No one is denying that the force of a cap falling would be enough to break the connections and buckle the beams of the first floor beneath, and many
beyond it. This is a convenient strawman. As an aside, I get about 385kg (0.385t) of TNT of kinetic energy for a 45,000t cap in freefall across 12
feet. While this is moot in a way because that's still a lot of energy, if I'm right it shows yet again that Eagar is either careless/sloppy/wrong
in his calculations, or he has upped the figure to half a ton because it sounds more convincing. Furthermore the kinetic energy figure assumes that
the cap was in free fall and zero negative impulse was provided by the columns as they buckled. Last time I checked, the official story states that
the collapse did NOT occur in freefall, so why then go ahead and use freefall speed to calculate the kinetic energy?
But anyway, that's not where the problems lie with the collapses. The problems lie in:
1) The alleged severity of the fires and their ability to weaken all of the supports enough to initiate a collapse in the first place, despite the
enormous redundancy of the structure, and despite the physical evidence showing that the steel did not experience temperature excursions above
2) The perfect symmetry and synchronicity of the collapse initiation at all 283 support points on one single floor, despite asymmetrical fires and
3) The symmetry of the ensuing collapse thereby following the path of MOST resistance in direct violation of basic physics and plain old intuition.
4) The speed of the collapse implying little to no resistance from the structure beneath.
5) The apparent lack of any retardation to the collapse acceleration as would be expected from the progressively stronger supports towards the
6) The inconsistency of the observed disintegration of the caps and ejection of debris when reconciled with the pancake increasing-mass theory.
7) The observation of two completely separate events in the collapse, being a) The destruction waves running down the side of the buildings, and b)
the collapse itself many floors above.
8) The lateral ejection of huge portions of debris by also necessarily huge impulses at a complete 90° angle to the vertical vectored forces
9) The total pulverization of the concrete, the desks, the telephones, the computers and everything else into clouds of nano-dust, even right at the
beginning of the collapse when the kinetic energy build-up was relatively low and the floors were bumping into each other at 18mph, and further
despite the inefficiency of vertical steel "spears" on the central interior and on the perimeter as a grinding mechanism.
10) The massive overpressure created tens of floors below the collapse zone exploding pulverized debris out of isolated areas, despite the destruction
of the "syringe" walls allowing air to escape sideways, despite the destruction of the "piston" allowing air to escape up, despite the severely
constricted nature of the HVAC and stairwell system thus inhibiting their ability to convey pressure, and despite the fact that a generalized large
overpressure across a single floor would blow out multiple windows or all of them and not just in a single location.
45,000 tonnes of cap can't seem to explain these anomalies, and so the debate continues. In fact a billion tonnes of cap couldn't explain them,
because the heavier the cap is, the stronger the building below is. So cursing and fussing over the weight of the building is largely moot for these
considerations. And this is simply addressing the tower collapses. Bring WTC7 into the mix and whoa baby, some major problems with the official story.
Add in some molten steel for spicing and the official broth is starting to taste mighty bitter. And if we want to get into the prior knowledge and
NORAD stand-down side of things, then we'll be here for 4 years..oh wait, we already have been.
The blasts down the sides of the buildings, separate to the actual collapses, progressed at a constant rate (and in perfect confluence). Here watch
these videos of you don't believe me:
This completely defies basic physics concepts. When something is being acted upon by gravity, if gravity is stronger than any resisting force, the
object will accelerate downwards. If gravity is weaker than any resisting force, the object will decelerate. In a carefully controlled event, like say
an elevator's descent/ascent, this is achievable. But in a natural event, only if by some freak of probability/nature gravity is perfectly balanced
by another force will a falling object maintain constant velocity. Now if we're going to assume that each floor encountered by the falling mass
somehow provided the exact amount of resistance required to balance gravity once the first floor was in motion, then the time for the collapse of each
floor is constant, hence the total time of collapse would have been 98 floors times the time it took for the first floor to fall. 98 floors x 0.864s
(0 - 12 feet in freefall, discounting any air resistance and impulse from buckling columns) = 95.04s. We come to such a ridiculous figure because,
again, the constant-velocity destruction of the floors is itself impossible for a natural, gravity-driven event. Only if the floors were blown in a
human-controlled sequence could we get such a phenomenon occurring, in which case the floors could be destroyed 0.03 seconds apart, or whatever you
want. The official story hinges on gravity being unbalanced in the system, in which case the pancaking should have accelerated. But it didn't, it
maintained a constant velocity. And even more damning is the clearly observable fact that what has been described as "pancaking" and looks a heck of
a lot more like explosions, was thirty plus stories ahead of the actual collapse zone above.
