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Title: The Destruction of WTC 7
Source:
http://11syyskuu.blogspot.com/2006/02/destruction-of-wtc-7.h
URL Source: http://11syyskuu.blogspot.com/2006/02/destruction-of-wtc-7.html
Published: May 19, 2007
Author: Truthseeker
Post Date: 2007-05-19 06:09:29 by Kamala
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Keywords: 911
Views: 72
Comments: 5
Sunday, February 05, 2006 The Destruction of WTC 7 Latest updates: 5 Sep 06: NIST postpones its report until 2007, will consider if explosions occurred 25 Sep 06: a demolition expert and two structural design professors: WTC 7 was a controlled demolition 13 Dec 06: Heikki Kurttila (DEng): WTC 7 fell as fast as an object falling the same distance through air 1 Jan 07: Frank Legge (Ph.D.): The rate of descent of WTC 7 almost equals gravitational free fall 12 Feb 07: Several witnesses to controlled demolition come forward 4 Mar 07: Structural Engineer William Rice refutes official explanation of WTC collapses World Trade Center 7 was the third skyscraper destroyed on September 11 2001. It was not hit by a plane. The picture on the left shows WTC 7 after the collapse of the Twin Towers. The investigation report on its collapse has been postponed many times. As of this writing (5,5 years after the destruction), it still has not been published. This steel-framed skyscraper, completed in 1987, was located 110 meters (350 feet) away from the closest of the Twin Towers ("WTC 1" on the map below). The building's tenants included the CIA, the Internal Revenue Service, several banks, the Mayor's Office of Emergency Management, and the U.S. Securities & Exchange Commission. A large number of records of ongoing investigations of Enron and other companies were destroyed with WTC 7. No airplane hit WTC 7, but its south facade and southwest corner were damaged by debris ejected from the North Tower, which collapsed at 10.30 am. It was reported on fire at 4.10 pm by CNN, although the fires seem to have started some hours earlier. The fires, whose origin is unknown, appeared on a number of floors, and the building collapsed at 5.20 pm. A high-resolution video of the collapse is available here. The slow-motion video animation below shows the totality and symmetry of the destruction. The Federal Emergency Management Agency, FEMA, speculated that office fires caused the collapse of the building. It, however, acknowledged in its report in May 2002: "The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time. [...] the best hypothesis has only a low probability of occurrence." Later in 2002, Larry Silverstein, the owner of WTC 7, gave in the America Rebuilds TV program a famous "pull it" statement that has commonly been interpreted as meaning that the building was professionally demolished. Did WTC 7 collapse as a result of office fires, or was it demolished with explosives? The answer can be sought by examining the way in which the building collapsed. Collapse Speed As one can observe from the videos of WTC 7's collapse, shortly following the destruction of its penthouse structures, the building fell to the ground in 6.5 seconds. This is a phenomenally short time: a stone dropped from the top of the building would have reached the ground (covering a distance of 174 meters) in 5.95 seconds – if there were no air resistance! However, in principle the distance analyzed should be that from the top of the building to the top of the debris pile, not to the ground. As the exact height of the debris pile is not documented, it is more useful to examine the early stages of the collapse, during which the debris pile does not need to be taken into account. According to the video analysis presented in the 9-11 Eyewitness documentary, starting from the state of rest, WTC 7 fell 100 meters in 4.5 seconds. This results in an acceleration of 9.8 m/s2, corresponding to a free fall. To verify this, I examined the fall of a corner of the building in one collapse video using Blaze Media Pro video editing software. The corner fell 56 meters (=the distance between the Start and End lines in the picture below) in 3.47 seconds. This results in an acceleration of 9.3 m/s2, which corresponds to a very low resistance factor of the structural supports: only 5 percent of the force of gravity of the building's falling upper section. I also measured an acceleration of 8.5 m/s2 for the middle part of the wide facade in the picture, which means that the force of resistance of the structural supports was 13 percent of the force of gravity of the falling upper section (see the calculation in more detail here). My measurements therefore support the conclusion presented in 9-11 Eyewitness that the skyscraper fell virtually unimpeded. The lack of structural resistance seems to be explainable only by the destruction of the structural supports through the use of explosives. WTC 7 dropped rather than collapsed. It came down as if only air had separated the roof of the building from the street below. WTC 7 fell on average 7 floors per second (47 / 6.5). One second after the onset of the collapse, the speed of descent was almost 10 meters/second; after two seconds, almost 20 meters/second; and at the end, about 60 meters/second (over 200 kilometers/hour). According to the analysis of Frank Legge (Ph.D.), the rate of descent of WTC 7 closely matches the rate of gravitational free fall, which – combined with the uniformity of the descent throughout the breadth and length of the building – is irrefutable evidence of controlled demolition. Heikki Kurttila, a Finnish Doctor of Engineering and accident researcher, has made detailed calculations about the collapse speed of WTC 7. He concludes that the short collapse time and low structural resistance "strongly suggest controlled demolition". Kurttila notes that an apple dropped from the height of WTC 7's roof would have taken about 0.5 