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Post by nomuse on Mar 9, 2007 3:24:35 GMT -4
Uh, huh. So steel conducts heat so well it can not sustain localized hotspots? Crash! There went all the improvised yokes I built for my collection of Sky-Cycs. And boy do my hands hurt now....I did all the bending of these quarter-inch steel bar stock items with MAPP gas and.......BARE hands.
And yet concrete is so vulnerable to heat it spalls away and disintegrates? Someone better tell the Part Service....all those concrete barbeque pits need to go.....
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Post by feelfree222 on Mar 9, 2007 3:31:55 GMT -4
Because many examples you and other cite concerns only partial collapse. [emphasis mine] 1 (one) single, solitary structural steel frame building collapsing because of fire at any time in the last 100 years is enough to render his claim false. [Edit to add:] From part 2 of this article, linked previously by PhantomWolf: Despite the fire-fighters' efforts, Building One collapsed completely at approximately 5:14 p.m. [emphasis mine] No other evidence need be presented. Rice's claim is demonstrably and unquestionably false. No it is still in line with Rice claims note the "If" stance as expected by Rice "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."
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Post by feelfree222 on Mar 9, 2007 3:36:18 GMT -4
Uh, huh. So steel conducts heat so well it can not sustain localized hotspots? Crash! There went all the improvised yokes I built for my collection of Sky-Cycs. And boy do my hands hurt now....I did all the bending of these quarter-inch steel bar stock items with MAPP gas and.......BARE hands. And yet concrete is so vulnerable to heat it spalls away and disintegrates? Someone better tell the part service....all those concrete barbeque pits need to go..... -Well i have simply mispoke what they said.-sorry 911research.wtc7.net/wtc/analysis/compare/windsor.htmlThe Windsor Building fire demonstrates that a huge building-consuming fire, after burning for many hours can produce the collapse of parts of the building with weak steel supports lacking fire protection. It also shows that the collapse events that do occur are gradual and partial.Estimated time frame of collapsesTime Collapse Situation 1:29 East face of the 21st floor collapsed 1:37 South middle section of several floors above the 21st floor gradually collapsed 1:50 Parts of floor slab with curtain walls collapsed 2:02 Parts of floor slab with curtain walls collapsed 2:11 Parts of floor slab with curtain walls collapsed 2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor 2:17 Parts of floor slab with curtain walls collapsed 2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed 2:51 Southeast corner of about 18th ~ 20th floors collapsed 3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor 3:48 Fire flame spurted out below the Upper Technical Floor 4:17 Debris on the Upper Technical Floor fell down
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Post by Data Cable on Mar 9, 2007 3:47:24 GMT -4
No it is still in line with Rice claims note the "If" stance as expected by Rice Nope. He makes an assertion, he does not support it. And this claim: 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.
Has been proven demonstrably false.
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Post by feelfree222 on Mar 9, 2007 3:51:34 GMT -4
No it is still in line with Rice claims note the "If" stance as expected by Rice Nope. He makes an assertion, he does not support it. And this claim: 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.
Has been proven demonstrably false. I concede , for that part of the claim .
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Post by Data Cable on Mar 9, 2007 3:54:07 GMT -4
It also shows that the collapse events that do occur are gradual and partial. It shows that the collapse events that did occur in that case were gradual and partial. This in no way demonstrates that all such cases will behave similarly. Besides, there are numerous other significant differences between WTC 1/2 and Windsor Tower, both in the structures as well as the events surrounding the collapses, not the least of which being airliners crashed into the WTC towers[/b].
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Post by feelfree222 on Mar 9, 2007 4:01:31 GMT -4
Yep but Rice take all of that into consideration as I mentioned in page 4 Recap I don't see anything in his last few sentences that would limit his argument to skyscrapers. For what it's worth, where he goes wrong in that argument is in ignoring the ten-fold difference in kinetic energy between the design case of an airliner at typical approach speed and the actual cruise-speed impact, with consequently greater structural damage including damage to the fireproofing on the steel beams. But he take this into consideration .... I resume some previous conversations about the following quote(s) made by Rice “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.I try an explanation Because that suppose that the weldings whose fixed the connectors to the steel columns have not broken under the weight and pressure of the broken floors debris falling onto the floor they support.----------------------------------- Here the quote "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 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 free-fall speed as if the 100,000, or more, tons of supporting structural-steel framework underneath didn’t exist.
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Post by nomuse on Mar 9, 2007 4:17:08 GMT -4
That's a horrible assumption, as I pointed out in my very first post. If you fail a significant proportion of the load-bearing members you fail the structure, _regardless_ of the condition of the remaining members.