The official story also hinges on the floors pancaking as one, but watch any clear video (some of the ones I linked above will show it) and you'll
see that the destruction waves which race down the sides of the structures at a constant rate leave the corners of the structure perfectly intact. The
waves run down the flat sides of the structure, but the corners are still intact 25 or more storeys above. This can not be reconciled with the pancake
Assessing how much resistance each floor would have provided is a mammoth and nigh-impossible task, and is far, far beyond my meager abilities, I'm
certainly no physicist, and it's beyond the abilities of anyone here I'll wager, except maybe LaBTop. Maybe MacMerdin working together with a
physicist could carry off an estimation. The complexity arises from needing to know the exact details of all the connections, the vertical columns,
the bracing beams, the floor pans, the bolts, and on it goes; details including dimensions, assembly type, material grades, and variations across the
height and different locations in the structure. From there after a few months of work, maybe one could estimate the forces required to break all the
connections and buckle columns. But then once you get into the actual collapse, you'd need to guess the types of forces acting on each connection,
column, beam, floor pan, etc. The ability of a component to resist stress depends on the type of stress acting on it, be it shear, buckling, tension,
torsion, compression, or whatever combination of each. Ask MacMerdin if this ain't so. A column compressed from above will behave differently to,
say, a column struck from the side, or with its top bending left and its bottom bending right. In a system as large and random as the collapse of the
towers with all those millions of pieces all behaving differently and colliding with different components, there is no feasible way to calculate all
those micro-interactions and apply them to a macro assessment, short of a dedicated computer model with years of research, teams of researchers, and
millions of dollars invested in it. NIST has these resources, and they didn't touch the collapses. Funny, huh?
That's why focusing on macro events are the only reasonable way to assess the physics of the collapses. For an example, something we can do is look
at it from a simple conservation of momentum point of view. Assume a model where each floor was a flat slab simply floating in space, held up by a
magical forcefield that turned off as soon as anything touched it. Hence, when each floor collided with the next one below, that floor gave way
without any resistance at all. Assume the collisions are perfectly inelastic. In this bizarre example, the only thing slowing the collapse is the
momentum imparted to each floor below by the ever-increasing falling mass. Conservation of momentum tells us that the momentum after the collision is
the same as before, and since p = mv, with momentum, mass, and acceleration due to gravity known, we can calculate the new velocity after each
collision, after each 12 foot free fall, and hence the total time for collapse. Using Eagar's figures for the building and cap mass of 500,000t and
45,000t respectively, and assuming an increase in floor mass in increments across the three sections of the building, I get 13.05 seconds. Further
assuming that 30% of the mass of each struck floor (but not the cap) falls off the side, that brings the collapse time up to 14.08 seconds (30% is
quite conservative when you consider the 236 steel columns supporting 50% of the vertical load were on the skin of the building which was thrown out
all over Manhattan, when you look at debris distribution in the satellite pics taken after the event, and when you consider I didn't subtract
anything off the 45,000t cap). So, that's at least 14.08 seconds assuming the structure provided ABSOLUTELY ZERO RESISTANCE and ALSO discounting air
resistance which bob2000 insists would have a significant effect. Do the math yourself and tell me if I'm wrong, my math sucks so I could well be. I
don't have time to lay it all out here, but if anyone wants to check my math instead of doing their own, U2U me your email and I'll send the xls
file to you.
14 seconds with ZERO structural resistance. Uber-brains like Thomas Eagar with his 10 second
collapse time SHOULD KNOW THIS, so we can only
assume one of four things:
1. My maths is wrong (possible, so someone please do check it).
2. Eagar and his ilk are idiots (highly unlikely, at least from a mathematical point of view).
3. Eagar and his ilk haven't done any serious assessment and are simply shooting the official story off from the hip (seems most likely, considering
Eagar is extremely busy, he was not contracted to research the collapses, contrary to popular misconception he is NOT a structural engineer, and
lastly his primary academic focus is obscure welding techniques).
