Why existing 9/11 photography proves beyond doubt that the Trade Center was DEMOLISHED:

[dailykoff]

Or more specifically, why existing video and still photos prove beyond doubt that the towers did not collapse as a result load failure caused by damage from airplanes or fires:

1. When a building collapses as a result of load failure, its combined dead and live loads (typically gravity, earthquake, and/or wind loads) overcome the load-bearing capacity of its structural members. When this happens, each failed structural member shows a distinct pattern of failure, such as the buckled column seen below:



2. In the official WTC explanation promoted by the media and federal agencies such as the NIST, we are asked to believe that plane crashes and fuel fires weakened local core and perimeter columns (visible in the large construction photo linked below) to the point where gravity overcame them, and then in an as-yet unexplained chain reaction, the rest of each building's members also failed, nearly simultaneously.

?clickhere

3. The existing 9/11 photography shows clearly that this did not occur, because the columns that can be seen flying out of the buildings before and during the collapses, and can later be seen lying or standing in the debris, are clearly UNDEFORMED, i.e., have not experienced any kind of load failure. Here are a few familiar examples:

(Before the collapses)


(During the collapses)






(After the collapses)










4. If there is no evidence of structural load failure, and considerable evidence of structural members that have not experienced load failure, then the buildings cannot have collapsed as a result of load failure. That leaves explosives, an act of Providence, or some unknown technology--in other words, demolition.

5. And that is why the existing photography is conclusive evidence of premeditated murder, which I think we can all agree is a high crime worthy of immediate Congressional investigation and judicial action.

[Taxloss]

1. "Conclusive evidence" at last!

I'd rush that to the FBI NOW. If they don't listen, try a law firm, because money can be made suing the perpetrators.

[dailykoff]

6. Thanks, but I'll be happy if Congress takes an interest.

They might be putting the Pentagon budget on the chopping block. So sorry.

[G Hawes]

92. Surely, you've forwarded this incredible evidence

of yours to Congress by now, haven't you?

Haven't you?

Five years later...

[dailykoff]

144. I haven't, but I'm open to suggestions

as to who to contact and how to express it in a way that won't bring well-armed DHS agents calling.

[G Hawes]

276. Now that we've gained control of the house and the senate

how hard can it be?

Forward your "evidence" and get on with it already. Seriously. What better time? What better circumstances? You could personally bust this vast conspiracy wide open! Go for it, already!

[mrgerbik]

324. awwwwww shadddup n/t

[DoYouEverWonder]

2. As usual

an Octer is first out of the gate to make a few snide remarks.

[Taxloss]

3. Well, here's some less conclusive evidence for you:

Nice curves.

[dailykoff]

4. defenselink.mil?

I can always count on you guys to come up with the most amazing photos.

Anyway what's remarkable about these two shots is how little evidence they show of compression failure, which, as I said above, shows a very distinctive pattern.

What we're seeing here is mainly shearing -- cutting, or in this case, breaking -- and some bending consequent to the quarter-mile drop. But little if any buckling, sorry.

[mirandapriestly]

35. BWAHAHAH, "defenselink" and their FAKE photos

funny how black scorched steel didn't show up in any other photos, lol

[Taxloss]

36. Do you mean the first picture?

Because it's from New Civil Engineer, a British civil engineering weekly. Not Defenselink - that's the obviously forged picture of a guardsman standing on the rubble in Ground Zero.

[William Seger]

40. Yeah

ALL the evidence has been faked. Let's have another "investigation" and ignore all that faked evidence, and instead imagine all the real evidence that must have been covered up. We'll get to the bottom of this.

[Flatulo]

314. Buckling is an elastic failure, is it not?

You could have a buckled beam that structurally failed (ie, became unstable) and be perfectly straight after the critical load is removed.

Of course the elastic failure could lead to plastic deformation if the column remained attached to whatever applied the critical load.

[dailykoff]

315. Not failure buckling, no.

Same with bending. If a column bends or buckles to the point of failure it will surpass the point of elastic deformation. That's my understanding anyway.

[Flatulo]

316. I understand... I was just suggesting that some columns may

have remained straight after the collapse even though they had structurally failed to carry their loads.

Buckling need not cause plastic deformation, if I recall correcly. It's technically a stability failure. The material yield strength need not be exceeded.

A possible explanation for so many apparently straight perimeter columns is that the floor trusses, when impacted by the floors collapsing above it, could have sheared off the angled brackets welded to the perimeter columns, making them effectively twice as long and much more susceptible to buckling.

Once the perimeter column is 'long' enough it would be unable to even support any appreciable load. The column could then just become unstable and snap and fall to the ground.

[dailykoff]

317. No, I don't think it's possible

for a column that has actually buckled to the point of failure to return to its original shape. It will look something like this if it's rigidly connected at both ends, or like a hairpin if it isn't:



The fact is that few if any surviving WTC core columns showed buckling -- I haven't yet seen a photograph of a clearly buckled core column -- and very few surviving perimeter columns showed buckling, which directly contradicts the "progressive" failure mechanism alluded to in the NIST reports, though never directly described (at least not the last time I perused them, which was last summer).

[DoYouEverWonder]

5. Thank you

at least you've provided some substance.

However, according to the OCT theory the steel failed due to the heat of the fires. Are any of those bent pieces pictured, steel from the impact zones that were subjected fire, or are these pieces that were twisted has a result of the building coming down?

[dailykoff]

7. Mostly bent from falling, it looks like. (n/t)

[Taxloss]

9. Any proof of that? n/t

[dailykoff]

11. The proof is in the pictures.

Of course, it helps to know what you're looking at. :)

[Taxloss]

13. Well then, we'll just have to take your word for it, won't we?

I am pretty certain I know what I'm looking at.

[dailykoff]

14. I think we'd better let Congress sort it out, don't you?

In hearings, followed by judicial proceedings. That's the American way after all.

[Taxloss]

15. I would welcome that. n/t

[salvorhardin]

26. But I thought Congress was in on the conspiracy?

Who's part of the nefarious tribe of conspirators and who isn't? Who can you really trust? Oh, this is so confusing.

[DoYouEverWonder]

19. We shouldn't have to

Every steel beam and column in the WTC was individually numbered.

If the WTC was treated like a crime scene and if most of the steel wasn't shipped out to China in such a big hurry, we would be able to find out exactly where those bent pieces came from.

If they were not from the impact or fire zones, then they were bent has a result of the collapse, not the cause of it.

[AZCat]

22. Not true (IMO).

The impacts changed the loading on the structure. This could have caused failure in members not directly damaged by the impact or subsequent fire.

[petgoat]

30. All the steel was marked with stamped ID numbers.

So the photographed pieces of interest could have been
preserved, and their locations identified precisely.

Of course in any proper investigation that would have
been done. But in this investigation, the steel was
shipped off to China and India. So sorry.

[Contrite]

247. Found this--does it help?

The direct blast pressure will result in severe bending of the column, as shown in the figure, in addition to the axial loads that it supports.

http://www.wai.com/AppliedScience/Blast/blast-struct-design.html

Explosive blasts can cause bending.

[dailykoff]

248. Yes, in several ways!

Not only does it help explain the deformations seen in these photos but it also gives several reasons why the construction of the towers was particularly impervious both to collapses and to damage from explosives, which would account for the inordinate quantity used: (a) they had steel frames, (b) they were symmetrical, and (c) they had unusually high shear strength on account of the shear walls used to resist Atlantic hurricanes.

Very informative--great find!

:thumbsup:

[Contrite]

249. Question

Do the photos of bent columns/beams all show outward bending?

Does this look like bending or buckling?

[dailykoff]

250. Now that is a great question.

To be honest I haven't been looking for it, but now that you mention it, several photos of standing perimeter columns do show a distinct outward bending, like this one:



Most of the fallen columns I've seen have been remarkably straight, as in this very large satellite photo, which I take to be evidence that they were sheared apart by lateral forces, i.e. explosions:

link: ?click

I'm going to look through some pages of photos I've bookmarked and see what I can find.

p.s. that looks like bending in the photo. But as far as I know all the WTC columns had hollow rectangular or square cross sections, so my guess is that these curved pieces are beams, or possibly columns from another building:

[Contrite]

251. That photo is a NIST photo and is from the WTC

I should have provided the link: http://wtc.nist.gov/media/gallery.htm#recover

Here is one from a (RW) webblog* that was posted by the blogger in an attempt to counter what Kevin Barrett said about the NIST's "alleged inward buckling" or bending or bowing of columns:



But it shows outward bowing, yes?

(*Okay, in the interest of playing fair, it was screwloosechange, http://screwloosechange.blogspot.com/2006/12/kevin-barrett-on-nist-report.html)

[Bolo Boffin]

252. As the lines show, it's internal bowing.

Just like this picture:

[dailykoff]

253. Whatever it is, it looks like an effect, not a cause.

That goes for your photo too Bolo.

The problem with this particular argument, if I've got it correct, i.e., that this is an example of perimeter column buckling which is supposed to confirm the pancake myth, is that whatever is going on at the perimeter seems pretty clearly to be an effect of what's happening to the core, which is that it's disintegrating, and the top section is starting to rotate.

[Contrite]

254. Okay, so was Kevin talking about the core columns

or the perimeter columns? He was referring to NIST's findings.

[dailykoff]

255. Not sure but I'll look it up

and see if I can come up with a better answer.

Okay from your link it looks like he's talking about the core columns because he mentions the idea of the steel supposedly having lost its fireproofing, which as far as I know applies only to the web joists and core columns.

So I guess that means those three photos of perimter columns supplied by Screw Loose Change are beside the point as well as misleading (they don't show any buckling to speak of), but what else is new?

:shrug:

p.s. I don't think Kevin Barrett gives himself out as an expert on the NIST report so it's typical that they would take his remark and try to mangle it.

[Contrite]

256. Okay, meanwhile, there is this

http://www.debunking911.com/sag.htm

"Putting this irony aside, the real evidence that the core did not move over time is the fact that the other faces showed no signs of the core moving until the collapse.

Before I continue, it's important to distinguish between the events of the moment of collapse and the gradual progression of bowing of the perimeter columns. I am talking about the gradual progression of bowing. The NIST does not disagree with the tilting of the top sections of the towers and that the core was a major part of that. Where the "scholar" differs is that it was the core and not the trusses which caused the tilt/collapse. He needs it to be the core to explain away the bowed columns and still entertain the thought of thermite/thermate.

If the core tilts, pulling the columns in at the impact level in, you would see an equal but opposite reaction from the opposite face. If the east perimeter columns were being pulled in because the core columns tilt, the west would show signs of being pushed out. The top would also tilt, not just when it collapsed but over time as the perimeter is being pulled in. Think about it, the core is connected to all the floors above the impact point. If the trusses were in pristine or even merely slightly sagged condition as suggested by this "scholar", and the core and not the trusses pulled in the perimeter columns, then the core would have tilted pushing out the columns on the roof level. Why is there no sign of this happening? Because it didn't. It's just another attempt at throwing the kitchen sink in to explain this evidence."

They also add, at:

http://www.debunking911.com/jones.htm

Under this photo is the following statement.

"Notice also that most of the steel flung out appears to be straight. If the building had been destroyed by gravity one would expect much of the steel to be buckled.

A real, unbiased peer review might have uncovered some facts. The first is the idea that steel would be more than slightly buckled or buckled at all in a gravity collapse is flawed. You would expect only the columns which initiated the collapse to be buckled. And there is evidence they were."

**************

So here is my question: If the core was "selectively" knocked out; i.e., selective columns were cut/weakened, would that affect every face of the tower or only the face located opposite the specific column(s); that is, would it cause buckling/bowing of the perimeter columns at that location only?

And, if those columns that bowed/buckled were at or near the point of impact, would we only expect to observe this phenomenon there rather than necessarily expecting that other columns were weakened causing bowing/buckling on the other sides? And could it be that an "assist" at this location was sufficient to help to begin the collapse, which afterward became a total collapse due to charges going off at strategic points all around the building the rest of the way? Because it looks to me like the buckling/bowing/bending pictured was at the impact zone only.

[dailykoff]

257. Everything I've ever read on that site

is ass-backward reverse-engineered bunkum picked up from Popular Mechanics and other shills.

1. As to the perimeter column buckling, I don't think there's any way to predict exactly how taking out certain core columns would have affected particular perimeter columns. What's clear is that the perimeter columns were not warping as a result of loads redistributed from failed core columns. If that were the case, there would have been much more pronounced buckling.

Also, the only perimeter columns to experience such warping were between the rotating top chunk and the lower part of the building, and if failing perimeter columns were actually responsible for the collapses, they would have buckled on all collapsed floors, i.e. on all floors, and they did not.

2. The second part about Jones's picture is complete nonsense. If the buildings had actually pancaked or progressively collapsed, both the core and perimeter columns on every collapsed floor (every floor) would have had to buckle, and that clearly did not occur.


p.s. I edited the last one to include an answer

[Contrite]

258. Makes sense to me

And so, do you think that--since the pancaking scenario is ruled out--the load redistribution argument could be confined to a specific area--i.e., affecting just a few perimeter columns owning to a prior selective collapse/weakening of just a few select columns? Or could the truss connections be broken at the core only, maybe on just one or two floors at the impact area, leading to a collapse at the interior edge of the floor only, thus pulling inward on the perimeter columns? Perhaps some but not all trusses supporting the floor could be blown? I did read from at least one survivor account that he saw the ceiling above was sagging (and he was a few floors down from the impact area). Or would all floors on that level necessarily be affected, as they say?

P.S. First visit to that website (and last)--see what kinds of trouble Googling can get you into! I thought it read like bunkum and I wanted some feedback on why what they were saying was in fact bunkum.

[dailykoff]

259. I think what's happening is that the core is gone

or nearly gone and the top chunk of 30 or so floors is beginning to do what it would naturally do, which is rotate in several directions.

If they'd stopped there, what would have happened next is that the top would have either rotated off the building and fallen onto the ground (or a neighboring structure) or simply settled onto the lower part of the building. It didn't because the grand finale started before it could.

But if it had, it would have bent, buckled or sheared most or all of the perimeter columns on the two or three floors in between, and I believe that's what is just beginning to occur in these photos.

[Contrite]

261. Okay, I believe the core was blown too

But why wouldn't the floors not all just start falling in toward the center, pulling the perimeter columns inward from all four directions? I mean if you pull the center support out of something, whatever is attached to the core loses its connection and unless it is rigid enough/firmly attached sufficiently to remain suspended hanging off the outside skeleton, starts to cave in? The trusses were dependent on both the inner and outer columns, were they not? (I work in residential construction and I'm thinking of basic floor truss construction here, which depends on both supporting walls to remain suspended and support the loads above.)

[dailykoff]

264. The floors weren't that heavy for one thing.

The floor assemblies were very lightweight. One floor diaphragm wouldn't have enough nearly mass to pull in the perimeter columns, which were big, robust, and closely spaced. It would be like ice on a pond pulling in the shore.

[Contrite]

265. Well, then

I hardly see how "sagging floors" could have accounted for anything, unless there were enough of them landing one on top of the other and they were heavy enough and maintained their perimeter connections. But if several floors became detached (just) from the core and dropped onto each other, and maintained their perimeter connections would that produce sufficient force to pull the outer columns inward? (My apologies if this has been discussed before; I just started coming to this forum not long ago.)

I like what this person has to say, but while they are discussing the debunked pancake theory, in that they seem to account for the possibility that the core was blown rather than being pulled apart by collapsing floors--versus intact from the start.

http://covertoperations.blogspot.com/2005_09_01_covertoperations_archive.html

"However, seems to me that floor 97 and above could not have simply dropped twelve feet unless there were charges taking out all the supporting columns. If in reality, floor 97 dropped or collapsed because the core columns and outer columns were weakened by fire, and these columns couldn't hold the load of the floor, then there would be a gradual weakening and lowering-- it certainly wouldn't be a free-fall drop for twelve feet. Thus, I think it is impossible that the collapse of this one floor could have started anything like a global collapse.

More importantly, there is simply no way that the top thirteen floors could have dropped all at once. In fact, there is no way in hell that all thirteen floors are going to be detached from the outer columns and the core columns at the same time AND that the core columns are also ALL going to fail at the same time.

I CAN see one floor failing and collapsing (although I would bet that the floor failure would be asymmetrical and the whole floor wouldn't drop). But I can't see one floor collapsing bringing down the whole tower. This makes no bloody sense.

So, does the official pancake collapse model say that the floors collapsed and cascaded down from around the core structure, and that the core initially stayed intact? This could make some sense, although the progressive collapse should have stopped at floors 75 and 76 where there were solid beams holding the floors instead of trusses. The problem is that in videos and photos, we see no signs at all of the core staying intact as the initial floors fall down. Rather there is just an incredibly violent disintegration of the top thirteen floors and a rapid downward explosive global collapse.

Or, does the official pancake collapse model say that the floors collapsed and cascaded down from around the core structure, and that this brought down the core structure at the same time? I think this would have to be the model to account for the video and photographic evidence, but it absolutely makes no sense that the incredibly strong WTC core would collapse from the floor plates that surrounded it falling down."

[dailykoff]

266. LOL, many times, but don't worry.

And you're right, sagging floors wouldn't do jack for several reasons. For example, if a floor collapsed, it would either split in two and hang from each wall, or else become detached from one wall and hang from the other. In either case, it wouldn't "fall" onto the floor beneath at all, but hang like an awning from the walls. No pancaking.

None of this b.s. ever holds up under scrutiny.

[Contrite]

267. Just to point out

I added a quote to the end of my post which you probably didn't see before you answered.

The only point I am really trying to make is whether there was enough weight on the connections of the perimeter columns to pull them inward. If not the floors and their contents alone, what about the added weight of the planes (or what remained in any case), since the bending/buckling seems to be in the impact area? They didn't completely disintegrate because they (reportedly) did find seats with charred bodies in the wreckage (including one body they labeled "possible perp"). Also, were the connections strong enough to hold if the core was taken out first? Just one more thing: were the "buckles" located at the spandrel plates? Is it possible the spandrel plates were "blown" inward instead of outward, producing the bowing seen?

[dailykoff]

268. Very good quote.

As for the NIST, believe it or not they don't go beyond modeling "collapse initiation," and their model for that is farcical. So they forbear to comment on how progressive collapse would actually work.

As for the floors pulling in the perimeter columns, I don't see how it could happen. The perimeter columns were designed to resist huge lateral loads and were also in compression from huge gravity loads. The floor diaphragms were pretty flimsy by comparison. It would be like a single branch pulling down a redwood tree.

[Contrite]

269. So then, getting back to the topic

do you think the inward bending/bowing/buckling observed was possibly produced by explosive blasts directed inward rather than outward? I mean, wouldn't it make sense to blast toward the inside so that the blasts would not be as visible from the outside? And could those same blasts have been designed to detach the floor connections from the perimeter walls?

[dailykoff]

270. You know that's a good question.

The bowing is so slight it's never struck me as having much significance in view of what was happening to the core, but others have theorized that microwave or directed-energy weapons may have been used to effectively melt the entire building. Others have suggested that it's an optical illusion which seems reasonable given how slight it is (I believe this is petgoat's theory).

I haven't watched any videos of this specific event lately so I'm probably missing something important but I will as soon as I get a chance.

[Contrite]

271. Cool

Glad I could ask something worthwhile. I'll look forward to what you find!

On edit, one reason I ask too is that I have seen photos with "bent" spandrel plates attached to "bent" columns.

[Bolo Boffin]

272. Up to five feet of displacement = slight.

:eyes:

[petgoat]

279. That the apparent bowing is an optical illusion due to heat

refraction of the light (like the wavery image you get on a hot road of an approaching car)
is Jim Hoffman's theory, not mine.

And I'm not convinced it's true. But apparently NIST has not refuted it.

The assumption that columns bowing equals columns buckling is not justified.
Where are the buckled columns?

[AZCat]

283. Jim Hoffman apparently doesn't know much...

if he can't figure out why this isn't true.

You do understand that the amount of distortion is dependent on the "length" of the mass of heated gas, right? To take your example - if you're looking at a car or any other distant object along a hot road you have quite a distance where you're looking through a section of heated air. In the case of the towers, only the air outside the exterior of the towers is going to be heated (relatively, of course). This distance is going to produce an insignificant distortion in any photo or video of the towers, not to mention the lack of "laminar" flow in this case that would be necessary to produce consistent distortions along the surface.

