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Post by PhantomWolf on Mar 5, 2007 20:12:57 GMT -4
Yet another 9/11 CT theory that can't stand the light of investigation.
But that's the point, it's not another theory, it's the same old, same old, repackaged and then given a stamp by someone so that he can use an argument from authority.
It might have worked, but he makes exactly the same fundamental mistakes as the original argments (that the towers fell in 9-10 seconds, that the jet fuel fire wasn't hot enough to have melted the colunms, that explosives were responsible for the pools of melted metal, that only explosives could pulverise the concrete.)
These claims have been wrong from the start, and demonstratably so, yet he just makes them regardless anyway, and that casts doubt on his entire claim.
It doesn't matter if it is Simon the pieman or Albert Einstein who says that the sky is green, if all you have to do is look out the window to disprove it then their authority has no founding.
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Post by feelfree222 on Mar 5, 2007 21:34:33 GMT -4
But I cite William Rice, the structural engineer who cast serious doubt about it.Someone that admits not having studied the issue (ie read the NIST and FEMA reports) and simply parrots the already demonstratably wrong and debunked CT rubbish almost verbatium. Just because it has a new stamp on it does change the content. For example: The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds at nearly free-fall speed.By they didn't. Video taken at the base of the towers clearly shows that they took between 16 and 20 seconds to collapse. That is up to twice as long as claimed. But It is the FEMA and NIST report themselve citing the 10 seconds collapse However, in the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire.
Again, totally incorrect, I posted to information a few weeks back about three multi-story steel framed buildings that collapsed because of a fire. They were linked and the fire spread from one to the other. They fell arounf 1 hour, 2 hours and 2.5 hours after the fire was discovered. They are not the only examples either. The much loved Winsor Tower in Madrid had the steel portions of its structure collapse, the bits that survived were concrete (much to the concrete industries joy.) Now while someone is sure to claim that the Winsor tower burned longer, that is irrelevant to the point the Rice made that "no steel building had collapsed because of fire" because the steel parts of the Winsor Tower did just that. His claim is demostratably false.
Comment from the structural engineer "The collapse of a concrete-framed building cannot be compared with that of a structural steel-framed building." so even if it is only the steel part wich have collapsed after a 24 hours raging inferno that is nothing comparable with the one hour fire at WTC.I know there was also the damage done by the plane crash. When he hasn't bothered to do the research and just parrots what is already out there and is shown to be wrong, why should we take any more notice of it now than before.
I dont think he have even bothered reading conspiracy theory site.So I doubt he is parroting what they said.
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Post by feelfree222 on Mar 5, 2007 21:46:48 GMT -4
Well about these so called "major research"The NCE criticised them for not pushing the visual models further to help illustrate their collapse model. They didn't desagree with the collapse model or claim that NIST's model was wrong and it was brought down with explosives, they just wanted better ways to understand and see what NIST was talking about. I never said NCE suggest that explosives were used... The point about NCE is that NIST refuse their demands to show computer visualisations of the collapse of the Twin Towers ... Here some excerpts i bolded the points made by NCE WTC Investigators Resist Call for Collapse Visualisation WORLD TRADE Center disaster investigators are refusing to show computer visualisations of the collapse of the Twin Towers despite calls from leading structural and fire engineers, NCE has learned. Visualisations of collapse mechanisms are routinely used to validate the type of finite element analysis model used by the investigators. The collapse mechanism and the role played by the hat truss at the top of the tower has been the focus of debate since the US National Institute of Standards & Technology (NIST) published its findings (NCE 22 September 2005). NIST showed detailed computer generated visualisations of both the plane impacts and the development of fires within WTC1 and WTC2 at a recent conference at its Gaithersburg HQ. But the actual collapse mechanisms of the towers were not shown as visualisations. University of Manchester (UK) professor of structural engineering Colin Bailey said there was a lot to be gained from visualising the structural response. "NIST should really show the visualisations, otherwise the opportunity to correlate them back to the video evidence and identify any errors in the modelling will be lost," he said.University of Sheffield professor Roger Plank added that visualisations of the collapses of the towers "would be a very powerful tool to promote the design code changes recommended by NIST." NIST told NCE this week that it did not believe there is much value in visualising quasi-static processes such as thermal response and load redistribution up to the point of global collapse initiation and has chosen not to develop such visualisations. But it said it would 'consider' developing visualisations of its global structural collapse model, although its contract with the finite element analysis subcontractor was now terminated. A leading US structural engineer said NIST had obviously devoted enormous resources to the development of the impact and fire models. "By comparison the global structural model is not as sophisticated," he said. "The software used has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgement calls. This doesn't mean NIST has got it wrong in principle, but it does mean it would be hard to produce a definitive visualisation from the analysis so far."
