WTC Core...

[wildbilln864]

short video. This person's videos are very good. Check them out.

[wildbilln864]

1. kick. nt

[RC]

2. Where is ever body? Must be at an emergency meeting at the

Operatives secret location. :rofl:

[LARED]

3. Nope, just an another pointless video

Is there something worthwhile to comment about?

[RC]

4. Yep!

Where'd all those uprights go to if if the government's line is correct?
There is absolutely no pictures or evidence in any videos that they were still intact at any level after the collapse.
How could this be? Those columns were tied together in a rigid framework and the buildings should have collapsed around them, leaving them standing 40 to 60 feet in the air if the government's pancake theory were true.

[hack89]

5. How flexible do you think those joints were?

how many degrees of deflection before they failed? The collapse was an indescribably violent event involving incredibly massive chunks of metal falling at tremendous speed. That core would have been battered and pulled to pieces.

You have a cartoon view of the collapse - I understand it takes effort to understand complex events but in some cases that's what you must do to find the truth.

[RC]

6. I don't think you have any understanding of the strength of hollow tubes

and of the strength of steel used in buildings.

Why would the core be pulled to pieces? The floors should have been going straight down around the core. It did collapse into its own foot print. The buildings did not fall over, They both came straight down. The floors were held up by trusses attached from the outer core columns to the outside building supports. The core was massive and they were all tied together and yet none of the columns were left standing? Not even the biggest center column. There was no way all that steel was fire softened all the way down.

Answer me this: There are videos that show the first tower collapsing from the very top down. From the TOP DOWN... Above where the plane hit. How can that be? There are several different videos from several sources showing this happening. That undamaged section above the impact should have remained intact, riding the building under it down to the ground. It did not. The upper levels collapsed first, the collapse going down through the damaged area, through the rest of the building, all the way to the ground.

That "cartoon" as you call it was computer generated simulation using programs designed for What-if scenarios for the real world where it would be impractical or impossible to duplicate in the real world due to costs. It is used to test building designs for stresses and failures. I doubt you you could afford to buy the software involved or the computers needed to run them.

[Realityhack]

7. Wow...

that is one hell of an oversimplification.

Then again so are this guys videos.

If you understand the simulation you can easily see it is a horrific oversimplification that demonstrates absolutely nothing.

[Name removed]

8. Deleted message

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

[RC]

14. Over simplification? You were maybe expecting little workers running all over the place

putting those little pieces in place? It was designed to be simple so non engineers, i.e., the general public could better understand how the building was put together and how it really collapsed. But then you already know this.

[Realityhack]

20. "It was designed to be simple so non engineers..."

And yet he passes it off as an engineering model. It isn't. It is an oversimplification in the extreme.

And it certainly does NOT show 'what really happened'.

[hack89]

12. Since the tops tilted

how can you say that they fell straight down? How much rotational energy do you think was transmitted to the core?

Are you saying that no debris fell on the top of the core columns as the top of the towers fell? How much do you think a 30 story section of the WTC weights? Once the core was deflected by a huge mass falling on it and its lateral support was removed, it would have disintegrated into 30 foot sections as all the joints failed. The steel is strong - the joints not so.

[hack89]

13. You are kidding, right?

That undamaged section above the impact should have remained intact, riding the building under it down to the ground

That section fell 12 feet, crashing into the intact building below. How much KE do you think was involved in that collision? The tops were twisting and falling asymmetrically - the were ripped apart.

[RC]

15. The complete quote

"Answer me this: There are videos that show the first tower collapsing from the very top down. From the TOP DOWN... Above where the plane hit. How can that be? There are several different videos from several sources showing this happening. That undamaged section above the impact should have remained intact, riding the building under it down to the ground. It did not. The upper levels collapsed first, the collapse going down through the damaged area, through the rest of the building, all the way to the ground."

[hack89]

19. That's what you would expect

why do you think the engineering community accepts the NIST reports? They understand the science.

What do you think was going to happen when the upper levels lost their vertical support?

[LARED]

9. I would try and explain this but, it would be pointless. You have made

up your mind.

[RC]

10. And you haven't made up your mind?

The questions I ask, I expect not to be answered, because you and your buddies can't answer truthfully. That would raise too many other questions.

[LARED]

11. Yes, I have, I am certain that

the WTC'ers were brought down by planes and fire. This is established knowledge. There is significant science and evidence to back up this belief.

[RC]

16. OK...

I can't argue that what you said is established knowledge. It is not really factual, but it is "established knowledge".