[Contrite]

291. I agree that they are bent and not buckled

Everything I have seen looks bent or bowed

[William Seger]

273. The perimeter columns were definitely pulled in

The NIST report has many pictures showing the perimeter columns being pulled in. They also have pictures of floor slabs seen hanging free from the perimeter. If you watch this video, it shows very clearly (at about 5 seconds) what initiated the collapse, the perimeter columns buckling inward:
http://video.google.com/videoplay?docid=-5405555553528290546&q=trinity+wtc+collapse&hl=en

When the perimeter columns buckled, their load was distributed to other perimeter columns and, because of the hat trusses at the top of the building, to the core. An important thing happened then: The top of the tower started to lean toward the wall that started to collapse -- quite a bit in the south tower, but also 3 to 4 degrees in the north tower. That had several critical effects: (1) the center of mass of the top section also shifted toward the collapsing wall, which put a disproportionate load on the core columns on that side, which were already carrying extra load because of the collapsing wall; (2) the only way for the tower top to lean is for the core columns to bend, which reduced their carrying capacity; (3) due to the extra load and the bending, the columns nearest the collapsing wall began to buckle as that side of the building dropped down; (4) simultaneous with all that, the angular momentum of that tilting top put an equal-and-opposite lateral force on the columns holding it up, and this lateral displacement also reduced the carrying capacity of those columns; (5) the core columns nearest the collapsing wall failed next, putting both extra load and more bending on the remaining columns; (6) all of the columns at that level failed "progressively." So it's incorrect to imagine that just the floor sections failed and fell away from the core; that entire level failed (at least, maybe two levels at about the same time) -- not instantaneously, but within no more than a couple of seconds -- and the entire top section fell and began pounding the entire lower tower.

[Contrite]

280. Thanks for all of that, but

I was just now mainly interested in the initial collapse, not the total collapse. What caused the perimeter columns to buckle/bend/bow/pull in, in the first place, since that is the first obvious sign of distress after the impact and the fires? I have read that contrary to NIST the fires weren't hot enough to buckle the steel (even uninsulated) and that the impact damage wasn't enough to weaken the structure to initiate the collapse.

And why do the perimeter columns buckle/bow in rather than out--if the cause is not the floor slabs pulling on them? The pictures showing the slabs hanging free, are they slabs or are they trusses and slabs combined? If trusses and slabs remained attached to the perimeter, why not to the core?

James G. Quintiere, a professor of fire protection engineering at University of Maryland, said he questioned the conclusions, as his analysis showed that in the fires created by the impact, the lightweight floors rose to a temperature high enough to make them separate from the exterior columns. "They have not presented enough evidence," he said.

[Contrite]

286. Versus NIST

NIST concluded that the WTC towers collapsed because: (1) the impact of the planes severed and damaged support columns, dislodged fireproofing insulation coating the steel floor trusses and steel columns, and widely dispersed jet fuel over multiple floors; and (2) the subsequent unusually large jet-fuel ignited multi-floor fires (which reached temperatures as high as 1,000 degrees Celsius) significantly weakened the floors and columns with dislodged fireproofing to the point where floors sagged and pulled inward on the perimeter columns. This led to the inward bowing of the perimeter columns and failure of the south face of WTC 1 and the east face of WTC 2, initiating the collapse of each of the towers. Both photographic and video evidence—as well as accounts from the New York Police Department aviation unit during a half-hour period prior to collapse—support this sequence for each tower.

NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram below). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.

[William Seger]

288. What we know, for sure...

... is that the perimeter columns were bending inward -- which began well before the collapse, and progressed leading up to the collapse -- and that the visible part of the collapse began with the total buckling (inward) of the perimeter columns. Since there weren't any cameras inside the building, anything that anyone says about how that happened is, to some degree, speculation. However, NIST's "educated guess" is also based on an elaborate computer model, not just general engineering knowledge, and certainly not on pure imagination and ignorance like the speculations here. So, at this point, I'd give their explanation the most weight, until some more elaborate and accurate analysis shows something different. You might even go so far as to say the inward buckling is "unexplained," but with so many different ways that it could have happened naturally, it certainly isn't so "unexplainable" that there is any need to assume explosives were required. I think it's pretty clear that that's just a dead end for "truthers" (except amongst those who simply prefer that explanation).

[petgoat]

281. You claim buckled perimeter columns overstressed the core.

That's complete horseshit.

In a wind, the windward perimeter columns would have been in tension, pulling
the hat truss down, not in compression. The core was thus taking the weight
of all the floors on the windward side.

As far as the hat truss and the core are concerned, the buckled perimeter
columns only simulate the effect of wind on that side. The notion that the
failure of buckled perimeter columns to provide compressive support overloaded
the core is ridiculous. The core was designed to take that load.

You claim that the hat truss leans in the direction of the allegedly buckled
perimeter columns. Wrong. The hat truss is restrained tensilely by the
perimeter columns on the other side of the tower. How can it lean?



The core was designed to take most of (and thus with the safety factor the entire)
load of the building. It had to take it, because in any wind at all, the windward
side would be in tension, throwing the load of the windward side floors on the core.

[William Seger]

287. Nonsense

> In a wind, the windward perimeter columns would have been in tension, pulling
the hat truss down, not in compression. The core was thus taking the weight
of all the floors on the windward side.

Completely wrong. I encouraged you to do you own investigation of how the building handled wind loads, so I'm not going to repeat over and over and over how the perimeter walls were designed to carry all of the wind loads, even if there had been no core and no hat trusses. The only reason I'm responding is to correct your screwy notion that tension on the windward side would somehow pull down on the hat trusses and dump all the gravity load on the core columns on that same side. The bending of the tower due to wind would have exactly the same effect on the core "tube" as it had on the perimeter tube: "tension" (or most likely just a reduction in gravity loads) on the windward side and compression on the leeward side. The gravity-load shifting due to wind-load bending would be entirely to the leeward side of the building. In effect, because of the rigidity of the square perimeter tube, the wind would be trying to blow the tower over by tipping it up on that opposite perimeter wall foundation, which, if it could actually do that, would put all of the weight of the building on that opposite wall foundation -- not on the windward side core columns.

[petgoat]

289. To hear you tell it, the core is just extra strong elevator guides.

your screwy notion that tension on the windward side would somehow pull down on the hat trusses and dump all the gravity load on the core columns on that same side.

I said the core was taking the weight of all the windward side floors, not that the core
on the windward side was taking the weight of all the floors--which is obviously not so.
I'm sorry my statement was ambiguous, but since your interpretation of it is obviously
absurd and since I clarified the point at the bottom of the post (and since you ignored
the central point of the post) I'll suppose you didn't give it much thought.

The gravity-load shifting due to wind-load bending would be entirely to the leeward side of the building.

Not entirely. Obviously the core columns can not escape their floor loads under any circumstances.
There is no mechanism for transferring floor loads across the core columns to the perimeter columns on the other side.

You have not responded to the central point. A 767-sized hole in the perimeter was no problem
because the hat truss was tensilely restrained by the columns on the other side. But you act like
a few allegedly buckled columns causes a structural crisis and a leaning tower block. If you
want to make that case, you have to show us how the allegedly buckled columns created a problem
greater than what the tower had already beat. Your alarmist claim that a few buckled columns
made collapse inevitable is absurd.

The tower block can not lean to the allegedly buckled side. The hat truss is tied down by the
perimeter columns on the other side. The tilt would have to lift the entire weight of all the
floors and all the thousand-foot perimeter columns on the opposite side.

How many buckled perimeter columns are you claiming here?

[Contrite]

290. Analogy?

I can punch a hole in the side of my house and a hole in the floor and still my roof won't cave in because the roof trusses are resting on the perimeter walls, and the load is carried by remaining perimeter studs and the corners, as well as the headers/top plates at the top of the damaged perimeter wall. I can even knock out the beams carrying additional floor loads and still, unless the beams and/or floor joists/trusses completely pull out of the space between the sill plates and the rim joists, and the corners still stand, the roof will not fall in. More of the load will transfer from the roof trusses to the opposite perimeter wall but the house will remain upright and not lean to the compromised perimeter wall.

[William Seger]

292. Screwy

> I said the core was taking the weight of all the windward side floors, not that the core
on the windward side was taking the weight of all the floors--which is obviously not so.
I'm sorry my statement was ambiguous, but since your interpretation of it is obviously
absurd and since I clarified the point at the bottom of the post (and since you ignored
the central point of the post) I'll suppose you didn't give it much thought

Oh, I understood what you said just fine, and it didn't take much thought to see how ridiculous it was. I'll say it again: Under wind loading, the core would experience exactly the same type of forces as the perimeter: "tension" on the windward side and compression on the leeward side. No, the core would certainly not take any of the gravity load from the perimeter columns on that same side. Gravity loads would increase on the leeward side, and only on that side.

> You have not responded to the central point. A 767-sized hole in the perimeter was no problem
because the hat truss was tensilely restrained by the columns on the other side.

The basic problem was that the hat trusses could not redistribute gravity loads uniformly. If they could, the tower would have almost certainly not collapsed. But the uneven distribution caused some columns to be overloaded even though other columns had plenty of capacity left.

> But you act like a few allegedly buckled columns causes a structural crisis and a leaning tower block.

Both the buckling and the tilt were directly observed. Here's how this is supposed to work: Any proffered theories need to explain all the things that were directly observed. Theories based on imagination and bogus physics that don't explain the things that were directly observed are useless.

> The tower block can not lean to the allegedly buckled side. The hat truss is tied down by the
perimeter columns on the other side. The tilt would have to lift the entire weight of all the
floors and all the thousand-foot perimeter columns on the opposite side.

Your first assertion contradicts the observation: Both towers did tilt toward the collapsing wall, so any valid theory needs to account for that. And the one and only way that the top could tilt is if the core columns on that side somehow got shorter. I claim they simply buckled from being overloaded, more so than the remaining core columns. At that point, I really don't know if it was the core columns or the perimeter columns that were acting as the fulcrum of the tilt, but it doesn't matter since neither could do so for long. Once the core columns nearest the collapsing wall began to buckle and allow that side of the building to fall, yes that was a crisis, and all the columns at that level were doomed in a "progressive" horizontal failure.

> How many buckled perimeter columns are you claiming here?

Do your own research: Read the NIST report.

[petgoat]

293. Screwy is right

the core would experience exactly the same type of forces as the perimeter:
"tension" on the windward side

No matter what happened, the peripheral core columns would have to bear the weight
of the floors attached to them. When the windward perimeter columns were place in
tension, the outer portion of the floors hang from the perimeter columns, which
hangs from the hat truss, which stresses the core columns on the windward side
and the leeward side and the leeward perimeter columns.

You are trying to transform the WTC into a rotten cracker box that can be induced to
crumple by a small injury to one side.

Both towers did tilt toward the collapsing wall, so any valid theory needs to
account for that.

Thermite accounts for that. The antenna drop on tower two shows that the core
and the hat truss failed before the collapse began.

the one and only way that the top could tilt is if the core columns on that side
somehow got shorter.

And the failure of a few perimeter columns does not account for that.

Do your own research

Oh gee, the specifics of your claim are a secret? How very NISTian of you.

[Contrite]

294. Is this right?

I read that the 5-story hat truss was actually helping the perimeter wall to remain upright, something it was not designed to do because its primary purpose was to help stabilize the building under stress from wind load, rather than pulling it apart/pushing it down.

"The purpose of the hat truss was to minimize the sway of the towers in the wind by rigidly connecting the tops of the core and perimeter tube. After the aircraft flew into the perimeter tube, the hat truss served a purpose it was not designed for, and it helped the towers remain standing in their crippled state."

http://72.14.203.104/search?q=cache:RyY6KXYEn3AJ:132.236.67.210/EngrWords/issues/ew01/StevensonC_PR1.pdf+function+of+the+WTC+hat+trusses&hl=en&gl=us&ct=clnk&cd=8

So as I understand it, the hat truss spanned the entire building, was supported by the core and the perimeter columns hung from it; it tied the outer walls to the central columns but it didn't help to support them.

So when one side of the building was damaged by the plane impact, it seems to me that the hat truss would be relieved of some tension on that side but not tip or compress the core because of it. If the floor truss system--beams connecting perimeter columns to the core (which were actually very heavy, I read) via transfer trusses, with perpendicular trusses or "decks" (which were relatively light) that ran perpendicular to these, forming a grid--did in fact pull inward on the perimeter columns, how could that happen unless the core were also failing or gone? Also, if the hat truss were in fact helping to hold up the damaged perimeter wall upright why would that happen? And how? Did the truss beams buckle? I understood that they did not, but instead twisted from their weight and weight of debris on them. How could they twist unless they were not connected to the core? Why would pressure on the respective core columns cause them also to buckle and why would that bring the entire core down? NIST says core columns were sheared at the area of the impact, so how would they be affected by downward pressure from the trusses at all? Or does this mean that the trusses lost their core column support and therefore pulled down/in on the perimeter walls? And if they pulled down on them, why did portions of the perimeter walls fly up and out?

Manuel Garcia summarizes NIST's report:

"The columns along one face of the building were sheared for a height of several floors, as were many of the columns at the core", then asserting that the jet fuel weakened the core further, leading to its collapse. "The damaged core columns in the impact zone could no longer hold up all the weight they were meant to carry. The core columns in the upper block now found it necessary to partially hang from the hat truss. The hat truss pressed down much more forcefully on the perimeter columns, transferring the load of the hanging weight. The added compression of the perimeter columns could only be distributed to the three undamaged faces, and because of the irregularity of the damage one face assumed a much higher load than the other two."

So this indicates that not only the perimeter walls but also the core columns were partially hanging from the hat truss and that instead of the hat truss helping to hold up the perimeter walls, it instead acted as a downward force on the side that collapsed.

He continues to describe that the buckling was caused by that and the heat of the fire:

"The floors in the impact zone sagged because of broken joints to central columns, heat causing their metal framing to soften, weaken and expand; also because of the weight of debris fallen from above. The sagging floors twisted their joints to the perimeter columns (on the three intact faces); the length of column above a floor joint being twisted inward. For one face of the building, the combined stress of the original weight above it, the added compression from the hat truss, and the torque from the sagging floors were too much. Its perimeter beams were bent inward to the point of failure, and they buckled."

Notice he blames broken joints and heat, indicating that the trusses were hanging free from the column but remained attached to the perimeter. Note also that he uses the term "sagging floors", yet I read that the floors did not sag significantly in the tests that were performed and NIST has not proved that they were. Yet the entire "sagging floor" theory seems to rest largely on the heat from the fires. Also, if a floor sags, it pulls both the perimeter columns and core columns toward the center of the floor. Because the core columns are stronger than the perimeter, the perimeter is the side that gets pulled in. So, how could the sagging floors have anything to do with the core?


http://www.counterpunch.org/physic11282006.html

[Contrite]

296. Gordon Ross expands on this

http://forum.physorg.com/index.php?act=Print&client=printer&f=10&t=7444

If the rectangular box of perimeter columns was so unstable as to be unable to withstand buckling for longer than a few seconds after removal of the floors how could they then withstand the moments involved in a rotation over extended angles? How did the walls disassociate from each other at or about the corners in order to allow the walls to "peel apart like a banana" and fall perpendicularly outwards from each other?

Similarly if floor to perimeter column connections were strong enough to transmit forces sufficient to cause inward buckling of the outer columns over prolonged periods of time while being thermally weakened and forced by aircraft impact damage to carry a higher proportion and magnitude of load, then why did their eventual dislocation, by whatever mechanism, not have a visible plastic response in the remaining long sections that you have evidenced. You would tend to think that if the floor to column connections were so strong then the act of dislocation would not have left long sections of perimeter columns showing little distortion, ready to topple over largely intact and reach relatively distant points.
The more you look, the more you find.

Also:

The mid wall perimeter columns from adjacent walls fell outwards in perpendicular directions and in doing so would have to overcome the resistance of the spandrel plates.

In short the progress of the collapse below the aircraft impact level was facilitated by detaching the floor to column connections below this level, and by attacking the spandrel plates connecting the corner perimeter columns to the mid wall perimeter columns. This is accompanied both in time and place by the expulsions of dust/debris. The mid wall perimeter columns below the aircraft impact, fall outwards as the upper section is pulled down inside them by the falling core.

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

I have been wondering about the spandrel plates. They were on the inside of the perimeter columns. It seems to me that this would contribute to the columns resisting inward buckling.

[William Seger]

297. That quote about the hat trusses is not accurate

> "The purpose of the hat truss was to minimize the sway of the towers in the wind by rigidly connecting the tops of the core and perimeter tube. After the aircraft flew into the perimeter tube, the hat truss served a purpose it was not designed for, and it helped the towers remain standing in their crippled state."

That looks like a student research paper, but the assumption that the hat trusses were "to minimize the sway of the towers in the wind by rigidly connecting the tops of the core and perimeter tube" is incorrect. The hat trusses consisted of a lot of cross-bracing within the core columns, for several levels, but there were only 4 triangular "outriggers" connecting the core to each perimeter wall, and all those connections were at the same level. Although the core cross-bracing would make that part of the core very rigid, it wasn't to minimize swaying.

The hat trusses were actually designed to allow the towers to carry the massive antenna. (The original design anticipated antenna on both towers.) From the NIST report, for example:

The purpose of the hat truss was to support gravity and wind loads on the antenna. It was not designed to resist lateral forces on the towers, and, in an undamaged state, it did not have a significant role in carrying gravity loads. Lateral loads due to wind were distributed to the framed-tube system via diaphragm action of the floor system. The hat truss was connected to each perimeter face at only four points, all at the same level (at the 108th floor just below the concrete floor slab). The 47 core columns were connected to diagonal elements, heavier transfer beams, or smaller beam elements in the hat truss. Most of the core columns extended to the roof level, but four core columns, which were only minimally connected to the hat truss, terminated at floor 110. The hat truss provided minimal redistribution of loads (less than 10 percent) from perimeter columns to core columns. Most of the load redistributed due to aircraft impact damage occurred on the external face through vierendeel action.

So the outriggers would help keep the antenna from blowing over in the wind, but they weren't part of the wind-load design of the building. That's pretty similar to descriptions I've read elsewhere in more technical articles, and the lead engineer, Leslie Robertson, consulted for NIST to develop the structural database and helped with their model, so I believe that description is accurate (especially since it makes more sense). The perimeter "tube" didn't need to be "rigidly" connected to the core to resist swaying; the perimeter tube itself needed to be rigid enough to act like a square beam, for the full height of the tower.

> Note also that he uses the term "sagging floors", yet I read that the floors did not sag significantly in the tests that were performed and NIST has not proved that they were. Yet the entire "sagging floor" theory seems to rest largely on the heat from the fires. Also, if a floor sags, it pulls both the perimeter columns and core columns toward the center of the floor.

You need to be very careful about what your read on the "truth" sites. NIST did not try to test the floor joists for sagging. They were only testing the fireproofing to see if it met code specifications, so the longest joist they tested was only about half as long as the long joists in the towers, and they had the original fireproofing so there wasn't any testing of how the long joists would have behaved if a lot of fireproofing had been ripped off. Anyway, sagging during the fires is really only half the story; the leading theory is that the joists pulled the columns in when they began cooling and shortening.

As for also pulling on the core columns, the floors in the core were supported by beams across the core, so they were restrained from being pulled outward, while the perimeter columns were not restrained from being pulled inward.

[Contrite]

298. Thanks--responses

Kevin Ryan:

What is not reasonable is the degree of sagging NIST used in its computer models compared with the amounts its physical tests showed. Whereas the 35-foot floor model sagged only a few inches in the middle after two hours in a high-temperature furnace, NIST's computer model showed a sagging of 54 inches.

And refers to NIST's floor-sag-induced inward bowing of perimeter columns the "triple double bare steel computer result." He is referring to the fact that NIST's computer model doubled the height of the unsupported wall sections, doubled the temperatures, doubled the duration of the stress, and ignored the effect of insulation.

http://911research.wtc7.net/reviews/kevin_ryan/newstandard.html

Other than the video, NIST left us with only some vague statements about a few sagging floors suddenly destroying two hundred super-strong perimeter columns and forty core columns. But since sagging floors do not weigh more than non-sagging floors, it is difficult to see how this might occur, especially so uniformly. NIST claimed the perimeter columns saw increased loads of between 0 and 25% due to the damage, but it never reconciled this with the original claim that these columns could resist 2000% increases in live load. And the outward-buckling theory, suggested by Thornton, was changed again to inward buckling—apparently the forces involved were never well defined. Additionally, NIST suggested that the documents that would support testing of the steel components, along with documents containing Skilling’s jet-fuel-fire analysis, could not be found.<26>

http://www.mindfully.org/Reform/2006/911-WTC-NIST-Lies30mar06.htm

Garcia then offers even more detail about the collapse initiation sequence than NIST was ever ready to give, while simultaneously using some of the same fuzzy claims about sagging floors. How much did the floors sag in the physical tests? And for comparison, how much sagging was used in the computer model we are not allowed to see? There are some important differences here.

By saying "the sagging floors twisted their joints to the perimeter columns", Garcia now appears to be telling us that it was increased torque (twisting), and not pure lateral (pull in) loads, that caused the external columns to fail. We can't be sure if he checked with NIST on this before publication, but seeing as NIST had to actually disconnect their virtual floors from their virtual columns in order to demonstrate any kind of inward failure, none of this seems to matter anyway.

