If you are looking for precedents, how many high-rise buildings have suffered such damage and then been exposed to fires? The WTC attacks were unprecedented, so it is hardly fair for you to ask me for comparable events. I am an engineer, I was not surprised on the day when the towers collapsed, I have since read the detailed analysis from the engineers who conducted the investigation and I do not see any evidence from the "truth" movement that would make me doubt the official story. You are the one who is claiming that all the engineers who have studied the collapses in detail are wrong, so it is up to you to provide calculations to back up your opinions.

http://www.youtube.com/watch?v=PFb2U8C0gBY...st495368%2Ehtml

German hip hop about 9/11

All of those tables and the weightlifter are very good Pericynthion; I can agree with all of your theory. I would very much like to know how this all relates in anyway whatsoever to WTC7 though.

Are you saying WTC7 was built like a weak ass table? No, I am sure you are not suggesting that. Perhaps then you were implying only sections of WTC7 were built like a weak ass table? No, I am going to give you more credit than that. Ok so maybe your point was that elements of WTC7 could act like a weak ass table? No, I am sure you are aware steel framed buildings and tables are constructed differently. So… what was your table attempting to prove?

If you wanted to make your table experiment slightly more realistic, how about adding an extra two legs to the perimeter on each side, a further four legs inside those now twelve legs and securing them all together with horizontal beams. As we have made it slightly fairer, now you can remove/cause damage to one or two of the legs, tell me how the loads redistribute and describe how much strength the structure still has.



I am wondering flyingswan, (as I do not think we have covered it yet) the "such damage" you mention above, how severe do you believe this initially was? That is, damage caused to WTC7 from falling debris of the North Tower. Bearing in mind NIST's debris field figure showing only light debris partly reached WTC7 and the fact there are no clear or conclusive images of damage to the building, I believe only damage to the façade and minor structural damage to the outer columns can be claimed at most. Of course, with no real evidence of severe damage it makes the official story even more difficult to sustain.

I have some precedents to WTC7 – First Interstate Bank fire and the Empire State Building plane crash. Of course neither of these buildings came even close to any sort of collapse. There are many other high rise buildings which have suffered severe fire or earthquake damage with not a single one resulting in complete, virtually symmetrical, freefall collapse. We all know that, barring controlled demolition , that has only happened three times in history, all on 9/11.

Oh, it's just a simple problem to illustrate why the "common sense" of an untrained individual is no substitute for detailed engineering analysis when it comes to a complicated problem like a building collapse. And, yes, these basic principles apply just as much to massive steel-framed buildings as they do to weak little tables. By the way, I'm glad you agree with my diagrams. Do you understand now why the following statement of yours is so deeply flawed?

QUOTE(Q24 @ Jul 10 2007, 06:29 PM)

Estimating a factor of safety of 2 (it is probably a lot higher than this) on the main columns, that would necessitate every single column needing to be weakened 50% just to reach its load bearing design capacity. Or even if fully half of the area of the building had severe fires then the columns in that area would need to be weakened 100% (melted) to reach its load bearing design capacity. Knowing that these fires were not engulfing the entire area of the building and cannot melt steel, neither of the above can be true.

My simple little diagrams were designed to show you that you're making some pretty bad assumptions here. In my example, with an assumed safety factor of 2.0, removing just 25% of the columns resulted in the remaining structure reaching or exceeding it's load-bearing capacity.



Now you're starting to understand! I can't tell you how the loads redistribute in a complicated structure like that, at least not without complete construction details and a lot of complicated analysis which is well outside my area of expertise. But then, that's precisely the point I'm trying to make here.

No-one appears to have got a photograph of the south side of the building, though there are photos showing a chunk missing from the SW corner. However, according to this eyewitness the damage was substantial:
http://www.firehouse.com/terrorist/911/mag...e/gz/boyle.html


Neither of your precedents are that impressive. One was a fire without any impact damage (and yet "It is humbling and terrifying to realize how close we came to losing control of this fire!") and the second involved considerably less damage from the aircraft impact - half the speed with a much smaller aircraft.

