is "I cannot rebut your argument - I agree with the mob that you are a truther - therefore I will pour scorn on your claims without the normal courtesy of putting forward reasoned argument".

The second issue you identify is the practice of making dishonest accusations against the truther by accusing him of something he has not said or something which is not in the context of current discussions.

I have said it several times but if a "known truther^TM" makes the claim that the sky is blue it is considered reasonable to deny that claim on the basis that the truther once mentioned CD on another forum, several years ago and in another context. The unstated rule or standard seems to be that in any discussion with a "known truther^TM" any claims by the truther are to be treated as false even if exactly the same claims are accepted mainstream truth. Note for example many derogatory comments directed at what MT calls "ROOSD" and which is pretty much the core of the mainstream explanation of the WTC1 and 2 global collapses. Except when MT says it it somehow becomes ridiculous.

 

[beachnut]

Beachnut... I have enjoyed your explanations, comments, and other sundries for the past year... in fact, your explanation of FDR information about the Pentagon was outstanding! What I find unusual in your banter with MT is the level of proof that you hold him to. Not being a part of this forum for as long as most have been, there may be peer written papers by other posters but I am not aware of them (again I have not been here for years) but you are holding MT to this high level.

I truly like this string of discussion and applaud everyone who backs up their information with statistics what I find derailing is the insistence of mentioning CD when I don't see it mentioned by MT. Again, there may be history between the 2 of you and the both of you go directly to the core of the matter (no pun intended) while skipping the preliminaries but for me, this core proposition is interesting.

Major Tom believes explosives or thermite destroyed the WTC complex. That is a delusion. He has no evidence, he makes up fake studies, leaves out the math and tries to back in CD.

Why would he mention CD now, we all know he is a CD pusher, he is trying to be subtle?

Are you trying to support explosives used on 911? The OP post failed.

Major Tom wants to give a pass to UBL and 19 terrorists, he can tell by looking at photos, bad guys did 911, and they were not the 19, the 19 who really did it.

These are just some of the factors which, when studied in depth, show that the supposed "gravity-driven collapse" is a mere illusion to mask an intentional act so barbaric, so inhumane and morally impoverished that the fabled characteristics of Satan come to mind. Major Tom

Major Tom is trying to get people to agree to his stuff, then he will break the CD delusions out as if you agreed to it, or some silly method these guys have now. He is afraid to say what he thinks. The gravity collapses we saw on 911 were illusions, says Major Tom.!

Major Tom looks at steel and says -

NO MECHANISM OF COLLAPSE, BESIDES CONTROLLED DEMOLITION WITH EXPLOSIVES, CAN EXPLAIN THIS PHENOMENA.

Silent explosives, he left that out, not sure what explosives he is going to use, or says were used, he is shy, he has to set you up to agree on points first, and then ...

Did you see the Twilight Zone episode about hell, and heaven - 911 truth is hell, where thinking for yourself is not desired, and having evidence is prohibited. Major Tom is sweet talking people to join him in the pit of 911 truth, where the truth is not shining. The OP is nonsense, ergo was upset he can't do physics, so he makes up stuff.

10th year, they peaked years ago with woo, now they never mention CD here, down deep they know it is nonsense. If you want to know what the covert truthers believe, go around the internet, and you can find they believe the Official Story is Fictional, or search Major Tom, and you find he is a CD claim truther, based on photos, and his eyes. Things they don't understand are signs of an inside job.

 

[Grizzly Bear]

Far too many people use "publish a peer reviewed paper" as an evasion. The test of MT's - and any one else's - claims is "Is the claim correct?" Many times when you see challenges for MT or another person to "get it peer reviewed published" the challenge is actually a code. The translated version of that bit of code speak is "I cannot rebut your argument - I agree with the mob that you are a truther - therefore I will pour scorn on your claims without the normal courtesy of putting forward reasoned argument".

Dunno if I totally agree with the latter but I do think the "publish to peer review" is overused. My biggest beef if anything is he's not clear on what he wants people to get out of his Bazant and NIST bashing. I'm referring to major_tom btw.

