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

[Belz...]

I would have expected that the perimeter columns iwo the plane wings were just cut in one location and that the top and bottom parts were bent inwards, but no. All columns were cut in two locations with the bit between missing. If you fake the 'impact' it is easier to cut off the columns at two places each leaving a missing piece - a hole looking like a plane. To cut the column in only one location and then bend the two parts inward is more complicated.

You have no idea how these things work, do you ? You're really just working from your own "common sense" and gut feelings, right ?

Thus the plane was 100% intact after passing the south wall

Non sequitur.

I was stunned. A plane slicing through a wall of steel perimeter columns - like a knife cutting warm butter.

Considering the 767 was torn to twisted shreds by the impact, I'd say you're flat-out, completely, 100%, bat-crazy wrong.

 

[Heiwa]

Considering the 767 was torn to twisted shreds by the impact, I'd say you're flat-out, completely, 100%, bat-crazy wrong.

You must be blind. Look again at all these videos. It takes only 0.2 seconds. You do not need to be an engineer with any certificate for that. Just common sense. The plane ... or whatever it is (why do you believe it is a 767?) ... disappears into the tower through the south wall. No twisted shreads anywhere. Magic. What an impact! The relevant perimeter columns are apparently each cut in two places - the intermediate column piece disappears (seen later). No bending of any column ends. Just plain cuts! The wall just opens up and swallows the plane ... or whatever it is. Plenty people suggest it is bad video trickery. I agree ... and nobody has proven the opposite. It seems NIST just accepts paranormal or magic impacts.

Actually all NIST observed 'facts' of damages are based on videos. No serious accident investigator analyze accidents based on films. You do a proper forensic examination of the real things. NIST missed that too.

 

[T.A.M.]

Ummm...given they couldnt investigate the columns etc until after the collapse, how do you suggest they seperate the steel damaged, twisted, severed, by the collapse, versus that done by the impacts?

I think given the collapse made all comparisons of the steel physical damage before and after useless, video and PHOTOS are the best they had...

TAM

 

[Hokulele]

I thought I heard an argument from incredulity regarding a 767 penetrating the WTC. Is it time for the pieces of straw embedded in telephone poles links and pictures yet?

 

[Heiwa]

Actually, when someone addresses your points, takes the time to look up the references and provides a counter argument, it becomes relevant. It seems far more likely that you're simply uninterested in engaging in an engineering discussion.

I try. Take, e.g. the floor connections to the columns in WTC2. It can only transmit horizontal, axial forces. It cannot transmit any bending. It cannot transmit any shear (except the small weight of furniture on the floor to the columns = negligible ). Therefore it cannot transmit any vertical gravity loads from a perimeter column to a core column as suggested by NIST. This is basic! Do you need more evidence? I expect som basic knowledge of participants in the discussion.

I have explained some other functions of the floors (wind pressure transfer, resist torsion, etc) and concludes that the main function was being a horizontal fire division - not a primary structural part. This is also quite basic. Do you need more evidence.

And then plenty of people query this without any real counter arguments. I am quite disappointed of the quality of the discussion here. Plenty of personal OT comments also! No style. Bad upbringing? Let's keep that outside a serious engineering discussion.

 

[Heiwa]

Ummm...given they couldnt investigate the columns etc until after the collapse, how do you suggest they seperate the steel damaged, twisted, severed, by the collapse, versus that done by the impacts?

I think given the collapse made all comparisons of the steel physical damage before and after useless, video and PHOTOS are the best they had...

TAM

Simple! You sort all the parts of the wreckage including the perimeter columns. Evidently damages from an alleged impact cutting perimeter columns in two places differ completely from damages on perimeter columns due to an alleged gravity global collapse.

 

[The Almond]

I try. Take, e.g. the floor connections to the columns in WTC2. It can only transmit horizontal, axial forces. It cannot transmit any bending.

It doesn't transmit bending, it causes it. Sagging on the floor truss creates an out of plane tensile force causing a positive moment on the beam.

It cannot transmit any shear (except the small weight of furniture on the floor to the columns = negligible ).

The weight of the floor to the columns is not negligible, no matter how much you want it to be. This is reality, deal with it.

Therefore it cannot transmit any vertical gravity loads from a perimeter column to a core column as suggested by NIST.

The hat truss transmitted the gravity loads. Why do you ignore this fact?

This is basic! Do you need more evidence? I expect som basic knowledge of participants in the discussion.

Newton's Bit and I are fully diplomaed engineers, and frankly, we don't spout your nonsense.

I have explained some other functions of the floors (wind pressure transfer, resist torsion, etc) and concludes that the main function was being a horizontal fire division - not a primary structural part.

That's ludicrous.

This is also quite basic. Do you need more evidence.

As I haven't gotten any to date, yes, I'm going to need more evidence.

And then plenty of people query this without any real counter arguments.

Feel free to ignore them in the same way that you ignore people with real counter arguments.