incorrect-- apparently you missed the "is nist faking it thread" where coughymachine posted an image taken of the south side that he even admitted the photographer(one aman zafar i believe) claimed to have taken the image after the collapses of towers 1 and 2 and before the collapse of 7-- and guess what?? the major damage claimed by nist and fema was not present in the image meaning that the damage was caused after the collapses and not by debri as claimed-- even more damning is video where firefighters were calling home and then a "HUGE" explosion rocks the entire block and a terrorfied firefighter then approaches and pleads "we've gotts get back.....SEVEN IS EXPLODING" as he gestures towards the direction of bldg 7 implying the explosion captured in the video was indeed bldg7 being rocked by an explosion and very likely the cause of the damage caught in later images-- here is the original image along with an isolated close up of the corner compared to the same corner AFTER the explosion and ensuing damage--
original

close-up comparisson of damaged corner with isolated corner from the original image above

link to original of image containing damage
firefighter video where it is proclaimed "SEVEN IS EXPLODING"
firefighter video-"seven is exploding!"

Err - that the "chunk missing from the SW corner" that I referred to. The south side is hidden in those photos, which are taken from the NW.

the damage pictured in the comparisson and link is the damage referenced to by nist in instigating the collapse-- which was obviously NOT caused by falling debri from the collapse

No it isn't, see page 20 of this presentation, which shows the difference between the small region of damage at the SW corner and the much larger region in the centre of the south face:
http://wtc.nist.gov/pubs/WTC%20Part%20IIC%...pse%20Final.pdf

No, I believe my comments are still essentially correct in that WTC7 could have withstood every structural element being weakened 50% or even half the elements being destroyed 100%. Obviously I was giving the most extreme example of what I believe the building could have withstood. No more extreme I might add than your example of wiping out 25% of support on the perimeter of a weak ass table then saying “look it falls just like a building would!”



Ok, a table structure with 12 outer legs and 4 inner legs is too complicated for you. Or perhaps it is fairly simple but you do not want to admit how much strength the structure would retain after losing one or two supports. At least, with those extra supports, I am sure you could agree that the load redistribution caused by damage to one or two of them would be far more evenly spread than in your extreme example? Also you must agree the additional supports would greatly reduce any tilting/pulling effect? With certainty you can agree that the structure would not be close to falling and furthermore absolutely not at freefall speed, virtually symmetrically into its footprint.



We are referring to WTC7 here not the Twin Towers. Are you saying a heavy aircraft hitting a structure at speed, pieces smashing their way through the building and causing fire is less devastating than light, gravity driven, debris side swiping the façade of a building?



The damage to the South West corner of WTC7 seems relatively minor to the scale of the building and in any case irrelevant as NIST are promoting the building collapse initiated from a more central position. Regarding that damage claimed to the centre South of the building, NIST know the Tower's falling debris penetrated the building as far as columns 69, 72 & 75 how exactly? We agree there is no clear photographic evidence, then eyewitness accounts do not describe the damage in that much detail and what they do describe is unreliable. For instance, in opposition to the WTC7 eyewitness account you provided, we have former NYPD officer Craig Bartmer stating: -



If NIST do not have any real evidence, it must be accepted that they are fabricating the extent of the damage in a desperate (and failing) attempt to suit preconceived conclusions and fit with the official story.

Sunofone, regarding the NIST and Zafar photographs I do not see how they are relevant. Both were taken after the collapse of the Towers and show the same damage but from different angles. Although both images show the South West corner of WTC7, neither clearly show the South face.

Q24, you've now had two of us trying to show you that your simplistic ideas about structures are simply not valid, but you still don't get it: your global arguments are both inapplicable and numerically wrong and you seem unable to appreciate how load redistibution after damage puts a structure at much higher risk from fire. Don't waste our time any more: pick a structural engineer out of your local phone book and ask for an opinion.

The quote I presented from the fireman seems perfectly consistent with the NIST diagram of the damage. What on earth makes you think that pieces of structural steel and concrete falling hundreds of feet off WTC1 could be described as "light, gravity driven, debris"?

