Demolition Technology
The
explosive destruction
of the Twin Towers,
and the
implosion
of the Building 7 all exhibited the key features of controlled demolitions:
- The destruction of each building was systematic and thorough,
leaving no large intact structures.
- The three tall buildings were brought down
in a highly symmetric fashion,
each tower depositing its mass in a radially symmetric pattern
around its central axis.
Bringing tall steel-framed buildings down into their footprints
is a considerable engineering feat since it necessitates
overcoming the natural tendency of such structures to topple.
It is accomplished in conventional controlled demolitions
by the synchronized detonation of numerous small explosive charges,
placed adjacent to support columns throughout the building.
Through precise timing of the detonations
of the hundreds or thousands of explosive packages,
interior structures are destroyed ahead of exterior ones,
pulling the exterior walls toward the central axis
in a classic controlled demolition implosion.
Presumably the detonations throughout the interior or exterior
could be simultaneous,
or marched up the building as it sinks into its footprint.
Building 7 Compared to the Twin Towers
The destruction of Building 7 exhibited numerous tell-tale
signs of a conventional controlled demolition:
- The building sank into its footprint at near free-fall speed.
- The remarkably short rubble pile was mostly confined to the
building's footprint, with exterior wall sections lying on top.
- The destruction produced a cloud of dust with at least the volume
of the building.
The destruction of each of the Twin Towers differs
from a conventional demolition in several respects:
- The destruction proceeded from the top down
rather than from the bottom up.
- The time to complete destruction was about 50% longer
than free-fall time.
- The destruction was hidden behind a descending mushrooming cloud
of pulverized materials and metal pieces.
- The rubble pile was spread out, the vast majority of the fallout
lying outside the towers' footprints.
- The destruction produced a cloud of dust that continued
to grow after the last piece of steel hit the ground,
when it was already twice the volume of the building.
If the destruction of Building 7 is explainable as a conventional demolition,
then perhaps the different features of the Twin Towers' destruction
are explainable as modified controlled demolitions,
in which far greater quantities of explosives are used,
and the charges are set off in a top-down instead of bottom-up sequence
in order to simulate "progressive collapse" from the crash zones.
The main differences between the destruction of Building 7
(and conventional demolitions) and the destruction of the Twin Towers
can be summarized as follows:
- The Twin Towers were destroyed from the top down
instead of either from the bottom up or simultaneously throughout.
- The Twin Towers were destroyed much more thoroughly than
buildings destroyed by conventional demolition.
- The destruction of the Twin Towers killed over a thousand people.
Because of these differences,
most people less readily entertain controlled demolition of the Twin Towers
than they do of Building 7.
Ironically, the first two differences actually support a stronger case
for the controlled demolition of the Twin Towers than Building 7.
Their more thorough destruction required the input of more destructive energy,
and their top-down sequence of destruction meant that less mass was
available above the collapse zone to accomplish this greater
degree of destruction.
Computerized Demolition
The use of computers and radio links could greatly facilitate
the ease of deployment and operational flexibility
of a scheme employing numerous individual explosives
to destroy the towers from the crash zones downward.
Eric Hufschmid
has written about how such off-the-shelf technology
could be used in the controlled demolition of the towers.
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Packages of explosives could be installed on nearly every floor,
in the areas used by maintenance personnel.
...
Each package would have a battery powered radio link
that connected it to the main computer.
This master computer would be able to detonate specific packages
of explosives at specific times simply by sending signals to the packages.
...
After determining that the airplane hit the 77th floor of the South Tower,
the master computer would be set to detonate the explosives
on the 77th floor, and then 250 milliseconds later the explosives
on the 76th floor, then then 180 milliseconds later the explosives
on the 75th floor, etc.
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The scenario described by Hufschmid is not far-fetched.
While most controlled demolitions still use detonating cord
to set of the demolition charges,
technologies for the wireless detonation of explosives
are already commonplace.
For example,
HiEx.bc.ca
sells the TeleBlaster
"VHF or UHF telemetrey [sic] blast initiation system
intended for commercial blasting operations."
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Aluminothermics and Nano-Composites
Other means of designing the demolitions for ease of
covert deployment
could have involved the design of the explosives themselves.
For example, an explosive material that could be applied as a surface coating,
would remain stable for long periods of time,
and would be triggered only by
the very high temperatures emitted by their detonators,
would be ideal, particularly since even its application could be disguised
as perfectly innocent-looking fireproofing or primer coatings
applied like paint.
Perhaps surprisingly to people who don't follow military-funded
research at the U.S. national labs,
such materials have apparently existed for at least a decade,
in the form of high-tech
nano-structured aluminothermic composites.
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The amazing correlation between floors of impact and floors
of apparent failure suggests that spray-on nano-thermite materials may have
been applied to the steel components of the WTC buildings, underneath the
upgraded fireproofing (Ryan 2008).
This could have been done in such a way that
very few people knew what was happening.
The Port Authority's engineering consultant Buro Happold,
helping with evaluation of the fireproofing upgrades,
suggested the use of "alternative materials" (NIST 2005).
Such alternative materials
could have been spray-on nano-thermites substituted for intumescent
paint or Interchar-like fireproofing primers (NASA 2006).
It seems quite possible that this kind of substitution
could have been made with few people noticing.
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References
1.
The HiEx TeleBlaster II, HiEx.bc.ca,
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page last modified: 2009-04-18
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