Failure mode in WTC towers

[GregoryUrich]

Rationalists with strong technical backgrounds have explained why the columns failed. The conspiracy liars, as always, are unable or refuse to understand.

Have any "rationalists" actually showed why the columns failed using mechanical principles? Please specify.

 

[Heiwa]

So the perimeter walls didn't bow, then buckle, leading to global collapse? Then please explain your collapse mechanism, which matches observations.

OK - the first visible sign of the WTC1 collapse is that the roof line drops, while the columns at the initiation zone floors 93-98 are intact. This goes on for, say, 2 seconds and the upper block (between roof line and initiation zone) seems to be compressed and still nothing happens below the initiation zone. Agree?

What can pull the upper block together? The mast above? Of course not. The roof is quite strong with its hat trusses, etc. Local failure of 47 core columns? OK, let them drop down! Why would the perimeter walls fall down? Aha, they were pulled down via the floors! So the floor connections were very strong. But 47 core columns suddenly/simultaneously failing??

On the other hand Nist suggests that the floor connections were so weak (700 bolts/floor) that they just suddenly sheared off allowing 6-11 lower floors of the upper block to drop down on an intact floor below.

In my view there is an early implosion in the upper block that pulls it together followed by an internal explosion that blows out debris, dust and smoke through the windows between intact columns.

This is the initiation ... and it cannot be caused by release of potential energy above supposedly buckled columns (none found/seen), etc.

 

[Major_Tom]

rwguinn scolds us:

the videos from the side show that the antenna remains attached to the top of the buliding while the entire top block rotates downward, around the hinge formed by the (thus far) undamaged, remaining columns--which immediately fail.

We have seen the west side of WTC 1 with smoke ejections along the entire 98th floor appearing simultaneously.

The smoke ejections along the 98th floor west face do not favor the south side of the building over the north side.

If the ejections along this line are taken to mean that the perimeter gives along this line at the moment we see the ejections, then the north side of the west face gives at about the same time the south side gives.

The smoke ejections along the west face don't suggest hinging towards the south.

 

[einsteen]

Bolding mine

If you base your hypothosys on a false premise, then, yes, it will be absolutely wrong from the start and in every particular.
You are now throwing out stupid--if not moronic-- ideas. The antenna did not drop first!
Only an idiot will believe that. When viewed from straight behind, it appears that happened. As you twoofers have been shown, time after time after time after time, the videos from the side show that the antenna remains attached to the top of the buliding while the entire top block rotates downward, around the hinge formed by the (thus far) undamaged, remaining columns--which immediately fail.

Quit lying. OR has it become such an ingrained habit you can't?

RW got me on ignore but I think he is right with that. That thing is attached to the hat truss which is a very rigid thing that falls, however if the core fails first I believe it is still consistent with the outside behaviour. And that is also what Mike Newman says in the phone call

http://www.pumpitout.com/audio/nist_042707.mp3

I'm not sure if that is their latest theory but it makes sense.

 

[GregoryUrich]

The disingenuous twoofer "Sizzler" started a thread positing an alternate universe where fantasists are in control. R.Mackey listed five refutations of Twoofer dogma, one of them being extremely pertinent to this thread:

"2. Video clearly shows that at the onset of failure, perimeter columns buckled inward, precipitating the collapse. This requires structural connections to remain intact rather than be blasted apart. No one has even proposed any way to replicate this with explosives."

What do the faux "engineers" have to say?

A real engineer would like to see your hypothesis supported by mechanical priniciples as opposed to a "jroofer" photo/video accompanied by conjecture.

 

[Max Photon]

The disingenuous twoofer "Sizzler" started a thread positing an alternate universe where fantasists are in control. R.Mackey listed five refutations of Twoofer dogma, one of them being extremely pertinent to this thread:

"2. Video clearly shows that at the onset of failure, perimeter columns buckled inward, precipitating the collapse. This requires structural connections to remain intact rather than be blasted apart. No one has even proposed any way to replicate this with explosives."

What do the faux "engineers" have to say?

No one has even proposed any way to replicate this with explosives.

I have proposed a way to replicate this with deliberate heat-weakening.

 

[bofors]

That thing is attached to the hat truss which is a very rigid thing that falls, however if the core fails first I believe it is still consistent with the outside behaviour.

