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An email from a Conspiracy theorist, and I have no idea how

Interesting reactions on this forum. Many believes anything and do not like open discussions.

Before I start with the analysis of your claims, I'd just like to ask a few questions.

1) If we believe anything without critical thought or analysis, why don't we believe you?
2) If someone were to come onto an internet forum, fail to address arguments presented to him, and routinely declare discussion points "off topic" instead of addressing them, would you call him a facilitator of an open discussion? Do people who do that really facilitate open discussion?
 
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Have you seen the core columns arrangement of WCT2? I was there a couple of times before the collapse on various floors. Looked very strong.

That's a very strange statement.

Care to clarify?
 
You have actually seen the details behind the FEA? Have you seen how they arrive at the assumptions of boundary conditions and loads?

In your FEMs, do you perform coupled heat transfer/structural analysis?

Lurker

I have no problems to establish the actual conditions of structural parts and their boundary conditions before impact. The model is just the damaged floors and the intact section above. All parts are beams except the core box columns that are FE. The loads I know. After the impact the structure stands and I can model that by removing the damaged parts as proposed by NIST. The model is stable. But then it becomes complicated.

I assume that the perimeter columns are not affected by heat as they are outside the fire. I also assume the core columns are not affected by the heat (because it it unclear how hot it was at the various columns). NIST suggests that the floors sags due to heat and this I can model in different ways as long as the boundary conditions remain unchanged, i.e. the floors are connected to the columns. I can manually change the truss material properties. The vertical load on the trusses is small so sagging is small. The model is still stable. I can also model what happens if some trusses cool down again. The situation improves.

But if the floors starts to detach from the columns due heat + sagging I cannot model that because I have no idea if, where and how it takes place. Everything becomes guesswork. But why would the trusses be ripped of the columns due fire long after the impact? Has it happened in other fires? So I assume the floor trusses do not detach from the columns. The model is thus stable. The function of the trusses (+ concrete) are just to support the columns. Axial loads (tension) are transmitted by the trusses even if sagged but they are small.

I can remove the perimeter columns of the east wall (assumed buckled and not connected to the Trusses/floors) and observe the load re-distribution. The weight of the intact section above is shifted to the remaining walls and the core and the model still stands. No global collapse ensues. There was plenty of redundancy, it appears.
 
interesting he would have access to the core column arrangement of the WTC. Was that part of the standard tour...lol

TAM:)
 
Good question. As I didn't see the incidents in person, I can only study the effects (holes in WCT1,2, Pentagon and a Pennsylvania field and rubble everywhere) and try to establish what caused them.

Ignoring the heaps of witness testimony who actually saw the planes hit the Twin Towers and the Pentagon - not to mention that the NY planes were caught on video - which should help give a clue as to what actually exploded at and in those buildings.

Oh, or let me put it like this:

Do you believe that videos that show planes hit the Twin Towers are forged?

Do you believe that the witnesses who saw a plane hit the Pentagon are lying?

Two rather simple questions.


Cheers,
SLOB
 
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I don't know how to quote above with sub-quotes but here we go.

The first thing you should learn is not how to quote, but how to read. Many of the things you state below are adressed in the post you were responding to.

There was no load on the floors above, except their own weight + furniture.

Which is already compromising when the head makes the steel useless.

Why concrete floors + steel trusses would then sag due to heat is beyond me but it will not be much. I know steel expands due to heat ... but concrete!! No way.

You do understand how floors hold together, don't you ?

The floors were >95% concrete.

>95 % ?

And that combination supported the perimeter columns regardless of any sagging.

Precisely. So what do you think bore the brunt of the stress once they started to sag ?

And we can SEE the sagging on the pictures and videos. How can you ignore that ?

Sorry - one (east) wall - supporting only 12.5% of the total load cannot initiate total global collapse.

Yeah, I'm sure that top section would've held just fine without those walls. :rolleyes:

Why - the other structure, particularly the core, will easily support the load transferred to it. Basic. It is seen on the photos! The east wall is deformed ... and the other parts are intact. The tower stands.

So your reasoning is that if the tower didn't fall immediately following the impact, it shouldn't have collapsed at all ??

And suddenly the whole thing explodes!

The word you are looking for is collapses.

But videos of the roof - far above - shows that it sags a little before that = the 47 core columns apparently failed before the east wall.

