Rotation of the upper section before collapse

[Scott_Milner]

Total balderdash. Apparently I have to repeat (http://forums.randi.org/showthread.php?postid=5102308#post5102308) myself on this topic every month or two.

It's no surprise you need to repeat yourself, you don't understand the question. The upper section had angular momentum. At one point it stopped rotating. What force stopped the tilting of the massive block?

http://www.erichufschmid.net/TFC/img/TopOfSouthTowerBreaksOffAndExplodes.jpg

Do not hotlink images.

This section is clearly off axis and has reduced itself from the original size before the lower floors begin to descend. Clearly this is an asymetrical loading and should have fallen off throughout the 1000 feet of "crushing" if you say it had become disconnected.

Split from: Hardfire: Szamboti / Chandler / Mackey (http://forums.randi.org/showthread.php?t=147480)

[bill smith]

It's no surprise you need to repeat yourself, you don't understand the question. The upper section had angular momentum. At one point it stopped rotating. What force stopped the tilting of the massive block?

http://www.erichufschmid.net/TFC/img/TopOfSouthTowerBreaksOffAndExplodes.jpg

This section is clearly off axis and has reduced itself from the original size before the lower floors begin to descend. Clearly this is an asymetrical loading and should have fallen off throughout the 1000 feet of "crushing" if you say it had become disconnected.

Obviously it looks like all support was whipped away from undeneath the block allowing it to descend frozen in it's last position of rotation.

Although I don't know if this video does not put a spanner in those works...

http://video.google.com/videoplay?docid=-1615521411849861778

[funk de fino]

It's no surprise you need to repeat yourself, you don't understand the question. The upper section had angular momentum. At one point it stopped rotating. What force stopped the tilting of the massive block?

http://www.erichufschmid.net/TFC/img/TopOfSouthTowerBreaksOffAndExplodes.jpg

This section is clearly off axis and has reduced itself from the original size before the lower floors begin to descend. Clearly this is an asymetrical loading and should have fallen off throughout the 1000 feet of "crushing" if you say it had become disconnected.

If you had a large seesaw with a high fulcrum point which had a heavy person on one side. The seesaw would tip towards the heavy person.

What would happen if you removed the fulcrum point or it collapsed? Would the seesaw continue tipping or would it fall straight down due to gravity?

[Scott_Milner]

That video really doesn't tell us much? If what you say is true about the frozen rotation, where is the 30 story section of the tower that should have been craddled down to the ground at 1g?

[Scott_Milner]

If you had a large seesaw with a high fulcrum point which had a heavy person on one side. The seesaw would tip towards the heavy person.

What would happen if you removed the fulcrum point or it collapsed? Would the seesaw continue tipping or would it fall straight down due to gravity?


The seesaw would rotate until the perpendicular to the ground and continue to descend (unless the heavy person fell off prior to...). How is this similar to the south tower?

[funk de fino]

The seesaw would rotate until the perpendicular to the ground and continue to descend (unless the heavy person fell off prior to...). How is this similar to the south tower?

Are you insane? The support for the seesaw is gone, there is no fulcrum. What is acting on the two guys on it? Will it continue to rotate?

[bill smith]

That video really doesn't tell us much? If what you say is true about the frozen rotation, where is the 30 story section of the tower that should have been craddled down to the ground at 1g?

Well it obviously must have passed at 1g through the remaining core (lots and lots of core) as we see in the video . Do you have another suggestion ?

[Slayhamlet]

Well it obviously must have passed at 1g through the remaining core (lots and lots of core) as we see in the video . Do you have another suggestion ?

Bill, just shut up. Even your fellow Truthers know you have no idea what the hell you're talking about.

[TruthersLie]

It's no surprise you need to repeat yourself, you don't understand the question. The upper section had angular momentum. At one point it stopped rotating. What force stopped the tilting of the massive block?

http://www.erichufschmid.net/TFC/img/TopOfSouthTowerBreaksOffAndExplodes.jpg

This section is clearly off axis and has reduced itself from the original size before the lower floors begin to descend. Clearly this is an asymetrical loading and should have fallen off throughout the 1000 feet of "crushing" if you say it had become disconnected.

1. the section is off axis because of the rotation
2. It has not been "reduced" from the original size. This was taken 3 to 4 seconds into the collapse. So it is already collapsing.

the top of the building was NOT ONE SOLID piece like a tree.. it was hundreds of thousands of connections which were getting destroyed as the building collapsed. Because they were individual connections it would NOT act like a tree and fall over and off the building. It was collapsing straight down.

Where was the fulcrum? What happens when the fulcrum is destroyed? does it keep rotating?

[Hokulele]

That video really doesn't tell us much? If what you say is true about the frozen rotation, where is the 30 story section of the tower that should have been craddled down to the ground at 1g?


??

[Scott_Milner]

If you had a large seesaw with a high fulcrum point which had a heavy person on one side. The seesaw would tip towards the heavy person.

What would happen if you removed the fulcrum point or it collapsed? Would the seesaw continue tipping or would it fall straight down due to gravity?

Are you insane? The support for the seesaw is gone, there is no fulcrum. What is acting on the two guys on it? Will it continue to rotate?

I'm insane? According to you, if there was a heavy person on one side of the see-saw it would tip toward the heavy person. If the fulcrum is removed and the see-saw is falling through air, you want us to believe it will not continue to rotate until the heaviest load (person) is aligned in the direction (plane) of free-fall motion?

[Scott_Milner]

1. the section is off axis because of the rotation

Yes, this is obvious.

2. It has not been "reduced" from the original size. This was taken 3 to 4 seconds into the collapse. So it is already collapsing.

The original section of floors above the impact hole accounted for approximately 1/3 of the tower.

the top of the building was NOT ONE SOLID piece like a tree.. it was hundreds of thousands of connections which were getting destroyed as the building collapsed. Because they were individual connections it would NOT act like a tree and fall over and off the building. It was collapsing straight down.

You are contradicting yourself. The upper section first began to rotate. It then change momentum suddenly. It was NOT collapsing straight down. Please review the video and still photo evidence.

Where was the fulcrum? What happens when the fulcrum is destroyed? does it keep rotating?

See above.

[Scott_Milner]

??

Sorry, it was meant to imply "at the acceleration of gravity".

[Hokulele]

Sorry, it was meant to imply "at the acceleration of gravity".


That isn't an improvement.

[funk de fino]

I'm insane? According to you, if there was a heavy person on one side of the see-saw it would tip toward the heavy person. If the fulcrum is removed and the see-saw is falling through air, you want us to believe it will not continue to rotate until the heaviest load (person) is aligned in the direction (plane) of free-fall motion?

You do not have to believe it but it is true. The rotation will not continue.

The gravity will act straight down on everything, they will all fall straight down.

What if a heavy person and a slightly lighter person jumped off the ESB the same time. Who would hit the ground first?

Galileo.

[Scott_Milner]

You do not have to believe it but it is true. The rotation will not continue.

The gravity will act straight down on everything, they will all fall straight down.

What if a heavy person and a slightly lighter person jumped off the ESB the same time. Who would hit the ground first?

Galileo.

Well, now you've changed the context. I agree with your latest statement, however your original question asked what would happen if the fulcrum was removed from the see-saw with a heavier man on one side (IE: would it continue tipping).

If the object is in motion and rotating, it will not stop rotating because you simply remove the fulcrum. An external force will be required to stop the rotating object once the fulcrum is removed. Have we met on the same page now?

[Edx]

Well, now you've changed the context. I agree with your latest statement, however your original question asked what would happen if the fulcrum was removed from the see-saw with a heavier man on one side (IE: would it continue tipping).

If the object is in motion and rotating, it will not stop rotating because you simply remove the fulcrum. An external force will be required to stop the rotating object once the fulcrum is removed. Have we met on the same page now?

You know Ive always wanted to know... what do truthers think is happening to the top section?

Ive heard some say it was blown up with explosives, which of course cant be true since theres no explosion sounds, blast waves or people that suffering from blast injuries.

So the only thing it can be is this nano thermite stuff. So how does that relate to the behaviour of the top section?

[funk de fino]

Well, now you've changed the context. I agree with your latest statement, however your original question asked what would happen if the fulcrum was removed from the see-saw with a heavier man on one side (IE: would it continue tipping).

If the object is in motion and rotating, it will not stop rotating because you simply remove the fulcrum. An external force will be required to stop the rotating object once the fulcrum is removed. Have we met on the same page now?

No, I never changed anything. I said remove the fulcrum and what happens to the rotation. The rotation will not continue because gravity will "push" everything straight down. There is nothing for the seesaw or the men to rotate around. The only reason they rotated before was because of the imbalance and the affect of the vertical gravity around the fulcrum point. It was not a horizontal force. The external force is gravity pushing straight down, it will overide any rotation which has a horizontal component. It's a very simple concept to visualize.

You are not in the same library, never mind the same page.

[triforcharity]

I'm insane? According to you, if there was a heavy person on one side of the see-saw it would tip toward the heavy person. If the fulcrum is removed and the see-saw is falling through air, you want us to believe it will not continue to rotate until the heaviest load (person) is aligned in the direction (plane) of free-fall motion?

Yes, that is correct. You're learning!!

[Grizzly Bear]

Well, now you've changed the context. I agree with your latest statement, however your original question asked what would happen if the fulcrum was removed from the see-saw with a heavier man on one side (IE: would it continue tipping).

If the object is in motion and rotating, it will not stop rotating because you simply remove the fulcrum. An external force will be required to stop the rotating object once the fulcrum is removed. Have we met on the same page now?

Hi, are you familiar with drawing force diagrams? Would you mind drawing one showing the vector forces in diagram format? I think it'll help you understand the reason for the vertical drop. At the very least it'll give readers here a basis on which to help you out in understanding it.

[Furcifer]

I'm not sure if you two are on the same page or not. The upper section would have had some angular momentum imparted during the tilt. Like a peanut butter sandwhich falling off a table ;) Unlike the table, the lower section gave way and the exterior wall stopped the rotation of the upper section (among other things).
I think one of you is talking rotation whike the other is thinking trajectory.

[R.Mackey]

It's no surprise you need to repeat yourself, you don't understand the question. The upper section had angular momentum. At one point it stopped rotating. What force stopped the tilting of the massive block?

I understood the question perfectly. The answer is that your assumptions are wrong. The upper section never stopped rotating.

As I explained in my whitepaper, however, which you obviously did not or cannot read, once the upper portion is loose, there is a restoring torque. This is because the tilt means that, as the upper block descends, it hits more of the lower floors on the down-tilted side. This should be obvious -- the down-tilted corner has fallen farther. If the block continues to rotate, this disparity will increase.

Conservation of momentum dictates that, since it comes in contact with more stationary mass, there is a net force on the downward corner that opposes its direction of rotation. Again, it did not stop rotating, but this is the force that slows the rotation, and it's totally normal.

This section is clearly off axis and has reduced itself from the original size before the lower floors begin to descend. Clearly this is an asymetrical loading and should have fallen off throughout the 1000 feet of "crushing" if you say it had become disconnected.

Impossible. It cannot "fall off" without a lateral force. There can be no lateral force unless the lower portion actually survives the impact. Calculations leave no doubt that it cannot.

That lateral force, again, worked out in my whitepaper, is equal to a minimum of roughly 65 million Newtons, or twice the liftoff thrust of the Space Shuttle. The lower portion cannot provide such an enormous force, and the upper portion would not survive if such a force was applied. I cover this on page 104 of the paper.

This is old, readily debunked crap, and it has nothing to do with the debate. Further discussion is off-topic, particularly as you do not appear able to even absorb what you see in a video correctly.

[Scott_Milner]

I understood the question perfectly. The answer is that your assumptions are wrong. The upper section never stopped rotating.
Interesting that there are two points of view within this thread. One person thinks the upper section didn't stop rotating; the other says the upper section stopped rotating while incorrectly quoting Galileo!
I suppose if I remove the fulcrum from my rotating bicycle tire that it will simply stop spinning and fall to the ground? It's amazing how basic physics is misapplied when discussing the towers (and other events of 9/11).
Impossible. It cannot "fall off" without a lateral force. There can be no lateral force unless the lower portion actually survives the impact. Calculations leave no doubt that it cannot.
This is old, readily debunked crap, and it has nothing to do with the debate. Further discussion is off-topic, particularly as you do not appear able to even absorb what you see in a video correctly.
You would like me to review the video to support your blinded version of what happened? I see how this works. As you can see in the photo I linked, the upper block has been reduced to ½ of the original size. The roof line is as long as the exposed facing side, yet the lower floors retain the same dimensions as the top end whittles itself away. You may want to reference the stop frame photos at 911research.net to see proof of this.
As someone pointed out, my photo link was taken about 3-4 seconds into the collapse. This means the top section lost 50% of its size with approximately 1000 feet left to “crush”. How does the upper section manage to crush 47 core columns and 200+ perimeter columns as it rotates off axis? One side of the building is experiencing compression, while the other side is feeling reduced loading. How do all four sides destruct at an equal pace for nearly a quarter mile with a 23 degree tilt of floors hanging off the side? Your theory hardly makes any sense, and certainly does not follow any video/photo evidence.
It may be wise for your little group to get together and agree on what’s happening. If nothing else, it will make your ‘story’ more believable...even for a short period of time. Find someone with a valid/certification in architecture/engineering to review your white paper before publishing.

[Hokulele]

I suppose if I remove the fulcrum from my rotating bicycle tire that it will simply stop spinning and fall to the ground?


That would be half right.

[TruthersLie]

Interesting that there are two points of view within this thread. One person thinks the upper section didn't stop rotating; the other says the upper section stopped rotating while incorrectly quoting Galileo!
I suppose if I remove the fulcrum from my rotating bicycle tire that it will simply stop spinning and fall to the ground? It's amazing how basic physics is misapplied when discussing the towers (and other events of 9/11).

You would like me to review the video to support your blinded version of what happened? I see how this works. As you can see in the photo I linked, the upper block has been reduced to ½ of the original size. The roof line is as long as the exposed facing side, yet the lower floors retain the same dimensions as the top end whittles itself away. You may want to reference the stop frame photos at 911research.net to see proof of this.
As someone pointed out, my photo link was taken about 3-4 seconds into the collapse. This means the top section lost 50% of its size with approximately 1000 feet left to “crush”. How does the upper section manage to crush 47 core columns and 200+ perimeter columns as it rotates off axis? One side of the building is experiencing compression, while the other side is feeling reduced loading. How do all four sides destruct at an equal pace for nearly a quarter mile with a 23 degree tilt of floors hanging off the side? Your theory hardly makes any sense, and certainly does not follow any video/photo evidence.
It may be wise for your little group to get together and agree on what’s happening. If nothing else, it will make your ‘story’ more believable...even for a short period of time. Find someone with a valid/certification in architecture/engineering to review your white paper before publishing.

so which sock are you? Hmmmm....

How does it lose 50% of its size when it is FALLING down towards the ground? Of course it is going to be "smaller" relatively because it is MOVING.

dur.

You have made the claim that no one has proved it, and you are wrong. Thank you for playing we have some nice parting gifts.

[Scott_Milner]

How does it lose 50% of its size when it is FALLING down towards the ground? Of course it is going to be "smaller" relatively because it is MOVING.

It's going to be smaller, relatively because it is MOVING? I'm sorry, I don't understand your logic/analogy.

As for the size, why don't you look up the length of the upper floors from above the impact hole and then compare it to the photo I linked earlier? If I'm not mistaken the width of the Towers were 207 feet? About 1362 feet tall?

Approximately 12 feet per floor. 78th floor lower impact hole. Upper block of floors should measure roughly 380 feet tall. What happened to it? See the following link and photos. Try to explain the evidence as shown:

http://doujibar.ganriki.net/english/e-wtc2-analysis/st-upper-rotation.jpg

http://doujibar.ganriki.net/english/e-wtc2_g0/wtc2-upperNE1.jpg

Source:

http://images.google.ca/imgres?imgurl=http://doujibar.ganriki.net/english/e-wtc2-analysis/st-upper-rotation.jpg&imgrefurl=http://doujibar.ganriki.net/english/e-01b-wtc2upperfloors-1.html&usg=__rbygp71CCW-nTlvSqUdeq78_amE=&h=393&w=287&sz=17&hl=en&start=218&um=1&tbnid=nYWUSDPp0ZjqvM:&tbnh=124&tbnw=91&prev=/images%3Fq%3DSouth%2Btower%2Bcollapse%26ndsp%3D18% 26hl%3Den%26rlz%3D1R2GGLL_enCA330%26sa%3DN%26start %3D216%26um%3D1

[beachnut]

...
Approximately 12 feet per floor. 78th floor lower impact hole. Upper block of floors should measure roughly 380 feet tall. What happened to it? ...
It fell. Easy question.
It may be a gravity collapse (gravity is the main source of energy for all CD BTW) of a tall building is not in your skill set.
8 years and you could have had a PhD in structural engineering and all you did was make up delusions. If I was as bad at this as you are I would go to college and get a degree that is useful to clear up your delusions on 911.

I did not see any explosions; does your delusion require explosives or moronic thermite?

http://doujibar.ganriki.net/english/e-01b-wtc2upperfloors-1.html That was one really stupid web site. Wowzer! How do you find such nonsense?

Which falls faster, the big guy on the seesaw, or the little guy? You have no friends in engineering or physics?

[TruthersLie]

It's going to be smaller, relatively because it is MOVING? I'm sorry, I don't understand your logic/analogy.


You keep saying 50% of it disappeared. Well since the photo was taken 3 to 4 seconds AFTER the collapse started, the upper portion was MOVING downwards. That would explain why it appears that "half of it is missing." Becaue it is moving you cannot say that "half of it is missing" because it is in the debris cloud and cannot be seen.


As for the size, why don't you look up the length of the upper floors from above the impact hole and then compare it to the photo I linked earlier? If I'm not mistaken the width of the Towers were 207 feet? About 1362 feet tall?

Approximately 12 feet per floor. 78th floor lower impact hole. Upper block of floors should measure roughly 380 feet tall. What happened to it? See the following link and photos. Try to explain the evidence as shown:


I am rather familiar with the dimension and sizes of the wtc towers. It has nothing to do with your BS about how it should fall over and off of the building.

you keep trying to say that it would keep rotating, but why would it? The fulcrum is destroyed within seconds of the start of the collapse, and the top part of the towers was NOT a solid object, but made up of hundreds of thousands of individual parts which would a. break and buckle under the impact, and b. impart a counter rotation when the lower corner struck the floor below.


http://doujibar.ganriki.net/english/e-wtc2-analysis/st-upper-rotation.jpg

http://doujibar.ganriki.net/english/e-wtc2_g0/wtc2-upperNE1.jpg


Sorry, I live in the UAE, and those images are blocked for some reason. Try to find another location of the same image, and I'd be happy to look at them.
Of course you could 5 minutes of real research and find that your questions have been answered in one of the 75 peer reviewed engineering journal articles out there which discusses the collapse...

(on an aside.. how many have you twoofs managed to get published in real journals again?)

Do not make sock puppet accusations in thread.

[MikeW]

Sorry, I live in the UAE, and those images are blocked for some reason.
It's not you (or the UAE), the site prevents hotlinking.

To bypass this in IE, right-click a link and select Copy Shortcut, then open a new tab, paste the link into the address bar, and press Enter. You're not following a link embedded in another page & so the image will be displayed.

[TruthersLie]

http://doujibar.ganriki.net/english/e-wtc2-analysis/st-upper-rotation.jpg

http://doujibar.ganriki.net/english/e-wtc2_g0/wtc2-upperNE1.jpg



The evidence from low res photographs at a distance filled with smoke which obscures the view?

It is amazing that you will actually try to take it as evidence. It is almost as bad as the stuff by ace baker or the no planers.

[Scott_Milner]

It fell. Easy question.
It may be a gravity collapse (gravity is the main source of energy for all CD BTW) of a tall building is not in your skill set. <snip>
Which falls faster, the big guy on the seesaw, or the little guy? You have no friends in engineering or physics?

Sadly, we've already covered the fact that both men would fall at the same rate it falling from a motionless stand point. What you and the other fellow fail to realize is that once in motion on the see-saw, the tilting will continue if the fulcrum is removed. Perhaps you can envision an aircraft propeller letting loose once rotating: it will not simply stop rotating and fall toward Earth after letting go from the shaft. Hopefully you understand this simple concept as I'm not about to teach basic physics to some kids named, "Beachnut" and "Funk de Fino".

You should also study the photos linked in my previous post as "It fell" doesn't explain how the upper section breaks apart before the 77th floor (and lower) begin to crumble.

[Scott_Milner]

You keep saying 50% of it disappeared. Well since the photo was taken 3 to 4 seconds AFTER the collapse started, the upper portion was MOVING downwards. That would explain why it appears that "half of it is missing." Becaue it is moving you cannot say that "half of it is missing" because it is in the debris cloud and cannot be seen.

