Columns

The core columns were steel box-columns that were continuous for their entire height, going from their bedrock anchors in the sub-basements to near the towers' tops, where they transitioned to H-beams. Box columns, more than 1000 feet long, were built as the towers rose by welding together sections several stories tall. The sections were fabricated by mills in Japan that were uniquely equipped to produce the large pieces.

Some core columns had outside dimensions of 36 inches by 16 inches, while others had larger dimensions of 52 inches by 22 inches. The core columns were oriented so that their longer dimensions were perpendicular to the core structures' longer, 133-foot-wide sides. Construction photographs found at the Skyscraper Museum in New York City indicate that the outermost rows of core columns on the cores' longer sides were of the larger dimensions. Both the FEMA World Trade Center Building Performance Study and the NIST's Draft Report on the Twin Towers fail to disclose the dimensions of the core columns, and the NIST Report implies that only the four core columns on each core's corners had larger dimensions.

Like the perimeter columns -- and like steel columns in all tall buildings -- the thickness of the steel in the core columns tapered from bottom to top. Near the bottoms of the towers the steel was four inches thick, whereas near the tops it may have been as little as 1/4th inch thick - two inches thick half way up. The bottom photo shows the base of one of the larger core columns, where the steel was five inches thick. The bases of the columns also had slabs of steel running through their centers, making them almost solid.

Column Arrangement

The exact arrangement of the columns and how they were cross-braced is not apparent from public documents such as FEMA's World Trade Center Building Performance Study. The arrangement of box columns depicted in Figure 2-10 of Chapter 2 (pictured to the right) seems plausible, even though it contradicts other illustrations in the report showing a more random arrangement. It depicts the top floors of a tower and does not indicate the widths of the columns on a typical floor.
 

Cross-Bracing

Construction photographs show that the core columns were connected to each other at each floor by large square girders and I-beams about two feet deep. The smaller core columns were surrounded by perpendicular I-beams approximately three feet deep. In addition, the tops of core structures were further connected by the sloping beams of the hat truss structures.

Consider the following: if the pancaking effect caused the total building failure, why is it that no video of either of the WTC collapses shows any sign of stutter between floor collapses, which should have been very apparent especially in the first few floors of collapse when the speed of gravitational collapse was small? Consider also that apologists for the official conspiracy theory propose that 30% of the gravitational collapse energy was necessary to create the pyroclastic cloud of debris: that is, in their own analysis, this energy came out of the gravitational energy. This means that the time of fall would have been slowed further than what was observed. When a body of mass m falls from a height h, acted upon by gravitational acceleration g, it converts its potential energy PE = m x g x h into kinetic energy KE = (1/2) x m x v². Here h = (1/2) x g x t², t = time of fall, and v = g x t, where v = velocity. Removal of 30% of the PE to pulverize concrete essentially reduces the amount of energy available from falling, effectively reducing the gravitational acceleration to something less than g.

Substituting, in the above equations we have (1.0 - 0.3) x PE = 0.7 x PE = m x G x h, where PE, m and h are as before and G = the effective gravitational acceleration. Hence, comparing terms for PE, G = 0.7 x g. The time of collapse under G will also increase. If we let the effective collapse time be T, then comparing terms for constant h,

(1/2) x g x t² = (1/2) x G x T² = (1/2) x 0.7 x g x T².

Hence, t² = 0.7 x T², or (t/T) = (0.7)^1/2 = 0.837. Or, T = 1.195 t.

Now the observed time t = 10 seconds (a free fall time, the fastest possible time under g = 9.8 m/sec² = 32 ft/sec² = 32 ft/s²). For the cloud debris creation to absorb 30% of the gravitational energy, the observed time of fall would be 10s x 1.195, or almost 12 seconds. This long a collapse time was observed by no one. Clearly, there are serious flaws in the official explanation/conspiracy theory.

 

The official media/government conspiracy theorists may propose a figure of 30%, but Jim Hoffman (October 16th, 2003) [Ref. (8)] actually calculates that:

• 111,000 KWH is generated by the collapse of each tower (mass = 1.97 x 10¹¹ grams falling average of 207 meters)
• 135,000 KWH is needed to crush the concrete (9 x 10¹⁰ grams to 60 micron powder)
• 2,682,000 KWH is needed to create the dust cloud (this assumes a sufficient source of water or this figure increases dramatically)

 

This means that 122% of the gravitational collapse energy was necessary just to pulverize the concrete (let alone create the dust cloud), that is, more energy was needed just to pulverize the concrete than was generated by the collapse. This, of course, means that explosives, thermite or some other energy source must have supplied the extra energy.

 

Consider also the seismographic evidence proving enormous amounts of energy (actually MUCH more than the building could provide) entering THE GROUND, at the beginning of the collapse! This is not a mere smoking gun, its a smoking cannon.....

History Channel Admits WTC Tower Fell At Freefall Speed [About 10 seconds]