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Post by PhantomWolf on Mar 5, 2007 22:16:30 GMT -4
But It is the FEMA and NIST report themselve citing the 10 seconds collapse
So? Bush himself could say it was 10 seconds, the video shows that it wasn't.
so even if it is only the steel part wich have collapsed after a 24 hours raging inferno that is nothing comparable with the one hour fire at WTC.I know there was also the damage done by the plane crash.
Wow, I even predicted this response. It doesn't matter. He said that steel framing had never failed because of fire, he is wrong. He didn't say it hadn't failed in a hour, or two hours or three hours (he'd still be wrong) he said it had NEVER happened. That is plainly wrong.
I dont think he have even bothered reading conspiracy theory site.So I doubt he is parroting what they said
I disagree. He repeats their claims, most of which are not part of the offical claims, that means that there is only one source he could have taken them from. He also admits to not having read the offical sources (FEMA and NIST) so again there is only one place he could have gotten his information.
The point about NCE is that NIST refuse their demands to show computer visualisations of the collapse of the Twin Towers ...
Maybe you should have highlighted this part:
"The software used has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgement calls.
This doesn't mean NIST has got it wrong in principle, but it does mean it would be hard to produce a definitive visualisation from the analysis so far."
In fact it's pretty much impossible to do what the NEC would like. JayUtah works with super computers that are amoung the most powerful in the world and used for FEA in fluid dynamics. He's already pointed out in previous threads that the visual details of the collapse that NEC would like, are just beyond the computing power we have. Even what NIST did in modeling the floors up to the collapse was pushing our current technology to the limit of what it is capable. Going further and modeling the full gobal collapse is just an impossiblity with our current technology.
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Post by feelfree222 on Mar 5, 2007 22:35:22 GMT -4
But It is the FEMA and NIST report themselve citing the 10 seconds collapseSo? Bush himself could say it was 10 seconds, the video shows that it wasn't. I remember seen that video of that guy running with his camera. But nobody have corrorelated the time of collapse with a hand timer. But obviously he said that the fire and damage at WTC where not enough to brought them down.And he cite John Skilling, the head structural engineer for the Twin Towers, "After the 1993 car bomb explosion destroyed columns in the North Tower, John Skilling, the head structural engineer for the Twin Towers, was asked about an airplane strike. He explained that the Twin Towers were originally designed to withstand the impact of a Boeing 707 (similar in size to the Boeing 767). He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.” I dont think he have even bothered reading conspiracy theory site.So I doubt he is parroting what they saidI disagree. He repeats their claims, most of which are not part of the offical claims, that means that there is only one source he could have taken them from. He also admits to not having read the offical sources (FEMA and NIST) so again there is only one place he could have gotten his information. He have gotten his information based on the PBS programs based on and citing the FEMA and NIST experts. The point about NCE is that NIST refuse their demands to show computer visualisations of the collapse of the Twin Towers ...Maybe you should have highlighted this part: "The software used has been pushed to new limits, and there have been a lot of simplifications, extrapolations and judgement calls.