seconds longer to reach the ground than it took the skyscraper to be completely destroyed. Structural Features of the Collapse A striking feature in the collapse of WTC 7 is symmetry. The collapse progressed evenly throughout the building, and the debris piled up almost entirely within the foundations of the building (see the picture below). The symmetry of WTC 7's descent means that all of its steel supports – 25 central and 58 peripheral columns – were destroyed almost simultaneously. Any asymmetry in the damage to structures would have led to asymmetrical collapse. By contrast, a fully symmetrical collapse without controlled use of explosives would not have followed the principle of least resistance. Local fires and structural damage here and there could not have weakened all the central and peripheral support structures in a way that would have caused all of them to give in at the same moment. The simultaneity of the destruction of support structures throughout the building can, however, be explained by controlled demolition. A controlled demolition is also suggested by the drop of the center of the skyscraper moments before the surrounding structures started to fall, as well as by the fact that the outer walls were pulled inwards. In a controlled demolition the collapse is caused by first destroying the weight-carrying core of a building, which "pulls" the exterior walls inwards ("implosion"). Although the lowest floor with fires was reportedly the sixth floor, the building seems to have undergone a traditional demolition, beginning from the bottom floor. An emergency worker who witnessed the collapse of WTC 7 was interviewed on 9/11. He described hearing what sounded like a "clap of thunder", followed by what looked like "a shockwave ripping through the building", with windows busting out, and "about a second later the bottom floor caved out and the [rest of] the building followed after that". The videos showing the collapse support his description. At least one high-resolution video of the collapse of WTC 7 clearly shows one more characteristic of controlled demolition: streamers of dust emerging out of the building. A Dutch demolition expert Danny Jowenko (right), who owns a demolition company and has been in the business for almost 30 years, concluded in September 2006 that WTC 7 "is controlled demolition. [...] A team of experts did this. This is professional work, without any doubt." Hugo Bachmann, a Swiss professor emeritus for structural design and construction, said in Tages-Anzeiger : "In my opinion WTC 7 was with great probability brought down by controlled demolition done by experts". In addition, Jörg Schneider, another Swiss Professor emeritus for structural design and construction, interprets the existing videos as indices that "WTC 7 was with great probability brought down by explosives". Fire Endurance of Steel Steel is very fire-resistant material. In tests conducted by Chorus Construction in several countries, the fire endurance of steel-framed parking garages was examined by feeding fires with hydrocarbon fuel. Steel beams and pillars heated to a maximum of 360 degrees Celsius, and the breaking of steel was not even close. In Cardington fire endurance tests, modelled on conditions in real buildings, unprotected steel was subjected to temperatures of up to 1100 degrees Celsius (2012 F), but there was no collapse. In the Windsor Building in Madrid, an almost 24-hour intensive fire did not collapse the building. Moreover, the fires in WTC 7 were insignificant compared to fires in Windsor Building and all other skyscraper fires. The latest case is the all-engulfing fire in Al Nasr Tower in 2006. Fires have never collapsed a single steel-framed highrise to the ground. In the picture of WTC 7 to the right, the fires are limited to small areas, almost all windows are intact, and no red heat indicative of temperatures capable of softening steel is visible. The situation is the same in other photographs taken of the building in late afternoon. In this video a fair amount of smoke, but no flames, can be seen. By contrast, WTC 5, which was badly damaged by the collapse of the North Tower next to it, burned very powerfully: its floors were covered by a sea of flames and all windows were broken. However, this building, despite the fact that it had weaker support structures than WTC 7, did not collapse into a debris pile, but remained standing. Characteristics of the Debris The debris of WTC 7 was extremely hot weeks after the collapse of the building. Thermal imaging by NASA showed that the top of the debris pile had a temperature of 730 degrees Celsius five days after the collapse. Deeper, and immediately after the destruction, temperatures were probably considerably higher. Residual temperatures like this cannot be explained by office fires or by an ordinary, gravity-driven collapse. When the potential energy of a building experiencing an ordinary gravitational collapse turns into thermal energy, the result is only a few degrees' average increase in temperature. According to several reports, molten metal (also suggested by this video footage) was found under the debris pile of WTC buildings. To melt structural steel, temperatures exceeding 1500 degrees Celsius are required. Such temperatures are never achieved in office fires. In addition to molten metal, partly evaporated steel beams were found in the debris of WTC 7. As professor Jonathan Barnett pointed out in a New York Times interview, the fires in the building could not have produced temperatures capable of evaporating steel. However, the use of explosives like thermite can produce temperatures (even 3000 degrees Celsius) that can melt and even evaporate steel. FEMA's investigators were not allowed to work in the collapse zone itself. They were allowed to examine the debris of WTC skyscrapers only in landfill areas used as temporary storage for the