Conspiracy Theorists bring up the fact that the towers
were the first steel high rises to fall from fire in history. The fact is the towers
had other firsts that day they never seem to include.
There were a lot of firsts for the WTC. In all the history
of high-rise fires, not one has ever been hit with a plane traveling 500 miles
an hour and had its fire proofing removed from its trusses. In all the history
of high-rise fires, not one has ever had its steel columns which hold lateral
load sheared off by a 767. In all the history of high-rise fires, not one has
ever been a building which had its vertical load bearing columns in its core
removed by an airliner. For Building 7, in all the history of high-rise fires,
not one has ever been left for 6-7 hours with its bottom floors on fire with
structural damage from another building collapse. Not
the Madrid/Windsor tower did not have almost 40 stories of load on its supports
after being hit by another building which left a 20 story gash.
The Madrid tower lost portions of its steel frame from the
fire. Windsor's central core was steel reinforced concrete. In
all the history of high-rise fires, not one has ever been without some fire
fighters fighting the fires.
I could go on with the "Firsts" but you get the drift. The
statement that the WTC buildings were the first high-rise buildings to collapse
from fire is deceptive because it purposely doesn't take those factors into
account.
Conspiracy sites point to the building falling straight down as proof the buildings were blown
up. Even Professor Jones uses this in his paper as an indication of
controlled demolition.
But Jones and others making this
claim know very well that these buildings are not built like the towers. Most
of the buildings they point to are steel reinforced concrete buildings
or have steel reinforced concrete cores.
Others are constructed with a steel web evenly distributed throughout
the building. These buildings are not a "tube in a tube" design. The
towers were steel without concrete. The towers perimeter steel walls
were held in place by the trusses and those trusses were connected to
the perimeter columns by small bolts. They also weren't hit by an
airliner at 500 miles an hour. While it's true they were designed to
withstand the impact of a smaller 707, they never factored
in the removal of fire proofing or fuel in the wings.
"It is
impressive that the World Trade Center towers held
up as long as they did after being attacked at full
speed by Boeing 767 jets, because they were only
designed to withstand a crash from the largest plane
at the time: the smaller, slower Boeing 707. And
according to Robertson, the 707's fuel load was not
even considered at the time. Engineers hope that
answering the question of exactly why these towers
collapsed will help engineers make even safer
skyscrapers in the future. ASCE will file its final
report soon, and NIST has been asked to conduct a
much broader investigation into the buildings'
collapse."
But it
wasn't the impact which the NIST said brought the building
down. That's a conspiracy theorist straw man. They show an
interview with a construction manager who said the buildings
steel skin should have held up by redistributing the load.
He's right. This is EXACTLY what the NIST said happened. It
wasn't the impact alone which the NIST said brought down the
towers. It was a combination of factors. The only way
conspiracy theorists can attack the report is by separating
these factors and attacking them individually. It's like
taking a car accident apart and saying the car shouldn't
have skidded off the road because the factory said the car
could grip up to .97 g's. While that might be true, the
conditions on the road must be factored in. Was there rain,
dirt, gravel, anything which could have contributed to the crash?
Conspiracy theorists are engaged in deliberate disinformation
when they talk about these factors in a vacuum. They KNOW
these factors can't be separated.
The PBS special did a good job of
explaining the difference between the towers construction and these
other buildings conspiracy theorists like to point to. Most steel
buildings have a web of steel like this...
The towers had most of the steel in
this web on its skin to save office space. Like this...
Note: What's missing
from the above photo are the core columns but they are not
needed to show the difference in building construction.
Conspiracy theorists will be quick to point out
this photo doesn't show the core columns but
this isn't here to show how many stick figures
someone can create. It's here to show how the
building had a vastly different design than the
average building. If you're a conspiracy
theorist just imagine your 47 box columns in the
core. (The dark area in the center) The building will still be built
differently, box columns in this image or not. http://www.pbs.org/wgbh/nova/wtc/collapse.html
The towers and building
7 were essentially bolted together like an erector set. No concrete was
used to create a ridged block or protect the columns. The steel webbing
was pushed to the outer walls.
A challenge to
conspiracy theorists:
1) Find a steel
frame building at least 40 stories high
2) Which takes
up a whole city block
3) And is a "Tube
in a tube" design
4) Which came
off its core columns at the bottom floors (Earthquake, fire,
whatever - WTC 7)
5) Which was
struck by another building or airliner and had structural damage
as a result.
6) And weakened
by fire for over 6 hours
7) And had
trusses that were bolted on with two 5/8" bolts.
And which, after all seven
tests are met, the building does not fall down. Anyone dissecting this into
7 separate events is lying to you.
Anything less than
meeting these seven tests is dishonest because it's not comparing apples
with apples. Showing a much lighter 4, 5 or even 15 story building which
doesn't even take up a city block, and has an old style steel web design
leaves out the massive weight the 47 story WTC 7 had bearing down on
its south face columns. Yes, this is "moving the bar", back to where it
should have started.
It is an absurdity to
expect these buildings to perform the same during a collapse. This is
why it's the first time in history these buildings fell as they did.
It's the first time in history buildings constructed like this
collapsed.
Update:
Conspiracy theorists say the Deutsche Bank fire is
more proof that steel buildings do not collapse by fire. But once again
they fail to compare apples with apples.
1) The building was NOT a tube in a tube design. It was a web design
which disperses load more evenly.
2) The fires were on the upper floors. The fire affected steel did not
have anywhere near the same weight on them as the WTC7.