Instead, he proceeds to explain the importance of the tower's supportive hat truss, but without noting that NIST simply ignored the hat truss in the critical segments of their all-important computer model.

http://911review.com/articles/ryan/counterpunch.html

Journal of 9/11 Studies concurs:

The decision to exclude the hat truss from the structural/thermal response simulations was a significant omission. The sequence of failed truss seats leading to pull-in forces on the exterior columns is central to NIST’s theory but not explained or supported by simulation.

By not including the hat truss, the primary load path for core column load redistribution was removed, leaving the core floors, which typically provided a secondary load path.

And, although NIST claims “the core was effective in redistributing loads from damaged core columns to adjacent core columns when load path through the hat truss could not be developed due to either severed columns or column splices,” (NCSTAR 1-6 p231 para3) still, this was a major deviation from the actual construction. Considering how much emphasis NIST places on the hat truss elsewhere in its reports, it is misleading to downplay the effects it would have had in supporting the damaged core.

The decision to exclude the hat truss from the structural/thermal response simulations was a significant omission. The sequence of failed truss seats leading to pull-in forces on the exterior columns is central to NIST’s theory but not explained or supported by simulation.

http://www.journalof911studies.com/volume/200612/NIST-WTC-Investigation.pdf

"Hat Truss" Design (architectural definition)

A structural steel truss located at the top of the building to provide a rigid frame for resisting lateral wind loads and reducing building movement (sway).

http://www.aiahouston.org/cote/AIACOTE-glossary.htm

[William Seger]

299. Quick comment

I might address some of the other points in your post later when I have more time, but just one quick one:

> Other than the video, ...

To me, the real crux of the "sagging" issue is that any valid theory must explain what's seen in the videos and pics, and it must satisfy the logical requirement that the columns simply couldn't bend inward like that if the floors had been intact. The whole design of the towers vitally depended on the floors preventing the perimeter columns from bending. Furthermore, the theory has to explain two more observations: the inward bending was only observed on floors where there had been impact damage and/or fires; and it happened gradually over time, not all at once. So explanations such as saying that the core was destroyed with thermite, which pulled the columns in as it fell, don't really work because: that would happen suddenly; the effects would be seen from that point all the way up to the top of the tower; and collapse would most likely have immediately followed.

So, at this point, whatever criticisms people want to level at NIST's "sagging" theory, it's still the only logical one I've seen.

[Contrite]

300. Again, thanks for the reply

I agree with your criteria, and that is why I prefer Gordon Ross's theory, which to me is the only logical one I've seen.

It does, as you say, explain what's seen in the videos and photographic evidence, and explains to my satisfaction the phenomenon of the inward bending of the perimeter columns. It does not, however, attribute it to sagging floors but rather explains how the inward bending occurred, gradually, through the first of a four-phase demolition. He also addresses the hat truss vis a vis the action on the core, in a way that makes sense.

Phase 1

The object of Phase 1 was to weaken the Tower by attacking the central core structure, disassociating the core structure columns at a level below that of the impact .

Effects of phase one

The result of a failure of the core such as this prior to collapse initiation would be to allow the mass of the core and floors above the failure to act downwards on the hat truss and the load would then be transferred to act vertically on the perimeter columns.

The downward movement of the upper disassociated core structure would also allow a horizontal force to act on the mid wall perimeter columns through the floors to cause inward bowing of the mid wall perimeter columns.

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

1/ The perimeter structure could carry all of the vertical mass above it at any point with ability to spare. So immediate collapse would not occur even in the event of a failure of all of the load carrying ability of the core.

2/ Similarly the corners alone of the perimeter walls could theoretically support the total vertical mass above them. The corners can be regarded as the most rigid and strongest part of a structure. Note how in demolished or fallen down buildings, a corner is often the last part standing.

3/ The design of the towers was such that the floor trusses connected outwards from the faces of the rectangular core structure to connect only with the mid wall perimeter columns. The floor trusses carrying the floor sections in each corner were not connected directly from the core to the perimeter, but rather from the perimeter to a transfer truss and then to the core. The relevance of this is that if the core pulled downwards it would act effectively only through the floors to a proportion of the perimeter columns - those in the middle of each wall inside the lines of the core. The perimeter columns at and about the corners, those outside the line of the core, would not be connected via the floors directly to the core, but via the floors via the transfer truss to the core, and would therefore be less affected by a force caused by downward movement of the core structure.

Perimeter column bowing

Note that the bowing identified by NIST was only on one side of each tower. It was not generalised across all of the tower.
For the example of WTC1, NIST report bowing only on the South face, storeys 94 - 100. For WTC2 bowing only on the East face, storeys 77 - 83.
Note that for both Towers only the MID-WALL perimeter columns were bowed. The corners were not visibly bowed.

If the bowing was being caused by a pure vertical movement of the upper core structure, that is with no tilt, the bowing would be present on all four sides.

Further doubt is thrown on the NIST theory that the bowing was caused by sagging floors by examination of the photographs contained in their own report on WTC2, which shows floors sagging in a direction perpendicular to that which would be required to cause the bowing.

http://wtc.nist.gov/WTC_Conf_Sep13-15/session6/6McAllister.pdf

If the bowing was caused as NIST describe, then that would require that the floors are still connected to the East perimeter wall columns in order to pull them in, but the report shows disassociation of many of these connections. Those floor areas could not both be disconnected and contribute to a pulling action. This reduction in the number of floor to column connections would severely limit the total load which could be applied

Note also that while there is evidence in their report to show sagging did take place perpendicular to the direction required, there is no evidence presented that any sagging took place actually in the direction required.

The animation shown to the left demonstrates graphically that all of the core structure and perimeter structure must bend to accomodate the tilt. Sagging floors cannot be regarded as being responsible for this level of pre-collapse damage.

[William Seger]

303. I definitely don't agree that Ross' hypothesis is logical

For his Phase I hypothesis, he does not explain why bowing was seen on only one wall if the core was "disassociated." Worse, I don't see any way to explain why the floors would pull the columns in on only a couple of floors, rather than all the way up, if the reason was that the core had dropped. Also, he's hypothesizing that the core dropped enough to pull the columns in several feet laterally (which would require the core moving downward far more than several feet) and that the hat trusses distributed the core load to the perimeter walls. How does he imagine that both of those things happened, and how does he get to that conclusion based only on the evidence that the columns were pulled in on only a couple of floors?

Already, in Phase I, his hypothesis makes no sense at all to me, so I didn't even read the rest of it.

As for the criticism that the NIST report shows floors disconnected from the same walls that were pulled in, you need to take a closer look at which floors were seen to be hanging and which ones are assumed to have pulled the columns in. That NIST link you provided shows hanging floors seen through the 80th and 82nd floor windows, so those would be the 81st and 83rd floor slabs. That's not inconsistent with the theory that the 80th floor pulled the columns in, with possible help from the 82nd floor. In fact. if the 81st floor had collapsed (completely or partially) to put extra load on the 80th floor, and the 81st floor was no longer there to provide inward restraint on those columns, that would help to explain why those columns were pulled in, not contradict it.

> The animation shown to the left demonstrates graphically that all of the core structure and perimeter structure must bend to accomodate the tilt. Sagging floors cannot be regarded as being responsible for this level of pre-collapse damage.

I definitely disagree with that assertion. The sagging floors pulled the perimeter columns in, which made it easier for them to buckle, which put more load on the core columns on that side (because the outriggers could not redistribute that load uniformly across the core), which caused the core columns on that side to begin to buckle (although presumably not to their plastic limit). That apparently happened fairly slowly, but as the top began to tilt, all the forces that were causing the tilt would have gotten worse as the perimeter columns buckled more and the center of mass of the top section moved toward the core columns that were beginning to buckle. The bending itself reduced the ability of the core columns to reduce buckling, so the buckling of the core gradually progressed to the other core columns.

[Contrite]

304. He does explain why bowing was on one side only . . .

if you continue reading his hypothesis:

"If the bowing was being caused by a pure vertical movement of the upper core structure, that is with no tilt, the bowing would be present on all four sides.

Angle cut columns

Example of an Angle Cut Vertical Column


However if a 45-degree cut is made in the core columns, there will also be a horizontal component to the movement of the bottom of the upper core section and a consequent tilt in the upper core section. The floors will only transmit an inward pulling action through the floors to one wall, with a compressive action on the opposite floors and a twisting action on the floors on the adjacent sides.

It was the reaction created by a, say, 45-degree cut through the core columns which began, both the tilting action of the upper sections, and the bowing of one perimeter wall in each Tower."


He also explains how only a portion of the floors would be affected, not the entire floor:

"Note the important point mentioned above that the design of the towers was such that the floor trusses connected outwards to connect directly only with the mid-wall perimeter columns. The relevance of this is that the core pulling downwards would act effectively only through the floors to a proportion of the perimeter columns - those in the middle of each wall inside the lines of the core. The corners which were the strongest section of the perimeter structure were not placed directly under this load. The perimeter columns at and about the corners, those outside the line of the core, would not be connected via the floors directly to the core, but via the floors via the transfer truss to the core, and would therefore be less affected by a force caused by downward movement of the core structure."

So, while the slabs from floors 81 and 83 could be visible through the 80th and 82nd floor windows, it would not necessarily be the entire floor bearing down on the floors below, just the portions attached to the perimeter columns in the middle. Notice that the "hanging objects" do not appear to extend through to the corners.

Notice, also, as regards the hat truss, that he states the point of failure would be below the area of the impact.

"The object of Phase 1 was to weaken the Tower by attacking the central core structure, disassociating the core structure columns at a level below that of the impact (Plane 1)."

Effects of phase one

"The result of a failure of the core such as this prior to collapse initiation would be to allow the mass of the core and floors above the failure to act downwards on the hat truss and the load would then be transferred to act vertically on the perimeter columns."

Notice he does allow that the failure/disassociation could be at the point of impact, but that if that were the case the core would have to be moving downward more slowly than the perimeter and floors.

"It could be argued that the still photograph captures the core structure in the act of falling and therefore the disassociation did in fact originate at the aircraft level. This cannot be ruled out. However, this would necessitate that the core structure was moving bodily downwards at a slower speed than the outside perimeter and floors. The only circumstance which would allow this to happen would be a failure of the core structure at a level close to the ground. (Which could correlate to blast explosions heard at/below ground level and also the smoke clouds which arose at the base prior to collapse.) The cause of this failure must be independent of the collapse front because the failure must happen before the collapse front reached the failure level in order to allow the different speeds of collapse of the core structure and perimeter."

Irrespective of whether the core structure is moving downwards or is stationary, the photograph remains evidence that there was indeed a total horizontal failure of the core structure at some point below the aircraft impact.

[Contrite]

305. Also, Phase II targets the hat truss again

Effects of Phase two

The result of these attacks was a radical reduction in the corners ability to carry load and this resulted in failures at the points of attack, the corners of the perimeter structure. The full weight of the tower above these attacks was then transferred to the midwall perimeter columns. These were already suffering under both vertical and horizontal forces and immediately suffered failure between the points of attack. The hat truss was disassociated allowing the upper core structure to drop downwards and thus pull inwards on the perimeter structure.

[William Seger]

306. Nope, not buying that

First, according to people on a professional welders forum, that column was cut with a torch, and here's convincing evidence that columns standing in the rubble were cut like that for removal:




The welders noted (from a closer picture) that the column you're referring to appears to have been cut with a torch from the outside on three sides, and then when the column bent over, the lower side was cut from the top:



But Ross' hypothesis is still completely illogical (and I had read at least that part before I responded), because:

(1) The bowing happened slowly over a relatively long period of time, which he doesn't explain.

(2) One of the walls had bowed in 55 inches by the time it buckled, which is hard to explain by the action he speculates.

{3) The core couldn't pull in just the columns in the middle of the wall unless that section of the floor slab and cross-trusses had broken free of the surrounding floor structure (they weren't made of rubber) and it's not at all clear that the pulling force alone would have done that rather than be distributed by the floor diaphragm action.

(4) The combination vertical and horizontal action he speculates from cutting the columns at 45 degrees couldn't possibly pull in just one wall without also having observable effects on the other three walls -- i.e. pushing the opposite wall out and displacing the side wall columns laterally -- and no such bending was observed.

(5) He doesn't explain how only one or two floors were pulled in, but not the floors above that, since they were also attached to the core.

Even without addressing those serious problems in his hypothesis, Ross' explanation sounds like a "just so" story to explain (some of) the observations, rather than being a practical plan to bring down the building. It seems to me that any attempt to correct the above problems would result in an hypothesis that would be so contrived and convoluted as to be highly implausible, and would appear to have no purpose except to better fit the observations. By comparison, NIST's explanation is simple and believable, and Ross' attempts to make it seem implausible fail.

[Contrite]

307. Answers

(1) I don't think he states or implies that the bowing happened quickly. He talks about it in phases I-II. How long does Phase I last? During this time the upper floors are exerting pressure on the perimeter walls, but the corners and the hat truss are still continuing to help provide support. How long does Phase II last? The corners and hat truss undergo attack in Phase II, and the added vertical force exacerbates the bowing of the perimeter walls.

He also notes that "the collapse front, plane 2 does not begin to move downwards immediately, there is a distinct time difference between the first movement of the upper section and the first movement of the collapse front."

(2) Why is it hard to speculate the extent of the bowing in his scenario vis a vis NIST's? NIST was not able to duplicate the extent of bowing in their modeling and had to exaggerate their vertical span and temperature parameters in order to achieve even 10 inches of sag. I would speculate that Ross' theory needs to be modeled as well in order to determine the validity of his assumptions.

(3) Does NIST account for this in their sagging model? Ross says:

"If the bowing was caused as NIST describe, then that would require that the floors are still connected to the East perimeter wall columns in order to pull them in, but the report shows disassociation of many of these connections. Those floor areas could not both be disconnected and contribute to a pulling action. This reduction in the number of floor to column connections would severely limit the total load which could be applied.

Note also that while there is evidence in their report to show sagging did take place perpendicular to the direction required, there is no evidence presented that any sagging took place actually in the direction required."

But, to address Ross' model specifically: He stresses that the trusses at the mid-wall of the perimeter were connected to the core via transfer trusses and the corners to the core via the floor and the transfer trusses. He also says that the disassociation from the core would (probably) be below the point of impact (allowing for the speeds for the collapse front and the core). The way I understand it, in Phase I, the upper core is still acting as a unit, but disassociated from the core; the floors are still connected to the transfer trusses and to one another, and the corners remain attached via the floor to the transfer trusses. (The floor to mid-wall perimeter and core column connections of the lower structure were broken--along with additional attacks on the corners--in Phase III, to progress the collapse.)

(4) He speculates that NIST's theory would show bowing on four sides, yet NIST only discusses bowing on one side: "Note that the bowing identified by NIST was only on one side of each tower. It was not generalised across all of the tower. For the example of WTC1, NIST report bowing only on the South face, storeys 94 - 100. For WTC2 bowing only on the East face, storeys 77 - 83. Note that for both towers only the MID-WALL perimeter columns were bowed. The corners were not visibly bowed. If the bowing was being caused by a pure vertical movement of the upper core structure, that is with no tilt, the bowing would be present on all four sides."

Also recall that he points out the evidence of NIST's sagging occurs in a direction perpendicular to what their theory should actually produce--yet, the bowing did not occur on opposite walls.

(5) See above.

The photo of the 45-degree angle cut appears to be heavily debated. He seems to take some care with it, calling it merely an "example" of such a cut. I am sure that it does look very similar to a cut made by a welders torch and also sure that such cuts were made in the process of clearing debris. I would also imagine that any photos that show true explosive action on steel would have been part of the debris removed and would not be in a widely circulated photograph. I have read that there were rather tight controls on use of cameras at Ground Zero.

In summary, it seems plausible to me that:

+ Phase one weakened the structure by attacking the central core structure, disassociating the entire structure at a level below that of the impact at a horizontal plane (upper core remains a unit but is not attached to the core; floors do not collapse because they are connected to the transfer trusses; the corners of the structure and hat truss continue to provide support; allows the mass of the core and floors above the failure to act downwards on the hat truss and the load would then be transferred to act vertically on the perimeter columns; the downward movement of the upper disassociated core structure would also allow a horizontal force to act on the mid-wall perimeter columns through the floors to cause inward bowing of the mid-wall perimeter columns.)

+ Phase two initiated the collapse of the perimeter structure by attacking the four corners of the towers on two storeys {Plane 2 and Plane 3} (the full weight of the tower above these attacks was then transferred to the mid-wall perimeter columns) and disassociation of the hat truss (allows the upper core falls downward and pulls inward on the perimeter). Note: The upper section of WTC2 appears upon first examination to tilt as one piece about a fulcrum located at the aircraft impact level. Closer examination reveals that there is a distinct bend in the line of the corner columns and the top storeys of the upper section, those which are above the bend do tilt, but in the section below, more obscured by smoke, there is less, or even no, rotational movement in the line of columns. The upper section did not necessarily display the behaviour expected by some commentators and in particular it has been said that the conservation of angular momentum was not observed. Because the core failure occurred at a lower level than aircraft impact the core structure projecting below the impact level would give a "keel" action to the upper section as it fell.

+ Phase three progressed the collapse by disassociating the floor to mid-wall perimeter column connections and two vertical lines of spandrel plates at each tower corner, and by continued attacks upon the corners as in phase 2 (Prevents lower floors from providing resistance; the mid-wall perimeter columns from adjacent walls fell outwards in perpendicular directions and in doing so would have to overcome the resistance of the spandrel plates.)

+ Phase four completed the collapse by attacking the remaining central core structure at lower levels and disassociating the horizontal bracing.

[William Seger]

308. Okay, guess that about covers it

I simply don't find Ross' hypothesis logical or plausible, nor do I see any need for such a contrivance since I think NIST's is logical, plausible, and relatively very simple. You have a different opinion, but I don't suppose there's anything to be gained by repeating the same things over and over, so let's let it go at that.

[Contrite]

309. Agreed--and thanks very much for the discussion.

It was quite informative and I appreciate all of your considered inputs!

[Ezlivin]

318. Proof of cutting charges in your last photo (from an metal fabricator with 25 years experience)

If you are an experienced torch cutter, light or heavy metal doesn’t matter, the principles are much the same. There are several facts that indicate it was not a torch cut:

1. No cut from a torch accumulates that much hanging slag. Most slag is blown away; this volume would indicate melting with abundant, directed heat but with little or no air pressure eliminating blow torch possibility.


2. Slag cools too quickly. To drip that long, with the beam itself vertical, that much slag would separate and fall to the ground, and would never drip that far even with that bad a cut. The suggested explanation of Thermate with no air pressure at a much higher temperature would account for this.


3. No experienced torch cutter would take a diagonal cut on 4" thick steel tube. And why would even an inexperienced one do so? There would be no possible reason to do it where a horizontal cut is possible, even if above the cut was bent in the direction towards the lower horizontal cut. And the upper horizontal cut can be seen to be cut also on a downward angle thru the steel. No one would angle from horizontal on 4" thick steel and increase the cut to 5 or 6" thick.


4. No one would cut on an angle thinking that it will cause a standing structure to fall a certain direction, just ask any lumberjack.


5. Any metal cutter would also question why the rear cut is not a straight line and it dips drastically in one spot, this indicates possibly the remains of a round cut which would allow inserting Thermate charges inside of the tube to conceal them (more on this regarding the second photo).


6. Someone implied to me that the cutter would have his hand inside the tube cutting the last horizontal leg to explain the slag on the lower horizontal cut. Impossible, that would mean that 3 legs were cut, and then the beam bent so he could reach inside? You would see evidence of the bend if it was bent before final cutting, and you would see evidence of bending at the conclusion of the cut as the weight takes control. Highly unlikely, and there would be few experienced heavy gauge metal cutters who would agree with the torch cut theory.

Source

Regarding photo above purportedly showing workers making a diagonal cut:

This photo has been posted by 9/11 debunkers that supposedly shows a torch cutter making the same diagonal tube cut. This photo either proves that a torch cutter is performing the operation of cutting the column or, he is tasked with completing the cut that wasn't successful during the demolition:

1. If he started the cut on the right side, why didn't he finish it? I would say it's because he's been assigned the task finishing a cut that was mysteriously ½ done for some reason, maybe thermate that didn't complete the cut? If there were hundreds of such planted “melts” throughout the building, it's possible that there was an error factor of some that would not burn correctly, but not enough of a percentage to prevent or slow the buildings collapse, except maybe points right near the ground that were basically protected once debris filled in around them. What else supports this?


2. I've marked the photo wondering what these other burns are? Did the cutter start on the left top, then decide to move to the bottom, then decide, “Oh, I guess I'll start on this one over here instead”? And why did he not remove the aluminum façade on the 2 burn attempts on the left tube? Such as on the right one?


3. Given the acrid yellow smoke, it is clearly not steel that is being cut by the worker. Galvanized steel or aluminum burns yellow, steel burns white as shown in the 3rd photo which is a 24” cut of steel which burns white as it most always does (photo source http://www.opetrol.com/gallery.html). Even the burn stains on the aluminum cuts on the right, color match the acrid smoke being produced by the cut work on the left. So it looks to me like the cutter is simply finishing the cutting away of the aluminum façade which is evidently cut away on the far right of the photo to expose the steel hidden beneath it.