There are several photo angles and video angles of this collapse which show the upper section tilting and the lower portion of the tower intact. Use the roof line to measure the length of the west and east walls as the top begins to rotate. The west wall should remain nearly double the length of the roof line as this side is leaning away from the tower and is not crushing onto the lower section.

[Sam.I.Am]

It's going to be smaller, relatively because it is MOVING? I'm sorry, I don't understand your logic/analogy.

As for the size, why don't you look up the length of the upper floors from above the impact hole and then compare it to the photo I linked earlier? If I'm not mistaken the width of the Towers were 207 feet? About 1362 feet tall?

Approximately 12 feet per floor. 78th floor lower impact hole. Upper block of floors should measure roughly 380 feet tall. What happened to it? See the following link and photos. Try to explain the evidence as shown:

Ok, I'll give it a shot, in layman's terms, because that's what I am. The people with P.E. and S.E. after their name can (and probably will) correct me if I'm wrong.

There was a simultaneous crush down on the lower section and a crush up on the upper section. If we assume that both sections failed at the same rate, then for every lower floor crushed down, an upper floor would similarly be crushed up. So, assuming this, the mass of the upper block will shrink but the total mass of the combined crushed floors from that now mangled (and smaller) block remains relatively the same (the difference being the ejected dust and whatnot from pulverized materials inside the buildings). Additionally the crushed down floors add to the mass of the original downward falling mass. You can lose structure but retain mass. I think that this is where you disconnect.

Additionally, and I'm being conservative here, about 1/2 of the perimeter columns of the upper block, in addition to the floors content, fell inside of the footprint of the buildings. No one floor could support that type of dynamic loading, not even the mechanical floors. I think that even a static load of that weight would overload the structure to the point of failure.

In summary: I think that even an optimal ten foot story drop, (less than your 12 foot floor) made it impossible for the buildings to stand. Each failure of the floors compounded the next by at least a factor of 0.4.

[funk de fino]

Interesting that there are two points of view within this thread. One person thinks the upper section didn't stop rotating; the other says the upper section stopped rotating while incorrectly quoting Galileo!
I suppose if I remove the fulcrum from my rotating bicycle tire that it will simply stop spinning and fall to the ground? It's amazing how basic physics is misapplied when discussing the towers (and other events of 9/11).

Its obvious from your reply you do not understand basic physics. My example was a simple analogy to explain something that you were blinded to.

[twinstead]

Ok, I'll give it a shot, in layman's terms, because that's what I am. The people with P.E. and S.E. after their name can (and probably will) correct me if I'm wrong.

There was a simultaneous crush down on the lower section and a crush up on the upper section. If we assume that both sections failed at the same rate, then for every lower floor crushed down, an upper floor would similarly be crushed up. So, assuming this, the mass of the upper block will shrink but the total mass of the combined crushed floors from that now mangled (and smaller) block remains relatively the same (the difference being the ejected dust and whatnot from pulverized materials inside the buildings). Additionally the crushed down floors add to the mass of the original downward falling mass. You can lose structure but retain mass. I think that this is where you disconnect.

Additionally, and I'm being conservative here, about 1/2 of the perimeter columns of the upper block, in addition to the floors content, fell inside of the footprint of the buildings. No one floor could support that type of dynamic loading, not even the mechanical floors. I think that even a static load of that weight would overload the structure to the point of failure.

In summary: I think that even an optimal ten foot story drop, (less than your 12 foot floor) made it impossible for the buildings to stand. Each failure of the floors compounded the next by at least a factor of 0.4.

that's pretty much the way this layman understands it too. I'd be open for any corrections, though. It's all about learning to me.

[funk de fino]

Sadly, we've already covered the fact that both men would fall at the same rate it falling from a motionless stand point. What you and the other fellow fail to realize is that once in motion on the see-saw, the tilting will continue if the fulcrum is removed. Perhaps you can envision an aircraft propeller letting loose once rotating: it will not simply stop rotating and fall toward Earth after letting go from the shaft. Hopefully you understand this simple concept as I'm not about to teach basic physics to some kids named, "Beachnut" and "Funk de Fino".

Funny you call us kids!!

[funk de fino]

How does the upper section manage to crush 47 core columns and 200+ perimeter columns as it rotates off axis?

It did not have to, that is the whole point.

[newton3376]

Sorry, it was meant to imply "at the acceleration of gravity".

Please tell me that you aren't an engineer or scientist.....

[BasqueArch]

<snip> How does the upper section manage to crush 47 core columns and 200+ perimeter columns as it rotates off axis? One side of the building is experiencing compression, while the other side is feeling reduced loading. <snip>

WTC1,2. The perimeter wall collapses. The top tilts towards the collapsing wall. This introduces torque to the remaining columns at the failed floor, a horizontal opposing force to the top and bottom of columns. One other perimeter wall has been largely severed by the plane, the remainder of the columns are either severed, bent, buckled, fire damaged and with increasing loading from progressively failing columns. The columns at or near the collapsing floor fail by horizontal shearing, not vertical buckling.

Due to the displaced tilt of the upper block, the columns above hit not the columns below, but the thin slabs below. As the slabs pancake to the ground, the perimeter and core columns topple.

http://911review.com/coverup/fantasy/imgs/figure4.gif
From Bazant - Fig. 4. Scenario of tilting of upper part of building ~South Tower - showing horizontal shear forces and displacement of upper and lower columns.

From Bazant’s first paper.
http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

[rwguinn]

I'm not sure this is on-topic, but the rotation is an issue, so we'll carry on.
The rotation begins as one side fails first. the CG of the upper block of the building has moved laterally a small amount, represented by z*sin(alpha), where z is the vertical distance from the failure point to the CG of the block, and alpha is the angle of tilt measured from the vertical axis.
For the upper block (UB) to TOPPLE, the CG must move outside the footprint of the block, which for practical purposed, is about a 100 foot distance. This is the equivalent of about 8-9 stories of the building. That would require about a 90 degree tilt, which everyone can likely agree did not happen, nor could it happen without a failure of the support structure on the still-attacjed side.
When that failure (of the non-damaged by aircraft and fire side of the building) occurred, the rotation did NOT STOP-it simply transferred to a rotation about the CG (This is an over-simplification, but accurate enough) as opposed to a rotation about the fulcrum point, and the Center-of gravity began to fall straight down, in accordance with the Laws of Physics. The rotation contributed its angular momentum to the lower block, increasing the forces on that side so that the total force was not just due to g, but to g+dv(angular)/dt. That angular velocity would also contribute to flinging chunks of building away from the foorprint

[Furcifer]

When that failure (of the non-damaged by aircraft and fire side of the building) occurred, the rotation did NOT STOP-it simply transferred to a rotation about the CG (This is an over-simplification, but accurate enough) as opposed to a rotation about the fulcrum point, and the Center-of gravity began to fall straight down, in accordance with the Laws of Physics.

I'm not so sure this is a supported statement. If memory serves, at one point the upper section tilts, begins to fall with very little angular momentum and then impacts the South? wall. At which point the upper section ceases to rotate and almost reverses direction (angular). Or at least appears to.

While there is no argument about the upper sections CG (or CM, we like to us CM, it's a physics thing ;) ) not having enough momentum to carry itself outside the footprint and topple, there is an issue with the CG of the upper section moving outside the "footprint" of the core.

This is no doubt debatable. I think there is sufficient obstruction by the debris to make a case either way. In my mind, based on the video evidence, I would lean towards the rotation of the upper section stopping at some point during the collapse.

Why? Because if the upper section did not stop rotating, it would have picked up angular momentum during the collapse. If it had, there is no case for the argument that the upper section remained intact. It would have simply pin wheeled out of control. Its own angular momentum responsible for its demise.

I hesitate to mention this for fear that somebody misconstrues it as evidence that the collapse didn't happen "naturally". Ultimately the collapse happened as a result of the damage incurred by the collision of planes carrying numerous lives, and not as a result of "thermite" or some of such nonsense.

[Scott_Milner]

Unfortunately, Bazant can't interpret video/photo evidence any better than Mackey can. The idea that the upper section would rotate while being connected by several core and perimeter columns is quite a fantasy, and totally contradicts the video and photo evidence.

Notice the upper block has moved off center and cannot possibly 'rotate' over the core of the tower. The section sticking out over the edge of the tower by approximately 100 feet has nothing below it and nothing above it. The two sections are not longer aligned, yet the upper block disappears.
http://www.erichufschmid.net/TFC/img/TopOfSouthTowerBreaksOffAndExplodes.jpg

http://911review.com/coverup/fantasy/imgs/figure4.gif

Do not hotlink images.

Bazant and Mackey have no clue, and their papers are good for about one thing...not even the collapse initation follows the tipping pattern of Bazant's diagram.

[R.Mackey]

Do you know any trigonometry, Scott?

If so, here's a problem for you: The Towers were 64 meters wide. The upper block of WTC 1 was about 12 or 13 stories, call it 40 meters. (It's actually a bit less, but you need all the help you can get.)

How much rotation is needed before it can topple?

Do you see this much rotation?

If you need help, look at pages 250-254 of my whitepaper.

[TruthersLie]

Unfortunately, Bazant can't interpret video/photo evidence any better than Mackey can. The idea that the upper section would rotate while being connected by several core and perimeter columns is quite a fantasy, and totally contradicts the video and photo evidence.

Notice the upper block has moved off center and cannot possibly 'rotate' over the core of the tower. The section sticking out over the edge of the tower by approximately 100 feet has nothing below it and nothing above it. The two sections are not longer aligned, yet the upper block disappears.
http://www.erichufschmid.net/TFC/img/TopOfSouthTowerBreaksOffAndExplodes.jpg

http://911review.com/coverup/fantasy/imgs/figure4.gif

Bazant and Mackey have no clue, and their papers are good for about one thing...not even the collapse initation follows the tipping pattern of Bazant's diagram.

wowsers scotty.

and we can expect your peer reviewed refutation of bazant when? In which journal?

I mean you have now hit on the perfect way to earn an PhD (to look at someone elses work and say they are full of **** and prove it.)

So prove it.

supply the engineerng, the load paths, and the physics.

I guarantee if you can do it, you will never have to worry about work again. Harvard, Columbia, Yale and all the other top schools will hire you immediately and tenure you.

When can we expect this paper?

[rwguinn]

I'm not so sure this is a supported statement. If memory serves, at one point the upper section tilts, begins to fall with very little angular momentum and then impacts the South? wall. At which point the upper section ceases to rotate and almost reverses direction (angular). Or at least appears to.

While there is no argument about the upper sections CG (or CM, we like to us CM, it's a physics thing ;) ) not having enough momentum to carry itself outside the footprint and topple, there is an issue with the CG of the upper section moving outside the "footprint" of the core.

This is no doubt debatable. I think there is sufficient obstruction by the debris to make a case either way. In my mind, based on the video evidence, I would lean towards the rotation of the upper section stopping at some point during the collapse.

Why? Because if the upper section did not stop rotating, it would have picked up angular momentum during the collapse. If it had, there is no case for the argument that the upper section remained intact. It would have simply pin wheeled out of control. Its own angular momentum responsible for its demise.

I hesitate to mention this for fear that somebody misconstrues it as evidence that the collapse didn't happen "naturally". Ultimately the collapse happened as a result of the damage incurred by the collision of planes carrying numerous lives, and not as a result of "thermite" or some of such nonsense.
See Mackey's reply above.
Yes, I agree, the impact forces likely stopped the rotation at some time, but I did say it was a simplification. The center of rotation would shift from the fulcrum edge to the CG (or CM), but the movement of the CG laterally would no longer have any force acting in that direction, and forces acting on the lower edge would attempt to right the structure, and thus move the CG back the way it came from. Vertically, there is no stopping it--the forces due to gravity are acting to pull it straight down.
With a CG at a conservative 30 meters (3/4 the way up), that puts the actual CG at the outside edge of the building (not outside the footprint) only after a 90 degree rotation, which did not occur.

[Furcifer]

The idea that the upper section would rotate while being connected by several core and perimeter columns is quite a fantasy, and totally contradicts the video and photo evidence.

After making this post I re-read your others and I don't have a clue what you are talking about. I now think you are trying to say the upper section couldn't have rotated without being totally severed from the lower section. As Ryan pointed out, the fulcrum would have been somewhere between the core and the exterior wall (Cases A and B in the white paper).

The Erich Hufscmid website you linked that image from says a lot about where you get your information from.

[Newtons Bit]

WTC1,2. The perimeter wall collapses. The top tilts towards the collapsing wall. This introduces torque to the remaining columns at the failed floor, a horizontal opposing force to the top and bottom of columns. One other perimeter wall has been largely severed by the plane, the remainder of the columns are either severed, bent, buckled, fire damaged and with increasing loading from progressively failing columns. The columns at or near the collapsing floor fail by horizontal shearing, not vertical buckling.

Due to the displaced tilt of the upper block, the columns above hit not the columns below, but the thin slabs below. As the slabs pancake to the ground, the perimeter and core columns topple.

http://911review.com/coverup/fantasy/imgs/figure4.gif
From Bazant - Fig. 4. Scenario of tilting of upper part of building ~South Tower - showing horizontal shear forces and displacement of upper and lower columns.

From Bazant’s first paper.
http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

Technically speaking (or jargonly speaking in any event), MOMENT is introduced into the columns. In structural terms, torque is a twisting force.

I would also add that it is impossible for a 14x14 column that is 12'4" long to fail in shear before compression-bending. In reality, all three loading types are additive. Even furthermore, the connections to the floor diaphragms and column splices will break long before the primary member has failed. This is shown by the structural steel remains: few of the columns are broken at any point other than at their splices. Even the ones that are severely mangled and damaged aren't sheared through.

[BasqueArch]

Technically speaking (or jargonly speaking in any event), MOMENT is introduced into the columns. In structural terms, torque is a twisting force.

Thank you for the moment-torque correction. Torque are moments, but what the columns at the failed floor were experiencing were moment forces not torque. Torque and moment are synonymous only in physics, not mechanical or structural engineering.

http://en.wikipedia.org/wiki/Torque

The progressive advance of science depends on one word having no more than one precise meaning, which is why I differentiate “hypothesis” and “theory”. Physics should use two terms differentiating torque and moment as does structural / mechanical engineering.

I would also add that it is impossible for a 14x14 column that is 12'4" long to fail in shear before compression-bending. In reality, all three loading types are additive. Even furthermore, the connections to the floor diaphragms and column splices will break long before the primary member has failed. This is shown by the structural steel remains: few of the columns are broken at any point other than at their splices. Even the ones that are severely mangled and damaged aren't sheared through.
ETA: The core and perimeter columns were 36 feet long at the splices

Bazant believes that at the base of the upper part of the South Tower the columns failed in shear in his first 2001 paper:

Appendix II. Why Didn’t the Upper Part Pivot About
Its Base? [See paper for supporting equations and Figure 3 illustration which I was not able to copy here]

…… Could the combined plastic shear resistance Fp of the columns
of one floor (Fig. 3 f) sustain this horizontal reaction? ….. The moment
equilibrium condition for the column as a free body shows that
each column can at most sustain the shear force ……[equations]
if the resisting columns were cold. Since they are hot, the horizontal
reaction to pivoting would exceed the shear capacity of the
heated floor still much more (and even more if fracture were
considered) . [equations]…… From this we further conclude
that the reaction at the base of the upper part of South
Tower must have begun shearing the columns plastically already
at the inclination [scientific notation] approx. 2.8 degrees.

The pivoting of the upper part must have started by an asymmetric
failure of the columns on one side of building, but already at
this very small angle the dynamic horizontal reaction at the base
of the upper part must have reduced the vertical load capacity of
the remaining columns of the critical floor (even if those were not
heated). That must have started the downward motion of the top
part of the South Tower, and afterwards its motion must have
become predominantly vertical (Fig. 4). Hence, a vertical impact
of the upper part onto the lower part must have been the dominant
mechanism.

See illustration in paper

Fig. 3. Pivoting of upper part of tower about its base, (a,b) with and without horizontal shear at base; (c ) Model for simplified analysis;
(d) Free-body diagram with inertia forces; (d,e) [sic](I believe Bazant meant (e,f)) Plastic horizontal shearing of columns in critical floor at base

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

[rwguinn]

Thank you for the moment-torque correction. Torque are moments, but what the columns at the failed floor were experiencing were moment forces not torque. Torque and moment are synonymous only in physics, not mechanical or structural engineering.

http://en.wikipedia.org/wiki/Torque

The progressive advance of science depends on one word having no more than one precise meaning, which is why I differentiate “hypothesis” and “theory”. Physics should use two terms differentiating torque and moment as does structural / mechanical engineering.


ETA: The core and perimeter columns were 36 feet long at the splices

Bazant believes that at the base of the upper part of the South Tower the columns failed in shear in his first 2001 paper:

snip for brevity.


http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

Engineers consider Torque to be a moment acting about the long axis of a member-beam, bolt, whatever.
36 foot long at the splices, but I believe NB was considering the distance between lateral supports?

[BenBurch]

I understood the question perfectly. The answer is that your assumptions are wrong. The upper section never stopped rotating.

As I explained in my whitepaper, however, which you obviously did not or cannot read, once the upper portion is loose, there is a restoring torque. This is because the tilt means that, as the upper block descends, it hits more of the lower floors on the down-tilted side. This should be obvious -- the down-tilted corner has fallen farther. If the block continues to rotate, this disparity will increase.

...

There is also an aerodynamic restoring force.

[rwguinn]

There is also an aerodynamic restoring force.
Other than compression by air "trapped" in the floors below, that force is so small as to be negligible--and even the compression vanishes against the overall force of the falling debris

[BasqueArch]

Engineers consider Torque to be a moment acting about the long axis of a member-beam, bolt, whatever.
36 foot long at the splices, but I believe NB was considering the distance between lateral supports?

Yes I’m sure that’s true. If Bazant is right and the columns failed in shear, not in buckling (at the critical floor only) lateral column supports should be less effective in resisting column shear.

The 36’ columns are more slender and more likely to fail at the body than at the weaker bolted or welded splices. The columns splices were also staggered 12 feet, making shear failure at the critical floor columns instead of at the splices more likely (each floor had 1/3 splices, 2/3 continuous columns.)

Both horizontal and vertical forces at the time the perimeter wall collapsed and top pivoted were enormous and I'm sure an equally persuasive case can be made that the critical floor columns failed in buckling like NB believes, not shear. Or both. I can't begin to understand the factors or do the bazantian math on this.

The collapse was chaotic and asymmetrical in many directions.
This is why Bazant wrote:

“For our purpose, we may assume that all the impact forces go into the columns and are distributed among them equally. Unlikely though such a distribution may be, it is nevertheless the most optimistic hypothesis to make because the resistance of the building to the impact is, for such a distribution, the highest. If the building is found to fail under a uniform distribution of the impact forces, it would fail under any other distribution.” - Bazant

And the math is also much easier.

[Grizzly Bear]

Engineers consider Torque to be a moment acting about the long axis of a member-beam, bolt, whatever.
36 foot long at the splices, but I believe NB was considering the distance between lateral supports?

Sounds that way to me.

[rwguinn]

Yes I’m sure that’s true. If Bazant is right and the columns failed in shear, not in buckling (at the critical floor only) lateral column supports should be less effective in resisting column shear.

The 36’ columns are more slender and more likely to fail at the body than at the weaker bolted or welded splices. The columns splices were also staggered 12 feet, making shear failure at the critical floor columns instead of at the splices more likely (each floor had 1/3 splices, 2/3 continuous columns.)

Both horizontal and vertical forces at the time the perimeter wall collapsed and top pivoted were enormous and I'm sure an equally persuasive case can be made that the critical floor columns failed in buckling like NB believes, not shear. Or both. I can't begin to understand the factors or do the bazantian math on this.

The collapse was chaotic and asymmetrical in many directions.
This is why Bazant wrote:

“For our purpose, we may assume that all the impact forces go into the columns and are distributed among them equally. Unlikely though such a distribution may be, it is nevertheless the most optimistic hypothesis to make because the resistance of the building to the impact is, for such a distribution, the highest. If the building is found to fail under a uniform distribution of the impact forces, it would fail under any other distribution.” - Bazant

And the math is also much easier.
I'm all for easier math--in fact My career has been a search for easier math. :D
Unfortunately, even the easiest is beyond the ken of the most intelligent of the truthers...

[Furcifer]

Unfortunately, even the easiest is beyond the ken of the most intelligent of the truthers...

Personally I've come to the conclusion that they are deliberately avoiding it.

I doubt either of us will be proven wrong anytime soon.

[Scott_Milner]

When someone can explain how the upper block rotates as shown in Bazant's diagram while connected to several perimeter and core columns, write a book on physics.

Please review the videos from multiple angles before submitting any white papers and claiming that an object begins to rotate in free space while joined by steel beams. The level of 'expertise' here is lacking I must say.

[Dave Rogers]

When someone can explain how the upper block rotates as shown in Bazant's diagram while connected to several perimeter and core columns, write a book on physics.

"Steel bends."