4. Eagar and his ilk, for whatever reason, are deliberately obfuscating the facts (seems impossible, but Eagar's constant mistakes and his consistent
misrepresentations of the structural details are truly hard to reconcile with his intelligence, expertise, and status).
Notice, if you will, how the people who AREN'T shooting from the hip to simply shore up the holes in the official story, but rather are responsible
for creating it, i.e. FEMA and NIST, have NEVER addressed the physics or causes of the total collapses beyond their initiation. AND their conclusion
for the cause of the initiation was arrived at by computer simulations that are CLEARLY contradicted by the real-world, physical evidence. The best
NIST provided to explain the history-making, unprecedented complete collapse down to the very pavement of two steel skyscrapers in 10 - 15 seconds,
was once single sentence: "Global collapse then ensued." Am I the only one who finds this to be just crazy?? Never before has anything like this
happened in the history of mankind. It then happens three times in one day while the entire world is watching, and THEY DON'T EVEN TRY TO EXPLAIN IT
OR STUDY IT?!
But I don't know why we discuss the "global collapses" so much when the conditions alleged to have brought about the collapse initiation
the first place are directly contradicted by the physical evidence. The fires were dying. Steel cools and regains its strength. If the buildings
didn't collapse at the height of the fires, then they were never going to collapse. Check the metallurgical tests NIST did on the steel, check the
location of those columns tested, and then compare it with their 1100°C computer simulations and you'll see that they simply DO NOT MATCH UP
I'm busy with major RL stuff and don't have the time to pull out all the images and so forth, but it's all there in the NIST reports for everyone
to see if you really want to.
You can find the testing methods and results here: wtc.nist.gov...
The tested component locations are tabulated in Appendix E here: wtc.nist.gov...
And then you can compare it to the fire computer simulations here: wtc.nist.gov...
In addition to this bald-faced deception, rarely mentioned is the 1975 fire in WTC1:
On February 13, 1975, a fire, set by a custodian turned arsonist, started on the 11th floor and spread to limited portions of six other floors,
burning for three hours. Several fire suppression systems that were later installed in the towers were not present at the time, including sprinklers,
elevator shaft dampers, and electrical system fireproofing.
The fire, which broke out just before midnight, did not kill anyone but forced the evacuation of fifty people, consisting mostly of maintenance staff.
The captain of Engine Co. 6 described the suppression effort as "like fighting a blow torch."
A three hour "blow-torch" fire and the building doesn't give a murmur or a creak. Nobody expected the building to collapse because no steel-framed
building had ever done so until 9-11. Sure, it didn't have a jet liner crash into it, but it was also the 11th floor, supporting nearly 100 floors of
weight above it, which is consistently the reason given as to why the South tower collapsed first. By comparison, the 2001 collapsed of WTC1 initiated
at the 98th floor, with only 12 floors above it. The redundancy of the structure compensated for the jet impacts, as evidenced by the fact that they
stood with barely a sway after the impacts, so all that was left to collapse the buildings - by NIST's own admission - was the fires. The jet fuel
burned off in the first 15 minutes, also by NIST's admission, so that leaves the office furniture to create these alleged super-hot fires. But the
fires weren't hot enough to heat the steel to even 250°C as shown by the physical evidence, whereas steel needs to reach 600°C before it will begin
to show plastic yield...aaaaaand it seems we're back to square one with collapse impossible. You see where I'm going with this? There's a hole in
the frikkin' bucket, dear Liza, well fix it dear Henry, and round it goes all the way back to the hole in the bucket.
Remember the guy from Canada's Underwriter Laboratories who blew the whistle on the NIST tests? Now have a look at what Fire Engineering institutes
in the UK have to say about the effects of steel and temperatures on steel structures. These guys built actual structures and then set them on fire,
instead of simply heating beams in an oven like NIST:
Cardington fire tests
The tests were carried out to determine if the fire performance of real buildings of this type is better than is suggested by tests on individual
elements of construction. Evidence that this is the case had been provided by studies of actual fires in real buildings, such as the
Investigation of Broadgate Phase 8 Fire, published by the Steel Construction Institute; tests carried out by BHP in Melbourne in Australia and also
small scale fire tests and computer modeling of structural behavior. In all these cases, composite floors had demonstrated robustness and
resistance to fire far greater than was indicated by tests on single beams or slabs.