There is no reason to believe that the core columns failed and caused the collapse. I told you:

We can see the core STILL STANDING after the collapse of the perimeter is completed.

Similar to WTC7? Strange case. But support for Controlled Demolition.

Only if you assume that a CD is the only way to produce this effect.

It would have been easy to check why the 47 off 400 metres tall core columns failed by proper forensic examination. But it was not done. This is why I suspect an Inside Job.

And that's funny, because the REASON why it wasn't done is because there was no REASON to suspect foul play. We SAW the planes crash into the towers, we SAW the effect of the fires on the structure and NOTHING in the collapse is suspicious. Why the hell would you suspect foul play ?

And it is easiest decided by a re-hearing of the whole case in a law court. I actually believe in the Law of Justice. Do you?

Yes, and your theories would be laughed at by a judge.
 
So what? The vertical load on the floor assembly was only 20 kgs/m² = furniture and outfitting.

Who cares ? The metal EXPANDED without the need for excess weight.

Also, please don't forget that the floor itself has mass, and that heat doesn't help steel to withstand that.

Why would the fuel stop inside the building, if it arrived at 800 kms/h?

Actually, that's a false dichotomy. The fuel was spread.

To me the impact looks like an explosion ... and not a plane impact. A plane impact would look completely different.

Evidence ?

And what do you think an explosion is ?

It is alleged that the temperature was high, so the steel and the concrete warmed up and material properties changed. And that the floors above impact sagged. But where is the evidence?

The evidence is, this is how things work.

It seems on most photos that the fire was gone long before the sudden collapse ...

Then what was all that smoke doing there ?

The small fires we see on photos are negligible. Just to roast a chicken on!

I don't know why you feel the need to mock the events of that day.

So I assume most heat had escaped with the smoke, the temperature had fallen as fresh air was sucked in.

Actually, that's not how fires work. Fresh air doesn't help.

So no global, sudden collapse could ensue.

Engineers and experts around the world disagree with you.

What a sloppy explanation of the collapse. It just ensued.

Yes. It ensued. I don't think that word means what you think it means.
 
So my learned fellow offshore worker( not) maybe you can start your open discussion by explaining to me why on earth I should listen to a word you say. Why should I listen to somebody who is trying to tell me that every single event that took place on 911 is not as it seems? You are the detective you are the one doing all the investigating , not me, I have no such delusions of grandeur, this is because I believe everything I am told, oh wait...... except your bunk that is.

If you have read the 9/11 Commission report about all events that took place on 9/11 prior impacts as I assume you have, do you believe everything in it? I do not (and millions others). It is too much fiction and fantasy in the report.
But my main interest is the analysis of structural damages after impacts, i.e. the results of forensic examinations ... or the lack of them.

WTC2 was the first tower that collapsed. I assume the people trapped in the section above thought they were safe and that the tower would not collapse as the fire slowly went out. But then WCT2 suddenly collapsed ... and NIST is coming up with some suggestions why that we are discussing. Controlled demolition is evidently not investigated by NIST.

The people trapped in the WCT1 must have been horrified when WTC2 collapsed. I assume they concluded their tower would also collapse ... and some desperate persons decided to jump before that, etc. Terrible.

I see no harm in discussing WTC2 and what happened to its structure after impact and prior to the global collapse that ensued.

NIST alleges that the east wall suddenly buckled and that there was load redistribution which caused the collapse. But it is not certain. Very little is certain.

NIST says that the intact section above tilted 7-8° to east prior collapse, but then the west part of the tower could not really be damaged as it was. And where did the intact section land?

With all respect to NIST they should have spent less ink/paper on the design, construction, maintenance and fire protection of the tower and descriptions of fires after impact and prior collapse. Much more efforts should have been spent on the structural conditions of the tower after impact and prior collapse and forensic examinations of the rubble that could explain the collapse.
 
Heiwa:

with all respect to you sir, NIST was mandated to do those exact things you have said they should have spent less time on. Should they have gone against that mandate, and if so based on whose request or suggestion? They were never asked to be a forensic investigation, despite what the truth movement seems to think they should have been.

TAM:)
 
The people trapped in the WCT1 must have been horrified when WTC2 collapsed. I assume they concluded their tower would also collapse ... and some desperate persons decided to jump before that, etc. Terrible.