4. Aluminum doesn't cut with an acetylene torch it simply melts and gets blown away by the air pressure. A plasma cutter is the preferred method of cutting aluminum and gives off blue/white sparks and smoke. This worker is most likely using torches he may have on the platform since his task is to cut the heavy beams beneath the aluminum (a Plasma cutter needs electricity). The jagged, unclean edge of the cut aluminum on the right side supports this. A plasma cutter would not leave this kind of edge or yellow smoke or stain.


5. Façade on the outside only so the steel cut in photo 2 indicates cut angled from inside to outside of the building. If the evidence of a possible hole in photo 1 on the high backside indicates where thermate could be installed on the inside of the tube, then the operation would mean they could do this just about anywhere inside the building and covered up by simply repairing sheetrock walls after insertion.


6. The testimony from this iron worker would solve some of this mystery, but without his testimony to confirm otherwise, the facts show that he is clearly making ready to finish cuts that didn't succeed on their own.


7. Additional supporting evidence includes molten steel found in the rubble for 12 weeks after 9/11. To date, only thermate explains this, the government provides no explanation for this and a lack of evidence is as important is factual evidence.

[LARED]

320. If I was guessing that steel was cut with a carbon arc. n/t

[William Seger]

295. Round and round and round and round

I can't figure out from the muddle of your first paragraph if you are changing your claim or if you are still insisting that the core would would somehow take on all the gravity load on the windward side. If you are still insisting it would, you are simply wrong, period. For (hopefully) the last time, the floor diaphragms held both the perimeter and the core in the shape of two square tubes, so wind loading would cause the tower to bend as a single unit, with tension on one side of the center plane and compression on the other.

> You are trying to transform the WTC into a rotten cracker box that can be induced to crumple by a small injury to one side.

You are trying to transform both the WTC and the sequence of events into things they weren't, with an apparently endless series of unsubstantiated assertions and screwy notions. I am simply trying to disabuse you of those notions. Entire walls bucked, and given the severed and damaged perimeter columns on other walls and in the core, calling that a "small injury" is absurd.

> Thermite accounts for that.

Yeah, if only you could figure out some practical way to cut vertical columns with thermite; and I suppose the Death Star beam weapon and mini-nukes that don't produce radiation and all sorts of other science fiction would "explain" it too. Problem is, there is absolutely no need for those kinds of speculations when the collapse can be completely understood as a structural failure. Again, the fact that you don't understand it will keep you searching for alternate explanations forever, but your problem is finding reasons why anyone should take you seriously. "Physically impossible" claims from people who clearly don't understand simple mechanics aren't very convincing. For example:

> > the one and only way that the top could tilt is if the core columns on that side
somehow got shorter.

> And the failure of a few perimeter columns does not account for that.

Failure of all the columns along one side is not a "few," and again, there were already severed and damaged columns on other walls and the core, so the buckling of the walls certainly does explain it: The core columns nearest the buckled walls began to buckle from overloading (which you are trying to pretend either didn't happen or that the columns were 20x stronger than they needed to be), and once that buckling started happening, all the forces that initiated that buckling became worse, so the buckling quickly became worse until the columns failed.

> Oh gee, the specifics of your claim are a secret? How very NISTian of you.

Bullshit. You asked how many columns I "assumed" buckled. There's no need for my assumption when NIST was very specific about how many and which ones, and the report is certainly no "secret." It appears you weren't sincere in your question.

[dailykoff]

260. p.s. I don't think the trusses had anything to do with the collapses.

They really played no structural role apart from supporting the floor diaphragms (the rings outside the cores). If they were warping or failing, that would simply have been an effect either of the initial damage or the subsequent disintegration of the buildings.

[dailykoff]

262. p.p.s. another of many reasons the official tale is impossible:

even if crashes and fires could account for the destruction of the cores between the top chunks and the sections beneath (which they can't), there's no way to account for the complete disintegration of those lower 80 or so floors.

[Bolo Boffin]

263. Besides momentum, of course. n/t

[Name removed]

275. Deleted message

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

[Name removed]

277. Deleted message

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

[William Seger]

274. That's because...

> I don't think the trusses had anything to do with the collapses.

That's because you don't understand the building design, even a little bit. The floor joists were the only thing holding the perimeter columns from buckling in the direction perpendicular to the wall. I really don't understand why you keep posting your thoughts on the collapse when you don't understand even the simple stuff.

[G Hawes]

278. Yet, you've never posted a single thing that refutes them

Not a single thing.

Just your personal "opinion" with nothing to back it up. No expertise, no credentials, no nothing.

[Taxloss]

8. The first is impact zone buckling.

The second, I don't know, just a very hefty piece of very bent steel.

[William Seger]

28. Two suggestions:

> However, according to the OCT theory the steel failed due to the heat of the fires.

1. Read the NIST summary for a more precise description of what initiated the collapse.

2. When you're sure you understand what it says, watch this video: http://video.google.com/videoplay?docid=-5405555553528290546

[wildbilln864]

10. are you pretending...

you've proved something tax?

[Taxloss]

12. I've proved the presence of bent and buckled structural steel. n/t

[dailykoff]

21. Bent, yes. Buckled, no.

It's an important distinction because bending can be produced simply by falling, while buckling is produced exlusively by compression.

[William Seger]

29. Buckling IS bending

"Buckling" is bending produced by a particular failure mode, and it doesn't necessarly produce an "S" curve like the one in your top photo. A structural engineer might be able to look at a photo and accurately guess if a bend in a column was produced by buckling. Convince me that you can, too; tell me what factors lead you to guess that the bending in Taxloss' photo was not caused by buckling.

[AZCat]

53. The "S" curve is actually less common than others.

The first failure mode resembles a parabola (it's actually half of a sinusoidal curve) and is the most common, although higher failure modes do occur (with the frequency depending on various factors).

[dailykoff]

60. No, they're related but entirely distinct failure modes.

A quick way to illustrate the difference is to compare a soda can bent in half to one crushed with your foot. Pretty noticible difference.

I'll try to come up with something more scientific later.

[AZCat]

61. Now you're talking about something entirely different.

How can you justify thin cylindrical shell buckling as an analogy for column buckling?

[dailykoff]

146. Not so different.

No, the towers were not constructed out of Coke cans (thank you, Captain Obvious), but both the perimeter and core columns did have hollow cross sections, so their behavior under compression would not be so very different.

In any case, it's a conceptual illustration, as I'm sure you gathered.

[William Seger]

149. It's been over a week now...

... since you posted your "conclusive evidence of premeditated murder" and it seems you STILL haven't done any research at all. I realize this is the 9/11 board, so not many here would expect you to actually do any researh before making that claim, but you promised me you were going to "try to come up with something more scientific later." Couldn't find it?

> but both the perimeter and core columns did have hollow cross sections, so their behavior under compression would not be so very different.

In any case, it's a conceptual illustration, as I'm sure you gathered.

There are several reasons why "their behavior under compression" would "be so very different" that your "conceptual comparison" is silly and pointless. I'm still waiting for you to explain how you determined that the columns in Taxloss' photo aren't buckling, since those perimeter columns certainly look buckled to me.

[dailykoff]

150. It hasn't, but never mind.

I posted the thread on Sunday and the "more scientific" remark on Monday, and today's Friday. As to your various complaints:

1) For a more scientific explanation of what buckling is and how it differs from bending, go here:

http://www.du.edu/~jcalvert/tech/machines/buckling.htm

2) If you have "several reasons" why the soda can illustration is silly and pointless, please post them.

3) The reasons the columns in Taxloss's photos aren't buckled are: a) in the second photo, the noticeably bent and twisted pieces aren't columns (as I explained in my post just below), and b) in the top photo, the bending occurs mainly at the connections, and buckling is lateral displacement occurring between connections, not at the connections (as explained in the link above).

[William Seger]

153. That's interesting. You should read it when you get a chance

> For a more scientific explanation of what buckling is and how it differs from bending, go here:

Like this? "With any larger load, the least disturbance would cause the column to bend sideways with an indefinitely large displacement; that is, it would buckle."

It also explains the difference in buckling if a column is "clamped" (rigidly connected at the top and bottom, like your top photo) and "pinned" (constrained from moving laterally at both ends, but free to rotate). You would even see a diagram showing buckling in a pinned column that strongly resembles the bending of the perimeter columns behind the policeman in Taxloss' photo.

> If you have "several reasons" why the soda can illustration is silly and pointless, please post them.

Well, if you actually understood the description on that page of buckling in a "slender column" you would immediately understand why that doesn't apply to a short fat "column" like a can. Instead, what applies is a very extreme case of what's described at the bottom of the page: "If the walls of the pipe are thin, another type of failure can occur, local buckling, in which the side of the pipe under compression when it deflects slightly buckles over a short distance, which is not surprising in view of the ratio of length to thickness."

[dailykoff]

154. Still mixing up bending and buckling I see.

Yes, I noticed that little patch of thin ice and I wondered if you'd be dim enough to fall through it. Sure enough. Well, let's see if I can pull you out:

Bending occurs when force is applied perpendicularly to a member, e.g., wind against a tree, or lateral force against a column. If it is fixed at one end, like a tree, it will bend or break like a tree in a windstorm. If it is fixed at two ends it will either bow in a sine curve, bend like a can, or break, depending on how much force is applied and how it it distributed.

Buckling occurs when force is applied axially to a member, i.e., parallel to the member. The result is lateral displacement between the connections. When the website says such compressive loading "cause(s) the column to bend sideways with an indefinitely large displacement," they're using "bend" in the common, not technical sense, which is unfortunate, but not uncommon. Nevertheless, they're talking about buckling, not bending.

Incidentally the reason why the gentle sine curve seen in the fallen perimeter wall in the large defenselink photo indicates bending rather than buckling is that the connections in the WTC were not pinned, but rigid (clamped), and buckling would therefore not have manifested itself as a sine curve.

p.s. someday when you're older I'll tell you about shearing.

[LARED]

155. Bull!

Incidentally the reason why the gentle sine curve seen in the fallen perimeter wall in the large defenselink photo indicates bending rather than buckling is that the connections in the WTC were not pinned, but rigid (clamped),

The floor joists in the WTC were not rigid connections.

[dailykoff]

158. Please see below. (n/t)

[LARED]

160. All I see is more bull (n/t)

[dailykoff]

162. I was talking about my contribution. (n/t)

[LARED]

164. Yes, I'm aware of that (n/t)

[dailykoff]

166. Good, then you're also aware

that you got your little buddy up a tree.

p.s. I think he could use a ladder.

[William Seger]

171. Seems to me

... that LARED simply understood what I was getting at, whereas I seriously doubt that you ever will.

[William Seger]

156. Ah, some progress at last. Now just one more step.

I see that, after a little research, you now seem to agree with my "Buckling IS bending" post -- that buckling IS bending produced by a particular failure mode, not "two different things" that can easily be distinguished by looking at a photo. I also see some glimmer of hope that you are beginning to suspect there might be something wrong with your original argument, in that you now recognize that buckling doesn't always look like your top photo. Of course, the point here is not so much to make you publicly admit your ignorance, but to improve your own personal understanding of why your "conclusive evidence of premeditated murder" is a despicable piece of bullshit. So, let's proceed:

> Incidentally the reason why the gentle sine curve seen in the fallen perimeter wall in the large defenselink photo indicates bending rather than buckling is that the connections in the WTC were not pinned, but rigid (clamped), and buckling would therefore not have manifested itself as a sine curve.

Exactly the point, at last: They weren't "clamped!" They were not rigidly connected at the ends like the column in your top photo. They were held horizontally in one direction by the spandrel plates, which would be rigid, but they were held in place in the other horizontal direction only by the floor joists, which wasn't a rigid connection: it was just the joist seats bolted to an angle. So, the columns would have behaved like pinned columns in that direction because they would fail in that mode first. But still, most of the perimeter columns did not buckle, because they were also bolted together, end to end, and that bolting wasn't at the same points that they were constrained horizontally. When the compressive forces caused the columns to react like columns pinned by the floor joists, in most cases it appears that the bolted connections were weaker than the steel, so those connections broke before the columns could buckle.

Get it now?

[dailykoff]

157. You're saying the column-to-column connections weren't rigid?

That's rich. As if the buildings would have stood.

:rofl:

Anyway, this is getting ridiculous. If you want to persist in your mixed-up misunderstandings, fine. There's only so much I can do and I've done it.

[William Seger]

159. "Getting ridiculous"? It already was

... starting with your OP.

> You're saying the column-to-column connections weren't rigid?

Actually, if you will please try to read more carefully, the point under discussion is the buckling behavior of the columns between the their horizontally-constrained ends (i.e. at the floor levels), not the bolted connections. The joist connections were not rigid, so the columns would fail first like pinned columns in the direction perpendicular to the wall and the spandrel plates, which were rigid connections. That is, they would have failed that way (and did in some cases), if the bolted connections were strong enough to withstand the bending, which doesn't appear to be the general case.

> There's only so much I can do and I've done it.

Yes, you have: you've made a total jackass of yourself by claiming to have "conclusive evidence of premeditated murder" based only on your own ignorance.

[dailykoff]

161. The column-to-column connections were most assuredly rigid.

The web-joist connections have nothing to do with it, and you shouldn't take helpful suggestions from people who know even less about a subject than you do.

[William Seger]

165. Please stop trying to pretend that you understand any of this

Clearly, you do not, so you're just embarrassing yourself by not knowing when to quit. Please go back and read that page you linked to again, or better yet look for other pages that have better descriptions of column buckling. Columns buckle between the points at which they are restrained laterally by other horizontal structural members. The type of buckling depends on the conditions of those horizontal restraints: they are considered "clamped" if those restraints are rigid enough to resist column rotation at that point under buckling conditions, or "pinned" if they are not -- they will allow the column to rotate at those horizontal restraint points. The "rigid" column splices have absolutely nothing to do with this, because A) those are not at the points at which the columns were restrained horizontally -- they were between the floors -- and B) we're talking about the rigidity of the connections to the horizontal members, anyway.

> The web-joist connections have nothing to do with it

Completely wrong; they have everything to do with the perimeter column buckling, in two different scenarios. One is that those were the only things holding the columns from buckling outward under normal loading, so if any of those joist connections broke, the column effectively became twice as long -- from the floor above to the floor below -- and if you had understood that page you linked to, you would understand that a column twice as long will have 1/4 the buckling resistance. (That's actually what appears to have happened in Taxloss' photo; the columns are buckled end-to-end, not between the spandrel plates.) The second scenario is the one we're discussing here: If a joist connection did not break, it would hold the column laterally, but it had essentially no rigidity to prevent the column from rotating, so the column would act as a pinned column at that point, having approximately 1/2 the buckling resistance of a "clamped" column.

If you aren't quite finished making a fool of yourself on this issue, then try again. Otherwise, we might move on to the issue you've been dodging: Why did most of the perimeter columns and about half the core columns not buckle at all? This is a key part of your original argument (and all that we have determined here is that you wouldn't recognize buckling if you saw it, because you don't understand it). I suggested a hint in a post below, and I recommended that you think about it before replying. Maybe this discussion of buckling has clarified your thinking about the conditions under which a column would not buckle, so have you rethought that yet?

[dailykoff]

167. Keep flailing.

I just sent for help.

:rofl:

Oh and the floor plates were welded to the spandrels, but they don't mention that in Popular Mechanics, do they?

[William Seger]

169. (Misplaced reply delete)

[William Seger]

170. So you aren't yet finished making a fool of yourself

... apparently because "rigidity" is yet another concept that you do not understand. For the purposes under discussion, it makes absolutely no difference whether the joist seats were welded or bolted to the angles, so there's nothing to be gained by arguing about that. The point is that "rigidity" is a relative concept. If you simply tried to bend those angle brackets by hand, you might call them "rigid." If the top of the column were free and you tried to rotate the column with enough lateral force, and the angle bracket bent before the column did, then that is not a "rigid" connection. To say that those connections were "rigid" with respect to buckling forces is to say that you think the columns would bend before the angles bent. Does that help you to understand how idiotic your statement is?

[dailykoff]

145. p.s. it helps to distinguish between columns and beams.

If you'll notice, most if not all the columns in the second photo are still rifle-straight; it's only the beams -- i.e., the horizontal members, which were considerably less robust as they bore much smaller loads -- that are twisted and bent.

For example: the piece that the guard is atanding on looks like part of a core column, and it's still straight.

The long twisted piece that crosses the photo just below him, however, is clearly a beam, not a column -- you can tell because it's attached to a column at the right edge of the photo.

That twisted piece in lower left front of the photo is also a beam, not a column. (The columns were boxes, not I-beams.)

p.s. the top picture does seem to show a bundle of perimeter columns, but they appear to be bent, rather than buckled, most likely from the blast or fall.

[treestar]

111. That always seems to be the first thing noticeable about the threads

The OCTer resorts to snide remarks and insults first, tries invoking and using the memories of those who died, etc.

If there were an answer, it would be possible to explain it. When the person just wants to have faith in what he/she has been told, there is no answer except the emotional.

[HughMoran]

331. As usual, you have nothing but a snide remark to anyone who disagrees with you

With is interesting since you have no scientific capabilities whatsoever.

I LOL.

[MervinFerd]

16. Yep. Proof at last! How could I have been so stupid as to trust....

the opinion of all the structural engineers of the world, when--all the time--CONCLUSIVE PROOF was just sitting there? Waiting for an industrious Conspiracy Hobbyist to dig it up in a Google search.

Holy Jesus! How stupid can this get?

[Name removed]

17. Deleted message

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

[Name removed]

18. Deleted message

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

[dailykoff]

20. That is a very good question.

But I'm not a therapist, so I really can't say why you persist in such delusional thinking.

[MervinFerd]

23. If there is nothing debatable, there is nothing to debate.

CONCLUSIVE PROOF!

That's a crock, pretty much WHO says it.

In this case......

[MervinFerd]

24. And, ad hominem arguments....

are the last refuge of the Conspiracy Theorist.

[frylock]

43. with textbook examples posted by MervinFerd..

king of the ad-hom attack.

[Anarcho-Socialist]

25. How do we know...

...that structural engineers aren't holographic projections by NASA at the behest of Bushco?

[MervinFerd]

39. Holographic Structural Engineers.

Yes, very probably.

I have long held that the -towers- were actually holographic projections.

Someone recently pointed out that this would provide a motive for simulated destruction of the towers--before Mr. Silverstein could build an -actual- building on the site, he had to provide a convincing destruction of the -alleged- towers.

I am thinking that, in all Dungeon posts referring to the Towers, we should put "Tower" in quotes, or reference them as "the supposed Towers" to highlight the ludicrous claim that there were actually 1000 ft tall towers at that spot.

[Anarcho-Socialist]

50. You're right of course

What is the probability that 1000 ft tall towers exist on any given square mile of earth? The probability of such a thing is incredibly low. Yes bushco and the msm would have us believe that those tall buildings existed in NYC. The very fact that they strongly assert this should be cause for alarm. Yet people seem to buy the bushco line on this. Wake up people!!

[petgoat]

31. Your "all the srtructural engineers in the world" meme is silly.

"All the structural engineers in the world" believed the ludicrous
zipper theory, which was contested only by tinfoilers until NIST
decided the zipper theory was ludicrous.

Then all the structural engineers without a peep of protest adopted
the NIST theory.

I suppose you don't see anything wrong with this?

[William Seger]

33. Your zipper is stuck

> ... ludicrous... ludicrous...

[petgoat]

34. Are you deliberately misconstruing the point?

I'm glad everyone agrees that the zipper theory is ludicrous.

The point is, that "all the structural engineers in the world"
accepted it without a peep despite the fact that it was ludicrous.

And then accepted its overthrow without defending it.

In other words, the supposition that their silence means that
they concur in any meaningful way with the official explanations
is illegitimate.

[William Seger]

38. Obviously, we don't agree

... and this is the last time I'll tell you why we don't agree: You don't know what you're talking about.

There was absolutely no way for anyone to tell whether or not the "zipper theory" was plausible (much less "ludicrous") without a detailed analysis of the connection design of the joists to the exterior columns, and without studying the evidence of how the buildings collapsed. People who declared it "ludicrous" without doing that analysis were talking through their asses, period, just like dailykoff is doing here. Furthermore, you continue to call it "ludicrous" because A) you mistakenly assume that the theory had anything to do with the joist connections to the interior columns, and B) you mistakenly assume that the connections to the interior columns must have been precisely as strong as the connections to the exterior columns, despite the fact that those connections were a different design. So, it's your "analysis" that's ludicrous. That's not how people who really want to understand things think; that's how people with an agenda think. Furthermore, you continually accuse NIST of simply coming up with a predeterimined conclusion while ignoring the fact that they actually studied the "zipper theory" and all the available evidence from the collapse, and they simply came to the conclusion that the "zipper theory" was not the most probable explanation.

