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Are Millions of Business People At Risk of Dying In Collapsing Buildings?
This is one in a series of safety-related public service announcements.
Death Traps?
Millions of people work in or visit high-rise buildings … assuming the buildings were more or less safe.
But it turns out that there is a severe, lethal risk of sudden collapse in even the best-made skyscrapers in America, Britain, Germany, Japan and other nations worldwide.
A New Understanding
Before 9/11, no modern steel-frame high-rise building had ever collapsed due to fire.
9/11 radically changed our understanding of architecture and engineering …
Specifically, 3 steel-frame buildings collapsed on that day. That includes one that was never hit by a plane, and had only small, isolated office fires prior to its collapse.
This was unexpected, as much hotter, longer-lasting fires have never before brought down a modern steel-frame office building. For example, the 2005 Madrid skyscraper fire “reached 800 degrees Celsius (1,472 F), said Javier Sanz, head of Madrid firefighter” and lasted some 20 hours without collapsing.
In other words, officials who write building codes, architects and structural engineers had never before worried about small office fires causing office buildings from collapsing.
Appendix A of the Federal Emergency Management Agency’s World Trade Center Building Performance Study notes:
In the case of the fire at One Meridian Plaza, the fire burned uncontrolled for the first 11 hours and lasted 19 hours. Contents from nine floors were completely consumed in the fire. In addition to these experiences in fire incidents, as a result of the Broadgate fire, British Steel and the Building Research Establishment performed a series of six experiments at Cordington in the mid-1990s to investigate the behavior of steel frame buildings. These experiments were conducted in a simulated, eight-story building. Secondary steel beams were not protected. Despite the temperature of the steel beam reaching 800-900 °C (1,500-1,700 °F) in three tests (well above the traditionally assumed critical temperature of 600 °C [1,100 °F]), no collapse was observed in any of the six experiments.
Underwriters Laboratories tested the steel components at the Twin Towers and found they could withstand fires for hours without failure:
“NIST [the government agency - National Institute of Standards and Technology, a branch of the Department of Commerce - responsible for investigating the collapse of the 3 buildings on 9/11] contracted with Underwriters Laboratories, Inc. to conduct tests to obtain information on the fire endurance of trusses like those in the WTC towers…. All four test specimens sustained the maximum design load for approximately 2 hours without collapsing… The Investigation Team was cautious about using these results directly in the formulation of collapse hypotheses. In addition to the scaling issues raised by the test results, the fires in the towers on September 11, and the resulting exposure of the floor systems, were substantially different from the conditions in the test furnaces. Nonetheless, the [empirical test] results established that this type of assembly was capable of sustaining a large gravity load, without collapsing, for a substantial period of time relative to the duration of the fires in any given location on September 11.” (NIST, 2005, p. 140).
Other fire tests have also failed to cause failures at high temperatures.
So the collapse of World Trade Center Building 7 on 9/11 (not hit by a plane) was a surprise … and should be a huge concern to the millions of people who work in office buildings worldwide.
To get to the bottom of this issue, Washington’s Blog reached out to a former manager at Underwriters Laboratories – Kevin Ryan – to seek reassurance that the danger was small for the millions of financial services industry workers, business men, lawyers, web executives, and others who work in office buildings:
[Question] Wasn’t the steel used in the Twin Towers and Building 7 of inferior quality? So as long as builders use better-quality steel, can’t we be assured of safety?
[Kevin Ryan] The steel used to build WTC Building 7 was the standard grade for high-rise construction–still used to this day–called ASTM A36 grade steel. It was not inferior in any way from the steel used to make many of the other high-rise buildings in America.
For the Twin Towers, fourteen different grades of steel were used in the construction, including A36, which has a nominal strength of 36 ksi. The other grades used were higher strength steels like 100 ksi WEL-TEN steel which was manufactured in Japan and shipped to the States. The steel used in the Towers was actually far superior to typical structural steel.