A book on physics, by Dave Rogers, Ph.D (Physics).

Chapter 1.

When steel structural members are subjected to sufficiently large forces, they bend.

The End.

[Scott_Milner]

That's right, steel bends. What provided the pivot point for the upper portion of the building to rotate in free space? Bazant's graphic shows the block rotating above the impact point. How is this possible? In reality as per video and photo evidence, the top section tilted at the impact floor - it did not rotate in mid air!

[twinstead]

That's right, steel bends. What provided the pivot point for the upper portion of the building to rotate in free space? Bazant's graphic shows the block rotating above the impact point. How is this possible? In reality as per video and photo evidence, the top section tilted at the impact floor - it did not rotate in mid air!

I don't know. I've heard not only those on this forum whom I think are pretty qualified disagree with you, but a crap-load of other pretty qualified people in my personal life who disagree with you. Frankly, you are just another truther on a relatively obscure internet forum complaining that the "official story" is impossible using personal incredulity.

Considering the large amount of evidence and consensus that contradicts you, you'll have to pardon me if I desire a second opinion. You'd think you would too.

[Dave Rogers]

That's right, steel bends. What provided the pivot point for the upper portion of the building to rotate in free space? Bazant's graphic shows the block rotating above the impact point. How is this possible?

Chapter Two.

One piece of steel can bend in more than one place.

Dave

[Scott_Milner]

Remind me to never buy your "book". The fact that it's bending in more than one place indicates that both the upper and lower sections are still attached and therefore a 'rotation' cannot occur. The upper block tilted. Tipped over at the point of impact. Bazant's image is pathetic. Not all core columns were cut.

[beachnut]

That's right, steel bends. What provided the pivot point for the upper portion of the building to rotate in free space? Bazant's graphic shows the block rotating above the impact point. How is this possible? In reality as per video and photo evidence, the top section tilted at the impact floor - it did not rotate in mid air!
How does something rotate about the center of mass? How is reality possible! Take some dynamics or some kind of engineering and stop displaying the delusional laws of conspiracy theorists.

Bazant work is a model; you show photos which prove Bazant's model was close. Your own post debunk your delusions about what should happen. Does your delusion have silent explosives or the nano-stupid-thermite?

[funk de fino]

Remind me to never buy your "book". The fact that it's bending in more than one place indicates that both the upper and lower sections are still attached and therefore a 'rotation' cannot occur. The upper block tilted. Tipped over at the point of impact. Bazant's image is pathetic. Not all core columns were cut.

Eventually the columns will break when bent. At the weakest point usually.

[Dave Rogers]

Remind me to never buy your "book". The fact that it's bending in more than one place indicates that both the upper and lower sections are still attached and therefore a 'rotation' cannot occur.

Imagine that some columns bend in two places. That allows a lateral displacement of the top of the column while it's still attached at both hinge points. Now imagine that some other columns bend in three places. That allows a lateral displacement of the top of the column, and a vertical displacement of the top of the column that's independent of the lateral displacement. That's all the degrees of freedom you need for a rotation to occur. The book you need to buy is a geometry primer.

The upper block tilted. Tipped over at the point of impact.

Can I suggest you check your facts very carefully on that one? The directions of rotation of the top blocks were not towards the point of impact, if I remember correctly, but towards the side that experienced the bowing between impact and collapse. You may be under a grave misconception as to the cause of collapse initiation.

Bazant's image is pathetic. Not all core columns were cut.

No core columns were "cut", they failed due to demand exceeding capacity. But it's fairly certain that they all failed, because none of them remained standing. We don't know the exact mechanism of that failure, but there's no reason why multiple hinge buckles should be inconsistent with what was observed. So what point, exactly, are you trying to make?

Dave

[BasqueArch]

.......
The 36’ columns are more slender and more likely to fail at the body than at the weaker bolted or welded splices. The columns splices were also staggered 12 feet, making shear failure at the critical floor columns instead of at the splices more likely (each floor had 1/3 splices, 2/3 continuous columns.)
...................

*cough*
Sorry for the interruption.

NIST mentions the perimeter columns were staggered. It does not mention that the core columns spliced connections were staggered. It mentions that the core columns were connected 3 feet above the slab at three story intervals.

http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201-2A%20Baseline.pdf

The construction photos show the three story core columns not staggered.

http://www.european911citizensjury.com/WTC%20-%20construction%20-%20good%20picture.jpg

Therefore the perimeter columns were staggered, the core columns were not.



-carry on.

[NutCracker]

When someone can explain how the upper block rotates as shown in Bazant's diagram while connected to several perimeter and core columns, write a book on physics.

Please review the videos from multiple angles before submitting any white papers and claiming that an object begins to rotate in free space while joined by steel beams. The level of 'expertise' here is lacking I must say.


I give in. Congratulations! The "official story" is now officially falsified! You are a genius. Did I say "genius?" Sorry to insult you. I meant to write "Genius." And even that is insufficient a wording to describe your out of this universe intellectual capabilities. Capabilities that make look Isaac Newton, Albert Einstein, Werner Heisenberg, Karl Friedrich Gauss etc. etc. combined look like retarded cockroaches. It's impssible that steel bends onder load! Congratulations! You have conclusively proven that 9/11 is an inside jobby job!

Now, since there is a limit to the amount and depth of stupidity I can bear, on ignore you go!

[TruthersLie]

That's right, steel bends. What provided the pivot point for the upper portion of the building to rotate in free space? Bazant's graphic shows the block rotating above the impact point. How is this possible? In reality as per video and photo evidence, the top section tilted at the impact floor - it did not rotate in mid air!

Ah.... it is the Bazant's model is wrong twoof.

Got it.

You know the model which was developed and published on 9/13...

I'm not surprised that it doesn't MATCH EXACTLY what was observed.

I'm also not surprised that you seem to have no understanding of what that model was intended to show.

Please explain to us how nanothermite can do what we all saw on 9/11.

I'm still waiting for your scientific papers which refute NIST. Where are they?

[BasqueArch]

When someone can explain how the upper block rotates as shown in Bazant's diagram while connected to several perimeter and core columns, write a book on physics.

Please review the videos from multiple angles before submitting any white papers and claiming that an object begins to rotate in free space while joined by steel beams. The level of 'expertise' here is lacking I must say.

Bazant's illustrations indicate an abbreviated pictorial version of physical events. The arrows indicate the direction and number of forces acting on a body, attached or detached. In Bazant's illustration the size of the arrows indicate the relative size of the acting forces. These” free body diagrams” are common in physics and structural engineering. You ignorance of this is evidence of your ignorance of physics and structural engineering. Therefore your ignorant opinions are worthless.

--------------------------------------------------------------------
You can't reason someone out of something they were not reasoned into.-Swift

[Newtons Bit]

Umm, guys. Bazant's "model" doesn't reflect reality. It's not supposed to. It's just a very fast and rough analysis of whether the towers would stand or not.

He shows that the columns would not have had the shear capacity to resist a rotation of the upper block. This is the last (strongest) limit state for those columns (and also the easiest one to calculate as it only requires a rough estimate of the total cross-section of steel and not it's shape or connections).

He also shows that the collapse once started (the upper block separated from the lower block) would continue, but he does so by again using the strongest limit state for collapse prevention: the columns striking axially on the columns below. We all know that the collapse didn't happen this way.

Again, the paper shows that the towers would continue to collapse even using assumptions most in favor of collapse prevention. It's not their to elaborate and diagrammatically explain what actually happened.

[archis]

What would happen if you removed the fulcrum point or it collapsed? Would the seesaw continue tipping or would it fall straight down due to gravity?

And what would happen if the falling fulcurum point would fall true something that has some bigger resistence then air?

Im skeptic about wtc1 and wtc2 fall. And i can't believe it could fall like this becouse of point like this:

1. - The plane and the fires damage the building. How many columns have been weakened/destroyed by this process in damaged floor/floors. I think they will be many undamaged columns.
2. - What is the possibility that all columns will loose their resistence simultaneily in damaged floor/floors by taking to account point 1. I dont belive that it could be simultanius.
3. - Ok construction fails at 1., 2. points. At what speed would floors collapse by taking to account bending columns/collapsing columns arent tin air. I dont believe it could be near free fall.
4. - What is the possibility that the floor construction part of the building wont take/soften impulse(take to account 3. point) of the crushing down upper part. Steel has some plastic properties too.
5. What is the possibility progresive collapse down will continue? Upper part gains mass by each collapsed floor, but also losses a lot of mass (in videos you see a lot of building parts trown out horizontally). Inn the same moment also the floor columns should have greater resistence properties as they are closer to the earth.

Personally i think the floor truss part of the building could pankake collapse, but the dense core part of the building should in worst case collapse like a broken tree rather then pankake collapse too.

[archis]

He shows that the columns would not have had the shear capacity to resist a rotation of the upper block.

Good, and what about diagonal members, wich are made to resist such forces in first place?

[funk de fino]

And what would happen if the falling fulcurum point would fall true something that has some bigger resistence then air?

Irrelevant.

Im skeptic about wtc1 and wtc2 fall. And i can't believe it could fall like this becouse of point like this:

1. - The plane and the fires damage the building. How many columns have been weakened/destroyed by this process in damaged floor/floors. I think they will be many undamaged columns.
2. - What is the possibility that all columns will loose their resistence simultaneily in damaged floor/floors by taking to account point 1. I dont belive that it could be simultanius.
3. - Ok construction fails at 1., 2. points. At what speed would floors collapse by taking to account bending columns/collapsing columns arent tin air. I dont believe it could be near free fall.
4. - What is the possibility that the floor construction part of the building wont take/soften impulse(take to account 3. point) of the crushing down upper part. Steel has some plastic properties too.
5. What is the possibility progresive collapse down will continue? Upper part gains mass by each collapsed floor, but also losses a lot of mass (in videos you see a lot of building parts trown out horizontally). Inn the same moment also the floor columns should have greater resistence properties as they are closer to the earth.

Personally i think the floor truss part of the building could pankake collapse, but the dense core part of the building should in worst case collapse like a broken tree rather then pankake collapse too.

WOW. The core remained standing afer the floors collapsed.

[funk de fino]

Good, and what about diagonal members, wich are made to resist such forces in first place?

There were none.

[Mancman]

I think they will be many undamaged columns.

I dont belive that it could be simultanius.

I dont believe it could be near free fall.



That's nice, but how about showing us something other than your uneducated, uninformed opinions?

[Carlos]

And what would happen if the falling fulcurum point would fall true something that has some bigger resistence then air?


Who said the resistence was equal or less than air resistence?

Im skeptic about wtc1 and wtc2 fall. And i can't believe it could fall like this becouse of point like this:

1. - The plane and the fires damage the building. How many columns have been weakened/destroyed by this process in damaged floor/floors. I think they will be many undamaged columns.



15% destroyed (for example) doesn't mean neither 15% more susceptible to collapse nor 15% less stable/resistant. There's a lot of nonlinearities and second order effects.

2. - What is the possibility that all columns will loose their resistence simultaneily in damaged floor/floors by taking to account point 1. I dont belive that it could be simultanius.


Who said it was simultaneily? Do you know what is supposed to happen when columns fail?

[archis]

There were none.
Such high structure with no elements who could take horizonatal forces like wind? Well i heard something the perimter column design were good at it, but the cores should have them. And i see them here
www(dot)european911citizensjury.c...%20picture.jpg
By the why does anybody have some source where can you find structural drawins of wtc1 or 2?

[Grizzly Bear]

Umm, guys. Bazant's "model" doesn't reflect reality. It's not supposed to. It's just a very fast and rough analysis of whether the towers would stand or not.
I think the problem with most conspiracy nuts going after his paper is that they interpret it as a model reflecting reality, not as a demonstrative model. I've seen this with TS, Heiwa and countless other figures. Even when you tell them it's was a demonstration model assuming an optimistic set of conditions they can't read it that way.

[ElMondoHummus]

I think the problem with most conspiracy nuts going after his paper is that they interpret it as a model reflecting reality, not as a demonstrative model. I've seen this with TS, Heiwa and countless other figures. Even when you tell them it's was a demonstration model assuming an optimistic set of conditions they can't read it that way.

Well, rather, I'd say it's because they're so invested in their argument that they must avoid accepting that it's a limiting case.

[Seymour Butz]

That's right, steel bends. What provided the pivot point for the upper portion of the building to rotate in free space? Bazant's graphic shows the block rotating above the impact point. How is this possible? In reality as per video and photo evidence, the top section tilted at the impact floor - it did not rotate in mid air!

It didn't just rotate to the left, in the 9 o'clock direction.

It's clearly seen to also go down, in the 6 o'clock direction.

Net is about the 6:30 direction.

The pivot point was the far side ext columns, but only for a moment, when they also gave up supporting the building.

[Carlos]

3. - Ok construction fails at 1., 2. points. At what speed would floors collapse by taking to account bending columns/collapsing columns arent tin air. I dont believe it could be near free fall.


Have you heard about "verinage demolition"?
http://www.youtube.com/watch?v=NwFHEoiUZ7o

4. - What is the possibility that the floor construction part of the building wont take/soften impulse(take to account 3. point) of the crushing down upper part. Steel has some plastic properties too.


Steel plastic property means to deform without stress increase.

5. What is the possibility progresive collapse down will continue? Upper part gains mass by each collapsed floor, but also losses a lot of mass (in videos you see a lot of building parts trown out horizontally).


How much mass each collapsed floor gained and how much they lose?

Inn the same moment also the floor columns should have greater resistence properties as they are closer to the earth.


What about the increase of the mass and velocity?

Personally i think the floor truss part of the building could pankake collapse, but the dense core part of the building should in worst case collapse like a broken tree rather then pankake collapse too.


No man, buildings and trees have structures totaly different.

[Newtons Bit]

Good, and what about diagonal members, wich are made to resist such forces in first place?

Welcome to the forums.

The only braced frames in the WTC were at the mechanical floors and at floor 7 and below. The lateral force resisting system was the perimeter moment frames. Spaced at 3'-4" o.c. and with very deep spandrel plates in between them, they are capable of resisting the high design wind loads. They were so stiff that many likened them to a steel wall with penetrations. This, however, is really nothing more than a helper to help explain the system to the non-engineer community.

The core was not capable of resisting lateral forces (except at the lower levels where it was "trussed up").

[archis]

Have you heard about "verinage demolition"?
Steel plastic property means to deform without stress increase.
How much mass each collapsed floor gained and how much they lose?
What about the increase of the mass and velocity?
No man, buildings and trees have structures totaly different.

I have heard about veringae and it has change some of my opinions. But verinage is for structures with parallel bearing walls and I find videos of precast RC panel structures only(no steel). +the constr. is weakened.

Steel plastic property means for me that element is able to deform ( no crush like fragile vase). deform with out big stress it is plastic stage named yalding(or so).

Mass, velocity increase question leads to that point is the down structure albe to stop crushing or not. I dont know sure answer for this, but many youtube videos show that it is possible to stop, but havnt see any other videos of steel progresive colllapse excluding wtc's.

[Carlos]

Steel plastic property means for me that element is able to deform ( no crush like fragile vase).

You made a confusion, this property is called ductility.

[A W Smith]

*cough*
Sorry for the interruption.

NIST mentions the perimeter columns were staggered. It does not mention that the core columns spliced connections were staggered. It mentions that the core columns were connected 3 feet above the slab at three story intervals.

http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201-2A%20Baseline.pdf

The construction photos show the three story core columns not staggered.

http://www.european911citizensjury.com/WTC%20-%20construction%20-%20good%20picture.jpg

Therefore the perimeter columns were staggered, the core columns were not.



-carry on.

here's a better picture

http://wtc7lies.googlepages.com/9999004225-l.jpg/9999004225-l-full.jpg

[TruthersLie]

I have heard about veringae and it has change some of my opinions. But verinage is for structures with parallel bearing walls and I find videos of precast RC panel structures only(no steel). +the constr. is weakened.


This is inaccurate. In the pattent for the technique they state that they do NOT weaken the construction besides for the ONE floor where they knock off the support. They do NOT preweaken ANY of the other part of the structure.

[Dave Rogers]

And what would happen if the falling fulcurum point would fall true something that has some bigger resistence then air?

If I understand your question correctly, then the answer is that the rate of acceleration would be significantly less than 1G, as was the case for the entire collapses of both WTC1 and WTC2 and the majority of the collapse of WTC7.

1. - The plane and the fires damage the building. How many columns have been weakened/destroyed by this process in damaged floor/floors. I think they will be many undamaged columns.

NIST modelled the damage caused by the planes' impacts. Their results were independently verified by Purdue University. The number of damaged and broken core columns after the plane impacts cannot be known with certainty, but a good estimate can be, and has been, made. The number of severed perimeter columns is of course known from photographs.

2. - What is the possibility that all columns will loose their resistence simultaneily in damaged floor/floors by taking to account point 1. I dont belive that it could be simultanius.

Nor does anyone else. In fact, had it been simultaneous, there would have been no rotation of the upper blocks. Since WTC1 and WTC2 both exhibited rotation of the upper block, in neither case was the failure of all columns simultaneous. Incidentally, we know from the collapse of WTC7 that there was about 4-8 seconds delay between the failure of the first core columns and of the perimeter columns; again, not simultaneous.

The failures would, however, have progressed laterally across the structure as the loads redistributed. This would have happened rather quickly, as it would be limited by the rate of progression of an elastic wave in steel.

3. - Ok construction fails at 1., 2. points. At what speed would floors collapse by taking to account bending columns/collapsing columns arent tin air. I dont believe it could be near free fall.

Belief isn't the only tool in the box. We have the ability to analyse the situation and make estimates and calculations. When we do this, we find that the collapse times of all three towers are predicted to well within the errors of observation.

4. - What is the possibility that the floor construction part of the building wont take/soften impulse(take to account 3. point) of the crushing down upper part. Steel has some plastic properties too.

Zero, by a long way. The floors weren't strong enough to take the static weight of the upper blocks, even neglecting load amplification.

5. What is the possibility progresive collapse down will continue? Upper part gains mass by each collapsed floor, but also losses a lot of mass (in videos you see a lot of building parts trown out horizontally). Inn the same moment also the floor columns should have greater resistence properties as they are closer to the earth.

Again, this has all been worked out. But if you simply think about it for a moment, it's quite clear. The supports increase in strength linearly as you go down the building. The potential energy available for destroying supports increases linearly for each unit mass, but mass is added as well. If the first set of supports fails, then the collapse will go all the way to the ground unless the mass loss is very nearly as fast as the collapse accumulates it. There was simply no possible way for that much mass to be lost.

Personally i think the floor truss part of the building could pankake collapse, but the dense core part of the building should in worst case collapse like a broken tree rather then pankake collapse too.

You're entitled to your opinion, of course, but I don't think you'll find any structural engineers who agree with you. The core structure alone was never designed to support its own weight without the lateral bracing to the perimeter columns provided by the floor trusses. Once the floor trusses were gone, the core wasn't rigid enough to stay standing. And, of course, the cross members of the core must have been hit by falling debris as well, so you're then left with the individual columns, which were even less able to withstand the buckling forces from their own weights.

And finally, of course, there's the complete absence of any other rational explanation of the collapse propagation. Precisely timed explosives? Doesn't pass the giggle test; the exposions would have to have been timed to the millisecond level. Thermite? Doesn't even pass the hysterical laughter test, for the same reason; you can't time thermite to the nearest second, even if it could cut vertical steel members. Nanothermite? Same problem - the timing is limited by thermal conduction, not by ignition rate.

All in all, the evidence is uniformly in favour of progressive collapse due to gravity, initiated by impact damage and thermal effects. Beliefs that don't account for this evidence are best re-examined.

Dave

[TruthersLie]

And what would happen if the falling fulcurum point would fall true something that has some bigger resistence then air?

Im skeptic about wtc1 and wtc2 fall. And i can't believe it could fall like this becouse of point like this:


Lets see if we have some new claims. I doubt it.


1. - The plane and the fires damage the building. How many columns have been weakened/destroyed by this process in damaged floor/floors. I think they will be many undamaged columns.


Why don't you look it up? Nist and Fema have done a few reports on this... you can find it rather easily.


2. - What is the possibility that all columns will loose their resistence simultaneily in damaged floor/floors by taking to account point 1. I dont belive that it could be simultanius.

Possibility? OH you want probabilities? tsk tsk tsk.

And you use a word you don't seem to understand. Simultaneously. They didn't fail simultaenously. There was a collapsed in a series as the load paths were overhwhelmed and then they too failed. They failed FAST but they were NOT simultaneous.


3. - Ok construction fails at 1., 2. points. At what speed would floors collapse by taking to account bending columns/collapsing columns arent tin air. I dont believe it could be near free fall.

Truther LIE. NONE of them fell "near freefall." The towers collapses were 15 seconds for one, over 20 seconds for another, and about 18 seconds for wtc7

None of those are "near freefall."


