Normal Thermite Can Cut Vertically Through Steel Proof, Debunkers claims finally destroyed
Nov 11 2010, 08:51 AM
Group: Private Forum Pilot
Joined: 8-November 08
Member No.: 3,978
Hey look check this out guys this video is great this is flaming fantastic, it is a video of well known 9/11 truther who assembles
some structural steel the way it would have been assembled in the wtc twin towers and other buildings made of structural steel
and he cuts righ through the thick structural steel, well thats kind of a lie he cuts almost all the way through the entire length of
the steel member, using normal thermite using barrium nitrate and sulphur well if this is how it was really done on 911 those cuts even if they dont cut completely all the way still would have weakened the structural steel enough to cause the entire structure to loose alot of it strength enough to bring about a casatrophic global collapse resulting in a gravity driven CD, and watch when he uses the thermite and creates his own charges and the thermite explodes it even creates a hole giving a swiss cheese like appearance, similar to the samples found from the wtc buildings.
Does this video completely destroy the duh bunkers claims that thermite cannot create vertical cuts through steel beams, and also there
claims that you couldnt use normal thermite to demolish a steel framed building?
I have another question why would you use barrium nitrate and sulphur mixed in with normal thermite to cut through structural steel
how would these chemicals improve the thermites cutting power?
9/11 Experiments: The Great Thermate Debate
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Nov 25 2010, 12:08 PM
Joined: 23-December 09
Member No.: 4,814
No problem. Let me try to explain what I think happened, but it would take many posts to do this hypothesis justice.
Let me establish at the outset that I can't explain with any level of certainty how the collapse was initiated. Let's just discuss tower 1 for now. We can say that the plane strike or explosion which began the event did not collapse the tower. The loads carried by the destroyed columns on floors 93-99 were redistributed. This is possible because the columns are interconnected with lateral beams which normally support floors (in the core) and provide stiffness to the columns so they won't buckle. Any column is constrained according to Euler's formula regarding the slenderness ratio of unsupported axially loaded columns. When a column is "taken out" its load is "transferred" to adjacent columns via horizontal members such as the spandrel in the facade and the lateral steel in the core. These members are not designed or intended to support axial loads however.
The floor dead and live loads where attached to the SIDE of the colunns. These floor loads were carried by the floor trusses at 80" OC which then rested on angles which were welded to stand off plates at the facade. The plates were welded to the spandrels which formed the inside web of the facade box column. There were cross trusses which also transferred the loads from one truss to the other making the floor act like a stiffer membrane/plate. The floor itself was remarkably thin being only 4" or so at its thickest point and 2" or so at its thinnest. It was poured into B type of similar corrugated metal decking. Conduits for electrical wires were placed inside the pour as well.
The floor system was designed to carry 100# per square foot with a acceptable deflection at mid span which is typically 1/360 or 1/720th of the span under the design load. When loads exceed the design load the deflection increases until the yield strength is reached and then the material will fail catastrophically. Stretch a rubber band too much and it snaps. All materials will deform elastically under load and fail catastrophically when the ultimate yield strength is reached.
The floors were a composite system which means that it had many different components each with separate structural characteristics. The engineers design it so that the weakest element "drives" the design. So when the floors were overloaded it is still hard to determine what failed because the overloads are not uniformly applied, and each element will have different structural properties. If you don't use enough bolts a connection will fail and the bolts could shear or rip out. If you add more you weaken the material they are bolting together by removing too much material. You can use stronger bolts and so forth. This is a complex "balancing act" to design complex structures.
The floors all had the same trusses though the trusses supported different loads. This is hard to explain without drawings, but again the design would be driven by the truss which had to carry the most load. This makes other trusses somewhat over designed - or the truss seats and so forth. It also means that the over designed elements will fail AFTER not at the same time... they will "hold" more load and last a bit longer. This is only one reason why a pancake collapse is not possible.
When a floor or section of a floor is overloaded past the ultimate yield strength it must fail. It's hard to say what will fail first, but it could be the slab which shatters, or the metal pan which rips like foil, or the truss which has its steel bar webs part or break free of the bottom angles which make up the tension chord, or the tension angles (bottom chord) could part. The failures can propagate as one element fails and is "unloaded" the other elements have to do more "work" a 4" slab cannot span the distances in the towers without the trusses. If a truss fails, the floor are it supports will crack and shatter.
The planners understood that once the safety factor of the elements of the composite floor were exceeded it would fail and that means the floor would collapse and break apart and drop onto the floor below and this would cause the floor below to fail and so on. But remember that to fail the floor or a portion of it the load had to increase PAST the safety factor which in the case of the floors was reputed to be 5 or so. This means that that they would carry not 100# per square foor, but 500# per square foot. More than that, they would fail.