This doesn't mean NIST has got it wrong in principle, but it does mean it would be hard to produce a definitive visualisation from the analysis so far." I have done it... see page 1. In fact it's pretty much impossible to do what the NEC would like. JayUtah works with super computers that are amoung the most powerful in the world and used for FEA in fluid dynamics. He's already pointed out in previous threads that the visual details of the collapse that NEC would like, are just beyond the computing power we have. Even what NIST did in modeling the floors up to the collapse was pushing our current technology to the limit of what it is capable. Going further and modeling the full gobal collapse is just an impossiblity with our current technology. Good grief...
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Post by PhantomWolf on Mar 5, 2007 22:55:10 GMT -4
I remember seen that video of that guy running with his camera. But nobody have corrorelated the time of collapse with a hand timer.
Why does it have to be a hand timer? And it has been timed. I suppose you could sit there with your own stop watch if you wanted just to make sure the timer is accurate, you'll find it is.
"After the 1993 car bomb explosion destroyed columns in the North Tower, John Skilling, the head structural engineer for the Twin Towers, was asked about an airplane strike. He explained that the Twin Towers were originally designed to withstand the impact of a Boeing 707 (similar in size to the Boeing 767). He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”
Please provide a quote that says, "there would be a horrendous fire from the jet fuel"
It's also debabtable that Skilling was Head Structural Engineer. Yes he come up with the consept, but most sources give that to the man who actually did the details and headed up the project in NY, Leslie Robertson. He has this to say:
He says that his calculations assumed a plane (a 707) lost in a fog while searching for an airport at relatively low speed, like the B-25 bomber. He concluded that the towers would remain standing despite the force of the impact and the hole it would punch out. The new technologies he had installed after the motion experiments and wind-tunnel work had created a structure more than strong enough to withstand such a blow.
He also said:
no one thought to take into account the fires that would inevitably break out when the jetliner's fuel exploded, exactly as the B-25's had.
Although several claims have been made that Skilling says and has evidence that it was, none has yet been forthcoming, despite repeated asking for it (from others who have made the claim.)
Good grief...
Good grief what? Do you know how much computering power it would take to do a visual representation of a FEA on the entire structure of the WTC towers during the collapse?
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Post by frenat on Mar 5, 2007 23:39:53 GMT -4
I seem to remember in the official report when it says 10 seconds, it is in reference to when the first debris hit the ground, not the total time of the collapse.
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Post by feelfree222 on Mar 6, 2007 0:36:41 GMT -4
[ "After the 1993 car bomb explosion destroyed columns in the North Tower, John Skilling, the head structural engineer for the Twin Towers, was asked about an airplane strike. He explained that the Twin Towers were originally designed to withstand the impact of a Boeing 707 (similar in size to the Boeing 767). He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”Please provide a quote that says, "there would be a horrendous fire from the jet fuel" It's also debabtable that Skilling was Head Structural Engineer. Yes he come up with the consept, but most sources give that to the man who actually did the details and headed up the project in NY, Leslie Robertson. Well he is listed as part of the "three major figures" www.civil.usyd.edu.au/wtc.shtml"Yamasaki and engineers John Skilling and Les Robertson worked closely, and the relationship between the towers’ design and structure is clear" Leslie Robertson. He has this to say: He says that his calculations assumed a plane (a 707) lost in a fog while searching for an airport at relatively low speed, like the B-25 bomber. He concluded that the towers would remain standing despite the force of the impact and the hole it would punch out. The new technologies he had installed after the motion experiments and wind-tunnel work had created a structure more than strong enough to withstand such a blow.He also said: no one thought to take into account the fires that would inevitably break out when the jetliner's fuel exploded, exactly as the B-25's had.Although several claims have been made that Skilling says and has evidence that it was, none has yet been forthcoming, despite repeated asking for it (from others who have made the claim.) So they have not thinking about the inevitable fires following a plane crash into the building (?)