Why Should the WTC Towers Suffer Complete Collapse?

Conservation of energy means the bulk of kinetic energy transitions to removing supports, and precludes the kinetic energy of gravity from producing free fall, in the direction of least resistance (no supports in the way).

All this is involved in conservation of energy - momentum, velocity weight, mass, and gravity. None of those factors can be left out, when determining exactly how two twin towers almost completely molecularly disintegrated all the way down, including the steel. The most abnormal of free fall conditions outside a vacuum. It was not done by nature, 767, or jet fuel. There is no precedant in documented history to prove it was.

Originally posted by OrionStars
All this is involved in conservation of energy - momentum, velocity weight, mass, and gravity.

IF I left out any of those factors please point out where and I'll see if I can fix the error.

In relation to precedents, it's true there are no precedents to such an event. In fact this IS the precedent for any future similar disaster.

reply to post by gottago
Many thanks for giving my ramblings fair consideration.

It does appear that we viewed some similar characteristics in the collapse, especially the way the distribution of debris in both cases showed a significant bias in the direction of initial impact which, to me at least, is not really surprising. The mechanism of the collapse was extremely chaotic where randomness rules in terms of outcomes yet we see a hint of order in it.

From pictures of the large multifloor open lobbies there was not that much material in them compared to the higher-up standard floor structure and a large part of that lower structure like wall sections were left still standing. How far into the sub-basement levels did that central falling mass penetrate and was it about 2-3 floors or more?

Also - were those lower floors (meaning entire load bearing structure) built to arrest 25% of the mass they normally carried when it strikes at 30+m/sec?




[edit on 30/1/2008 by Pilgrum]

[edit on 30/1/2008 by Pilgrum]

reply to post by Pilgrum


It's not really the question of the strength of the very lowest floors and their resistance to collapse, but where the core columns ended up. They didn't end up fallen about a stump core, or crushed upon a fallen core, as your scenario would predict. I do however think it is the way collapse should have proceeded logically, but empirically the debris field tells a different story.

reply to post by gottago

They didn't end up fallen about a stump core, or crushed upon a fallen core, as your scenario would predict.

Erm man.
There was steal all over the place. And the various bits of steel laying around wasn't marked as "I came from the core." or etc.
It seems to me that the core would have recieved a large percentage of the damage since it was for lack of a better term in the very center of the storm. And debris did collapse into the footprints aka underground parking areas. Why would there be a stub of the core?

Steel should not have had to identify itself. Anyone familiar with structural steel knows what it looks like, and where it is used in various locations. What people are looking at in photos, is primarily the outside steel perimeter walls and steel facade sections.

That is not inside structural steel for support, for the vast amount of steel pile-up people are looking at in photos. The outside was attached to the outside and it lost lost attachment, plus, was violently blown out from the pressure inside the twin towers, as they were being disintegrated before our very eyes in 10 seconds or less.

What people are seeing, in individual sections or sections still bolted and/or welded together, are these piled on top of one another:

911research.wtc7.net...

If people scroll down, they will see 3 story high sections of outside steel perimeter primary load support sections, of three tubes connected with spandrel plates. The trident/fork shaped tubes are the 3 story high steel facade sections, clad in aluminum for eye appeal and prevention of rust corrosion.

reply to post by OrionStars


The picture posted earlier of the alleged right before CD welded steel.
Those look like they'd be core supports to me partially based on what you said.
Even though I would have maintained that from the beginning.

reply to post by gottago
That's the point I was making with the relatively fixed volume zone of destruction (the 'bathtub'), all the excess material beyond its capacity was spilt over the edge of the walls so up to 80% of the total mass of the building ended up thrown outside the walls. The core appeared to be stripped of horizontal support and simply couldn't hold itself up with nothing to stabilise it so much of the core actually came down after the main destructive wave had gone through.

With the average compacted density of the towers at ~5T/m^3, the total 1,000,000 tons of both collapsed towers would amount to just 3m depth of material if spread over the 16 acre site they occupied and that's without any dust escaping or any underground floors (like sub-basements) collapsing.



[edit on 1/2/2008 by Pilgrum]

reply to post by Pilgrum


This may seem compelling in theory but it again, look at any picture of either collapse after the halfway point. There just wasn't much if any building there to drive the collapse and crush the lower core. It was being ejected and you find it strewn about the site after the dust clears.

There just wasn't that much core where the core once was. It's pretty much two divots. How did all that structure drive collapse of the massive lower core, then manage to throw itself out of the way? This is the basic flaw of the gravity-driven collapse theory--the building is crushing itself straight down, yet afterwards you don't find all the stuff that supposedly crushed the core to the sub-basements inside the footprint.

And the spires were curiously enough the weaker, inner part of the cores as well, not the outer longitudinal box columns, which is entirely anomalous. And you don't even have serious structure falling on wtc6 but you find the entire bldg hollowed out, with the rest pocked like Swiss cheese:




Really, study that debris field and it tells you quite a lot.

reply to post by gottago


Erm I see alot of steel laying around like matchsticks.
AND.
This photo is obviously while the clean up was underway.
When exactly?
People are moving stuff at that point its hard in pristine crime scene condition.