The science to back this up has been hacked to allow the reprobates who planed and allowed 9/11 to happen the pretest of innocence.
Maybe you want to reasearch Larry Silverstein for a start?


http://911research.wtc7.net/wtc/background/owners.html
http://www.youtube.com/watch?v=7WYdAJQV100

[AZCat]

17. IIRC links to "whatreallyhappened" aren't allowed at DU.

You might want to find another source for that article.

[Bassman66]

18. Giuliani knew the WTC was coming down.

That's an amazing (unbelievable) but true fact - he says it on this news interview:

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

Yeah I know... "someone in the OEM told him..."

How did they know?

Amazing.

Nothing to see here folks.

[Bassman66]

21. He really did.

How come?

[RC]

22. It's in a video. Videos aren't sufficient evidence down here to prove anything

:sarcasm:

[Bassman66]

23. The OCTers must not be able to see this one nt.

[Make7]

24. Giuliani knew the WTC was going to come down?

 
http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=125&topic_id=158196&mesg_id=158196
 

[Bassman66]

25. Yes he knew - he said so.

How did he know?

Oh.. yes.. "someone" at the OEM was putting out the message.

"I said, listen, I was just at OEM. The message I was given was that the buildings are going to collapse;"

That's from one of your posts.

How did they know?

Where is this discussed in the 9/11 CR?

Oh that's right.. it's not.

[wildbilln864]

27. but, but, but...

how could they possibly know the building was going to collapse? After all 9/11 was a complete surprise attack, right!
Rockefeller knew!

[Bassman66]

28. Good question - how did he know?

Why did he then lie about it?

Did the 9/11 CR mention any of this?

[wildbilln864]

30. My guess...

he knew because he is one of the elite who know of all these covert operations aimed towards NWO. Why he lied? How could he admit it? Russo is dead so he can't defend himself now.
No the commission didn't.
:hi:

[SDuderstadt]

31. "NWO".....LOLOLOLOL

I shoulda known Bill was into this fantasy. This explains a lot.

[Bassman66]

40. New World Order - a phrase oft used by Bush

So stick your LOL!

[LARED]

42. Not that I give a rats rear end what Bush says, but can you provide

any evidence Bush is oft using the term "New World Order".

[Bassman66]

43. Are you serious? Poppy loved it. nt

[LARED]

44. I remember Bush 1 pretty well and he did say it a few times,

but it was hardly a theme of his administration.

[Bassman66]

45. Yes Bush did use it a few times didn't he!

Remind me who was working for him at the time... oh that's right.. same people working for sonny.

[SDuderstadt]

49. A phrase often uttered by George W. Bush?

Please prove that. George H.W. Bush made a passing reference to a "new world order" and was clearly referring to the advent of democracy around the world and was hardly talking about some sort of Bilderberger/CFR/United Nations/Illuminati fascist takeover of the world. This is why you conspiracy types are so laughable and, frankly, embarrassing.

[Bassman66]

56. Apologise. You are dissembling once again.

I never said George W Bush.

However.

The phrase "New World Order" is not a novelty in the Bush household.

LOL - stick it.

[SDuderstadt]

58. Duh.

That's why the headline of my response was phrased with a question mark, because it wasn't clear whom you were referring to. Don't blame me for your lack of clarity. It should occur to you to if you just say "Bush", it's more likely, in the absence of any clear identification, that you're probably referring to the current president.

As I pointed out in my reply, George H. W. Bush made a passing reference to a "new world order" and you CT's have blown it way out of proportion. Pathetic.

[Bassman66]

61. My lack of clarity was deliberate, "Duh".

LOL - stick it.

"New World Order" - LOL.

yeah.. it's mad.

[Bassman66]

26. But you know the best thing...

...he later lied and said he never said any such thing.

But he did.

[hack89]

32. So why did they wait until the last second to tell him?

and why would he admit he was part of the plot?

[Bassman66]

41. We don't know anything other than what he said.

He said he knew.

Then he later denied he said it.

I don't actually believe what he said is the real truth.

I think we need to find out the real truth.

It appears that from one other witness someone in the OEM was spreading the message that the WTC was going to collapse.

How did they know?

[zipplewrath]

29. There is no "pancake theory"

I've checked my structural design theory text books and I can't find any description of a "pancake theory". There are several which will discuss the problems associated with "column buckling". One of the main contributions to failure was the buckling failure of the columns. Buckling is a stiffness (not strength) driven phenomenon and it is best described as an almost instantaneous loss of ability to resist load (actually it technically is merely a dramatic reduction in load capacity but for this case the two are relatively the same). Now, those columns were connected between the inner and outer sections by the floors. When floor connections are compromised (either by initial impact or by the subsequent fire) the "apparent length" of the columns appears to double (or more if multiple floors are compromised). As one doubles the length of a column, it's load capacity reduces by a factor of 4. Once enough columns are compromised (either by failure of the connection to floor supports, or through reduction in stiffness of the steel which can happen with as little as 500F for 30 minutes) buckling will ensue.