I am quite disappointed of the quality of the discussion here.

You are free to leave at any time.

Plenty of personal OT comments also! No style. Bad upbringing? Let's keep that outside a serious engineering discussion.

In my opinion, we haven't engaged in a serious engineering discussion.

 

[Heiwa]

It doesn't transmit bending, it causes it. Sagging on the floor truss creates an out of plane tensile force causing a positive moment on the beam.

The weight of the floor to the columns is not negligible, no matter how much you want it to be. This is reality, deal with it.

The hat truss transmitted the gravity loads. Why do you ignore this fact?

Newton's Bit and I are fully diplomaed engineers, and frankly, we don't spout your nonsense.

That's ludicrous.

As I haven't gotten any to date, yes, I'm going to need more evidence.

Feel free to ignore them in the same way that you ignore people with real counter arguments.

You are free to leave at any time.

In my opinion, we haven't engaged in a serious engineering discussion.

You say "Sagging on the floor truss creates an out of plane tensile force causing a positive moment on the beam".

Actually it is the weight on the floor truss that creates a saggging bending moment at mid-distance between outer and core walls - tension in the bottom flange, compression in the concrete/plate sandwich you walk on. However this bending moment and its bending stresses are zero at the wall columns.

The weight on the floor 20 kgs/m² is of course negligible compared with the 12.5% of the total weight of the building carried by the outer wall and allegedly re-distributed from the outer wall to the core via the floor - that cannot transfer any bending between itself and the column!!

Sorry - the floors cannot redistribute any gravity loads from the wall to the core as alleged by NIST.

 

[Corsair 115]

Not to put too fine a point on this, Corsair, but some RC aircraft can be flown by either human or autonomous control. They can be flown by human control and then switched to follow pre-planned waypoints sent from the ground control station. If it loses contact with the ground station, it can have an on-board program to cause it to fly to a waypoint within range of the station, or even auto-land itself.

Neat, I didn't know that. I've always seen RC aircraft with the land-bound pilot thumbing the control levers.

These aircraft are still considered to be Remote Control aircraft, even when there is no human-in-the-loop. So your correction of Heiwa is not 100% accurate.

I suppose it comes down to how strictly one wants to define "remote control." I've always thought and heard it in connection to a human controlling a device from a remote location, thus giving rise to the term. If the device is operating without human control, I can't really think of that as remote control.

I suppose it might be time to break out the dictionaries...

 

[Belz...]

You must be blind. Look again at all these videos. It takes only 0.2 seconds. You do not need to be an engineer with any certificate for that. Just common sense.

What IS IT with truthers and common sense ? How can common sense possibly help you understand such a catastrophic, complex, non-common event ?

The plane ... or whatever it is (why do you believe it is a 767?) ... disappears into the tower through the south wall. No twisted shreads anywhere.

Anywhere ? Not even on the nearby rooftops ? Not even that engine that fell in the street ? Not even those human remains they found ? Not even the landing gear ? You must be blind.

No bending of any column ends. Just plain cuts!

Even so, why would you expect them to bend ?

The wall just opens up and swallows the plane ... or whatever it is.

You're either lying or incapable of interpreting videos. The plane punches through the facade. It's going hundreds of miles per hour. What exactly do you expect it to do ?

Plenty people suggest it is bad video trickery.

Why ? Because they can't fathom how high-speed collision works ?

I agree ...

Of course you do. You seem predisposed to believing that.

and nobody has proven the opposite.

Prove the opposite of what ? A crackpot, armchair conjecture from laypeople ?

It seems NIST just accepts paranormal or magic impacts.

Perhaps. Or, maybe, they're actual, professional experts that know what they're talking about and they know more about the physics involved than you ever will, making them far more likely to have the right answer.

Sorry - the floors cannot redistribute any gravity loads from the wall to the core as alleged by NIST.

And why not ? Please show this.

 

[T.A.M.]

Simple! You sort all the parts of the wreckage including the perimeter columns. Evidently damages from an alleged impact cutting perimeter columns in two places differ completely from damages on perimeter columns due to an alleged gravity global collapse.

Really? Please, using your expertese in this field, explain to us how the columns that were damaged by impact plus collapse would differ from columns damaged by just the collapse alone.

If you cannot answer, please refrain from speculating on it?

TAM

 

[Heiwa]

Really? Please, using your expertese in this field, explain to us how the columns that were damaged by impact plus collapse would differ from columns damaged by just the collapse alone.

If you cannot answer, please refrain from speculating on it?

TAM

I thought that was clear from previous observations? At impact sideways the perimeter steel column is allegedly cut or sheared off laterally in two locations by aluminium structure with the steel bit in between being removed inward. The steel column was not cut in one location only with the two ends being bent inward. The surfaces of the cut areas will provide more info how it took place, e.g. if it was a plane or whatever.

When the column collapses due to gravity the excess forces are in the longitudinal direction and the ruptured surfaces will appear completely different.

