What is Crushing This Tower?

reply to post by GenRadek

The floors proceeded to pancake afterward.

If memory serves that was an early opinion that was soon discarded in favor of the Bazant crush down hypothesis, that is the story that NOVA ran with, but even by that time it had been chucked.

There was no pancaking because there were no pancaked floors. The fdnyphoto that you guys bandy about cannot be from the base of the tower because you can see the slurry wall right there with your own eyes.

Here you go posted before but you obviously missed that www.stevespak.com... Second and third pictures down with description!!!! Check out last pic at bottom of page.

Then the description is wrong.

You can see the slurry wall, I can see the slurry wall. The south tower was not adjacent to the slurry wall.

WTC6 was though if that is any help, looking at the url.

You can't use the picture and then ignore what is in the picture.

reply to post by Darkwing01

If memory serves that was an early opinion that was soon discarded in favor of the Bazant crush down hypothesis, that is the story that NOVA ran with, but even by that time it had been chucked.

There was no pancaking because there were no pancaked floors. The fdnyphoto that you guys bandy about cannot be from the base of the tower because you can see the slurry wall right there with your own eyes.

Ok this ignorance is really starting to get on my nerves.

Nova and the early hypothesis was based on a progressive pancaking of the floors as the INITIATOR of the total collapse of the WTC. However, after further study and review of the collapse and what started the collapse, it was seen that it was actually the exterior columns bending INWARD prior to collapse. Once the exterior columns failed, the building began its descent. The floors pancaked, because as workers were clearing up the site, they were cutting through stacks of floors compressed and described as "Geologic" formations of layers. This is the evidence of pancaked floors, including the pictures of the pancaked floors. Also the caption of that one picture of the pancaked floors has it as found in WTC2s footprint area.

Originally posted by Seventh

There were explosions?...source.

I don't have one. I don't think there were any. Some loud bangs maybe.

I'm just wondering what the squibs were.

reply to post by Darkwing01


You say the slurrywall wasnt near the south tower look at this then!!



Here is another just to double check



Well saying that the Fire Dept would post wrong info is pretty low considering what happened to them that day!!

reply to post by wmd_2008

You have a reading problem at what point did I say I was a steel salesman?

Based on the rest of your post and your previous posts there is lolz irony in you claiming I have a reading problem. How many times in my previous post did I attempt to drill in the same point, only to have it go flying straight over your head every time?

And a steel company representative is basically a glorified steel salesman. Though I can understand you want to think of yourself as having a slightly more technical role, I've dealt with reps from suppliers before so you can't pull the wool over my eyes.

There is a deceleration as the falling mass impacts everyfloor on the way down very very small the only thing that resist the downward force is the floor connections YOU know the bit that holds the floor up but as soon as the impact force exceeds the strength of the connection the connection will break

A little grammar would make your post more decipherable (tip for free).

So you are claiming the deceleration at each floor impact was "very very small". Interesting. The only way the floor connections could provide this "very very small" deceleration is if they provided an upwards force only very, very slightly greater than the force they provided when the tower was at rest. Seems a bit fishy, especially considering that they were no way at their capacity when the tower was at rest and have substantial safety factor designed in. Perhaps they were weakened to achieve this?

What about the columns between floors? Are you claiming that a group of columns would not provide an upwards force to a stack of concrete floors impacting them? I don't think that sounds very correct..

that floor then joins the falling mass which although traveling slightly slower now has a far greater mass and the process repeats!!!

I'm not sure what the use of triple exclamation marks is supposed to be emphasizing. Conservation of momentum does absolutely nothing to help the towers collapse so surely you are not excited about that?

So do you want to explain to every one why the video of the rice bag shows a higher load when fall than at rest ?

Certainly. As I made quite clear to those without reading difficulties in my previous posts, the bag of rice shows a higher load because the scales provide an average upwards force greater than the stationary weight of the bag. You will also notice that this force has caused the bag to decelerate and come to rest. As I keep pointing out, this analogy is useless and irrelevant because the falling top sections of the towers did not undergo an average deceleration once they met undamaged lower structure, they maintained an average acceleration. Therefore a better analogy would be to use a skydiver not yet at terminal velocity. The air he is falling through provides resistance such that he is not quite accelerating at 100% free fall, but not enough that it cancels out his downwards acceleration due to gravity (this will occur once he is at terminal velocity).

OHTHATS RIGHT YOU WONT BECAUSE IT SHOWS YOU ARE WRONG!

BOOM! AND WHAT?

The scales show the increase IN LOAD THATS THE WHOLE POINT!!!!

That's who's whole point? I thought you were trying to debunk my claim that the top section of a tower crushed the lower structure with an average force of only about 1/3rd its stationary weight? Ignoring all the points I make and attempt to make painfully clear and instead going off on these tangents is proving nothing. Once more: The scales provide an average upwards force great enough to cause an average deceleration in the mass. The lower structure of towers provided an average upwards force small enough to allow the top section to continue an average downwards acceleration due to gravity of about 2/3rds free fall. Get it yet? It's taken a few posts.

