NIST Admits Total Collapse Of Twin Towers Unexplainable

reply to post by cams


Two isolated pockets of fire on the 78th floor. OK. 78th floor has been shown time and time again to be a mechanical floor. Not a awful lot to burn there. 2 pockets of fire on that floor. So what... What about the 10 or more floors above that one. I have watched the videos time and time again. Those fires on the floors above were out of control. You can even watch on one of the videos how the smoke is pulled BACK into the building. Those fires were big enough to "create" their own "weather" around them. A whole lot of air flowing back into the structure feeding the fires. Two isolated pockets of fire on one floor proves nothing.

Edit to add:

Your math doesnt even work out here. If free fall in a vacuum is 9.2 seconds..and the first tower fell in 9 seconds. Hmmmmmm..something does not add up. Valhal did some figures (btw shes a engineer) that showed that they did not fall at free fall speeds. It took longer to fall than 10 sec.

[edit on 17-10-2007 by six]

Originally posted by seanm
Indeed. Someone with your claimed background who is unable to calculate the kinetic energy of two masses, one 40,000 tons, the other 110,000 tons, falling 6 feet onto a structure

Wrong! You DO NOT have two bodies, you have one rigid body undergoing deformations (all of the columns and members were bolted/welded, why do you think this is done?), and you DO NOT have ANY free-fall distance.

If you want to talk about the way the floors could theoretically collapse, go ahead, but floors don't hold buildings up, and this is the kind of thing that should have you thinking twice before second-guessing someone who's been through statics and strengths of materials and everything else that a degreed civil engineer such as Griff goes through. Dynamic loads are calculated as forces that vary in time (very short times), and just because something isn't designed for dynamic loading doesn't mean anything goes when a dynamic load is present. Materials become more brittle under dynamic loading. And the yield strength that the safety factor references isn't even a point at which "anything goes". That's only the point at which the material begins to permanently deform. So you don't even necessarily have failure even when a material is exceeding simply what it's designed for, and I would say this is especially the case when bolts and etc. don't come into play, such as when you have a massive, continuously-welded column you're theoretically distributing part of a load across.


Even generalizing floor collapses, the trusses were independent of each other. So if one truss falls onto the next floor, ok, but that doesn't at all mean that its neighbors are going to do the same. Concrete has no tensile strength and it wouldn't be able to hold the trusses together, etc. But I don't expect you'll let anything realistic like that get in your way either.


PS -- This is all the stuff NIST didn't test when they say they stopped at the "initiation point" -- a name misleading in itself because they never proved what (if anything) happened next! What is it the initiation of? Further deformations? Additional local collapses? This is after they've admitted to having to ramp up the parameters to unrealistic levels, and contradicting older lab data from the UK on fires on steel frames.

[edit on 17-10-2007 by bsbray11]

Might want to check out some facts from NIST about the builidngs withstanding the impacts of the planes and should have kept on standing.

www.nist.gov...

Post-impact capabilities of the WTC towers assessed. Demand to capacity ratios—the calculations indicating whether or not structures can support the loads put on them—showed that for the floors affected by the aircraft impacts, the majority of the core and perimeter columns in both towers continued to carry their loads after the impact. The loads from damaged or severed columns were carried by nearby undamaged columns. Although the additional loads strained the load-bearing capabilities of the affected columns, the results show that the columns could have carried them. This shows that the towers withstood the initial aircraft impacts and that they would have remained standing indefinitely if not for another significant event such as the subsequent fires. NIST previously reported that the towers had significant reserve capacity after aircraft impact based on analysis of post-impact vibration data obtained from video evidence on WTC 2, the more severely damaged tower.

www.tms.org...

The early news reports noted how well the towers withstood the initial impact of the aircraft; however, when one recognizes that the buildings had more than 1,000 times the mass of the aircraft and had been designed to resist steady wind loads of 30 times the weight of the aircraft, this ability to withstand the initial impact is hardly surprising. Furthermore, since there was no significant wind on September 11, the outer perimeter columns were only stressed before the impact to around 1/3 of their 200 MPa design allowable.