Are there any post collapse pictures of the North tower hat truss? This appears to be a critical element of NIST's proposed collapse initiation scenario.

 

[bofors]

We have seen the west side of WTC 1 with smoke ejections along the entire 98th floor appearing simultaneously.

The smoke ejections along the 98th floor west face do not favor the south side of the building over the north side.

If the ejections along this line are taken to mean that the perimeter gives along this line at the moment we see the ejections, then the north side of the west face gives at about the same time the south side gives.

The smoke ejections along the west face don't suggest hinging towards the south.

Exactly:

The other thing I think we can say is that, if this was do to the building tilting, the ejections would not be so sharply localized. We should also expect more smoke for to emerge from the North face in response to a South hinge, this is not observed.

 

[Apollo20]

Think before you slur!

Rwguinn:

Just this morning you told realcddeal that: "You are now throwing out stupid--if not moronic-- ideas. The antenna did not drop first. Only an idiot will believe that."

Well, rwguinn, please remember that the well respected publication CIVIL ENGINEERING gave, (in Volume 72, page 40), one of the first professionally based assessments of exactly how WTC 1 started to collapse:

"At 10:28:31 A.M. EDT, WTC 1 began to collapse. Future review of videotapes of the event will reveal that the television transmission tower on top of the structure began to move downward and laterally slightly before movement was evident at the exterior wall. This suggests that collapse began with one or more failures in the central core area of the building."

So, rwguinn, I think you owe RealCDdeal an apology,...after all are you not meant to be a CIVIL engineer.... so, PLEASE, live up to that title and BE CIVIL!

 

[R.Mackey]

The key words, of course, being "one of the first." Subsequent analysis that considered additional angles of video proved that the initial antenna "downward motion" is in fact an illusion, created by tilting of the upper block.

rwguinn is correct.

 

[bofors]

On the other hand Nist suggests that the floor connections were so weak (700 bolts/floor) that they just suddenly sheared off allowing 6-11 lower floors of the upper block to drop down on an intact floor below.

This leads to one of the prime reasons why the gravity driven collapse theory is not credible.

If the floors were so easily sheered off, then the tower cores should have substantially remained.

More clearly:

(1) Once relieved of the floors, the relative "safety factor" of a free standing core must have been massive.

(2) Since the cores are essentially hollow, these is no possible mechanism of progressive core collapse.

 

[rwguinn]

The key words, of course, being "one of the first." Subsequent analysis that considered additional angles of video proved that the initial antenna "downward motion" is in fact an illusion, created by tilting of the upper block.

rwguinn is correct.

I keep wondering, how it is that anyone can take preliminary data to defend "troof", even when he knows that it has been superceded by further review and evaluation, and that corrections have been issued.

When others who chose to use that preliminary data as troof (despite knowing that it is fraudulent) are rightfully called frauds, some nutjobs still use it to push their agenda...

 

[bofors]

I keep wondering, how it is that anyone can take preliminary data to defend "troof", even when he knows that it has been superceded by further review and evaluation, and that corrections have been issued.

When others who chose to use that preliminary data as troof (despite knowing that it is fraudulent) are rightfully called frauds, some nutjobs still use it to push their agenda...

I keep wondering why people who claim to have science and evidence on their side of this argument find it necessary to use derogatory words like "troof" and "nutjobs" to make their points.

If you are serious about debunking the demolition theory, why don't you start answering my questions instead of posting crap like this?

 

[Furcifer]

In my view there is an early implosion in the upper block that pulls it together followed by an internal explosion that blows out debris, dust and smoke through the windows between intact columns.

Implosion? Care to follow up on what caused said implosion? I know of nothing on this earth that can cause an implosion such as you describe here.

 

[R.Mackey]

I suppose on review, vis-a-vis rwguinn's post, Dr. Greening is merely stating that someone other than an idiot could believe incorrectly that the antenna dropped first. His evidence is that some authors, presumably not idiots, believed it to be true until receiving better data.

That's reasonable.

Technically I think the claim should be revised to "only idiots and the uninformed believe that the antenna dropped first," but this is a minor adjustment.

Sorry for the confusion.

