chrismohr
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Part 15 Free Fall Collapse of Building 7
Hi all,
I think I will rearrange this rebuttal to be at the end, because it has a good rhetorical flourish at its conclusion. This is my first attempt to attach a picture too; see if it works.
Chris Mohr
Slide: The Best Explanation I Know for the Natural Free-fall Collapse of Building 7
Face: We are now at part 15 of our respectful rebuttal of Richard Gage’s 911 video Blueprint for Truth. Here we will investigate one of Richard’s central claims, that the freefall collapse of part of the north face of Building 7 is the silvber bullet which proves controlled demolition beyond a reasonable doubt. At the very beginning of the debate, Richard Gage said, "My opponent must resolve the symmetrical, free-fall collapse of Building 7, or the debate is over.” Let’s go over it in more detail, because it is of central importance to the controlled demolition theory.
It was also important to me that I understand this, because common sense told me that a building can’t collapse at “gravitational acceleration” unless all resistance has been removed from below the collapsing structure. Remember, I had already asserted that the Twin Towers probably collapsed at around 2/3 of freefall acceleration, and used that as evidence that there was structural resistance to the collapse. It is not a mystery a building collapsed after burning all day, no water, no fire fighting. But even so, how could it be at freefall? NIST’s answer to my question was incomplete, so I looked for explanations directly from experts in the field: structural engineers, physicicts, and others.
Three buildings collapsed on 911. Each of the Twin Towers was 110 stories high and they never exceeded about 2/3 of free-fall acceleration. Building 7 was 47 stories high and only one perimeter of 8 of those stories is known to have collapsed at freefall acceleration. So on that day, a total of 267 floors collapsed and one face of eight of those floors fell at freefall. Engineers I talked to say that is insignificant, but I kept focusing on it because I really wanted an answer.
When looking at the acceleration curve of that perimeter wall, I also noticed that for over a second of those 2.25 seconds, the collapse was very slightly faster than freefall, maybe 1/10 of 1%. That is such a tiny fraction that it could well have been with in the margin of error of the measuring process, but because the measurements consistently showed slightly faster than freefall for over a second, another possibility is that we are actually looking at faster than freefall collapse of this one wall. The hypothesis I am presenting here explains even this possibility.
Free-fall acceleration does not mean no resistance. It means no net resistance, meaning resistance can be canceled out by other forces. For 259 total floors in the three buildings, we witnessed substantial net positive resistance to the collapses and therefore much less than freefall acceleration. . For one wall of those other eight floors of Building 7, we may have had negative net resistance with very slightly faster than freefall acceleration. Freefall does not mean controlled demolition; the Southwark Towers demolition for example, took 7.4 seconds, not 4.5 freefall seconds. That’s because in controlled demolition they often don’t use enough explosives to eliminate all resistance. Often you’ll see near-freefall acceleration at the beginning of a controlled demolition, then less than freefall acceleration as they rely more on gravity to do the rest of the work. Building 7 started at much less than freefall, then briefly equalled or exceeded freefall for much of eight stories on one wall, then quickly went to less than freefall in the end. This would have required less than the usual amount of explosives to start the collapse, then way more explosives to bring it up to freefall in the middle, then fewer or no explosives again near the end. As controlled demolition advocate David Chandler explained to me, “Building 7 was overkill.”
By contrast, NIST’s freefall model “showed the exterior columns buckling and losing their capacity to support the loads from the structure above.”
Building 7's structural integrity deteriorated as it burned, and firefighters feared a collapse. firefighter Miller video: fire can cause structural degradation and, yes, collapse of a steel-framed skyscraper. Mike Catalano was in the building during the fire. He said the fire was large enough to make it collapse.
NIST did several simulations of the Building 7 collapse, adding and removing variables to see which simulation could have caused the collapse. The long duration of the multiple floor fires was the primary cause of the collapse. The simulation with fire-induced damage but no debris damage identified the same initiating event and also led to global collapse of the building, further indicating that the debris impact damage was not a principal contributor to the collapse.
WTC7 was prone to classic progressive collapse in the absence of debris impact and fire-induced damage when a section of Column 79 between Floors 11 and 13 was removed. The collapse sequence demonstrated a vertical and horizontal progression of failure upon the removal of the Column 79 section, followed by buckling of exterior columns, which led to the collapse of the entire building.
The building did fall in several different scenarios, with trial and error they discovered a critical flaw bearing in the approximated columns. The damage was done and the building was deteriorating, where portions continued to give away which in turn produced an onset of collapse, which in turn caused an onset of global collapse.... as it did in different models with different kinds of trauma, all showing the weakness of the building to be a victim of progressive collapse.