As to Craig Bartmer, what qualification does he have to say how big a hole in a building is dangerous? At least the fireman gave some idea of the actual size (20 stories missing). The quote from Bartmer continues:
"It was that moment, you know, "Get away", and I looked up... and... it was nothing I would ever imagine seeing in my life. And all the things started peeling in on itself and... I mean, there was an umbrella of crap seven feet over my head that I just stared at. Somebody grabbed my shoulder and I started running and the [explitive]'s hitting the ground behind me and the whole time your hearing "thoom. thoom. thoom. thoom. thoom." So. I think I know an explosion when I hear it."
In other word, he heard loud noises (and everybody describes a loud noise as an explosion) as the building was collapsing, not before. He didn't look up because of an explosion, but because someone shouted. Where does that leave CD?

that is rediculous-- there is no way that the images pictured represent the same damage-- the diagrams presented show clearly that there were intact window frames as well as the corner beam still intact in the zafar image-- the evidence clearly shows undeniable destructive damage that occured in between images that was not present after the collapses --

Well how close were you to the collapse and if you were close to the collapse then you must realize you wouldnt be focused on hearing bombs more like trying to run for his life!!

If you are going to revert back to insubstantial waffle, ie “I understand structures and you do not”, while failing to address the issues and answer straightforward questions regarding WTC7, I would say the only person wasting anyone’s time is yourself.

I understand that damage can compromise the integrity of a structure, I disagree with yourself and pericynthion as to what extent of damage is required for a complete, symmetrical, freefall collapse. You: WTC7 was a flimsy construction coming down in a domino effect or like a house of cards due to the initial failure of a single structural column and limited, random fire. Me: a structure of that size does not depend entirely on one or two columns and its massive, fireproofed, steel structure would be only modestly affected by fire. Anyone reading here will decide for themselves which side of the argument is more believable.



The fireman does not state that damage reached to the internal structural columns of WTC7 or say at all how deep the damage was. For all the detail given by the fireman, it is even possible he could have been referring to damage on the South West corner. It very much seems NIST have just assumed, with no real evidence, the damage caused in an attempt to suit preconceived conclusions.

The FEMA (I incorrectly credited it to NIST earlier) debris field figure below shows that only aluminium cladding and lighter debris reached WTC7. The exterior steel columns and other heavy debris fell well short of WTC7. That is why I referred to light debris.



It is just interesting to note the damage to the Bankers Trust building. Seen in the above figure, it is located closer to the Twin Towers than WTC7, on the edge of the heavy debris field. It is also noted in the figure that unlike WTC7, the Bankers Trust building was struck by two sections of heavy exterior steel columns. It would be fair to say then it is very unlikely that WTC7 suffered anymore severe debris impact damage than this. And obviously the Bankers Trust building was not brought even close to its load bearing design capacity, standing for a further 6 years before being deconstructed due to water damage caused by the sprinkler system.



I really cannot see it Sunofone and it is not for want of trying. You are aware that these two photographs were taken from different angles – it appears NIST’s from the North West looking along the West face, Zafar’s from the South West with both the West and South faces in view?

But you obviously don't understand structures, and are misunderstanding the points that I and pericynthion are making.

No-one is saying the building was "flimsy" or dependant "on one or two single columns". Read my posts again. I am trying to explain how a damaged structure can be further damaged by a fire, even though the fire does not have to weaken the steel by more than a small factor, nowhere near the "50%" you keep claiming. This is a basic fact of structural engineering, and building codes require fireproofing and calculations to demonstrate that a building can stand a couple of hours of uncontrolled fire before structural damage occurs. WTC7 was already damaged and the fire was uncontrolled for much longer than the requirement. The "complete, symmetrical, freefall collapse" was not the initial response to either the damage or the fire, but was a consequence of earlier failures in the structure under the penthouse that effectively removed a lot of the buildings' internal structure.

That account was the first that I googled. No doubt NIST has access to plenty of other eyewitness reports of the WTC7 damage. It is obviously not the SW corner as he refers to 20 stories, while the SW corner damage was only 10 or so.

Look at your diagram again. Exterior columns reached that distance in several directions. The data is thus consistent with the possibility that heavy debris from WTC1 hit WTC7, but is not on your diagram because it was lost in the WTC7 debris pile.

If you still don't believe that the south side of WTC7 was severely damaged, here's some more eyewitnesses:

http://wtc7lies.googlepages.com/accountsofwtc7damage

and here's an analysis of the available photo and video record, as best as could be done through the smoke, plus some futher points about the location of fuel oil and electrical transformers relative to the fire and damage:

http://www.debunking911.com/WTC7.htm

no one is denying damage-- just how it got there-- "seven is exploding" --do you NOT hear the explosion?

rediculous-- the trusses collapsed in the alledged pancake yet the time of the collapse does not allow for a pancake scenario when the core box columns are entered into the calculation-- only explosives could move matter that fast-- a pancake cannot occur at 10 floors a second!