....Lets suppose it. William Rice the structural engineer maintain that... If a structural steel building could collapse because of fire (and damage on some steel members), it would do so slowly as the various steel members gradually relinquished their structural strength.... Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity and thus remove their structural strength equally over the entire floor, or floors, in order to cause the top 30-floor building segment (South Tower WTC #2) to drop vertically and evenly onto the supporting 79th floor. The 30 floors from above would then combine with the 79th floor and fall onto the next level down (78th floor) crushing its columns evenly and so on down into the seven levels below the street level. The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds (or even between 16 and 20 seconds to collapse). at nearly free-fall speed. This violates Newton’s Law of Conservation of Momentum that would require that as the stationary inertia of each floor is overcome by being hit, the mass (weight) increases and the free-fall speed decreases. Even if Newton’s Law is ignored, the prevailing theory would have us believe that each of the Twin Towers inexplicably collapsed upon itself crushing all 287 massive columns on each floor while maintaining a (nearly) free-fall speed as if the 100,000, or more, tons of supporting structural-steel framework underneath didn’t exist. Good grief...Good grief what? Do you know how much computering power it would take to do a visual representation of a FEA on the entire structure of the WTC towers during the collapse? I mean good point.But they are not asking for a total collapse model ..also NIST reply seem demonstrate that a global structural collapse model is possible with actual technology. -NIST told NCE this week that it did not believe there is much value in visualising quasi-static processes such as thermal response and load redistribution up to the point of global collapse initiation and has chosen not to develop such visualisations. - But it said it would 'consider' developing visualisations of its global structural collapse model, although its contract with the finite element analysis subcontractor was now terminated.
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Post by PhantomWolf on Mar 6, 2007 1:41:04 GMT -4
If a structural steel building could collapse because of fire (and damage on some steel members), it would do so slowly as the various steel members gradually relinquished their structural strength....
And they did, to a point. Get a stick, hold it in both hands and slowly bend it. It'll slowly deform, until it snaps suddenly.
This is what happened to the columns, first they deform elastically until they pass a point of no return and the deformation is plastic, at which point they fold and fail. Not all of them need to fail at the same time. As each column fails it increases the load on the ones next to it, if they are close to failure as well, then they fail and that load is passed to the next and so on, each time the load increases because there are less columns to take the load and so that the columns fail in a domino affect. In this case that strain was not just from the weight of the building, but from the floor trusses dragging the exterior and central columns towards the interior of the building.
Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity and thus remove their structural strength equally over the entire floor, or floors, in order to cause the top 30-floor building segment (South Tower WTC #2) to drop vertically and evenly onto the supporting 79th floor. The 30 floors from above would then combine with the 79th floor and fall onto the next level down (78th floor) crushing its columns evenly and so on down into the seven levels below the street level.
But this isn't what actually happened. A section of columns gave way and the others were unable to keep the buildings supported so top twisted, and than dropped onto building below destroying the supports below. As the one side fell, the columns on the other side were failing as the load bypassed their load capacity allowing that side to drop as well.
At that point you have a large hammer falling directly onto a very large floor space that wasn't designed to support that sort of dynamic load. With the moving debris of the top of the tower smashing into the floor, it would have placed that entire load onto the truss mounts causing them to buckle and give way, something that was noted in the debris (and lead to original ideas of the truss mounts softening and the floors giving way then.) The outer columns deprived of their support and with debris crashing into them then simply peeled outwards like a banana.
The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds(or even between 16 and 20 seconds to collapse). at nearly free-fall speed. This violates Newton’s Law of Conservation of Momentum that would require that as the stationary inertia of each floor is overcome by being hit, the mass (weight) increases and the free-fall speed decreases.