4. - What is the possibility that the floor construction part of the building wont take/soften impulse(take to account 3. point) of the crushing down upper part. Steel has some plastic properties too.


this has been explained many times. Maybe you should look up Bazant...


5. What is the possibility progresive collapse down will continue? Upper part gains mass by each collapsed floor, but also losses a lot of mass (in videos you see a lot of building parts trown out horizontally). Inn the same moment also the floor columns should have greater resistence properties as they are closer to the earth.


This has been shown and proven that once the collapse started it was not going to finish.

Please find just one peer reviewed engineering journal article which agrees with the point you ar trying to make. Just one. In any language.


Personally i think the floor truss part of the building could pankake collapse, but the dense core part of the building should in worst case collapse like a broken tree rather then pankake collapse too.

The core remained standing for 20 to 30 seconds after the collapse, then it collapsed under the strain.

[R.Mackey]

Such high structure with no elements who could take horizonatal forces like wind? Well i heard something the perimter column design were good at it, but the cores should have them. And i see them here
www(dot)european911citizensjury.c...%20picture.jpg
By the why does anybody have some source where can you find structural drawins of wtc1 or 2?

Ah geez, not this crap again.

There were diagonal elements in the core in only a few places -- below Floor 8, on the mechanical and skylobby floors, and in the hat truss. Over 90% of the core had no diagonal bracing at all. This is described and modeled in NCSTAR1-1 and 1-2A respectively.

Simple fact. Deal with it.

[Hokulele]

Welcome to the forums.

The only braced frames in the WTC were at the mechanical floors and at floor 7 and below. The lateral force resisting system was the perimeter moment frames. Spaced at 3'-4" o.c. and with very deep spandrel plates in between them, they are capable of resisting the high design wind loads. They were so stiff that many likened them to a steel wall with penetrations. This, however, is really nothing more than a helper to help explain the system to the non-engineer community.

The core was not capable of resisting lateral forces (except at the lower levels where it was "trussed up").


I know the hat truss helped redistribute the loads between the perimeter columns and the core columns. I believe they also helped with the lateral forces. Is this true? IANASE.

[Newtons Bit]

I know the hat truss helped redistribute the loads between the perimeter columns and the core columns. I believe they also helped with the lateral forces. Is this true? IANASE.

Here's an analogy (a pretty bad one as I'll explain later):

Imagine a tall slender cardboard box. It is open at the top. Imagine how the 4 walls deflect when pushed against. Now imagine that the top is sealed tight. Any force acting against the top of the box is spread out amongst all the walls. This is sort of what the hat truss does.

The analogy falls apart once you realize that every single concrete floor in the building braces the perimeter walls and distributed lateral forces. The hat truss just does that job much better than the concrete floors.

[Hokulele]

Thanks, that is pretty much how I was picturing it.

[funk de fino]

Such high structure with no elements who could take horizonatal forces like wind? Well i heard something the perimter column design were good at it, but the cores should have them. And i see them here
www(dot)european911citizensjury.c...%20picture.jpg
By the why does anybody have some source where can you find structural drawins of wtc1 or 2?

Sorry, that picture shows the crane support columns. If you look closer you can see the cranes on the columns you are talking about.

I see you are probably French. The external columns and the core columns were connected by the floors and they worked together to carry gravity and lateral loads. The core mostly gravity IIRC.

[DGM]

Sorry, that picture shows the crane support columns. If you look closer you can see the cranes on the columns you are talking about.

I see you are probably French. The external columns and the core columns were connected by the floors and they worked together to carry gravity and lateral loads. The core mostly gravity IIRC.
I had a feeling that's what he was posting (I didn't look at the picture). I actually had Chris7 apologize and retract a statement (shock) over those tower crane supports when I called him on it.

[tsig]

I give in. Congratulations! The "official story" is now officially falsified! You are a genius. Did I say "genius?" Sorry to insult you. I meant to write "Genius." And even that is insufficient a wording to describe your out of this universe intellectual capabilities. Capabilities that make look Isaac Newton, Albert Einstein, Werner Heisenberg, Karl Friedrich Gauss etc. etc. combined look like retarded cockroaches. It's impssible that steel bends onder load! Congratulations! You have conclusively proven that 9/11 is an inside jobby job!

Now, since there is a limit to the amount and depth of stupidity I can bear, on ignore you go!

He's a Genius on the order of W. E. Coyote

[Reactor drone]

I had a feeling that's what he was posting (I didn't look at the picture). I actually had Chris7 apologize and retract a statement (shock) over those tower crane supports when I called him on it.

http://www.european911citizensjury.com/WTC%20-%20construction%20framework-a-lighter-b.jpg

Heres the pic if you want to look,shows the crane towers in the core during construction.

ETA It does also show some of the cross bracing that was in the sub floor and lower levels.

[archis]

This is inaccurate. In the pattent for the technique they state that they do NOT weaken the construction besides for the ONE floor where they knock off the support. They do NOT preweaken ANY of the other part of the structure.

In patent also has a quote that you can destroy any kind, height of structures. Wish you luck to destroy pyramids or ditch near a road. Patents are made by people like lawyers. Things you patent dont have to work or even to be real. So its a really bad source to learn something.

I see cleary in videos and pictures they are wekaned (www(dot)cg94.fr/node/11190). And i am not sure about the parts wich i dont see. Stiffnes walls are removed to make floors collapse like cards.

If you consider that veringae RC demulation prooves that wtc1 and wtc2 can collapse like this then why do you laugh out this video here that 2 guys destroy wtc1 and wtc2 makets of snow? Both debating sides should agree on one construction.

[archis]

Sorry, that picture shows the crane support columns. If you look closer you can see the cranes on the columns you are talking about.

I see you are probably French. The external columns and the core columns were connected by the floors and they worked together to carry gravity and lateral loads. The core mostly gravity IIRC.

Im latvian, sorry for my bad english. Im to lazy to chek my spelling, altough i have problems with it in my own mother language.

Maybe it is the key factor that the core was not braced well enough. A doubt made.

[archis]

Lets see if we have some new claims. I doubt it.
Why don't you look it up? Nist and Fema have done a few reports on this... you can find it rather easily.
Possibility? OH you want probabilities? tsk tsk tsk.
And you use a word you don't seem to understand. Simultaneously. They didn't fail simultaenously. There was a collapsed in a series as the load paths were overhwhelmed and then they too failed. They failed FAST but they were NOT simultaneous.
Truther LIE. NONE of them fell "near freefall." The towers collapses were 15 seconds for one, over 20 seconds for another, and about 18 seconds for wtc7
None of those are "near freefall."
this has been explained many times. Maybe you should look up Bazant...
This has been shown and proven that once the collapse started it was not going to finish.
Please find just one peer reviewed engineering journal article which agrees with the point you ar trying to make. Just one. In any language.
The core remained standing for 20 to 30 seconds after the collapse, then it collapsed under the strain.

Thats my interpretation. We have a big black box. You, scientists also give interpretations of what is inside the black box. Maybe their claims, calculations arent far from truth, but my doubts and curiosity will be destroyed only by a real test. Thats the point you can convince me for sure. Until now steel hasnt collapsed like this and thats point for me. Our world is so difficult.

[TruthersLie]

In patent also has a quote that you can destroy any kind, height of structures. Wish you luck to destroy pyramids or ditch near a road. Patents are made by people like lawyers. Things you patent dont have to work or even to be real. So its a really bad source to learn something.


If they are not following the patent then they are putting people in danger. Their own documents state they do NOT preweaken the lower sections and by looking at the video you can clearly see the lower sections have NOT been preweakened.


I see cleary in videos and pictures they are wekaned (www(dot)cg94.fr/node/11190). And i am not sure about the parts wich i dont see. Stiffnes walls are removed to make floors collapse like cards.


Only in the area where the hydraulic jacks are located. None of the lower floors have been modified.


If you consider that veringae RC demulation prooves that wtc1 and wtc2 can collapse like this then why do you laugh out this video here that 2 guys destroy wtc1 and wtc2 makets of snow? Both debating sides should agree on one construction.

because one is structurally possible, and a tower PACKED with snow is entirely different han an office building that is 95% AIR.

[archis]

because one is structurally possible, and a tower PACKED with snow is entirely different han an office building that is 95% AIR.

Funny answer. I think A proves B. Im right and truth is on my side. your C doesnt disprove B, becouse i think so. <- thats why I think all arguing sides should agree on one test (I will repeat my self).

verinage. If they don't weaken lower, uppr floors (have no sure source for this and wonder why are you so sure) in precast RC panel structures then i agree that it can pankake collapse when few floors in the midle vanish/are simultanualy destroyed.

[archis]

The core structure alone was never designed to support its own weight without the lateral bracing to the perimeter columns provided by the floor trusses.
Dave

Many have made here good points like this about the core. Do you know where to get structural drawings of wtc for this, to be sure and for interest. As I understand the lateral support do give also floor beams wich should connect core columns to each other.

Also have questions about terms. Lateral support is a support point in direction x wich defines the calculating hight of column in direction x?

[triforcharity]

In patent also has a quote that you can destroy any kind, height of structures. Wish you luck to destroy pyramids or ditch near a road. Patents are made by people like lawyers. Things you patent dont have to work or even to be real. So its a really bad source to learn something.

I see cleary in videos and pictures they are wekaned (www(dot)cg94.fr/node/11190). And i am not sure about the parts wich i dont see. Stiffnes walls are removed to make floors collapse like cards.

If you consider that veringae RC demulation prooves that wtc1 and wtc2 can collapse like this then why do you laugh out this video here that 2 guys destroy wtc1 and wtc2 makets of snow? Both debating sides should agree on one construction.

We laughed at them because snow, lemons, pizza boxes, and office paper trays have all been used to simulate the WTC. Well, as I am sure you will agree, those do NOT represent the WTC very well, as none of those objects behave anything like the WTC would.

[triforcharity]

Thats my interpretation. We have a big black box. You, scientists also give interpretations of what is inside the black box. Maybe their claims, calculations arent far from truth, but my doubts and curiosity will be destroyed only by a real test. Thats the point you can convince me for sure. Until now steel hasnt collapsed like this and thats point for me. Our world is so difficult.


Untill now, no steel framed skyscraper had 767's flown into them at ~500 MPH, causing major structural damage, having huge, acre sized fires instantly over ~5 floors, followed by NO FIREFIGHTING.

Its very simple really. Other steel framed structures have collapsed from fire over the years.

Kader Toy Factory

Sight and Sound Ampitheature in PA

These are just two. There are many more.

[Furcifer]

Do you know where to get structural drawings of wtc for this, to be sure and for interest. As I understand the lateral support do give also floor beams wich should connect core columns to each other.


A group of scientists compiled all the relevant information into a report. Plus, they did computer simulations.

[BasqueArch]

Until now steel hasnt collapsed like this and thats point for me. Our world is so difficult.

911Research Bestows Temporary Circular Logic Pass to BasqueArch

“Excepting the three 9-11 collapses, no fire, however severe, has ever caused a steel-framed high-rise building to collapse.” Therefore the three 9-11 collapses must have been Controlled Demolitioned.

http://911research.wtc7.net/wtc/analysis/compare/fires.html

Not true. ALL steel-framed high-rise buildings hit by >120 ton airplanes traveling > 400 mph and ignited by their debris have always collapsed . Therefore the three 9-11 collapses must have done so by gravity only.

Thats my interpretation. We have a big black box. You, scientists also give interpretations of what is inside the black box. Maybe their claims, calculations arent far from truth, but my doubts and curiosity will be destroyed only by a real test. Thats the point you can convince me for sure. … Our world is so difficult.

Here’s an easy visual evidence only explanation that doesn’t rely on scientific interpretations or tests:

http://forums.randi.org/showthread.php?postid=5005477#post5005477

[Tony Szamboti]

The floors weren't strong enough to take the static weight of the upper blocks, even neglecting load amplification.

The floors outside the core could take a 29 million lb. vertical static load before failure and for the beams inside the core I would estimate an additional 15 million lbs. giving a total of 44 million lbs. per floor. The upper block of WTC 1 weighed approximately 68 million lbs., so even if all the connected columns magically missed each other after buckling, the first collision should have caused a much more significant resistance to acceleration than what is observed.


The core structure alone was never designed to support its own weight without the lateral bracing to the perimeter columns provided by the floor trusses. Once the floor trusses were gone, the core wasn't rigid enough to stay standing.

Where is your evidence for this? The perimeter columns needed lateral support from the floor system outside the core but it is unlikely that the three dimensional core required it. The core beam to column connections have not been made publicly available, so I don't know what basis you are using for your contention here.

[rwguinn]

The floors outside the core could take a 29 million lb. vertical static load before failure and for the beams inside the core I would estimate an additional 15 million lbs. giving a total of 44 million lbs. per floor. The upper block of WTC 1 weighed approximately 68 million lbs., so even if all the connected columns magically missed each other after buckling, the first collision should have caused a much more significant resistance to acceleration than what is observed.
That 29,000,000 lb is 725 lb/ft2
so you are now running a SF=5 for the floors (150 psf design load). We disproved your SF of 3, so now you up it?



Where is your evidence for this? The perimeter columns needed lateral support from the floor system outside the core but it is unlikely that the three dimensional core required it. The core beam to column connections have not been made publicly available, so I don't know what basis you are using for your contention here.we could (and have) ask you the same thing/
Show us evidence, not numbers flying out of your butt.

[Carlos]

The floors outside the core could take a 29 million lb. vertical static load before failure and for the beams inside the core I would estimate an additional 15 million lbs. giving a total of 44 million lbs. per floor. The upper block of WTC 1 weighed approximately 68 million lbs., so even if all the connected columns magically missed each other after buckling, the first collision should have caused a much more significant resistance to acceleration than what is observed.


Where is your evidence for the bold part?

[Tony Szamboti]

That 29,000,000 lb is 725 lb/ft2
so you are now running a SF=5 for the floors (150 psf design load). We disproved your SF of 3, so now you up it?


we could (and have) ask you the same thing/
Show us evidence, not numbers flying out of your butt.

You haven't disproved anything concerning the factor of safety of the core columns.

As for the 29 million lbs. static load capacity for the floors outside of the core you will have to take that up with the NIST as that is the value they come up with also.

The floors outside of the core had a huge factor of safety. Read the NIST FAQ from December 2007.

[Tony Szamboti]

Where is your evidence for the bold part?

The resistance observed was about 30 to 35% of gravity so if you can do the simple math for just the floor resistance you will see there is a problem.

[twinstead]

What exactly does "the resistance observed" mean?

[Grizzly Bear]

That 29,000,000 lb is 725 lb/ft2
so you are now running a SF=5 for the floors (150 psf design load). We disproved your SF of 3, so now you up it?
From what I can tell... he's ignoring the impact loading from the upper section falling on the floors again. :\
This is much higher than the static load of the structure.

[jhunter1163]

:confused:

How can resistance be measured as a percentage of gravity?

What I think Tony is trying to say here is that the resistance of the building slowed the collapse by 30-35%. His argument is that collapse should have been slowed by more than that, if not prevented.

Do I have that right?

I know he's wrong, I just want to make sure that I'm not misunderstanding his argument.

[Tony Szamboti]

From what I can tell... he's ignoring the impact loading from the upper section falling on the floors again. :\
This is much higher than the static load of the structure.

No, I am not ignoring it. Amplified loading requires deceleration and there was none, which is what you seem to be forgetting.

[Grizzly Bear]

No, I am not ignoring it. Amplified loading requires deceleration and there was none, which is what you seem to be forgetting.

The news may surprise you but the most people don't take literal, the model assuming a completely perfect column to column impact at collapse initiation.

Furthermore, the net acceleration being less than 9.81 m/s/s and your acknowledgment of it indicates that you'd in fact like to have your cake and eat it too...

[Tony Szamboti]

The news may surprise you but the most people don't take literal, the model assuming a completely perfect column to column impact at collapse initiation.

Furthermore, the net acceleration being less than 9.81 m/s/s and your acknowledgment of it indicates that you'd in fact like to have your cake and eat it too...

Can you estimate what the acceleration rate should have been with some basis for it?

[Furcifer]

Can you estimate what the acceleration rate should have been with some basis for it?

0.8935G, cuz I said so.

[rwguinn]

No, I am not ignoring it. Amplified loading requires deceleration and there was none, which is what you seem to be forgetting.
(:dl: :dl: :dl: )*1/0

[Tony Szamboti]

The laughing dogs do seem appropriate for you rwguinn as you tend to be all bark and no bite. In this case, it would be all laugh and no bite.

So here is to you :dl: and not letting the need for facts get in your way.

[Grizzly Bear]

Can you estimate what the acceleration rate should have been with some basis for it?
Why? I don't have any problem with the observed collapse times.
It took 15 seconds for the main collapse to completely propagate, and equates to an average of 50% longer than would have taken assuming freefall acceleration.


The laughing dogs do seem appropriate for you rwguinn as you tend to be all bark and no bite. In this case, it would be all laugh and no bite.

So here is to you :dl: and not letting the need for facts get in your way.

In this context ignoring and denying the dynamic loads are one and the same, and worthy of a hefty laugh :dl:

It comes as no surprise to me since you also deny that the columns in the fire regions buckled, or that the towers listed as the collapse commenced in both towers. I've shown you both. If you choose to ignore it that ain't my problem!

[triforcharity]

The floors outside the core could take a 29 million lb. vertical static load before failure and for the beams inside the core I would estimate an additional 15 million lbs. giving a total of 44 million lbs. per floor. The upper block of WTC 1 weighed approximately 68 million lbs., so even if all the connected columns magically missed each other after buckling, the first collision should have caused a much more significant resistance to acceleration than what is observed.




Where is your evidence for this? The perimeter columns needed lateral support from the floor system outside the core but it is unlikely that the three dimensional core required it. The core beam to column connections have not been made publicly available, so I don't know what basis you are using for your contention here.

Can we get some evidence of this calculation?? I notice you say STATIC load, why did not not caalculate the DYNAMIC load for just one section of floor?? 44 million pounds per floor, over the entire area?? Or is that per section??

It seems to me that you might be a little off in your calculations. Either that, or you are being dishonest intentially. Which is it Tony??

[Tony Szamboti]

Can we get some evidence of this calculation?? I notice you say STATIC load, why did not not caalculate the DYNAMIC load for just one section of floor?? 44 million pounds per floor, over the entire area?? Or is that per section??

It seems to me that you might be a little off in your calculations. Either that, or you are being dishonest intentially. Which is it Tony??

I told you earlier that the NIST calculated a 29 million lb. static load capacity for the floor system outside of the core on each story. My own calculations produced a similar value.

I then explained that I estimate the horizontal beams in the core to have a vertical load capacity of about 15 million lbs. at the 98th floor level where the collapse initiated in WTC 1. The beams and their column connections will get heavier lower in the building.

Adding the two gives a total vertical load capacity of approximately 44 million lbs. for the full floor at the 98th story and would be greater lower in the building with the core beams having a greater capacity.

On what basis can you make the comment that I might be off in the calculations?

[Carlos]

Tony Szamboti

Have you already heard about "verinage demolition"?

[Grizzly Bear]

Can we get some evidence of this calculation?? I notice you say STATIC load, why did not not caalculate the DYNAMIC load for just one section of floor?? 44 million pounds per floor, over the entire area?? Or is that per section??

It seems to me that you might be a little off in your calculations. Either that, or you are being dishonest intentially. Which is it Tony??

the 29,000,000 pound figure is correct. The problem for tony is accepting that the dynamic load -- rather that one existed contrary to what he's asserting -- & -- accepting that the collapse was "smeared" across several floors due to the upper block's rotation -- means accepting that this load capacity was breached. Don't expect it to happen any time soon.

[rwguinn]

The floors outside the core could take a 29 million lb. vertical static load before failure....

...
As for the 29 million lbs. static load capacity for the floors outside of the core you will have to take that up with the NIST as that is the value they come up with also.

The floors outside of the core had a huge factor of safety. Read the NIST FAQ from December 2007.

I told you earlier that the NIST calculated a 29 million lb. static load capacity for the floor system outside of the core on each story. My own calculations produced a similar value.

....

On what basis can you make the comment that I might be off in the calculations?

Move goal posts around much, Tony.
You can't even keep your OWN story straight.

You are certainly not ignorant. THAT condition is curable. So we have to go with some other condition which LOOKS like ignorance, but which is not curable....

[Tony Szamboti]

Move goal posts around much, Tony.
You can't even keep your OWN story straight.

You are certainly not ignorant. THAT condition is curable. So we have to go with some other condition which LOOKS like ignorance, but which is not curable....

You obviously like being obtuse while trying to ridicule others and if what we are discussing here wasn't such a serious issue I would actually laugh at some of the things you say.

If you ever decide to actually debate the facts let me know.

[triforcharity]

I told you earlier that the NIST calculated a 29 million lb. static load capacity for the floor system outside of the core on each story. My own calculations produced a similar value.

I then explained that I estimate the horizontal beams in the core to have a vertical load capacity of about 15 million lbs. at the 98th floor level where the collapse initiated in WTC 1. The beams and their column connections will get heavier lower in the building.