So here’s how the very fast Building 7 collapse could have happened naturally:
STICK DEMO Imagine this stick is a column. Pushing down, it kinks a tiny bit at first, then it breaks, as many columns did. The columns were all interconnected so the load was shared.
NIST DIAGRAM OF COLLAPSE ACCELERATION SLIDE.
Number 1.) In stage 1, the final perimeter collapse started almost imperceptibly, like the stick barely bending, much slower than freefall. Classic controlled demolitions start at closer to freefall acceleration to maximize the kinetic energy. But in stage one of this graph, acceleration increased gradually as net resistance gradually fell away, until in stage two it attained perhaps very slightly faster than freefall, one on wall for only eight stories out of 47. Acceleration rates bump around a bit with many of the dots consistently above the freefall curve, for eight stories. In the final seconds of the collapse it slowed down. If this were a controlled demolition, why would the acceleration rate have been so different in these three phases and even maybe slightly exceeded freefall?
Number 2.) New Collapse video The east penthouse collapsed. You can see sunlight shining (Time video clip so sunshine light happens here) through the upper left windows, and more windows breaking along the left side as the penthouse collapsed to the ground. This was an asymmetrical interior collapse, not a symmetrical controlled demolition. For 7 or 8 seconds the interior caved in on itself, much as described by NIST with possible variations on the NIST hypothesis as offered by the Council on Tall Buildings and Urban Habitat and others. Remember, the initial internal collapse sequence was invisible to us.
Number 3.) SLIDE OF MY DIAGRAM. Debris fell inside the center of the building and down, shifting all the load to the perimeter columns over those eight seconds.
Number 4. ) The debris pile spread out at the bottom and pushed out against columns randomly, stressing the columns with irregular horizontal loads.
Number 5 at the top.) (Kink) The columns, unevenly weakened from seven hours of fires, were also pulled in from the breaking support beams above. The small kink along the top of the building was evidence of columns about to snap.
Number 6
The perimeter columns buckled, pushing their loads to other columns at the speed of sound, triggering more column breaks at the weaker welded connections, causing gradually increasing acceleration as structural resistance in the perimeter columns quickly gave way one by one.
This begins stage two of the perimeter collapse. Acceleration may have slightly exceeded 100% of free fall for much of these eight stories. How?
Number 7): An 8-story chunk of floors held onto a perimeter wall. Those attached floors literally torqued the perimeter wall down those eight stories. David Chandler told me that this would have no effect on the net collapse speed. “Think of the falling chunk of building as a "system". Put a dotted line around it as the boundary of the system. Anything going on within the system (such as any torquing) have no effect on the motion of the system as a whole.” But that boundary is artificial. Others hypothesize that the falling building core pulled the perimeter down via the floor trusses and are treating the facade only as the "system" whose center of mass fell at g, or even slightly faster for moments. The torque experienced by that system would thus be external to the system in question. The building twisted down with a 6 degree tilt.
(See design, number 8) Number 8): Those collapsing beams still clinging to the walls functioned as levers. If the left end of the beam is held in place or even slowed down in its fall, the left side becomes the pivot for the lever. If the right side is still grabbing onto the wall and some kind of weight is also yanking the beam down, that weight is leveraged, and the lever throws the facade down at faster than freefall acceleration.
Number 9.) This leveraged pull down overwhelmed any remaining resistance and resulted in less than net-zero resistance and a barely faster than free-fall drop.
Number 10.) As the perimeter crashed into the debris pile, its descent was slowed. This is the third stage of the collapse sequence.
Controlled demolition cannot explain possible greater than free-fall acceleration, and buildings being brought down by controlled demolition usually collapse at slower than free-fall. Leveraging and torquing by attached beams does explain it. Richard, on the other hand, asserts that noisy explosive nanothermites were used to bring down the Twin Towers and quieter Thermate for Building 7. Thermate “cuts through steel like a hot knife through butter,” but much too slowly for Precise demolition! And if thermates were used on the outside columns, there would be hundreds of blinding lights through the windows with no dust to block the view. Even if the light were shielded at first, thermate would continue to burn bright for at least thirty seconds more, well past and through the entire collapse sequence, when masking the light sources would be impossible.
I’ve now explained all of the major anomalies Richard demanded I account for. I have also given over a hundred reasons why the controlled demolition theory is contradicted by the facts, and most of them Richard has not answered at all.
Mr. Gage has failed to meet his burden of proof, which is on anyone who makes such an extraordinary claim. Instead, he used reverse scientific method, digging up anomalies and demanding that I prove they’re not caused by controlled demolition. I fought this debate the hard way by clearly answering them; now you, the viewer, have some good information. I respectfully submit that the weight of the evidence overwhelmingly favors natural collapse. Richard, the debate is over. Thank you all for watching.