So let's do some basic math here. The floors had concrete which weighed 94#/ cu foot, they had the weight of the trusses and the metal pans, the ceiling materials, ducts and so forth. Let's say the floors weighed about 50# per square foot and the live load - furniture and people and office contents, was 50% of the 100# or 50# per square foot and then there was the dead load of any walls etc at say 10# per square foot. For this exercise the exact weights are not crucial. SO we have the floor and contents weighing about 110# per square foot. If one floor were to be placed on the one below it would add 110# per square foot to its already 50# it was supporting. It's now supporting 160# which is within its safety factor. it might sag but it wouldn't collapse. This is not taking into account the dynamic load which amplifies a static load considerably. When a second floor comes down on the overloaded floor it adds another 110# and the floor now is carrying not 50# but 270#. This is assuming a uniform load distribution which likely was not occurring. Some areas would carry more and some less. The floor would deflect/sag more but hold. Add a third floor to this and now it is carrying 380# and still within the safety factor. Remember that this is NOT considering the dynamic load when the weight is dropped onto the floor from 12, 24 and 36' high. The 4th floor pushes the load right to the safety factor. Considering the dynamic loading it's likely that the floor failed before it had to carry 4 additional floors. It's likely that the failures were local ie parts of the floor failed before others.
This descending process took about 4 seconds for 17 floors and there was some acceleration. That is a separate discussion. But it wasn't at free fall but about 70% of for about a few floor heights of descent. Looking at the video we essentially see the lower floors of the top section "falling into / onto" top floor (92) of the lower section. It took about 1 - 1.5 seconds for 4 floors of descent to deliver 4 floor masses to the 92nd floor. Some of this may have crashed through to floor 91. In the next second or two 4 or 5 more floors came down and this overloaded 92 and the parts of 91 which 92 had collapsed on. This now began the gravitational phase of the collapse in the lower section. The floor mass which had crashed onto 92 and 91 began failing the floors below as more and more floors from above 100-109 dropped over 200 feet onto undamaged floor perhaps somewhere in the 80s. Some of the mass fell over the side of the towers as the facades broke away. We can see them fall over and actually see a few panels lead the heavier than air descending debris plume. By floor 80 the mass represents 30 floors or over 1/4 of the tower's floor mass which was about 200,000 tons. This is about 60,000 tons using the crude and conservative figures above. This chaotic crushing mass was randomly distributed over the 30,000 square feet of each floor. Each square foot or floor was being pounded by 2 tons and it was designed to support a static load of 100#.
But each floor did resist for a brief instant until the yield strength was reached and it failed. Each floor would slow the accelerating avalanche and hold it at about 65 mph or 100 feet per second. The mass would race past the facade which could not contain it and it too yielded and was pushed out. The facade did not have the strength to contain the collapse rubble/debris nor stand alone without lateral support which was provided by the floor system. The facade peeled and was pushed away and toppled over.
The core was assaulted by the collapsing floors. It had only 2 layers of 5/8" gypsum wall board to keep the avalanche out side confined to the floor area. The avalanche also plunged inside the core and ripped many of the lateral beams off the columns leaving them precariously too tall and thin for their immense height. The too tall columns were shaken for the lateral assault and began to oscillate and sway breaking the relatively weak splices which connected each 36' section on to the other.
The core could have stood the full height if all its lateral reinforcing was not stripped off. But it was and so it too came down as Euler's formula predict.
The collapse was not at free fall acceleration. Only the beginning shows acceleration and that is about 70% of free fall. The rest of the collapse was about 65 mph which is about 13 seconds or so. The mass DID accelerate for about 6 stories. A free falling body would reach speeds of 150 feet per second after 3 seconds of fall. The acceleration I believe was clocked at about 70% of free fall and so the mass was moving at ~70% x 150 feet per second and this is about 100 feet per second of 60+ mph.
seconds / ft
0 / 0
0.5 / 5
1 / 16
1.5 / 36
2 / 64
2.5 / 100
3 / 145
The floor debris or what was left of it would of course come straight down much like pouring sand would. Like pouring sand in a weak container it would push against the side as grain does in a silo. In the case of the towers this was enough pressure to break apart the facade and the core gypsum walls.
Seven was a bit different and it was more like an implosion style demolition where the exterior structure is pulled in by the collapse core structure. The floors collapsed straight down and also pulverize themselves. This is what is expected when that sort of mass drops. The pressures are enormous.
No demolition was ever done on a structure taller than 25 stories before or after.
Both designs were able to be taken down using the floor collapse approach because of the long span column free light weight floors outside the core. This was not hard to understand. The trick was to get the tops off column and then gravity would do the rest and quite close to what appears as free fall. Remember by volume the floor part was 97% air - slabs of 4" separated by 11'-8" of air. The fall was 96% through air. No columns were crushed and the stronger columns at the bottom had no part to play in arresting the floor collapse.
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