By the way the example of the 50lb is a good example YOU would be the floors below impact the mass falling would be the top floors and you would be crushed if you kept your arms rigid. IF that would not be the case film it or prove it using your best physics after all the link I gave was to a physics site or are you claiming they are wrong!!

If you have a problem with any of the points I made showing how you are irrelevant and incorrect in your falling weight analogy please address them specifically. Don't just reassert that it is indeed a good example.


Here's hoping for a reply that actually attempts to address the points I am making.

reply to post by DrinkYourDrug


The whole OSer argument here hinges on an incorrect understanding of dynamic loading, and the towers ability to hold its own weight by at least x2 (factor of safety for components used in tall buildings is at least x2, and we know that a combination of these components joined together increases the weight handling ability).

They fail, or refuse, to address equal opposite reaction laws. They think momentum conservation means an object moving will not stop regardless of friction/resistance.

One poster thinks PSF mean weight, and doesn't even realise that loading is expressed in pressure, calculated from weight. He also thinks we're not talking about mechanics.

Another one thinks there are no impossible physics, and that the laws of motion are not the complete physics, and we're ignoring Pe and Ke.

Let alone those who think that sagging trusses can put a pulling force on, and snap, columns, and on top of that they were inches away from weak points that were not effected.

They claim to be many things, electrical engineer claims one, but they can't answer simple physics questions when asked. They have obvioulsy had no experience working in any kind of mechanical field. Selling steel is not working in a mechanical field. All they do is keep the discussion going around in circles, but they don't realise that with this constant repeating of facts and truth, more people read the truth. If they stopped with their nonsense then the discussion would stop.

So to the OSers, thank you keep up the good work lads!!!

Originally posted by DrinkYourDrug

So you are claiming the deceleration at each floor impact was "very very small". Interesting. The only way the floor connections could provide this "very very small" deceleration is if they provided an upwards force only very, very slightly greater than the force they provided when the tower was at rest. Seems a bit fishy, especially considering that they were no way at their capacity when the tower was at rest and have substantial safety factor designed in. Perhaps they were weakened to achieve this?

What about the columns between floors? Are you claiming that a group of columns would not provide an upwards force to a stack of concrete floors impacting them? I don't think that sounds very correct..

There were no columns between the floors. That was the point of having a "tube-in-tube" construction with light steel truss supports as floors. No internal columns to take up valuable space. All vertical columns were relegated to the exterior and interior tube. When the top section began its collapse, all it was impacting was the floor below it. The only resistance of that floor hinged on its truss seat connections that were welded onto the columns. That was it.

reply to post by ANOK


So once again the common misconception that "equal opposite reaction laws" some how are suppose to stop the collapse from happening. Isnt Newton saying that For every FORCE applied, there must be an equal FORCE in the opposite direction? When you push on something, it pushes back upon you equally, even if it does not move. Easy to understand.

Ok, so If I push on a car, the car pushes back on me. According to your version of Newtons laws, I shouldnt be able to push the car and put it in motion at all, since A) It is much heavier than I am, and B) it has more mass than I do. However, in neutral, I can start pushing the car itself and get it moving. How can I be moving the car, if it is pushing equally back on me ANOK? The car weighs a hell of a lot more than me, and has a lot more mass, and yet, I can push on the car, get it in motion, and then continue pushing the car down the street, even gathering speed or keeping a constant speed. In effect, I just broke (your version of the) Laws of Physics!!

reply to post by GenRadek

When the top section began its collapse, all it was impacting was the floor below it.

That's a very idealized and optimistic view to take and would apply if the top section did not lean over at all and remained perfectly aligned to slot its floor sections between the lower section's columns (while all the top section columns also miss the bottom section columns). How would this enable large structural members to be ejected at high velocity out the sides of the towers?

If it was just floors failing floors we would have seen columns sticking high above the collapse wave (like the "spire") and failing by toppling over once their unrestrained length became too long to support their own weight (unlike the "spire"). The columns were destroyed by something during collapse, but it wasn't bending under their own weight over a long unrestrained length.

reply to post by turbofan

What is Crushing This Tower?

Not a smaller upper block, that's for sure. Bazants paper is wrong and has been debunked by quite a few papers:

The Missing Jolt:
A Simple Refutation of the NIST-Bazant Collapse Hypothesis

Destruction of the World Trade Center North

Momentum Transfer Analysis of the Collapse of the Upper Storeys of WTC 1

And this one.

Originally posted by DrinkYourDrug
If it was just floors failing floors we would have seen columns sticking high above the collapse wave (like the "spire") and failing by toppling over once their unrestrained length became too long to support their own weight (unlike the "spire").