In order to determine a direct comparison, the first test was carried out on a single unprotected beam and surrounding area of slab. The results
demonstrated that a failure deflection (normally considered to be Length/30) would have occurred at approximately 1000°C, far greater than the
temperature of 700°C at which the beam would have failed if tested in isolation.
Further tests were carried out in compartments varying in size from 50m.sq. to 340m.sq. with fire loading provided by gas, wooden cribs or standard
office furniture. Columns were protected but beams were not. However, despite atmosphere temperatures of almost 1200°C and steel temperatures on
the unprotected beams in excess of 1100°C in the worst cases, no structural collapse took place.
What about these Canadian guys:
A state-of-the-art review of the behavior of steel frame structures in fire is presented. Results from different studies indicate that the behavior
of a complete structure is different from that of a single structural member under fire conditions from the point of view of fire resistance.
Earlier studies also show that analysis and design of steel structures against fire based on their overall behavior could lead to a reduction or the
elimination of applied fire protection to ertain structural members. The effects of continuity, restraint conditions, and load ratio on the fire
resistance of frame tructures are discussed. The beneficial aspects derived from considering overall structural rather than single-member ehaviour in
fire are illustrated through the analysis on two one-bay, one-storey, unprotected steel portal frames, a column, and a beam. Also comparison is made
between the performance of a beam with different end restraints in fire. Results from the analyses indicate that the fire resistance of a member is
increased when it is considered as part of a structure compared with when it is considered as a single member.
Here's more, from the UK's Arup Fire Engineering:
The WTC towers behaved very well following impact and in response to multiple floor fires indicating that it was a
robust system. The draft NIST report appears to rely on dislodged fire protection. Our main concern with this conclusion is that thermal expansion can
swamp all other behaviours and this is not discussed in the NIST report yet. We believe it should be included in a thermo-mechanical analysis to
predict the response of any structure to fire, particularly when determining a probable collapse mechanism.
Collapse mechanism proposed by NIST in April 5 Presentation Report:
The basis of NIST’s collapse theory is also column behavior in fire. However, we believe that a considerable difference in downward displacement
between the core and perimeter columns, much greater than the 300mm proposed, is required for the collapse theory to hold true.
Why upward expansion of the column would act against the mechanical shortening:
Crude initial calculations indicate that the elastic downward deflection at half the modulus (say at approx. 500C) will be roughly 38mm. Assuming
plastic strains, a maximum yielding of approximately 190mm is possible. If the downward displacement is 300mm as assumed, the rotation at the
perimeter connection would be 300mm vertical over an 18000mm span - extremely small.
The floor elongation must be less than 2.5mm to generate tensile pulling forces on the exterior columns as a result of the column shortening in the
core. Thermal expansion of the floor truss would be 65mm at 300°C over a length of 18000mm. Therefore the 2.5mm is swamped by thermal expansion and
the core columns cannot pull the exterior columns in via the floor simply as a result of column shortening. The NIST collapse theory also states that
“floors weakened and sagged from the fires, pulling inward on the perimeter columns. Floor sagging and exposure to high temperatures caused the
perimeter columns to bow inward and buckle—a process that spread across the faces of the buildings. Collapse then ensued”.
This is similar to some of our collapse proposals but no mention of thermal expansion is made, the floor buckling and lack of support to the columns
seems to be entirely due to loss in strength and stiffness in their view which we would consider to be only part of the story.
Why are fire engineering firms outside the US saying different things to the ones employed by the US government to analyze the WTC collapses?
But what about WTC7?! NO jet impact, NO jet fuel, MINOR debris damage, LOTS of smoke but MINOR fires, and BICKETY-BAM! FREE FALL IMPLOSION!!
Seriously, what does it take to make ya go "hmm...." ?
Man... :shk: I give up, I cave in, I implode, I go into global collapse...
[edit on 2005-12-24 by wecomeinpeace]