Would a Pancake Collapse Leave THIS Standing?

Wouldn't a "Pancake Collapse" have amassed so much force and energy by the time it reached the bottom of the building that the force would have completely pulverized the base of the tower?

you still have the same mass falling the same distance with the same energy. Or is CD inherently less energetic than a collapse due to structural failure?

most of the squibs and pops were in the upper stories...It looks like not as many explosives were placed in the lower floors...and the building exploded outwards rather than pancaking down.

did not fall straight down? I thought the towers fell nearly straight down - isn't that what clued everyone that it was obviously CD?

So it was KE and dynamic structural overload that led to the collapse of the lower floors? Finally a glimmer of light!

Of course the falling rubble from 40 floors took down the
other 70 floors.

The question is, how did you get the top 40 floors to turn to
rubble. And how did the birdsnest of a disorganized mass of
rubble take down the fencepost of a core built to hold up 10X
the weight of the building?

how many degrees of flex or inches of lateral movement could those joints sustain before failing? Since it was a chaotic collapse the building was ripped apart.

Your birds nest argument is ridiculous - the mass of the building is still the same and it's KE was certainly enough to smash the lower floors.

Same for you bird post argument - you honestly think that the core could exist as a free standing structure without lateral support from the floor trusses? Look at it's height to width ratio and then imagine it subjected to violent lateral and twisting forces in addition to massive vertical forces. And your 10X figure is dishonest - as we have discussed many time, that figure refers to static loads, not dynamic loads.

is that a significant amount of the mass was still contained within the outer perimeter walls as it collapsed. The outer walls were destroyed as the pressure inside built up. This effect cause the mass internally to retain a "moment of inertia" very similar to the un-collapsed structure.

His bag of sand is a excellent analogy. PG is using it incorrectly. The sand (or building mass collapsing) was not completely free to "spread out" decreasing it energy until the perimeter walls failed.

don't you ever get tired of spouting this stuff?

Here's a chunck of petgoat's "sand": http://www.amny.com/entertainment/news/am-wtcrelics-pg2006,0,6613706.photogallery?index=35

from what floors did that sample originate?

In talking about sandbags I'm talking about the initiation of collapse
at the plane-strike level. Your meteorite may well come from the
fifth floor.

I don't believe I have posted this before, but the picture that you linked to...



... reminded me of something written by Dr. Jones.


I never heard if he obtained a sample, and whether or not it tested positive for thermate if he did.

- Make7

... as being "evidently showing the now-solidified metal" -- just by looking at the picture. A closer picture that's also on the same site shows embedded pieces of paper with printing still legible, which might have altered Jones' "scientific" conclusion.

I believe Jones analyzed a sample from someone who supposedly took it from that WTC memorial made from steel debris. Given Jones' careful attention to detail, it might be a piece of slag from a torch cut.

to hide the evidence?

Large pieces of steel called tridents recovered from the World Trade Center site, and once a structural part of the ground level exterior arches of the twin towers, are preserved in Hangar 17 of Kennedy International Airport. Three are about 1,350 pieces of steel, many weighing over 30 tons.



I wonder if thermate bent that steel column like that? Cuz there certainly wasn't any other forces involved strong enough.

More examples of compressed debris...amazing stuff...

magical magical birds nest mass denebulizer, or was that the magical meatball on fork mass shifter theory?

coreside "clips" were not strong enough to transmit that force.



The internal mass expended its force in peeling away the perimeter columns.

You can not argue that the force was applied laterally to the core rather than
the perimeter because clearly the forces were balanced by symmetrical forces
on the other side, else the collapse would have proceeded asymmetrically.

you think a magic shield prevented the core columns from absorbing any energy of the falling mass, and all energy was transmitted to the outer walls only.

Now that's almost ridiculous enough for NIST or the 9/11 Commission.
I think nothing of the sort.

The cores were 130' X 70'--9100 square feet.

The 47 columns were roughly 1.5' X 3'--47 of them is 211 square feet--
about 2-1/3 percent of the floor area.

Chances of a "upper block" core column scoring a direct hit on a lower
floor core column are thus pretty slim. The kinetic energy would have to be
transmitted by floor membranes in the "upper block" that were not built for
the job, so they'd soon disintegrate. Debris falling down between the columns
would reinforce and bracing them, and would cushion the "upper block" debris
and dilute its effectiveness.

The more I think about this, the more I come to think the core should have
resisted the attack of the debris. The garbage does not cause the collapse of
the garbage can.

rationalized that the planes should have bounced off the WTC.

they were designed to sway in high winds and withstand a hurricane

The mass is the mass. But we have the problem that much of the mass
was outside the core area, the debris in the core area would necessarily
have been disorganized and separated from the floor and perimeter
column debris since the only connection was core truss clips designed
only to bear the weight of ONE FLOOR and perhaps transmit some lateral
forces.

Since the core was overbuilt by a factor of ten, since disorganized mass
tends to expend its force in rattling itself about instead of pounding its
resistance, since the connection between the core and the floors was
not strong, I think the core should at some point have started to resist
the disorganized attack of the debris. Hence my "Bird'snest v. Fencepost"
model.

you honestly think that the core could exist as a free standing structure
without lateral support

No. I think that a five hundred foot section (but not the bottom five hundred
feet) would probably topple, falling on the WFC or One Liberty Plaza or the
Verizon Building.

your 10X figure...refers to static loads, not dynamic loads.

Since the dynamic load on the core comes in the form of a rake trying to
hit another rake, no more than 10% of the dynamic load applies.

what happens when the limbs are stripped from the trunk? Like when heavy snow takes down/breaks the limbs? Does the trunk disintegrate? Does the tree topple without the limbs? Edited to add: I posted this before I knew about Judy Wood and her "tree design" hypothesis, as summarized below. It just makes sense to me.

The World Trade Center Towers as Bio-inspired Structures: Characteristics of their Design and Demise
J. Wood, M. Tedder, D. Smith, G. Lozano, Clemson University

The World Trade Center towers (WTC) were built with a unique design. A photo taken during construction of the WTC towers reveals the robust core columns and floor trusses connected between the core columns and the outer columns. This was certainly a biologically-inspired design, although they didn't use this trendy term back when it was built. The WTC was built like a tree, with rings, so that it could flex in the breeze like a tree. So, why did the WTC buildings collapse? This paper discusses the unique and biologically-inspired design of the towers as well as characteristics of their demise. The most likely cause of the collapse is explained and quantified.