The effect of buckling will be an apparent total loss of resistance to motion. No particular resistance to motion will be experienced again until the floors have transversed through the roughly 20 feet of distance between floor structure. There is something called dynamic load factor which amplifies the force a mass can generate because of it's velocity. Just moving a mass in free fall through a couple of inches will more than double the force it can generate. A simple way to think of this is that gravity will accelerate something at 1g. Whatever distance it falls through, is the distance it will be required to stop it by applying 1 g AGAINST that motion. If something falls 20 feet, and you want to stop it by applying 1 g, it will have to be applied over 20 feet. If you want to stop it in a shorter distance, you'll have to apply more deceleration (4, 5, 6 gs) over that shorter distance. Stopping a mass in 1 foot after it traverses 20 feet requires vastly more force than the building was capable of generating. The end result was progressive buckling failure.

[RC]

33. The pancake theory is just that, a theory, like Creationism is a theory.

What columns had their lengths doubled and how did this occur? This makes no sense.

Your explanation in the second paragraph would have resulted in a jerky collapse. Each floor would hit the one below it and slow down while all the many supports would pull loose at exactly the same time, then do it all over again at the next floor, all the way down for 80+ some stories. That is not what happen. It was a smooth collapse without any apparent resistance.

If the collapse occurred the way you described, it would stand to reason any buckling would have to occur below where the collapse was occurring, in which case the collapse could not be straight down. Any buckling would throw the alignment off as all the columns were tied together at every level. If the alignment were far enough off, the already collapse part on top, would "fall off" the un-collapsed part of the building under it and any further collapse would not be even & straight down any longer. That did not happen.

Also the building's upright core columns and outer wall were not damaged below the level of impact. As these building were over built and designed for a plane impact and resultant fire, this makes the collapse all the more suspicious.

Also keep this in mind. If the terrorist were really interested in the most bang for the buck, so to speak, then why did they not fly the planes so as to hit as low as possible into the towers in an effort to topple the Twin towers over onto other buildings?

[AZCat]

34. He means the unsupported length doubled - not the overall length.

This determines the slenderness ratio, an engineering term that is used to determine how susceptible a column is to buckling.


Your claim that the buildings were "over built and designed for a plane impact and resultant fire" is simply not true.

[RC]

35. World Trade Centers 1 & 2 were both over built and designed for plane hits.

You will notice names and work titles are included in the article.

http://911research.wtc7.net/wtc/analysis/design.html

Towers' Design Parameters

Twin Towers' Designers Anticipated Jet Impacts Like September 11th's

Structural engineers who designed the Twin Towers carried out studies in the mid-1960s to determine how the buildings would fare if hit by large jetliners. In all cases the studies concluded that the Towers would survive the impacts and fires caused by the jetliners.

Evidence of these studies includes interviews with and papers and press releases issued by engineers who designed and oversaw construction of the World Trade Center.

>SNIP<
Statements by Engineers

Engineers who participated in the design of the World Trade Center have stated, since the attack, that the Towers were designed to withstand jetliner collisions. For example, Leslie Robertson, who is featured on many documentaries about the attack, said he "designed it for a (Boeing) 707 to hit it." 2 Statements and documents predating the attack indicate that engineers considered the effects of not only of jetliner impacts, but also of ensuing fires.
John Skilling

John Skilling was the head structural engineer for the World Trade Center. In a 1993 interview, Skilling stated that the Towers were designed to withstand the impact and fires resulting from the collision of a large jetliner such as Boeing 707 or McDonald Douglas DC-8.

[AZCat]

36. You don't know what you are talking about, and neither does that article.

The debate over the particulars of the WTC design strategy regarding aircraft impacts has gone on for quite some time. The statements made and the evidence (what "evidence" there is) have long been accounted for. Robertson (who doesn't agree with you, by the way), Skilling's statement, DeMartini's statement, the PANYNJ white paper - these have all been addressed. Your statement is incorrect.

Maybe you should do a little fucking research (there are even plenty of relevant threads here at DU) before pulling crap from a conspiracy website next time.

[RC]

46. Allergic to reality based referenced facts, huh?

This is not a conspiracy site. Why do you insist on pushing the government line when it is so obvious in its fallacies?

