Dan wrote in news:HX2Sf.61662$Ug4.7991@dukeread12:
TRUTH wrote:
"Keith W" wrote in
:
"Wake Up!" wrote in message
...
"Keith W" wrote in
:
The behaviour of steel in fire hasnt changed in 60 years and yes
they were complete collapses
I can cite other cases, the Hotel York in Redcar England was
a 15 storey steel framed hotel that collapsed after a fire
for example
Based on the following quote from Jones' paper, it can be assumed
that the collapses you mention above are not relevant to the
current situation:
No they are vidence of how full of **** Jones is.
A New York Times article entitled “Engineers are baffled over the
collapse of 7 WTC; Steel members have been partly evaporated,”
provides relevant data.
Experts said no building like it [WTC7], a modern, steel-reinforced
high-rise, had ever collapsed because of an uncontrolled fire.
(Glanz, 2001; emphasis added.)
And they were wrong
Fire engineering expert Norman Glover agrees:
Almost all large buildings will be the location for a
major fire in their useful life. No major high-rise
building has ever collapsed from fire…
The WTC [itself] was the location for such a fire in
1975; however, the building survived with minor damage
and was repaired and returned to service.” (Glover,
2002)
That fire was confined to approx half of a single floor rather than
several floors and the building had not been damaged by a
major impact.
That makes a difference
That’s correct – no steel-beam high-rise had ever before (or since)
completely collapsed due to fires!
Incorrect, I have given examples that you choose to ignore
However, such complete and nearly
symmetrical collapses in tall steel-frame buildings have occurred
many times before -- all of them due to pre-positioned explosives
in a procedure called “implosion” or controlled demolition.
Which requires weeks of careful preparation by large work teams,
none of whom were in evidence at the WTC
snip
The Towers' implosions were not typical. They were detonated top
down. Therefore, any engineer truncating the investigation at
collapse initiation will not see the evidence.
You dont use explsoives to demolish buildings from the top
down, you blow out the lower floors and some intermediate
floors in a timed sequence
Except when demolishing unique structures like the Twin Towers.
Besides, the government couldn't make controlled demolitions *too*
obvious
You never did answer my question: how did they hide the
preparations
required for a controlled demolition? Where did they put all the
debris they would have had to remove in preparation? How come no one
noticed a daily line of dump trucks hauling away the debris? Remember
walls, windows, and structural members are always removed in
preparation for controlled demolitions. What about all the structural
members that had to be weakened with torch cuts? How about the several
thousands of feet of det cord and charges placed in plain view? It
would have taken weeks and much manpower just to prepare the
buildings. How come no one noticed? Why do you keep refusing to
answer?
The only info I have is the power down in the South Tower:
http://69.28.73.17/thornarticles/powerdown.html
http://killtown.blogspot.com/2005/12...interview.html
Also, GWB's brother Marvin, and a cousin were executives in the WTC's
security company
By your tone / name calling, you sound a bit upset. Perhaps because
you think there's something to Jones' claims afterall? I noticed you
snipped out one of Jones' main points from my response, regarding
NIST not performing analysis after collapse inituation.
You have a history of name calling yourself.
Only in direct retaliation.
Why would NIST need to
do an analysis after initiation of collapse when they already proved
what how it started? It was simply a chain reaction.
Dan, U.S. Air Force, retired
Perhaps to learn clues to prevent a complete, freefall "fire induced"
collapse from happening again, especially since:
It never happened before, but on 9/11 it happened three times. An
executive in the WTC Management said in his opinion the Towers could
withstand multiple 707 impacts, and compared it to a pencil puncturing a
screen netting. Firefighters made it up to the impact area of the South
Tower and suggested nothing major.
Also, are you aware that NIST literally "changed" the data in their
computer simulation to get the Towers to collapse? And now they refuse to
show the simulations to leading fire engineers who call for them.
From Jones' paper:
http://www.physics.byu.edu/research/energy/htm7.html
The NIST report makes for interesting reading. The less severe cases
based on empirical data were discarded because they did not result in
building collapse. But ‘one must save the hypothesis,’ so more severe
cases were tried and the simulations tweaked, as we read in the NIST
report:
The more severe case (which became Case B for WTC 1 and Case D for WTC 2)
was used for the global analysis of each tower. Complete sets of
simulations were then performed for Cases B and D. To the extent that the
simulations deviated from the photographic evidence or eyewitness reports
[e.g., complete collapse occurred], the investigators adjusted the input,
but only within the range of physical reality. Thus, for instance,…the
pulling forces on the perimeter columns by the sagging floors were
adjusted... (NIST, 2005, p. 142; emphasis added.)
The primary role of the floors in the collapse of the towers was to
provide inward pull forces that induced inward bowing of perimeter
columns. (NIST, 2005, p. 180; emphasis added.)
How fun (perhaps) to tweak the model like that, until the building
collapses -- until one gets the desired result. But the end result of
such tweaked computer hypotheticals is not compelling, sorry gentlemen.