Notice that a bird's nest and a fence post may be built of some of the same material: wood. And the cores and the falling mass also comprised some of the same materials. Yes, there is a difference between a mishmash of twigs and a solid 4 x 4 post. There is also a difference between a steel core of 47 massive columns and a mass of falling debris, massive though it may be, that has already been largely shattered and pulverized.

Your argument about the core's stability speaks to buckling. Buckling does not explain the breaking of the core into pieces. So where are the big pieces of the core?

sort of, maybe..I just read this a while back and I thought of a pringles tube inside a cereal box, sort of. Maybe I was hungry...

The World Trade Center included many structural engineering innovations in skyscraper design and construction. To solve the problem of wind sway or vibration in the construction of the towers, chief engineer Leslie Robertson took a then unusual approach — instead of bracing the buildings corner-to-corner or using internal walls, the towers were essentially hollow steel tubes surrounding a strong central core. The 208 feet (63.4 m) wide facade was, in effect, a prefabricated steel lattice, with columns on 39 inch (100 cm) centers acting as wind bracing to resist all overturning forces; the central core took the majority of the gravity loads of the building.

"Of course the falling rubble from 40 floors took down the
other 70 floors."

That makes no sense and defies engineering.

That implies that you can prove that mathematically. Please do so.

stronger and stronger lower structure.

core rubble pile. Rubble packing between the 47 core columns
to reinforce and brace them.

This, I'm guessing, is why NIST stopped their analysis at the
inception of collapse. They couldn't make the core collapse no
matter what they did. They don't want us to think about why
the core collapsed.

Yup, guessing, AKA petgoat engineering.

do something. That's not engineering, that's empistemology.

As to engineering, nobody can do more than guess in the absence
of the blueprints and the absence of the steel.

But NIST draws pretty pictures so they can pretend that they had invisible
jewish elves in fireproof suits taking temperature measements to by god
PROVE that fires weakened the steel. That's Bush science.

NIST didn't model the collapse because they, and all the qualified experts who have examined it, determined that once the collapse started, there was no way for the building to resist it. The exact and specific failures that happened would be extremely difficult if not impossible to model, and all it would tell you is the same thing that overall calculations tell you: The momentum of the falling debris exceeded the safety factors of the design.

(Edit: Your claim that they "couldn't get the core to collapse" is a dishonest, since they didn't attempt to make any such model. If you want to keep yammering about how they should have done that to satisfy you, then I certainly can't stop you -- but please stop deliberately misrepresenting what they did and didn't do.)

Really? How do you know?

So there.

Prove they did, but "couldn't get the core to collapse" so they covered it. No thanks for more idle speculation.

I'm shocked.

Can you provide a reference to "the overall calculations" that say "the momentum of the falling debris exceeded the safety factors of the design"?

A simple analysis done a few days after 9/11:
http://www-math.mit.edu/~bazant/WTC/WTC-asce.pdf

Dr. Greening's more complete analysis:
http://911myths.com/WTCREPORT.pdf

Gordon Ross, at "Scholars for Truth," attempted a refutation of Greening's analysis, but unfortunately that analysis was flawed by fudging and errors. Ross made a second attempt, but it was also flawed by unjustified assumptions and errors. The basic problems with Ross' analysis, which he has made no apparent attempt to correct are: (1) he analyzed the WTC1 collapse in one dimension, as if the top of the tower fell straight down on the bottom so the bottom absorbed the impact uniformly to its full theoretical capacity (when in fact the chaos of the collapse would have actually displaced columns laterally, so they couldn't have withstood anywhere near their full theoretical capacity); (2) he basically tried to show that the building should have withstood the first floor collapsing by transferring momentum many floors below as the columns compressed, like a spring (whereas the momentum of the floors would have prevented the compression from traveling as far down the building in the time required as he assumed; and (3) he ended his analysis with many floors in motion from that transfer of momentum and the columns between them at their full elastic limit and claimed there was no energy left to continue the collapse (whereas all that momentum was still present with the floors in motion, so the columns would fail while trying to bring those floors to a stop). There are other errors that other people have pointed out, but I think the major basic flaw is that the conditions he assumed are nowhere realistic, and all the realistic adjustments work against the building standing.

(Edit: Those are just the two best known analyses; there have been many, including computer modeling, but I'm sure you can find those for yourself. The point is, nobody has yet come up with an analysis that can withstand true peer review -- not the ludicrous "peer review" by totally unqualified people at ST911 -- that says the buildings should have stood after the collapse began.)

This is about energy, not momentum.

And I am not finding the actual calcs. The main point of the paper seems to be to say that there was enough energy for the buildings to fall at nearly free-fall speed. That would be stated on page 6: "Calculating the dissipation per column line of the framed tube as the plastic bending moment MP of one column . . .the platically disipated energy WP is, optimistically of the order of 0.5 GN m."

Err, how did they get that? They do include a reference. But the calcs are not here, as far as I can see.

And they seem to assume the steel had lost half its strengths from heat. They assume 800 degrees C. Even if there were pockets that were that hot, I know of no evidence that either the fire was located in more than a few small places (and those were not near the core) or that there was so much heat from the fires that it heated the columns to the point where they would lose strength in more than a few places.

> This is about energy, not momentum.

Momentum is kinetic energy. The only way to study the total collapse is to analyze the momentum of the falling mass. The total gravitational energy available in the building was exactly equal to the energy it would take to lift a tower up to its center of mass, i.e., lift nearly a half-million tons about 600 feet. When the impact-level floors collapsed, it was the momentum of the falling top section that did the damage to the next floor below -- momentum -- and momentum is a function of its mass and the velocity it reached after falling about 12 feet. Say you built a table that you wanted to be strong enough to hold a 100-pound sack of sand, but to be safe you designed it to hold 200 pounds or more. What would you expect to happen if you took the 100-pound sack and dropped it on the table from a height of 12 feet? If you can understand that analogy, you are well on your way to understanding why the towers collapsed.

> And they seem to assume the steel had lost half its strengths from heat. They assume 800 degrees C.

No, there isn't any such assumption in the calculations. Weakening of steel undoubtedly played a part in initiating the collapse, but both of those analyses assume that the floors below the falling blocks were at full strength.

