The 9/11 Forum

Sorry but the idea of attacking the (white) perimeter panel at the 78th floor at that late point in time appears at best unbelievable. At that point in time no one could have expected that that perimeter panels would have changed anything in the progress .
The better question is, what is the core doing? ... Why the floors above apparently smoothly bow inwards apparently without that heavy resistance or massive concrete dust... ? One part of the answer is pretty sure the elasticity of the white panel and the outward speed of the spring back cracking the floor. Another factor appears to be that the lower floors between core and perimeter pushing "outwards" while the panels were pulled inward by the panels above.
The black falling panel apparently came from the above the 85th floor and we may expect the upper edge of the bowing area up there. The question why there are those dust ejections at 78 but not at 79, 80, 81... apparently has to be answered by that area. 78 was the lower edge of the bowing.

The airplane damage might explain something too. At least apparently. (In the case of WTC1 the airplane damage plays no role for the direction of the tilting.)


I think we should try to go back from the effect to the cause. Right now we take the effect for a cause. The involved forced were above imagination. A flower sized puff of dust at the lowest edge of motion wasn't the initiation.

achimspok wrote:A flower sized puff of dust at the lowest edge of motion wasn't the initiation.

I don't think anyone is saying it is, however, determining the probable cause of each event will help greatly in defining the whole process. Each focussed ejecta certainly appears at odds with any natural mechanism I have considered so far, and for that reason are very worthy of as much of a tooth-comb as we can.

Am not sure about the pivot point you have. Will try and get around to a cross-check. Good format for presenting the model. Will extend to include non-horizontal split plane (as per http://www.youtube.com/watch?v=WFr3QeCzVgY). Spandrels will definitely be useful addition.

achimspok wrote:
Sorry but the idea of attacking the (white) perimeter panel at the 78th floor at that late point in time appears at best unbelievable. At that point in time no one could have expected that that perimeter panels would have changed anything in the progress .

Good drawing Achimspok, It shows well what I mean in my previous message. The initial attack has been done upper to the floor 78. The floor 83 should be the right one; it's a core columns junction’s floor.

Let me give some precisions:
- I am not sure on the rotation axis. It can not be so high, the red point moved eastward during the flipping. But I understand why you positioned it there; the breaking level on the west face went westward, so the rotation axis should be high. But the movement was not a simple rotation; there was also downward move. The mixing of both movements will create westward move of the west face. So it’s difficult to define any static rotation axis. But if we want to define any first one at the beginning of the movement, it could be around columns rows 900 & 1000 on floor 83.
- This image should be made three times to represent three positions of perimeter panels junctions. That should create three different behaviors of the perimeter panels and inward bowing.

achimspok wrote:The better question is, what is the core doing? ... Why the floors above apparently smoothly bow inwards apparently without that heavy resistance or massive concrete dust... ? One part of the answer is pretty sure the elasticity of the white panel and the outward speed of the spring back cracking the floor.

That eleasticity is true and clearly visible.

achimspok wrote: Another factor appears to be that the lower floors between core and perimeter pushing "outwards" while the panels were pulled inward by the panels above.

This is very small on floors around 78. But it could explain the falling upper panels.

achimspok wrote:The black falling panel apparently came from the above the 85th floor and we may expect the upper edge of the bowing area up there. The question why there are those dust ejections at 78 but not at 79, 80, 81... apparently has to be answered by that area. 78 was the lower edge of the bowing.

The ejections at F79 and F80 appears at the same time, as if they were synchronized. That means they were made by the same source explosion. That explosion could be the breaking of core columns at floor 80 inside the lift shafts.

achimspok wrote:
The airplane damage might explain something too. At least apparently. (In the case of WTC1 the airplane damage plays no role for the direction of the tilting.)

The plane impact on WTC1 was at the middle of the tower entering inside the core. The damage on the perimeter columns was symmetrical, except the entry hole of the plane. That’s why the tower collapsed almost symmetrically when the core columns were exploded.

achimspok wrote:
I think we should try to go back from the effect to the cause. Right now we take the effect for a cause. The involved forced were above imagination. A flower sized puff of dust at the lowest edge of motion wasn't the initiation.

That’s right.

Everyone must follow their own instincts.

Achimspok, you are a very good researcher. I think you just missed the boat in you last comments but we will disagree from time to time. That is fine.

This thread can move to the question of the core.

