Chair of University Engineering Dept: Fire Did NOT Cause Collapse of WTC7 on 9/11

Discussion in '9/11' started by SamSkwamch, Sep 12, 2016.

  1. phoenyx

    phoenyx New Member

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    View attachment 45725

    I find it sad that this argument is still being used. Please read the following...

    From 9-11 Research:
    **
    Because the Windsor fire produced a partial collapse, some have argued that it validates the official account of the collapses of WTC Buildings 1, 2, and 7. Because the same fire was so massive and did not produce total collapse, others have cited it as evidence disproving that account.

    Steel Versus Steel-Reinforced Concrete

    In fact, comparisons between the Windsor tower and the WTC Towers are limited because of the very different structures of these buildings. The Twin Towers and Building 7 were both 100% steel-framed, with large wide-flange columns and box columns, some measuring over four feet wide and fabricated of steel up to five inches thick. Severe fires in other skyscrapers which, like the WTC Towers, were 100% steel-framed, have not produced even partial collapses.

    In contrast to the WTC Towers, the Windsor building was framed primarily in steel-reinforced concrete, with columns of concrete reinforced by thin sections of rebar. 4 The concrete pillars in the Windsor building are clearly visible in the photographs showing the intact core exposed by the collapsed facade. The very light construction of the perimeter, described below, makes it clear that the core was the main load-bearing component of the building.

    Before examining the partial collapse of the Windsor building more closely, we note that steel-framed and steel-reinforced-concrete-framed structures behave very differently in fires.

    Steel is a good conductor and concrete is a poor conductor of heat. Thus in a fire, a steel frame will conduct heat away from the hotspots into the larger structure. As long as the fire does not consume the larger structure, this heat conductivity will keep the temperatures of the frame well below the fire temperatures. The same is not true of steel-reinforced-concrete structures, since concrete is not a good thermal conductor, and the thermal conductivity of the rebar inside the concrete is limited by its small mass and the embedding matrix of concrete.
    Fires can cause spalling of concrete, but not of steel. This is because concrete has a small percentage of latent moisture, which is converted to steam by heat. Thus, a large fire can gradually erode a concrete structure to the point of collapse, whereas a fire can only threaten a steel-framed structure if it elevates steel temperatures to such an extent that it causes failures.

    Windsor Building Partial Collapse

    The observation that the Windsor Building is the only skyscraper to have suffered even a partial collapse as a result of fire suggests that the use of steel-reinforced-concrete framing was responsible. A closer look at the incident shows reality to be more complex. The portion of the building that collapsed consisted of the outer portions of floor slabs and perimeter walls throughout the upper third of the building (the 21st through 32nd floors). The outer walls consisted of steel box columns arranged on 1.8 meter centers and connected by narrow spandrel plates. The columns had square cross-sections 120mm on a side, and were fabricated of C-sections 7mm thick welded together. (these had a fraction of the dimensions, and were spaced about twice as far apart as the perimeter columns of the Twin Towers.) The perimeter columns lacked fireproofing throughout the upper third of the Windsor building. 5

    The Windsor Building fire engulfed the upper third of the building, but also spread downward as low as the fourth floor. A report by two fire safety experts in Japan highlighted three causes for the very wide extent of the fire:

    The lack of a sprinkler system
    Incorrect installation of spandrels
    The lack of fire prevention regulations in Spain

    The 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 collapses

    Time 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
    7
    These partial collapse events, spread over several hours, contrast with the implosion of WTC Building 7 in 7 seconds, and the total explosive collapses of each of the Twin Towers in under 17 seconds.

    **

    Source: http://911research.wtc7.net/wtc/analysis/compare/windsor.html
     
  2. Bob0627

    Bob0627 Well-Known Member

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    Except outside of normal expected sway parameters (due to wind, of which there was little on 9/11), the first tower didn't "lean" and no one has ever made that claim. What you claim you "told your friends" is silly hogwash. Most credible experts claim they never expected any of the towers to collapse, not even NIST. NIST first publicly claimed they couldn't get a handle on WTC7, meaning that even for those liars it wasn't something they expected. It took several more years for them to claim they had a eureka moment and the "obvious stares you in the face", which a leading expert (Halsey) scientifically declared after months of research was IMPOSSIBLE. As you said "only an expert in engineering and architecture is qualified to try to debunk NIST's analysis of the WTC 7 collapse" and he is much more than that. You on the other hand are not only nowhere near an expert but you're also full of it. Like I said, you fool no one.
     
  3. phoenyx

    phoenyx New Member

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    Ron, it's clear that Bob doesn't believe your contention that the first tower started to lean before it collapsed. Could you provide some evidence that it did, in fact, lean before collapse? I'm wondering if you're confusing pre collapse with when the South Tower was -actually- collapsing? For more on that, please take a look at the following article:
    Physics doesn't lie: Tilting South Tower gives away Demolition of Trade Center
     

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