And with the 16-20 second insert, this no longer causes a problem, the 6-10 seconds is the delay caused by the floors resisting the impact for a very short time. Note that the dynamic loading hitting the floors was far above the resistance of the floors however. Throw a cricket ball at a window and see how much it slows it down..
the prevailing theory would have us believe that each of the Twin Towers inexplicably collapsed upon itself crushing all 287 massive columns on each floor while maintaining a (nearly) free-fall speed as if the 100,000, or more, tons of supporting structural-steel framework underneath didn’t exist.
Again he misses the point. The lower columns were just pushed out of the collapse by the falling debris, they weren't bent and failed. He makes the same mistake as the majority of CTs, that the load was falling onto the columns, it wasn't, it was falling onto the floor whose only supporting structure were four steel mounts, two on the exterior walls, and two on the core. (some actually had two on the exterior and two on other trusses!) The joins in the columns, which were only tack welded and bolted, snapped as the pressure come onto them and they where thrown from the collapse zone as the rumble of the broken concrete, mangled floor trusses and remains of office equipment continued as a pile driver into the next floor crushing drywall, cement, marble, glass fibre ceiling tiles, windows and more into the dust that the compressed air was blasting out from the tower.
If he wants to have a go at looking through the multitude of papers written about the collapse (not just from NIST and FEMA) and then come back with concerns we might take him seriously, but while he's pushing the tired old CT barrow, it's not worth our time.
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Post by feelfree222 on Mar 6, 2007 3:36:07 GMT -4
Again he misses the point. The lower columns were just pushed out of the collapse by the falling debris, they weren't bent and failed. He makes the same mistake as the majority of CTs, that the load was falling onto the columns, it wasn't, it was falling onto the floor whose only supporting structure were four steel mounts, two on the exterior walls, and two on the core. (some actually had two on the exterior and two on other trusses!) The joins in the columns, which were only tack welded and bolted, snapped as the pressure come onto them and they where thrown from the collapse zone as the rumble of the broken concrete, mangled floor trusses and remains of office equipment continued as a pile driver into the next floor crushing drywall, cement, marble, glass fibre ceiling tiles, windows and more into the dust that the compressed air was blasting out from the tower. I was about to give up but it is false to say that the above description was not considered by CT's see 911research.wtc7.net/disinfo/collapse/piledriver.htmlExcerpts The pile-driver theory receded with the ascendency of the truss-failure theory, which abandoned the idea of the entire top sections of the Towers falling as intact blocks. Instead, FEMA told us, the unsupported heights of the freestanding columns, lacking the lateral support of the pancaked floor diaphragms, buckled and collapsed: As the floors collapsed, this left tall freestanding portions of the exterior wall and possibly central core columns. As the unsupported height of these freestanding exterior wall elements increased, they buckled at the bolted column splice connections, and also collapsed. Perimeter walls of the building seem to have peeled off and fallen directly away from the building face, while portions of the core fell in a somewhat random manner. The perimeter walls broke apart at the bolted connections, allowing individual prefabricated units that formed the wall or, in some cases, large assemblies of these units to fall to the street and onto neighboring buildings below. Thus, FEMA never invokes the pile-driver theory, preferring to have us believe that the Towers simply fell apart as a consequence of the alleged floor pancaking. In early 2005, with the release of some of the preliminary reports from NIST's investigation, it became apparent that the pile-driver theory was poised for a come-back. The nearly 300-page Draft of NIST's Final Report on the Twin Towers has only one paragraph describing the start of each Tower's collapse, but the pile-driver theory is unmistakable. The following passage describing the South Tower is almost identical to the one describing the North Tower. The building section above the impact zone began tilting to the south as the columns on the east and west walls rapidly became unable to carry the increased loads. This further increased the gravity loads on the core columns. Once the upper building section began to move downwards, the weakened structure in the impact and fire zone was not able to absorb the tremendous energy of the falling building section and global collapse ensued. Apparently in response to criticisms that the Draft Report "does not actually include the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable", the Final Report added a new section making the pile-driver theory more explicit. It reads, in part: Failure of the south wall in WTC 1 and east wall in WTC2 caused the portion of the building above to tilt in the direction of the failed wall. The tilting was accompanied by a downward movement. The story immediately below the stories in which the columns failed was not able to arrest this initial movement as evidenced by videos from several vantage points. The structure below the level of the collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structures below to absorb that through energy of deformation. 3
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lenbrazil
Saturn
Now there's a man with an open mind - you can feel the breeze from here!