You of course have the calculations to back up that statement? Or it it just more "common sense" applied to an uncommon situation?

Well, we saw it all happened and while you are insisting it didn't. Until you provide proof of explosives, traces, source, type of explosive, who planted it. Then you have nothing really but accusations.

I am NOT the one proposing the impossible-- how are you supposed to formulate an equation disproving the impossible?? it is surely up to you to provide some sort of mathematical justification for your preposterous pressumptions

what did we all see happen that i insist didnt? --proof of explosions is in the video of the collapses,eye witness tesimony,remaining evidence(meteorite of fused concrete and steel,dust particulate containing microscopic spheres,angular severed box columns,dying emt and firefighter personel) and the fact that most of the remaining evidence was destroyed and covered up by the ex-prosecuting district attorney of ny,obvious insurance scam and the abuse of power by the bush administration in the face of an inside job mimicking the exploits of hitler which bush's grandfather had millions of dollars seized from him for financing-- you sir have nothing to refute these facts with

The world's structural engineering community's not surprised by the rate of collapse, you are the one claiming it is impossible, the burden of proof is on you.

Edit to add: for a start, is anything wrong with this analysis?
http://www.burtonsys.com/staticvdyn/

your only fooling yourself with this nonsense-- the illusion,like your unsustantiated claims, is crumbling and rational thought will prevail-- these sophmoric attempts at propaganda no longer have the power they used to as people are demanding answers for the obvious flaws you cannot counter or explain

I don't understand what building that is that is falling? That doesn't look like one of the tall twin towers?

the whole argument in that rediculous link rests on the dynamic load ho#$*$#&T which contends that every load bearing member failed simultaneously 12 ft above the floor it alledges could not widthstand the load-- the only thing it doesnt tell you is how that occured! you pathetic attempts at sounding credible are sadly the best you will ever have-- never will the truth be overturned by ludicrous babble such as this

no its bldg 7 which was NOT hit by a plane and that collpased,according to fema, from an integrity failure due to fire and damage from debri of the collapsing tower which did not even result in the collapse of bldg 6 which was in between the s.tower and bldg7-- its quite visually obvious that bldg7,the one in the gif from the article you linked,was imploded using explosives in the manner of a controled demolition but the official govt version says fire and damage and it has contended this for at least five years now officially acting surprised initially and trying to ignore it -- but coming in september when the next loose change video comes out there is going to be an unchallengable whistle blower whose name has been leaked as barry jennings who was head of security for the entire wtc complex and is set to testify publicly about explosions in bldg 7 and casualties that were covered-up --until then jennings will not seek publicity but its not as if there is already enough proof for the demolition of wtc1,2 and 7 --eye witness testimony,video of the collapses and many more details prove the official story is a complete lie and that 9/11 was a false-flag military operation used to instigate the afghan and iraqi war for oil and the destruction of the american republic and our sovereignty

Thanks for the reply.

My opinion is that 9-11 happened because of some angry Muslims, but the government instantly took advantage of it and used it for the current operations in Iraq and Afganistan. It was an accident, a tragedy, and everything else you saids above is valid because they might as well have done all of that on purpose anyway.

just in case you didnt catch it bldg 7 was a 47 story sky scraper that was "demolished" using explosives-- no angry muslim could have wired wtc 1,2 and 7 for demolition-- no angry muslim would have been able to get norad to stand down and allow the pentagon to be targeted 48 minutes after the second tower was attacked removing all doubt as to the nature of the first plane hitting the wtc-- nor could have angry muslims have orchestrated "wargames" mimicking the actual event of commercial aircraft striking the wtc adding false blips on to the faa radar screens further confusing any airforce pilots that may have decided to take things into their own hands tha way it had always been before cheney and rumsfeld issued directives giving them the final say just weeks prior to 9/11-- there is no avoiding what the facts present and its time for all of us to do our part in spreading the news

Your original question was about the speed of collapse, how could ten stories collapse in a second, and if you follow the analysis in that link you will find out. Now you are refusing to address my answer to your question and asking a different one about collapse initiation. Why is that?

Once the top part starts to move, as explained by the NIST analysis of the damage and fire, dynamic loads are what it is all about.