There are several video clips that show this, for example this clip at 9 seconds at the left:

www.youtube.com...

or this one at 36 seconds at the right:

www.youtube.com...

reply to post by -PLB-

There are several video clips that show this, for example this clip at 9 seconds at the left:

Not sure I see this one. Towards the left side of the building?

or this one at 36 seconds at the right:

I see this one, thanks, it is interesting. Close inspection reveals that the top of this piece of column lines up with about the top of the initiation zone. The best explanation I can think of (in the context of a pancaking floor collapse) is that its failure was caused by a combination of it having to take the loads usually carried by severed neighboring columns and its unrestrained length increasing as a result of the floors falling away from it (any other suggestions?). The problem with this theory is the position of the failure. The column appears to be severed at the very top of the initiation zone. If an increasing unrestrained length was responsible for its failure I would expect failure to occur at its weakest point - halfway between its unrestrained length and at maximum distance from the remaining upper and lower floors which restrain it.

It also did not topple over as it became increasingly long but was pulled downwards out of camera shot. IMO the glimpses of remaining columns are the exception not the rule, especially when considering the total number of internal and external columns.

reply to post by DrinkYourDrug


In the first clip it is not a single column, but a large segment (nearly the whole side) that topples over. And indeed, it isn't perfect toppling that happens, but I'd say that is to be expected, as there is a huge chaotic mass below destroying everything in its path. To me it is no surprise that this mass also destroys the columns that are still standing in the second clip but at a lower position.

Anyway, the problem is that we do not have a reference. How can any of us know what a natural progressive collapse of that building should look like? I sure don't. I can only imagine it, and then I do not really see something that is in conflict. On the other hand, I don't see anything that proves explosives.

I think the main truther argument is that a progressive collapse without explosives isn't possible at all, and not so much that it doesn't look like it.

reply to post by -PLB-


I think the main conclusion is that it is difficult to determine how much resistance either the core or outer columns could be expected to offer during a progressive collapse. I still maintain that they must have offered some inter-floor resistance, else there would be just a few big pieces of column sections left over. Instead (unless I'm mistaken) most of the columns were extensively destroyed which would have taken a significant amount of energy.

My point is, the columns must have been capable of offering some inter-floor resistance which makes maintaining an average ~2/3rds free-fall an all the more incredible feat.

Originally posted by DrinkYourDrug
I think the main conclusion is that it is difficult to determine how much resistance either the core or outer columns could be expected to offer during a progressive collapse.

I agree.

I still maintain that they must have offered some inter-floor resistance, else there would be just a few big pieces of column sections left over. Instead (unless I'm mistaken) most of the columns were extensively destroyed which would have taken a significant amount of energy.

My point is, the columns must have been capable of offering some inter-floor resistance which makes maintaining an average ~2/3rds free-fall an all the more incredible feat.

I don't think that many columns were "destroyed". When I look at images of ground zero, I see many columns with little damage that are broken exactly at the place they were attached to the next column. It doesn't seem to me that it required much energy to break a columns at its weakest point. Besides that, Bazant made an estimate how much energy it would take if all columns did bend, and his conclusion was that it was about 8 times less than the available kinetic energy at the first intact floor that was destroyed. So I do not see the amount of energy that is lost in destroying a floor as a big issue.

reply to post by ANOK


Havens you ever heard of industrial origami you idiot?

Lol jokes,, but that's an awesome point I hadn't thought of until you mentioned. Just how the he'll did it all fit in there?

reply to post by DrinkYourDrug


Wait,, so the only way to decel a falling object is to provide an upward force?

I want to quote south park-"are you high, or just incredibly stupid?"

So if I dropped a cannonball onto a thin sheet of plywood, the cannon ball would crash through the plywood and not slow down at all?


Lol,,, everybody runnnn, were arguing 2 year olds who still haven't figured our how newtonian matter and physics behave. But to give them credit, 2 year olds don't have a fully formed and functioning brain yet.

reply to post by VonDoomen

Wait,, so the only way to decel a falling object is to provide an upward force?

Yes.

I want to quote south park-"are you high, or just incredibly stupid?"

I'm honestly not sure if this is sarcasm because of the highly obvious point above or ridicule because a surprising number of people will vehemently argue against the top section only applying an average crushing force of ~1/3rd its stationary weight.

By the way, not everyone loses all their mental capacities when under the influence of whatever substance.

So if I dropped a cannonball onto a thin sheet of plywood, the cannon ball would crash through the plywood and not slow down at all?

It would likely slow but how thin is thin?

Lol,,, everybody runnnn, were arguing 2 year olds who still haven't figured our how newtonian matter and physics behave. But to give them credit, 2 year olds don't have a fully formed and functioning brain yet.

Really have no idea what this is on about or who this is directed at.