The official government reports on the destruction of the WTC buildings did not find any problem with the quality of the materials or construction methods used. And although those reports did make some recommendations for changes to building codes, those changes have not been incorporated in municipal codes or adopted by the building construction community.
[Question] You write in Foreign Policy Journal:
“And if people actually understood and believed the official account of what happened at the WTC they would not enter tall buildings because in doing so they would be putting their lives at risk.”
What do you mean?
[Ryan] What I mean is that high-rise buildings are designed and constructed to withstand fires that are much worse than what we know existed in WTC Building 7. My former company, Underwriters Laboratories (UL), plays a big part in that process. We know that UL did the fire resistance testing that was behind the selection of the steel components for WTC7 because that fact is in the NIST WTC7 report. Therefore the steel columns and floor assemblies should have withstood 2 to 3 hours of intense fire in a testing furnace, as required by the NYC code. But on 9/11, the fire lasted only 20 minutes in any given area, a fact that NIST admits, and the entire structure was destroyed due to an inexplicable failure to resist fire.
Moreover, NIST abandoned its previous hypotheses that suggested the destruction of WTC7 might have resulted from diesel fuel fires, or damage from falling debris, or the design of the building. In the end, NIST said that it was only the effects of the fire fed by office furnishings, on fully-fireproofed steel components, that caused the total destruction of this 47-story building. And since no actions have been taken to retrofit any existing high-rise buildings, we must assume that what happened to WTC7, according to the official account, could happen to any tall building that experiences a typical office fire.
No Change (?!)
Given that 9/11 totally changed our understanding of how dangerous small office fires could be, we couldn’t believe Ryan’s claim that “changes have not been incorporated in municipal codes or adopted by the building construction community.”
So Washington’s Blog contacted Richard Gage, a practicing architect for more than two decades, who has worked on most types of building construction, including one project which used around 1,200 tons of steel framing:
[Question] Have high-rise architects and engineers changed how they build skyscrapers, to prevent collapses after 9/11?
And have they changed how they build skyscrapers to prevent office fires from knocking down steel buildings?
[Richard Gage] No – they haven’t made any structural changes.
No structural changes?!
Either building code writers, architects and engineers are cavalierly ignoring this catastrophic new understanding of the extreme danger of small office fires, or the investigation into the collapse of World Trade Center building 7 on 9/11 was flawed.
No wonder New York residents have launched a High Rise Safety Initiative to try to protect the safety of those who work or visit office buildings.
Postscript: Until this issue is resolved through a complete revision of building codes and architectural and engineering practices, we recommend that everyone stay out of office buildings. Because if even small office fires can cause the whole building to collapse, it’s just not worth the risk to go inside.
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Actually, steel frame structures are much safer than concrete structures.
It is the concrete structures which should be banned.
I disagree that steel frame structures are ANY safer than concrete. Bit since there are so many DIVERSE risks to safely mitigate in different building designs with varied purposes, it's a pointless argument, even before getting into design specifics.
I also don't think my laptop keyboard would react well to me pissing on it just for yuks.
But actually offices with high human density are extremely dangerous regardless of the basic construction materials, as both stupidity and biological agents can be highly contagious, so perhaps we should just ban all buildings where people congregate in large numbers, for the children (and the future solvency of Obozocare).
."(and the future solvency of Obozocare)"
Uuuhhh, it started life insolvent (and bereft) and forever shall it remain.
Hey Dorks!
The article says: if building 7 went down and the story is true, then OTHER similar building must be unsafe.
Can't have it both ways.
You may have to chip the cement out of your stubborn fixated brain to get it: fuckers did 911 and they continue to profit from it and you are stupid.
What the fuck is this shit? Why is this on ZH?!
Welcome:
i don't accept the idea that longevity on a board
implies credibility.
some with 3 plus years on the site are also
incapable of comprehending the nature of the
beast under discussion.
Just another uninformed fucking asshole or paid shill.