[edit on 17-10-2007 by ULTIMA1]

reply to post by Black_Fox


the explanations i have read previously and seen explained on t.v. are simple enough for me to understand.these buildings had a steel outside cage type frame work holding onto each floor as the building went up--------there was no solid concrete floor to floor inner concrete wall supports-------eventually the jet fuel was burning at temperatures hot enough to melt the steel that was inadequately fireproofed --the upper floors weighing 1000'nds of tons collapsed to the next floor down---------the impact hammer effect was so powerfull that the supports to the unmelted steel to that floor and the next floors couldnt resist the foot pounds energy force imposed on them---------they had to let go------sorry but this design should never again be built------its too weak for this kind of attack.

Originally posted by yahn goodey
the explanations i have read previously and seen explained on t.v. are simple enough for me to understand.these buildings had a steel outside cage type frame work holding onto each floor as the building went up--------.

Please read the post above yours. NIST states that the builidngs wihtstood the planes impacts and should have kept standing.

Originally posted by MrKnight
The columns of each floor tranfer the load down to the next floor, thus creating the system to the foundation.

This is erroneous at best. The columns don't transfer the load to the next floor. The next floor adds it's load to the column. The column sustains the load of the entire building the entire time. Load does not go from floor-to-column-to-floor-to-column etc. to foundation. It goes from floor 110 to column. Then from floor 109 to column, thus adding the load of floor 110 and 109. Then floor 108 transfers to the column and at the 108 mark, the column carries floor 110 load + floor 109 load + floor 108 load. This extends down into the foundation. The floors are independant of each others loads.

I'm still waiting to hear how the columns collapsed from floor load that they were already designed for and then some. You nor NIST have done this sufficiantly. Sorry.

The additional load may have come from, oh I don't know a few hundred thousand pounds (around 400,000) of aircraft that slamed into the structure of three to four floors.

I'll give you this. But consider since it didn't cause a pancake at that moment, the floors where able to resist that load. Talk about factors of safety....that's 200 tons extra load that the floors were able to hold.

Taking out columns, and floor structure. Then a buring hot fire that twisted and bent remaing structure that lead to a multiple floor failure.

I could see multi floor collapses. What I still can't see and no one has yet to sufficiantly explain is the global collapse, including the columns.

Then a few hundred tons of concrete, steel and glass slamming down and weaking the floor structure and column at the next level.

I can see weakening the floor but not the column. The connections but not the column. What about the columns NIST?

And yes, most systems if subjects to the right forces will fail, hence the phrase, "system failure".

I've bolded the key words here.

Originally posted by six
reply to post by cams

 

Two isolated pockets of fire on the 78th floor. OK. 78th floor has been shown time and time again to be a mechanical floor. Not a awful lot to burn there. 2 pockets of fire on that floor. So what... What about the 10 or more floors above that one. I have watched the videos time and time again. Those fires on the floors above were out of control. You can even watch on one of the videos how the smoke is pulled BACK into the building. Those fires were big enough to "create" their own "weather" around them. A whole lot of air flowing back into the structure feeding the fires. Two isolated pockets of fire on one floor proves nothing.

Correct.

It always amazes me how 9/11 conspiracists will hold onto myths so tenaciously. The firemen who reached the 78th floor of WTC 2 reported what they saw on that floor. They never got any further up to the floors where the massive fires were burning. WTC 2 collapsed before they got there.

The 911 truth movement is going circles, chasing its tail as the rest of the World looks on and laughs. The line has been crossed and now questioning the guv's explanations for 911 gets you the same eye rolling and snickers that discussing UFO's does. There is no new evidence to be had, it was all carted away to China for pennies thanks to the hero Guliani.