[edit on 1-2-2008 by WraothAscendant]

reply to post by WraothAscendant


I'm not sure if you understand how the towers were built? Not trying to be condescending but let me explain in simple terms.

The floors were attached to central core and outer walls. The central core ran all the way from bottom to top in 3 sections welded and bolted together. 47 massive 4-6" thick steel box columns with multiple cross bracing. Those huge pieces you see in short neatly cut lengths are central core columns (see pic bellow). Think of the floors like a record on a spindle. If the record was attached to the spindle and the attachments came loose allowing the record to fall what would happen to the spindle? Any idea?

What made the central core globally collapse down on itself? Can you explain what NIST failed to do?



How did they get cut so neatly?

Originally posted by gottago



Thank you for posting the photo. I am merely using the photo for in general clarification purposes. I do hope it is not a problem using it for that purpose, gottago.

What is primarily seen is the outside perimeter steel primary load bearing wall sections and steel facade sections. I see no recognizable steel, in the photo, from inside either twin tower. At least, not in the above photo. A great deal of granulation type debris is apparent, but no recoginizable steel from inside the twin towers.

reply to post by OrionStars


See the pieces of the outer skin?
Thats steel.
Those little stick looking things laying around and in the hole?
Those are steel as well.
Oh and the sky is blue.
And like I said before. That picture is hardly evidence of any sort except that they were in the process of clean up.


[edit on 2-2-2008 by WraothAscendant]

These photos were taken probly September 21.
I am sure alot sooner then the photo you are pointing to as evidence.
For example no obvious holes made by excavation of the site.
They did manage to clear out the roads though by then.

Methinks I spy a little of the core standing up here. (refering to a previous post by gottago)


And then there is another picture just to show the fubarness.



And here be me source.
Click here to see where Wraothie poo got the photos and more photos


[edit on 2-2-2008 by WraothAscendant]

[edit on 2-2-2008 by WraothAscendant]

I really don't know how anybody can seriously look at those pictures and believe office fires caused that.

Sry but it's just laughable. It insults my intelligence.

I'm really out of argument, we've said all there is to say. If you don't get it now you probably never will. You all failed to answer the key questions that makes the collapses impossible by the hypothesis you're spreading. You show pictures that just boggle the mind, and you want us to believe that office fires caused that massive amount of self destruction?

You still haven't explained how the collapses managed to continue collapsing at an accelerating speed. In other words they fell with no friction/resistance that should have been present. Do you understand why that is such an important point? Do you understand why NIST purposefully left that part of the collapses out of their hypothesis? You probably don't because it seems the de-bunkers don't even see it as part of the collapses at all, just because it's not in their precious NIST report (as explained to you at 9-11myths); the fallacy that global collapse was inevitable once initiated and so nothing beyond initiation matters.
If you believe that then you don't understand neither the NIST report, or basic physics. Both pretty important things to understand if you are going to argue for either side. Wouldn't you think?

Originally posted by ANOK
I'm not sure if you understand how the towers were built? Not trying to be condescending but let me explain in simple terms.

The floors were attached to central core and outer walls. The central core ran all the way from bottom to top in 3 sections welded and bolted together. 47 massive 4-6" thick steel box columns with multiple cross bracing. Those huge pieces you see in short neatly cut lengths are central core columns (see pic bellow). Think of the floors like a record on a spindle. If the record was attached to the spindle and the attachments came loose allowing the record to fall what would happen to the spindle? Any idea?

What made the central core globally collapse down on itself? Can you explain what NIST failed to do?



How did they get cut so neatly?

The record player spindle analogy is a good one but those spindles are one single piece, not a multitude of individual sections welded and bolted together. The reason those core columns appear so neatly cut is they were made that way and what we see are broken welds - you can see the depth of the welds quite clearly there. The column sections were massively strong particularly in compression but the overall assembly is only as strong as its weakest links.

I'm starting to think that those buildings didn't come down due to fire as a primary cause, more likely they suffered multiple fractured welds in absorbing the initial impact of the planes which allowed the fires (not intense enough to actually melt steel) to have just enough influence to bring about the initial collapse.




[edit on 2/2/2008 by Pilgrum]

reply to post by ANOK

No offense but here is what I read:
"Yadda yadda yadda yadda yadda gross understatement of a situation having to do with burning jet fuel. and the inherent damage of a fast large fast moving plane slamming into a building yadda yadda yadda yadda."
Followed and permiated with ever more ad hominem BS aimed at getting insult shots at me on the sly. And how many times are you going to tell me your going to stop any conversation with me anyway?

I am not talking about nor do I care much about the NIST report.
I go off what sounds logical to me.
I haven't even really bothered to look at the blasted thing.
I don't want to be told what to think I'd rather make observations for myself.
Which is rather like you except my observations go contrary to yours.