3) The towers had it's fireproofing removed by the impact of the
airliners. Not so for the Deutsche Bank.
4) The fires were being fought which is why 2 firemen died.
6) There was no Con Ed substation to build the core columns around as
with the WTC 7.
7) Those steel beams already had floors removed above them. The steel
started with a lighter load before the fire.
8) The Deutsche Bank did not have 6000 gal of oil
stored in the building as WTC 7 did.
Those are just some reasons the events are very
different.
Contrary to popular belief September
11, 2001 was not the first time
a steel framed building collapsed due to fire. Though the examples below
are not high rise buildings, they make the point that fire alone can
collapse a steel structure.
The McCormick Center in Chicago and the Sight and
Sound Theater in Pennsylvania are examples of steel structures
collapsing. The theater was fire protected using
drywall and spray on material. A high rise in Philly didn't collapse
after a long fire but firefighters evacuated the building when a
pancake structural collapse was considered likely. Other steel-framed buildings partially collapsed due fires one after only 20
minutes.
The steel framed McCormick Center was at the time the World's
largest exhibition center. It like the WTC used long steel trusses to create a large open space without columns. Those trusses were
unprotected but of course much of the WTC lost it's fire protection
due to the impacts.
"As an example of the damaging effect of fire on steel, in 1967, the
original heavy steel-constructed McCormick Place exhibition hall in
Chicago collapsed only 30 minutes after the start of a small
electrical fire."
The McCormick Place fire "is significant because it illustrates the
fact that steel-frame buildings can collapse as a result of exposure
to fire. This is true for all types of construction materials, not
only steel." wrote Robert Berhinig, associate manager of UL's Fire
Protection Division and a registered professional engineer. He also
discusses UL's steel fire certification much more knowledgably than
Kevin Ryan. He is an example of one more highly qualified engineer
who supports the collapse theory.
On the morning of January 28, 1997, in the Lancaster County,
Pennsylvania township of Strasburg, a fire caused the collapse of
the state-of-the-art, seven year old Sight and Sound Theater and
resulted in structural damage to most of the connecting buildings. The theater was a total loss, valued at over $15 million.
pg 6/74
The theater was built of steel rigid frame construction to allow for
the large open space of the auditorium, unobstructed by columns...
The interior finish in the auditorium was drywall.
The stage storage area, prop assembly building, and prop maintenance
building were protected with a sprayed-on fire resistant coating on
all structural steel. The plans called for the coating to meet a two-hour fire resistance assembly rating. The sprayed-on coating, which
was susceptible to damage from the movement of theater equipment,
was protected by attaching plywood coverings on the columns to a
height of eight feet.
The walls of the storage area beneath the stage were layered drywall
to provide a two-hour fire protection rating for the mezzanine
offices [the WTC used drywall as fire protection in the central
core] , and sprayed-on fire-resistant coatings on the structural steel columns and ceiling bar joists supporting the stage floor. pg 15/74
The two theater employees told the State Police Fire Investigator
that when they first discovered the fire they noticed that the
sprayed-on fire proofing had been knocked off the underside of the
stage floor bar joists and support steel. The fire proofing was
hanging on the wire mesh used to hold the coating to the overhead.
The investigation revealed that the construction company's removal
of the stage floor covering down to the corrugated decking involved
striking the floor hard enough to knock off the sprayed-on
protection, exposing the structural steel and bar-joists in the
storage area. [The theater's spray-on fireproofing was newer and more
modern than at the WTC, The theater was only seven years old. If
striking the floor during renovations was enough to dislodge it
imagine the impact of a 767]
pg 16/74
Temperatures of 1000° F can cause buckling and temperatures of 1500°
F can cause steel to lose strength and collapse. When the heat and
hot gases reached the stage ceiling they extended horizontally into
the auditorium, causing the roof to fail all the way to the lobby
fire wall. The fire also extended horizontally from the stage to the
elevated hallway, causing the structural steel to fail and buckle in
the prop assembly and prop maintenance buildings
pg 17/74
Once the heat of the fire caused the structural steel to fail in the
storage area (aided by the damage to the sprayed-on fire protection
during renovation), interior firefighting became too hazardous to
continue. The truck crews ventilating the roof noted metal discoloration and buckling steel.
pg. 21/74
The two hour fire resistance-rated assembly in the storage area
beneath the stage was damaged during the stage floor renovation,
leaving the structural members unprotected from the ensuing fire.
pg. 26/74
Buildings constructed of steel should, in effect, be considered
unprotected and capable of collapse from fire in as few as ten
minutes. Fire resistant coatings sprayed onto structural steel are
susceptible to damage from construction work.
The impact of fire and heat on structural steel members warrant
extreme caution by firefighters.
pg. 36/74 Unless the steel members are cooled with high-volume hose streams,
the fire's heat can rapidly cause steel to lose its strength and
contribute to building collapse. pg. 37/74
Other Fires
In February 1991, a fire broke out in One Meridian Plaza
- a 38 story
office building in Philadelphia. The building was built during the
same period as the WTC and had spray-on fire protection on its
steel frame. Despite not suffering impact damage, authorities were
worried it might collapse.
"All interior firefighting efforts were halted after almost 11 hours
of uninterrupted fire in the building. Consultation with a
structural engineer and structural damage observed by units
operating in the building led to the belief that there was a possibility of a pancake structural collapse of the fire damaged
floors."
About 2 years later, the NYFD was concerned that a steel framed
building that partially collapsed during after a gas explosion might
collapse
entirely due to the resulting fire.