These discussions seem to follow the same pattern every time. People are so desperate to find a chink in the armour that they jump on and twist things around like the title of this thread. Can we get past this and move on another avenue of investigation or discussion? Right now all we get is a mish-mash of the same stuff over and over again. Yes, buildings never fell from fire before. Yes, the trade towers were unique in design. Yes, they fell nearly 'effortlessly', even with a pretty solid inner core that seemingly pulverized on the way down. Etcetera, etcetera. There is nothing new, just circular logic on both sides and a public at large that grows more and more distant from caring about the nuts and bolts of what happened that day. Trying to push anything harder than a LIHOP agenda on the masses will get you scorn and ridicule - nothing more. At this point nothing less than Cheney holding a news conference to detail how he personally packed the C4 into the trusses while the buildings were being raised will make a difference.

Originally posted by enigmania
but I find it very hard to understand how someone with a degree in engineering,

Mr. Knight stated he worked with structural engineers, not that he is one. If I'm incorrect, please show me my error.

Originally posted by ULTIMA1
Might want to check out some facts from NIST about the builidngs withstanding the impacts of the planes and should have kept on standing.

Do you even read the quotes you cite?

Yes, the NIST report said that the buildings should have kept standing IF NOT for any other events, like the FIRES.

This is really pretty simple.

The planes took out load-bearing beams. The loads were then transferred to the remaining beams immediately after impact.

Now here is where people have different opinions.

The opinion of the most truthers is that they, based on pure speculation and faith, do not BELIEVE that the fires could have weakened the steel enough to cause a global collapse. Therefore because of this belief, they can only conclude one other alternative -explosives were used.

Other people educated in the sciences do believe that the initial damage and the fires combined to weaken the WTCs to cause the collapse.

So pulling quotes from the NIST report about the buildings withstanding the initial impacts is really getting pretty old and is totally irrelevant to the discussion. Everybody saw that they withstood the initial impact.

Originally posted by bsbray11

Originally posted by seanm
Indeed. Someone with your claimed background who is unable to calculate the kinetic energy of two masses, one 40,000 tons, the other 110,000 tons, falling 6 feet onto a structure

Wrong! You DO NOT have two bodies, you have one rigid body undergoing deformations (all of the columns and members were bolted/welded, why do you think this is done?), and you DO NOT have ANY free-fall distance.

Take a look at any video of WTC 1 and 2's collapses. The top block of WTC 1 was 40,000 tons that came down as one piece on to the rest of the building. It fell 6 feet before meeting any resistance.

The top block of WTC 2 was 110,000 tons. It pivoted on one point causing it to lean to one side before the pivot point failed and the bock started falling straight down.

Calculate the kinetic energy of each block and report back.

reply to post by bsbray11


Thanks bsbray. I had a response but you sufficiently covered it.

Originally posted by robert z
The planes took out load-bearing beams. The loads were then transferred to the remaining beams immediately after impact.

Well here is an engineering lesson for everyone. Beams are horizontal members that take a load along the length. Columns are vertical members that take a load down the center (concentric). They are 2 totally different members and are designed for totally different. I think you ment columns.

The opinion of the most truthers is that they, based on pure speculation and faith, do not BELIEVE that the fires could have weakened the steel enough to cause a global collapse. Therefore because of this belief, they can only conclude one other alternative -explosives were used.

Actually, it's based on more than speculation and faith. It's based on years of studies pre-9/11 of structural fires and how they perform. It's based on NIST's own structural models that wouldn't collapse...even when exposed to fires hotter than jet fuel. Etc. etc.

Originally posted by seanm
The top block of WTC 2 was 110,000 tons. It pivoted on one point causing it to lean to one side before the pivot point failed and the bock started falling straight down.

Calculate the kinetic energy of each block and report back.

Hmm... the top block pivoted but also fell freefall? How is that possible? Calculate yourself out of that hole please.

reply to post by sp00n1


As i predicted, the debunkers totally glossed over the fact that NIST's physical models failed to fail. It doesn't take a psychic to figure this one out...

Apparently they can't deal with the fact that it proves all of NIST's theories are total trash.

Why is it that under conditions far worse than on 9/11, the physical models still stood up without any localized collapse or significant deformation of the truss beams?

Perhaps Allah really was on the side on the terrorists, because i dont know who else could negate the laws of physics.



