False Narrative: "North Tower Antenna Dropped Before Roof Line"

[john.phil]

First of all, the deformed shape is because of the floor load that simulation

I'm clearly talking about the mesh. Although, the deformed shape shows the mesh is really coarse.

secondly, this model is the SAP2000 model that was used, I believe in the Silverstein case

Please, provide a link to the model.

You seriously thought that I produced a 110 storey model of the North Tower in SAP2000 back in 2004

No. I thought you produced a 2024 model of just the top of the building. For 2004 standards, the mesh is still not as good as it could have been if more time was invested in it. My post is in the context of 2024.

 

[gerrycan]

Clearly, it wasn't the antenna that overloaded the core columns, it was the weight of the unsupported parts hanging off the hat truss, which increased steadily as the facade buckled.

Can you please explain how, as the core columns fail, the antenna tower drops, while the rest of the top of the building stays suspended in place in a Wile E. Coyote moment?

Spoiler: Wile E. Coyote clip

Source: https://www.youtube.com/watch?v=Gq_bjaI0NTo

Agree, there's no way the antenna could ever do that and of course nobody is suggesting that, but it does drop down initially as FEMA noted. So logically the core was overloaded and the weakest columns deformed first, which are under the antenna module IMO.

 

[gerrycan]

I'm clearly talking about the mesh. Although, the deformed shape shows the mesh is really coarse.


Please, provide a link to the model.


No. I thought you produced a 2024 model of just the top of the building. For 2004 standards, the mesh is still not as good as it could have been if more time was invested in it. My post is in the context of 2024.

Sorry John - your comment was quite clear and if you had any idea about SAP2000 you'd have noted it is only showing a non extruded version of a model that could be extruded to look as realistic as anyone wants it to - beyond any processing power i have though.

EDIT - I much prefer the way that Mendel is approaching this, and actually thinking about the topic, and not trying to personally insult, but make his case and scrutinise the structure, kudos to you for that Mendel.

Your comment though - classic.

 

[Mendel]

this model is the SAP2000 model that was used, I believe in the Silverstein case, and quite possibly by NIST - I have checked the elements in it and they are exact to the drawings, also from NIST.

You didn't realise whos model it was or who did it, or just how accurate the elements in it are.

NIST NCSTAR 1-6:

 

[gerrycan]

Please, provide a link to the model.

You know what, for that comment you made about it, before you realised who had actually made it - I sent it to Mick in email a while bvack - you go ask him for it.

 

[Mendel]

EDIT - I much prefer the way that Mendel is approaching this, and actually thinking about the topic, and not trying to personally insult, but make his case and scrutinise the structure, kudos to you for that Mendel.

You've not adressed my main criticism sufficiently.
I'm simply opening a second avenue of critique, while @john.phil opens up a third. They stand beside each other, not against. Please do not try to cherry-pick the criticisms you acknowledge.

 

[John J.]

How relevant is any of this?

Relevant enough for someone to have started a thread here about it and for people to respond to the topic, and also relevant enough for FEMA to have referred to it in their report.

I meant, how relevant is your raising of your interpretation of your video to an understanding of what happened to the Twin Towers on September 11th 2001?

Our understanding of what happened post-impact is, and always will be, incomplete.
We do not have sufficient knowledge to model precisely what happened. There are far too many factors, too many variables.

For the sake of argument, let's say we found undisputed evidence the antenna dropped before the bulk of the roof.
We might conclude,
(1) There was an error in the generally accepted account of what happened, which is entirely possible.
(2) This might be due to a failure of the structures immediately supporting the antenna: maybe localised temperatures were higher immediately under the antenna, combined with the additional load that the antenna represented.
(3) Or, in the absolute absence of any other evidence or plausible motive, bad men did it (but not Al Qaeda).

 

[gerrycan]

NIST NCSTAR 1-6:
View attachment 73400

Agree with this yes. Nobody showed the failure in any analysis as per that anenna drop. I'm not sure wha point you're making to be honest though. I am sure they COULD have made up shell elements or however they'd choose to model the truss, but the complexity that would bring would be hige and at that time put the thing way beyond a reasonable run time for any serious simulation they might have waned to run, making it impracticle.

I know they had that issue with the floor model, and so omitted srap anchors, shear studs Vertical and horizontal, and rebar etc in that because of processing limitations that NISt had at that time.

I could look out the splices specific to that column row on the truss if it helps. Here's a couple of typical examples of the connections around 107

 

[gerrycan]

I meant, how relevant is your raising of your interpretation of your video to an understanding of what happened to the Twin Towers on September 11th 2001?

John considering your comment, I don't think it's relevant at all in our exchange, with respect.

 

[Mendel]

Agree, there's no way the antenna could ever do that and of course nobody is suggesting that, but it does drop down initially as FEMA noted. So logically the core was overloaded and the weakest columns deformed first, which are under the antenna module IMO.