It seems to me you overestimate friction/resistance, especially when we are talking about the sheer weights involved.

And to quote myself on another thread.

And I figured now I would offer a thought on the fires.
Heat rises. The steel of those supports are getting hotter and hotter.
And those of course radiate their heat mostly up.
Into a very good insulator known as concrete which does take some of the heat but deflects a good amount of it back to the steel supports in turn making them stay really hot and getting hotter and closer to plasticy stage of melting metal. Which of course reduces the strength of the structure to stay up, which after a little bit gravity takes over and does what it does enthusiasticly which is pull things down. And that is coupled with the sheer weight we are talking about here.
And remember we still have the highly enthusiastic burning of the fires creating even more head that follows the above progression.
Jet fuel once burning is after all highly enthusiastic in said process.


Please note I don't mean the above description as an insult to anyone it just amused me at typing this to use cutesy wording.

I am like that at times. I love to amuse myself.
I mean no offense.

Otherwords the impact and damage put a hurting on the building and the fires put it over the edge.

But pilgrum's statements sound good too.

And heres a video made by Perdue for you.

Going to say they don't know physics?
Or going to call them liars?



Or shall we just agree to disagree, leave insults out of it, and drop it?

[edit on 2-2-2008 by WraothAscendant]

The first theory I saw that attempted to explain the collapse centred on the truss seats at the outer walls and the idea put forward was that there was sufficient heat from the fires to cause the seats to deform and let the trusses go. That was obviously bunk after a little investigation because the fires at the outer walls (only on a couple of floors and isolated locations) wasn't hot enough to cause that, also the truss seats on the fallen wall sections are remarkably undistorted. This should lead to the conclusion that the bolts sheared to let them go via one of two methods: either the walls were displaced outward with enough force to shear them OR the mass of falling material crushed the concrete and bowed the trusses inward with enough force to shear the bolts. The latter option fits the evidence of trusses twisted like pretzels best.

How much resistance?
What about if the core was already fractured and its collapse was a secondary effect of the concentrated mass going through the relatively weak individual floors shearing the outer wall connections and stripping much of the horizontal bracing from the core columns (it was still attached to the remains of the trusses and dampers)?

IE maybe the collapse didn't have to crush down the core or even the outer walls and they simply couldn't support themselves without the floor connections for stability, not to mention the lateral forces generated by that tumbling mass I estimated at around the 100,000 ton mark causing the torn spandrel connections etc.

So for resistance - what was the load rating of a single floor exclusive of the core and outer walls? Just the actual floor mass sitting on truss seats which consisted of trusses, dampers, corrugated metal sheet and 100mm of concrete. Obviously the mechanical floors were somewhat stronger but how many of those were there?

The pics kindly linked by WraothAscendant seem to show a majority of core sections on top of the rubble pile which indicates they came down after the bulk of the building.

Originally posted by WraothAscendant
Methinks I spy a little of the core standing up here. (refering to a previous post by gottago)

I have no idea if they are core supports or not. There are a few pieces of inside structural steel which can be seen. Where is the rest of it? Hundreds of thousands of tons of steel could not be hauled off by 9/21/2001. It took them about 2 years to haul it in by many different purchase orders. They are not going to haul off all that internal steel in 2 weeks or less.

It had to be cut down to haul off with standard tractor-trailer rigs, and that can take weeks if all the core units were still there on a natural collapse.. The core units were cast in Japan, by special order, because they were much longer and denser than most structural steel used in high rises. Japan had the only casting foundry capable of meeting all the specs of the core supports. One base core support alone, at the base, weighed up to 51 tons, and were 51' long. They also measured 54"x22"x 5".

911research.wtc7.net...

Fig 2. Tree columns are 51 ft long, weigh up to 51 tons.

Most of that steel is the outside perimeter walls and facade not internal steel. Photos appear of those, for proper identification, on the above website as well.

I can only guess, without physically examining the structural steel seen in the photo, they may be the core supports from the 107th to the 110th floor. Those could be tapered on the inside, because of the hat trusses and their design, at that level, to tie the perimeter wall and core together for more stability and durability on heavy lateral loads.

I can only further surmise this. The architect moved the weight away from the core supports, and balanced that against the hat truss weight for better balanced gravitational support, in order to assist the core at the extreme tops of both towers. The cores supports, at the highest top areas, may have been shorter than 51'. They have to be judged proportionally, as 3 stories high to what is seen of individual facade and perimeter wall sections. That is what each facade and perimeter wall frame measured - 3 stories for each section.

reply to post by OrionStars


Rrrrrrrrrrrriiiiiigggggggggggghhhhhhhhhhhhhhhtttttttttttttttttttttttttttt
You can no more surmise how they designed the building to hold its loads than you can tell how many people was in it at impact.
And btw.
There was lots of floors below ground filled with debris.
So much for molecular disintegration eh?

*shuts self up at this point to avoid what he is too tempted to say*