. . saying the calcs are right there when in fact they aren't.

And it doesn't help that you advertise your inability to grasp the difference between momentum and energy.

"Kinetic energy is the energy by virtue of the motion of an object."

"Momentum is the product of the mass and velocity of an object."

So being picky, yes there is a difference, but the two are directly related because both are dependent on the same things -- mass and velocity -- and only those things.

Sorry for the imprecision, but you said, "This is about energy, not momentum." The kinetic energy of the falling mass when one level of columns fails is calculated in both those papers, and it's shown to be sufficient to fail the next level. So I assumed you were referring to Greening's use of momentum transfer for slightly different purposes: In that paper, the reason that the question of whether or not the collapse will continue involves transfer of momentum is because, since kinetic energy is not conserved in a inelastic collision (because some is used to permanently deform and break stuff and some is converted to other forms of "unrecoverable" energy such as heat and sound), but since momentum is conserved is both elastic and inelastic collisions, you can use the principle of conservation of momentum to determine the velocities of the two masses after the collision even though it's inelastic. That velocity is the starting velocity as gravity continues to accelerate the masses, which determines the velocity at which the next floor is impacted, which determines the kinetic energy available in that next collision.

The other place that Greening uses conservation of momentum is in the calculation of the expected collapse time (a different issue), and it's for the same basic reason: to calculate the velocities after the collisions.

Better?

> saying the calcs are right there when in fact they aren't.

You mean because he didn't "show his work" for the "plastically dissipated energy?" Well, he did explain pretty precisely how he derived that number and provided a reference (his own co-authored book, since he's an expert on the subject), so you or anyone else can do your own calculation, which is not significantly different than checking his calculation if he had included it in the paper. What are you suggesting: that he used the wrong method, that he made a math error, or that he just pulled the number out of his butt? Or is nit-picking the best you could come up with?

Right, that's what I always say when my boss asks me what time I got out of bed
in the morning. "I can't tell you the exact time."

No, the exact features of the collapse are not known, because some snake in the grass
destroyed the steel that might have told the tale.

but please stop deliberately misrepresenting what they did and didn't do.)

If modeling the collapse is not necessary because the experts say they know inception
equals total progressive collapse, then why bother to model anything at all?

Why don't we just let the experts tell us "believe us, we know what we're talking about,
and it's too complicated for us to explain, but we know."

I'm sure you and your professionals of great integrity would be happy with that.

I know, you prefer the special Cliff Notes version at the "truth" sites.

> If modeling the collapse is not necessary because the experts say they know inception
equals total progressive collapse, then why bother to model anything at all?

Actually you don't even need to read the report to know that, since they put the reasons for the study right on their home page:



You seem to be laboring under the misconception that the purpose of the FEMA and NIST investigations was (or should have been) convincing conspiracy crackpots that it wasn't an "inside job" pulled off with explosives all over the building or thermite or Death Star beam weapons, so in your opinion they failed in what you perceive their mission should have been. But why should they spend time trying to accomplish that impossible mission? If they had modeled the collapse after the initiation, why would anyone expect you and your CT buddies to accept that model any more than you've accepted everything they did do?

Anyway, I'll answer your question in general: There were many good reasons for wanting to understand what initiated the collapse -- read that section above again -- but there were no compelling reasons to model the collapse after it got started, because people who understand those things understand what happened after that. And CTers never will, because they refuse to.

I am laboring under no misconception.

I understand fully that the charge of the NIST report was NOT to tell
us what happened on 9/11, but rather to improve fire safety in buildings.

Thus the report was skewed from the start toward the assumption that
fire brought the towers down, and those who cite it as if it explained
what happened on 9/11 are laboring under a misconception.

The function of the FEMA and NIST reports should have been to provide the
public with an honest, thorough, and competent account of what happened
to those public buildings on 9/11. Unfortunately they failed--FEMA
because of inadequate funding and obstruction, and NIST because of its
own dishonesty.

people who understand those things understand what happened

Right. Trust the Bush experts. Though they tell us that modeling the
collapse is too complicated for them, they know enough to assure us there's
no need to model the collapse.

> The function of the FEMA and NIST reports should have been to provide the
public with an honest, thorough, and competent account of what happened
to those public buildings on 9/11.

Correct. And most people believe that that's exactly what they did, to the best of their ability. OF COURSE YOU don't think so, because you made up your mind that you "just knew" before they even got started that it was an "inside job," which you rationalized by convincing yourself, before they started, that flying airplanes at full speed into buildings shouldn't cause that to happen. The one and only thing you wanted out of FEMA and NIST is for them to find out what kind of explosives were planted where, because the one and only result you would accept was that your were right all along. Now, as demonstrated over and over on this board, there is absolutely no way you will allow anyone to explain to you why that happened.

> Unfortunately they failed--FEMA because of inadequate funding and obstruction, and NIST because of its own dishonesty.

"Unfortunately" they failed to tell you that you were right all along. "Unfortunately" there wasn't any evidence that you were right all along, so you need to convince yourself that either they must have missed it or they must have covered it up.

> Right. Trust the Bush experts.

How delusional do you have to be to think that the the reason you can't find a qualified expert, anywhere in the world, to tell you that you were right all along is because they're all "Bush experts?" As delusional as it takes, apparently.

Your post is total baloney.

you "just knew" before they even got started that it was an "inside job,"

You're projecting your tendency to "just know" things, claiming you "just know"
what I "just knew."

At the time NIST started its investigation in August of 2002, I found Dr. Eagar's
zipper theory plausible. I found Bush's exploitation of 9/11 for furtherance of a
neofascistic agenda disgusting, but I believed not even he could be so evil as to
let an attack happen on purpose to serve that agenda. Like everybody else I had
a life and my own concerns, and no need for a bunch of scary complications.

I have very reluctantly come to consider the CD theories plausible, and have never
forgotten that without expensive investigations they can remain nothing more than
theories. One of the greatest arguments for the CD theory is the destruction and
suppression of evidence, and the obstruction and poor quality of the investigations.

you rationalized by convincing yourself, before they started, that flying airplanes
at full speed into buildings shouldn't cause that to happen.

Au contraire, I assumed the intuitively obvious: That the fireballs represented only
the leakage from massive explosions that had devastated the tower cores, that blazing
infernos had weakened the steel, and the towers thus failed.