You don't seem to get my concern.

If I put a load on a weak support, and that load exerts a force that causes the support to break, then the failure of the support immediately causes the force to start moving [the load] downward.

So if it wasn't the transmission tower that caused the overload, but rather the hat truss and everything attached to it, shouldn't the whole hat truss including the building parts attached to it start moving downwards as soon as the core fails?

How does your model explain that the failure of the core moves only the transmission tower, and not the whole truss?

(I still maintain that this is not what happened, and you haven't provided sufficient proof of it.)

 

[gerrycan]

I don't want to post the links to the whole drawing book set here, I got told it broke policy,

If there's somewhere else I could do that I am happy to, and I know my way around them fairly well.

The outrigger truss detail is in book 9 i believe

 

[gerrycan]

You don't seem to get my concern.

If I put a load on a weak support, and that load exerts a force that causes the support to break, then the failure of the support immediately causes the force to start moving downward.

So if it wasn't the transmission tower that caused the overload, but rather the hat truss and everything attached to it, shouldn't the whole hat truss including the building parts attached to it start moving downwards as soon as the core fails?

How does your model explain that the failure of the core moves only the transmission tower, and not the whole truss?

(I still maintain that this is not what happened, and you haven't provided sufficient proof of it.)

Within the official story, I believe the observed downward movement of the antenna indicates that the core structure was already overloaded but was able to pass that overstress to the perimeters via the hat truss, until that load path was compromised, at which point the weakest cores deformed almost at once.

EDIT sorry I meant to add, that the floors and the offloaded perimeter columns on the North face do not move initially, so I dont believe the whole truss failed at once for that reason - I believe the core failed initially, as did FEMA

 

[gerrycan]

"So if it wasn't the transmission tower that caused the overload, but rather the hat truss and everything attached to it, shouldn't the whole hat truss including the building parts attached to it start moving downwards as soon as the core fails?"

I didn't say I thought the hat truss caused the failure - I actually believe that it prevented earlier failure and overloaded the weakest cores when it gave in, and could no longer share overstress from the cores to the perimeters.

 

[Mendel]

I'm not sure what point you're making to be honest though.

Paraphrased:

@john.phil : your model is not good enough to analyse what happened

@gerrycan : that model was good enough for NIST

NIST : our model wasn't good enough, so we checked the action of the hat truss manually

What you're claiming requires an understanding of how the hat truss behaves as the load shifts in a very short time, and NIST's model of the hat truss isn't detailed enough to capture that accurately.

NIST did not care how the hat truss flexed as this occurred, they were merely concerned with how it would behave globally, and came away convinced that the simplifications they made had no global impact (the hat truss wouldn't break or buckle overmuch etc.).

 

[gerrycan]

Here are the core details for comparison, 501 being the most massive, at the corner, and the others less so, nearer the centre of the group of 47. They were significantly weaker below the antenna module.

 

[Mendel]

I didn't say I thought the hat truss caused the failure - I actually believe that it prevented earlier failure and overloaded the weakest cores when it gave in, and could no longer share overstress from the cores to the perimeters.

That makes no sense to me. What caused the cores to be overstressed, if not the hat truss transferring load from the perimeter to the core (and not the other way around)?

 

[Mendel]

Do you agree or disagree?

1) The transmission tower ("antenna") moved separately from the hat truss?

2) The hat truss moved separately from the top of the building?

I believe you have to agree to at least one of the statements, or your claim can't stand.

 

[gerrycan]

Paraphrased:

@john.phil : your model is not good enough to analyse what happened

@gerrycan : that model was good enough for NIST

NIST : our model wasn't good enough, so we checked the action of the hat truss manually

What you're claiming requires an understanding of how the hat truss behaves as the load shifts in a very short time, and NIST's model of the hat truss isn't detailed enough to capture that accurately.

NIST did not care how the hat truss flexed as this occurred, they were merely concerned with how it would behave globally, and came away convinced that the simplifications they made had no global impact (the hat truss wouldn't break or buckle overmuch etc.).

Okay - I posted the model to show the hat truss connections to the perimeter to Bentham, that had they failed as the antenna dropped, the offloaded perimeters would have distorted.

I do see column 155 doing that, slightly before the antenna moves.

As for the model - only posted to show the connection to the perimeters though, which is why i said i could recolour them to make it more distinct.

I don't think he model could illustrate the antenna failure, and wasn't trying to say that it could. I see what you were getting at now though. But no - That model wouldn't show that, but I could get it to show the relative shortening in the cores I guess which would give an idea of how weak/strong they were wrt each other.

The full height model lacks floors, apart from MER and beamed floor levels. So only really any good fopr demand/capacity ratios and load paths.