Yikes. The author needs some serious lessons in risk. Millions and millions of people "survive" going to office buildings every day. Do the most simple of statistics. Getting to the building is orders of magnitude more dangerous. Staying in your own house is likely more dangerous.
Did you see that thing that flew right by you?
That was "the point".
you really are something, aren't you pondscum23?...you are just some kinda piece of work. not really runnin on all 8 cylinders, are ya?
look, whether it's defective genetics, sloth, inbreeding or public schools, i wouldn't hazard a guess (y'all know janus, PC to the MAX!), and i do not care. i blame you for your deficiency; i hold you personally responsible for your moronic comments.
and so i have made a few decisions. first of which, you will not ever be allowed in the house. secondly, your servitude will consist of a period to include the entirety of your remaining years (i did not for you choose this unhappy fate; twas instead you, pondscum23...you are a slave. you were born that way; you think that way; you will die that way. alas. no one weeps for you). thirdly, your servitude will be a grim affair; lots of sweat-making toil in your future...i'm leaning to salt-mine or chimney sweep. anyway, it won't be pleasant; and i promise to see to it.
don't sass me, boy! janus is handy with a whip.
http://www.youtube.com/watch?v=1CpJpGF8lS8
tell me your name,
janus
What some rich country or fella needs to do is crash a jet into a building similar to the WTC's and lets tape it and really SEE what happens. How much would it cost to rebuild a basic WTC 1 and crash an old plan into it? That would be fasinating to say the least. We could then put all this bullshit to rest. Theres no doubt in my mind that it would look far different than what we "saw" on 9/11
Anyone rich enough to do this?
Ocean22
You would never need to do that.
The Twin Towers that were met with aircraft as you will recall absorbed all of the energy of those two planes and sat there for more than 20 minutes before the onset of symmetrical collapse occured at near free fall acceleration. This is the whole point premise and more importantly "guarantee" of what made the Commission Report such a farce. No mention of this anywhere in their investigation and how significant that "smoking gun" is in explaining how those building were built to withstand that kind of disturbance from a similar sized aircraft and that no fire ever has brought down a steel frame structure in the history of modern architecture.
Then 8 hours later we have a third building at 47 stories tall that does the exact same thing without an airplane hitting it?
End of story!
PNAC, Bush Family, Cheney and Company, Robert Reuben, Richard Pearl, Aipac, Mossad, Saudi Royal Family, Blackrock, Investors who shorted airlines on 9-10. Rumsfeld, Defense Industries, Military contractors... perhaps they can afford such a building, and be in it at the time of the test.
WTC was built like Aon Tower is built in Chicago, makes it prone to collapse in a way that a girder structure is not, and the PE of the top floors of WTC 1 or 2 were much higher than that needed to destroy surrounding structures including WTC7. Gypsum walls to the stairwell core, no support columns, open floor plan one acre in size, nested tubes and sprung floor joists.
I ran the figures for what bomb size WTC7 was designed to withstand, figured out the joules involved, then summed the floors of WTC and their PE and KE.
The PE and KE were many times the energy required to melt many pounds of steel and to destroy WTC7.
Unfortunately for you idiots, you don't understand maths, physics or why those structures failed when the ESB did not when hit by a plane in 1947.
The number of downvotes to this comment will indicate your level of stupidty.
The greater the number of downvotes I get, the greater your individual and collective idiocy.
Let's see who invokes appeal to authority fallacy first...
Yep, we're all idiots. We don't understand 'maths', it is unfortunate.
High school physics is all you need to figure out 911 was a controlled demolition
Tower 7 collapsed at free fall acceleration, meaning that a bowling ball dropped from the top of the building at the instant the collapse started would stay level with the roofline as both accelerated downwards towards the ground
This can only happen if all structure in the building suddenly disappeared, had all structure turned to jello it would have caused some resistance and the falling bowling ball would precede the building roofline , there was no resistance
I encourage all readers unfamiliar with the events on 911 to look up Architects and Engineers for 911 Truth, and pay no attention to government disinformation trolls
Hey man,
You had me until "Unfortunately for you idiots..."