Notice that the “the pulling forces on the perimeter columns by the
sagging floors were adjusted” (NIST, 2005, p. 142; emphasis added) to get
the perimeter columns to yield sufficiently – one suspects these were
“adjusted” by hand quite a bit -- even though the UK experts complained
that “the core columns cannot pull the exterior [i.e., perimeter] columns
in via the floor.” (Lane and Lamont, 2005; emphasis added.)
I also agree with Kevin Ryan’s objections regarding the NIST study.
Kevin Ryan, at the time a manager at Underwriters Laboratories (UL),
makes a point of the non-collapse of actual WTC-based models in his
letter to Frank Gayle of NIST:
As I'm sure you know, the company I work for certified the steel
components used in the construction of the WTC buildings. In requesting
information from both our CEO and Fire Protection business manager last
year… they suggested we all be patient and understand that UL was working
with your team… I'm aware of UL's attempts to help, including performing
tests on models of the floor assemblies. But the results of these tests…
indicate that the buildings should have easily withstood the thermal
stress caused by… burning [jet fuel, paper, etc.]. (Ryan, 2004)
That models of WTC trusses at Underwriter Laboratories (UL) subjected to
fires did NOT fail is also admitted in the final NIST report:
NIST contracted with Underwriters Laboratories, Inc. to conduct tests to
obtain information on the fire endurance of trusses like those in the WTC
towers…. All four test specimens sustained the maximum design load for
approximately 2 hours without collapsing… The Investigation Team was
cautious about using these results directly in the formulation of
collapse hypotheses. In addition to the scaling issues raised by the test
results, the fires in the towers on September 11, and the resulting
exposure of the floor systems, were substantially different from the
conditions in the test furnaces. Nonetheless, the [empirical test]
results established that this type of assembly was capable of sustaining
a large gravity load, without collapsing, for a substantial period of
time relative to the duration of the fires in any given location on
September 11. (NIST, 2005, p. 141; emphasis added.)
So how does the NIST team justify the WTC collapses, when actual models
fail to collapse and there are zero examples of fire-caused high-rise
collapses? Easy, NIST concocted computer-generated hypotheticals for
very “severe” cases, called cases B and D (NIST, 2005, pp. 124-138). Of
course, the details are rather hidden to us. And they omit consideration
of the complete, rapid and symmetrical nature of the collapses.
Indeed, NIST makes the startling admission in a footnote on page 80 of
their Final Report:
The focus of the Investigation was on the sequence of events from the
instant of aircraft impact to the initiation of collapse for each tower.
For brevity in this report, this sequence is referred to as the "probable
collapse sequence," although it does not actually include the structural
behavior of the tower after the conditions for collapse initiation were
reached...(NIST, 2005, p. 80, fn. 12; emphasis added.)
Again, on page 142, NIST admits that their computer simulation only
proceeds until the building is “poised for collapse”, thus ignoring any
data from that time on.
The results were a simulation of the structural deterioration of each
tower from the time of aircraft impact to the time at which the building
became unstable, i.e., was poised for collapse. ...(NIST, 2005, p. 142;
emphasis added.)
What about the subsequent complete, rapid and symmetrical collapse of the
buildings? What about the observed squibs? What about the antenna
dropping first in the North Tower? What about the molten metal observed
in the basement areas in large pools in both Towers and WTC 7 as well?
Never mind all that: NIST did not discuss at all any data after the
buildings were “poised for collapse.” Well, some of us want to look at
ALL the data, without computer simulations that are “adjusted,” perhaps
to make them fit the desired outcome. An hypothesis which is non-
refutable is non-scientific. On the other hand, Occam's razor suggests
that the simplest explanation which addresses and satisfies ALL the
evidence is most probably correct.
14. Support from New Civil Engineering Article
An article in the journal New Civil Engineering (NCE) has
come to my attention at the end of the draft-process which lends support
to concerns about the NIST analysis of the WTC collapses. It states:
World Trade Center disaster investigators [at NIST] are refusing to
show computer visualizations of the collapse of the Twin Towers despite
calls from leading structural and fire engineers, NCE has learned.
Visualisations of collapse mechanisms are routinely used to validate the
type of finite element analysis model used by the [NIST] investigators.
The collapse mechanism and the role played by the hat truss at the top of
the tower has been the focus of debate since the US National Institute of
Standards & Technology (NIST) published its findings….
University of Manchester [U.K.] professor of structural engineering Colin
Bailey said there was a lot to be gained from visualising the structural
response. “NIST should really show the visualisations; otherwise the
opportunity to correlate them back to the video evidence and identify any
errors in the modeling will be lost,” he said….
A leading US structural engineer said NIST had obviously devoted enormous
resources to the development of the impact and fire models. “By
comparison the global structural model is not as sophisticated,” he said.
“The software used [by NIST] has been pushed to new limits, and there
have been a lot of simplifications, extrapolations and judgment calls.”
(Parker, 2005; emphasis added.)
Here we have serious concerns about the NIST WTC collapse report raised
by structural and fire engineers, augmenting the arguments raised here by
a physicist.