It may be more complex... but what sort of force would be required to break it free from the facade... essentially the same sort of lateral force that "Brownian motion" would supply? Would it fall much closer to 1WTC and not "sail" the 430 feet to the World Financial center?It is not speculation that it takes high explosives upwards of 100 kg to hurl a single wall panel all the way to the WFC, just to satisfy Conservation of momentum. @Christopher 7 studiously avoids that demonstrated fact. He needs to get serious about his hypothesis.
A large section, peeling away from WTC 1 would remain in tact because once it is falling over there are no forces acting upon it to break a smaller section away. The collapse zone was already past the large section as it peeled away so there was nothing to fall on it and break a single section away....
I completely agree.If the pivot is on the ground, the tallest parts of the object (whether a chimney or a skyscraper) would need to move faster to stay in line with the lower parts, and if their inertia is greater than the cohesion of the parts, they will break away.
The sideways load-bearing required the floor panels being tied into the core. It was a "framed tube" system.It'd be interesting to know how much of that kind of sideways load bearing capacity was designed into the WTC facade.
And in the context of this thread, it's well worth remembering the relative fragility of the connections holding this whole system together.
There were four major structural subsystems in the towers: the exterior wall, the core, the
floor system, and the hat truss. The structural design team incorporated a framed-tube concept
for the exterior structural system. Columns supporting the building were located both along the
external faces and within the core. The core also contained the elevators, stairwells, and utility shafts. The dense array of columns along the building perimeter resisted lateral wind loads, while also supporting the gravity loads about equally with the core columns. The floor system provided stiffness and stability to the framed-tube system in addition to supporting the floor loads.
...
In the framed-tube concept, the exterior frame system resists the force of the wind. The exterior columns carry a portion of the building gravity loads, and in the absence of wind, are all in compression. Under the effect of wind alone (not including gravity loads), columns on the windward side are in tension and the columns on the leeward side are in compression. The overturning moments of lateral wind loads are primarily resisted by tube action, i.e., axial shortening (compression) and elongation (tension) of the columns on all sides of the tube. The columns on the walls parallel to the wind direction are in tension on the windward side and in compression on the leeward side. The shear force from the wind loads is primarily resisted by frame action (in-plane bending of columns and spandrels) along the two faces parallel to the direction of the wind. In a framed tube system, the floor diaphragms play a key role since they carry lateral forces to the side walls of the building, thereby allowing tube action to take place. In addition, floor diaphragms provide lateral support for the stability of the columns.
That clarifies what I had on my mind: the lateral load from the wind is redirected by the construction into axial forces along the columns, so the whole design is not meant to support shear forces at all. It's all down to the 7/8 inch bolts.The overturning moments of lateral wind loads are primarily resisted by tube action, i.e., axial shortening (compression) and elongation (tension) of the columns on all sides of the tube. The columns on the walls parallel to the wind direction are in tension on the windward side and in compression on the leeward side. The shear force from the wind loads is primarily resisted by frame action (in-plane bending of columns and spandrels) along the two faces parallel to the direction of the wind.
One very minor point, and this is only because I happened to work in the building being referred to as "WFC3" for an extended period this past year--it is actually referred to commonly as either "200 Vesey" or "the Amex Building" (the former for its street address and the latter for its flagship tenant). I never heard or saw any mentioned of it as "WFC3". Carry on...
Yes, but in this example, what is being considered might be a solitary panel atop a larger sheet.Plates between staggered panels had 2 rows of 12 bolts attaching the spandrels one to another
And - unless some member knows of another example - the beam embedded in the corner of WTC3 is the sole example for which we have strong proof that it came from a toppling sheet of perimeter. And "have strong proof" could be "HAD strong proof" since we no longer seem to have access to the hi-res graphics proof.Yes, but in this example, what is being considered might be a solitary panel atop a larger sheet.
I think there was similar damage to the Deutsche Bank building from panels coming off the south face of 2 wtc.And - unless some member knows of another example - the beam embedded in the corner of WTC3 is the sole example for which we have strong proof that it came from a toppling sheet of perimeter. And "have strong proof" could be "HAD strong proof" since we no longer seem to have access to the hi-res graphics proof.
I certainly have never seen "strong proof" for the mechanism for any of the other those 6 or 7 "outlier" beams that traveled those long distances.
There were about half a dozen notable "outliers". Beams that became embedded in buildings at distances greater than most of the debris field. The topic was debated extensively 8 to 10 years ago. Mostly responding to truther insistence that they proved "Explosive Projection". Setting aside the Burden of Proof aspects most attempts at rebuttal relied on abstract speculation or based on examples of partial evidence.I think there was similar damage to the Deutsche Bank building from panels coming off the south face of 2 wtc.
Isn't that rather "begging the question" of the thread topic? Recent posts - from both "sides" - have conflated discussion of at least two different bits of beam. The one(s) embedded in the corner of WFC3 and the one in the roof of Winter Garden. And the status of "proof" is different for those two. One - the WFC example - has been subject of rigorous explanation elsewhere. The other - the Winter Garden example - subject to speculation but no extant "proof" either way.While the discussion of the outlier pieces is interesting, it seems to make no sense to even consider that their distance may have been the result of explosive detonations given that we can see very conclusively that none of them left the WTC at speeds indicative of having been propelled by explosives at the time of collapse initiation.
That is not the full picture - it is only partially correct. Certainly Christopher 7 went to speculation BUT much of the debunker responses were speculation. Pot v Kettle problems. And Christopher 7 raised several issues which (whether he realised it or not) were more advanced understanding of WTC collapse dynamics than the mainstream counter arguments put by opponents.This was demonstrated by Mick earlier in the thread here and then all but ignored by Christopher7, who in turn took the thread down a speculation rabbit hole it never needed to even approach.
I don't recall a robust discussion of "peel" dynamics... It's a term like "global collapse" which describes something identifiable... but lacks details. Although the interior of 7wtc collapse before the facade (asserted) its exterior did not peel but collapsed almost intact. The wtc was a "veerendeel-like" truss of staggered panels 36'h x 10'... while 7wtc was a moment frame with spandrels and attached curtain wall.Isn't that rather "begging the question" of the thread topic? Recent posts - from both "sides" - have conflated discussion of at least two different bits of beam. The one(s) embedded in the corner of WFC3 and the one in the roof of Winter Garden. And the status of "proof" is different for those two. One - the WFC example - has been subject of rigorous explanation elsewhere. The other - the Winter Garden example - subject to speculation but no extant "proof" either way.
I've raised the two procedural issues viz:
(a) Does proof still stand if the best visual evidence is no longer accessible; AND
(b) Is "debunking" (or "rebuttal" OR "explanation") only valid if it is posted on Metabunk.....
That is not the full picture - it is only partially correct. Certainly Christopher 7 went to speculation BUT much of the debunker responses were speculation. Pot v Kettle problems. And Christopher 7 raised several issues which (whether he realised it or not) were more advanced understanding of WTC collapse dynamics than the mainstream counter arguments put by opponents.