steel debris before its recycling. By May 2005, when FEMA finished its preliminary report calling for further investigation, all the steel debris had been sold and shipped into the Far East. Only 156 pieces of steel were chosen for futher analysis, of which a ridiculous total of 4 were from WTC 7. Even these no longer seem to exist. As WTC 7 was evacuated over six hours before its destruction, there were no grounds for the rapid removal and recycling of the steel debris. Quite the contrary: as WTC 7 was one of the three greatest building collapses in recorded history (the other two being the North and South Towers), the debris of the building should have been meticulously examined. Many individuals and publications, such as the Fire Engineering Magazine, protested strongly against the rapid destruction of the evidence. Witness statements Craig Bartmer, a NYPD officer, states that he saw WTC 7 come down and heard a number of explosions in rapid succession. He is convinced that the skyscraper was brought down with explosives. Several rescue personnel have also come forward saying they were told that the building would be brought down by means of explosives. The above-cited testimony about the shockwave and the lowest floors collapsing first supports controlled demolition. Interestingly, a news report on a Finnish TV channel on September 12, 2001, stated that the authorities brought Building 7 down with explosives due to the apparent danger of collapse. Final Words Was WTC 7 destroyed as a result of controlled demolition? Everyone can draw their own conclusions from the way in which the building was destroyed and the temperatures produced in the destruction. If and when the building was demolished, it must have been wired with explosives before September 11th. An operation of that magnitude could not have been accomplished during a couple of chaotic hours. This is why the official hypotheses have not touched on the most obvious explanation for the collapse of the skyscraper. It is revealing that the 9/11 Commission, which published its report in 2004, does not mention in a single sentence the destruction of the third skyscraper resulting from the terrorist attack in New York. FEMA's work has been continued by the National Institute of Standards and Technology, which has again postponed its report on WTC 7, this time until 2007. NIST is now saying that it is also investigating the hypothesis that explosions initiated the collapse. Interviewed in the March 2006 issue of New York Magazine, Dr S. Shyam Sunder, NIST lead investigator, summed up the present state of the investigation: NIST did have "some preliminary hypotheses" on 7 WTC, Dr. Sunder said. "We are studying the horizontal movement east to west, internal to the structure, on the fifth to seventh floors." Then Dr. Sunder paused. "But truthfully, I don't really know. We've had trouble getting a handle on Building No. 7." Send email Posted by Truthseeker at 9:10 AM
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#1. To: Kamala (#0)
A new name with a simple explanation, very good.
"Guard against the impostures of pretended patriotism." ~George Washington
So Mark continues his role of being the straight man for discrediting the *truth* movement by posting articles in which it is easy to prove multiple lies. Kurttila is quoted on the web saying "The observed collapse time of WTC 7 was 6.5 seconds. That is only half a second longer than it would have taken for the top of the building to fall to the ground in a vacuum, and half a second shorter than the falling time of an apple when air resistance is taken into account." In the above Kurtilla completely ignores the fact that video taken that day clearly show the east mechanical penthouse on top the building sinking into the building more than 6 seconds before the collapse timed at 6.5 seconds even began. Now why would he ignore something as significant as that, folks? Frank wrote a paper that in his words "examines the rate of descent of WTC 7 using measurements of a video that shows the top half of the building. And again ignores what happened to the east mechanical penthouse more than 6 seconds before the start of the video he used? Is there something about that east mechanical penthouse collapse that the *truth* movement doesn't want you to know, folks? One might begin to suspect that. ROTFLOL! William Rice claims the WTC towers collapsed in 10 seconds when video clearly proves it took 15 seconds. Here is a challenge for you folks. Mr Rice claims to be structural engineer. Says he worked at the Vermont Technical College. But I don't see his name mentioned anywhere on their website. Nor can I find anything else about him. Like his education. Where he actually did work. What type of work he did. He makes a lot of claims that give one good reason to doubt he really is/was a structural engineer. For example, he makes this absolutely ludicrous statement "Newton’s Law is immaterial when compared to the resistance provided by the massive supporting structural steel framework of each Tower." This is a lie. **************** From http://www.debunking911.com/pull.htm Now here is what the WTC 7 debris pile looked like: Eerily, the north face is on the debris pile as if a shroud were laid gently over the dead building. It fell over after the majority of the building fell. This indicates that the south side of the building fell before the north. It's almost as if the buildings last words were "[This] did it!..". And now comes the most important and telling fact in this photo. Note the west side (Right side in this photo) of the north face is pointing toward the east side (Left side of this photo) where the penthouse was. What caused this? It would not be unreasonable to expect the building to fall toward the path of least resistance. The path of least resistance in this case would be the hole in the back of the building and