It was only later that I learned that the fires were short-lived, that a fireball does not
exert explosive pressure, that Orio Palmer radioed from the impact zone about isolated
fires, that Brian Clark walked down from above the impact zone and saw few flames, that
Dr. Eagar said the impact force of the planes was negligible, that the period of
oscillation of the towers remained the same after impact so the structural damage from the
planes was negligible, that the steel was destroyed before proper samples could be taken,
and that the ASCE investigators were not given site access and had trouble getting the
blueprints.

there is absolutely no way you will allow anyone to explain to you why that happened.

No one who defends the NIST report has any credibility with me. The report's failure to
express regret about the destruction of the steel, its fudging of the computer models, its
assumption of what it purports to prove, its failure to model the collapse, its obfuscatory
detail, the spinning of its own data, the failure to provide the visualizations, the fudging
of test protocols, and the presentation of model data as if it were empirical data are
dishonest and offensive.

The NIST report will stand with the 9/11 Commission Report, the Bush v. Gore decision,
the Iraq war, and touchscreen voting machines as an historical monument to the cultural
decline that some of us are trying to reverse. No thanks to you!

"Unfortunately" there wasn't any evidence that you were right all along

The only things I claim to be right about are:

1. the zipper theory was absurd on its face
2. NIST's report is shoddy, dishonest Bush science
3. the explosive hypothesis has not been adequately examined
4. the destruction of evidence gives the appearance of a coverup
5. ASCE and NIST's failure to comment on the destruction of evidence shows basic dishonesty
6. We need a new investigation
7. We need release of the suppressed evidence: the 7000 photos, the 7000 videos, and the
WTC blueprints

How delusional do you have to be

See the comments about professionalism elsewhere.

For instance, here and here:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=94447&mesg_id=130627

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=94447&mesg_id=131512


In my experience, professionals do not risk their hard-won credibility by pitting their inadequate
resources against controversial windmills.

The risk of tainting by association their partners, their clients, their firms, their mentors,
and their friends is not professional. It's poor judgement, it's bad for business, there's
no profit in it, and it's just plain dumb.

Sorry if I (continue) to doubt your claims of coming to your opinions only after rational analysis of the evidence, but (1) the actual evidence and reasoning are simply not persuasive except to people who need very little persuasion, or to those who blindly accept that evidence and reasoning without looking for alternative explanations for what happened; and (2) your obstinate refusal to accept that any piece of that evidence or reasoning is flawed indicates quite clearly that evidence and reasoning are not of foremost importance to you.

or reasoning is flawed?

:eyes: Oh, how about every time I've ever seen you confronted with any evidence or had you logic refuted, by anyone? Want to tell me again about how those heat waves were making the columns simply appear to be buckled? Want to tell me again how the building was designed to hold up 10x it's weight? (Oh, that's right; when confronted on that one, you upped it to 20x.) And how Kevin Ryan "knows junk science" because he told you about how buildings are really over-designed like that. How about the one about the "absurd zipper theory" -- one of my personal favs. Or, your supposition that the tops of the towers mysteriously turned to sand (or a birds nest, or a meatball), so they should have poured harmlessly on the structure below? Except of course that they were also exactly like smacking a crack between your palms, so there's no way all that dust should have been expelled out the side, which also proves that the "squibs" must have been explosives. Or how NIST tried to model the collapse but couldn't get the core to fail so they covered it up? I really love the one about putting up buildings with the explosives already to go because that's good "contingency planning." And, yes, the one about how professionals are duty-bound not to make a fuss about murdering 3000 people.

That's just off the top of my head, covering just the past week or so. Nope, no refusal of evidence or faulty reasoning there. Just good ol' following the facts with common sense reasoning wherever that leads. :eyes:

Your invocation of the 2.0X safety factor for column design
neglects to add the factor of redundant numbers of columns.
Multiplying 2.0 X 2.5 yields a safety factor of 5. Doubling
that for hurricane strength yields a safety factor of ten.

I have many times explained to you that the zipper theory is absurd because
it supposes that the perimeter clips were so flimsy they unzipped, but the
core clips were so strong that the floors took down the core.

Your only response is to invoke the authority of the legions of engineers
who (wrongly) supported it.


That's just off the top of my head

It certainly is. How it relates to your claim that I refuse to accept
that evidence or reasoning is flawed I can't fathom. Feel better now?

> It certainly is. How it relates to your claim that I refuse to accept
that evidence or reasoning is flawed I can't fathom.

I wonder why that is. :eyes:

> Your invocation of the 2.0X safety factor for column design neglects to add the factor of redundant numbers of columns. Multiplying 2.0 X 2.5 yields a safety factor of 5. Doubling that for hurricane strength yields a safety factor of ten.

I'm telling you once again that that is utter horseshit. Buildings are not designed with 2-1/2 times more columns than they need, and we've already been through how the core columns had nothing to do with resisting hurricanes. And I'm telling you that because it relates directly to your denial in the quote above.

> I have many times explained to you that the zipper theory is absurd because it supposes that the perimeter clips were so flimsy they unzipped, but the core clips were so strong that the floors took down the core.

And I've proved to you that you are misrepresenting the theory by directing you to the source, and I've also explained the absurdity of assuming an absurdity without studying those perimeter connections, just as NIST did. But, no, that's not good enough; I have to say it again and again and again, despite your denial in the quote above.

I'm not misrepresenting the zipper theory. The zipper theory
forgot to explain what brought the core down. That's my point.
NIST's theory forgot the same thing.

And the columns DON'T appear to be buckled. You're presenting
pictures of columns that appear to be bowed, but may only appear
that way because they're photographed through a sheet of hot air
that bends the light. And you claim the pictures show buckled
columns. Where are the buckled columns?

we got your back bud. trust us. trust us.

Message removed by moderator. Click here to review the message board rules.

I think you're over-generalizing from an early-morning typo, or do you
have something specific in mind?

pretty clear, isn't it?

My "simple common sense" says there's no way to prevent it if the momentum exceeds the ability of the structure to absorb impact, and my "simple common sense" tells me there's no good way to guess whether or not that's the case without doing some quantitative analysis, which many engineers have already done. But you said it "defies engineering," which seems to be at odds with those engineers. Are you retracting that, or can you explain to me where they went wrong?

