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Background Attack Aftermath Evidence Misinformation Analysis Memorial

Distributed Explosives

Theories that Distributed High Explosives Destroyed the Twin Towers

Of the types of Twin Tower demolition theories, the most widely embraced are ones describing the detonation of numerous explosive charges hidden in locations from the top to the bottom of the Towers. The explosives would be used to shatter the steel structure, much like conventional demolitions, but the timing of detonations would be made to start near the crash zones and move downward, to simulate a progressive collapse.

Perhaps the first person to clearly articulate the distributed explosives theory was Eric Hufschmid, in his book Painful Questions. 1   He describes how packages containing high explosives such as RDX could have been hidden in the Towers. Each package would contain a detonator controlled by a radio receiver, allowing it to be individually detonated by remote control, perhaps from a control center in Building 7.

Conventional Demolitions

Conventional demolitions employ numerous explosive charges, placed adjacent to all the vertical support structures of the building and on multiple levels, starting at the ground. Careful timing of the detonations is essential to achieving vertical collapse of the building into its footprint. Typically, charges on the interior columns at ground level are detonated first, causing the central portion of the building to begin to collapse, pulling the perimeter of the building inward. Detonations then proceed outward, destroying perimeter columns after inner columns, and upward, destroying sections of columns just as they reach the ground. The net effect is a vertical collapse in which the building implodes, falling into a rubble pile almost entirely within the building's footprint.

Most conventional demolitions use detonation cords to set off the explosive charges. However, equipment currently on the market, such as the HiEx TeleBlaster, allows the detonation of charges without the use of cords or wires. 2   Such wireless equipment allows demolitions to be set up in a much less intrusive manner than was previously possible.

Twin Towers' Demolition

The Twin Towers' demolition, if achieved through distributed explosive charges, was engineered in a decidedly different manner from conventional demolitions to make it consistent with the story that the Towers collapsed as a result of the jet impacts and fires. The main differences were:

  • Explosions started at the impact zone and proceeded down the intact portion of the Tower and up the overhanging portion, instead of starting at ground level.
  • Much more powerful explosives were used than in a conventional demolition.
  • In the South Tower demolition, the overhanging portion was allowed to tip for a few seconds before the larger explosions commenced.

The Twin Tower demolitions resembled conventional demolitions in that the Towers fell with dead-centered vertical symmetry; but differed in that material was ejected horizontally in all directions, resulting in rubble piles several times the diameter of the Towers' footprints. The Twin Towers exploded rather than imploded.

The Twin Towers were also demolished at a more rapid rate than is the case in conventional demolitions. When buildings are demolished from the ground up, gravity is typically relied upon to do most of the work once several floors have been demolished, and the upper portion of the building is falling with considerable kinetic energy. The tapping of that energy to break up the structure slows the fall. In the case of the Twin Towers, it appeared that the explosive events were progressing down the Towers' intact portions at a rate only slightly slower than free-fall.

Disaster Engineering

One might ask questions about two features of the demolition, both of which would seem to detract from the realism of simulated gravity-driven collapses.

  • Why would the perpetrators use much greater quantities of explosives than in a conventional demolition?
  • Why would they destroy the Towers at such a rapid rate?

The answer to the first question probably has to do with economics. The use of less explosives would fail to break up the Towers' structures as thoroughly. Since the destruction started a thousand feet aloft, large falling pieces could have been deflected hundreds of feet when they hit other objects near the ground. Had not the Towers' perimeter walls been so thoroughly shredded, they might have fallen away in large sections, pivoting large distances from the Towers. The result could have been more damage to buildings outside the World Trade Center complex than occurred. While the high explosives threw pieces of the perimeter wall as much as 500 feet laterally, their distribution was more predictable and their sizes were smaller and less likely to do serious damage than might have happened with less powerful explosives.

The answer to the second question probably has to do with hiding obvious evidence of explosions. Increasingly powerful explosions occurred as the destruction progressed down the Towers, perhaps to ensure the thorough destruction of the stronger structures lower in the Towers. If the rate at which the explosives were detonated was not fast enough to stay ahead of the falling rubble, the perpetrators ran the risk that the rubble would fall away from the moving zone of destruction, revealing large obvious explosions at the top of the exposed structures.

Contrary Evidence

The distributed explosives theory can easily explain the gross features of the collapses from the top-to-bottom destruction to the pulverization of the Towers' materials. However, there are a number of more subtle features of the collapses that do not appear to be consistent with this theory, at least in its simplest form. The following collapse features suggest that the demolition of the Towers was accomplished using technologies other than just distributed conventional explosives. In contrast, many of the same features do appear to be consistent with the thermobarics theory, and the final one suggests the thermite theory.

  • Absence of high blast pressures in collapse onsets
    Careful study of photographs and videos of both collapses shows that the perimeter walls do not immediately blow out in the way one would expect if explosives adjacent ot the perimeter columns were used to destroy them. Rather, the walls telescope as they disappear into the burgeoning dust clouds, to partially reappear seconds later as fragments outracing the dust cloud.
  • Rapid degradation of structure
    Features of the onset of both collapses indicate that structures around and above the crash zones lost almost all their strength. In the South Tower, the top not only tips, it bends: The outer wall exhibits a peculiar curve extending about 15 floors above the crash zone. Similarly, in the North Tower, the top begins to telescope straight down with no evidence of bucking in the perimeter columns. In both cases the structure's strength seems to disappear even before any of the explosive features appear.
  • Uniformity of pulverization
    Photographs and reports from Ground Zero indicate that the vast majority of the estimated 90,000 tons of concrete in each Tower was turned to fine dust, not a mixture of dust and gravel or larger chunks. Since blast pressures from explosive charges fall off with the square of the distance from the source, achieving such thorough pulverization with distributed explosives would seem to have required a huge number of individual packages being placed throughout the building.
  • Vaporization of people
    Over 1000 victims were never identified despite over a year of efforts to identify victims from even the smallest fragments using DNA. Explosive charges would be unlikely to so thoroughly degrade the remains of so many people.
  • Persistence of core structures
    In both collapses, a large section of the core structure extending up over 600 feet remains standing for a few seconds and then collapses. The persistent remnant of the North Tower is very narrow and delicate. It is difficult to imagine how such structures could have survived the blast pressures generated by demolition waves of explosive charges, only to themselves collapse a few seconds later.
  • Rapid oxidation and intergranular melting of steel pieces
    The limited metallurgical examination of some of the few pieces of structural steel that escaped the blast furnaces shows very peculiar features, such as rapid oxidation turning inch-thick steel into paper-thin scrolled pieces, cavitation giving steel the appearance of Swiss cheese, and intragranular melting. These suggest a more exotic process of destruction than mere explosives.

References

1. Painful Questions, Endpoint Software,
2. The HiEx TeleBlaster II, hiex.bc.ca, [cached]

page last modified: 2011-07-22