 

[rwguinn]

I suppose on review, vis-a-vis rwguinn's post, Dr. Greening is merely stating that someone other than an idiot could believe incorrectly that the antenna dropped first. His evidence is that some authors, presumably not idiots, believed it to be true until receiving better data.

That's reasonable.

Technically I think the claim should be revised to "only idiots and the uninformed believe that the antenna dropped first," but this is a minor adjustment.

Sorry for the confusion.

I will accept that correction, but I think the word "intentionally" must be inserted in front of "Uninformed", immediately after "the".

ETA: However, Apollo20 is intentionally misrepresenting my stand. The views were revised on reciept of better data. The better data has been available for something like 7 years.
Anyone who refuses to admit that better data exists,despite having had it spoon-fed to him, is an idiot.

 

[Heiwa]

This leads to one of the prime reasons why the gravity driven collapse theory is not credible.

If the floors were so easily sheered off, then the tower cores should have substantially remained.

More clearly:

(1) Once relieved of the floors, the relative "safety factor" of a free standing core must have been massive.

(2) Since the cores are essentially hollow, these is no possible mechanism of progressive core collapse.

It would appear that the 47 core columns + spandrels (beams) structure was very strong, i.e. at every floor level the very solid vertical core steel columns were connected to one another by horizontal steel beams at 0, 90, 180 and 270°s. If one core column failed, the horizontal beams (at every level) would easily transfer its load (as shear) to the adjacent 2, 3 or 4 core columns, depending on location (corner, outside, inside the core). On the outside of this core the floor trusses were bolted to the beams giving additional support to the corner/outside core columns. The other ends of the floor trusses were evidently bolted to the perimeter wall columns.

Inside the core (about 600 m² total) there were, apart from entrance halls and toilets (no furniture) many vertical openings for lifts and pipe/cable and ventilation trunks. And the escape stairways! Any jet fuel on any floor would just flow down through these vertical shafts. Generally speaking there was very little that could burn inside the core structure!

Outside the core structure area and inside the perimeter walls there were offices - width 10-20 meters - so that most office workers could see a window and look out. Evidently there was not much furniture there to burn.

Most of the space was just air. Everywhere. Uniform density 180 kgs/m3.

Nist suggests that bolted floors dropped down but these floors are all outside the core structure. Nist does not advise where the 700 bolts sheared off - at the perimeter walls - total 250 meters (500 bolts) - or at the core - 100 meters (200 bolts).

The bolts were only sized to transmit the local load on the floor to the columns. The columns carried all the load above it. Thus the bolts were much weaker than the columns.

Say that all bolts at one perimeter wall fail and the floor falls down inside that wall. Result? The floor slopes and all lose items on it slide outside. Then the lose floor end hits the floor below. End of local collapse.

Why would then the inner bolts at the core then fail? Anyway, the core was not supported by the floors on the outside.

So you are 100% right. The core was massively strong and could never collapse due to some local gravity collapse of floors outside of it.

The Nist explanations are just a hotch potch of nonsense. This is a problem to be resolved.

 

[Furcifer]

The other ends of the floor trusses were evidently bolted to the perimeter wall columns.

No.

 

[Good Lt]

Inside the core (about 600 m² total) there were, apart from entrance halls and toilets (no furniture) many vertical openings for lifts and pipe/cable and ventilation trunks. And the escape stairways! Any jet fuel on any floor would just flow down through these vertical shafts. Generally speaking there was very little that could burn inside the core structure!

Your opinion is not evidence of anything. Please provide evidence supporting this claim.

Outside the core structure area and inside the perimeter walls there were offices - width 10-20 meters - so that most office workers could see a window and look out. Evidently there was not much furniture there to burn.

Your opinion is not evidence of anything. Please provide evidence supporting this claim.

Say that all bolts at one perimeter wall fail and the floor falls down inside that wall. Result? The floor slopes and all lose items on it slide outside. Then the lose floor end hits the floor below. End of local collapse.

A hypothetical created by you is not evidence of anything. Please provide evidence supporting this claim.

 

[Furcifer]

Say that all bolts at one perimeter wall fail and the floor falls down inside that wall. Result? The floor slopes and all lose items on it slide outside. Then the lose floor end hits the floor below. End of local collapse.

No.

Hint: hidden in NCSTAR there's an actual picture of this connection. Please look at it.