That's basic engineering, and if he doesn't grasp that he doesn't belong in a classroom -- on _either_ side of the desk.
As for the other wonderful assumption he makes....well, you do understand that every time a boat moves forward it impacts a bunch of water. It has to, in fact, overcome the inertia of a quantity of water equivalent to its own weight (pushing it aside) in order to move. So how is it a boat can move forward with even a light breeze? Well, it is a matter of proportion. The inertia of all that water is rather less than the force being applied to the sails.
Similarly, it is already demonstrated that a mere airplane can crush one of the columns in a WTC tower. So just imagine how much resistance that column can offer when you throw a thirty-story building at it! Not a lot, proportionally. The building notices in about the same way you notice how you have to shoulder aside a cubic meter of air every time you try to walk.
Yes, it moved as if the supporting structure _hardly_ existed. I might draw your attention, by the by, to the collapse time given for the twin towers in your own link about the Windsor Building fire -- hardly "free fall" time there. Well above the ten seconds the "engineer" in the above quote gives.
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Post by feelfree222 on Mar 9, 2007 4:23:48 GMT -4
....as if the 100,000, or more, tons of supporting structural-steel framework underneath didn’t exist.
That is the intact structure below the point of impact down to the ground he is talking about.
To late for me i go to sleep.
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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 9, 2007 6:59:25 GMT -4
Uh, huh. So steel conducts heat so well it can not sustain localized hotspots? Crash! There went all the improvised yokes I built for my collection of Sky-Cycs. And boy do my hands hurt now....I did all the bending of these quarter-inch steel bar stock items with MAPP gas and.......BARE hands. And yet concrete is so vulnerable to heat it spalls away and disintegrates? Someone better tell the part service....all those concrete barbeque pits need to go..... -Well i have simply mispoke what they said.-sorry 911research.wtc7.net/wtc/analysis/compare/windsor.htmlThe Windsor Building fire demonstrates that a huge building-consuming fire, after burning for many hours can produce the collapse of parts of the building with weak steel supports lacking fire protection. It also shows that the collapse events that do occur are gradual and partial.Estimated time frame of collapsesTime Collapse Situation 1:29 East face of the 21st floor collapsed 1:37 South middle section of several floors above the 21st floor gradually collapsed 1:50 Parts of floor slab with curtain walls collapsed 2:02 Parts of floor slab with curtain walls collapsed 2:11 Parts of floor slab with curtain walls collapsed 2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor 2:17 Parts of floor slab with curtain walls collapsed 2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed 2:51 Southeast corner of about 18th ~ 20th floors collapsed 3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor 3:48 Fire flame spurted out below the Upper Technical Floor 4:17 Debris on the Upper Technical Floor fell down The Windsor was primarilly a concrete building. The partial collapses occured when steel elements failed and concrete ones held.
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Post by nomuse on Mar 9, 2007 8:25:51 GMT -4
Looking for a total collapse of a steel-framed _skyscraper_ is a bit like looking at a mechanical failure that causes the wings to come off an airplane and declaring that it hasn't been determined that said failure would cause the plane to _crash_.
We can demonstrate what happens to steel framing in a fire. The real world has given us examples of this. We don't need to see this happening to several floors in a very tall building to understand what would happen after that!
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Post by feelfree222 on Mar 9, 2007 17:09:17 GMT -4
We can demonstrate what happens to steel framing in a fire. The real world has given us examples of this. We don't need to see this happening to several floors in a very tall building to understand what would happen after that! OK so i take your claim words for words .... remember your point as stated is about fires only Here are Other Steel Framed Skyscraper Fires only exeption among those listed The Windsor Building,was framed in steel-reinforced concrete rather than steel. Hence it is described on a separate page, which notes differences between the response of these different types of structures to fires. 911research.wtc7.net/wtc/analysis/compare/fires.html
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Post by nomuse on Mar 9, 2007 18:26:05 GMT -4
From the same source you linked to.
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Post by sts60 on Mar 9, 2007 18:48:50 GMT -4
Let’s assume the unlikelihood that these fires could weaken all of the columns to the same degree of heat intensity
"Heat intensity"? Did he really say that?
The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds 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.
I listened to some of our USAR guys describe a concrete parking garage collapse. They said they were struck (not literally! fortunately!) by the quickness of the event: "It was just BoomBoomBoom."
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Post by Data Cable on Mar 9, 2007 23:40:51 GMT -4
The Windsor Building,was framed in steel-reinforced concrete rather than steel. No, it was framed with steel-reinforced concrete and structural steel beams, the latter of which collapsed from the fire.
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