So a) nobody jumped prior to the collapse of WTC2 and b) nobody from WTC2 jumped?

Is this correct?

Cheers,
SLOB
 
That's a very strange statement.

Care to clarify?

In the 90's I visited American Bureau of Shipping (93rd floor?) and some other companies high up in the WTCs and I am always curious about escape routes, fire protection, etc. if the lifts fail, fires break out, etc. so I had a look around. Also interior decoration ... how to hide the supporting columns in the entry hall at every floor. I was quite impressed but would never work in such a tower.

Actually the purpose of the visit to ABS was to discuss a better, safer and more environmentally protected seagoing oil tanker design that spills zero oil in most incidents - the Coulombi Egg tanker! http://heiwaco.tripod.com/ce_coulombiegg.htm . In 1997 the United Nations International Maritime Organziation approved it as an alternative to double hull according international rules. Quite an achievement! It is the only design that has been so approved by the IMO. Unfortunately one member of the IMO did not agree! The USA. So USA had to abandon the international rules and make their own rules.

You can note that the Coulombi Egg design is based on data of actual incidental damages to oil tankers! Most collision damages are actually located only above and in the waterline, so the Coulombi Egg logic was to maximize the protection there. The USCG apparently disagreed. They thought a flimsy, uniform 'protection' all the way down to the bilge (double side) was better. It was very easy to demonstrate the opposite. The USCG was not happy. Strange case.

But above explains my interest in the WTC2 collapse. What caused it? How to prevent it happen again.
 
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I assume that the perimeter columns are not affected by heat as they are outside the fire.

That's quite an assumption ...

WTC1latefires.jpg


I also assume the core columns are not affected by the heat (because it it unclear how hot it was at the various columns)

You don't know how hot it was, therefore you assume room temperature?
Er .....
 
Good question. As I didn't see the incidents in person, I can only study the effects (holes in WCT1,2, Pentagon and a Pennsylvania field and rubble everywhere) and try to establish what caused them. Witnesses have given many different testimonies of what happened just before the impacts so I leave that analysis to others. It seems that forensic documentation of parts from any objects hitting the various locations is sloppy, so I have given up analysis of that too.
Thank you for your honest answer. As I don't waste time with people who can't figure out if airliners were used in the 9/11 attacks, I wish you well in your pursuits and bid you goodbye.
 
And here I thought Heiwa was an NWO disinfo agent/explosives specialist who was part of the CD team for the towers...

Oh well, welcome to the forum, a litte belated, Heiwa.

TAM:)
 
I am a structural engineer specialized in shipbuilding. I have inspected many ships built of steel damaged by fire and overload of various kinds.
I don't care. I care about mathematics, evidence and logical analysis.
None of these ships or their structures has ever collapsed by fire. Deformed, yes. I have some observations regarding the WTC2 collapse that may be of interest:
This point has been shown in error.
The NIST NCSTAR 1-6D report suggests that the WTC2 collapse was due to the following:

"Buckling of East Wall and Collapse Initiation

With continuously increased (sic) bowing and axial loads, the entire width of the east wall buckled inward. The instability started at the center of the wall and rapidly progressed horizontally towards the sides. As a result of the buckling of the east wall, the east wall significantly unloaded, redistributing its load to the softened core through the hat truss and to the south and north walls through the spandrels ( …). The section of the tower above the buckled wall suddenly moved downward, and the building tilted to the east ( …).


The section of the building above the impact zone tilted to the east and south (observed at about 7° to 8° to east and about 3° to 4° to south, …) as column instability progressed from the east wall to the adjacent south and north walls. The release of potential energy due to downward movement of the building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse ensued (sic)."
That's page 321 in case anyone else is following along.
According to other NIST reports the total mass above was supported as follows:

50% - by the 47 core columns.
12.5 % - by the south wall columns (abt 80)
12.5% - by the east wall columns (abt 80)
12.5% - by the north wall columns (abt 80)
12.5% - by the west wall columns (abt 80).