And of course you have the calculations to counter the NIST explanation of how the collapse was initiated? Thought not.

and neither does nist-- all they account for are trusses but they completely leave out the 47 box columns that ran the entire length of the building and that were the largest ever used in construction before and were conviently cut during the collapse into the perfect length to be loaded onto trucks and carted off to china under armed gaurd

you think your slick'r n's*#T dont ya boy-- never was an address refused i merely pointed out its flaw regaurding 12ft of open space-- he claims the top section fell 12 ft hammering the next 70 floors in 7 seconds but,as i already mentioned which you so expertly tried to dodge,he FAILS to mention what exatly happened to the12ft section of 47 boxcolumns as well as over a hundred perimeter columns,drywall,studs and elevator shafts that so conviently vanished in his theory

For starters, according to the Purdue modelling of the impact, about a quarter of the columns were cut in the aircraft impact. See my posts in reply to q24 for how this, combined with the subsequent fire, would put the remaining columns at risk. There is also the point that the columns were only designed to support their vertical load when braced horizontally. If enough crossing elements of such a structure are damaged, the vertical elements will buckle under the static load, never mind the dynamic loads actually applied.

You don't appear to appreciate how much of a building's volume the structure actually occupies. It's quite a small percentage, mainly because the building's owners want space inside. Once a column fails there is plenty of room for the two parts to move past each other. That is why the final debris pile is much smaller than the original building.

You also don't appear to appreciate how fast a structure can fail when it is overloaded, and appear to believe that some magic factor should slow things down. Your argument, both for the initial failure and the general collapse is "I don't believe it could happen that fast without CD". Structural engineers know otherwise. Without any calculations to back it up, your belief is worthless.

haha lol yeah the computer genreation said this-- you dont appear to appreciate the laws of physics-- you just said structural engineers "know" otherwise this MUST mean that they have a working equation that a layman like you could link to-- please elighten us with the "calculations" demonstrating "how" THEY know even one column was cut and how the ensuing fire caused 12 feet of structural steel to vanish allowing the alledged dynamic "hammering" of the structure 12 ft below the initial collapse point which is the foundation of this very theories reason why the structure below disintegrated at 10 floors per second

I am rather disappointed Pericynthion has not replied to this: -


It seems some people have trouble agreeing to an idea that does not conform with the official story.



This made me smile - further proof of the good job the media have done in burying news regarding WTC7. Is it any wonder the truth of 9/11 is not more widespread?



Thank you flyingswan but nowhere in those links is the extent of damage (or lack thereof) to WTC7 apparent. The very few eyewitnesses describe only the height and width of damage to the building facade whilst the pictures/videos are equally lacking in evidence. Therefore the question still stands - how can NIST in their debris figure below claim that damage reached to internal columns 69, 72 & 75?



Oh no wait, it says only "Estimated". So NIST's report is simply theory/hypothesis/guesswork. The answer then to my question: NIST, the main body who have been studying WTC7 for years, by their own admission do not know the extent of WTC7 initial damage or how it came to collapse. Very strange then that NIST are prepared to delve into unsubstantiated and unworkable ideas that damage and fire brought down WTC7 but are unwilling to seriously consider the far easier solution that the WTC7 was intentionally demolished. Why do NIST not produce a study showing what effects thermite would have on WTC7?

Just out of interest flyingswann, do you believe the Bankers Trust Building, which was closer to the collapsing Twin Towers than WTC7 and therefore likely suffered at least as much damage, would have collapsed had it been unfortunate enough to catch fire?

Well, I'm sorry to disappoint you, but I didn't respond because I thought flyingswan summed things up rather well with this:

QUOTE(flyingswan @ Jul 26 2007, 06:55 AM)

Q24, you've now had two of us trying to show you that your simplistic ideas about structures are simply not valid, but you still don't get it: your global arguments are both inapplicable and numerically wrong and you seem unable to appreciate how load redistibution after damage puts a structure at much higher risk from fire. Don't waste our time any more: pick a structural engineer out of your local phone book and ask for an opinion.

Since you're asking, though, I'm quite happy to go back and revisit your questions:


No, I don't agree at all that that would necessarily be the case. It depends on the specific design of the structure and the type and location of the damage. You're making a bad assumption because you don't understand the basics of structures.


No, I wouldn't agree with that as a blanket statement. It depends on the specifics of the design. Also, tilting or shifting of the load is not necessary to cause an uneven reaction in the supports.