Adding the two gives a total vertical load capacity of approximately 44 million lbs. for the full floor at the 98th story and would be greater lower in the building with the core beams having a greater capacity.

On what basis can you make the comment that I might be off in the calculations?

Maybe because you arae using a static load calculation for the entire floor, instead of a dynamic load. Plus, its a moost point. The possibility of the upper section hitting the next lowest floor, evenly distributing its weight is, IMHO, quite assinine.

[Tony Szamboti]

Tony Szamboti

Have you already heard about "verinage demolition"?

Yes.

[Tony Szamboti]

Maybe because you arae using a static load calculation for the entire floor, instead of a dynamic load. Plus, its a moost point. The possibility of the upper section hitting the next lowest floor, evenly distributing its weight is, IMHO, quite assinine.

Do you have any basis for what you are saying or is it just what you feel?

[R.Mackey]

Anybody needs any help with Tony, just let me know. Looks like old, tired, debunked crap, however.

[Carlos]

Yes.

So, what can you say about the resistant of the floors during the colapse? Why the buildings colapse at near free-fall speed?

http://www.youtube.com/watch?v=NwFHEoiUZ7o

[Tony Szamboti]

Anybody needs any help with Tony, just let me know. Looks like old, tired, debunked crap, however.

They apparently need help as they aren't providing an estimate of what the acceleration should have been with some sort of basis.

What is your estimate Ryan? You also know better than to presume that every column missed or that the connected buckled columns did not cause interference.

[R.Mackey]

What's "my estimate?" The video shows an average of about 0.3 g resistance from the lower portion. This is quite easily reconciled with the expected strength, momentum transfer, and the smearing effect since not all of that mass hit the floors at once, since the floors aren't in blueprint condition, and taking elasticity into account.

As you already know. You've been taken to task on this very issue in at least three threads that I can think of.

Get a new act. This one is old.

[Tony Szamboti]

So, what can you say about the resistant of the floors during the colapse? Why the buildings colapse at near free-fall speed?

http://www.youtube.com/watch?v=NwFHEoiUZ7o

The velocity of the upper blocks in each of these Verinage demolitions has been measured and there is a definitive deceleration and velocity loss when the upper block impacts the lower block. The deceleration causes an amplified load and that is the only way to overcome the reserve strength of the structure below and continue the collapse naturally after using external energy devices to remove several stories.

In the case of WTC 1 there is no deceleration and velocity loss. The upper block just accelerates at 65 to 70% of the rate of gravity throughout the entire nine stories it could be measured. So where does the overload come from?

[twinstead]

The velocity of the upper blocks in each of these Verinage demolitions has been measured and there is a definitive deceleration and velocity loss when the upper block impacts the lower block. The deceleration causes an amplified load and that is the only way to overcome the reserve strength of the structure below and continue the collapse naturally after using external energy devices to remove several stories.

In the case of WTC 1 there is no deceleration and velocity loss. The upper block just accelerates at 65 to 70% of the rate of gravity throughout the entire nine stories it could be measured. So where does the overload come from?

Even I know this is total BS, and that's sad.

[Tony Szamboti]

What's "my estimate?" The video shows an average of about 0.3 g resistance from the lower portion. This is quite easily reconciled with the expected strength, momentum transfer, and the smearing effect since not all of that mass hit the floors at once, since the floors aren't in blueprint condition, and taking elasticity into account.

As you already know. You've been taken to task on this very issue in at least three threads that I can think of.

Get a new act. This one is old.

Didn't feel like answering did you? I didn't really expect you to change your non-answer to this problem. Talk about something getting old.

[Tony Szamboti]

Even I know this is total BS, and that's sad.

The problem here is nobody knows what you know as you don't ever make a technical comment. You are apparently just a cheerleader here.

[Grizzly Bear]

Didn't feel like answering did you?
Every question you have asked has been answered to the point of absurdity. I gave you this:
http://img22.imageshack.us/img22/5246/studyg.jpg

when you put on your other shenanigans... I expect you to either flat out deny this or "disappear" for a while until the "heat clears". It is old, and at a point where it's predictable.

[rwguinn]

In a small way, due to his errors cancelling out, Tony is correct--there is no APPARENT decelleration of the falling mass when it hits the lower block.
That is because the available work (energy) is so great that only a small portion of is required to exert a force great enough to fail the floor structure below it.
Acceleration is Delta(V)/delta(t).
Force is Acceleration times Mass, or M*(DV/Dt)
Let's use Tony's 68 million lb. at 12 feet of fall, it has a velocity of 24 ft/sec under 1 g. Let's call it 3/4 g, just for grins, and we get 18 ft/sec
We can handle 29 million lb per floor.
Quickly, lets see the time required to bring that baby to a full stop, assuming linear acceleration...
Then look at the time required to generate a 29 million lb load using a 1 ft/sec change in velocity...
My, that is a short time...

[Newtons Bit]

Mr. Szamboti, what's the punching shear capacity of the slab (assume a 14x14 loading area)?

I'll give you a hint: it's not much. I also have a hard time believing the floor could support a static weight of approximately 580 psf. That's...ridiculous. Even if NIST said it.

[Hokulele]

No, I am not ignoring it. Amplified loading requires deceleration and there was none, which is what you seem to be forgetting.


There is a difference between deceleration and reduced acceleration.

[Tony Szamboti]

Every question you have asked has been answered to the point of absurdity. I gave you this:
http://img22.imageshack.us/img22/5246/studyg.jpg

when you put on your other shenanigans... I expect you to either flat out deny this or "disappear" for a while until the "heat clears". It is old, and at a point where it's predictable.

I asked you to provide an estimate of what the acceleration should have been with some basis, and all you do is show pictures and try to say things have already been explained.

Since Dr. Bazant's jolt theory was shown to be incompatible with observation I haven't seen any of you who support the natural collapse hypothesis provide a calculated estimate with a basis for the observed acceleration and actual resistance experienced.

[Tony Szamboti]

Mr. Szamboti, what's the punching shear capacity of the slab (assume a 14x14 loading area)?

I'll give you a hint: it's not much. I also have a hard time believing the floor could support a static weight of approximately 580 psf. That's...ridiculous. Even if NIST said it.

After the columns punch through the floor slab (assuming all of the columns miss each other) what has to happen next?

As for floor load capacity it sounds like you have an argument with the NIST also. Why don't you do the calculations yourself instead of just being incredulous? All of the structural information on the floors outside of the core is publicly available.

[triforcharity]

Do you have any basis for what you are saying or is it just what you feel?

Professional training in collapses due to fire.

Would it have been possible for the top section to hit the bottom section exactly square?? Highly doubtfull. Most collapses from fire do not cause a 100% even collapse. Not even close.

I also feel, again, because of my professional experience, and my first hand knowledge of the events of 9/11, that it was anything but an even collapse. It tilted. There is no arguing this. Hell, even some of the guys back at the firehouse, were we all regrouped after the second collapse, said they could see the tilt. Why do you deny it was there?? I am sure someone has already provided evidence of the tilt.

Why do you deny it was there??


ETA:

BTW, why do you insist on using a static load, when (I believe, maybe Mackey can correct me) you should be caalulation the dynamic load.

[Grizzly Bear]

Since Dr. Bazant's jolt theory was shown to be incompatible with observation
Old news Tony... I honestly don't care that you are incapable of reading that model correctly. Most people are able to read it once and understand the purpose of that model and move on. You, Heiwa, et al aren't in that camp.

[Tony Szamboti]

Professional training in collapses due to fire.

Would it have been possible for the top section to hit the bottom section exactly square?? Highly doubtfull. Most collapses from fire do not cause a 100% even collapse. Not even close.

I also feel, again, because of my professional experience, and my first hand knowledge of the events of 9/11, that it was anything but an even collapse. It tilted. There is no arguing this. Hell, even some of the guys back at the firehouse, were we all regrouped after the second collapse, said they could see the tilt. Why do you deny it was there?? I am sure someone has already provided evidence of the tilt. Why do you deny it was there??


I do not deny that the upper section of the building tilted. The argument is about when it tilted. The video evidence shows the tilt occurred after the upper block had vertically descended several stories.


ETA:

BTW, why do you insist on using a static load, when (I believe, maybe Mackey can correct me) you should be caalulation the dynamic load.
It sounds like you didn't fully understand what I said earlier. A dynamic load requires deceleration and we know none occurred.

[Newtons Bit]

After the columns punch through the floor slab (assuming all of the columns miss each other) what has to happen next?

Gee, I don't know, punch through and keep going? Some of the columns would knock the truss itself out. In other areas, the trusses would lose composite properties with the deck itself and collapse: I imagine it to be exceedingly chaotic.

As for floor load capacity it sounds like you have an argument with the NIST also. Why don't you do the calculations yourself instead of just being incredulous? All of the structural information on the floors outside of the core is publicly available.

I don't have access to any of the connection details or the truss details. My incredulity stems from a knowledge of building codes and what floor slabs are typically designed to handle. A typical office building has a design (floor) live load of 40 to 60 psf with an additional 15 psf for partition loading. There's also a factor of safety of around 1.77 for this live load in bending and 2.13 in shear. The design capacity would need to be 327psf (minus 50 or so for dead load). That's absurd. It would be a gigantic waste of money if the designers did this.

[Hokulele]

I do not deny that the upper section of the building tilted. The argument is about when it tilted. The video evidence shows the tilt occurred after the upper block had vertically descended several stories.


What would induce a tilt after collapse initiation?

[Sam.I.Am]

Mr. Szamboti, what's the punching shear capacity of the slab (assume a 14x14 loading area)?

I'll give you a hint: it's not much. I also have a hard time believing the floor could support a static weight of approximately 580 psf. That's...ridiculous. Even if NIST said it.

That was their admittedly most conservative estimate. If the weight was carefully and evenly applied (I'd imagine that the easiest way to do this would be a 10 foot high tank full of water slowly filling up I guess) then the intact structure should fail at or about 580 psf. If that same tank was reduced in half and dropped 10 feet in a perfectly level fashion they estimated that that was the approximate failure point of an intact floor.

Of course the floors directly below the collapse points weren't intact and the upper blocks didn't fall levelly so their estimates mean squat other than as a mental exercise.

I think that they used the most conservative estimate in their Dec 2007 FAQ because it helped to explain to laymen that, no matter what, the upper blocks were going to exceed that estimate by a great deal, which was why they didn't bother modeling anything after the collapse initiation.

[R.Mackey]

Mr. Szamboti, what's the punching shear capacity of the slab (assume a 14x14 loading area)?

I'll give you a hint: it's not much. I also have a hard time believing the floor could support a static weight of approximately 580 psf. That's...ridiculous. Even if NIST said it.

I'm too lazy to verify this rigorously right now, but I believe 580 psf is what it works out to be to fail the truss seats, not to buckle the trusses themselves. That rating is something closer to 300 psf, and of course we need to take the self-weight of the floors into account as well.

The places to look will be NCSTAR1-6B, the destructive truss evaluation under load, and Appendix B to NCSTAR1-6D, where they evaluate the "pancaking hypothesis."

And, of course, none of this actually matters to the question under discussion. Whatever the maximum load is, it's not enough, nor are the floors of concern intact, nor are they being hit squarely and simultaneously. The whole discussion is moot.

ETA: Bah, I'm bored. From NCSTAR1-6B, Table 4-14 the maximum rated loading was 106 PSF for the short-span trusses, plus 48 PSF of self-weight. From this, 300 PSF is somewhat optimistic but plausible as a true ultimate load. 500+, I don't buy that either.

[beachnut]

The problem here is nobody knows what you know as you don't ever make a technical comment. You are apparently just a cheerleader here.
That was more technical than your delusional real-cd-deal for the collapse. You failed to apply engineering skills to the collapse of the WTC towers. Bad news as you claim to be an engineer. Toot, toot, jolt, jolt, …

The truth is you will never present a solid piece of work to prove your real-cd-deal on 911. The engineering papers on 911 you published at the 911truth woo journal will never be in real engineering journals save examples of paranoid delusions and junk science.

I forgot what twinstead's field was, but he correctly understands how the towers failed, and you as a super-nano-trained engineer have no clue. Cheer on twinstead for rational, skeptical, critical thinking. Sad an engineer supports fantasy, and twinstead supports reality. Irony is a constant for truthers.
If there was a Pulitzer Prize for delusional conspiracy theories you super-nano-thermite guys could apply.



The 29 million pounds a single floor can hold is just the floor as attached to the core and the shell. If a load reaches the floor in excess, the floor instantly fails and you can model the collapse as a momentum transfer and get very close the collapse time of floors as seen on 911. Oops, no real-cd-deal here, just the inability of a not-a-structural-engineer making up dumb ideas to support some delusional inside job fantasy that is 8 years old.




http://wtc.nist.gov/pubs/factsheets/faqs_12_2007.htm (http://wtc.nist.gov/pubs/factsheets/faqs_12_2007.htm)

1. Was there enough gravitational energy present in the World Trade Center Towers to cause the collapse of the intact floors below the impact floors? Why was the collapse of WTC 1 and 2 not arrested by the intact structure below the floors where columns first began to buckle?
Yes, there was more than enough gravitational load to cause the collapse of the floors below the level of collapse initiation in both WTC Towers. The vertical capacity of the connections supporting an intact floor below the level of collapse was adequate to carry the load of 11 additional floors if the load was applied gradually and 6 additional floors if the load was applied suddenly (as was the case). Since the number of floors above the approximate floor of collapse initiation exceeded six in each WTC Tower (12 and 29 floors, respectively), the floors below the level of collapse initiation were unable to resist the suddenly applied gravitational load from the upper floors of the buildings. Details of this finding are provided below:
Consider a typical floor immediately below the level of collapse initiation and conservatively assume that the floor is still supported on all columns (i.e., the columns below the intact floor did not buckle or peel-off due to the failure of the columns above). Consider further the truss seat connections between the primary floor trusses and the exterior wall columns or core columns. The individual connection capacities ranged from 94,000 lb to 395,000 lb, with a total vertical load capacity for the connections on a typical floor of 29,000,000 lb (See Section 5.2.4 of NIST NCSTAR 1-6C). The total floor area outside the core was approximately 31,000 ft2, and the average load on a floor under service conditions on September 11, 2001 was 80 lb/ft2. Thus, the total vertical load on a floor outside the core can be estimated by multiplying the floor area (31,000 ft2) by the gravitational load (80 lb/ft2), which yields 2,500,000 lb (this is a conservative load estimate since it ignores the weight contribution of the heavier mechanical floors at the top of each WTC Tower). By dividing the total vertical connection capacity (29,000,000 lb) of a floor by the total vertical load applied to the connections (2,500,000 lb), the number of floors that can be supported by an intact floor is calculated to be a total of 12 floors or 11 additional floors.
This simplified and conservative analysis indicates that the floor connections could have carried only a maximum of about 11 additional floors if the load from these floors were applied statically. Even this number is (conservatively) high, since the load from above the collapsing floor is being applied suddenly. Since the dynamic amplification factor for a suddenly applied load is 2, an intact floor below the level of collapse initiation could not have supported more than six floors. Since the number of floors above the level where the collapse initiated, exceeded 6 for both towers (12 for WTC 1 and 29 for WTC 2), neither tower could have arrested the progression of collapse once collapse initiated. In reality, the highest intact floor was about three (WTC 2) to six (WTC 1) floors below the level of collapse initiation. Thus, more than the 12 to 29 floors reported above actually loaded the intact floor suddenly.

[Tony Szamboti]

That was more technical than your delusional real-cd-deal for the collapse. You failed to apply engineering skills to the collapse of the WTC towers. Bad news as you claim to be an engineer. Toot, toot, jolt, jolt, … [/FONT][/COLOR]

The truth is you will never present a solid piece of work to prove your real-cd-deal on 911. The engineering papers on 911 you published at the 911truth woo journal will never be in real engineering journals save examples of paranoid delusions and junk science.

I forgot what twinstead's field was, but he correctly understands how the towers failed, and you as a super-nano-trained engineer have no clue. Cheer on twinstead for rational, skeptical, critical thinking. Sad an engineer supports fantasy, and twinstead supports reality. Irony is a constant for truthers.
If there was a Pulitzer Prize for delusional conspiracy theories you super-nano-thermite guys could apply.
Hey Beach, it would be interesting to hear yours and twinstead's explanation for how a failure of one wall on a structure with four deep sides with interior support can cause an overturn of that structure.

[funk de fino]

Didn't feel like answering did you? I didn't really expect you to change your non-answer to this problem. Talk about something getting old.

You are a proven liar Tony. No-one has to continue reading or replying to your bunk

[GlennB]

Hey Beach, it would be interesting to hear yours and twinstead's explanation for how a failure of one wall on a structure with four deep sides with interior support can cause an overturn of that structure.

It didn't 'overturn', it collapsed. Crash your car just right and it might 'overturn'.

And it would be interesting to hear whether you view the failure of a single exterior wall as being the only structural failure at that point in time. Or was it symptomatic of failures also occuring inside the building?

[Edx]

Can someone tell me if truthers have ever explained a mechanism that would pull in on the perimeter columns?

[Tony Szamboti]

It didn't 'overturn', it collapsed. Crash your car just right and it might 'overturn'.

And it would be interesting to hear whether you view the failure of a single exterior wall as being the only structural failure at that point in time. Or was it symptomatic of failures also occuring inside the building?

The NIST has no evidence for temperatures high enough to cause core failure. You are welcome to try and get a physical model to overturn even with a large number of core columns missing. Try it.

What is additionally interesting about the exterior failure they claim for the south wall is that they couldn't get their model to generate the forces to cause the failure, so they simply took the liberty of adding artificial pull-in forces. They had to do that even though they had removed the bridging trusses between the main trusses going from the core to the perimeter to allow the main trusses to sag vertically. The inability of the model to actually produce the failure without manipulation would cause it to be rejected by any engineering failure anlysis board in any company which needs to come up with legitimate solutions to survive.

The actual house of cards is the NIST report and it's "poised for collapse" contention and their reliance on Dr. Bazant's now disproven hypothesis of a powerful impact.

The lack of objectivity and loyalty to an illogical and impossible hypothesis by some is simply amazing. They might as well just say "the planes hit the buildings and they couldn't take it and...and... they just fell". That would not be far from where the NIST report is now, especially without Bazant's theory having any credence.

[Tony Szamboti]

Can someone tell me if truthers have ever explained a mechanism that would pull in on the perimeter columns?

It would certainly happen if core columns completely failed in some way and pulled on the perimeter wall through the trusses. The problem for a natural occurrence there is that there is no evidence of temperatures high enough to cause it.

[twinstead]

The problem here is nobody knows what you know as you don't ever make a technical comment. You are apparently just a cheerleader here.

I didn't realize that technical comments were a prerequisite for posting on this forum. I'll have to look in to that.

Being a layman, I know only what the general consensus of experts have said on the issue. That's all I have to go by. When people (and not just on this forum) whom I believe are perfectly qualified tell me that you don't know what you're talking about, my first instinct is to believe them. But, being a skeptic, I'm willing to hear from others who are experts as well. Let's just say your side of the issue is underrepresented and keep it at that.

[GlennB]

It would certainly happen if core columns completely failed in some way and pulled on the perimeter wall through the trusses. The problem for a natural occurrence there is that there is no evidence of temperatures high enough to cause it.

Given that they were bowed for some minutes this leaves us with the astonishing revelation that the core columns were cut, but that the exterior walls bravely supported the entire upper core. Leaving it hanging there, suspended, by the floor spans. Laughing dogs are inadequate at this point.

Having noted your evasion of my previous question, would I be wasting my time asking you how you believe the collapse was procured? Bearing in mind the absence of deafening explosions at the point of collapse initiation, and all that other tricky stuff.

[Grizzly Bear]

Having noted your evasion of my previous question, would I be wasting my time asking you how you believe the collapse was procured? Bearing in mind the absence of deafening explosions at the point of collapse initiation, and all that other tricky stuff.

Szamboti on Kevin Barrett's radio show, 10/30/07:

The way the towers were really brought down was a series of 3-story controlled demolitions. Around 25 to 30 controlled demolitions every three stories.

Look at any standard controlled demolition. Look at building 7. Look at the tremendous uh, clouds. You know, the pyroclastic surge after that dropped. Well, that was happening every three stories in the towers. That's why you get all that pulverization. It wasn't just the explosives either. The potential energy itself. Every three stories. Continuously. Is why there was so much pulverization in those towers.

...There's no doubt that there's an energy deficit.

Barrett: a hundred times as much energy would have been required to pulverize it, as was there for gravity.

SZ: There's no question. I just reviewed a paper along those lines, and the guy shows that. The PhD from Australia. So, there's no doubt that there was explosives.

There is an energy deficit in expanding those clouds. That's really where the energy deficit comes in.


Those banana peel plumes we see sure do look like they were due to explosives. Try to explain their upward movement with a gravity only collapse. They are narrow and appear to emanate from point like sources not a pressure wave. When standard controlled demolitions are done and the building falls to the ground the cloud is wide and diffuse not narrow.