They just assumed that since it happened, therefore it was
reasonable to take it as a given.

NIST did not continue their models into the collapse because
they couldn't get the core to collapse.

All this in IMHO.

Since the "floors" were built only to hold themselves
up, to me the proposition that five collapsing floors
could have brought down the sixth seems reasonable.

What is not reasonable is that the core should have collapsed.

Stripped of the supplemental lateral support of the floors,
the core would have toppled eventually, maybe in 500' chunks.

Here's a picture from 09-13-01



You can see from the walls that were left standing how high the debris pile is. Not very deep is it?

The tall arches were once part of the lobby. The debris pile doesn't even reach half way up those arches. Where did the rest of the building go? Most of the building fell into the plaza and the perimeter around the building and a large amount simply blew away.

the debris first filled a massive subterranean hole.

of the buildings mass did not fall straight down. Look at the material in the actual footprint of the buildings. There is not that much material in there. You can measure the height of the debris piles based on the level it comes up to within the perimeter walls that remained standing.



The debris pile certainly doesn't go much higher then those cross beams in the windows. So 2- 3 stories high at the most? WTC7 left a taller debris pile.

It was mostly steel that went straight down. The aluminum cladding is found scattered around and further from the building. Everything else was turned to dust and a lot of that dust just blew away.

No this was not a controlled implosion. It was a controlled explosion.

Back to the drawing board.

And how did everything inside turn to dust? Explosives? When you consider that the WTC had an open floor plan where did they put the explosives? Were there massive bombs in the core (in which case where is the pressure front that they would produce?) or are you saying that they covered each floor or ceiling with many smaller charges? Just how was it done?

but a lot of it did not cave in. Remember the pictures or the trains and the shops that were in the lower levels? The Plaza did not cave in and neither did the streets around the perimeter of the site.

Good question. But can you seriously maintain that it didn't?

that shows what was happening on the lower floors. The building coming down covered up what was going on behind it very nicely.

http://video.google.com/videoplay?docid=-3737206187992152016&q=pancake+collapse&hl=en

911 Twin Towers Improbable Collapse You Were Robbed!

IMHO it's better than Mysteries, although I haven't seen all of that.

If you're looking for pictures of the collapse, you should probably consider
our old friend southcorestands:


It shows that the lower portion of the South Tower's core is still intact
about 10 seconds into the collapse, although the upper section has fallen,
as has the rest of the lower half of the tower. There's a video taken by a
firm of architects from the other side that shows basically the same thing,
although it's harder to make out.

that remained for a short time after the collapse probably wasn't the core.

I think it was more likely a plume from the fuel that was used to destroy the building.


Here's an example of what I am talking about -



An enormous cloud of fuel exhaust is left in the air as Ariane 5 heads into orbit

to cause a collapse would do that

that's not "random" and there was no sign that the fires were throughout the building.

How can it be both "selectively targeted" and "symmetric"?

Many of the tress near the epicenter remained standing because the force from the blast was directed downward.

a asteroid caused the towers to collapse:shrug:

But, no I was not making that speculation. Although now that you mention it an asteroid impact would explain the collapse and seismic observations. It's probably less idiotic than the no-plane "theory."

I was merely pointing out the the tower pancaking down did not require the complete obliteration of every inch of columns. As in the Tunguska event energy directed downward or away from the standing objects would not necessarily knock them over.

And I must admit, some of the theory's out there trouble me because of their lack of scientific and mathematical backing.
It seems, to me, that some people propose scenario's based on fantasy or on supposed developmental weaponry that has no proven scientific background.
This bothers me greatly, it has a tendency to lead people off on tangents that get us no closer to the truth.

About 10 seconds into the collapse nothing was left of the tower except a lower section of the core.

By the time the dust cleared, that lower section was gone.

The only force acting on it, as far as I can see, was its own weight. No sagging floor trusses remain to pull it down.

What did pull it down?

I don't think so - it required lateral support from the floor trusses. The WTC was an integrated system designed to withstand and distribute massive forces - it is not reasonable to expect that one portion can remain intact when all the others are destroyed.

"Poof"?

If the core was simply unable to stand on its own, it would have toppled. That piece of core looks to be about 400 feet tall. You would have noticed it in the rubble.

I agree with Vincent_vega on something.:pals:

:toast: :party: :beer:

it was subjected to many violent forces - it was pushed, pulled and twisted. A joint failed and once it was no longer vertical the rest failed. Are you arguing the rest of the tower fell without damaging or moving the core despite the fact that they were all connected?

baring any lateral forces, i.e. wind, it should be able to remain freestanding to a point. You would reach a height where the vertical load combined with even a slight lateral load would make it unstable.

to a structure that violently collapsed, it was not subjected to any lateral forces? OK:eyes:

You asked if the core was designed to be a free standing structure. I just answered your question without any consideration of the collapse, or it's effect. So let's try this again, Was the core designed to be a free standing structure? No, it was not. Could it have been, yes, to a point.

Please dude, I have more respect for you than that.

The would not have fallen down liken some old man's trousers, Once the outer perimeter and truss system became compromised, and the structure was in motion, the stress on the core would have been enormous.

There was nothing to pull on it, because anything that would have exerted force on it was gone. After what it had been through, was it stable? I don't know. But in a few more seconds it was gone. What could possibly take it down that fast?

as it was damaged and battered by the collapse of a massive structure it was attached to. Seems pretty straight forward to me. As for the speed, the core weighed a lot - gravity would have pulled it down pretty quickly.

As I said, it was probably 300 or 400 feet long? If it teetered and fell, there should have been pieces that long left.

it was made up of many smaller beams - the joints failed in the collapse. It is not a tree. It was a massive steel structure with tremendous mass that would have generated tremendous forces as it collapsed.

There you see it standing, with nothing attached to it and most of the collapse debris dissipated.

So what brought this down?

Buckling causes columns to fail before they reach their full material strength; they bend to the side because the slightest asymmetry in either the column or the applied force causes a bending moment, which immediately increases when the column starts to bend even a little. The buckling resistance of a column decreases with the square of the unbraced length: twice the unbraced length is 1/4 the buckling resistance, etc. (Buckling resistance is the main purpose of the cross-bracing in the crane towers.) The cores weren't designed to stand alone: The floors braced the columns against buckling.