the hole left by the penthouse. Since the penthouse was on the east and the 20 story hole in the middle, that would make the east and middle the path of least resistance. The conspiracy sites agree with this theory but say it never happened. They say the fact that it didn't happen helps prove controlled demolition. But you see it happen here... What will they say now? "But the building doesn't look like it fell over, it fell "in its own foot print" you might say. That's because it is impossible for a 47 story steel building to fall over like that. It's not a small steel reinforced concrete building like the ones shown as *Examples* of buildings which fell over. Building 7 is more like the towers, made up of many pieces put together. It's not so much a solid block as those steel reinforced concrete buildings. This evidence supports the NIST contention that the building collapse progressed from the penthouse out as columns were weakened by the fires. The slow sinking of the penthouses, indicating the internal collapse of the building behind the visible north wall, took 8.2 seconds according to a NIST preliminary report. Seismograph trace of the collapse of WTC 7 indicates that parts of the building were hitting the ground for 18 seconds. This means the collapse took at least 18 seconds, of which only the last approximately 15 seconds are visible in videos: 8 seconds for the penthouses and 7 seconds for the north wall to come down. ... snip ... To put it simply, the building DID fall over backward and to the south-east. Just not like a steel reinforced concrete building would. Another telling photo is this one taken closer to the event date Note just past building 7 is a small amount of debris on the white building behind it. (Building 7 is pile in the upper center-left of the photo. The white building is at the top center-left of the photo.) That building is to the north east corner of building 7. Note about 1/3rd of the east side of the building falling to the north in the photo below. Here is another photo from over Building 7. The white building is on the left. Note the debris from building 7 which crossed the street and landed on top of the white building. ************* What Jowenko wasn't told before he said that, however, is that WTC 7 was on fire for hours, that firemen has observed the structure leaning well before the collapse and had said they thought it would collapse, that there was huge gaping hole on the south side of the structure, that the east penthouse collapsed into the structure more than 6 seconds before the video he was shown began, and that the structure toppled to the south (as noted in the material I posted above). Also not mentioned is the fact that Jowenko does NOT believe WTC 1 or WTC 2 looked like demolitions and his theory for WTC 7 is that Silverstein decided to bring it down AFTER the collapse of the towers rather than try to repair it. Both of these were shown the same limited video material and not told all the rest, just like Jowenko. And again, these two have not made any statements about WTC 1 or WTC 2 being controlled demolitions. But isn't that an essential part of the *truther* belief system? This is a very deceptive description of the Cardington tests and results. This is deceptive as well. But much easier to prove so I will do it to show you what I mean by Mark wanting to discredit the Truth Movement. The fact is that ALL portions of the Windsor Tower that relied solely on a steel frame did collapse during that fire. ALL portions of the tower that relied on a reinforced concrete frame did not collapse. Just look at this to see I'm right: http://www.concretecentre.com/main.asp?page=1095 Never mind that the 24 story building burned only about an hour and the fire was fought by firefighters the whole time. Never mind that it didn't suffer any damage before the fire. Never mind that it was under construction and didn't have much to burn inside it. Even ignoring that there were fires burning in the rubble after the collapse and no real experts in such things as fire and steel have come forward to say those fires were incapable of becoming hot enough to produce molten metal, the potential energy in skyscapers is enormous. Physicists have done calculations showing the potential energy in the WTC towers was about percent of that in the Hiroshima bomb. To suggest that amount of energy confined to a fairly small region wouldn't raise the temperature only a few degrees borders on silly. This certainly is deceptive. The reader might think from the above that professor Barnett believes thermite is what caused the molten metal and "evaporating" steel. He did no such thing and is in fact definitely NOT a proponent of that silly theory. This is absolutely false. There are many pictures of engineers examining the steel members and other debris at the collapse site. Wwhy can't members of the truth movement see things that are OBVIOUS in photos? It's like they have some sort of "truth" filter on ... one that keeps the truth OUT. This is also completely false. Just thought I'd point that out ... like I have a dozen times before. But I won't bother repeating the proof its false because I wouldn't want christine to say I was spamming the forum with that material. ROTFLOL! This is false too. There are statements from the fire chief and others that they were still inside WTC 7 between 12:30 and 2 pm ... less than 6 hours before it's collapse. But not because they thought the structure was a demolition. They had other reasons. You *Truthers* always leave that part of the story out. Don't get taken in by the deception of "Truthseeker" and Kamala, folks. Get the real picture of what happened: http://www.debunking911.com/WTC7.htm http://www.911myths.com/WTC7_Lies.pdf --------------------------------------------------------- Aren't you lucky. You get to receive one of the 15 posts I'm allowed each day.