I'm going to form a private discussion on the 78th floor perimeter action witnessed. I cannot drop the subject of the behavior of the points along the 78th row in good conscience as the images seem to show a shock wave blowing columns outwards before the bolts break. If that is true, and people are confusing cause (shockwave) with effect (breaking bolts), you folks are walking past a huge opportunity.

Femr, OneWhiteEye, are you interested? There are a few other things I want to discuss with you in private.

Mehmetti, obviously no one wants to reply you, although I agree on the absence of ninjas.

This thread can move to the question of the core.

Thank you very much.

So does anyone have a working geometrical model for the WTC2 bowing?

I think that you should view this video:

http://www.youtube.com/watch?v=YoZY7lNRlSI

9:37 In the South Tower,a person on the 106th floor tells a dispatcher that floors below are beginning to collapse.

NYTimes, January 9, 2005, '102 Minutes':
"...Here is the moment at 9:52 a.m. when the south tower collapsed: 'The voices from the 105th floor, 20 stories above the top of the impact zone, grew more urgent. One woman called 911 and said the floor was collapsing. A moment later, a man called from 106 and said a floor below was collapsing. ..."

911 Commission Report p304:
"9:37, a civilian on the 106th floor of the South Tower reported to a 911 operator that a lower floor -the "90-something floor"- was collapsing."
This information was conveyed inaccurately by the 911 operator to an NYPD dispatcher... telling NYPD officers "the 106th floor is crumbling" at 9:52..."

NISTNCSTAR1-8 p37:
"9:41 am NYPD dispatcher advises units that floor 106 in WTC2 is collapsing...
9:51 am NYPD dispatcher advises that at WTC2, floor 106 is crumbling..."

Floor collapses before the buildings fell

"At 9:24, fire rescue received a call from a frightened man who said that the stairway had collapsed on the 105th floor of Tower Two. It would be an omen." - p. 641

"At 9:47, in a nearby office, a woman called fire rescue with an ominous message. The floor underneath her, she said, was beginning to collapse."

James Bamford, "Body of Secrets," (2002 update) p. 64

Major_Tom wrote:Everyone must follow their own instincts.

You too, Tom. And ...

Major_Tom wrote:If that is true, and people are confusing cause (shockwave) with effect (breaking bolts), you folks are walking past a huge opportunity.

That does not look like following your own instinct. If you follow your own instinct, you should tell what you think, regardless the situation.

I believe you are a good observer, you proved that in the past, and you are still proving it here; I had to review my opinion according to your questions. And that helps the knowledge, the investigation, the progress.

Sometimes,we all could make mistake and follow weak or imperfect theories. When we find more evidence contradicting our opinion, we must be able to change our opinion and open a new investigation field. I had to do that with the identification of the "spire" of WTC1; It was not easy to do, but when I checked all evidence and found that I was wrong I clearly changed my opinion. Finally I progressed with new evidence identifying the core.

When we all checked an evidence and agreed on it, that evidence becomes stronges, because it's cross-checked by many people.

I am not sure on the rotation axis. It can not be so high, the red point moved eastward during the flipping. But I understand why you positioned it there; the breaking level on the west face went westward, so the rotation axis should be high. But the movement was not a simple rotation; there was also downward move.

There was no downward movement but just rotation during the first a little more than 1 second. During that time the NE corner goes down and the NW corner goes upwards. So somewhere between the corners must be a point of neither up nor down movement.


Btw, I don't want to cut any discussion about any relevant point in this thread but I wanted to remind the position and time of the dust ejection just to see the events in relation to the whole thing.

Of course, the push/pull mechanism (floor slap between core and perimeter) at the 78th floor appears small in relation to the floors above but it seems that 78 is the first floor where the floor slap somehow resists the inward motion of the perimeter. Therefore we see a line of fine dust before the push/break shoots out that broccoli cloud.

achimspok wrote:

An initial rotoscope...

Summing shows static elements. Wouldn't call it pivot point exactly, but right hand side a few floors up...

achimspok wrote:There was no downward movement but just rotation during the first a little more than 1 second. During that time the NE corner goes down and the NW corner goes upwards. So somewhere between the corners must be a point of neither up nor down movement.

The fire arising in 81NW is created by the air moving due to the compression of the upper floors. There was probably a small fire inside the floor and the created air move (wind) brought some more oxygen and increased the fire. That’s natural.

