BrianNZ wrote:
> It's a dig back at Hank/Henry who always insists that the 'magic' fires
> in the WTC buildings had no effect on their structural stability.
Of course, I never said any such thing. What I said is pretty
much the exact same thing all the experts in this paper say.
They say that random fires and asymmetric damage to a steel framed
building never has and never could cause a free fall speed and
symmetric collapse. Only a perfectly executed controlled demolition
can cause that. Your magic fire conspiracy theory violates the laws
of physics and contradicts all the hard evidence. Demolition satisfies
all the hard evidence and the laws of physics.
HTH
http://11syyskuu.blogspot.com/2006/0...-of-wtc-7.html
The Destruction of WTC 7
Latest updates:
5 Sept. 2006: NIST postpones its report until 2007, will consider if
explosions occurred
25 Sept. 2006: a demolition expert and two structural design
professors conclude WTC 7 was a controlled demolition
World Trade Center 7 was a steel-framed skyscraper completed in 1985.
It was located 110 meters (350 feet) away from the closest of the Twin
Towers. The building's tenants included the CIA, the U.S. Securities &
Exchange Commission, the Internal Revenue Service, several banks, and
the Mayor's Office of Emergency Management.
No airplane hit WTC-7, but its south facade and southwest corner were
damaged by debris ejected from the North Tower, which collapsed at
10.30 am. It was reported on fire at 4.10 pm by CNN, although the
fires seem to have started hours earlier, evidently before noon. The
fires were detected on a number of floors, and the building collapsed
at 5.20 pm.
A high-resolution video of the collapse is available here.
The Federal Emergency Management Agency, FEMA, speculated that office
fires caused the collapse of the building. It, however, acknowledged
in its report in May 2002: "The specifics of the fires in WTC 7 and
how they caused the building to collapse remain unknown at this time.
[...] the best hypothesis has only a low probability of occurrence."
Later in 2002, Larry Silverstein, the owner of WTC-7, gave in the
America Rebuilds TV program a famous "pull it" statement that has
generally been interpreted as meaning that the building was
professionally demolished.
Did WTC-7 collapse as a result of office fires, or was it demolished
with explosives? The answer can be sought by examining the way in
which the building collapsed.
Collapse Speed
As one can observe from the videos of WTC-7's collapse, shortly
following the destruction of its penthouse structures, the building
fell to the ground in 6.5 seconds. This is a phenomenally short time:
a stone dropped from the top of the building would have reached the
ground (covering a distance of 174 meters) in 5.95 seconds โ if there
were no air resistance! However, in principle the distance analyzed
should be that from the top of the building to the top of the debris
pile, not to the ground. As the exact height of the debris pile is not
documented, it is more useful to examine the early stages of the
collapse, during which the debris pile does not need to be taken into
account.
According to the video analysis presented in the 9-11 Eyewitness
documentary, starting from the state of rest, WTC-7 fell 100 meters in
4.5 seconds. This results in an acceleration of 9.8 m/s2,
corresponding to a free fall.
To verify this, I examined the fall of a corner of the building in one
collapse video using Blaze Media Pro video editing software. The
corner fell 56 meters (=the distance between the Start and End lines
in the picture below) in 3.47 seconds. This results in an acceleration
of 9.3 m/s2, which corresponds to a very low resistance factor of the
structural supports: only 5 percent of the force of gravity of the
building's falling upper section.
I also measured an acceleration of 8.5 m/s2 for the middle part of the
wide facade in the picture, which means that the force of resistance
of the structural supports was 13 percent of the force of gravity of
the falling upper section (see the calculation in more detail here).
My measurements therefore support the conclusion presented in 9-11
Eyewitness that the skyscraper fell virtually unimpeded. The lack of
structural resistance seems to be explainable only by the destruction
of the structural supports through the use of explosives.
WTC-7 fell on average 7 floors per second (47 / 6.5). One second after
the onset of the collapse, the speed of descent was almost 10
meters/second; after two seconds, almost 20 meters/second; and at the
end, about 60 meters/second (over 200 kilometers/hour).
Heikki Kurttila, a Finnish Doctor of Engineering and accident
researcher, has made detailed calculations about the collapse speed of
WTC-7. In his article Kurttila concludes that the short collapse time
and low structural resistance "strongly suggest controlled demolition".