I appreciate your comments and feedback, but can you pull back on the name calling?
Some of us are very intelligent, and some are average, but their are many views, so please inform, educate and generate thought on yours, without the name calling.
I actually like to be challenged intellectually and to know as many views on something as complex as 9/11 as possible.
Just some respectful advice.
Watching the videos about how the WTC Towers were built, and then watching the videos about how they collapsed, is enough to drive the conclusion that the official story is an insane contradiction of common sense physics.
What it actually took to make those Towers collapse they way that they did is a different issue. The way that they collapsed was SO STRANGE, that it takes a STRANGE STORY to get close to explaining it!
However, the fact that there were never any proper investigations allowed to happen, when they should have been, is enough to prove that there was a deliberate, illegal, cover-up of whatever it was that DID cause the WTC Towers to suddenly collapse.
"Truthers" never point out that most of the diagonals shown are the cranes, not the building.
If CD is such a slam dunk case, why the deception? How does that help "truth"?
why the deception?? really, you have to ask that?
and this picture proves what exactly?
Photo shows the extensive amount of steel in the core structure.
The stronger central core would have remained standing while the weaker outer shell collapsed,
if it were a "natural" collapse,
but instead it all fell together exactly at the same time, weak and strong,
only because of controlled explosive demolition.
rrright, and when the weaker outer shell collapses, the connections towards the inner central core would have miraculously all been sheared off without pulling it down too <facepalm>
the connections between the core structure and the "outer shell" was significantly weaker than either of them. The core was the strongest element. By a lot.
So no, the collapse of the outer wall would not "pull down" the absolutely massive core structure. If I have a chain of 1000 links, and each chain is rated to hold 1000 pounds, but one has been damaged and can only hold 100 pounds...
guess how much oppositional force the chain as a whole can withstand?
The supporting trusses {weren't they damaged by the fires too?? lol} had nowhere near the strength to pull down {or pull apart} the core. It's not even close. It's like arguing in my example above that the chain as a whole can support, say 500 pounds. It is just false.
Moreover, if the shearing of the walls could exert desttructive shearing force on the core columns, via the connections, this would have been exceedingly unlikely to be an "even" process - the building should not, then, have collapse straight down, but in the direction of the side with the most core shearing.
Indeed, the pyroclastic flows and the sheer evenness of the collapse is what made some people suspicious right away. It took me years to ever begin to suspect anything different from the official narrative, just because any alternative seemed even more crazy. But years later, watching footage, when it was explicitly said that "fires" had weakened the steel that I began to do some googling.
But you don't have to even address the collapses at all. Just start with Lucky Larry, the leases, and those simulations being run the same day. You might also look into the 7/7 subways bombings in London, where they also happened to have very similar drills going on {and there's some suggestion "drills" were going on during the Boston marathon bombing, but I'm not certain about that and I don't see a reliable confirmation really}
Bombing drill on 7/7:
70. On 7/7 it is undisputed that Vizor Consultants held a bombing drill in London Underground. Peter Power, Managing Director of Vizor Consultants revealed himself on 7/7 on BBC. The following quote is from a later interview:
“POWER: At half past nine this morning (7/7/05) we were actually running an exercise for a company of over a thousand people in London based on simultaneous bombs going off precisely at the railway stations where it happened this morning, so I still have the hairs on the back of my neck standing up right now.
HOST: To get this quite straight, you were running an exercise to see how you would cope with this and it happened while you were running the exercise?
POWER: Precisely, and it was about half past nine this morning, we planned this for a company and for obvious reasons I don't want to reveal their name but they're listening and they'll know it. And we had a room full of crisis managers for the first time they'd met and so within five minutes we made a pretty rapid decision that this is the real one and so we went through the correct drills of activating crisis management procedures to jump from slow time to quick time thinking and so on. »
http://www.bbc.co.uk/radio/aod/mainframe.shtml?http://w...