But you knew that.

You should have done at least a little bit of research about what buckling looks like before you posted your "conclusive evidence of premeditated murder," Fosdick. And you could also do your own research to verify that FEMA investigators -- people who do know what it looks like -- reported that about half the core columns were buckled. But once again, you posted something foolish, and now the board has to read it over and over again, simply because you can't admit that you were wrong.

But you knew that. :banghead:

It's been blown apart. Where are the welded plates that were originally on the front, for example? And no, "gravity" didn't tear it to pieces.

The missing side plate was stitch-welded on, which was weaker than the bending strain that would have been required for that plate to bend with the buckle. My guess would be that it wasn't completely ripped off by the buckling, though -- it wouldn't need to, to relieve the buckling strain -- I'd guess that happened as it was ground up in the falling debris and in hitting the ground.

Buckling deforms a column, explosives blow it apart, and no, they are not the same as bending.

:rofl:

Of course, it would be nice if you knew what you were talking about, but I've gotten used to that by now. The ROFL smiley is especially ironic. Do you expect those of us who actually know this stuff to accept your arguments, especially when you've repeatedly exposed how little you know?

I was hoping you would. (n/t)

I see that engineering is not the only area where your education and experience have fallen short.

of fire damage on that piece. The buckling appears to be caused by the collapse. There's a fair number of pieces of steel that are bent this way.

Where's the steel from the impact and/or fire zone that caused the failure? Where's the steel from the towers that looks like this?




Those pieces should have been apparent when they were uncovered. Besides, even if they weren't obvious, every piece of steel was numbered. What's the ID on the piece in your picture? Without knowing where in the building the piece was, it's hard to tell what happened to it.

Also, why didn't NIST or FEMA recover and document all of the pieces from the impact/fire zone? They couldn't afford it?

They could have rebuilt those zones like they do an airplane, or at least lay the pieces out side by side, and they would have known exactly what went wrong with the building? Why didn't they do stuff like this?

but so far it's the only core column (if that's what it is) that I've seen in that condition.

Have you seen others?

It wasn't fire damage to the core columns that caused the collapse. It was the fire damage to the floor joists and the resultant sagging, followed by buckling of the perimeter columns when the joists pulled them inward enough that they couldn't withstand their loads.

There must be few of them laying around here somewhere?



BTW: If the Towers failed because of damage to the perimeter columns, why didn't the buildings fall in the direction of the impact zones?

I would expect that since the north side of WTC1 was the most heavily damaged, with a big hole and lot's of columns missing that the building would fall toward the north.

recovered from the debris pile?

Shouldn't have been hard to find them.

http://video.google.com/videoplay?docid=-5405555553528290546&q=wtc+collapse+church

We know from numerous photos and videos that the perimeter columns were buckling -- there are many more photos in the NIST report -- but this video is by far the best evidence I've seen that that's what initiated the collapse: The columns clearly cave inward.

I think CTers ought to forget about explosives and thermite and Death Star beams and try to figure out how the perps rigged all those columns with cables and pulled them in with a giant winches hidden all over the building. That's no less ridiculous than the other theories, but that one would at least match the evidence, which puts it head and shoulders above the others.

http://www.nyctv.com/Censor_911_Video.htm

The "Pop" and Flashes starting at about 7:53 in this video...

After 20 minutes, it hadn't even downloaded the first minute of the video, so I gave up. Don't ask me to waste hours downloading just to see a couple seconds of something you think is "suspicious" -- not when to CTers, everything is suspicious. Anyway, there surely would be videos taken closer to the scene -- there wouldn't be any way to tell from that video which sounds were coming from the tower, from down the street, or from the same room. If the "pops" are happening at the same time as the "flashes", you can be sure they aren't related since it would take at least several seconds for sound to travel that far.

But I also reject the pancake theory, which it appears you still support, even after all those experts at NIST tossed it out.

So you think the NIST experts are wrong eh?

I guess we agree on that.

Quit playing games.

What William says he believes is the older NIST story, not their current one.

Check it out. I'm not playing.

NIST says that heat damaged the cores, causing some of that load to be redistributed to the perimeter columns. If the effects had stopped there, the building would have probably remained standing, so that's NOT what INITIATED the collapse, according to the final NIST report. What INITIATED the collapse was the floors pulling the perimeter columns in until they buckled. Perhaps that seems to be a subtle nuance to you, but that doesn't make your assertion true.

Your post is too unintelligible to think of any response except to note that I don't see any evidence whatsoever that you know what the "pancake theory" really means, what the NIST final report says, or what I think. Not much left, except I'd bet we don't agree on much of anything.

went out with the pancake theory?

The NIST folks claim that the core columns Softened and buckled first.


WTC 1

* Aircraft impact damaged the perimeter columns, mainly on the north face, resulting in redistribution of column loads, mostly to the adjacent perimeter columns and to a lesser extent, the core columns.

* After breaching the building’s perimeter, the aircraft continued to penetrate into the building, damaging floor framing, core columns and fireproofing. Loads on the damaged columns were redistributed to other intact core and perimeter columns mostly via the floor systems and to a lesser extent, via the hat truss (the steel structure that supported the antenna atop the towers and was connected to the core and perimeter columns).

* The subsequent fires, influenced by the impact-damaged condition of the fireproofing:

* Softened and buckled the core columns and caused them to shorten, resulting in a downward displacement of the core relative to the perimeter. This led to the floors (1) pulling the perimeter columns inward, and (2) transferring vertical loads to the perimeter columns; and

* Softened the perimeter columns on the south face and also caused perimeter column loads to increase significantly due to restrained thermal expansion.

* Due to the combined effects of heating on the core and perimeter columns, the south perimeter wall bowed inward and highly stressed sections buckled.

http://www.nist.gov/public_affairs/releases/wtc_latest_findings_1004.htm

 

If you are going to present the position of NIST, please use the final report when the page clearly states that the findings currently presented may be revised before the final release.

If what you have presented is their final determination, it will also be included in the final report.

Thank you.

- Make7

If it buckled the pieces should remain whole. Where were the 400-foot pieces just after the collapse? They should have been evident.

And what reason is there to assume that the pieces were not braced? Even with the floors gone, there was cross bracing.