A side note here, the corner columns of the WTC complex held, by themselves, about 1/5th of the load on the core. See NCSTAR 1-1, page 8 for details on the structural subsystems.
About 80% of the wall and core columns were intact after first impact according NIST and the tower structure carried the mass above.
Again, columns that were in tact did not necessarily have the same load capacity as they did before impact. Your analysis seems to hinge on the idea that any in tact column is still capable of carrying 100% of the load. That's a ridiculous assumption.
Then there were fires in the office spaces between the core and the outer walls. The outer wall columns were always cooled by fresh air so they were unaffected by the heat.
Excuse me? Just because a column is cooled by fresh air on one surface does not mean it is impervious to effects by heat. That is a wildly inaccurate statement. Section 3.2.1 shows NIST's analysis of the heat effects in the exterior wall for WTC 1.
We are told that the east wall, that carried 12.5% of the mass above, buckled inward due to axial loads some minutes before the collapse, which BTW are constant and not increasing, as suggested. The buckling deformation is not big as there is still some support from floors inside.

Actually, we're told that the columns on the east wall buckled due to a combination of increased axial load and increased out of plane loading due to floor sagging. These are the infamous "pull in" forces that are discussed, oh, maybe 100 times in 1-6D. Read page 310 for further details. It seems as though you're intentionally misrepresenting NIST's findings.
Second, while the collapse happened suddenly,
We are then told that the east wall significantly unloaded but not how much.
We are told the column loads prior to buckling.
Let's say that 50% of the load on the east wall that originally carried 12.5% of the total mass above, i.e. 6.25% of the total mass above is now redistributed to (i) the core, and to the (ii) south and (iii) north walls through connecting structure.
That's complete nonsense. You've pulled that number out of thin air and assumed that it completely redistributes to areas of the WTC towers which you assume are undamaged by fire. How does that assumption have any basis in reality?

NIST describes, in detail, a load cycling from damaged exterior columns to less damaged exterior columns, and further to the core columns. It is a cycle which catastrophically collapsed when load redistribution failed. 30 minutes into the collapse, creep strain was already buckling core columns where the temperature stresses were high. See pages 313 to 318 for the details.
So 6.25% of the total mass above is redistributed. What happens?
It is redistributed to an area heavily damaged by fire. An area that, by the way, continues to shed thermal load onto the exterior columns via the Hat Truss system. Load can't cycle both ways, and when one system fails, all of them do.
Say that 50% of that or 3.125% of the total mass above is redistributed to the core; it will then carry 53.125% of the total mass above. Thus the load on the core increases 6.25% after the alleged redistribution.
Again, you pulling numbers out of thin air is not convincing.
We are told that the core is 'softened' which is not scientific but maybe it was affected by heat.
Maybe? Maybe it was affected by heat? Did you read any of the NCSTAR? Do you understand anything about fire or the effect of heat on steel?
However, half of the core columns were far away from any fires so they could hardly have been affected.
Excuse me? You're talking about load redistribution, and you assume that the only way a column can be damaged is if it is directly damaged by fire or impact? What about load redistribution? Do increased loads and additional thermal stresses also deform and damage columns?
But as the core columns had resisted the fire so far, a load increase of 6.25% due to redistribution could not make the core collapse!
Wow! An argument from personal incredulity! Not only that, you're assuming that because the core columns were able to carry the increased load directly after the impact, they should have been able to hold the weight indefinitely. That's silly.
25% of the redistributed load or 1.5625% of the total mass went into the south and north walls respectively that now each carries 14.0625% of the total mass above. Thus the load on the south and north walls increased 12.5%. These walls were not affected by fire as they were cooled by fresh air. There were some damage to the south wall, but again it did not collapse at impact, so a load increase of 12.5% will make little difference. No deformation of any kind is seen on the north and south walls after redistribution.
Once again, you making up numbers is not a convincing scientific argument.
Global collapse could therefore not ensue due to such load distributions because there were too much redundancy and safety factors built into the outer wall columns (wind, lateral loads, etc) and also in the core columns. You could maybe expect further deformations of structure finding a new equilibrium and the tower may have tilted a little and stopped in that position but sudden global collapse is impossible due to the alleged load distribution!
Ok, your argument was based on the idea that redundancy could have handled the impact of the aircraft and the increased thermal stress due to fire indefinitely. Yet you provide no mathematics to prove it, and your best effort is to make up numbers, fail to account for thermal stresses, and assume infinite load distribution on a static system.
Actually there is no evidence of any sort for the statement "Global collapse ensued".
I can't tell if this statement is sarcastic or stupid.
It is only wishful thinking by incompetent and/or complacent NIST engineers. They know that no steel skyscraper has ever collapsed due to fire!!
So, hundreds of the world's best civil, structural and materials engineers are wrong. As are their academic, professional and international collaborators, reviewers, and the various professional societies to which they belong. And your belief is that they're incompetent.
So what happened? Controlled demolition, CD, from top down? It seems that WCT 2 47 off core columns were damaged first, as the tower actually falls in its own footprint. The outer wall columns break afterwards like spaghetti by the floors being pulled down by the core columns. It seems that the core columns were broken by CD at every 10th floor, or so. NYFD staff noted these explosions, bang, bang, bang just before collapse ensued.
I would implore you to take a logic class. On your first day, the first words from your teacher's mouth will be, "Universal affirmatives can only be partially converted." The fact that all explosives cause explosions does not imply that all explosions are cause by explosives.
It would have been very easy to recover all the bits of the core columns from the rubble and assemble them on a 400 meter long field to verify (a) in how many parts each column split during collapse and (b) how the surface of the broken areas looked like.
I'm glad that your opinion is that it would be "very easy" to recover the core columns. It's too bad no one cares about your opinions.
CD would probably have cut of the core columns sideways to dislocate them so that they could just drop down pulling other structure with them.
That would have caused a radically different collapse than the one seen. The core of WTC 1 and WTC2 remained standing for several seconds after the exterior of the building had collapsed.
Alternatively complete pieces of core columns were blown away. In either case a forensic examination of the core columns would have explained the collapse.
A forensic examination was completed. It is the subject of a 10,000 page report completed by the most advanced and experienced building fire research lab in the country.
If the collapse was due to release of potential energy overstraining the core pillars, the broken areas would look completely different.
I don't care about your opinion.
But as no complete forensic examinations were done for unknown reasons we must find other means to establish the real cause of the collapse. Easiest is of course a complete re-hearing of the case by a competent law court.