No matter who you think did it, the towers were taken down every third floor in a series of controlled demolitions from the top down and those plumes are from explosives going off on the floors just below the collapse zone.

............................
.................................................. ...
.......
.
.

[GlennB]

Szamboti on Kevin Barrett's radio show, 10/30/07:



Thanks, I'd somehow missed that. Or maybe my brain refused to register it. He was talking "pyroclastic" and "expanding cloud energy deficit" as recently as October 2007? Is he a Hoffmanian?

Mr Szamboti - do you still adhere to those beliefs?

[tsig]

Szamboti on Kevin Barrett's radio show, 10/30/07:





............................
.................................................. ...
.......
.
.

The energy was just dust in the wind.

[RedIbis]

You are a proven liar Tony. No-one has to continue reading or replying to your bunk

Except for you apparently.

[Newtons Bit]

It would certainly happen if core columns completely failed in some way and pulled on the perimeter wall through the trusses. The problem for a natural occurrence there is that there is no evidence of temperatures high enough to cause it.

600 degree fires were all that was required. It's very plausible. Furthermore, there was plenty of evidence of columns that had experienced heat in excess of this. However, the marking that would identify where they would have been in the structure were also removed. The canard that there is no evidence for this range of temperature has been long debunked.

[Sam.I.Am]

Try to explain their upward movement with a gravity only collapse.

http://img91.imageshack.us/img91/7406/f8rob2687545.png

[Newtons Bit]

I'm too lazy to verify this rigorously right now, but I believe 580 psf is what it works out to be to fail the truss seats, not to buckle the trusses themselves. That rating is something closer to 300 psf, and of course we need to take the self-weight of the floors into account as well.

The places to look will be NCSTAR1-6B, the destructive truss evaluation under load, and Appendix B to NCSTAR1-6D, where they evaluate the "pancaking hypothesis."

And, of course, none of this actually matters to the question under discussion. Whatever the maximum load is, it's not enough, nor are the floors of concern intact, nor are they being hit squarely and simultaneously. The whole discussion is moot.

ETA: Bah, I'm bored. From NCSTAR1-6B, Table 4-14 the maximum rated loading was 106 PSF for the short-span trusses, plus 48 PSF of self-weight. From this, 300 PSF is somewhat optimistic but plausible as a true ultimate load. 500+, I don't buy that either.

I suspected it to be something like that. There's absolutely no way it would have an actual capacity of 500+psf.

[Tony Szamboti]

600 degree fires were all that was required. It's very plausible. Furthermore, there was plenty of evidence of columns that had experienced heat in excess of this. However, the marking that would identify where they would have been in the structure were also removed. The canard that there is no evidence for this range of temperature has been long debunked.

I would agree that 600 to 650 degree C steel core column temperatures could be enough to cause their collapse if 20% of them are missing from impact. Even though the North Tower collapse initiation occurred on a floor with little impact damage I would still allow for it.

However, I know of no evidence for it and since you state that there is, you are obligated to provide a citation for it.

It is also just a bare assertion that column locations couldn't be ascertained since the markings were all destroyed in the collapse. Many of the markings were embossed on the Twin Tower steel and even if they were somehow removed the wall thickness and sizing would allow locations to be determined. There is really no excuse for not saving the steel for a forensic analysis.

[Furcifer]

There is really no excuse for not saving the steel for a forensic analysis.

What arrogance. This is your opinion established well after the fact, and in the face of all verify able evidence.

There is an excuse, it's called reality.

[Seymour Butz]

I do not deny that the upper section of the building tilted. The argument is about when it tilted. The video evidence shows the tilt occurred after the upper block had vertically descended several stories.




LIAR.

http://wtc.nist.gov/pubs/NISTNCSTAR1-6DDraft.pdf

WTC 1:

The section of the building above the impact zone tilted to the south (observed at about 8°)
as column instability progressed rapidly from the south wall along the adjacent east and west walls (see
Fig. E–11), resulting in increased gravity load on the core columns. The release of potential energy due
to downward movement of building mass above the buckled columns exceeded the strain energy that
could be absorbed by the structure. Global collapse ensued.

WTC 2:

The section of the building above the impact zone tilted to the east and south (observed at about 7° to 8°
to east and about 3° to 4° to south, Fig. E–16) as column instability progressed from the east wall to the
adjacent south and north walls. The release of potential energy due to downward movement of the
building mass above the buckled columns exceeded the strain energy that could be absorbed by the
structure. Global collapse ensued.



In both cases, they tilt 7-8 degrees.... THEN global collaose unsued.

[Mangoose]

Hey Beach, it would be interesting to hear yours and twinstead's explanation for how a failure of one wall on a structure with four deep sides with interior support can cause an overturn of that structure.

It [gradual inward bowing of outer columns] would certainly happen if core columns completely failed in some way and pulled on the perimeter wall through the trusses.

If you truly believe that the gradual inward bowing of the outer columns occurred via the complete failure of the core, then why do you mention the interior support provided by the core as a mitigating factor in the collapse?

[Seymour Butz]

The NIST has no evidence for temperatures high enough to cause core failure.


Nor do they say that high temps caused core failure.

Strawman much?

[Seymour Butz]

I would agree that 600 to 650 degree C steel core column temperatures could be enough to cause their collapse if 20% of them are missing from impact. Even though the North Tower collapse initiation occurred on a floor with little impact damage I would still allow for it.

However, I know of no evidence for it and since you state that there is, you are obligated to provide a citation for it.

Another strawman.

http://wtc.nist.gov/pubs/NISTNCSTAR1-6DDraft.pdf

Unloading of Core. Temperatures in the core area rose quickly, and thermal expansion of the core was
greater than the thermal expansion of the exterior walls in early stages of the fire. This increased the
gravity loads in the core columns until 10 min after impact. The additional gravity loads from adjacent
severed columns and high temperatures caused high plastic and creep strains to develop in the core
columns in early stages of the fire. More columns buckled inelastically due to high temperatures. Creep
strain continued to increase to the point of collapse. By 30 min, the plastic-plus-creep strains exceeded
thermal expansion strains. Due to high plastic and creep strains and inelastic buckling of core columns,
the core columns shortened, and the core displaced downward. At 100 min, the downward displacement
of the core at Floor 99 became 2.0 in. on the average.
The shortening of core columns was resisted by the hat truss, which unloaded the core with time and
redistributed the gravity loads from the core to the exterior walls. As a result, the north, east, south, and
west walls at Floor 98 carried about 12 percent, 27 percent, 10 percent, and 22 percent more gravity loads,
respectively, at 80 min than the state after the impact, and the core carried about 20 percent less loads.
The net increase in the total column load on the south wall, where exterior wall failure initiated, was only
about 10 percent due to core downward displacement. At 80 min, the total core column loads reached its
maximum. As the floor pulled in starting at 80 min on in the south side, the south exterior wall began to
shed load to adjacent walls and the core.



It looks like Tony never read and/or understood NIST's collapse argument.

What a surprise.

[Grizzly Bear]

Or it could be that like every other office fire the WTC had the same combustible fuels available and burned like every other building. Every other office fire with the same types of fuel burns in excess of 800oC. The things that sat the WTC apart from every other fire is that the ignition was on the order of several floors as opposed to a single point and they were consequently much larger than most other fires at the point of ignition.

[Tony Szamboti]

Or it could be that like every other office fire the WTC had the same combustible fuels available and burned like every other building. Every other office fire with the same types of fuel burns in excess of 800oC. The things that sat the WTC apart from every other fire is that the ignition was on the order of several floors as opposed to a single point and they were consequently much larger than most other fires at the point of ignition.

Air temperatures are not steel temperatures.

There simply is no evidence of HIGH steel temperatures in the core. The sad part is we would know precisely what happened had the steel been saved.

Why wasn't it?

[Tony Szamboti]

Another strawman.

http://wtc.nist.gov/pubs/NISTNCSTAR1-6DDraft.pdf

Unloading of Core. Temperatures in the core area rose quickly, and thermal expansion of the core was
greater than the thermal expansion of the exterior walls in early stages of the fire. This increased the
gravity loads in the core columns until 10 min after impact. The additional gravity loads from adjacent
severed columns and high temperatures caused high plastic and creep strains to develop in the core
columns in early stages of the fire. More columns buckled inelastically due to high temperatures. Creep
strain continued to increase to the point of collapse. By 30 min, the plastic-plus-creep strains exceeded
thermal expansion strains. Due to high plastic and creep strains and inelastic buckling of core columns,
the core columns shortened, and the core displaced downward. At 100 min, the downward displacement
of the core at Floor 99 became 2.0 in. on the average.
The shortening of core columns was resisted by the hat truss, which unloaded the core with time and
redistributed the gravity loads from the core to the exterior walls. As a result, the north, east, south, and
west walls at Floor 98 carried about 12 percent, 27 percent, 10 percent, and 22 percent more gravity loads,
respectively, at 80 min than the state after the impact, and the core carried about 20 percent less loads.
The net increase in the total column load on the south wall, where exterior wall failure initiated, was only
about 10 percent due to core downward displacement. At 80 min, the total core column loads reached its
maximum. As the floor pulled in starting at 80 min on in the south side, the south exterior wall began to
shed load to adjacent walls and the core.



It looks like Tony never read and/or understood NIST's collapse argument.

What a surprise.

I read it and understand it. Where is the evidence that the core columns buckled? Where is that steel?

There also wasn't enough load redistribution to the east and west walls to cause them to fail. In order to have the core put more stress on the perimeter the yield stress of the hat truss connections was artificially increased. Did you read and understand that part?

[Tony Szamboti]

LIAR.

http://wtc.nist.gov/pubs/NISTNCSTAR1-6DDraft.pdf

WTC 1:

The section of the building above the impact zone tilted to the south (observed at about 8°)
as column instability progressed rapidly from the south wall along the adjacent east and west walls (see
Fig. E–11), resulting in increased gravity load on the core columns. The release of potential energy due
to downward movement of building mass above the buckled columns exceeded the strain energy that
could be absorbed by the structure. Global collapse ensued.

WTC 2:

The section of the building above the impact zone tilted to the east and south (observed at about 7° to 8°
to east and about 3° to 4° to south, Fig. E–16) as column instability progressed from the east wall to the
adjacent south and north walls. The release of potential energy due to downward movement of the
building mass above the buckled columns exceeded the strain energy that could be absorbed by the
structure. Global collapse ensued.



In both cases, they tilt 7-8 degrees.... THEN global collaose unsued.

Please show the frame by frame analysis done by the NIST to show when the tilt occurred. Oh, you can't because they did not do that. It turns out they simply assert that the upper section tilted and then descended.

[Tony Szamboti]

What arrogance. This is your opinion established well after the fact, and in the face of all verify able evidence.

There is an excuse, it's called reality.

Not saving the steel from at least the fire affected areas of the towers smacks of a cover-up. That is reality.

[R.Mackey]

I would agree that 600 to 650 degree C steel core column temperatures could be enough to cause their collapse if 20% of them are missing from impact. Even though the North Tower collapse initiation occurred on a floor with little impact damage I would still allow for it.

However, I know of no evidence for it and since you state that there is, you are obligated to provide a citation for it.

Simulation provides plenty of evidence for it. Ergo, you lied.

You also need to take time into account. Creep is an essential ingredient of collapse, and this is confirmed by Purdue and Arup's results. More time available == lower temperatures required.

It is also just a bare assertion that column locations couldn't be ascertained since the markings were all destroyed in the collapse. Many of the markings were embossed on the Twin Tower steel and even if they were somehow removed the wall thickness and sizing would allow locations to be determined. There is really no excuse for not saving the steel for a forensic analysis.

If you actually read through NCSTAR1-3, you will see that even among pieces that were retrieved, a rather large fraction had all identifying marks obliterated. We reasonably expect this to happen more often in the initiation region, which was the most affected by both impact and fire, and at the very heart of the entire collapse. NCSTAR1-3 also describes what these marks were, and makes it quite plain how they could be confused. Not to mention, some parts, notably the core beams, were never marked in a reconstructible way to begin with.

So, in summary, who cares? Even if we had the components, you'd still be bitching about it. We know this because we have all the pieces from the Pentagon, and idiots are still whining about explosives there. Making you happy is not our problem.

[Tony Szamboti]

If you truly believe that the gradual inward bowing of the outer columns occurred via the complete failure of the core, then why do you mention the interior support provided by the core as a mitigating factor in the collapse?

I have a hard time with the lone photo the NIST has which purportedly shows only the south perimeter wall of WTC 1 bowing inward at 22 minutes prior to collapse. You should realize there is no video of this although the helicopters flying around the towers had video cameras on them.

Next the NIST could not get their model to generate the inward bowing so they had to add artificial pull-in forces to the perimeter columns. Their analysis is thus invalid here.

I actually think the perimeter columns on all four faces were pulled inwardly by a sudden massive core failure at initiation. It is what could have caused that massive core failure which should be the question. However, the NIST danced around that question, preferring to try and show that truss sagging could have caused one wall to bow inward and cause a complete collapse. They still involved the core in a secondary role, since one wall failing cannot cause a complete failure across the building. Their discussion of core column failures is not supported by any physical evidence.

I have proposed that people who can't see why removing one wall or even some of the core columns couldn't cause rotation should make themselves a four sided self supporting structure with equal length walls and some interior support. Remove one wall completely and see if it rotates.

I would say the NIST theory on collapse initiation is something along the lines of bovine skedaddle, to borrow a phrase used for b.s. by General Norman Schwarzkopf.

[Tony Szamboti]

Simulation provides plenty of evidence for it. Ergo, you lied.

You also need to take time into account. Creep is an essential ingredient of collapse, and this is confirmed by Purdue and Arup's results. More time available == lower temperatures required.



If you actually read through NCSTAR1-3, you will see that even among pieces that were retrieved, a rather large fraction had all identifying marks obliterated. We reasonably expect this to happen more often in the initiation region, which was the most affected by both impact and fire, and at the very heart of the entire collapse. NCSTAR1-3 also describes what these marks were, and makes it quite plain how they could be confused. Not to mention, some parts, notably the core beams, were never marked in a reconstructible way to begin with.

So, in summary, who cares? Even if we had the components, you'd still be bitching about it. We know this because we have all the pieces from the Pentagon, and idiots are still whining about explosives there. Making you happy is not our problem.

I would not be bitching for one minute if I were shown physical evidence for high steel temperatures due to fires on the core columns at the initiation zone and that they buckled in the collapse initiation.

You can't use obliteration as an excuse. The columns could have been identified by size and wall thicknesses.

The fact that you don't think something is fishy about the steel not being saved for a full forensic analysis is surprising for an engineer.

The Pentagon is an entirely different story from that of the towers. Please don't confuse the two.

[R.Mackey]

I have a hard time with the lone photo the NIST has which purportedly shows only the south perimeter wall of WTC 1 bowing inward at 22 minutes prior to collapse. You should realize there is no video of this although the helicopters flying around the towers had video cameras on them.

The photo in NIST is taken from a video. You know this to be true.

Next the NIST could not get their model to generate the inward bowing so they had to add artificial pull-in forces to the perimeter columns. Their analysis is thus invalid here.

Negative. The bowing is an input to the model, and it was observed directly. They needed to hypothesize a pull-in force to explain the bowing, but that pull-in force does not even appear in the collapse analysis.

It's also consistent with photographs of bowing floors.

I actually think the perimeter columns on all four faces were pulled inwardly by a sudden massive core failure at initiation. It is what could have caused that massive core failure which should be the question.

Impossible. The bowing precedes the collapse by eight minutes in the case of WTC 1, and about 25 minutes for WTC 2. You already know this.

I have have proposed that people who can't see why removing one wall or even some of the core columns make themselves a four sided self supporting structure with equal length walls and some interior support. Remove one wall completely and see if it rotates. You can even remove many of the core columns before removing the one wall.

The east and west walls have no ability whatsoever to resist a rotation to the south. That's the way the Towers were designed. Your proposition is useless.

I would say the NIST theory on collapse initiation is something along the lines of bovine skeedaddle to borrow a phrase used for b.s. by General Norman Schwarzkopf.

Sayeth the proven and unrepentant liar. How surprising.

[GlennB]

I would agree that 600 to 650 degree C steel core column temperatures could be enough to cause their collapse if 20% of them are missing from impact. Even though the North Tower collapse initiation occurred on a floor with little impact damage I would still allow for it.


OK. So if collapse was initiated by some form of CD to the core, why didn't the exterior columns get ripped inwards by the falling core in about ... oooh ... a second or so? Why did they bow inwards for several minutes?

[R.Mackey]

I would not be bitching for one minute if I were shown physical evidence for high steel temperatures due to fires on the core columns at the initiation zone and that they buckled in the collapse initiation.

Sure you wouldn't.

You can't use obliteration as an excuse. The columns could have been identified by size and wall thicknesses.

Nope. Far too much ambiguity. Another bald-faced lie for you, Tony. They're beginning to grow geometrically.

The fact that you don't think something is fishy about the steel not being saved for a full forensic analysis is surprising for an engineer.

Ad hominem, and totally stupid. We're talking about 200,000 tons of steel here -- enough to build two aircraft carriers. Furthermore, there are only a few, isolated fine points of contention left, so clearly the steel we have now puts us into the realm of diminishing returns.

You don't even have a hypothesis to test, so claiming we "need more steel" is putting the cart before the horse. Learn some basic science, and then come back.

[funk de fino]

Except for you apparently.

Says the coward who does not ask simple questions put to him but is happy to have a snark in this thread. How childish.

[funk de fino]

I have a hard time with the lone photo the NIST has which purportedly shows only the south perimeter wall of WTC 1 bowing inward at 22 minutes prior to collapse. You should realize there is no video of this although the helicopters flying around the towers had video cameras on them.

This is Tony in a nutshell. Someone who told lies about Silverstein has then made a snide comment as above.

[Mangoose]

I do not deny that the upper section of the building tilted. The argument is about when it tilted. The video evidence shows the tilt occurred after the upper block had vertically descended several stories.

What video evidence? Not any that I have seen.

http://img405.imageshack.us/img405/2857/aniv.gif http://img65.imageshack.us/img65/9404/output2.gif

Notice that the lean in the mast in the first video corresponds to the lean in the northwest corner of the upper block, which leans before there is any collapse on the North Face.

I have a hard time with the lone photo the NIST has which purportedly shows only the south perimeter wall of WTC 1 bowing inward at 22 minutes prior to collapse. You should realize there is no video of this although the helicopters flying around the towers had video cameras on them.

What lone photo? Please give the NIST photo number. I have at least three photos taken from a helicopter about six minutes before the collapse:

http://img65.imageshack.us/img65/8158/12758489.jpg

http://img65.imageshack.us/img65/3134/12451161.jpg

http://img223.imageshack.us/img223/9214/14534702.jpg

http://img405.imageshack.us/img405/2412/86239828.jpg

I actually think the perimeter columns on all four faces were pulled inwardly by a sudden massive core failure at initiation. It is what could have caused that massive core failure which should be the question.

You think wrong. Only the perimeter columns on the face where collapse initiated were pulled inward, and for quite some time prior to the collapse (see the photos above in the case of WTC 1).

[Furcifer]

Not saving the steel from at least the fire affected areas of the towers smacks of a cover-up. That is reality.

No it doesn't.Edited for civility. If it were many of us would be on your side. There was no need for a cover up.

[funk de fino]

I actually think the perimeter columns on all four faces were pulled inwardly by a sudden massive core failure at initiation. It is what could have caused that massive core failure which should be the question.

Bring evidence Tony, not made up stuff.

[rwguinn]

I would not be bitching for one minute if I were shown physical evidence for high steel temperatures due to fires on the core columns at the initiation zone and that they buckled in the collapse initiation.

You can't use obliteration as an excuse. The columns could have been identified by size and wall thicknesses.

The fact that you don't think something is fishy about the steel not being saved for a full forensic analysis is surprising for an engineer.

The Pentagon is an entirely different story from that of the towers. Please don't confuse the two.
Shows you have absolutely no practical Mechanical or Civil Engineering background at all .
There are centuries of data on the behavior of steel under every condition that can and/or has occurred on Earth. There are books FULL of that data. Heat transfer through air to steel and within steel itself are extremely well known, and can be modeled (Simulated) with FEM, by hand, and specialized programs with extreme accuracy.
How good are we at this? Well, most modern aircraft are flown before a single structural test is done. Most vehicles on the road were built and tested with very few modifications to the mathematical model-and we certainly do not do full-scale testing on a building--we model it, then build it.
These results are as repeatable as 1+1=2, or that pi=circumference/radius of a circle. Thinking the rules, characteristics, and material properties can change overnight, or on a whim, is the engineering equivalent to the geocentric universe

[Tony Szamboti]

What video evidence? Not any that I have seen.