That is why forensic examination of the core columns was also very important. Did they break due to gravity axial collapse or were they cut off laterally by explosive devices of CD? The ruptured surfaces would clearly indicate which. There are some photos of ruptured core columns where the ruptured surfaces seem to have been subject to heat/cutting = CD.

 

[T.A.M.]

really, the "ruptured surfaces" will look COMPLETELY different. How do you know this? Have you examined steel that was initially cut by impact, but then was also subject to collapse, and compare it to steel that wasnt cut, but also subject to the same collapse? I didn't know you were involved in building collapse investigation? Is this on the side, when you are not engineering...lol

TAM

 

[T.A.M.]

The column "ruptures" that you have mentioned, they wouldnt happen to be the ones we see posted all the time with the welding torch diagonal cut, and the rescueworkers in the foreground, would it?

TAM

 

[twinstead]

So it appears we have another arm-chair expert claiming to see something that all the real experts from around the world have studied, something taught in engineering schools world-wide, and is responsible for changes in building codes simply missed.

God bless the YouTube generation.

 

[Heiwa]

really, the "ruptured surfaces" will look COMPLETELY different. How do you know this? Have you examined steel that was initially cut by impact, but then was also subject to collapse, and compare it to steel that wasnt cut, but also subject to the same collapse? I didn't know you were involved in building collapse investigation? Is this on the side, when you are not engineering...lol

TAM

How do I know this? When plates in ships ruptures we study, apart from the material itself, the ruptured surfaces to find out more. Ruptures due to shear differs from those due to pull, etc. You can actually see in what direction the plate ruptured. Steel samples have been taken from ruptured plates of a certain ship (see my web page) to establish why it ruptured. Some people think the rupture was caused by explosives! Then not only the surface is of interest but also the material itself - it changes due to heat and the explosive rupture, etc. The same methods are used in steel building collapse analysis.

 

[Heiwa]

And why not ? Please show this.

You have not read message #288? Anyway - the floor truss could only transmit the small weight on and of the truss itself to the columns. No substantial gravity load in a perimeter column can be transmitted through the truss to the core column as shear. The truss connections to the column are too weak and the truss itself lacks capability to transfer big shear loads.

Thus gravity load redistribution between perimeter columns is only via the spandrels and that worked nice around the hole in the south wall.

The four functions of the floor were completely different (see earlier message). After the initial damages to WTC2 the structure stood due to its redundancy. Afterwards there was fire. I doubt very much that the fire ruptured any structure further (there is no evidence for that) and that only minor deformations took place. In that case the floor - even if sagged - could still carry out the four functions it was supposed to do ... and no collapse of any kind would ensue.

The major function of the floor was to support the columns sideways. There is no evidence that the heated floors failed to do that. The perimeter was always cooled by fresh air all around - most floor/column connections around the perimeter was intact after impact and the heat could not cause further damage. The spandrels would re-distribute the gravity load. No chance that global collapse could then ensue.

The NIST report is full of guess work and unproven estimates of various parameters, e.g. exaggerated temperatures 30-40 minutes after first impact, and thus very unreliable. Stupid suggestions that the steel would melt are encouraged, etc. All assumptions seem to be arranged to make the global collapse due to heat a possibility that could ensue.

The fire was only due to furniture, office equipment and decorations burning. The jet fuel burnt at once in the fire ball or poured down to the street. So no high temperatures could ensue. And no global collapse could ensue.

 

[Heiwa]

The column "ruptures" that you have mentioned, they wouldnt happen to be the ones we see posted all the time with the welding torch diagonal cut, and the rescueworkers in the foreground, would it?

TAM

Of course not.

 

[Dave Rogers]

The major function of the floor was to support the columns sideways. There is no evidence that the heated floors failed to do that.

There is ample and highly compelling evidence that the floors not only failed to support the columns sideways, but that they actually exerted a lateral force on the columns. Look for some photos of the inward bowing of the exterior columns, then tell me that those columns are adequately laterally supported.

Dave

 

[AZCat]

You say "Sagging on the floor truss creates an out of plane tensile force causing a positive moment on the beam".

Actually it is the weight on the floor truss that creates a saggging bending moment at mid-distance between outer and core walls - tension in the bottom flange, compression in the concrete/plate sandwich you walk on. However this bending moment and its bending stresses are zero at the wall columns.

The weight on the floor 20 kgs/m² is of course negligible compared with the 12.5% of the total weight of the building carried by the outer wall and allegedly re-distributed from the outer wall to the core via the floor - that cannot transfer any bending between itself and the column!!

Sorry - the floors cannot redistribute any gravity loads from the wall to the core as alleged by NIST.

Maybe I'm missing something here, but when the floor trusses begin sagging, doesn't the sag itself make the straight-line distance between the end points of the truss shorter because of the curve of the sag since the length of the truss does not change? This would create a non-axial load on the columns, right?