Structural Features of the Collapse
A striking feature in the collapse of WTC-7 is symmetry. The collapse
progressed evenly throughout the building, and the debris piled up
almost entirely within the foundations of the building.
The symmetry of WTC-7's collapse means that all of its steel supports
โ 25 central and 58 peripheral columns โ were destroyed almost
simultaneously. Any asymmetry in the damage to structures would have
led to asymmetrical collapse. By contrast, a fully symmetrical
collapse without controlled use of explosives would not have followed
the principle of least resistance. Local fires could not have weakened
all the central and peripheral support structures in a way that would
have caused all of them to give up at the same moment.
A controlled demolition is also suggested by the drop of the center of
the skyscraper moments before the surrounding structures started to
fall, as well as by the fact that the outer walls were pulled inwards.
In a controlled demolition the collapse is caused by first destroying
the weight-carrying core of a building, which "pulls" the exterior
walls inwards ("implosion"). Although the lowest floor with fires was
reportedly the sixth floor, the building seems to have undergone a
traditional demolition, beginning from the bottom floor. An emergency
worker who witnessed the collapse of WTC-7 was interviewed on 9/11. He
described hearing what sounded like a "clap of thunder", followed by
what looked like "a shockwave ripping through the building", with
windows busting out, and "about a second later the bottom floor caved
out and the [rest of] the building followed after that".
At least one high-resolution video of the collapse of WTC-7 clearly
shows one more characteristic of controlled demolition: streamers of
dust emerging out of the building.
A Dutch demolition expert Danny Jowenko, who owns a demolition company
and has been in the business for 27 years, concluded in September 2006
that WTC 7 "is controlled demolition. [...] A team of experts did
this. This is professional work, without any doubt." Hugo Bachmann, a
Swiss professor emeritus for structural design and construction, said
in Tages-Anzeiger : "In my opinion WTC7 was with great probability
brought down by controlled demolition done by experts". In addition,
Jรถrg Schneider, another Swiss Professor emeritus for structural design
and construction, interprets the existing videos as indices that "WTC7
was with great probability brought down by explosives".
Fire Endurance of Steel
Steel is very fire-resistant material. In tests conducted by Chorus
Construction in several countries, the fire endurance of steel-framed
parking garages was examined by feeding fires with hydrocarbon fuel.
Steel beams and pillars heated to a maximum of 360 degrees Celsius,
and the breaking of steel was not even close. In Cardington fire
endurance tests non-fireproofed steel was subjected to temperatures of
up to 1150 degrees Celsius, but no collapse was observed. In the
Windsor Building in Madrid, a 24-hour intensive fire did not collapse
the building. Moreover, the fires in WTC-7 were insignificant compared
to fires in Windsor Building and all other skyscraper fires. Office
fires have never collapsed a single steel-framed highrise to the
ground. In the picture of WTC-7 to the right, the fires are limited to
small areas, almost all windows are intact, and no red heat indicative
of temperatures capable of softening steel is visible. The situation
is the same in other photographs taken of the building in late
afternoon. In this video a fair amount of smoke, but no flames, can be
seen. By contrast, WTC-5, which was badly damaged by the collapse of
the North Tower next to it, burned very powerfully: its floors were
covered by a sea of flames and all windows were broken. However, this
building, despite the fact that it had weaker support structures than
WTC-7, did not collapse into a debris pile, but remained standing.
Characteristics of the Debris
The debris of WTC-7 was extremely hot weeks after the collapse of the
building. Thermal imaging by NASA showed that the top of the debris
pile had a temperature of 730 degrees Celsius five days after the
collapse. Deeper, and immediately after the destruction, temperatures
were probably considerably higher. Residual temperatures like this
cannot be explained by office fires or by an ordinary, gravity-driven
collapse. When the potential energy of a building experiencing an
ordinary gravitational collapse turns into thermal energy, the result
is only a few degrees' average increase in temperature.
According to several reports, molten metal (also suggested by this
video footage) was found under the debris pile of WTC buildings. To
melt structural steel, temperatures exceeding 1500 degrees Celsius are
required. Such temperatures are never achieved in office fires. In
addition to molten metal, partly evaporated steel beams were found in
the debris of WTC-7. As professor Jonathan Barnett pointed out in a
New York Times interview, the fires in the building could not have
produced temperatures capable of evaporating steel. However, the use
of explosives like thermite can produce temperatures (even 3000
degrees Celsius) that can melt and even evaporate steel.