Again, I can't agree with that. It depends on the specifics of the design and the damage. I'd also point out that WTC 7 did not collapse at freefall speed, nor did it collapse completely symmetrically or completely into it's own footprint. You're conveniently ignoring the slow collapse of the east mechanical penthouse, which sank into the building about 8 seconds before the outer walls of the building began to fall.

As for the problem you proposed in your quote above, yes, that IS too complicated for me to easily analyze. If you understood structures, you wouldn't have to wonder whether or not I'm being honest with you (I am). Let's take a look at a different problem that illustrates the same points.

Assume we've got a horizontal beam held up by, say, seven evenly-spaced rigid supports:


Imagine this as a segment of a support wall on one floor of a building. To keep things somewhat simple, let's assume the horizontal beam is a simple linear-elastic beam and that the vertical supports are fixed, rigid members. The horizontal beam is clamped at the two end supports, and the middle supports are simple pinned joints.

Let's further assume that we've got another "floor" above this one with the same set of vertical supports bearing down on the ones I've shown here. We'll assume that the load from each of these upper supports is 100 units of force (Newtons, pounds, etc. -- the units won't matter here. I'll use "pounds" from here on just because "units" sounds awkward ):


What we have here is a statically-indeterminate beam problem. This is a much more simple model than the wall of a real building, but it will serve to show how loads can redistribute after damage.

With our little model undamaged, let's figure out the loads we're carrying in each of our seven vertical supports to hold up the total 700 pound load. This one is easy:


The reaction force in each of our supports (the red arrows) is 100 pounds. Makes sense, right? As in my earlier table example, let's assume a safety factor of 2.0 for our vertical support columns. We'll say they can support a total load of 200 pounds each before they fail.

Things get a bit more interesting when we damage the structure. Let's assume that a piece of debris has smashed into our model and knocked out support column 3. The "upper floors" have not been affected, so we still have our original seven 100-pound loads bearing down on our structure. We now only have six remaining support columns to carry the total 700 pound load, though. If the loads redistribute evenly (as you appear to believe), each support will only carry 117 pounds and will be nowhere near their 200 pound failure load.

To actually solve this problem, I've used a bit of software set up to analyze this type of beam problem. Here is the result I got:


Wow. That's not a very even load distribution, is it? Even though support 3 was originally only carrying a 100-pound load, supports 2 and 3 are now carrying a total of 155 extra pounds. They've picked up all of the load from support 3 plus part of the load originally carried by supports 1 and 5, which are now loafing along at 69 pounds each. The small diagram at the bottom of the image is an output of the analysis software. It shows in red a greatly exaggerated view of the horizontal beam's deflection under the applied loads.

At 181 pounds, support 2 is getting pretty close to it's 200-pound failure point. Now let's assume that a fire has started in our structure near support 2. If the heat of the fire weakens support 2 by only about 10% (i.e. reduces it's max load capability to 180 lb), support 2 is going to fail.

Let's re-run the analysis with both supports 2 and 3 failed:


Now we have a major problem. Supports 1 and 4 are both loaded beyond their failure points. They'll immediately fail, followed quickly by the remaining supports. Our structure collapses. We had seven supports, each with a safety factor of 2, yet it only took the destruction of one single support and a 10% weakening of a second support to completely fail the structure.

Again, this is just a simple textbook-type problem, not a real building wall. It does illustrate rather well, though, that having multiple support points does not necessarily help to spread out extra loads due to damage. In my little example, some supports saw dramatically increased loads while others actually had their loads dramatically reduced. Support 7 was hardly affected at all. Can you see now why "common sense" doesn't work well here?

I'm an aerospace engineer, not a structural engineer, so this type of analysis is a bit outside my area of expertise. If I've made any mistakes in my work above, please do correct me. I would like to see more than a simple dismissal of this example as a "weak ass table," though.

I didn't ask you for comparable events. I said...

The collapse of WTC 7 cannot be validated by historical precedent, experimental replication, or even just good old, unscientific, "common sense".

In other words, no solid evidence exists and/or supports the official claim. That is the original claim, which has not been backed up by evidence and calculations.

The east penthouse collapse was essentially a separate event, occurring shortly before the second event. It's the second event which is being referred to - the entire structure collapsing, which was at freefall speed, uniformly, and symmetrically.