The core columns were in 30' sections, welded together. The same forces that cause buckling would cause the welded joints to break.

It appears the core columns had some cross bracing, but they were not fully cross braced like a truss tower, so that bracing would restrain only some of them, and even those in only one direction. They depended on the floors, both inside and outside the core, for full lateral restraint to prevent buckling. Those floors, inside and outside the core, were destroyed by the collapse. I'm not sure where this idea came from that only the outside floor slabs were destroyed, but it's not realistic. The floors inside the core were also being battered by the falling debris from above.

"The same forces that cause buckling would cause the joints to break."

Here we have a bunch of columns strong enough to hold 70 floors on top of them, and now they have nothing on top of them. So what forces would cause either buckling or breakage?

The building above fell on the building below, and even if some columns remained standing through that but then buckled lower down, those sections fell and hit the ground. So, we're mainly talking about impacts rather than static loads in either case.

The part you're missing, I think, is that the columns might have been "strong enough to hold 70 floors on top of them" but only if they were held vertical by the floors. Otherwise, ultimate strength wouldn't necessarily matter if they weren't stable enough to remain standing.

This a severely compressed column from WTC5.

Also there are signs of fire damage on the column and in the debris around it.

... which is buckling over a relatively small area -- not the entire column -- and in that particular case it's clearly due to weakening by heat, whereas unheated columns can also buckle under overloading (although a properly designed column shouldn't have local buckling like that). Don't start sounding like dailykoff who thinks there's only one kind of buckling and he doesn't see any in the tower columns. That's not a productive way to understand what happened, if you're really interested in such things.

before you start spouting nonsense about buckling.

p.s. I made a study guide for you here:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=131379

No charge. :)

... just not in structural engineering. (However, I did grade your structural engineering homework, and unfortunately you once again received an F.)
:banghead:

Hilarious.

never mind

http://gordonssite.tripod.com/id2.html

This is an excellent analysis of how the buildings collapsed with staged demolition.

Thank you.

From a glance, I think he and I are on the same wavelength has to what happened to these buildings.

I also think the mechanical and fuel systems in the buildings were used to bring the buildings down. There was no need to wrap columns with explosives or any of that sort of thing.

The mechanical floors were key to taking the buildings out.

they all would have fallen and ignited due to the tremendous pressure, creating a fireball that would have melted the structural steel of the base of the building.

the conventional explanation of the destruction of these buildings is transparent bullshit.

What would structural engineers know with their fancy degrees and relevant experience?

theory for three years.

When NIST overthrew that, not one structural engineer
would defend it.

Besides, what do structural engineers know about office fires?
About all they were good for here was reverse engineering an
only half plausible-sounding post hoc ergo propter hoc
rationalization.

And let's not forget that Mr. Zipper himself (Eagar) is not a structural engineer.

Gotta love the irony.

This forum is topsy-turvy land where web-jockeys "go with their gut" in misanalysing and mislabelling of video and pictures, rejecting the conclusions of forensic investigators and structural engineers. The conclusions of these trained persons over-complicate the 9/11 Truth movement's attempts to formulate a simplistic worldview.

Engineers have no more immunity to fallacious reasoning than anyone else.

Although structural engineers have not presented a logical fallacy to my knowledge.

The failure to investigate the explosive hypothesis can only derive
from the assumption that since there were fires, they must have
caused the collapses.

that two large airline jets crashed into the Towers and the Pentagon. No doubt it was a logical fallacy on their part not to explore the holographic no-planes theory. :eyes:

IMHO a truly thorough report would have examined the evidence for the holographic
no-planes theory. With respect to the towers it was a can of worms, because if it
were given any credibility then the fires and collapse would have had to be examined
in a more open-minded and costly way. Apparent TV footage of the second strike gave
an excuse not to "waste time" on such ideas.

Lack of Pentagon TV footage makes that analysis more problematical. Are you aware
that the civil engineers' report shows that the damage to the Pentagon wall was
inconsistent with a 757?

The marks on the wall are not consistent with a 757's wingspan, so the engineers' report
has to suppose that the right wingtip was clipped off by impact with the generator, and
the left wingtip was clipped off by impact with the ground. These assumptions are made
despite the fact that neither wingtip has been recovered, and no pictures of ground damage
consistent with wingtip impact have been produced.

Engineers do not have unlimited time or unlimited budgets. They have to get the job done.
They are pragmatic people. Such assumptions are not "lies," they are "problem solving."

a truly thorough report would have examined the evidence for the holographic
no-planes theory.

IMHO a really, really , truly , truly, truly thorough report would have included fairies, Tesla weapons, boogie men, telekinesis, and Arrakis worms imported from Dune via the Guild.

What you are expecting is ridiculous. No engineer or qualified professional is going to investigate hair brained dark weaved fantasies.

There was a time when science was similarly lumped with satan-worship.

I have not myself taken the time to investigate the hologram theories,
the pod theories, or the exotic weapon theories, so you can see where
my prejudices lie.

I'm assuming that there is some explanation for the TV-footage anomalies
that are claimed, that giant holograms are impractical and unnecessary
(because remote-control flying a plane into a radio beacon in the tower
is not that difficult), and that the pod people's claim that the pod
is actually clearly visible in that major newsmagazine photo is not valid.

Exotic weapons I have been slow to examine because of the problem of the
power supply, but in this regard the proximity of WTC7's electrical
substation is certainly interesting. The notion that the basement bomb
reported by William Rodriguez was set off to remove a floor to allow
an exotic weapon hidden in the basement to gain access to the elevator
shafts is also interesting.

Failure to consider all the reasonable possibilities is not scientific.
I fail to see the relevance of fairies or telekineses. Such phenomina have
not to my knowledge impinged on public events before.

Engineers on the whole tend to be rather stodgy thinkers, so I think they
should challenge their sense of what's hair brained. Why should they not
consider that secret military technologies might be involved?

Reasonable possibilities should be investigated. No planes is not a reasonable possibility. There is no evidence for it, and ALL evidence points to real planes hitting real towers.

evidence.

The no planes at the towers evidence is that the Naudet airplane is a flying pig and
there are allegedly anomalies and inconsistencies in the videos of the south tower
strike.

I have not taken the time to investigate this evidence, but it is evidence.

I thought that tour was long over. Love the album, though.

hired by Big Tobacco were unqualified? Were they not professionals?