Posts: 1,045
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Post by lenbrazil on Mar 6, 2007 7:56:25 GMT -4
I presume if he were a structural engineer he would have identified himself as such. He claims to have worked on “structural steel buildings” but didn’t say he worked on their structures he could have worked on their duct systems or widows etc. Though he is licensed in Vermont a state with no tall buildings he isn’t licensed in Massachusetts, New York or Pennsylvania so presumably he wasn’t the engineer of record. Just because he claims to have taught “structures lab” at crappy technical school doesn’t make him a structural engineer. www.usnews.com/usnews/edu/college/directory/brief/drglance_3698_brief.php Even if he were a fully accredited structural engineer with experience designing buildings similar to the Trade Center the fact that he seems not to have studied the NIST or ASCE reports themselves but rather drew his information from: - 2 PBS documentaries, the first of which was released BEFORE either “official report” was released and the 2nd a “repackaged” version of the first. So he really based his assessment on one documentary. CT sites …would disqualify him from claiming expert status. He in fact gets numerous points wrong such as (not to mention errors already pointed out): “the prevailing theories as determined by two government agencies, FEMA and NIST”The first report was paid for by FEMA but was carried out by the American Society of Civil Engineers (ASCE) with the support of other engineering associations like the Structural Engineers Association of New York (SEAoNY). “The subsequent 2006 repackaged documentary Building on Ground Zero explained that the connectors held, but that the columns failed, which is also unlikely.”He doesn’t say why this is unlikely. Nuerous engineers better qualified than he who actually studied the collapses disagree. “The prevailing theory for the collapse of the 110-story, award-winning Twin Towers is that when jetliners flew into the 95th and 80th floors of the North and South Towers respectively, they severed several of each building’s columns and weakened other columns with the burning of jet fuel/kerosene (and office combustibles).
However, unlike concrete buildings, structural steel buildings redistribute the stress when several columns are removed and the undamaged structural framework acts as a truss network to bridge over the missing columns.”Actually NIST determined that collapse initiated with truss failure. Load would be redistributed to remaining columns but they then would be subject to greater than normal load, but this that would not be very relevant if collapse initiated with the trusses. “John Skilling, the head structural engineer for the Twin Towers, was asked about an airplane strike. He explained that the Twin Towers were originally designed to withstand the impact of a Boeing 707 (similar in size to the Boeing 767). He went on to say that there would be a horrendous fire from the jet fuel, but “the building structure would still be there.”By most accounts Leslie Robertson was the lead structural engineer of record. Skilling it seems who was his boss came up with the general design while Robertson handled the “nuts and bolts”. Robertson said the study he carried out was for a 707 at approach speed. Roberson said they didn’t study the effects of fire on the structure and if we read Skilling carefully he only mentioned the impact’s effect of the structure and the fire’s impact on the people inside it. The impacts alone are not blamed for the collapses. “The 10,000 gallons of jet fuel (half capacity) in each jetliner did cause horrendous fires over several floors, but it would not cause the steel members to melt or even lose sufficient strength to cause a collapse. This is because the short-duration jet fuel fires and office combustible fires cannot create (or transmit to the steel) temperatures hot enough.”Perhaps he can provide a citation to back this dubious claim if burning building contents alone can not “cause the steel members to…. lose sufficient strength to cause a collapse.” one wonders why fire cites world wide for the last century have required fireproofing of steel or why a pancake collapse was feared in the Meridian Tower fire in Philly or why steel framed builds have collapsed from fire. “If a structural steel building could collapse because of fire, it would do so slowly as the various steel members gradually relinquished their structural strength.”But as he points out as structural members fail they redistribute load to other members. Especially adjoining ones, making them more likely to fail causing a potential domino effect. The structure