[edit on 10/17/2007 by sp00n1]

Originally posted by robert z
The planes took out load-bearing beams. The loads were then transferred to the remaining beams immediately after impact.


So pulling quotes from the NIST report about the buildings withstanding the initial impacts is really getting pretty old and is totally irrelevant to the discussion. Everybody saw that they withstood the initial impact.

Oh i have a lot more then just quotes. I have pages of evidence. Something you seem unable or unwilling to post.

1. According to the Purdue animation the plane's aluminum airframe was shreded by the steel as soon as it hit the building. Also the plane that hit the south tower went in at an angle through the side of the building, not causing much damage to the core.

2. We have lots of evidence that the fires were not big enough or burn long enough to cause the steel to weaken.

A. Firemen who made it tie 78th floor of the south tower reported only small isolated fires, not the big inferno of the official story.
www.firehouse.com...

Battalion Seven: "Ladder 15, we've got two isolated pockets of fire. We should be able to knock it down with two lines. Radio that, Radio that, 78th floor numerous 10-45 Code Ones"

B. None of the firechiefs on scene beleived the towers would collaspe. They were only worried about the upper floors above the fires collapsing if the fires would have burned for several more hours, (which they didn't)

9/11 Commission report, staff statement 13, page 20

None of the chiefs present believed a total collapse of either tower was possible. Later, after the Mayor had left, one senior chief present did articulate his concern that upper floors could begin to collapse in a few hours, and so he said that firefighters thus should not ascend above floors in the sixties.

C. Photos and videos show the fires burning out well before the towers collasped, no flames showing out the widows that you would have with a big inferno.

Photos of no flames comming out windows.
i114.photobucket.com...

i114.photobucket.com...

i114.photobucket.com...

i114.photobucket.com...

i114.photobucket.com...

i114.photobucket.com...

www.pleasanthillsfire.org...

Fires Have Never Caused Skyscrapers to Collapse

Excepting the three 9-11 collapses, no fire, however severe, has ever caused a steel framed high-rise building to collapse. Following are examples of high-rise fires that were far more severe than those in WTC 1 and 2, and Building 7. In these precedents, the fires consumed multiple floors, produced extensive window breakage, exhibited large areas of emergent flames, and went on for several hours. The fires in the WTC towers did none of these things.

[edit on 17-10-2007 by ULTIMA1]

reply to post by ULTIMA1


Again with the isolated pockets of fire on a mechanical floor. Nothing is going to burn on the mechanical floor. Look at the floors above 78. Big fires...Huge fires...Fires big enough to create wind that flowed BACK into the building.The evidence is right there in the video.

Originally posted by sp00n1

As i predicted, the debunkers totally glossed over the fact that NIST's physical models failed to fail. It doesn't take a psychic to figure this one out...

I would guess that if the physical models showed a collapse you would be the first to say that it is impossible to model the actual WTC buildings.

This is why I put little stock in the physical models. Trying to re-create the actual buildings and damage is a bit of a stretch.

Originally posted by six
Again with the isolated pockets of fire on a mechanical floor. Nothing is going to burn on the mechanical floor. Look at the floors above 78. Big fires...Huge fires...Fires big enough to create wind that flowed BACK into the building.The evidence is right there in the video.

But where is all the burning jet fuel that we were told was supposed to be running down through the floors and becomming a big inferno by the official story?

Where is the big inferno that is supposed to be weakening all that steel ?

[edit on 17-10-2007 by ULTIMA1]

I hesistate to post this because the source is an anonymous NIST whistleblower not identified.

However this is a conspiracy site...take it for what it is worth.

I hope the gentleman comes forward some day!

Here is the link

an excerpt

"When I first heard of [9/11 truth] and how the NIST "scientists" involved in 911 seemed to act in very un-scientific ways, it was not at all surprising to me. By 2001, everyone in NIST leadership had been trained to pay close heed to political pressures. There was no chance that NIST people "investigating" the 911 situation could have been acting in the true spirit of scientific independence, nor could they have operated at all without careful consideration of political impact. Everything that came from the hired guns was by then routinely filtered through the front office, and assessed for political implications before release."