[Realityhack]

52. AZCat is correct and you are incorrect.

This issue HAS been addressed repeatedly by people who know what the fuck they are doing. You clearly do not or you would not be posting such nonsense.

[SDuderstadt]

54. It's kinda goofy to claim a website that features....

Kevin Ryan, David Ray Griffin and Steven Jones is not a "conspiracy website".

[hack89]

37. Pull that string a little further and ask what fire modeling they did

turns out not much at all if any. Fire engineering was in its infancy when the WTC designed - any computer models were simplistic and cartoonish. Since it was the combination of impact and fires, if they didn't correctly account for the fires, then it is perfectly reasonable to think that the towers could collapse.

One huge problem was that the builders never tested the design to ensure that it meet design specs for fire resistance:

At the time the towers were built, a half-inch of spray-on fireproofing was specified for the towers. How this half-inch specification came into the final construction plans remains unclear. No full-scale fire resistance test of the floor system was ever made. In 1966 the original architect, and in 1975, following a fire in the WTC, a Structural Engineer, expressed the need for such testing, each stating that the fire rating of the floor system could not be determined without such a test. Despite their recommendations,the flooring systems were never tested.

http://www.chiefengineer.org/content/content_display.cfm/seqnumber_content/1753.htm

The debate over the sufficiency of the fireproofing on the World Trade Center's lightweight floors - essentially metal and concrete decks supported underneath by a series of inch-thick zigzagging rods - intensified in May 2003 when federal investigators concluded that the Port Authority, back in the late 1960's, apparently never performed the formal laboratory fire test on the design .

http://911-engineers.blogspot.com/2007/04/fire-testing-is-questioned-in-findings.html

[RC]

47. Too bad I'm not teaching a class on propaganda

I could use your posts as examples. Computers were in there infancy in the early '60s. So of course "...any computer models were simplistic and cartoonish."
And because they were not tested for fire resistance, that means they had to collapse in a fire. Yeah, sure.

[SDuderstadt]

51. How are his posts "propaganda"?

Please explain that.

[Realityhack]

53. I think you owe hack an apology. n/t

[RC]

62. An apology? Why, because the Alert didn't work?

I gave two examples of propaganda in my answer.

[hack89]

63. It is an article of faith for truthers that the WTC were designed

to take the impact of airliner so it is therefore impossible that they could have collapsed on 911. Don't you think the fact that the design was not tested has bearing on this issue?

I am not saying they had to collapse - I am questioning your belief that it was impossible for them to collapse. Not the same thing.

[SDuderstadt]

50. Yeah, a 707, not a 767....

It was also assumed that the plane was lost in fog attempting to land, thus carrying far less fuel and would hit the WTC at a relatively low rate of speed. You need to hone your research skills.

[RC]

64. So you are telling me they put up two 110 story buildings without

a thought of planes flying into them or any resultant fire? Buildings 1,350 in the air, minus the 365 foot antenna mast.
In that case why did they not fall over when the planes flew into them? They should have buckled. Not collapse, buckled, fall over.
You are telling me they were not designed for stuff flying into them, so the buildings should have fallen over when they absorbed the energy from the planes velocity. What happened was they swayed back and forth 5 feet or so, then returned to equilibrium.

[hack89]

65. The question was whether the design was adequate

Building and fire codes have changed significantly since 1968 for good reason - there have been tremendous advances in science, computer modeling and fire testing.

No one is saying they had fall immediately - where did that strawman come from?

[AZCat]

66. No, I am not telling you that.

It is important for you to understand the distinction between a "thought experiment" and an actual calculation. Whether the engineers attempted to determine the effects of the fires from an aircraft collision is irrelevant - they didn't have sufficient knowledge or computing power to do so.

[zipplewrath]

48. Details, details.....

"What columns had their lengths doubled and how did this occur? This makes no sense."

Well, I wasn't trying to write a technical paper. The columns "buckling length" is the distance between supports, i.e. the floors which create points of support. That's how the columns in this building "worked". The floors connected the outer columns to the inner columns and created a system of lateral supports so that the buckling strength was functionally based upon the height of a single floor. When the floor supports were compromised, this characteristic length of a column was functionally "doubled".

"Your explanation in the second paragraph would have resulted in a jerky collapse. Each floor would hit the one below it and slow down while all the many supports would pull loose at exactly the same time, then do it all over again at the next floor, all the way down for 80+ some stories. That is not what happen. It was a smooth collapse without any apparent resistance."