Hi all,
I think I will rearrange this rebuttal to be at the end, because it has a good rhetorical flourish at its conclusion. This is my first attempt to attach a picture too; see if it works.
Chris Mohr
Slide: The Best Explanation I Know for the Natural Free-fall Collapse of Building 7
Face: We are now at part 15 of our respectful rebuttal of Richard Gage’s 911 video Blueprint for Truth. Here we will investigate one of Richard’s central claims, that the freefall collapse of part of the north face of Building 7 is the silvber bullet which proves controlled demolition beyond a reasonable doubt. At the very beginning of the debate, Richard Gage said, "My opponent must resolve the symmetrical, free-fall collapse of Building 7, or the debate is over.” Let’s go over it in more detail, because it is of central importance to the controlled demolition theory.
It was also important to me that I understand this, because common sense told me that a building can’t collapse at “gravitational acceleration” unless all resistance has been removed from below the collapsing structure. Remember, I had already asserted that the Twin Towers probably collapsed at around 2/3 of freefall acceleration, and used that as evidence that there was structural resistance to the collapse. It is not a mystery a building collapsed after burning all day, no water, no fire fighting. But even so, how could it be at freefall? NIST’s answer to my question was incomplete, so I looked for explanations directly from experts in the field: structural engineers, physicicts, and others.
Three buildings collapsed on 911. Each of the Twin Towers was 110 stories high and they never exceeded about 2/3 of free-fall acceleration. Building 7 was 47 stories high and only one perimeter of 8 of those stories is known to have collapsed at freefall acceleration. So on that day, a total of 267 floors collapsed and one face of eight of those floors fell at freefall. Engineers I talked to say that is insignificant, but I kept focusing on it because I really wanted an answer.
When looking at the acceleration curve of that perimeter wall, I also noticed that for over a second of those 2.25 seconds, the collapse was very slightly faster than freefall, maybe 1/10 of 1%. That is such a tiny fraction that it could well have been with in the margin of error of the measuring process, but because the measurements consistently showed slightly faster than freefall for over a second, another possibility is that we are actually looking at faster than freefall collapse of this one wall. The hypothesis I am presenting here explains even this possibility.
Free-fall acceleration does not mean no resistance. It means no net resistance, meaning resistance can be canceled out by other forces. For 259 total floors in the three buildings, we witnessed substantial net positive resistance to the collapses and therefore much less than freefall acceleration. . For one wall of those other eight floors of Building 7, we may have had negative net resistance with very slightly faster than freefall acceleration. Freefall does not mean controlled demolition; the Southwark Towers demolition for example, took 7.4 seconds, not 4.5 freefall seconds. That’s because in controlled demolition they often don’t use enough explosives to eliminate all resistance. Often you’ll see near-freefall acceleration at the beginning of a controlled demolition, then less than freefall acceleration as they rely more on gravity to do the rest of the work. Building 7 started at much less than freefall, then briefly equalled or exceeded freefall for much of eight stories on one wall, then quickly went to less than freefall in the end. This would have required less than the usual amount of explosives to start the collapse, then way more explosives to bring it up to freefall in the middle, then fewer or no explosives again near the end. As controlled demolition advocate David Chandler explained to me, “Building 7 was overkill.”
By contrast, NIST’s freefall model “showed the exterior columns buckling and losing their capacity to support the loads from the structure above.”
Building 7's structural integrity deteriorated as it burned, and firefighters feared a collapse. firefighter Miller video: fire can cause structural degradation and, yes, collapse of a steel-framed skyscraper. Mike Catalano was in the building during the fire. He said the fire was large enough to make it collapse.
NIST did several simulations of the Building 7 collapse, adding and removing variables to see which simulation could have caused the collapse. The long duration of the multiple floor fires was the primary cause of the collapse. The simulation with fire-induced damage but no debris damage identified the same initiating event and also led to global collapse of the building, further indicating that the debris impact damage was not a principal contributor to the collapse.
WTC7 was prone to classic progressive collapse in the absence of debris impact and fire-induced damage when a section of Column 79 between Floors 11 and 13 was removed. The collapse sequence demonstrated a vertical and horizontal progression of failure upon the removal of the Column 79 section, followed by buckling of exterior columns, which led to the collapse of the entire building.
The building did fall in several different scenarios, with trial and error they discovered a critical flaw bearing in the approximated columns. The damage was done and the building was deteriorating, where portions continued to give away which in turn produced an onset of collapse, which in turn caused an onset of global collapse.... as it did in different models with different kinds of trauma, all showing the weakness of the building to be a victim of progressive collapse.