The northwest corner and southwest corner fall simultaneously with smoke coming out of both wall simulataneously showing the building descended before the tilt. The antenna is not necessarily a good measure of what the building was doing. Look at the roof of the building itself by dragging the slider in full screen mode.

http://www.youtube.com/watch?v=y9-owhllM9k

[Tony Szamboti]

Negative. The bowing is an input to the model, and it was observed directly. They needed to hypothesize a pull-in force to explain the bowing, but that pull-in force does not even appear in the collapse analysis.



The east and west walls have no ability whatsoever to resist a rotation to the south. That's the way the Towers were designed. Your proposition is useless.



Sayeth the proven and unrepentant liar. How surprising.

With your taking liberties with your comments towards me here, I would hope you don't take offense if I say this is nothing more than bovine skedaddle either.

You have become an apologist for and purveyor of bovine skedaddle.

[R.Mackey]

With your taking liberties with your comments towards me here, I would hope you don't take offense if I say this is nothing more than bovine skedaddle either.

You have become an apologist for and purveyor of bovine skedaddle.

Naked Ad hominem, abusive. I'll take that as an admission of surrender.

[Seymour Butz]

Please show the frame by frame analysis done by the NIST to show when the tilt occurred. Oh, you can't because they did not do that. It turns out they simply assert that the upper section tilted and then descended.

I bet this won't satisfy you, will it twoof:

http://wtc.nist.gov/pubs/NISTNCSTAR1-6DDraft.pdf pg 306, or 368/472 of the pdf

Actual observations are summarized in Table 5–2, which are based on NIST’s examination of
photos and videos (NIST NCSTAR 1-5A).

10:28:18 : Smoke puff out of north edge and center of west wall; smoke and
debris clouds out of the north, east, and west walls on Floor 98. Fire
out of windows on the north, east, west, and south walls between
Floor 92 and Floor 98, and on Floor 104.

10:28:20 : WTC 1 began to collapse. First exterior sign of collapse was at
Floor 98. Rotation of at least 8 degrees to the south occurred before the
building section began to fall vertically under gravity.

[Tony Szamboti]

Shows you have absolutely no practical Mechanical or Civil Engineering background at all .
There are centuries of data on the behavior of steel under every condition that can and/or has occurred on Earth. There are books FULL of that data. Heat transfer through air to steel and within steel itself are extremely well known, and can be modeled (Simulated) with FEM, by hand, and specialized programs with extreme accuracy.
How good are we at this? Well, most modern aircraft are flown before a single structural test is done. Most vehicles on the road were built and tested with very few modifications to the mathematical model-and we certainly do not do full-scale testing on a building--we model it, then build it.
These results are as repeatable as 1+1=2, or that pi=circumference/radius of a circle. Thinking the rules, characteristics, and material properties can change overnight, or on a whim, is the engineering equivalent to the geocentric universe

It is not true for one minute that modern aircraft are flown before a single structural test is done. I work in the aerospace industry and can tell you that dynamic testing is done on every new design. FEM may preclude prototyping but it does not obviate the need for qualification.

In any failure analysis the actual failed material is the best evidence and you are way off base if you say that isn't true.

The fact that the steel from at least the fire affected areas wasn't saved smacks of a need to get rid of it and a cover up. The storage area for that steel would have only been about the size of a football field. There is no excuse whatsoever for not saving it.

[R.Mackey]

In any failure analysis the actual failed material is the best evidence and you are way off base if you say that isn't true.

Funny to see you say this. Failure analysis of the actual failed material shows absolutely no evidence of explosives -- shows quite incompatible failure modes, without exception -- yet you're still yakking.

The fact that the steel from at least the fire affected areas wasn't saved smacks of a need to get rid of it and a cover up. The storage area for that steel would have only been about the size of a football field. There is no excuse whatsoever for not saving it.

Yes, there is. It couldn't be identified. And that only refers to the core. They saved a great deal of the perimeter, the parts that could be identified, including a large fraction of the panels hit by aircraft.

You already know this, yet you keep talking. Why?

[Tony Szamboti]

Naked Ad hominem, abusive. I'll take that as an admission of surrender.

But according to you it is okay for you to frivolously call me a liar. You are acting like a "can dish it out but can't take it guy".

There is no surrender other than in your mind. You have not proven your case by a long shot and you have had many opportunities. The NIST report and your defense of it are simply bovine skedaddle.

[Tony Szamboti]

Funny to see you say this. Failure analysis of the actual failed material shows absolutely no evidence of explosives -- shows quite incompatible failure modes, without exception -- yet you're still yakking.



Yes, there is. It couldn't be identified. And that only refers to the core. They saved a great deal of the perimeter, the parts that could be identified, including a large fraction of the panels hit by aircraft.

You already know this, yet you keep talking. Why?

They saved less than 0.5% of the steel and you and the NIST want to use that to make claims where you want and then where it doesn't support your hypothesis, like with temperatures, claim that it wasn't enough to make a determination.

That is why I say the report is garbage time and so is your defense of it. You can't have it both ways. All of the steel from at least the six stories of the fire affected areas should have been saved and it certainly could have been identified due to size and wall thicknesses.

[R.Mackey]

But according to you it is okay for you to frivolously call me a liar. You are acting like a "can dish it out but can't take it guy".

There is no surrender other than in your mind. You have not proven your case by a long shot and you have had many opportunities. The NIST report and your defense of it are simply bovine skedaddle.

Nope, I never "frivolously" called you a liar. You are a liar. I documented it (http://forums.randi.org/showthread.php?postid=5168947#post5168947) in this other thread. You believe things that are in direct contravention of photographic evidence.

Thus, why should I care when you slander me?

[R.Mackey]

They saved less than 0.5% of the steel and you and the NIST want to use that to make claims where you want and then where it doesn't support your hypothesis, like with temperatures, claim that it wasn't enough to make a determination.

That is why I say the report is garbage time and so is your defense of it. You can't have it both ways. All of the steel from at least the six stories of the fire affected areas should have been saved and it certainly could have been identified due to size and wall thicknesses.

No, it couldn't all be identified. That's a lie.

But this bickering also obscures a more salient point, which is this: Just what the heck are you trying to say, anyway?

You're fussing because you have no evidence to back up the hypothesis you still haven't defined. You're implying, but not saying, that "if only" the steel was all recovered, it would show that you were right? Is that it?

Well, if that's so, then how come it wasn't recovered? Was it an accident, or was it on purpose?

You seem to be implying the latter. So, according to you and your delusions, FEMA, Fresh Kills, Dr. Astaneh, all these guys that looked at the steel, deliberately hid or recycled all the pieces that would prove you were right? How did they do that? How did they even know which pieces came from the impact and fire floors? It took NIST a concerted effort to even decipher the markings, and some of them even they couldn't figure out.

Why should we view this complaint of yours as anything but unbridled paranoia?

[Seymour Butz]

I would not be bitching for one minute if I were shown physical evidence for high steel temperatures due to fires on the core columns at the initiation zone and that they buckled in the collapse initiation.




Liar.

You'd do just what you're doing here and now.

Make false claims about NIST.

[rwguinn]

It is not true for one minute that modern aircraft are flown before a single structural test is done. I work in the aerospace industry and can tell you that dynamic testing is done on every new design. FEM may preclude prototyping but it does not obviate the need for qualification.

In any failure analysis the actual failed material is the best evidence and you are way off base if you say that isn't true.

The fact that the steel from at least the fire affected areas wasn't saved smacks of a need to get rid of it and a cover up. The storage area for that steel would have only been about the size of a football field. There is no excuse whatsoever for not saving it.
You don't have a clue who you're talking to, do you

[Tony Szamboti]

You don't have a clue who you're talking to, do you

Many of your comments are nothing but bluff and bluster and for that reason finally someone with whom I will have no further dealings.

[Newtons Bit]

I would agree that 600 to 650 degree C steel core column temperatures could be enough to cause their collapse if 20% of them are missing from impact. Even though the North Tower collapse initiation occurred on a floor with little impact damage I would still allow for it.

Not core columns, perimeter columns. Do you remember this thread?

However, I know of no evidence for it and since you state that there is, you are obligated to provide a citation for it.

Look here. There's plenty of evidence. (http://wtc.nist.gov)

It is also just a bare assertion that column locations couldn't be ascertained since the markings were all destroyed in the collapse. Many of the markings were embossed on the Twin Tower steel and even if they were somehow removed the wall thickness and sizing would allow locations to be determined.

And I'm sure many of the markings were done with paint, what's your point? None of the steel in any of the jobs I've ever worked on came to the site with engraved markings. It's always painted on.

The wall thickness means very little. The designers varied both wall thickness and yield strength of the columns. And if you knew more about how this structure works, you would also know that the columns at the ends of the walls were more highly stressed than the ones in the middle. This means that the wall thickness varied both in horizontal relation of the walls and vertically. There's no way to determine where it came from just from the wall thickness.

There is really no excuse for not saving the steel for a forensic analysis.

A forensic analysis to look for what?!?

[BasqueArch]

My bolding / underlining / brakets

Wrong #1 ================================================== =============================
TSzamboti. The floors outside the core could take a 29 million lb. vertical static load before failure and for the beams inside the core I would estimate an additional 15 million lbs. giving a total of 44 million lbs. per floor.

TSzamboti. As for the 29 million lbs. static load capacity for the floors outside of the core you will have to take that up with the NIST as that is the value they come up with also.

TSzamboti The floors outside of the core had a huge factor of safety. Read the NIST FAQ from December 2007.

TSzamboti. I told you earlier that the NIST calculated a 29 million lb. static load capacity for the floor system outside of the core on each story. My own calculations produced a similar value.


Wrong #1 - TS misrepresents what NIST said. The calculated static load capacity for the floor system was not 29 million lb.
From NIST:

“The individual connection capacities ranged from 94,000 lb to 395,000 lb, with a total vertical load capacity for the connections on a typical floor of 29,000,000 lb (See Section 5.2.4 of NIST NCSTAR 1-6C). The total floor area outside the core was approximately 31,000 ft2, and the average load on a floor under service conditions on September 11, 2001 was 80 lb/ft2. Thus, the total vertical load on a floor outside the core can be estimated by multiplying the floor area (31,000 ft2) by the gravitational load (80 lb/ft2), which yields 2,500,000 lb”

http://wtc.nist.gov/pubs/factsheets/faqs_12_2007.htm

I would expect a theologian to possibly claim to misunderstand this, but not repeatedly by a mechanical engineer intimately familiar with the issues.

Ultimate Strength Design = Design Load x Factor of Safety (or Load Factor) .

According to Skilling’s hand written calculations the Design Load for the tenant spaces outside the core was 42 lb/ft2 DL and 100 lb/ft2 LL (page 143 below) no FOS was indicated. This includes a floor LL of 100 lb/ft2, twice the required load, he may have used this 2x FOS as sufficient to cover any lesser possible floor FOS. I have not been able to find any primary source indicating if any FOS for any structural members was used. ETA: But for perimeter columns design he used 50 lb/ft2 floor load and took further LL reductions per code.

Assuming a FOS was added to Skilling’s calculations, the present NYC building codes require (page 116 below) a maximum of 1.4 DL FOS and 1.7 LL FOS giving us a total USD for the slabs of 229 lb/ft 2. The structural floor members and design are known, an engineer can calculate the actual ultimate strength.

http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201-1.pdf

229 lb/ ft2 (US) x 31,000 sf = 7.1 million lb ultimate strength for the outside of the core floor slab not 29 million lb.
Wrong #2 ================================================== ==============================

TSzamboti The upper block of WTC 1 weighed approximately 68 million lbs. , so even if all the connected columns magically missed each other after buckling, the first collision should have caused a much more significant resistance to acceleration than what is observed.

Wrong #2 WTC1 tilted 8 degrees, WTC2 tilted 25 degrees . It would be more magical if all the upper fractured columns hit the lower columns axially – (axial load - The resultant longitudinal internal component of force which acts perpendicular to the cross section of a structural member and at its centroid, producing uniform stress).

Wrong #3================================================ ===================================

TSzamboti. Where is your evidence for this? The perimeter columns needed lateral support from the floor system outside the core but it is unlikely that the three dimensional core required it. The core beam to column connections have not been made publicly available, so I don't know what basis you are using for your contention here.

Originally Posted by Tony Szamboti ...
However, the complete central core itself was fully braced within itselfand had a very high moment of inertia (or resistance to bending) due to it's 137 ft. x 87 ft. plan, which would allow it to be self-suporting over the height of the towers. It did not need lateral support from the floors and perimeter.

Wrong #3 - The core columns were laterally braced by the floors.

“In the as-designed drawings, there were strap anchors connecting the core columns to the concrete floor slab to provide lateral bracing to the columns. At floor 26 of WTC 1, the straps at column 901 were removed during a renovation project that was engineered by a firm other than Leslie E. Robertson Associates, R.L.L.P. (see Sec.2.5.4). The loss of the straps at this location was included in the model by releasing the column from the diaphragm in the direction of the straps.”See Figure 2.3 search “strap”
http://wtc.nist.gov/NCSTAR1/PDF/NCST...20Baseline.pdf

This core bracing argument is irrelevant as the falling upper displaced columns removed the core floor beams.

Wrong #4================================================ =====================================

TSzamboti The resistance observed was about 30 to 35% of gravity so if you can do the simple math for just the floor resistance you will see there is a problem.

TSzamboti It sounds like you didn't fully understand what I said earlier. A dynamic load requires deceleration and we know none occurred.

TSzamboti The upper block of WTC 1 weighed approximately 68 million lbs. ...the first collision should have caused a much more significant resistance to acceleration than what is observed.

TSzamboti In the case of WTC 1 there is no deceleration and velocity loss. The upper block just accelerates at 65 to 70% of the rate of gravity throughout the entire nine stories it could be measured.
So where does the overload come from?

Wrong#4 - "I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question."- Babbage

Half of TS's statements are right and they contradict the other half.

With how much force did each of the upper columns hit the WTC1 floor slab below?

1) Area of columns footprint above 82nd floor per story = (236 perimeter columns x 1.36 ft2 ea.) + (47 core columns- WF rolled shape- x 1.78 ft2 ea) = 405 sf of total column area.

2) (not including roof) Load per square foot of column footprint = 42,800 ft2 per floor x 80 lb/ft2 actual load = 3,424,000 lb x 13 floors = 44,512,000 total lbs / 405 sf column area = 109,900 lb/ft2 x 2 dynamic load factor for 12 ft ht per NIST= 219,800 lb /ft2 equivalent static load per column ft2 landing 283 times per floor on 229 lb/ft2 ultimate slab load.

3) Answer 219,000 lb/ft2 column landing on 229 lb/ft2 ultimate slab capacity 283 times.

Questions:
1) Will the slab arrest the collapse of the floors above.
2) Will there be a perceptible "Jolt" at impact.

The collapse of the upper part of Tower1 was 12.82 sec. or 65.5% slower than freefall (7.74 sec.). The collapse of the upper part of Tower2 was 10.49 sec. or 47.3% slower than freefall (7.71 sec.) according to the Lamond-Doherty seismic records. -Bazant.

Wrong #5 ================================================== ==================================

TSzamboti I do not deny that the upper section of the building tilted. The argument is about when it tilted. The video evidence shows the tilt occurred after the upper block had vertically descended several stories.

Wrong#5 - There is no argument,the visual facts are conclusive, here it is again:

WTC 1 shot from the west showing tilt to south at start of collapse.
http://www.youtube.com/watch?v=YHCeRYreMp8

=================================================
You’ve repeatedly misrepresented what NIST said. Why did you expect to get away with this.

How can you stand being so wrong so often.

It’s over Szamboti. All your talking points are wrong.


--------------------------------------------------------------------------------------
You can't reason someone out of something they were not reasoned into - Swift

[Mangoose]

The northwest corner and southwest corner fall simultaneously with smoke coming out of both wall simulataneously showing the building descended before the tilt. The antenna is not necessarily a good measure of what the building was doing. Look at the roof of the building itself by dragging the slider in full screen mode.

http://www.youtube.com/watch?v=y9-owhllM9k

And as I pointed out with my animations, the tilt had already started long before "smoke [came] out of both wall[s] simultaneously". The antenna is informative because its lean and the lean of the northwest edge of the building occur together at a similar angle. Again, the lean can be seen here before floor collapse occurs on the North Face:

http://img405.imageshack.us/img405/2857/aniv.gif

And once the floor collapse occurs, we can see the lean of the northwest edge of the upper block continuing in concert with the leaning antenna mast:

http://img515.imageshack.us/img515/3602/lean.jpg

The descent of the mast also shows that the lean begins even before the North Face roofline falls:

http://img65.imageshack.us/img65/9404/output2.gif

That is because the lean has begun prior to the failure of the exterior columns of the North Face (the face opposite of where collapse initiation occurs). Videos of the WTC2 collapse similarly show stresses on the North Face of WTC2 progressing westward to the West Face (the face opposite of collapse initiation) before the latter finally undergoes collapse.

I notice you had nothing to say about the WTC1 bowing columns evidence I presented in my last post.

[BasqueArch]

And as I pointed out with my animations, the tilt had already started long before "smoke [came] out of both wall[s] simultaneously". The antenna is informative because its lean and the lean of the northwest edge of the building occur together at a similar angle. Again, the lean can be seen here before floor collapse occurs on the North Face:



Excellent thanks

[Hokulele]

What would induce a tilt after collapse initiation?


*Sigh*

I am completely invisible.

[AJM8125]

*Sigh*

I am completely invisible.

Ignored, avoided and disregarded too. That's no way to treat a lady, especially an evil one. ;)

[R.Mackey]

You know he's just going to say "nanotermites" or some other nonsense. Just as well that he doesn't answer -- it at least leaves the possibility, however unlikely, that he's still thinking about it.

[Hokulele]

I would even be happy with a simple "I don't know".

[rwguinn]

I would even be happy with a simple "I don't know".
That, you will never get from any of the jaq-asses

[Myriad]

You know, a very simple and obvious point has occurred to me, that I think everyone in the Truth Movement concerned about the collapse of the towers has overlooked.

(That seems very unlikely, doesn't it? And yet, Truthers frequently make claims of noticing simple and obvious things that every non Truther including experts in the relevant fields have overlooked. So, I see no reason to be shy about mine.)

And that is, that the collapses were threshold phenomena. So, like all threshold phenomena, they had to happen at moments when there can be no a priori certainty that they "should have" happened.

I'm going to start with an example to explain this. Imagine that I plan to suspend an empty bucket from a piece of string, and begin a slow trickle of water into the bucket.

Before I do this, I hire a consulting engineer and ask him to evaluate the set-up. The first question I ask is, "How full can the bucket get, without any risk of the string breaking?" I allow the engineer to test samples of the string, the weight of the bucket, the inner dimensions of the bucket, and so forth. The engineer determines a result and makes a mark on the inside wall of the bucket.

I then ask: "How full must the bucket be to make you absolutely certain that the string will break?" After more study, the engineer makes a second mark, indicating the point that he's confident the water will not reach before the string breaks.

If the engineer is competent, there will be some space between the two marks. That's because no matter how much the engineer tests the string and measures the bucket, there will be some unknowns. Some lengths of string will be slightly stronger than others. The water I use might be a bit harder or softer than he expects, and therefore slightly more or less dense. There must always be a margin of error between the point of certainty that failure will not occur, and the point of certainty that it must.

Now, let's assume the engineer has done the analysis correctly. When I run my experiment, what happens?

First, the water will rise above the first mark, and the string will not break. My string is unusually strong, stronger than the engineer said it would be.

Then, before the water reaches the second mark, the string will break. The string broke before the engineer was certain that it must. And we know from the earlier observation that this string was unusually strong. Someone must have sabotaged the string!

This, in fact, appears to be the gist of Tony's arguments in this thread, and in general. Tony has not denied that, in the general case, the damage from an airplane crash and the heat from a fire can weaken a steel structure. As far as I can tell he accepts the notion that a steel structure that's weakened sufficiently will collapse. The problem, in a nutshell, appears to be that each collapse occurred before it became a certainty that a collapse must occur.

He regards that as suspicious, or at least is trying very hard to make that appear suspicious. No one can prove a priori, with absolute certainty, that the towers had suffered sufficient structural compromise to cause a collapse at that moment. Therefore, someone must have sabotaged the towers.

That is exactly parallel to the string broke before the engineer who analyzed the scenario was certain it would. Someone must have sabotaged the string!

The simple and obvious reality is, threshold failure in deteriorating conditions never waits until failure is 100% provably guaranteed to occur, before occurring. (The exception is in movies, where when a rope slowly breaks strand by strand under a load, the last remaining strand no matter how thin will still support the entire load, often until just a moment after the load is removed). So threshold failures in deteriorating conditions will always, every single time, be "suspicious" in that way -- at least, to those determined to portray them so.

Respectfully,
Myriad

[triforcharity]

Myriad,

You ROCK!! What a simple way to explain "margin of error", Hell, even I understood it, and I am not a scientist.