In short, the reasons why so many people think conspiracy theorists are ludicrous zooms right over your head.

[petgoat]

42. we don't

you mistakenly assume that the theory had anything to do with the
joist connections to the interior columns

If the zipper theory does not have to do with the core clips, then it
can not explain why the core came down. Since it purported to explain the
collapse, I must suppose that it assumes the floors tore the core down.

you mistakenly assume that the connections to the interior columns must
have been precisely as strong as the connections to the exterior columns

It is the usual practice to support both ends of a truss with seats of
reasonably consistent strength. If there was some reason to build the outer
ones in a flimsy fashion and to overbuild the core ones, I have not heard
it.

that's how people with an agenda think.

You're projecting. I accepted the zipper theory for three years. I stopped
believing it not because of an agenda but because I perceived that it required
the perimeter clips to be flimsy and the core clips to be super strong.

Speaking of agendas, NIST came to the study with the charge to improve fire
safety, thus assuming that the fires caused the collapse, because otherwise
there would be no reason for the study.

you continually accuse NIST of simply coming up with a predeterimined
conclusion

They declined to consider evidence that was outside the scope of the fire-induced
collapse model. Under the circumstances, zipper and sagging truss theories are
just different flavors of kool-aid.

the reasons why so many people think conspiracy theorists are ludicrous zooms
right over your head.

You're just playing with words. The application of the CT term is inappropriate
to discussion of the shortcomings of the official investigation, which shortcomings
are, after all, facts.

[petgoat]

44. Thanks for highlighting the "core point"

which has led me to a new perception:

Neither the zipper theory nor the NIST theory tells us
why the core fell down.

Under the zipper theory, the floors should have simply peeled
off from the core, which at some point, weakened by random
insults to its external columns by falling debris, may have
suffered sufficient losses to its lateral integrity and toppled.

WTC2 would have toppled E or W. WFC was 600 feet away W and
1 Liberty Plaza was 550 feet away E--well within range of
possible destruction from a toppling core section.

WTC1 would have toppled N or S. WTC7 and the Verizon
Building were maybe 530 feet away.

This suggests a reason to use explosives on the core EVEN IF
THE FIRES WOULD HAVE BEEN SUFFICIENT TO BRING THE BUILDINGS
DOWN.

I love my horse. Why would I beat it?

[William Seger]

45. Two questions:

1) What held the core columns in their vertical position?

2) If they aren't laterally restrained every 12 feet, as designed, what would you expect to happen to them? (Hint: Ask Engineer dailykoff what causes buckling, and how column length affects buckling resistance.)

[petgoat]

46. two anwers

What held the core columns in their vertical position?

Inertia, and balanced forces.

If they aren't laterally restrained every 12 feet, as designed

They were restrained. There were floors in the cores and heavy girders
and, in some floors at least, diagonal bracing. In effect the core was
a giant vertical truss.

http://911research.wtc7.net/wtc/evidence/photos/wtc12consenr.html

The vertical truss would have been most damaged by falling debris
on its long (130') side. At some point, 700 feet of asymmetrically damaged
vertical truss might have been unable to stabilize itself laterally, and
it would have started to lean, pulling itself over. 130 Cedar Street was
660 feet from WTC1.

Each of the towers had buildings on two sides vulnerable to destruction by
a toppling core.

This is why explosives or thermite had to be used on the core. Thermite
could have been planted INSIDE the hollow columns. By the time it burned
through the base plates, it would have burned through the sides as well.

[LARED]

47. You should at least learn the meaning of the words you use

You are using the term girder and truss incorrectly.

Also mind explaining what the hell inertia and balanced forces has to do with holding the core vertically.

[petgoat]

48. learn the meaning

I know what a girder is, I know what a vertical truss is.

Inertia and balanced forces are freshman physics concepts
explaining why things stay where they are until the forces
necessary to accelerate them are applied.

[Name removed]

52. Deleted message

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

[William Seger]

54. I guess you need another hint or two

1. According to the FEMA investigators (who had all the time they wanted to inspect the steel, despite your "wisked away to China" nonsense), most of the exterior columns and about half the core columns broke at their bolted joints without suffering permanent bending. This simply indicates that the ends of the columns were not laterally restrained enough to buckle, which is easy enough to understand if you simply watch the things holding the tops of the columns in place -- the floor slabs, both inside and outside the core -- being destroyed as the collapse progresses. The rest of the columns (despite Engineer dailykoff's dramtic "proof") buckled purely from compression if they were restrained enough, or otherwise bent from the lateral forces of the collapsing floors pulling on them while they were near their elastic limit from compression. The basic cause of ALL of this, however, was...

(almost like turning over the last letter on Wheel of Fortune):

2. As soon as the collapse began (most probably just as NIST describes it, after actually studying it), the core (like the rest of the building) was taking a pounding which exceeded its load-carrying capacity, despite your imaginary "giant vertical truss" design. All we're really talking about here is different failure modes.

< This is why explosives or thermite had to be used on the core.

Ummm.... bullshit. Nothing "had to be used" except gravity.

[petgoat]

55. I guess you're just reinforcing the silly "pile driver" theory

with your claim that the core was "taking a pounding."

Your point that most of the columns simply snapped at the joints
is irrelevant to what caused collapse initiation. And had
the numbers been checked as the pieces came off the pile, and
had the relevant pieces been set aside, then there might not be
any controversy about what caused the collapse.

The steel that should have told the tale most certainly WAS
destroyed, because NIST doesn't have it, FEMA doesn't have it;
nobody has the steel that would prove the case.

The core certainly was a vertical truss, and there was nothing
imaginary about it. What else do you call 47 steel box columns
joined by lateral girders and some diagonal braces? Maybe "a
hollow steel shaft"?

[William Seger]

62. What "controversy"?

Now you're getting ludicrous and silly if you don't understand why the core took a pounding in the collapse. Do you think you can balance a brick on your head? How about if I drop a brick from 12 feet on your head? How about from hundreds of feet?

Look, we happen to be talking about technical issues here, petgoat. Apparently that means something different to me than it does to you. Now, I'm not a structural engineer, but I did work for 5 years as a structural draftsman in several engineering offices, so I do have some familiarity with the subject. But that's not particularly important since I'm not relying on my own expertise; I only claim that I can reasonably follow and understand what the experts say. So, on one side of this "controversy" are not only the 200 experts who participated in the NIST study, but also some large but unknown number of experts who apparently agree with the conclusions. You speculate that none of them were paying much attention and were quite willing to accept anything NIST said; but based on the engineers that I worked with, I speculate that you are completely wrong. Every engineer I worked with took great interest in every structural failure that happened, and they would frequently discuss failures that had happened decades ago. To think that they would not be looking closely at the most spectacular structural failure in history is ludicrous and silly.

Now, on the other side of this "controversy" there's a whole slew of paranoids who apparently would rather believe just about anything other than the "official story," but there is not a single qualified expert who can describe in technical terms acceptable to all those other experts what you're trying to say here with pseudo-technical babble.

Sorry, but I don't see where there's any real "controversy" here.

> The core certainly was a vertical truss, and there was nothing imaginary about it.

Perfect example: You have no idea what you're talking about here, but you just keep talking and talking. You posted a picture of the construction of a tower, apparently hoping that I would mistake those temporary crane towers on the corners of the core and being some kind of "vertical truss." Show me one technical description of the towers that calls the core a "vertical truss." The core was designed to carry vertical loads -- not the bending and torsion that trusses are designed for -- and that design assumed that the core columns were held in place primarily by the floors, inside and outside the core. Those floors were destroyed in the collapse.

What caused the core to collapse after the initiation described by NIST? You'll get the same answer as the last time this came up: The general answer is called "progressive horizontal failure." Thanks to the spandrel plates and the hat trusses, the building above the damaged floors was rigid enough to attempt to redistribute the loads of the failed columns to immediately adjacent columns and to the core columns. That's why the building didn't collapse immediately when the plane hit. But then the sagging floors pulled the remaining exterior columns in, and columns that are no longer vertical will rapidly loose their ability to carry load. Those that were already near their load limit because of the initial redistribution would have failed first. The structure attempted to redistribute the loads again, but it was just too much: The columns that caught that load failed almost immediately and the load was transferred somewhere else, until all the columns on at least one level failed. The core columns were certainly weakened somewhat by the fire -- even at 250 degrees C there is some weakening, and there are good reasons to think that some columns did get hotter than that -- but there are a lot of engineers (including Greening) who think the core would have failed after the collapse started even if they hadn't veen weakened by fire, simply because too many core columns had been damaged by the plane strike. This progressive failure did NOT happen "instantaneously" -- which is why both towers started tilting before collapsing -- but it only took a few seconds. This phenomenon is not surprising to people who have studied it, and it certainly wasn't invented on 9/11.

I'm not going to ask you if you understand this description, but do you understand that your inability to understand it is NOT a valid argument against it? Do you understand why your incesant need to keep arguing and arguing even though you don't understand it is getting to be very annoying?

[petgoat]

65. I understand your post just fine, thank you.

Your analogy of the brick on the head is very silly, because if the upper part
of the tower was a brick, the lower part of the tower was not a head but another
brick, one that as you know was built far more robustly than the upper part.

Your claim that every one of the NIST experts endorses all the work in the report
is absurd. Obviously most of them participated only in limited parts of the study.
To claim that they endorse parts of the report in which they did not participate
is illogical.

Your claim that the NIST report is disputed only by "a slew of paranoids" is
simply an ad hominem attack. Try dealing with some of the points in Jim Hoffman's
"Building a Better Mirage" or Kevin Ryan's analysis of the "Bush Science" in the
NIST report.

As to whether engineers are interested in the report, the record speaks for itself:
NOBODY would criticize the ludicrous zipper theory, and nobody defended it when it
was overthrown.

You have no idea what you're talking about here

I know perfectly well what I'm talking about. I did not try to pass off that picture
as anything. I have tended to believe that those lattices at the corner are simply
temporary crane towers, but I have been told by an architect that they are in fact
moment frames. Until I find out for sure, the issue will be open for me.

That the core was designed to carry vertical loads does not change the fact that it
functions as a vertical truss in the context in which I was discussing it: the context
of a core stripped of its floors and its connections to the perimeter columns, which
must be laterally braced by itself. It is then a vertical truss, even if it was not
designed to be one. As a vertical truss exceeding the limits of its stability, it
will tend to topple.

As to the rest of your babble from NIST, though I understand it just fine,
the fact is you have no evidence for it.

[William Seger]

69. Brick collision

>> How about if I drop a brick from 12 feet on your head?

> Your analogy of the brick on the head is very silly, because if the upper part of the tower was a brick, the lower part of the tower was not a head but another brick

Yes, if I drop a brick on your head, it would be a lot like hitting another brick.

So, according to you if the brick below had been designed to carry the weight of the brick above plus a safety factor, but it gets hit with that brick dropped from 12 feet, everything should be fine as long as the brick below doesn't understand that it just got pounded?

[petgoat]

72. It's not a brick. Look at the pictures. The top of the towers

exploded into dust and pick-up-sticks.

[petgoat]

76. It's not a brick, it's a birds nest, and a birds nest can not

demolish a fence post, no matter how hard it hits it.

[William Seger]

100. Q.E.D.

Brick theory confirmed.

[petgoat]

105. OK, it's a brick. A pulverized brick. You can drop that on my

head from 1000 feet any day.

[Ezlivin]

319. "I'm not a structural engineer..."

Get thee hence to the Architects & Engineers for 9/11 Truth website do some reading, then join their forum.

Then you will get the chance to tell structural engineers and architects your theories of how the buildings were constructed and why they fell.

Of course it may be a bit frightening to be around engineers and architects who do not buy into the official theories (nor are hoping for lucrative government contracts as those who did the "official" investigation were).

[William Seger]

322. Been there

It was quite a disappointment -- nothing but the same recycled, debunked-a-thousand-times crapola that hundreds of other sites have been posting for years. So some people who claim to be architects and engineers apparently read those sites and bought into it, apparently without actually researching it any further or thinking much about it themselves; big deal. I won't go so far as to say I think the site is a total fraud -- after all, there are people with medical PhDs and licenses who believe all sorts of loony medical things, too -- but if you can find any technical paper on that site that reads like it was actually written by a structural engineer, please link directly to it rather than ask me to wade through the same ol' nonsense yet again. If I can debunk most of what I saw there just off the top of my head, without even looking stuff up on the debunking sites, then you can't expect me to be impressed by their (claimed) credentials, can you? (I didn't read everything there, but I presume if they had some strong stuff, they would give it some prominence, and everything I saw was junk like Rice's "Why the Towers Fell: Two Theories" nonsense.)

Simple challenge: If you can find anything resembling a scientific explanation for why the buildings couldn't have collapsed the way NIST says they did -- one that I can't debunk myself -- then I'll have to admit that the site is being unfairly ignored by people who are more capable than I of evaluating it. Where is it, please? And when one of those guys comes up with a peer-reviewed technical article, then you'll really have something. Otherwise, all you've got is an "appeal to (presumed) authority" fallacy (which appears to be a double fallacy).

As for joining their forum, when I was there last, they had a "true believers only" policy for joining their "organization" and non-members can't post in their forum. Their "public view" forum only had 2 "please join us" posts. Doesn't sound to me like they are really interested in any technical debates.

(Edit to add: You disingenuously left out the important part of my quote: "Now, I'm not a structural engineer, but I did work for 5 years as a structural draftsman in several engineering offices, so I do have some familiarity with the subject. But that's not particularly important since I'm not relying on my own expertise; I only claim that I can reasonably follow and understand what the experts say." When you post something that you think is scientific from that site, I'm going to be comparing it to what those experts have written.)

[Ezlivin]

327. Done that

On first blush the site seems to be as you said, but realize that this is a new group that is still getting organized; it provides a "public" face so that neophytes can quickly get up to speed on the theories concerning the collapse of the WTC without having to wade into overly technical discussions. The member-only forums have ongoing technical discussions, but nothing has been officially formulated or published yet. From what I've seen they are being exceedingly cautious until they have solidly researched and vetted data to present. Since many of these architects and engineers have active careers the last thing any of them wants to do is to hastily publish something that could reflect on themselves.

Have you seen the presentation of Gordon Ross on the collapses? Or have you read his paper on Momentum Transfer Analysis of the Collapse of the Upper Storeys of WTC1? If you have the time to watch the presentation and read through the paper, I believe you will find a sound, scientific discussion of the collapse mechanism.

I'm curious as to why you dismiss William Rice's paper. What did you find faulty in his discussion?

I've written about the fallacies of the peer review process and why it is not foolproof. I don't dispute its usefulness, but I do caution against accepting authority for authority's sake, particularly when the verification or review process is easily swayed by politics. I'd love to believe in science unsullied by political considerations but it doesn't exist (as exemplified by the actions of the Bush administration).

There are enough anomalies surrounding the events of 9/11 to warrant an independent, fully-funded investigation.

(I omitted the entire text of your comment only because of the limitations of the subject line.)

[William Seger]

328. Gordon Ross

Yes, I've read Ross's momentum transfer paper, and his hypothetical collapse sequence, and argued about them many times. I presume you've read Dr. Greening's rebuttal, at least, which is very good, and there are many others from qualified people, but Ross is another one I can pretty much debunk myself without a lot of help, since the rebuttals involve logic rather than math.

There are several glaring flaws in Ross's analysis covered in those rebuttals, but I found one myself that I haven't seen anyone else mention, but which I think is a pretty serious flaw: He uses the law of conservation of momentum to make a huge amount of energy "disappear" from the impact zone (imagining that it's been transferred to floors below by accelerating them as the columns compressed), and then claims that there wasn't enough energy left in the falling mass to sustain the collapse. But I had a physics professor who repeatedly made one important point about the conservation of momentum law: it only applies after the colliding bodies have regained equilibrium -- after all the compression and deformation and rebounding. Ross tries to use the law right in the middle of the collapse, which is really to say right in middle of the collisions, since the colliding bodies never really reached equilibrium until the whole thing was on the ground: Columns were still compressing and either breaking free and rebounding or deforming all the way down. Specifically, the reason it matters: Ross assumes that a strain wave propagated down the columns at 4500 feet per second, compressing the columns and accelerating a couple dozen floors attached to the columns downward during the time that the columns on the first collapse level were being pushed through their plastic limits and failing. Nowhere do I see him taking into account that the inertia of the floors attached to the columns would slow down that strain wave propagation and the resulting compression of columns below; he just tacitly assumes that a couple dozen levels of columns compressed 2% of their length and carried the floors with them during that time. I don't buy that.

Another problem many people have pointed out is that Ross assumes that the falling block hit squarely on the floor below, compressing all the columns uniformly through their elastic and plastic limits before failing. In reality, with the top block first tipping and then the columns at that level being bent and progressively failing horizontally, the initial collapse was too asymmetric and chaotic to allow that assumption. According to the NIST theory, the sagging floor on at least one level pulled the columns slowly inward on one side (which is seen on several videos). The only way those exterior columns could buckle inward would be if the floor was no longer acting as a diaphragm to distribute forces laterally. With the floor slab failed, the structural integrity of that entire level of the building was simply gone: Columns could fail by simple being pushed aside instead of being compressed through their plastic limits. When the whole thing started down, there was certainly a lot of damage to the floors and core beams at the same time that the columns were being hit. Without horizontal structural integrity it's just completely unrealistic the think the columns were absorbing their full theoretical load before failing. That's exactly why dailykoff does not see very many buckled columns: Most of them were simply pushed aside and broke at the joints before they reached their elastic limits.

But even without all that, Greening and others have shown that Ross "double-dipped" in one part of his calculation, using the same energy twice, which alone invalidates his result.

As for Ross's proposed collapse sequence (which he correlates to a supposed demolition plan), I find it to be contrived, illogical, and contradicted by the evidence. I don't really feel like going into the whole thing right now, but just one example: Ross proposes that the exterior columns were pulled in when the core columns were demolished is such a way as to displace the core in the other direction. (1) That doesn't explain why the columns were seen to be bending slowly over a period of about 20 minutes before the collapse. (2) If the core had been displaced to drag the columns in, we should have seen the whole top block shift: A shifting core would have at the same time pushed the columns on the other side outward and the side columns sideways, neither of which were observed until the collapse was definitely under way and the top block was tilting, and those actions are clearly the result of the tilting rotation. (3) Ross doesn't explain how moving the core columns would have only pulled the columns in at one level, without also pulling in the columns above that level. Anyway, since that part of his scenario just doesn't make a lick of sense, there really isn't much reason to look at the rest of it.

[Ezlivin]

329. Thanks

I appreciate your thoughtful answers.

Yes, I'm aware of Greening's rebuttal and of Ross's answers and rebuttals to Greening.

I suspect that we shall see a bit more of this back and forth between proponents of various theories until someone comes up with numbers to satisfy everyone (if that's possible). It's a damned shame that we don't have access to the steel removed from the collapse; with proper samples of that we could easily prove or disprove nearly any theory.

[AZCat]

330. Not necessarily.

One of the difficulties is that steel recovered from the site has possibly undergone changes during the collapse or during the time it spent in the pile of debris, and it is difficult in certain cases to tell when the changes occurred (i.e. prior to collapse, during collapse, or afterwards).

[dailykoff]

59. You got that right, petgoat!

"In effect the core was a giant vertical truss."

Well put!

:yourock:

[MervinFerd]

37. Nonsense, Mr. Goat. And tiresome, as usual.

"All the structural engineers in the world" may very well disagree about the detailed mechanism of the collapse. And the consensus opinion -should- develop with years of study.

But, these engineers have -always- been in complete agreement that -some- form of progressive collapse was responsible and that there is no plausible scenario that involves explosives.

And most completely certainly, no engineer has seen "conclusive proof" of explosives.

Now run along.

[petgoat]

41. There is no indication that "all the structural engineers in the world"

disagree on the detailed mechanism of the collapse, or that they even have an
opinion on the detailed mechanism of the collapse.

First we had the zipper theory, which had the perimeter columns buckling outward,
and there was no debate whatsoever.

Now we have the floor-sag theory, which has the perimeter columns buckling inward,
and there is no debate whatsoever.

Of course if anyone had bothered to examine the perimeter columns when they were
on the site we would have some evidence to examine, but the ASCE investigators
were excluded from Ground Zero.

The silence of the structural engineers may be interpreted as

"OK, whatever you say, Mr. Official Expert Man."

"I'm too busy to even think about this."

"It looks kind of hinky, but I'm no expert in the engineering of 1300 foot
buildings, and I can't see the blueprints, and I don't have time to do a
proper analysis, so I'll keep my mouth shut."

"I checked over the zipper theory throughly and I believed it 100%, but
after reading the NIST report I see that I was mistaken and now I
believe the NIST report 100%."

these engineers have -always- been in complete agreement that -some- form
of progressive collapse was responsible and that there is no plausible scenario
that involves explosives.

