Tuesday, February 2, 2010

The Twin Towers:

What Really Destroyed Them?

The South Tower's top first started to lean, then disintegrated before falling.

Nearly everyone was shocked to see the towers explode into dust in mid-air, but we were not given any time to ask how this happened, as the official explanation was already at hand: the buildings, we were told, collapsed of their own weight.

We were told that no-one had ever anticipated fuel-laden jumbo-jets crashing into the towers, and that the jet fuel burned with the heat of a nuclear power plant and melted the steal columns of the towers' cores. Faced with the fact that a jet fuel fire could only reach a fraction of the temperature required to melt the buildings' structural steel, the "truss theory" was promoted. Later endorsed by FEMA, it holds that the fires weakened flimsy trusses supporting the floors, causing the floors to fall on one another in a chain-reaction.
This document examines fallacies in the official explanation:

  • It is not consistent with the laws of physics.
  • Its collapse scenario doesn't look anything like what happened.
  • It misrepresents engineering practices and the Twin Towers' design.
  • It was uninformed by any forensic analysis of the physical evidence.

Officials Destroyed the Physical Evidence.

After the disaster, the site was sealed off. People were threatened with arrest for merely taking pictures of Ground Zero. Officials running the "clean up" operation implemented a plan by Controlled Demolition Inc. to recycle the steel: the remains of the towers were shipped by scrap metal vendors to overseas blast furnaces, mainly in India and China. The vast majority of the structural steel was never seen by investigators, FEMA'sBuilding Assessment Performance Team, who were not even allowed access to Ground Zero.

The site of the vast crime that "changed everything", and of the largest and least understood structural failures in history, was not allowed to be examined for clues.

Nor can the public verify details about the buildings' design crucial to FEMA's theory, since the blueprints have not been released. The description of the towers' structure in their official report leaves over 20% of the steel known to have been used in their construction unaccounted for. By the time FEMA's report was published, Ground Zero had been scrubbed.

The towers easily survived the jet impacts. The impact holes quickly became dark, indicating absence of fires in the the towers' cores.

The Towers Were Designed to Survive Large Jet Collisions.

Each tower was designed to survive the impact and fire from a collision by a 707-340 carrying 23,000 gallons of fuel. The similar- sized 767-200s that hit the towers were each carrying about 10,000 gallons of fuel.

Each tower was supported by both a palisade of columns forming its outer wall and a bundle of 47 massive steel columns in its core structure. Like all large engineered structures, the towers were over-engineered to support many times anticipated loads, to survive severe and improbable events, including bombings and fires. The plane crashes severed about 33 of the North Tower's and 24 of the South Tower's 240 perimeter columns. The South Tower impact trajectory suggests its core structure was barely damaged. Absent severe winds and earthquakes, each tower should have easily survived damage to even a majority of its columns. Each tower's crash and fire damage was limited to an asymmetrical minority of columns and a few floors. Yet each tower collapsed symmetrically, and into small pieces.

The Fires Were Not Unusually Severe.

Since jet fuel (kerosene) boils easily and its vapors ignite easily, it burns off rapidly. FEMA admits the fuel must have been used up within "a few minutes". Thereafter the fires burned fuels similar to those in ordinary office fires. The impact holes became dard shortly after each collision, and the smoke darkened over time -- a sign of oxygen-starved fires. After the South Tower had been hit, at least 18 people evacuated from above the impact zone down stairwells passing through it.

There is no evidence that, even at their hottest immediately after the impacts, the fires approached the 700 degrees C required to significantly soften steel. Such temperatures would have caused regions of the building to glow red hot in broad daylight. The oxygen-starved fires likely remained below 400 degrees C, and would be harmless to the steel frame even in the absence of insulation. There is no evidence that the fires ever damaged the core structures. Note that softening of steel by high temperatures is reversible, and that steel is a good conductor of heat. If any structural steel had lost strength in the first minutes of the fires, it would have regained most of it as the fires cooled after consuming the jet fuel.

Fires Don't Cause Skyscrapers to Collapse.

If WTC towers 1 and 2 and WTC 7 collapsed because of the fires it would be the first time in history that a steel-frame skyscraper totally collapsed because of fires or any other cause or combination of causes other than controlled demolition.
47-story WTC 7 sustained no impacts from aircraft or large falling objects, and only small fires were observed within it prior to its precisely vertical "collapse" into a small tidy rubble pile, 7 hours after the North Tower fell.

The South Tower exploded into dust, 56 minutes after the jet impact.

Vertical Collapses Indicate Demolition.

The towers fell almost perfectly vertically, while spewing debris laterally. It is impossible that the aircraft impacts and fires could result in damage so perfectly synchronized and symmetrical as to cause the simultaneous and balanced failures in the structure required for such vertical collapses.

The official explanation that the outer wall channeled the collapse to within the building's footprint doesn't fit the reality that the outer wall was shredded before the bulk of the falling mass reached it. It also fails to acknowledge that the dense core would make the building's top fall like a tree.

The Towers Exploded.

In a gravity-driven collapse of the type we were told happened, the floors would crash down within the outer wall, and the wall's steel columns might buckle. The core would remain standing even if the outer wall fell apart.

The explosive disintegrations we witnessed don't look anything like that. Thick clouds of dust and debris are seen billowing from the towers even in the first seconds of their destructions when their tops were falling slowly. The remains of the towers consisted of scraps of metal, papers, and fine dust. The concrete, glass, gypsum, and other nonmetallic building constituents were thoroughly pulverized to microscopic particles.

The Towers Were Pulverized and Shredded in the Air.

The towers exploded into columns of dust resembling the pyroclastic flows of volcanoes. The thick clouds of pulverized concrete were ejected at regular intervals below the huge mushrooming clouds of dust that devoured each tower. Gravity might explain pulverization of concrete hitting the ground, but not in the air, and not in the early stage of each collapse when the top was moving slowly.

The steel box-beam grids of the buildings' outer walls were chopped onto small sections, and hurled tens and hundreds of feet, rather than peeling off. The massive steel box beams of the buildings' cores were also broken up into short pieces.

The North Tower was thoroughly pulverized in the air, creating a volcano-like cloud thick dust that expanded to several times the building's volume.

The collapse of floors and buckling of the outer walls proposed by the "truss theory" cannot account for the conversion of the concrete into dust in mid-air, the fine chopping of the outer walls and hurling of their pieces hundreds of feet, or the complete destruction of the buildings' resilient cores.

The Towers' Tops Fell Without Resistance.

The towers fell at near the speed of a falling object encountering no resistance. Video recordings show both towers fell completely in about 15 seconds -- only slightly longer than would take an object to fall from the towers' roofs in a vacuum. But unless the intact portion of the building were demolished before the falling portion encountered it, it would have greatly slowed (and in fact halted) the fall, since the energy to crush each story and accelerate its mass downward would have to come from the kinetic energy of falling mass.

The towers could not have collapsed for the reasons cited, and if they could, they would not have exploded into dust and dropped at near free-fall speed.

Find detailed evidence about the Twin Towers' demolition
at these websites:

wtc7.net
911research.wtc7.net
911research.wtc7.net/talks/towers/