[GlennB]

OK. So if collapse was initiated by some form of CD to the core, why didn't the exterior columns get ripped inwards by the falling core in about ... oooh ... a second or so? Why did they bow inwards for several minutes?

TS skipped this too. I thought it was a pertinent point. Ah well.

[Hokulele]

TS skipped this too. I thought it was a pertinent point. Ah well.


Join me over in the invisible people corner.

[GlennB]

Join me over in the invisible people corner.

Who said that ?????

[Hokulele]

*Shoots a spitball at GlennB*

[Sam.I.Am]

Myriad,

You ROCK!! What a simple way to explain "margin of error", Hell, even I understood it, and I am not a scientist.

I had a tl:dr post going on about this but I deleted it. To keep it short I was going to point out that Myriad was mostly right but also slightly wrong. You can accurately predict failure but it costs so much to do so that only large entities with huge budgets can do the pre-engineering, pre-testing and followup quality assurance inspections (pre and post construction) to get to that level of accuracy. I've been involved in doing both by mostly writing QA packages documenting each step in minutia and as a QA inspector where I had to document each step and couldn't deviate one iota from the testing procedures deliniated in the paperwork given me.

Take that as you may...

[archis]

About one thing I am very suprised.
People, engineers debate about calculations, give facts about structural desing and in same time nobady has structual drawings or they arent published (why???). I really have hard time to check these claims:

1) Core isnt braced at all. I think this is a law in structural desgin that at least lift
shaft should be braced aginst horizontal loads.
2) The only thing that gives side lateral support to core columns are trusses. Thats unbelieveble.
3) The only construction that takes horizontal loads are facede column construction. Dont know how the force manages to get from ( from facede wich the winds blows) to facedes (stiffness diafragms) who are parralllel to force vector.

[Hokulele]

About one thing I am very suprised.
People, engineers debate about calculations, give facts about structural desing and in same time nobady has structual drawings or they arent published (why???).


Because they are the intellectual property of the design firm, not the government, nor the general public.

[GlennB]

*Shoots a spitball at GlennB*

This is why Szamboti ignores you. You can spit across 12 time zones.
You missed, by the way. The dog got a bit of a shock though.

[Dave Rogers]

The floors outside the core could take a 29 million lb. vertical static load before failure and for the beams inside the core I would estimate an additional 15 million lbs. giving a total of 44 million lbs. per floor. The upper block of WTC 1 weighed approximately 68 million lbs., so even if all the connected columns magically missed each other after buckling, the first collision should have caused a much more significant resistance to acceleration than what is observed.

At least you don't dispute that the floors couldn't take the weight. The rotation of the other block - which, if you recall, I showed had already reached about 2º before the roofline had dropped by more than a quarter of a storey - would smear out the effect of a column-on-floor impact just as much as the effect of a column-on-column impact, and for the same reason: once the block is rotated, the columns strike the floor sequentially rather than simultaneously. I would go over the effect of vector addition of forces and the result that there is at no time a deceleration of the upper block, but Tony's repeatedly demonstrated his inability to follow this argument.

Where is your evidence for this? The perimeter columns needed lateral support from the floor system outside the core but it is unlikely that the three dimensional core required it. The core beam to column connections have not been made publicly available, so I don't know what basis you are using for your contention here.

My evidence that the core was not designed to stand unsupported is that it's totally bloody obvious. The building was designed to be built as an interconnected structure. My evidence that the core didn't stand when unsupported by the floors is that it didn't. Since that's all I claimed, I don;t see the problem.

Dave

[Dave Rogers]

The velocity of the upper blocks in each of these Verinage demolitions has been measured and there is a definitive deceleration and velocity loss when the upper block impacts the lower block. The deceleration causes an amplified load and that is the only way to overcome the reserve strength of the structure below and continue the collapse naturally after using external energy devices to remove several stories.

The amplified loading is only necessary because the verinage technique has to overcome the entire resistance of the supporting structure in a single impact. It's because verinage demolitions fall without rotation of the upper block that a jolt is measurable.

In the case of WTC 1 there is no deceleration and velocity loss. The upper block just accelerates at 65 to 70% of the rate of gravity throughout the entire nine stories it could be measured. So where does the overload come from?

The overload comes from the fact that the different supports at a given level fail sequentially rather than simultaneously. Whatever limited group of supports is resisting collapse at any one time is not strong enough to cause a net deceleration, and by the time other supports come into play the original set have already fractured. This is an inevitable geometric consequence of the upper block rotating as the collapse is initiated.

Dave

[Dave Rogers]

I do not deny that the upper section of the building tilted. The argument is about when it tilted. The video evidence shows the tilt occurred after the upper block had vertically descended several stories.

No, it doesn't.

http://forums.randi.org/imagehosting/thum_147644ac9bc9ba5dd1.jpg (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=17748)

Dave

[Dave Rogers]

About one thing I am very suprised.
People, engineers debate about calculations, give facts about structural desing and in same time nobady has structual drawings or they arent published (why???).

http://tinyurl.com/yjr3dds

Dave

[Tony Szamboti]

http://tinyurl.com/yjr3dds

Dave

Do you actually think the architectural drawings are the same as structural drawings Dave?

[Tony Szamboti]

No, it doesn't.

http://forums.randi.org/imagehosting/thum_147644ac9bc9ba5dd1.jpg (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=17748)

Dave

You don't have the resolution on this video to discern whether or not the roof tilted at onset, or if it dropped vertically for two to three stories and then tilted.

[Tony Szamboti]

The amplified loading is only necessary because the verinage technique has to overcome the entire resistance of the supporting structure in a single impact. It's because verinage demolitions fall without rotation of the upper block that a jolt is measurable.



The overload comes from the fact that the different supports at a given level fail sequentially rather than simultaneously. Whatever limited group of supports is resisting collapse at any one time is not strong enough to cause a net deceleration, and by the time other supports come into play the original set have already fractured. This is an inevitable geometric consequence of the upper block rotating as the collapse is initiated.

Dave

The energy dissipation for deforming and buckling a certain number of columns is the same whether it is done all at once or over a short time interval in a staggered way. That energy dissipation reduces the kinetic energy and causes velocity loss period. It isn't about trying to see the jolt. It is about the measurement of velocity loss which would be required.

There simply is no velocity loss observed in the drop of the upper section of WTC 1 commensurate with the energy dissipation which would be required to deform and buckle the columns. Something else was removing 90% of the strength of those columns.

Even if all of the columns magically missed you still can't make a case for a natural 65 to 70% acceleration of the upper section as the floors alone would have required significantly more energy dissipation to go through, tilt or no tilt.

[Tony Szamboti]

At least you don't dispute that the floors couldn't take the weight. The rotation of the other block - which, if you recall, I showed had already reached about 2º before the roofline had dropped by more than a quarter of a storey - would smear out the effect of a column-on-floor impact just as much as the effect of a column-on-column impact, and for the same reason: once the block is rotated, the columns strike the floor sequentially rather than simultaneously. I would go over the effect of vector addition of forces and the result that there is at no time a deceleration of the upper block, but Tony's repeatedly demonstrated his inability to follow this argument.



My evidence that the core was not designed to stand unsupported is that it's totally bloody obvious. The building was designed to be built as an interconnected structure. My evidence that the core didn't stand when unsupported by the floors is that it didn't. Since that's all I claimed, I don;t see the problem.

Dave

It is not obvious at all that the core required support from the floors outside of the core, and your inability to show that they did makes what you said earlier an unsupported assertion. It is extremely unlikely that the core columns required bracing from the floors OUTSIDE of the core.

[Dave Rogers]

You don't have the resolution on this video to discern whether or not the roof tilted at onset, or if it dropped vertically for two to three stories and then tilted.

Yes, I do. It's rotated by about two degrees, which equates to a two pixel shift of the top edge of the right hand side. I'd estimate the error bar as ±1º, indicating that there is a real rotation. The drop at this point is 1 pixel, where 4.5 pixels is approximately one storey; assigning an error bar of ±1 pixel I conclude that the building has fallen by less than half a storey at a time when the upper block has rotated by more than one degree.

Dave

[Dave Rogers]

The energy dissipation for deforming and buckling a certain number of columns is the same whether it is done all at once or over a short time interval in a staggered way. That energy dissipation reduces the kinetic energy and causes velocity loss period.

It seems to me that you're incapable of understanding why this is wrong. I'll try yet again. The upper block is gaining velocity due to gravitational acceleration. If, over a period of time, it gains more velocity than it loses, then there is no net velocity loss. Therefore, any jolt of less than 1G will not result in a velocity loss. I've calculated the jolt and found that, as soon as the tilt reaches more than about half a degree, the jolt never exceeds 1G, so there is never a velocity loss.

I really don't understand why someone as apparently intelligent and educated as you remains unable to do this absolutely basic piece of vector arithmetic.

Dave

[Dave Rogers]

It is not obvious at all that the core required support from the floors outside of the core, and your inability to show that they did makes what you said earlier an unsupported assertion. It is extremely unlikely that the core columns required bracing from the floors OUTSIDE of the core.

Go back and read the post you first replied to. I didn't say the core wasn't capable of standing unsupported. I said it wasn't designed to, and that it didn't. Neither of these statements is open to rational refutation.

Dave

[Dave Rogers]

Do you actually think the architectural drawings are the same as structural drawings Dave?

Jim Hoffman seems to.

Dave

[funk de fino]

You don't have the resolution on this video to discern whether or not the roof tilted at onset, or if it dropped vertically for two to three stories and then tilted.

Yet, its OK to look for a missing jolt on videos such as this??

Holy Guacemole Batman!!

The BBC does indeed have video at hi res and its shows what you say it doesnt.

[twinstead]

Holy Guacemole Batman!!



You've made my decision for me. It's Mexican food for lunch!

[Newtons Bit]

About one thing I am very suprised.
People, engineers debate about calculations, give facts about structural desing and in same time nobady has structual drawings or they arent published (why???). I really have hard time to check these claims:

1) Core isnt braced at all. I think this is a law in structural desgin that at least lift
shaft should be braced aginst horizontal loads.

The architectural SHAFT WALL is braced by the floors.

2) The only thing that gives side lateral support to core columns are trusses. Thats unbelieveble.

No. The perimeter columns are a MOMENT FRAME. They provide lateral support to the entire building. This lateral support is connected by the floors to all vertical elements.

3) The only construction that takes horizontal loads are facede column construction. Dont know how the force manages to get from ( from facede wich the winds blows) to facedes (stiffness diafragms) who are parralllel to force vector.

That would be the diaphragm (the floor). Think of it as a super deep beam.

[Mangoose]

You don't have the resolution on this video to discern whether or not the roof tilted at onset, or if it dropped vertically for two to three stories and then tilted.

How many times do I have to keep posting this?

http://img405.imageshack.us/img405/2857/aniv.gif

You can absolutely see the rotation prior to any collapse of floors on the North Face. Notice that this is at full resolution compared to the reduced image that Dave posted.

[BasqueArch]

How many times do I have to keep posting this?

http://img405.imageshack.us/img405/2857/aniv.gif

You can absolutely see the rotation prior to any collapse of floors on the North Face. Notice that this is at full resolution compared to the reduced image that Dave posted.


Too many will not be enough.
You can lead a Falser to facts but you can't make him think.

[GlennB]

You can absolutely see the rotation prior to any collapse of floors on the North Face.

Yes, you can. It cannot be denied, but I fear it will be denied.

I was going to ask Szamboti (again) about why the exterior columns bowed long before his precious CD would have ripped them inwards in a jiffy, but I suspect it's pointless.
It's kind of strange to lump Szamboti in with Heiwa and Bill Smith in the 'hopeless case' category, as he actually seems quite bright. I suppose it's just a very superficial impression.

[Hokulele]

There is a difference between educated and bright.

[BasqueArch]

The energy dissipation for deforming and buckling a certain number of columns is the same whether it is done all at once or over a short time interval in a staggered way. That energy dissipation reduces the kinetic energy and causes velocity loss period. It isn't about trying to see the jolt. It is about the measurement of velocity loss which would be required.

There simply is no velocity loss observed in the drop of the upper section of WTC 1 commensurate with the energy dissipation which would be required to deform and buckle the columns. Something else was removing 90% of the strength of those columns.

Even if all of the columns magically missed you still can't make a case for a natural 65 to 70% acceleration of the upper section as the floors alone would have required significantly more energy dissipation to go through, tilt or no tilt.

Szamboti-O-Matic
Automated Reply System

*chirp*

*!* Hello. You've selected [ Wrong #2 ] [Wrong #4 ] *!*

*!* We're Sorry - Still Wrong.
Please select correct post below and try again. *!*

---------------------------------------------------------------------------------------------------------
Wrong #1 Szamboti repeatedly missrepresents NIST floor loading.[P#204]

Wrong #2 Szamboti claims collapsing columns fell axially atop each other. [P#204]

Wrong #3 Szamboti claims central core fully braced within itself, no floor bracing.[P#204]

Wrong #4 Szamboti claims "missing jolt" = CD.[P#204] [P#182]

Wrong #5 Szamboti claims WTC1 fell several stories and then tilted.[P#204] [P#148]

[P#205] [ http://www.youtube.com/watch?v=YHCeRYreMp8 ]


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You can lead a Falser to facts but you can't make him think.

[Mangoose]

Here is another video showing the tilt prior to any collapse on the North Face. It is the only video showing the South Face at collapse initiation:

http://img382.imageshack.us/img382/8177/asas.gif

Despite the poor quality, the upper block (look especially at the antenna mast) can be seen tilting to the right, and notice that this is prior to the collapse of floors on the West Face that occurred at the same time as floor failure on the North Face. But here we can see what is going on at the area where bowing columns and intense fire were photographed six minutes earlier:

http://img65.imageshack.us/img65/3134/12451161.jpg

The fires on Floors 97 to 101 are seen in the video as intensifying, possibly exiting the building (similar to the fires on the North Face exiting the building during the collapse on the North Face). This, along with the tilt in the direction towards this area, suggests that the floors below the fires (the ones with inward bowing columns, Floors 95-98) collapsed first. And this is indicated as well by the appearance of a dust cloud on the southeast edge of the building directly below the fires in the above video.

[Scott_Milner]

I'm glad to have missed this display of nonsense during my brief absence over the weekend. The very columns you [anyone supporting the official story] say that melted due to heat, were strong enough to prevent the upper section from 'crushing' the core, and caused tilting instead.

The core columns, and perimeter columns were connected and could not have caused a rotation as there was no force exerted in that direction. Your theories based on Bazant's model do not make any scientific sense. The video evidence shows the upper block smashing apart before the tower beneath the impact hole begins to descend. I feel sorry for Mr. Szamboti having to hold hands through this lecture.

[Hokulele]

Melted?

[TruthersLie]

I'm glad to have missed this display of nonsense during my brief absence over the weekend. The very columns you [anyone supporting the official story] say that melted due to heat, were strong enough to prevent the upper section from 'crushing' the core, and caused tilting instead.

The core columns, and perimeter columns were connected and could not have caused a rotation as there was no force exerted in that direction. Your theories based on Bazant's model do not make any scientific sense. The video evidence shows the upper block smashing apart before the tower beneath the impact hole begins to descend. I feel sorry for Mr. Szamboti having to hold hands through this lecture.

melted?

umm who claimed any of the columns melted?

damn.... reading for comprehension is your friend... you should try it.

[Dave Rogers]

I'm glad to have missed this display of nonsense during my brief absence over the weekend. The very columns you [anyone supporting the official story] say that melted due to heat,

You know, if you start your argument with a blatant lie, it's unlikely to get you any positive attention from the other side of the debate.

were strong enough to prevent the upper section from 'crushing' the core, and caused tilting instead.

And if you continue by such a blatant misrepresentation of the other side's argument - to the extent that, nobody having said anything remotely similar to this, you're simply making things up and pretending somebody else said them - then it won't make things any better.

The core columns, and perimeter columns were connected and could not have caused a rotation as there was no force exerted in that direction.

Now this is simple scientific illiteracy. What direction do you imagine a force has to be exerted in, to cause a rotation?

I suggest, as a starting point, that you read the Wikipedia article on torque. It may help you a little. Now, we know that the forces on the upper block were gravity (down) and compressive forces in the support columns (up). When one side of the structure became overloaded, the support columns on that side failed and were no longer able to exert an upward force. However, the columns on the other side were still able to exert an upward force, so the resultant upward force was applied off-centre to the upper block. Since the downward force due to gravity was still applied through the centre of mass of the block, a torque was applied to the upper block about a horizontal axis. When this torque became sufficiently great, the upper block began to rotate. This could not occur without the remaining supports failing, so they too failed, at which point the upper block began to fall.

Since the only forces involved here were gravity and the structural resistance of the lower columns, would you like to explain which of those you believe didn't exist?

Your theories based on Bazant's model do not make any scientific sense.

:i:


The video evidence shows the upper block smashing apart before the tower beneath the impact hole begins to descend.

The video evidence shows the upper block rotating before it starts to fall. This has been demonstrated so many times in this thread that it's beyond a joke. It's clear that there is some damage to the upper block simultaneously with that to the lower, but the clouds of debris obscure the fine details so thoroughly that anybody making as definite a proclamation as yours is either delusional or lying.

I feel sorry for Mr. Szamboti having to hold hands through this lecture.

I feel sorry for Tony, but not for the same reason.

Dave

[Tony Szamboti]

Now this is simple scientific illiteracy. What direction do you imagine a force has to be exerted in, to cause a rotation?

I suggest, as a starting point, that you read the Wikipedia article on torque. It may help you a little. Now, we know that the forces on the upper block were gravity (down) and compressive forces in the support columns (up). When one side of the structure became overloaded, the support columns on that side failed and were no longer able to exert an upward force. However, the columns on the other side were still able to exert an upward force, so the resultant upward force was applied off-centre to the upper block. Since the downward force due to gravity was still applied through the centre of mass of the block, a torque was applied to the upper block about a horizontal axis. When this torque became sufficiently great, the upper block began to rotate. This could not occur without the remaining supports failing, so they too failed, at which point the upper block began to fall.

Since the only forces involved here were gravity and the structural resistance of the lower columns, would you like to explain which of those you believe didn't exist?

The video evidence shows the upper block rotating before it starts to fall. This has been demonstrated so many times in this thread that it's beyond a joke. It's clear that there is some damage to the upper block simultaneously with that to the lower, but the clouds of debris obscure the fine details so thoroughly that anybody making as definite a proclamation as yours is either delusional or lying.

Removing one wall from a four sided structure will not cause rotation. It is actually the walls which are normal to the overloaded or failed wall which would resist the torque in the direction of that wall. In the case of the North Tower it would have been the east and west walls resisting torque towards the buckled south wall.

The NIST calculations for load increases on the east and west walls, due to hat truss redistribution from both the impact on the north wall and buckling of the south wall, show it was no more than 50% while they were capable of handling 500% of the original load on them. It is just one big hand wave that the instability of the south wall then spread to the east and west walls. It is not supported by any analysis. In fact the analysis shows they should not have failed and allowed any rotation.

[funk de fino]

Give it up Tony, you have been shown to be a charlatan many times over in this thread.

It really is quite sad. Although not as sad as your lies about Silverstein and the documentary.

[newton3376]

I'm glad to have missed this display of nonsense during my brief absence over the weekend. The very columns you [anyone supporting the official story] say that melted due to heat, were strong enough to prevent the upper section from 'crushing' the core, and caused tilting instead.

Who says that any columns melted?

So you do believe there was "tilting"?

The core columns, and perimeter columns were connected and could not have caused a rotation as there was no force exerted in that direction. Your theories based on Bazant's model do not make any scientific sense. The video evidence shows the upper block smashing apart before the tower beneath the impact hole begins to descend. I feel sorry for Mr. Szamboti having to hold hands through this lecture.

I'm confused.....

#1. What does "core columns and perimeter columns were connected and could not have caused a rotation" mean exactly? How do the columns "cause" a rotation?

#2. So you are saying there is no "rotation" but there is "tilting".....what exactly is "tilting" and how is it different from "rotation"?

I will likely regret saying this but......could you please clarify the terms you are using? It makes it so much easier to piece together the puzzle of idiocy you are building....

[Grizzly Bear]

It is just one big hand wave that the instability of the south wall then spread to the east and west walls. It is not supported by any analysis. In fact the analysis shows they should not have failed and allowed any rotation.

The visual documentation is incontrovertible and I've used the south tower to model it because it's collapse mechanism is similar:
http://img22.imageshack.us/img22/5246/studyg.jpg

The "pretty picture" as you so referred to it as shows this. The graphics on the left side show the deflection of three of the columns on that face and they're labeled as references to the picture. See this TS? This is what happens when an off axis load causes a series of columns to fail. Both towers exhibited the same behavior pre-collapse, and with the collapse mechanisms being nearly identical in nature the south tower provides for us a rather nice model for the north tower. You know... about the buckling you say didn't happen...

And I don't believe in using card board boxes to model a macroscopic structure, Gage tried it and demonstrated spectacularly why the model you're suggesting fails.