It seems you attribute moral integrity to those humans who happen to enter various professional fields.

Do you have any evidence to support your theory that they are any more moral than say, police officers, janitors or climate researchers hired by big oil?

My bet is, if the money was right, one could hire qualified professional researchers to study anything.

Or do you believe they are somehow immune to lucrative employment opportunities?

In the case of tobacco industry "experts" what they have to say goes against the vast majority of scientific opinion. In the same way as "creation scientists" do. It is the 9/11 Truth movement that has come to various conclusions that go against the vast majority of the scientific community.

What you're talking about is getting into Cartesian Demon territory. There remains on unverifiable possibility that a random professional can be influenced under political or financial pressure, but that goes for everybody. However unless one can produce evidence that say that large numbers of structural engineers and forensic experts have been influenced to falsify evidence then this is just meaningless. To imply charges of corruption without evidence is malicious.

provide a list of the qualified and professional people you seem to speak for.

Also, how many of that large number endored the pancake theory before they endorsed the damaged core theory?

Thanks for being specific.

since most people consider MIHOP theories to be from the darkside of the moon, so there is little need to come out and reject MIHOP.

"After, therefore because of" is a logical fallacy if that's the only reason for an inference, a faulty assumption of causality. That's not at all the reasoning. There were fires, fires are certainly known to weaken and warp steel, the perimeter columns were observed to buckle inward which initiated the collapse, there was no evidence of any other cause for that buckling effect (and explosives certainly couldn't cause inward buckling!), therefore the fires most probably caused the collapse. That's a perfectly logical conclusion -- no "post hoc ergo propter hoc" about it. I trust you won't make that false claim again?

column bending are actually artifacts of heat refraction of light.

No buckled columns have been photographed or produced.

The assumption that heat caused buckled columns which caused the collapse
is only an hypothesis.

For the umpteenth time:
http://video.google.com/videoplay?docid=-5405555553528290546&q=trinity+wtc+collapse&hl=en

Those columns buckle inward in that video, so which is it: either your eyesight is really bad or your ability to deny evidence is unbelievably impenetrable. Your "theory" that heat waves caused that and the buckling clearly seen in many other videos and photos is idiotic, and yes I think I understand the phenomenon well enough to say that, so please spare me yet another dead-horse rendition of your misconceptions about it.

Your ability to deny that you're misrepresenting Eagar's theory based on what you think the theory ought to have been is mind-boggling. You keep asserting your misrepresentions and misunderstandings about the tower cores no matter how many times I give you evidence and rational argument that you are simply wrong, and although you apparently can't refute those facts and arguments, you just deny them and than make the same assertions again at the next opportunity.

I don't even care to waste the time it would take to go through more examples of your denials and disingenuous arguments -- there are too many of them. Your ability to protect your delusions is phenomenal, but you are becoming tiresome and annoying, and really not worth the time it takes to respond to the exact same crap over and over and over.

claiming "the answers are all in here, trust me!"

In that video the collapse happens so fast I don't see understand
how you can claim it shows anything. All I see is dust.

My representation of Dr. Eagar's theory is that it doesn't explain
how the core fell down. That's why I consider it absurd.

what they know would depend on their educations and how much work they put into studying the issue

what they say would depend on who signs their paychecks

of structural engineers being paid to lie, I'd love to see it. Otherwise you're just slandering professionals because it fits into your MIHOP theory. A theory that Congressional Democrats, the intellectual left and scientists with relevant expertise won't touch with a bargepole.

It's about being paid to answer questions such as
"How did fires bring down the WTC?" and not to ask
questions that are time-consuming and unproductive.

It's about serving the interests of the nation in
improving fire safety so that insurers and bankers
and office workers can have confidence in American
construction techniques.

It's also about nobody being at fault. Not the
designers, not the constructors, not the commanders
who ordered the FDNY men into the building with no
idea that it might collapse.

Nobody was at fault except the lunatics flying the
planes.

(edited to add no-fault discussion)

Besides discretion and judgement, professionalism involves
knowing what your bosses and the clients want without the
necessity of being told.

Those memos can cause so much trouble in case of an investigation.

You're just underhandedly accusing those professionals of not telling the truth (without evidence, under the favourite Troofer 'guise of "I'm just asking questions".) I am not impressed.

That's the way the professional world is.

You do what you're paid to do, to answer the questions you're asked.
You don't add unnecessary and costly complications.

Besides, they're NOT telling the truth. They failed to mention the
material fact that their investigation was done without the benefit
of an examination of the steel that would have told what happened.

They assume what they purport to prove. How truthful is that?

So you agree with me that the majority of structural engineers and forensic scientists have sound qualifications, training and have been truthful to the various bodies involved investigating 9/11, and that the evidence they have presented is factual?

Any collaborative intellectual effort by a couple of hundred honest people
can be subverted by a couple of key decision-makers who through incompetence
or manipulation by special interests emphasize certain areas of investigation
and ignore others.

Most of the grunts on the effort were involved in compartmentalized technical
investigations and probably performed these competently and honestly.

Which is why the argument put forth by some here that criticizing the report
somehow slanders hundreds of engineers is silly. Just as silly is the argument
that every engineer involved endorses the "big picture" results. Few of them
had input into the big picture results.

> That's the way the professional world is.

We're not talking about the boss sleeping with his secretary. We're talking about what you claim is deliberately covering up the murder of 3000 people! That's not "professional discretion" -- that's complicity. Apparently, you don't realize how asinine your argument is.

Edit: And you damn betcha that's slander. I'd sue your ass in a heartbeat.

What an irresponsible thing to say! We're talking about fire safety!

We're talking about avoiding wasting resources on work outside the scope of the investigation.
We're talking about not adding fuel to loony conspiracy theories.
We're talking about restoring confidence in American science, American government, Americam
engineers, and American buildings.
We're talking about painstaking work to reconstruct what happened without benefit of steel samples
or site visits.
We're talking about doing good solid work for the nice guy that signs the checks.

Why do you want to mess up our beautiful minds with such ugly thoughts?

Message removed by moderator. Click here to review the message board rules.

And that pretty much goes for the rest of the FEMA/NOVA/NIST lunacy too.

The collapse obviously did leave some pieces of facade standing. Unless you have evidence to the contrary, it's kind of a moot question, isn't it?