So here’s how the very fast Building 7 collapse could have happened naturally:
STICK DEMO Imagine this stick is a column. Pushing down, it kinks a tiny bit at first, then it breaks, as many columns did. The columns were all interconnected so the load was shared.
NIST DIAGRAM OF COLLAPSE ACCELERATION SLIDE.
Number 1.) In stage 1, the final perimeter collapse started almost imperceptibly, like the stick barely bending, much slower than freefall. Classic controlled demolitions start at closer to freefall acceleration to maximize the kinetic energy. But in stage one of this graph, acceleration increased gradually as net resistance gradually fell away, until in stage two it attained perhaps very slightly faster than freefall, one on wall for only eight stories out of 47. Acceleration rates bump around a bit with many of the dots consistently above the freefall curve, for eight stories. In the final seconds of the collapse it slowed down. If this were a controlled demolition, why would the acceleration rate have been so different in these three phases and even maybe slightly exceeded freefall?
Number 2.) New Collapse video The east penthouse collapsed. You can see sunlight shining (Time video clip so sunshine light happens here) through the upper left windows, and more windows breaking along the left side as the penthouse collapsed to the ground. This was an asymmetrical interior collapse, not a symmetrical controlled demolition. For 7 or 8 seconds the interior caved in on itself, much as described by NIST with possible variations on the NIST hypothesis as offered by the Council on Tall Buildings and Urban Habitat and others. Remember, the initial internal collapse sequence was invisible to us.
Number 3.) SLIDE OF MY DIAGRAM. Debris fell inside the center of the building and down, shifting all the load to the perimeter columns over those eight seconds.
Number 4. ) The debris pile spread out at the bottom and pushed out against columns randomly, stressing the columns with irregular horizontal loads.
Number 5 at the top.) (Kink) The columns, unevenly weakened from seven hours of fires, were also pulled in from the breaking support beams above. The small kink along the top of the building was evidence of columns about to snap.
Number 6
The perimeter columns buckled, pushing their loads to other columns at the speed of sound, triggering more column breaks at the weaker welded connections, causing gradually increasing acceleration as structural resistance in the perimeter columns quickly gave way one by one. This begins stage two of the perimeter collapse. Acceleration may have slightly exceeded 100% of free fall for much of these eight stories. How?
Number 7): An 8-story chunk of floors held onto a perimeter wall. Those attached floors literally torqued the perimeter wall down those eight stories. David Chandler told me that this would have no effect on the net collapse speed. “Think of the falling chunk of building as a "system". Put a dotted line around it as the boundary of the system. Anything going on within the system (such as any torquing) have no effect on the motion of the system as a whole.” But that boundary is artificial. Others hypothesize that the falling building core pulled the perimeter down via the floor trusses and are treating the facade only as the "system" whose center of mass fell at g, or even slightly faster for moments. The torque experienced by that system would thus be external to the system in question. The building twisted down with a 6 degree tilt.
(See design, number 8) Number 8): Those collapsing beams still clinging to the walls functioned as levers. If the left end of the beam is held in place or even slowed down in its fall, the left side becomes the pivot for the lever. If the right side is still grabbing onto the wall and some kind of weight is also yanking the beam down, that weight is leveraged, and the lever throws the facade down at faster than freefall acceleration.
Number 9.) This leveraged pull down overwhelmed any remaining resistance and resulted in less than net-zero resistance and a barely faster than free-fall drop.
Number 10.) As the perimeter crashed into the debris pile, its descent was slowed. This is the third stage of the collapse sequence.
Controlled demolition cannot explain possible greater than free-fall acceleration, and buildings being brought down by controlled demolition usually collapse at slower than free-fall. Leveraging and torquing by attached beams does explain it. Richard, on the other hand, asserts that noisy explosive nanothermites were used to bring down the Twin Towers and quieter Thermate for Building 7. Thermate “cuts through steel like a hot knife through butter,” but much too slowly for Precise demolition! And if thermates were used on the outside columns, there would be hundreds of blinding lights through the windows with no dust to block the view. Even if the light were shielded at first, thermate would continue to burn bright for at least thirty seconds more, well past and through the entire collapse sequence, when masking the light sources would be impossible.
I’ve now explained all of the major anomalies Richard demanded I account for. I have also given over a hundred reasons why the controlled demolition theory is contradicted by the facts, and most of them Richard has not answered at all.
Mr. Gage has failed to meet his burden of proof, which is on anyone who makes such an extraordinary claim. Instead, he used reverse scientific method, digging up anomalies and demanding that I prove they’re not caused by controlled demolition. I fought this debate the hard way by clearly answering them; now you, the viewer, have some good information. I respectfully submit that the weight of the evidence overwhelmingly favors natural collapse. Richard, the debate is over. Thank you all for watching.
How can you say that with a straight face? 