See also: http://www.cbc.ca/MRL/clips/rm-lo/charles_disasters0507...
What are the odds of this coincidence? Was the possibility of inside information that might have gotten into the hands of the alleged bombers investigated?
What is the result? What’s the name of the company for which the exercise was conducted?
Sorry, you got that wrong.
The outer shell was the strongest element, as only it was designed to take up the massive wind forces that can occur.
Swing and a miss. You don't know what you're talking about - obviously.
And please don't bother showing us you actually know anything - never let facts get in the way!
Yes, the floor trusses would have torn away from the central core,
and the central core would have remained standing,
if it had been a "natural" collapse,
but instead the core was destroyed by controlled explosive demolition.
Controlled demolition,
controlled news media,
controlled Government.
Controlled by who?
The Dancing Israeli's.
Both cores were the last to fall, still standing briefly AFTER everything else had collaspsed.
You also miss the fact that perimeter wall slabs and other debris was falling between the columns, splaying them apart.
You guys are really funny, clasping at straws to hold up your wild theory.
How about you offer some examples, where such a case you describe happened before.
You know a tall steel structure where part of it collapsed while the rest stood standing as if nothing happened?
Windsor Tower Fire had a partial Collapse after burning for many hours consume in flames. Most of the structure was intact.
Why was the Gold moved out of the WTC Vaults beginning in Mid July, 2001 and going through to Septemeber 11?
WHY WAS THE GOLD MOVED FROM THE WTC TO THE NEW YORK FED???
WHY???
That is precisely what occurred. Both cores were the last to fall.
And the photo is disingenuous. All the diagonals are the 4 cranes, not the building.
The core would have remained standing until today,
without explosive demolition,
even if the outside shell and floors had collapsed in a "natural" collapse.
All of it was "Un-natural".
All of it was controlled explosive demolition.
It disproves Leraconteur's claims.
Not at all.
GW acts as a disinformation shill by posting just this photo.
The truss deck structures are the ones around the core - that are the large flats in the photo in which not a single vertical beam is visible.
Google for the construction plans, it's all visible in there.
There is so much redunduncy in the twin towers that it is next to impossible to collapse it by fire. I'd like for some ppl to publicly demonstrate how can they collapse a steel frame with fire.
"There is so much redunduncy in the twin towers that it is next to impossible to collapse it by fire. I'd like for some ppl to publicly demonstrate how can they collapse a steel frame with fire."
They did collapse due to fire. The collapse of both Towers occured within the fire zone.
"So much redundancy" is a meaningless statement. What was so redundant, that it was next to impossible for the Towers to have collapsed due to fire?
I just don't understand how you think som office furniture fueled fires weakened these central column all the way down the structure such that, even as tens of thousands of pounds of materials was ejected away from the structure as floor after floor collapse, the core structure at the levels below, with a 3-4x reduncancy of load carrying capability, would "collapse"
it makes absolutely no sense - these elements can handly X amount of weight, as each floor structure collapses there are mass ejections, lots of material dozens of yard,s but we still get almost freefall speed, and then the structure below offers resistance, and instead of being more able to handle the existing load now with less mass above it, the core structure gets weaker..... but only gives way after the floor right above it has? Not just the floors coming off the core, but the core itself?
Have you actually given this any thought or are you desperate to debunk what you perceive, a priori, as absurd theories?
The jet fuel thesis is absurd - what didn't burn up right away was either too concentrated to cause the damage we'rd supposed to believe, or if it fell down elevator shafts, somehow - far too dispersed. Those building were tremendous, the notion that jet fuel would burn hot or long enough to weaken the core to collapse doesn't make sense, but how the buildings came down don't make any sense without explosives.