For the upward moving, I preferred to watch again the original video.
http://www.youtube.com/watch?v=WFr3QeCzVgY
I can't tell that the NW corner went up. If it was getting up, the NW corner should be broken with an opening between the lower and upper parts. Instead, both lower and upper parts remain in touch and they went westward. That's only possible if there is compression on each part (lower and upper parts).

We can also see the breaking line, inside the north face, starting from 81-East and going to 83-West. That means during some time the 83-west remained intact while 81-East is falling. That shows the axis is on 83-West face!?

achimspok wrote:Of course, the push/pull mechanism (floor slap between core and perimeter) at the 78th floor appears small in relation to the floors above but it seems that 78 is the first floor where the floor slap somehow resists the inward motion of the perimeter. Therefore we see a line of fine dust before the push/break shoots out that broccoli cloud.

Yes, I see what you mean. Let’s look into:
- The fine dust ejection is before the bended bolted junction break.
- When the bolted junction is broken, the dust ejection increases immediately.
That does not mean the break is made by the dust ejection, this was there before the break. The break is made by the upper part compression and floor trusses downward pulling.

An overlay to confirm the rotoscope (as there would appear to be doubt)...

A bit more transparent...

Fade...

I'll stick the HD version on YT when I get a chance.

After watching the rotoscope for a while, and thinking about *pivots* I get the following impression...

a) The *effective* pivot point (the static point during rotation) appears to be right at the West face, several floors above the Eastward IZ level.

b) It is not really practical to consider that to be an actual structural pivot, but more the center of rotation. How would we rationalise that with respect to center of mass ?

c) There are a *lot* of upper North and South face elements towards the East face during the initial moments that *overlap* with seemingly intact lower North and South face elements. We should consider what happened within the overlap areas.

d) The rotation is not constant, but accelerates. The rotoscope does not yet take the acceleration into account, so there are elements of lag.

-*-

e) Such a Westerly centre of rotation implies to me that there was no core support throughout the entire depth of the core (from E to W), and that *failure* may have progressed from E to W.

f) Failure of the East face perimeter (and overlap areas) would be required in advance of such for the West face for the observed direction and centre of rotation to occur (by whatever means)

Interesting. I'd better get the rotoscope done over a longer time period, and from additional angles. I think it may be quite revealing.

That does not mean the break is made by the dust ejection, this was there before the break. The break is made by the upper part compression and floor trusses downward pulling.

Agree so far but my impression is that 78 do not pull but "try to resist" against the inward bowing. The panel "cut" into the edge causing little dust prior to break and so on...
One floor above the impression of any resisting element from inside is missing. (My impression.)

Axis: OK, apparently you place it at 88 and half the way between coreW and perimeterW. Funny, I found an older animation I made where I used 86 and the west face. All looking somehow pretty good just the onset of the "fall" might differ. For 86 and west face I got about 3.4 seconds without fall.


Hmm, no upwards move... may be. In my video it looks like the NW kink moves upwards and the columns get stretched or... but maybe once again a video compression issue?

What do you think about that?

achimspok wrote:Hmm, no upwards move... may be. In my video it looks like the NW kink moves upwards and the columns get stretched or... but maybe once again a video compression issue?

What do you think about that?

There does not appear to be any upwards motion of the west face split point, but possibly a little downwards. I can't imagine column stretch. More probably more complex 3D motion.

Column action: Possibly, yes. The action wouldn't be a pivot as such, but does give an impression of possible far west core action.

Any vertical (up or down) motion can be clarified by rotoscoping to another angle with different footage. Will get around to it.

((Glad the larger plain rotoscope images came in handy )

Really good. What about the 1000 row columns? We need an IB mapping of the east face.


For all points on the east face we need to know how much IB as a function of time.

We could really use a visual of how IB changes over time.



IB is a function of floor level, column number and time. IB=IB(f, c, t)


There must be a way to translate IB into some kind of structural sagging within the 1000 (and 900?) column rows.

Major_Tom wrote:We could really use a visual of how IB changes over time.

IB is a function of floor level, column number and time. IB=IB(f, c, t)


There must be a way to translate IB into some kind of structural sagging within the 1000 (and 900?) column rows.

I think it would be more productive to do it in terms of cap tilt angle and vertical drop.
Add, for WTC2, east and west *split* floor, relative to horizontal.
Not sure how else floor level would come into play. Same mechanics could be applied to many floors. Only thing that changes is column thickness (as long as we go in 3 floor increments)