Actually, it is what happened but it would be difficult if not impossible to "see" on a video operating at roughly 30 frames per
second (30 Hz). I don't know the "exact" length, but the capacity of those columns (even base upon a single story assumption) to deflect under load (without buckling) is probably on the order of inches, (i.e. like one or two). That's say 2 inches out of 20 feet (i.e less than 1%). I've run numbers on columns of notional sizes for a building of these dimensions and the deformation length prior to buckling is less than an inch, but I'm willing to work with numbers larger than that and the building still collapse at "nearly free fall speeds" despite this magnitude of resistance.

"If the collapse occurred the way you described, it would stand to reason any buckling would have to occur below where the collapse was occurring,"

For various values of "below". In order to collapse a column, the force has to be "communicated" down to lower sections of the column. In order to accomplish this, the force has to "pass through" a column and if it is large enough to buckle the column, it can't "pass it through".

"in which case the collapse could not be straight down. "

The only force acting on the building (gravity) was acting "straight down". In order for the building to fall any other way, there had to be structure capable of converting that force into another vector direction. The building wasn't designed to do that. It was designed for integer multiples of the building in the vertical direction, but fractions of that in the lateral direction. (i.e it only had to handle wind and ground movement forces, not gravity forces laterally).

"Any buckling would throw the alignment off as all the columns were tied together at every level. If the alignment were far enough off, the already collapse part on top, would "fall off" the un-collapsed part of the building under it and any further collapse would not be even & straight down any longer. That did not happen."

And it would be surprising if it fell any other way. When buildings ARE intentionally demolished with explosives, they have to sequence the explosive in specific orders to create anything but a vertical collapse. i.e you have to fail "half" of the building first to generate an asymmetric collapse. Because this building wasn't set up to fail asymmetrically, it wasn't going to generate lateral movement.

"Also the building's upright core columns and outer wall were not damaged below the level of impact. As these building were over built and designed for a plane impact and resultant fire, this makes the collapse all the more suspicious."

No, it doesn't. I'd suggest you calculate a number or two to support such a statement. You'll have a hard time. I've tried. There are many methods of failure analysis and one of them is to try to establish a mechanism for the failure and then quantify it. I can't find any credible numbers to support what you wrote. Once the first failure occurred, and the building began to move, even a structure that was 4, 5 or 6 times over designed couldn't stop what happened. That is the nature of "dynamic load factor".

"Also keep this in mind. If the terrorist were really interested in the most bang for the buck, so to speak, then why did they not fly the planes so as to hit as low as possible into the towers in an effort to topple the Twin towers over onto other buildings?"

I strongly suspect, partially based upon their original attack in '93 that they were not structural engineers, nor particularly sought out the advice thereof. As was demonstrated in this attack, the lower one hit the better. (Although the building was stronger as one went lower so I don't know if there was a "sweet spot"). I actually suspect that their intention was to "knock them over" i.e. make them fail laterally so as to "wipe out" huge sections of lower Manhattan, including Wall Street. They were doomed to failure in that sense. You couldn't have done that with a crane, much less impact. It requires a certain structural capacity of the building to apply a force of that magnitude in the lateral direction that didn't exist. But a "layman" who had such an intent would tend to decide to "hit it high" in order to try to "knock it over".

[wildbilln864]

38. well I've checked....

your post and it doesn't make a lot of sense.
It'd be nice if you had some evidence to support assertions like, "the "apparent length" of the columns appears to double (or more if multiple floors are compromised). As one doubles the length of a column, it's load capacity reduces by a factor of 4."
That's a stinker there for sure.

And this: "or through reduction in stiffness of the steel which can happen with as little as 500F for 30 minutes)"
Nope! That shit won't flush.
Evidence to support such claims would be appreciated. Surely there are tables that support your assertions? :popcorn:

[AZCat]

39. It's called the "slenderness ratio".

If you didn't have me on ignore you'd know that. The slenderness ratio is the ratio of the effective length of the column to the radius of gyration. If we're talking about long, slender columns, the critical load is the ratio of the square of pi times the area times the modulus of elasticity to the square of the slenderness ratio, or

Fe = (pi^2)*E*A/((L/k)^2)

As you can see, doubling the effective length decreases the critical load by a factor of four.

[Realityhack]

55. Stop posting facts. It isn't fair to the willfully ignorant n/t

[Bassman66]

57. So how did Giuliani know?

My last go at this question got buried in LOL's.

Someone was on the ball that day, who was it?

[Make7]

59. I think that once you have over 1000 posts, you're allowed to start threads. ( n/t )

[Bassman66]

60. Wahwey! Thanks for the heads up!

1000 posts.

Wahhey!

The power!

[wildbilln864]

67. kick! nt