Symmetry "Guard against the impostures of pretended patriotism." ~George Washington
http://video.google.com/videoplay?docid=-999558027849894376&q=9%2F11&hl=en http://video.google.com/videoplay?docid=4026073566596731782&q=9%2F11+demolition&hl=en
"Guard against the impostures of pretended patriotism." ~George Washington
: Because BeAChooser has been shown to repeatedly post spam and falsehoods, continued substantive response to his posts, including this one, is considered a waste of time. This NOTICE is the standard response to all BAC blather.
Heikki Kurttila, a Finnish Doctor of Engineering and accident researcher, has made detailed calculations about the collapse speed of WTC 7. He concludes that the short collapse time and low structural resistance "strongly suggest controlled demolition". Kurttila notes that an apple dropped from the height of WTC 7's roof would have taken about 0.5 seconds longer to reach the ground than it took the skyscraper to be completely destroyed.
#2. To: Kamala, all (#0)
Heikki Kurttila (DEng): WTC 7 fell as fast as an object falling the same distance through air
Frank Legge (Ph.D.): The rate of descent of WTC 7 almost equals gravitational free fall
Structural Engineer William Rice refutes official explanation of WTC collapses
A striking feature in the collapse of WTC 7 is symmetry. The collapse progressed evenly throughout the building, and the debris piled up almost entirely within the foundations of the building (see the picture below).
A Dutch demolition expert Danny Jowenko (right), who owns a demolition company and has been in the business for almost 30 years, concluded in September 2006 that WTC 7 "is controlled demolition. [...] A team of experts did this. This is professional work, without any doubt."
Hugo Bachmann, a Swiss professor emeritus for structural design and construction, said in Tages-Anzeiger : "In my opinion WTC 7 was with great probability brought down by controlled demolition done by experts". In addition, Jörg Schneider, another Swiss Professor emeritus for structural design and construction, interprets the existing videos as indices that "WTC 7 was with great probability brought down by explosives".
In Cardington fire endurance tests, modelled on conditions in real buildings, unprotected steel was subjected to temperatures of up to 1100 degrees Celsius (2012 F), but there was no collapse.
In the Windsor Building in Madrid, an almost 24-hour intensive fire did not collapse the building.
The latest case is the all-engulfing fire in Al Nasr Tower in 2006.
In the picture of WTC 7 to the right, the fires are limited to small areas, almost all windows are intact, and no red heat indicative of temperatures capable of softening steel is visible. The situation is the same in other photographs taken of the building in late afternoon.
WTC 7 fire 2 hours before collapse When the potential energy of a building experiencing an ordinary gravitational collapse turns into thermal energy, the result is only a few degrees' average increase in temperature.
In addition to molten metal, partly evaporated steel beams were found in the debris of WTC 7. As professor Jonathan Barnett pointed out in a New York Times interview, the fires in the building could not have produced temperatures capable of evaporating steel. However, the use of explosives like thermite can produce temperatures (even 3000 degrees Celsius) that can melt and even evaporate steel.
FEMA's investigators were not allowed to work in the collapse zone itself. They were allowed to examine the debris of WTC skyscrapers only in landfill areas used as temporary storage for the steel debris before its recycling.
Only 156 pieces of steel were chosen for futher analysis, of which a ridiculous total of 4 were from WTC 7. Even these no longer seem to exist.
As WTC 7 was evacuated over six hours before its destruction,
Many individuals and publications, such as the Fire Engineering Magazine, protested strongly against the rapid destruction of the evidence.
#3. To: Kamala (#0)
The Demolition-Like Symmetry of the Twin Towers' Falls
#4. To: All (#3)
#5. To: BeAChooser (#2)
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