 

[beachnut]

Far too many people use "publish a peer reviewed paper" as an evasion. The test of MT's - and any one else's - claims is "Is the claim correct?" Many times when you see challenges for MT or another person to "get it peer reviewed published" the challenge is actually a code. The translated version of that bit of code speak is "I cannot rebut your argument - I agree with the mob that you are a truther - therefore I will pour scorn on your claims without the normal courtesy of putting forward reasoned argument".

The second issue you identify is the practice of making dishonest accusations against the truther by accusing him of something he has not said or something which is not in the context of current discussions.

I have said it several times but if a "known truther^TM" makes the claim that the sky is blue it is considered reasonable to deny that claim on the basis that the truther once mentioned CD on another forum, several years ago and in another context. The unstated rule or standard seems to be that in any discussion with a "known truther^TM" any claims by the truther are to be treated as false even if exactly the same claims are accepted mainstream truth. Note for example many derogatory comments directed at what MT calls "ROOSD" and which is pretty much the core of the mainstream explanation of the WTC1 and 2 global collapses. Except when MT says it it somehow becomes ridiculous.

Major Tom failed to back in CD. Publish his stuff, see how the conclusion of CD, silent ones work when you take his great work and publish it. What was his goal? Thesis? Conclusion? Fluff, missing math. I want them to publish, I want to see all of it published. Go ahead you see merit, the sky is blue for you and they say so, go ahead and miss the bottom line.

What merit does explosive demolition play in this thread, a thread based on a delusion ergo has based on lack of knowledge. Are you ready to publish this fantasy?

When 911 truth says the sky is blue, they get agreement, then they say you agree with the CD delusion, because you agree the sky is blue. They have delusions, you appease those who seek to spread anti-intellectual claptrap anyway they can, they fool you into thinking they are serious, and have something by repackaging other studies, they discover the sky is blue - wow, it is, Publish it.

They get stuff correct, when they connect the dots, or want to connect the dots, they come up with CD, or thermite, the inside job. They say the sky is blue, therefore CD did it. 10th year of failure for 911 truth, I want them to publish, be proud. If I thought 911 was an inside job, an thought I had it figured out, I would publish it. Why can't 911 truth.
They will not publish, what they have means nothing, goal free junk. They fail to rise to the challenge, they prefer implying lies of a inside job, a fringe few linger in fantasy of CD, imply lies, ...

Publish it, that is a challenge.

 

[ozeco41]

Dunno if I totally agree with the latter but I do think the "publish to peer review" is overused. My biggest beef if anything is he's not clear on what he wants people to get out of his Bazant and NIST bashing. I'm referring to major_tom btw.

I have challenged MT several times for bashing authorities including Bazant and NIST. It makes it very hard to discuss the point he tries to make when his posts seem to have the primary objective of bash whatever authority.

On the other side of the balance too many from 'debunker' side either explicitly or by inference accuse MT of claiming that NIST or Bazant are totally wrong. His responses do nothing to clear the argument. There are limitations as to where the various Bazant papers apply to the real world. MT doesn't always make it clear that those limitations are only portions of the overall Bazant picture. Then those opposing MT are rarely explicit and fair in the other direction. So too much black and whiting when the issues are shades of grey. Or possibly chequered patterns of black and white.

Hence my favourite little example of what would happen if a truther dared to claim 'the sky is blue'. I use it as a thought provoker.

 

[beachnut]

I... Hence my favourite little example of what would happen if a truther dared to claim 'the sky is blue'. I use it as a thought provoker.

That is 911 truth in a nut shell. 911 truth says the sky is blue, conclusion, WTC 7 was CD. That is the entire movement, no evidence for their claims, so they have to make the sky is blue statements to look legit as they add their tag-line of woo. Nothing wrong with holding their hands, they are not taking action, they are looking for the next sky is blue factoid to prefix to their next attempt at pushing woo. Why are they all shy, some deleting their early truth statements, as if a few are making the transition to reality.

Skip to the conclusion when it involves reality, the OP goes to explosive demolition delusion out of the box.