could be expected to “hold” relatively intact until it no longer could. Saying load is redistributed on one hand and that failure should have been localized on the other is a bit of a contradiction. “However, in the 100-year history of structural-steel framed buildings, there is no evidence of any structural steel framed building having collapsed because of fire.”Incorrect STS60 or someone else provided a link to an article about 3 steel building that collapsed due to a fire. Mr. Rice must be unaware of the ‘Sight and Sound Theater’ and ‘McCormick Place’ fires. www.debunking911.com/firsttime.htm “Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity and thus remove their structural strength equally over the entire floor, or floors.”He once again show his ignorance of the “official theory” which determined that collapse initiated with truss failure. “The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds at nearly free-fall speed.”As already pointed out the collapses took far longer than 10 seconds neither the ASCE or NIST reports cites these times. Professors of structural engineering Barzant and Zhou from Northwestern University and Eduardo Kaussel form MIT (2 of America’s top engineering schools) calculated that the connections on the undamaged floors would have done little to slow the collapses perhaps Mr. Rice can show were they were in error. “This violates Newton’s Law of Conservation of Momentum that would require that as the stationary inertia of each floor is overcome by being hit, the mass (weight) increases and the free-fall speed decreases.”?? As the collapses progressed they gained mass which would make them better able to break floor-column connections. Gravity accelerates at 9.8 m/s/s
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Post by PhantomWolf on Mar 6, 2007 8:01:17 GMT -4
I was about to give up but it is false to say that the above description was not considered by CT's
Note I said the majority of, not all of.
The pile-driver theory receded with the ascendency of the truss-failure theory, which abandoned the idea of the entire top sections of the Towers falling as intact blocks.
The currently theoiry as I understand it doesna't assume an intact "piledriver" after the intial strike, simply the mass of falling debris that was breaking up but still falling a group like if you take a handful of nails and drop them.
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Post by feelfree222 on Mar 6, 2007 16:43:11 GMT -4
The joins in the columns, which were only tack welded and bolted, snapped as the pressure come onto them and they where thrown from the collapse zone as the rumble of the broken concrete, mangled floor trusses and remains of office equipment continued as a pile driver into the next floor crushing drywall, cement, marble, glass fibre ceiling tiles, windows and more into the dust that the compressed air was blasting out from the tower. Remember that the piston like effect was made as a consequence of the intact pile driver theory. I have difficulty believing it is still as powerfull with broken pieces falling on the floor below. It must behave at this point like a broken piston.Right ? Edited spelling
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Post by feelfree222 on Mar 6, 2007 17:07:43 GMT -4
“Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity and thus remove their structural strength equally over the entire floor, or floors.”He once again show his ignorance of the “official theory” which determined that collapse initiated with truss failure. No he his aware of it “The subsequent 2006 repackaged documentary Building on Ground Zero explained that the connectors held, but that the columns failed, which is also unlikely.” He doesn’t say why this is unlikelyMaybe because the journal have shortened the full text, who knows ? www.vermontguardian.com/commentary/032007/TwinTowers.shtml
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Post by feelfree222 on Mar 6, 2007 17:14:58 GMT -4
The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds(or even between 16 and 20 seconds to collapse). at nearly free-fall speed. This violates Newton’s Law of Conservation of Momentum that would require that as the stationary inertia of each floor is overcome by being hit, the mass (weight) increases and the free-fall speed decreases.And with the 16-20 second insert, this no longer causes a problem, the 6-10 seconds is the delay caused by the floors resisting the impact for a very short time. And with the 16-20 second insert, This also demonstrate that the calculated collapse time based on the video you refer is not very precise.
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