FEMA's investigators were not allowed to work in the collapse zone
itself. They were allowed to examine the debris of WTC skyscrapers
only in landfill areas used as temporary storage for the steel debris
before its recycling. By May 2005, when FEMA finished its preliminary
report calling for further investigation, all the steel debris had
been sold and shipped into the Far East. Only 156 pieces of steel were
chosen for futher analysis, of which a ridiculous total of 4 were from
WTC-7. Even these four no longer seem to exist.
As WTC-7 was evacuated over six hours before its destruction, there
were no grounds for the rapid removal and recycling of the steel
debris. Quite the contrary: as WTC-7 was one of the three greatest
building collapses in recorded history (the other two being the North
and South Towers), the debris of the building should have been
meticulously examined. Many individuals and publications, such as the
Fire Engineering Magazine, protested strongly against the rapid
destruction of the evidence.
Final Words
Was WTC-7 destroyed as a result of controlled demolition? Everyone can
draw their own conclusions from the way in which the building was
destroyed and the temperatures produced in the destruction.
If and when the building was demolished, it must have been wired with
explosives before September 11th. An operation of that magnitude could
not have been accomplished during a couple of chaotic hours. This is
why the official hypotheses have not touched on the most obvious
explanation for the collapse of the skyscraper. It is revealing that
the 9/11 Commission, which published its report in 2004, does not
mention in a single sentence the destruction of the third skyscraper
resulting from the terrorist attack in New York.
FEMA's work has been continued by the National Institute of Standards
and Technology, which has again postponed its report on WTC-7, this
time until 2007. NIST is now saying that it is also investigating the
hypothesis that explosions initiated the collapse. Interviewed in the
March 2006 issue of New York Magazine, Dr S. Shyam Sunder, NIST lead
investigator, summed up the present state of the investigation:
NIST did have "some preliminary hypotheses" on 7 WTC, Dr. Sunder said.
"We are studying the horizontal movement east to west, internal to the
structure, on the fifth to seventh floors." Then Dr. Sunder paused.
"But truthfully, I don't really know. We've had trouble getting a
handle on Building No. 7."
--
http://911research.wtc7.net http://www.st911.org
Here's what happens to steel framed buildings exposed
to raging infernos for hours on end.
http://davesweb.cnchost.com/nwsltr69c.html
On 9-11-01, WTC7, a 47 story steel framed building, which
had only small, random fires, dropped in perfect symmetry
at near free fall speed as in a perfectly executed controlled
demolition.
http://911research.wtc7.net/talks/wtc/videos.html http://www.physics.byu.edu/research/energy/htm7.html http://wtc7.net/articles/FEMA/WTC_ch5.htm
"You're doin' a heckuva job, Brownie!" - bu$h, a few days
before his FEMA chief, Micheal Brown was forced to resign
because of his gross incompetence.
"The tools that enable Cuba to save lives and preserve
human dignity during hurricanes are socialist values
and organization." - Dr. W.T. Whitney Jr
Ever wonder who benefits from the 300 MILLION
U.S. taxpayer dollars spent each DAY in Iraq?
http://www.commondreams.org/views04/0223-08.htm http://www.corpwatch.org/article.php?list=type&type=21
"They are waging a campaign of murder and destruction. And
there is no limit to the innocent lives they are willing to
take... men with blind hatred and armed with lethal weapons
who are capable of any atrocity... they respect no laws of
warfare or morality."
-bu$h describing his own illegal invasion of Iraq.
http://www.robert-fisk.com/iraqwarvictims_mar2003.htm http://www.commondreams.org/ http://www.truthout.org/ http://www.prohibitioncosts.org/ http://thirdworldtraveler.com/ http://counterpunch.org/ http://responsiblewealth.org/
"Our lives begin to end the day we become silent about things
that matter." -- Martin Luther King Jr.
"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong, is
not only unpatriotic and servile, but is morally treasonable
to the American public."
-- Theodore Roosevelt (1918)
Don't let bu$h do to the United States what his very close
friend and top campaign contributor, Ken Lay, did to Enron...
Re: It's gym time, Hank. (was Re: Conspiracy theorists do not think logically) 