The notion that the core structure could push back on collapsing structure multiple floors above, and only fail when much or most of the wait it could previously carry was gone, and only as a result of the action of the floor above it, is batshit crazy. It only happens when there is extra energy in the system to eject tonnes of material, pulverize concrete and steel, and remove virtually all resistance on a timed, floor by floor basis. I'm no physicist, but I'm pretty sure that building was brought down with explosives, and absolutely positive it looked like it during and after the collapse {the molten steel weeks after the event can not be the result of collapse alone}
If you have a theory as to why a collapse "from fires" can recreate the pyroclastic flow and floor-on-floor collapse {wouldnt the jet fuel have pooled to the bottom and weakened the steel carrying the most load first? If it didn't pool at lower levels, why would the core columns below the crash site have been weakened at all from office fires?} and can otherwise look identical to controlled demos - I'd love to hear it.
And I'll second the emotion from the commenter below that "The New Pearl Harbor" is probably the best of the "truther" movies. I can understand not accepting all if its claims, or any particular theory, but I can't understand how a reasonably intelligent person can spend even a modest amount of time looking into not only the collapse of the buildings but the circumstances surrounding the events of that day, the polocy papers of groups like PNAC, who they were tied to, the activities of the Office of Special plans "lie factory" before the iraq were and just who those people were.... and come away and not have some questions... not suspect that there was some fuckery afoot that day.
In fact, the crazy and stupid are the people who accept without question the government's narrative, irrespective of belief in or agnosticism regarding any other theory of the crime.
And it was, let's remember, a crime. A conspiracy to commit murder, destroy records to hide financial crime, and get some wars going to enrich US arms manufacturers, prop up the petrodollar, and remake the middle east so that Israel can be its brutal, expansionist hegemon.
https://www.youtube.com/watch?v=8DOnAn_PX6M
And let's face it, they got away with it, people who are intelligent and sane ergo dubious as to the official narrative ae the ones painted as "truthers" or "nutters" or "anti-Israel" - which invites the same actors to do more of the same shit if they think they can't get the Syria/Iran war going politically.
Of course they've been fucking with Ukraine, and that may end up fucking up their other plans. I'm sure the Chinese appreciate that they're on the menu, too.
We'll see.
In your fucking fantasy world perhaps. Fucking shill.
There is so much redunduncy in the twin towers that it is next to impossible to collapse it by fire. I'd like for some ppl to publicly demonstrate how can they collapse a steel frame with fire.
You must be a total moron to believe that people can be bulshitted and bullied in the way you have attempted. If you so sure of the figures and you model of how the KE (obviously PE does nothing until turned into KE) was transferred to the specific area requierd to cause catastrophic failure at freefall speed. then please post them so that some actual engineers on the board can evaluate your claims. Failure to do so is admitting that you are just trying to BS people into submission.
Oh, and what bomb? Are you claiming that a bomb brought down the towers and not the fires as NIST claims?
The best documentary on the truth of 911 is here. It is so convincing it might even silence the paid governmemt trolls and goons to shame.
http://www.youtube.com/watch?v=8DOnAn_PX6M
Your abiltity to pack multiple logical fallacies into as few words as possible is one of the traits of your brand of un-intelligence.
AKA 9-11 Truther Stem-less Believers
It did not occur "at freefall speeds". I took a stop watch, I watched videos about 200 times and the tragedy for you is that it happened as 'the official version' says, IOW as anyone with intelligence can conclude. You can count the time, it's there and not at freefall. It takes longer than that. You can see that there was no detcord, nor the 20 second delay that occurs in a real controlled demo, you can hear that the booming sounds were not due to explosives but due to percussive impacts of each floor onto the subsequent. You can see that bursts of compressed air are blowing out windows as the building compresses down.
Your technique is classic. You ignore my points, then state 'Ok, then what about THIS'. You guys don't even have the intelligence to comprehend your own logical fallacies in your 'argument's.
My model? My? It's not 'MY', it's science independent of what I think - it's known fact about the weight and height of each floor and the PE and KE are known to anyone with any Maths education at all. You mean to tell me NONE OF YOU bothered to do this simple check? It takes less than an hour to do it.