The problem is that structures don't go from a totally stable condition, to instantaneous, complete failure at every support point.

Structures can certainly give way, bend, warp, etc. as they begin to fail. But they don't go instantly from point A (structurally stable) to point B (simultaneous, symmetrical, complete failure).

That's why the CD industry gets the big bucks. Because that's the only method that can make a building immediately go from point A into point B.

You obviously don't understand how engineers use computers. The laws of physics and the equations engineers use are part of the computer program. These programs are used for all sorts of structural analysis, static and dynamic, and are validated against experiments. In my professional lifetime, I've seen the solution method of these equations change from spending days doing the arithmetic to solve a large matrix equation to a fraction of a second running a computer program. As you add more elements to a structure, or make the problem dynamic instead of static, you rapidly reach the stage where trying to do the calculations without a computer becomes impractical. That is why pre-computer buildings are generally over-designed for the loads they carry,without the precision available from computer modelling the only alternative is to use larger safety factors.

The penthouse was the key to the whole collapse. It's fall must have taken out a lot of the internal structure of the building, which is why what was left then fell at almost freefall speed, fairly uniformly and only symmetrically if you ignore the bit nearest the penthouse obviously going a floor or two ahead of the rest.

Obviously, the WTC7 damage is not well documented, which complicates the analysis of what exactly happened. However, if some plausible damage state that is not inconsistent with the available data can be shown by analysis to lead to a collapse, what is the problem? Why is CD a "far easier solution"? How do you prep a building for CD without any of the building's users noticing? How does your CD set-up work after being exposed to several hours of fire?

Just giving my opinion on the Bankers Trust Buildingwithout any knowledge of the building's structure, I would say that there appears to be severe structural damage and I would not have been surprised if a subsequent fire had led to a collapse.

I believe you know very well that I was referring to an adaptation of your own ‘table theory’, simply adding more supports to make it slightly more realistic. Therefore, it was not a blanket statement and you know the design of the ‘table’ (you designed it yourself )! That you have disagreed with the blatantly true statements I made, ie a 16 legged rather than 4 legged structure would provide better load distribution, less tilt/pull effect and would not collapse from damage to a few legs, shows how biased you are and lowers your credibility on this subject.



Well anybody can see this is not a weak ass table… though it is a weak ass bridge No, seriously…

I could start off asking how exactly the 31 unit figure taken from columns 1 and 5 was produced. I could argue that to achieve such fluctuating load distributions we would have to assume a non-rigid building. But those points are irrelevant because there is a terrible glaring error in your work – the whole rest of the building is missing!

The mistake you are making is to take a small section of a building (a single wall in this case) and then treat it as a whole structure in itself. What are the other 3 walls and internal structure on many levels doing whilst your own wall is flopping about the place? Obviously I do not expect you to be able to carry out your figure work on a building the size of WTC7 but at least a degree of relevance to a real building would be appreciated. What you are effectively doing in the diagram above is wiping out over 14% of an isolated section of structure in one go whereas damage to a single column of a whole building such as WTC7 would equate closer to 1-2% of its entirety.

Also your examples, both with the ‘table’ and ‘bridge’, are implying that load redistribution in buildings does not actually work effectively whereas we know that in real life it does! Here is a good example I am sure you will recognise: -



Using the logic of your ‘bridge’ example, as it had lost approximately 1/3 of its structure across a section of the North face, WTC1 should have suffered an instant collapse. But the structural damage here did not cause a collapse or even any sagging of the columns above the impact hole, suggesting that the load distribution of the building through its core and remaining perimeter was working very well indeed. Why is it that your example works so differently from what we see above?



All well said flyingswan. Do you know how much you sounded like a ‘conspiracy theorist’ then? You admit that yourself and NIST are not dealing with facts but are seeking out some “plausible damage state that is not inconsistent with the available data”. We are not on such different paths then after all. The problem is that while analysis struggles to achieve any conclusive results on how relatively small damage and fire brought a complete collapse of WTC7, the very plausible option of controlled demolition is for no good reason being ignored.


Easier in that not everyone by a long shot can agree on relatively minor damage and fires causing the collapse of WTC7, but all can agree that placing cutting charges/explosives on the correct columns would cause the effect we saw.