Do you have a link to some kind of statement from a professional society or
something? Do you have any references to any facts supporting thisopinion?

Why is there no plausible scenario involving explosives? What's so implausible
about blowing up a building so it falls down and goes boom? Is this an
engineering opinion or is it based on certain assumptions about security?

no engineer has seen "conclusive proof" of explosives.

The OP said proof of demolition, not explosives.

Now run along.

Maybe you better get you a star before you tell me to get off somebody else's
thread in a forum you don't own.

[Name removed]

80. Deleted message

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

[petgoat]

86. "there are disputes about details of the collapse"

Absolute hogwash.

There are no disputes. There is no debate. When the official story was
the zipper theory, NOT ONE CREDENTIALED PERSON CHALLENGED IT FOR THREE
YEARS!

This despite the fact that the zipper theory was patently absurd.

When NIST repudiated the zipper theory, NOT ONE PERSON WOULD DEFEND THE
PREVIOUS CONVENTIONAL DOGMA.

Please provide some evidence of dissent, debate, or controversy.

run along.

Still no star, Mr. Ferd?

[William Seger]

99. Wrong again

Is that a hobby with you?

> Absolute hogwash. There are no disputes. There is no debate.

Read Dr. Greening's (Gordon Ross' arch nemisis) paper criticizing the NIST report. You'll be enlightend to note that his conclusion is that NIST's computer model is "highly inaccuate" with respect to the tilt that preceeded the collapse, and offers an alternative analysis. (But almost needless to say, you won't care for what that analysis shows, either.)

http://911myths.com/NISTREPORT.pdf

> Please provide some evidence of dissent, debate, or controversy.

Done.

[petgoat]

104. One swallow does not a spring make, and if that's all the "controversy"

you've got, you've proved my point.

Dr. Greening's minor quibbles with, but general validation of, the official
analyses does not make a controversy.

[William Seger]

107. Wow

I proved your point by proving you wrong? Damn, you're a tough nut to crack, ain't ya. :banghead:

[petgoat]

122. You didn't prove me wrong. There has been no controversy.

Dr. Greening's quibbles do not rise to the level of controversy.

[MervinFerd]

112. O' Good Grief, Mr. Goat.

YOU were claiming changes in the "official story" as evidence the experts were wildly divided. NOW you want evidence of controversy?

Good Grief.

Perhaps the experts, who actually know something about the subject, don't think the "zipper theory" is absurd. Perhaps they consider it a reasonable approximation and the NIST study a refinement of that. Or, perhaps serious people knew that the exact mechanism were complex and withheld judgment until the matter was carefully studied.

Now, run along, Mr. Goat.

On edit: And I will get my star when the check from the NWO comes in.

[petgoat]

123. I was claiming no such thing.

YOU were claiming... the experts were wildly divided.

I wasn't. The experts are wildly groupthinking.

Perhaps the experts... don't think the "zipper theory" is absurd.

They should. It doesn't explain the collapse of the core.

I will get my star when the check from the NWO comes in.

I suspect your account is under review.

[William Seger]

27. Slight problem with your "analysis"

If you'll look very closely at your first picture with the compression failure, you'll note that the top and bottom of the column are still firmly attached to stuff. Under vertical overloading, compression failure is the only option if the top and bottom can't go anywhere. Now, if you'll look very closely at the columns in the WTC debris, you'll note that most of them are straight but have simply broken off where they were bolted to columns above and below. A little imagination about what was happening in the collapse of the towers -- no structural engineering degree required -- will help you figure out what happened and why.

Think about it before you reply.

[G Hawes]

32. "Conclusive evidence of premeditated murder"

Surely, since you claim to have "conclusive evidence of premeditated murder", (your bolding, not mine) you have done something more than hang around on conspiracist message boards posting the same old photographs that have long been within the public realm, right?

Surely, you have taken your "conclusive evidence" of "premeditated murder" to the appropriate authorities, right? Thanks to you, the bad guys will be taken off in shackles by morning and there is nothing that the evil msm can do to keep it from the enlightened among us, right? Kudos to you for breaking the conspiracy wide open. I can hardly wait to see the breaking news of your incredible feat online tomorrow. It is definitely time for this thread to be moved to LBN. Mods? Mods! Come on, now, dailykoff has just broken the entire conspiracy wide open with his use of a few five year old photographs that are "conclusive evidence" of "premeditated murder"!!!!!oneone11eleven!! Don't you think you should put this on the front page now?


Oh, wait...

[Anarcho-Socialist]

51. There's no way anyone can top this proof

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=125x56836

:D

[G Hawes]

58. Woo to the extreme.

I thought that was a joke at first, but then I read through the thread and it became apparent that it wasn't intended to be a joke at all, but it sure is in the result. Unbelievable.

Thanks for the heads up. I had no idea that there were so many woos here.

[MervinFerd]

81. Classic. What was needed, though...

was a bunch of firecrackers at the corners of the wires.

[petgoat]

182. Nobody said that was proof of anything. nt

[dailykoff]

84. Thanks, I was trying to keep it simple

for you and for anyone else who might happen to read this.

The point is that this is just one of many obvious smoking guns, and the more people are aware of the fact the sooner Congress will take action. Frankly every day wasted means a hundred or more lives lost in Iraq.

So how about helping us get the word out? :)

[greyl]

85. Sure, we'll help you get the evidence out. Show it to us. nt

[TheWraith]

49. That's not a logical conclusion.

"to the point where gravity overcame them, and then in an as-yet unexplained chain reaction, the rest of each building's members also failed, nearly simultaneously."

To anyone with engineering knowledge, it's pretty much obvious. It's called impact load. The towers were designed to hold up their own weight plus safety margin under static conditions. A certain number of the core supports were damaged or severed when the plane crashed into the building. That ate into the safety margin. When the fire reached 600 degrees fahrenheit, the remaining steel columns lost their load-bearing strength, and would have come apart, dropping the upper portion of the tower onto the uncompromised lower section.

The impact load of the upper portion of the tower crashing onto a lower floor was far greater than the static weight it was designed to hold up, causing the supports to buckle.

"The existing 9/11 photography shows clearly that this did not occur, because the columns that can be seen flying out of the buildings before and during the collapses, and can later be seen lying or standing in the debris, are clearly UNDEFORMED"

Load failure doesn't require that the columns be bent over at right angles or the like. The failures would happen first at the weakest point in the construction, which would be the joints between the columns. If you look at the photos, you'll see torn anchor plates and broken rivets all over the place. That's where they broke.

Lastly, not all structural columns had to be compromised in order for the building to collapse. This is particularly true for the outer columns, which did not bear the majority of the structure's weight--in fact, they bore relatively little. Note that you won't find long pieces of the internal supports, which is where the weight of the building went.

[petgoat]

56. "When the fire reached 600 degrees fahrenheit"

NIST has not one piece of core steel showing heating above 250 degrees C.

You are supposing something for which you have no evidence other than
the fact that the buildings came down. You are supposing that all the
columns were heated simultaneously and all failed simultaneously.

That's supposing an awful lot, isn't it?

Note that you won't find long pieces of the internal supports, which is
where the weight of the building went.

Right. And you should. Because a bird nest can not knock down a fence post,
no matter how hard it hits it.

[AZCat]

57. That's a pretty strange analogy.

And untrue, I might add. Have we forgotten our Newtonian mechanics?

[TheWraith]

78. Celsius and fahrenheit aren't the same thing.

NIST has not one piece of core steel showing heating above 250 degrees C.

Actually, that's a complete myth. Three columns showed evidence of having heated to above 250 C--which, by the way, is nearly 500 fahrenheit already.

You are supposing something for which you have no evidence other than
the fact that the buildings came down. You are supposing that all the
columns were heated simultaneously and all failed simultaneously.
That's supposing an awful lot, isn't it?

I'm not supposing anything of the kind. All that would have to be broken/compromised by the impact, and by the resultant fire, would be the safety margin plus 1, at which point no amount of effort by the surviving pillars would have kept the building in the air.

Right. And you should. Because a bird nest can not knock down a fence post,
no matter how hard it hits it.

That's a completely ridiculous comparison. A bird's nest doesn't weigh 200,000 pounds, as each tower of the WTC did. That you would even make such a comparison shows that you don't know virtually anything about the engineering involved. A better analogy would be if you built a support structure out of Lincoln logs, then dropped an anvil on it. The towers weren't built to withstand the gigajoules of kinetic energy resulting from their own upper sections landing on the lower floors.

[petgoat]

87. Nobody said they were.

Three columns showed evidence of having heated to above 250 C

3 perimeter column samples, that's correct. Note I said no core steel heated
above 250 degrees C.

All that would have to be broken/compromised...would be the safety margin plus 1

Isn't the usual safety margin a factor of 5?

Are you claiming 38 of the 47 core columns lost all strength? How many core columns
do you believe were broken by impact in the south tower? As I see it, the fuselage
missed the core entirely, and the port engine could only have taken out a few.

A bird's nest doesn't weigh 200,000 pounds

Neither does a fence post.

A better analogy would be if you built a support structure out of Lincoln logs,
then dropped an anvil on it.

Ah, so the top 30 stories weighed more than the bottom 80 stories? Try again.

[Bolo Boffin]

93. It's more like

The top 30 stories falling the length of a single story could overwhelm the joints of each floor below them all the way down.

[petgoat]

102. Your 30-story pile driver did not exist after the first couple of

seconds. Look at the pictures. Where did that dust come from
except from the complete disintegtration of the upper 30 stories?

Even had the 30 stories retained structural integrity for some
period of time, it would have been nibbled away gradually,
gradually losing mass. The disorganized debris would have
expended its energy in churning around, and the lower the
structure, the more robust its construction.

The pile driver model is like expecting that emptying a trash can
on it will pulverize a fire hydrant.

[Bolo Boffin]

108. Yes, it did. The upper floors are not disintergrating into dust.

They are falling into it. They are being obscured by it. They are not dissolving.

You are absolutely correct about the upper floors being "nibbled away gradually". However, you are absolutely incorrect that the "disorganized debris" would thereby lose mass. A girder has the same mass whether connected or not - and no appreciable energy would have been subtracted because of "churning around". The order for the day was DOWN, issued by gravity.

I will let the next available dog give your fire hydrant strawman the treatment it deserves.

[petgoat]

121. Nobody said the disorganized debris would lose mass.

Drop a ten pound book on my head and that would hurt.

Ten pounds of confetti wouldn't.

Disorganized debris loses kinetic energy, because it
expends energy in bouncing about rather than falling.

Hit a nail with a hammer and you sink it. Empty
your toolbox on it and you won't.

[AZCat]

126. Yes - you did (in post #102 of this thread).

In case you've forgotten, I've provided a quote:

petgoat Wed Dec-13-06 09:25 AM
Response to Reply #93
102. Your 30-story pile driver did not exist after the first couple of

seconds. Look at the pictures. Where did that dust come from
except from the complete disintegtration of the upper 30 stories?

Even had the 30 stories retained structural integrity for some
period of time, it would have been nibbled away gradually,
gradually losing mass. The disorganized debris would have
expended its energy in churning around, and the lower the
structure, the more robust its construction.

The pile driver model is like expecting that emptying a trash can
on it will pulverize a fire hydrant.

I have bolded your statement (for easy location).



Now perhaps will you stop butchering physics? Newton's rolling over in his grave.

[petgoat]

129. I was not butchering physics and I did not say the debris lost mass.

I said the putative piledriver lost mass. The 30 stories.

Though in fact, the tower-foorprint debris lost mass too, as the
concrete turned to dust and floated away.

[Name removed]

130. Deleted message

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

[petgoat]

133. The claim is made that the top thirty stories of the building

represented a piledriver pounding on the lower 80 stories.

As the pile driver disintegrates, pieces fall off. The pile driver
loses mass. The system does not lose mass, because the pieces are
still there, but the disorganized pieces are no longer part of the pile
driver.

The disorganized pieces do not have the authority of the piledriver
mass. It's the difference between dropping a three-pound brick
on your head and pouring three pounds of sand on your head.

I'm sorry if this is too complicated for you. Maybe you can get a
high school student to explain it to you.

[AZCat]

135. Aargh... You're not supposed to make me eat crow - bad for diet.

Mea culpa - I guess I should take my own advice about reading comprehension, huh?

I disagree with you, but now see that you did not commit the grievous error I thought you did (and managed to make an ass of myself in the meantime).

[petgoat]

137. I probably wasn't as clear as I could have been....

multitasking and all that.

[William Seger]

138. You're still wrong

Yes, you can discount a small part of the total mass as not participating in the "pile driver" effect. What you can't do is dismiss enough of it to stop the effect. Obviously, the steel wasn't pulverized at all, and a lot of the stuff that was pulverized -- concrete, drywall, office contents -- was trapped in between the steel decking of the floor slabs. (You also have no idea how much of the concrete, etc., was pulverized in the initial collapse rather than in the final collision with the ground.) The sand in your analogy is effectively in a steel box, not poured slowly as loose grains.

[petgoat]

141. The picture shows the concrete pulverized and ejected from

the building 800 feet above the ground.

Presumably whatever did that disrupted the steel structure
as well.

[Realityhack]

336. You are also missing another important factor

You make it seem like once the original 'block' is gone nothing is left overloading further floors.
Each floor destroyed in the decent adds additional falling mass.

It's not so much like dropping a brick vs. a handful of sand. Its more like dropping 200 bricks or 2000 chunks of gravel. Either way you are fucked.

[dailykoff]

186. That's a nice bedtime story, and I'm sure it looked cool on TV

but unfortunately it has nothing to do with reality. There are so many whoppers in these NOVA-induced pipedreams it's hard to know where to start, so let's just take the first hilarious paragraph:

"To anyone with engineering knowledge, it's pretty much obvious. It's called impact load. The towers were designed to hold up their own weight plus safety margin under static conditions. A certain number of the core supports were damaged or severed when the plane crashed into the building. That ate into the safety margin. When the fire reached 600 degrees fahrenheit, the remaining steel columns lost their load-bearing strength, and would have come apart, dropping the upper portion of the tower onto the uncompromised lower section."

I'm guessing that the idea here is that the impact from the crashes banged up the buildings so badly they couldn't recover, and when all that fuel started burning, well, down they went.

But this is quite ridiculous because the towers were designed as moment frames, meaning that they could absorb a huge amount of lateral force (wind loading) by deforming and then simply spring back, which is what they did after the crashes (which were well within the design load limits) -- spring back.

This means that the force from the crashes had no effect whatsoever immediately after the impacts were transferred through the frames to the ground.

[Athelwulf]

63. Question

Is it being argued that Bush was behind this?

[petgoat]

64. Personally I prefer to separate the political implications from

the scientific issues. Certainly it is argued that Bush was behind the demolition
of the towers, but I think it clouds the rational consideration of the case because
a discussion of the evidence becomes polluted by the subtexts of "Bush did it and I'm
by god going to find the smoking gun that proves it!" vs. "Not even Bush would ever
do that, and anybody who even thinks about it is cuckoo."

I couldn't consider the demolition evidence dispassionately until I supposed that
explosives might have been planted by al Qaeda opperatives who rented office space
in the towers and sneaked out after midnight to plant charges in the elevator shafts.
Viewing it that way made the operation imaginable.

And of course, if al Qaeda could do it, anybody could do it.

[greyl]

66. Your pairing of "subtexts" is ludicrous.

The second one doesn't relate to reality here at all. I've never seen anyone here express an attitude that people in our government/culture are too ethically sound to commit such a crime; that it is unthinkable, iow. They are saying "show me the evidence that's convinced so many believers".
Things go downhill from there, just like when evidence is demanded for homeopathy, astrology, and auras. The blame for the lack of evidence is shifted to the debunker, as a way to defend ones faith.

[petgoat]

67. The demand for evidence is disingenuous when you know

full well that the evidence has been suppressed and destroyed.

Of course, that suppression and destruction is itself evidence.
Also evidence is the poor quality of the official investigations,
as well as the popularity of absurd "debunking" theories such as
the piledriver theory of the destruction of the towers which is
clearly at odds with the fact of the tops of the towers
disintegrating in seconds.

Yes, the overstated claims of proof from the believers are wearisome
but I find it hard to believe anyone would spend his time in the
forum trying to rein them in if he didn't believe Bush didn't do it.

[greyl]

68. Atheists hear similar BS from believers in the R/T forum.

As I said above, the blame for lack of evidence is shifted to the debunkers so that the believer may retain their faith. Now, you're compounding that with begging the question and expanding the conspiracy.

Why do they call it faith? Lack of evidence.

[petgoat]

71. Lack of evidence >< provable destruction and suppression of evidence nt

[greyl]

73. Why do you believe the "destruction" is provable

if you don't have evidence to support that belief?

You are claiming:
1. There is no evidence
2. Evidence was suppressed
2. You have evidence

I think you have an intense desire to believe.

[petgoat]

74. Sorry, excess compression in my post.

What's provable is not destruction of the towers,
but destruction of evidence, and suppression of evidence.

[greyl]

75. evidence of what? nt

[petgoat]

77. evidence of what happened. nt

[greyl]

79. Don't you mean evidence of what you believe happened

as opposed to what the overwhelming amount of available evidence proves happened?

[petgoat]

88. What overwhelming evidence are you talking about? nt

[greyl]

89. Every component that forms the so called OCT.

All details that form the story which CTists claim to be a hoax.

[petgoat]

90. You are easily overwhelmed. nt

[greyl]

91. The evidence is so overwhelming that it's impenetrable by the CT's

"evidence".

If there were enough information on which to base a solid belief of Inside Job, why do CTists need to get a new investigation? (from Congress, fercrisake!)

[petgoat]

190. "why do CTists need to get a new investigation? "

Because the official investigations are full of holes.

[Bryan Sacks]

163. talk about ludicrous pairing!

conspiracy theory with astrology???

The first posits entirely human causation, occluded by complicit individuals aided by entrenched structures of power, and entirely empirically verifiable in ideal circumstances (which one can never expect, given their nature).

The second posits otherworldy causation (or at least influence), entirely beyond empirical confirmation.

I'm not defending it, but conpiracism has the same theoretical verifiability as an individual conspiracy theory - it's just that's conspiracism is clearly ridiculous on empirical grounds.

[Athelwulf]

70. So is the majority...

of people who believe this not like you, in that they don't separate political implications from the issue?

[MervinFerd]

83. Sinister Insinuation.

A major technique of Conspiracism is to -imply- something sinister without actually making an actual accusation:

"The towers were demolished by tons of explosives, but I'm not making any accusation"
"Larry Silverstein made money of 911 and was Ariel Sharon's buddy, but I'm not making any accusation"

See how it works?

[MervinFerd]

82. Answer: YES

The Conspiracists will -almost- always argue that they are "just asking questions", and have no theory.

That's because their theories are so ridiculous that if the stated them clearly, no one would listen to them.

Basically, this whole forum is about the "Secret Shadow Government" that runs all things in the world.

[Athelwulf]

94. I suppose so...

I am quite skeptical of conspiracy theories in general, and especially this particular one.

I wanted to know if people think Bush was behind it, because if they do, then I feel they're giving way too much credit to the guy. I mean seriously, planting explosives in two major towers in the heart of Manhattan, detonating them, and getting away with it requires brains. And this is Bush we're talking about here.

Recently, a member of the local peace group brought Loose Change to the meeting and declared that there was no doubt in his mind the towers were destroyed by something other than the planes. I thought to myself "Oh shit..." because I definitely don't want to associate myself with this, and this peace group is a progressive sanctuary of sorts in the middle of Oregon's Alabama. If all the members start believing this conspiracy theory, it might leave me intellectually homeless.

[MervinFerd]

95. It's a real problem.

The Truther Movement has nothing whatever to do with Progressive or Leftist or Democratic Party causes. In fact, the roots of the movement are in the Far Right. The original 911 conspiracy theory was a claim that hundreds of Israelis did not come to work in the Twin Towers on 911. The claims that Larry Silverstein made money off destruction of the towers is part of a larger theory that Israeli intelligence actually planned and executed 911. They just can't say that out loud on this forum because the mods will delete it.

The Controlled Demolition crowd isn't talking about a few charges to help the towers fall (which could have been planted by terrorists as easily as by the Gov't). The 'evidence' is of a vast amount of explosive on every floor of the towers. Such a project could only be completed by a "Secret Shadow Government"--presumably the same one feared by the militias of the Far Right.

The various No Plane theories--including the Pentagon missile theory-- are just beyond rational debate. One is truly baffled at how to address such nonsense.

How or why these fringe theories have gotten attached to the Left and found a following is a true mystery. But they continue to be a real problem.

There is a small group of us that bravely (or pedantically) try to keep some rationality around here. Sometimes we are so involved we don't pay attention to a person with legitimate questions.

There are a number of debunking sites around. I don't keep a list handy. But 911myths is good and Popular Mechanics posts the text of their debunking article. The James Randi Foundation forum (JREF) does merciless skewering of Truthers.