Wow! So, lawyers are better able to judge the technical veracity of the NCSTAR than engineers and scientists in the field. I had no idea that the courts were in the business of establishing scientific truth!
 
As I didn't see the incidents in person, I can only study the effects (holes in WCT1,2, Pentagon and a Pennsylvania field and rubble everywhere) and try to establish what caused them. Witnesses have given many different testimonies of what happened just before the impacts so I leave that analysis to others. It seems that forensic documentation of parts from any objects hitting the various locations is sloppy, so I have given up analysis of that too.

So where did all those dead bodies come from?
 
Nobody has so far explained why a small load distribution caused total collapse

Maybe because it's a strawman.

so I assume we all agree that NIST suggestion is wrong.

Sorry, no cigar.

Regardless - the undamaged section above the impact zone obviously lands on top of rather on the east side of the remains of the tower that globally collapsed (for unknown reasons) below it.

Again, you're assuming your conclusion. The tower "below it" collapsed because 40 floors were crashing onto it.

Did it? I assume that the undamaged section above the impact zone should have landed more or less on its east wall side with the west wall on top, i.e. after the total collapse of the tower, we should have observed 100 metres of west wall columns on the east side of or on top of the rubble.

Well, then it's a good thing that the people making the REAL analyses are those who know what they're talking about.

Did anybody? Under the 100 metres of west wall columns, we should find 100 metres of 47 centre core columns, etc. They should be more or less continuous, i.e. one piece each but maybe deformed. It would have been easy to see how these core columns were torn apart at the impact zone.

Why the hell would you expect that ?

But strangely enough it was not done. No forensic examination was done of section above the impact zone. It seems, which many observers have noted, that the intact section above the impact zone - four walls and its core - disintegrated in air between times t1 and t2. How to explain that? NIST does not explain it.

Again, why should they ? Something that massive won't stay in one piece for long when such forces are involved.
 
Anyway - global collapse was prevented for some time, so the structure was not too bad ... until it suddenly disintegrated due load redistribution.

Again, why do you assume that the damage was not progressive ?

Of course I am an engineer

A garden engineer ?

Interesting reactions on this forum. Many believes anything and do not like open discussions.

That's funny because that's exactly what we're doing. Discussing.

But if the floors starts to detach from the columns due heat

Again: who said anything about detaching, except you ?
 

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