This is how you do it with no one noticing: -

This is how you negate the effects of fire on a CD setup: -


Does anybody believe it was absolutely impossible for explosives/cutting charges/thermite to have caused the same results as falling debris and fire?

That theory doesn't make any sense. The building collapse initiated from the bottom floors.

Wherever it started, the first visible sign was the downward movement of the penthouse, meaning that the structure somewhere beneath it had given way. It is immaterial to the subsequent collapse how high on the building this was, because the penthouse and its supporting structure falling through the rest of the building would have produced the same size of hole anyhow.

I did not admit that "NIST are not dealing with facts", I said that the facts are incomplete. The NIST analysis fits what facts are available, but has to make assumptions about those that are not. On the other hand, the CD theory fits no facts, it is all assumption.

CD charges would have to be placed on the structural elements, which are only accessible with major disturbance to the building's contents. Stealth placement is not plausible. You then have to accept that the CD system, which includes electronics and electrics as well as the charges, has to function after the impact damage and fires. The CD theory actually conflicts with one fact, as I only learned from this thread a couple of pages back: Bartmer's statement that the collapse began before he heard his "explosions".

So in your own words, NIST’s study is based on “incomplete” facts and “assumptions”. Yes I completely agree. Let us list the facts that NIST do have supporting their theory WTC7 was brought down by damage and fire: -

• Debris damage to South face
• Limited fires on a dozen floors

NIST have 2 facts they are working with, that is it. Now let us list the facts supporting an inside job/controlled demolition of WTC7: -

• Explosions in the building - see original post and video evidence
• Characteristics of a controlled demolition – freefall, virtually symmetrical collapse, CBS sum it up well
• Temperature of the rubble pile being in excess of 700^oC
• Building tenants including CIA, Secret Service and Mayor's Emergency Command Bunker (motive)
• Larry Silverstein’s “pull it” comment
• John Kerry’s the building was brought down in a “controlled fashion” comment
• No steel framed building in history ever having collapsed in this way before except in the case of controlled demolition
• Mossad agents driving a van full of explosives are arrested in the area on 9/11 - full info here

It is clear that even staying very specific to WTC7, the facts for an inside job are outweighing the ‘official’ story facts. I could easily add 100 more facts which indirectly support the idea WTC7 was intentionally demolished.



Structural elements in elevator shafts, in service areas, on mechanical floors and perhaps the secret service owned offices could be accessed without suspicion being raised. If you read my above scenario about how explosives/charges could have been placed you would realise that stealth was not necessary – the ‘demolition team’ would be legitimately in the building carrying out, as far as anyone is concerned, maintenance work.

I am sure if the building was rigged at multiple locations on numerous floors, after the relatively minor damage and fires, there would be plenty of explosives/charges remaining intact to bring down the structure.

Here is a short CGI clip I came across showing the basics of WTC7's structure.

I found it interesting and as I had not seen it posted here before I just thought I would share.

Most of that is hardly evidence for a CD alone. The OP is consistent with the witness losing track of the events outside the building, the "explosion" is simply a loud noise consistent with a minor structural failure - to be CD it would have to be timed to the start of the main collapse, and Bartmers evidence does not support that - the temperature in the rubble is consistent with the fires and the additional energy lost by the building when it fell, your "motive" is pure speculation, "pull it" isn't a term used in explsive CD, Kerry appears to be doing the usual politician's trick of winging it when he is unfamiliar with the situation, I don't recall a similar building being brought down by CD either, and even if white vans full of Mossad agents were involved, how is that relevent to the fall of WTC7, shouldn't the explosives be in the building, not in a van?

I can easily state in my opinion the façade damage and fires in WTC7 were not nearly enough to cause a collapse imitating a controlled demolition but it does not change those 2 facts which do support the official story. Same as your interpretations do not change the many facts which do support an inside job.

Facts are facts; you can interpret them to mean different things but at the end of the day they are still facts. And the facts for an inside job in most aspects of 9/11 far outweigh those for the official story.

One more note – I would seriously question the interpretation skills of anyone who does not find relevance in a group of Mossad agents in New York on 9/11 who were seen celebrating the collapse of the Twin Towers and were subsequently arrested with a van full of explosives.

?? The east penthouse and its supporting structure didn't fall through the rest of the building. Even NIST doesn't suggest that occurred. More important, neither does any of the evidence (photos, videos, etc.).