Anyway, Good Luck in Oregon. I presume you are in Eastern Oregon--the flat and dry part?

On Edit: Oh, and there are a bunch of debunks of Loose Change--search ScrewLooseChange, for example. That's a true and real Piece of Shit. They are grifters making lots of money selling lies and fear. Despicable.

[Athelwulf]

143. Thanks for the tips

And I am in eastern Oregon, but only just barely. I'm only a dozen miles from the Cascades, in the southern part of the state. Not too flat here, but it's still a "high desert."

[OmmmSweetOmmm]

96. Can anyone look this up? My son's gf's grandfather, an exNY cop said he saw

the WTC being built (it was his beat) and noticed that they were building in explosives.

[DoYouEverWonder]

97. There have been rumors

but I've seen nothing to substantiate that.

I do believe that after the 1993 bombing, major work was done in both towers and WTC 7 and I think that is when they modified the buildings to make it easier to use existing mechanical systems to take the buildings down.

[OmmmSweetOmmm]

98. What he witnessed, and he swears to it, was that it was during the construction.

Personally it makes sense to me that they did that, as from some sources that I've read, the buildings were only going to have a limited "shelf life" and easier to pre-rig it, then to rig it for demolition later on. That does not rule out that certain people didn't take advantage of it.

BTW...the grandfather believes that the official story is a lie and according to my son's girlfriend, has boxes upon boxes of research he's done.

[William Seger]

101. Well

You can be 100% sure that you won't be able to "look it up" with any reliable source. Constructing an office building with built-in explosives would be a totally insane thing to do. So, of course, they would have to completely cover up that detail. But, the fact that they covered it up so well proves it's true. Or something.

[petgoat]

103. Why would built in explosives have been totally insane?

I could argue that it was a necessary part of the design concept.

There was a danger that the building would be bent in an extreme hurricane,
and thus risk toppling. And if it was bent but didn't topple, how would you
repair it? How would you demolish it?

Since in an extreme hurricane the building would be evacuated anyway,
an emergency demolition to bring the building straight down would not be
out of the question.

Of course, the explosives would have to remain a secret. Who wants to work
on the 90th floor of a building with built-in bombs?

You guys are very quick to label insane, stuff you've never even considered.

[William Seger]

106. Finally...

> I could argue that it was a necessary part of the design concept...
You guys are very quick to label insane, stuff you've never even considered.

Finally, something we can agree on.

[MervinFerd]

109. Well, no. I hadn't considered this one. Considering. ...considering.. ....

It's insane.

[LARED]

117. Bent like this?

[greyl]

113. So, he's a part of the cover-up!

What are you waiting for?

[MervinFerd]

115. Yep. Time to break this baby WIDE open.

Ya got -one- eyewitness. There -must- be hundreds of others. A construction site is a -very- public place.

Go for it.

You could go down in HISTORY! Book Deals! Interviews on CNN! The Speaking Circuit! FAME AND FORTUNE!

GO FOR IT!

[petgoat]

120. "A construction site is a -very- public place."

I guess you missed ChristopherA's allegations that the
workers were sent away when the crews poured the explosives
around the columns.

[MervinFerd]

110. Just so we know what's been proved conclusively: Did -each beam- have...

it's own explosive charge?

On -all- 110 floors?

OK.

So, the hypothesis actually proved is this:

The Secret Shadow Government secretly worked in the shadows and installed many thousands of explosive charges inside the bowels of the building--two on each girder--, while the building was occupied. And, the charges are connected by a sophisticated wiring system so that they can be detonated in precise order and none of the charges were detonated or destroyed by the fires.

And nobody in the building noticed any of this.

Is this the hypothesis proved conclusively?? Just trying to be clear here.

[MervinFerd]

114. Still Waiting.

Not holding my breath, though.

[MervinFerd]

116. Waiting.

Hmmmm.

[MervinFerd]

118. Waiting. WHAT ARE YOU ACTUALLY SAYING?

It's a really simple question.

[MervinFerd]

119. Waiting. Nobody is going to answer, are they?

[mirandapriestly]

124. It's not the question it's the questioner

[MervinFerd]

125. OK. Fine. But, WHAT IS THE ANSWER TO THE QUESTION?

What hypothesis that was so conclusively proved?

Just answer the question.

[greyl]

127. Garbage.

"Things go downhill from there, just like when evidence is demanded for homeopathy, astrology, and auras. The blame for the lack of evidence is shifted to the debunker, as a way to defend ones faith."

[AZCat]

128. Whatever excuse you make doesn't change the question.

Nor does it provide an answer (at least the one he's looking for).

[mirandapriestly]

131. I don't read any of your posts, so I don't know what the question is

I just wanted to shut him up.

[MervinFerd]

139. Well, obviously you read -some- of my posts.

The question is:

What is the thing that is "conclusively proved" by the evidence in the OP?

I just want this stated in a clear manner.

It's really very simple.

[petgoat]

134. Each beam on all 110 floors? I don't think I saw anyone claim that.

A common tactic of self-styled "debunkers" on this board is
to invent imaginary impediments to the hypothesis they are
attacking.

The Secret Shadow Government secretly worked in the shadows
and installed many thousands of explosive charges inside the bowels
of the building--two on each girder--, while the building was occupied.

According to Dr. Romero, a few charges in key places could have done the
job. High rise office towers are thinly populated after midnight.


the charges are connected by a sophisticated wiring system
so that they can be detonated in precise order

Radio controlled detonators set off by computer-generated pulse
codes would allow the order and timing of detonation to be
reprogrammed quickly and easily in response to actual conditions.

nobody in the building noticed any of this.

When's the last time you inspected an elevator shaft?

[MervinFerd]

136. WRONG. That's --NOT-- the claim.

Nope. That's NOT what's being claimed here.

"A few charges in key places" is (remotely) plausible. But that's a --few-- charges, and a --few-- beams affected. The rest falls as in the standard scenario. Hence, --NEARLY ALL-- of the beams will look like exactly the same as in a gravity collapse. The probability of finding --even one-- beam hit by explosives is remote.

Now, run along, Mr. Goat.

[dailykoff]

148. Why don't you just read the thread title?

The "hypothesis" is clearly stated there.

[MervinFerd]

151. Did EACH BEAM have its own explosive charge?

Is that what is "Conclusively Proved"?

I can't tell that from the title.

I am "Just asking questions".

Somehow, I never get answers, even to the simple ones.

[dailykoff]

152. Okay. The answer is no, that is not what the photography proves.

The photography proves that the buildings were demolished, i.e., that their destruction was deliberately engineered.

You're asking how it was done. I think it's fair to say that we would all like answers to that question, but I'm not making any claims about it here.

[MervinFerd]

168. You can't prove one without proving the other.

If the beams were not knocked loose with explosives, then they would be knocked loose by the collapsing building.

You have to define what you mean by "demolition".

[mirandapriestly]

132. footage shows early explosions

http://www.youtube.com/watch?v=thOGlcatpDA

at about 4:36, right side of face of building; unmistakable that there were explosions, so why is there even an argument?

[MervinFerd]

140. Why were there "explosions" well BEFORE the building fell?

Practice?

[mirandapriestly]

142. Weakening the structure for demolition, obviously.eom

[dailykoff]

147. Thanks MP

There's a LOT of photography out there that makes the point more clearly than the handful of photos in this thread. Thanks for finding some!

[rman]

181. There's a lot of evidence out there that makes the point more clearly than your OP.

[dailykoff]

183. No kidding. So how about digging it up and posting it

before everybody scares themselves into a terrorgasm?

[rman]

172. Deformed columns right here:

I'm in the MIHOP camp but i don't think you have presented a very strong case.

[dailykoff]

173. Wrongsky.

This defenselink.mil pic has already been analyzed at length in the following replies to post #3 above, where it was originally posted:

#4: http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=127969
#145: http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=128843
#154: http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=128950

Allow me to restate a few of the salient points here:

a) the columns, not the beams, held up the towers;
b) the WTC core and perimeter columns both had box cross sections;
c) the noticeably twisted pieces in the pic are I-beams, and the columns are mostly rifle-straight;
d) the large curving perimeter wall section is bent, not buckled, meaning that it was damaged by falling, not by compression;
e) it's helpful to know what you're looking at before opening your yap, and that goes for Uncle Noam, too.

:)

[rman]

174. wtf has "Uncle Noam" got to do with this?

[dailykoff]

175. He would also do well not to palaver

on subjects he knows nothing about.

[rman]

180. Doesn't anyone?

Why bring up "Uncle Noam"?

[William Seger]

176. "it's helpful to know what you're looking at before opening your yap"

Un-fucking-believable.

You start a thread claiming to have "conclusive evidence of premeditated murder", which turns out to be based 100% on your own ignorance. You have:

- ignored the fact that FEMA found that some perimeter columns and about half the core columns were buckled

- posted a picture of a buckled column that could not happen to a WTC column, because of the end conditions

- looked at a few pictures and claimed not to see any buckling, then demonstrated that you have no idea what buckling really is, much less what it looks like

- demonstrated a complete lack of ability to understand buckling even when it's repeatedly explained to you

- dismissed a clear picture of a buckled perimeter column section as being "bent, not buckled"

- demonstrated a complete lack of understanding why specific design details in the WTC make a difference in buckling

- still can't explain why so many columns weren't buckled, even though the average 5th grader could probably figure it out.

Then you have the unmitigated gall to say "it's helpful to know what you're looking at before opening your yap."

Un-fucking-believable. You are one very special "truth seeker," dailykoff.

[dailykoff]

177. Um, aren't you the guy who thinks highrises are built out of hinged columns?

:rofl:

[William Seger]

178. Ya know what I really love about you dailykoff...

... even after you've been made to look completely foolish, you just keep posting and bumping the thread to top of the forum, just in case anybody missed it.

[dailykoff]

179. Wrong again, and I'm sorry to see you stooping even lower

than making farcical claims about the tower construction.

If you'll notice, this and every other subthread has been started by someone else, not me, and every reply I've made has been to answer a question or refute some idiotic claim. Thanks incidentally to petgoat and everyone else for doing a much better job of it than I have.

As a matter of fact I've made a point of NOT bumping this thread, and commenting in others instead, though for some reason those threads keep getting bumped down. Go figure.

[dailykoff]

184. A few more pics that make the point

from recent threads, the point being that the photography taken before, during, and after the collapses consistently shows an absence of buckled columns, indicating an absence of compression (gravity induced) load failure:

1. Construction photo showing robust diagonal core bracing:



2. Collapse photos showing undeformed columns and column sections being ejected from the towers:





3. Debris photos showing unbuckled core and perimeter columns:






Considering that every picture I've seen of the collapses and debris demonstrate the point that they were not caused by gravity, I think it's safe to say there's something to it.

p.s. happy holidays!

[Bolo Boffin]

185. Your robust diagonal bracing is scaffolding for the cranes.

But do not worry your beautiful mind with the facts.

Nice to see you recognize the pictures of the base columns as pictures of the WTC towers now.

[dailykoff]

187. Um, the cranes are on top, not inside the constructed core.

Are you going to start talking about C4-coated rebar?

[Bolo Boffin]

188. Ha, ha!

Have yourself a merry little Christmas.

[vincent_vega_lives]

195. "C4-coated rebar?"

No that's Christopheria's job (If that was his name?)

And I think what bolo is laughing at is that you are mistaken about the cranes.

[dailykoff]

203. A couple more classics from the archives:

(A) Two collapse photos showing undeformed columns being blown out:





(B) A large satellite debris photo showing an abundance of undeformed columns and not a single buckled one (get out your reading glasses OCTers):

?click

[spooked911]

189. The towers were indeed demolished but your argument is flawed

1) those pieces coming out in the first two pics are aluminum cladding, not structural columns
2) we aren't seeing a representative view of the strcutral columsn to make a guess

But the towers simply came down far too fast for any progressive failure.

[William Seger]

191. So is yours

Dailykoff got it wrong because he incorrectly thought that all buckled columns should look like his top picture, so he still isn't able to identify the WTC columns that are buckled. Also, he still doesn't seem to undertand that columns wouldn't have buckled if the structure holding their top ends from moving laterally was destroyed before they could buckle; they would simply be pushed to the side.

And you are wrong in claiming "the towers simply came down far too fast for any progressive failure."

http://911myths.com/WTCREPORT.pdf

If you disagree, please present your calculations. (Judy Wood's "billiard ball" calculations are idiotic, and even I can explain why if that's really necessary.)

[dailykoff]

192. Ah, more wisdom from hinged-column man.

Please find the hinges in these columns:

:rofl:

[William Seger]

194. Aw, jeez, you're having another hysterical fit

C'mon, dude, pull yourself together and at least try to think about it. Yes, those angles sticking out are the joist seats. As you should have learned from the web page I shamed you into looking up, the buckling shown in your top photo formed an S curve because the ends were "clamped," which is simply a relative term: The ends were held vertical rigidly enough that the column bent like that with less force than it would take to rotate the ends away from vertical. If the ends can rotate before the column can buckle like that, then it's considered a "pinned" connection, and the column will bend in only one direction (the weakest).

Now, simple question: Do you honestly believe that those 14" square columns would buckle like your top photo before those joist seats either bent or broke free? Please answer that question directly, yes or no.

I'll even give you a hint, in the hope that it might trigger a synapse or two: The proof that you're wrong is that most of the perimeter columns didn't buckle -- they broke free without bending -- but the ones that did buckle didn't bend in an S curve like your photo. They buckled like the photo that Taxloss posted, just as common sense would predict. Duh.

[dailykoff]

204. You are very very confused.

A pinned condition would only exist if the column-to-column connections allowed for rotation. They clearly do not. Sorry.

[dailykoff]

205. Well then, it looks like we've cleared up one more OCT lunacy.

The perimeter column connections were most certainly not pinned and compression failure would have manifested itself as buckling.

That it did not leads once again to the inescapable conclusion that gravity did not cause the buildings to collapse.

[William Seger]

206. You forgot your "special" smiley

You definitely needed one for that post:

> The perimeter column connections were most certainly not pinned and compression failure would have manifested itself as buckling.

The first part of the statement is incorrect -- they were relatively pinned in one direction which would be the direction they would fail in because that's the failure mode that requires the least stress -- and the second part of the statement is a non sequitur, "compression failure would have manifested itself as buckling." Compression failure in a slender columns will always manifest itself as buckling, because that happens before the ultimate strength of the material is reached, whether it's "clamped" or pinned. They're just different failure modes, which can be distinguished by their appearance: A pinned column will bend in a (roughly) sine curve like Taxloss' photo, while a clamped column will bend in an "S" curve like your top photo.

You're not really holding up your side of this "debate" ol' buddy: I've repeatedly told you exactly where you're wrong in both your facts and your logic, and you just keep ignoring what I'm saying and just repeating your incorrect assertions. Simply incorporating the same terms I'm using into your assertions, with no apparent understanding of what the terms mean, isn't "debating" the issue.

[DoYouEverWonder]

207. Please show us

a sample of this mythical peice of perimeter columns that you speak of, that was recovered from one of the Towers.

[William Seger]

209. Taxloss' photo

That's a buckled section of perimeter columns behind the policeman.

Anyway, did you look at the video I posted for you? There simply isn't any doubt about the perimeter columns buckling to start the collapse.

[DoYouEverWonder]

214. The section in the picture mark 150 & 9

does not show signs of being subject to fire.

See how it is located in the pile, it may have bent that way upon impact? Besides we don't know where in the building this piece comes from. Did anyone ever map the site and keep track where the important stuff was located? It would have been nice to have that data.

There is evidence of fire on the pieces sticking out above it, but those pieces are still very straight.

[William Seger]

217. Again, buckling isn't "caused" by fire

Buckling is simply bending caused by over-stressing a "slender" element along its axis. The slightest bit of asymmetry in either the shape of the column or the applied forces causes a column to flex to one side instead of compressing uniformly. That slight bend produces a "bending moment" with respect to force and the centerline of the column. As soon as the column starts to bend a little, that bending moment increases rapidly, and so does the further bending, because the the axis of loading gets more and more "eccentric" with respect to the centerline of the column.

The only part that fire plays is that it weakens steel to the point that it will buckle with less stress. For the core columns that you asked about earlier, even if the core columns only reached 250^oC from air temperatures, not from direct flame, that would have decreased their ultimate strength by about 20%, which would have decreased their resistance to buckling even more than 20%.

(Edit: Forgot to say: It sometimes isn't easy to tell buckling from other types of bending, but those particular columns are almost certainly buckled because (1) they're bent in the approximate shape of a sine curve with the maximum bend at the center, and (2) all three columns are bent in approximately the same way. Those two things would be improbable in the chaos of the grinding debris.)

[dailykoff]

225. Buckling is definitely NOT "simply bending."

Bending is deformation caused by force applied perpendicularly to the axis of a beam or column, and buckling is caused by force applied axially.

I pulled you out of this lake once before but I'm always happy to rescue unwitting travelers. :)

[dailykoff]

220. You mean the head injury smiley?

Maybe you should do a little less of that this year. :) As I've explained, a pinned condition would only exist if it was possible for the columns to rotate in one or more directions, and it clearly was not. See below:

[William Seger]

223. Wow, a tiny breakthrough !

> As I've explained, ...

Uh huh, that's sorta like what happened. :eyes:

> ... a pinned condition would only exist if it was possible for the columns to rotate in one or more directions, ...

Ah, some progress at last! A crack in the brick wall!

> ... and it clearly was not.

Oh really? "Clearly?" OK, go back up and look at that photo that I claim is a buckled section of perimeter columns and answer this question: Where are the joist seats on the spandrel plates that you claim would hold the column from rotating outward?

And, I'll ask this one yet again, just for fun: Do you or do you not think that the 14" square perimeter columns would buckle like your top photo before those joist seats would bend or break off?

[dailykoff]

224. Yes, your progress is encouraging.

I wouldn't get your hopes up for a full recovery but you never know. :)

About those joist seats: your persistent delusion that they somehow translate into hinged column connections tells me that your road is going to be a long one.

[William Seger]

226. Your grade on this quiz is a 0

I'm afraid your final grade is an "Incomplete" which means you will need to repeat Buckling 101 next semester. Good thing engineering isn't your major.

[dailykoff]

227. Let's go over the correct anwers together:

You claimed that column buckling such as that seen in the original OP photo would not have occurred in the WTC perimeter columns because the column connections were pinned rather than rigid.

However, a glance at the construction method shows that this is nonsense because (a) the column-to-column connections did not occur at the floors (they occurred between floors) and (b) they only occurred every three floors, making two of three columns per floor continuous, connectionless shafts. Both these conditions are clearly shown below:



The column connections were therefore rigid, and buckling -- had it occurred -- would have left tens of thousands of perimeter and core columns (there were 62,920 altogether) looking like this:



That there are no such thousands of buckled column demonstrates that the buildings did not collapse as a result of load failure which means (among other things) that the government is lying.

[William Seger]

228. Sheesh, you were doing better when you didn't answer

> However, a glance at the construction method shows that this is nonsense because (a) the column-to-column connections did not occur at the floors (they occurred between floors) and (b) they only occurred every three floors, making two of three columns per floor continuous, connectionless shafts.

Wrong answer. Those column-to-column connections have nothing to do with buckling, except that we know most of those connections failed before the columns could buckle at those levels. The points of concern for buckling are those at which they are restrained from moving laterally. For that purpose, even if those column-to-column connections had been stronger than the columns -- of even if the columns had been continuous steel all the way up! -- buckling would still occur between the points of lateral constraint -- at the joist seats -- provided that those connections were strong enough to hold while the column buckled. And again, where buckling did occur (i.e. in those few cases where the columns buckled before those joist seats could be ripped right off the spandrel plates), the type of buckling would depend on the type of restraint. Just as you already admitted, a pinned connection is one where the column is restrained from moving laterally but the column can rotate, which is the case with those relatively thin angles of the joist seats: they would allow the columns to rotate perpendicular to the wall. Now, if you could somehow stress only one column out of the group, then the stiffness of the spandrel plates would also come into play for preventing rotation -- and it would take a precise calculation to determine if the force required to twist the plate was less than or greater than the force to buckle the column -- but that's not what happened: all of the columns were subjected to approximately the same stress at the same time.

This is not complicated, and we're right back where we started: There was nothing to "clamp" the ends of the columns vertically strong enough to produce the type of buckling that's shown in that picture. Your assumptions are simply false.

[dailykoff]

229. Have you noticed that no other OCTers back you on this?

Including your not-a-structural-engineer pal who put this lunatic idea in your head?

Maybe they're trying to tell you something. :eyes:

p.s. the joist seats had nothing to do with the perimeter column connections.

[Bolo Boffin]

230. Hey, you talking about me?

Cuz when you CTers say OCTers, I think you mean me, although I'm not pushing any theories here. Just the facts.

But let it be known: I like everything William Seger is saying. If I've said anything that contradicts what he's saying, I bow to his superior knowledge.

Seger is AOK in my book! I back him!