Just take an Excel spreadsheet, fill it with 116 rows and sum the total of each floor. Perform the calculations - it's 4th grade maths with page one Physics from 8th grade (you should understand and if you don't then your argument is moot). Remove the basement 6 floors, remove anything above floor 20 to account for rubble.
Surprise, the PE of just the top 10 floors was sufficient to melt lots of steel AND exceeded many tonnes of TNT equivalent in joules, far greater than the amount required to exceed known WTC7 calculations. There were another 70 floors with PE to transfer to KE in addition. Lots of energy, far in excess of what was needed.
Since the PE of WTC was about 20 times what was required to do what you all claim could not (George, your ignorance is extremely disappointing), it is logical and reasonable to conclude that when converted to KE, and it was, that a mere fraction was all that was required to 'do the impossible'.
AKA melt steel and destroy WTC 7.
You guys slept through science class, obviously.
You are stupid - and that's not Ad Hominem, it's a result of hundred's of identical conversations with people like you who smply lack even rudimentary maths and phsysics skills and cannot comprehend why what happened happened as it did.
You guys repeatedly state the equivalent that 1+1=3, and in so doing prove your lack of intelligence in this matter.
George's posting a photo of the top mechanical floor structure as 'proof' that WTC was a girder design is just so ignorant it's beyond belief. That wasn't even load-bearing - it was a hut on the top to encase the walls for the electrical and elevator housings. The load-bearing was the core and the 22inch spaced steel tubing on the exterior. That steel 22inch spacing acting like a chimney, funnelling the floors and debris into those below. In addition, inertia would 'right' the building and keep it from falling over.
And so on with every.single.point.you.have.made.
But neither George nor any of you even understand what any of that means.
But hey - 'YOU KNOW' that 'somethings not right when a building just collapses like that'.
You guys are all Dunning - Kruger. None of you are smart enough to realise that you are stupid.
I know - it's horrifying to contemplate that what happened really did. Because that scares you and George SO GREATLY, you all construct an ideology and belief system to help you cope with the horror that is too difficult to bear.\
The horror and truth is this: A bunch of Wahabi-Funded Saudi nutjobs flew two planes into two skyscrapers and used the kinetic and thermal energy of the planes, fuel and passengers to bring down and collapse two structures chosen specifically for their weakness and potential for catastrophic progressive structural pancake collapse to maximise emotional impact, kill thousands, and attack a country.
"George's posting a photo of the top mechanical floor structure as 'proof' that WTC was a girder design is just so ignorant it's beyond belief. That wasn't even load-bearing - it was a hut on the top to encase the walls for the electrical and elevator housings"
The photo is not of the top of the Tower. In the near background, street lights can be seen, as well as the lower floors of the office building on the right side of the photo. The photo was fairly early during construction.
As I wrote above,
You forgot to calculate how much energy was required to break all that steel and concrete into millions of pieces.
Probably more than all that building mass potential and kinetic energy.
Energy initially supplied by the Explosive Demolition devices.
Also consider the local density intensity of energy required, Not diffused, diluted, scattered energy.
The NIST report itself stated that all these buildings fell at near free fall speed. That's the litmus test not your supposed stop watch.
http://www.youtube.com/watch?v=Ii49BaRDp_A
"The NIST report itself stated that all these buildings fell at near free fall speed. That's the litmus test not your supposed stop watch."
Near freefall is not freefall. In fact, the column sections freefalling down were falling quite a bit faster than the Towers were collapsing, even though they were collapsing rapidly.
The force of falling debris stripped the floors off the flanges that connected them to the exterior columns, so the rapidity at which the Towers collapsed is not surprising.
Hi Storyteller, I'm still not getting it, but I must just be stupid. How much kinetic and thermal energy did the passengers add to bring down and collapse the buildings? Thanx.:)