:headbang: :yourock: :patriot:

[dailykoff]

231. I was hoping to elevate the conversation

but I see the opposite has occurred. :)

[Bolo Boffin]

232. No, you were hoping to distract the conversation from the corner Seger's got you in

Nice try. Get back to the point. I'm enjoying watching Seger at work.

[dailykoff]

233. As I was saying. . . . (n/t)

[William Seger]

234. Have you noticed you have no idea what you're talking about?

I've been talking about exactly the same thing since my first post in this thread: There's a reason that you shouldn't expect to see WTC tower columns buckled like your photo, and that reason is the lateral restraint conditions. No "not-a-structural-engineer pal put this lunatic idea in {my} head"; it came from having a little familiarity with the subject, after being a structural draftsman for 5 years. LARED (and no doubt many others with above average intelligence) simply understood what I was getting at very quickly, and as I predicted then, you likely never will, even though you found your own source with a reasonably good description of buckling. Here's another, by the way:
http://en.wikipedia.org/wiki/Buckling
(Notice about half way down, there is a model showing the failure modes for the four different restraint conditions that the "Euler formula" considers. Maybe that picture is trying to tell you something :eyes:)

> p.s. the joist seats had nothing to do with the perimeter column connections.

I wonder: Have you considered the possibility that you may be the last person on this thread who doesn't yet understand that the buckling of a column will depend on where and how it's restrained laterally? The joist seats in one direction and the spandrel plate in the other are the only things that could possibly affect how a perimeter column would buckle.

[dailykoff]

235. I've noticed that you're easily taken in

by propagandists. I imagine you think there's some significance to the joist seats beyond their rather modest structural roles because Eagar and later FEMA and the NIST hinted darkly that the "truss clips" were the Achilles heel that brought the towers down.

They were not. They simply look as though they could be in photos such as the one below, and some clever propagandist decided to hang his hat on them.

In fact the joist seats were NOT the only way the floors were attached to the spandrels or even the primary attachment; they simply held the joists in place. The floor plates were then attached directly to the spandrels and the joists were attached to the floor plates by means of several kinds of welded connection.



p.s. there were also beams in the WTC floor assemblies whose numbers have been deliberately and dishonestly obscured by FEMA, the NIST and other propagandists but that is a story for another day.

[AZCat]

236. "Deliberately and dishonestly obscured"?

Of course you run off before presenting any evidence (of which I doubt there is any) of such a ludicrous claim - I would too if I was incautious enough to do the same.

It's alarming how easy it is to spread libel such as this from within the cloak of anonymity.

[dailykoff]

237. That's what I said.

The NIST acknowledges that a number of floors in each tower were "beam framed" but literally obscures the presence of joist girders and other beams by plastering the few sections of original framing plans that appear in its reports with ridiculously gigantic labels.

[Name removed]

238. Deleted message

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

[dailykoff]

239. Why don't you read the report before popping your cork?

Or reread it if you want to pretend you already have. I went through the whole damn thing last summer and I think you'll be surprised at what's actually in it, or not, as is frequently the case.

[Name removed]

240. Deleted message

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

[Name removed]

242. Deleted message

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

[AZCat]

244. Your lack of experience is showing (rather badly).

Why don't you do yourself a favor and talk to someone who has actually worked in contruction before making such ludicrous claims. Maybe you might learn something in the bargain (although that might be too much to ask).

[dailykoff]

245. You have yet to make a point. Keep trying. (n/t)

[AZCat]

246. I don't have to.

Your (apparently limitless) capacity for undermining your own arguments is powerful enough.

You don't know what you are talking about, and that should be apparent to anyone who actually does.

[William Seger]

241. Amazing. Unbelievably bad to even worse

Utter bullshit. The joists were the only things holding the perimeter columns from buckling outward, and the joist seats were what connected the joists to the spandrels. There were no beams connecting the perimeter columns to the core except on the mechanical floors, which were just between the 41st-42nd and 75-76th floors. Holding up the joists and being the only restraint in the direction perpendicular to the wall is certainly not what I would consider "rather modest structural roles."

What we've determined in this thread is that you have extremely little knowledge about structures and extremely limited capacity to learn more, and even worse, you have extremely little mechanical aptitude for understanding what extremely little you do know and have been able to learn since starting this thread. Yet you still think you're qualified to claim to have found "conclusive evidence of premeditated murder" based on absolutely nothing but your mistaken notions about buckling? I find it difficult to believe that you are still trying to assert that. It seems to me that you just can't let it go now, even though I'm sure some of this must be finally sinking in. What a sad joke.

[dailykoff]

243. I see you haven't read the NIST reports either.

As I recall the floorplate-to-spandrel weldments are mentioned in one of them.

[DoYouEverWonder]

208. Notice how the perimeter columns are staggered?

How could a whole floor blow out along one side, like you see at the start of the WTC collapses, if the columns were staggered?

[dailykoff]

193. Yes, there's ample evidence that the towers were demolished

and no evidence to suggest that they weren't. And when the construction documents emerge, it will also be evident that the NIST has grossly misrepresented the design and construction of the towers.

The problem is convincing the American public in a way that leaves no doubt in their minds. If DU is any indication, many who suspect that the WTC was rigged to blow also believe that there's not enough remaining evidence to be certain of it, i.e., that because the debris wasn't properly cataloged and analyzed, it's impossible to "prove" that the towers were demolished.

This is not the case, and the fact that they collapsed to the ground at all, at any speed, is itself ample evidence of demolition, but there doesn't seem to be a way to explain it in a way that's convincing.

Thus the buckled column proof: if the columns didn't buckle, then gravity didn't cause them to fail, and something else did. This can be easily demonstrated using existing photography -- there's simply no evidence I've seen of any core column buckling, and precious little of any perimeter column buckling.

p.s. I think your objections are legit in view of the limited number of photos here, but there are many more out there that show the same thing. Specifically:

(1) I don't think the column-shaped elements in the first two photos are pieces of cladding, but if you don't like those pics, look at other clearer ones, for example these two showing entire sections of columns being blown off:





(2) Yes, this is only a handful of photos, but there are many others that make the point more clearly, and the fact is that I have yet to see even one plausible photograph of a buckled core column -- and the progressive collapse theory requires most or all of them to have buckled.

[vincent_vega_lives]

197. Nope, not at all

Buckling only happened at the point of initiation...and relatively slowly. After that the progressive collapse happened so rapidly that the outer columns were torn free rather than buckled.

And yes I think your term "blown off" is a good one in describing progressive collapse, but your instance that only explosives could produce this effect stems from a consistent misunderstanding of energy transference.

Explosives are just massive amounts of energy stored chemically. The potential energy of the buildings released as KINETIC energy is NO DIFFERENT. Explosives release their energy in 360 degrees (even shaped charges direct only 2/3 of their energy in a single direction) and flame is a byproduct of the chemical reaction.

Kinetic energy involves no flame and has ALL its energy released in a single direction (direction of gravity in this case) but is NO LESS massive due to the MASS of the building above the collapse point.

I realize this is very hard to grasp for some people as it seldom manifests itself in every day life.

[dailykoff]

198. Exactly what "instance that only explosives

could produce this effect" are you talking about, apart from the one in your addled brain?

[vincent_vega_lives]

199. Oh Christ!

Hows this one for a start?

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=130562

Forgive me for not plunging into the archives. Every other "demolition expert" here has spouted it at one time or another.

[dailykoff]

200. The word "explosives" does not appear in that post.

But thanks for answering my question.

:rofl:

[vincent_vega_lives]

201. Oh REALLY?

then :wtf: are you referring to in this post? Physic demolition? You might want to reconsider that :rofl: gif.


The problem is convincing the American public in a way that leaves no doubt in their minds. If DU is any indication, many who suspect that the WTC was rigged to blow also believe that there's not enough remaining evidence to be certain of it, i.e., that because the debris wasn't properly cataloged and analyzed, it's impossible to "prove" that the towers were demolished.

This is not the case, and the fact that they collapsed to the ground at all, at any speed, is itself ample evidence of demolition, but there doesn't seem to be a way to explain it in a way that's convincing.

Thus the buckled column proof: if the columns didn't buckle, then gravity didn't cause them to fail, and something else did. This can be easily demonstrated using existing photography -- there's simply no evidence I've seen of any core column buckling, and precious little of any perimeter column buckling.

p.s. I think your objections are legit in view of the limited number of photos here, but there are many more out there that show the same thing. Specifically:

(1) I don't think the column-shaped elements in the first two photos are pieces of cladding, but if you don't like those pics, look at other clearer ones, for example these two showing entire sections of columns being blown off:

[dailykoff]

202. Really. (n/t)

[DoYouEverWonder]

212. Examples?

I'd love to see what you're talking about?

Looks like you didn't finish your post?

[DoYouEverWonder]

210. Notice the straight edge

along the bottom edge of the large piece that's coming down? That is the bottom edge of a mechanical floor. Since this is apparently one of the first pieces to come down, I think we have fairly solid evidence that a mechanical floor failed first.

PS: Just a side note - The guy who took that picture died in the collapse.

[Bolo Boffin]

211. Along the side of the piece, you mean?

The straight edge is along the side of the piece as it stood in the building. Notice the alignment of the perimeter columns.

I think we have fairly solid evidence that you don't know what you're talking about.

[DoYouEverWonder]

213. The bottom edge

of the big piece of perimeter wall that is coming down, ahead of most of the other stuff.

It's straight.

What about the alignment of the perimeter columns? They're staggered, not straight. Correct?

[Bolo Boffin]

216. I don't mean to misunderstand you. Let's be clear.

In this picture, which side are you referring to as the bottom edge:



Because A doesn't look all that straight, and B is quite straight, but also clearly the side of the piece as the lines of the joined perimeter columns show.

So which is it, A or B?

[DoYouEverWonder]

219. Yes I am referring to Side A

The only part that isn't straight are the two piece of aluminum cladding that are sticking out that managed to stay attached. It appears the those two pieces tore away from the steel they were attached to. Since they are each 7 pieces apart, there may have been some additional reinforcement of the cladding every 7 columns.

If you notice in the image here that isn't cropped -



there is another section of columns coming down a little bit behind and to the right, that's also cut straight across the bottom.

[dailykoff]

221. That IS odd.

Do you think it indicates some kind of thermite-type slicing?

[DoYouEverWonder]

222. No, I don't

What these images indicate is how the building was split apart and where the collapse began.

In most floors in the Towers, the prefabricated sections of the perimeter wall was staggered in order to avoid having a continuous seam around the building.



However on the mechanical floors only, the prefabricated sections are all the same level. This created a weakness in the building that the planners were aware of and were able to exploit.



Also, this would indicate that the mechanical floors were a major factor at the start of the collapse.

By Arthur Scheuerman Battalion Chief FDNY Retired,

<snip>

The fact that the collapse began, apparently simultaneously, around the entire upper floor outer ring and possibly the inner core of Tower 1 rather suggests an explosion or rapid combustion of gasses such as carbon monoxide or other flammable vapor residue from the jet fuel, over-pressuring the area. "A room or area requires only 25 percent of its space to contain the explosive mixture for the entire area to explode."(Dunn, WNYF p9) This may have been another reason the fire temperatures in general not being any greater than an average fire- incomplete combustion due to lack of oxygen in the main body of fire. "The observed fire behavior points to temperatures in the building not being particularly severe — say no more than about 600 to 700 Deg. C.

http://www.ericdarton.net/afterwords/fireandair.html

I think Mr. Scheuerman is onto something here, but I think that what happened was deliberate and not accidental. There were natural gas lines all around and through the WTC complex. There were reports of people smelling natural gas in at least two different locations near the Towers before the first plane hit. That's how come the Naudet Brothers happened to be outside filming around the WTC that morning and both of them were able to get such good shots of the first plane going in.

I disagree with Scheuerman about the gas collecting near the top of the building since so many windows had been broken out either by the crash or by the people who were looking for a way to escape the buildings. However, the mechanical floors did not have windows. If gas accumulated on these floors, which were stronger then normal floors, the resulting explosion would start the chain reaction that brought the building.


I don't rule out the use of thermite on the upper floors, but if it was used, it was only in the crucial corners that also needed to be knocked out in order to cause a total collapse, rather then a partial collapse.

[William Seger]

302. Is that from the south tower?

Given the damage to the other end of that section of perimeter walls, it looks like it could have come from just below where the collapse started in this video: http://video.google.com/videoplay?docid=-5405555553528290546&q=wtc+south+tower

How does your theory work if the collapse started a couple floors above the mechanical floor?

[mirandapriestly]

301. interesting, every seventh one...

I'm going to look through a book I have of ground zero photos and see if there is more of that: good find DYEW.

[DoYouEverWonder]

215. Dupe post

n/t

[William Seger]

218. Don't thnk so

Yes, I agree that was a section that terminated at a mechanical floor, but I disagree with your conclusion that it implies the mechanical floor failed first. From the damage at the other end, it appears that the failure started at least a couple floors above that. And, there appears to be an even more damaged section in the lower right, which fell even before that piece.

So, (1) which tower was that; (2) which floor does NIST say failed first in that tower; and (3) where was the next lower mechanical floor in that tower?

[vincent_vega_lives]

196. But the towers simply came down far too fast for any progressive failure.

I would love to hear your detailed reasoning on this statement.

[G Hawes]

282. Serious question. Nobody here believes that dailykoff has any legitimate expertise

in any relevant scientific field, right?

Just for clarification.

[AZCat]

284. I have not seen evidence to convince me otherwise. n/t

[G Hawes]

285. edited to say

... after re-reading your post, I realized what you meant, i.e. that no, there is no evidence whatsoever that dailykoff has any expertise in any relevant field whatsoever.

But the question still stands for everyone else in this thread. Do any of you think that dailykoff has any expertise whatsoever in any relevant field whatsoever? I think that the answer is "no" but this is a legitimate question seeking legitimate responses.

[Realityhack]

337. I see no reason to believe he does. n/t

[wildbilln864]

310. kick! n/t

[William Seger]

311. Why do you want to embarrass dailykoff again?

I think she's been humiliated enough over this one.

[wildbilln864]

312. practice that more!

Thinking that is! Maybe one day, you'll get it right!? :shrug:

[dailykoff]

313. Thanks bill!

I'd be more than happy to revisit, review or dispute any of the points raised above!

:hi:

[Rosa Luxemburg]

321. and a tornado of hot air and smoke and ceiling tiles and bits of drywall came flying up the stairwel

so I thought the 'planes' hit the top of the tower?

[William Seger]

323. It's a known fact

... that there were "secondary explosions" of jet fuel in the elevator shafts. William Rodriguez gives a very graphic account of seeing one of the victims downstairs, and the explosions and fires in the lobby were well documented (including in the Naudet video). But I take it you're one who believes those were "bombs" in the basement -- and then an hour to an hour-and-a-half later, the buildings fell?

[Rosa Luxemburg]

325. stairs

[William Seger]

326. Yes, stairs. The ones next to the elevators

[Diane_nyc]

332. Why don't you think the columns could have just broken at the weak points, i.e. the splices?

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=212263&mesg_id=212808">Here, dailykoff wrote:

The NIST report is an appalling piece of shit.

Totally deceptive, mostly by omission. I've read it, I've posted on it, and I've seen no evidence that AZcat has ever read anything but digested flak in trade mags.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=212263&mesg_id=212818">I asked for links to dailykoff's specific criticisms of the NIST report. Then http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=212263&mesg_id=212870">dailykoff referred me to this thread, http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=127965">Why existing 9/11 photography proves beyond doubt that the Trade Center was DEMOLISHED, in the O.P. of which dailykoff wrote:

the columns that can be seen flying out of the buildings before and during the collapses, and can later be seen lying or standing in the debris, are clearly UNDEFORMED, i.e., have not experienced any kind of load failure.

Perhaps most of them just broke apart at the column splices?

dailykoff, you didn't reply to http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=128009">this post by William Seger. I would be interested to see your reply.

Also, you didn't address this particular issue in http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=130296">your reply to http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=128118">this post by TheWraith.

[dailykoff]

334. Hi Diane, those are all good questions, so let me take them one at a time:

1. "Why don't you think the columns could have just broken at the weak points, i.e. the splices?"

Well, the core column connections were welded, and welded joints are usually stronger than the members they join, which explains why the surviving core columns appear to have been cut with a torch or cutting agent, as in this well-known photo:



The perimeter columns, on the other hand, were bolted, and do in fact appear to have blown apart mostly at the bolted connections.

2. "I asked for links to dailykoff's specific criticisms of the NIST report."

The discussion I had in mind begins in post #235 above:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=131889

What I'm getting at there is that the NIST deliberately obfuscates the construction of the floors by focusing almost exclusively on the trusses and omitting specific information on the number, size, and design of the beams. That's the omitted information I was talking about yesterday.

3. I don't know exactly what Seeger is insinuating in this post (#27), but his observation is basically the same one I was making in the OP, namely that the columns visible in the collapse and debris photos appear to have been severed by lateral forces -- strongly suggesting explosives -- or cut, and show few or no signs of buckling.

4. TheWraith's comment (#49) is one big hairball of OCT theories and excuses, but I did try to straighten it here (#186):

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=127965&mesg_id=130296

If there are any specific points I didn't get to, let me know and I'll try to clear them up, cheers dk :hi:

[leftofthedial]

333. what are you? a wacko, or just an America hater?

why is it so hard for you people to believe that a bunch of ay-rabs rolled double sixes twenty-nine times out of twenty-nine on 9-11?

sheesh. :eyes:











:sarcasm:

[dailykoff]

335. Both?

:wow:

[danielet]

338. thank you, I'm reading several books on this now. Congress should look

[dailykoff]

339. Thanks I hope it helped. The sad fact is that the OCT

(official conspiracy theory, in other words, the official story) is physically impossible, and the WTC "collapses" were exactly what they looked like, carefully planned demolitions using extremely powerful explosives.

The tragedy is that those thousands of innocent lives were snuffed out purely for the political and financial profit of the uber-rich plutocrats who have been making a mess of the world for the last fifty years.

[SDuderstadt]

340. Why wasn't there any evidence of controlled demolition at GZ then?

Brent Blanchard had crews onsite for weeks after 9/11 and they found ZERO detonators, ZERO det cord and the other things that would have been necessary to take down the buildings. You know, Brent Blanchard of ImplosionWorld (you know, an actual expert).

[dailykoff]

341. There was, and plenty. That's the whole point of the thread.

The evidence is the undeformed columns in the debris, and there must be thousands of photos of them.

[SDuderstadt]

342. And that would prove controlled demolition how? n/t

[dailykoff]

343. It proves the buildings didn't collapse under their own weight.

If they had, there would have been roughly 63,360 buckled columns in the rubble. However, there are few if any buckled columns in the debris photos, and I have yet to see one showing a buckled core column. So if the buildings didn't collapse, they were either demolished with explosives or stricken by divine Providence, which seems about as likely as the OCT.

I go through this in a little more detail in the OP. :)

[SDuderstadt]

344. Jesus, Dailykoff...

on the basis of looking at some selective photos, you've concluded there are very few buckled columns? Did it ever occur to you that there are a number of columns buckloed beyond recognition in the numerous "meteorite-looking" blobs of compressed building materials?

[dailykoff]

345. You asked for proof, and you got it. If you have debris photos of buckled core columns,

by all means post them. The fact is that this thread has been up for more than a year and a half and I have yet to see any evidence of the 10,780 buckled WTC core columns that would have resulted from a "progressive collapse" such as the one theorized in the NIST report and elsewhere.

[William Seger]

346. What he got was ...

... A) proof that you don't understand buckling in the first place (since you yourself posted photos of buckled core columns but were incapable of recognizing them due to your misconceptions, even after you yourself posted a link to a page that explained it pretty well);

B) proof that you simply cannot understand how the building was mostly destroyed by being ripped apart at the connections, not by buckling columns, which is very clear to see in the photos and videos and very easy to understand by anyone with common sense;

and C) proof that your knowledge of structures and steel construction is virtually non-existent.

Your "conclusive evidence of premeditated murder" is based on absolutely nothing but your own ignorance and stupidity. And I don't use the term "stupidity" lightly; your ignorance would be correctable if it weren't for that. You aren't just an embarrassment to DU; you're an embarrassment to the "truth movement."

[dailykoff]

347. forget it, delete.

I'm not here to bicker.

[dailykoff]

348. If you have debris photos showing 10,340 buckled core columns, please post them.

So far I haven't seen them.

[SDuderstadt]

349. I don't think anyone seriously believes you made much of an effort...

to find the evidence that disproves your premise, DK.

[dailykoff]

350. No one has posted them because they don't exist.

If the towers had actually undergone a total "progressive collapse" such as that proposed in the NIST report, the evidence would be visible in every photo of the debris, both on and off the site, just as it would be had they burned to the ground in a fire.

But they didn't burn and they didn't "collapse." They were blown apart by explosives, and that, in fact, is what is manifestly clear in nearly every shot of the debris.