 

[gerrycan]

Do you agree or disagree?

1) The transmission tower ("antenna") moved separately from the hat truss?

2) The hat truss moved separately from the top of the building?

I believe you have to agree to at least one of the statements, or your claim can't stand.

#1 can't happen unless it is only lateral movement because the hat truss supported the antenna module - if it helps, I would say that not the whole truss failed, but some would have to for the downward movement of the antenna to happen.

for #2, straight no

 

[gerrycan]

That makes no sense to me. What caused the cores to be overstressed, if not the hat truss transferring load from the perimeter to the core (and not the other way around)?

Well this is the question. Something made the antenna move down, and something IMO (and FEMAs) caused the core to fail first, indicated by the antenna moving independently of the roofline, as they pointed out.

 

[gerrycan]

Sorry, but I can't.

I tried to find the right words, so to not incur the risk of gratuitously offending you, and to not risk falling into the trap of lack of constructivism, but I'm no Eric Weinstein vs Terrence Howard. So, please excuse my French, but this has to be one of the crappiest meshes I have seen.

View attachment 73390
View attachment 73389

I'm only commenting because, based on your youtube channel history and the passion you show in some of your videos, you've been obsessed with this for over 11 years; however, your modelling skills are stuck at the first month pressing random buttons in FEA software. It seems to me that you've got a case of Dunning-Kruger effect in civil engineering.

There is no other way of putting this, but the reality is that the collapse of the towers is beyond your knowledge, skillset and technical level by orders of magnitude. This is a multidisciplinary problem between civil engineers, mechanical engineers, and FEA specialists from both backgrounds, actively collaborating with each other, and with access to more physical information about the event than you will ever have from your armchair across the globe. This is a job easily in the tens of thousands of collective professional hours.

No simplified model will ever provide a definitive conclusion. Moreover, no complex model on its own will do it either without proper calibration against known actual data from the buildings, from the collapse, lab tests, physical models, and independent replication.

No unchecked/unverified work will do. But you are on your own without peer review. So, this is a nonstarter. If your objective was to learn about the subject, without any bias, out of passion for the field of engineering, then you would find plenty of people willing to help you acquire the skills. But the only thing you are achieving is using your own bias to press buttons which produce results that convince you more of your own bias, and your non-technical audience will cheer you along the way, passionately pushing you deeper into the +12th year.

I know you are familiar with the NIST report. I mention it to serve as a reality check against the model you have produced so far. I understand you are going for the Reduced Global Model on page 67, but that model was not born first out of thin air, it was part of an intricate process, and unlike yours, that model does not exist on its own, it requires the detailed shell models, all the analyses carried out with them and independent verification:

Source for the images below: https://www.nist.gov/system/files/documents/2017/04/28/June2004BaselineStructuralAnalysisPrint.pdf

View attachment 73397
View attachment 73395
View attachment 73398

"but this has to be one of the crappiest meshes I have seen." coming from a "senior member" I simply have to respond to, as it clearly was intended to be offensive.......
wrt material assignment colours - same model as you just said was "one of the crappiest you'd ever seen" - Zoom in on this jpg, which is much higher quality in its original bmp format which won't upload...

And here's the hat truss extruded, again same model as you said was "one of the crappiest" you'd ever seen....

Again, zoom in on the detail.
You clearly did try to slag off a model and a member here with no other motivation than to offend, which is why I am responding. This response is not as off topic as your attempt to offend, which backfired spectacularly. SAME MODEL as you slagged off - Look nicer now John ??

 

[gerrycan]

There is no other way of putting this, but the reality is that the collapse of the towers is beyond your knowledge, skillset and technical level by orders of magnitude. This is a multidisciplinary problem between civil engineers, mechanical engineers, and FEA specialists from both backgrounds, actively collaborating with each other, and with access to more physical information about the event than you will ever have from your armchair across the globe. This is a job easily in the tens of thousands of collective professional hours.

The first time I started a thread on here John, may be of interest to you...... I remember getting a similar reaction, but not quite as barbed as yours. Turned out we were correct, and it remains undebunked. You have no idea of my skillset or what I do or am qualified in, yet you condascend and insult so easily. That deserves a proper response, and you need a lesson.

This antenna drop, prior to the movement that has been discussed in this thread and elsewhere, but noted by FEMA in their report is indicative of mass being removed from below the point of impact into this tower. I chose my words very carefully there. Keep in mind that on the basis of a couple of short captures from a FEA you just mistakenly slagged off a model that was the result of exactly that which you said it was the opposite to - ie a highly skilled team of professionals with a wide range of discipline specialities with access to all the data they needed and a huge amount of time and money with which to achieve their aim.

You clearly showed your agenda and lack of knowledge in the subject by your reaction to that short video capture. What you said was indeed a personal attack, and I am taking that personally.

I imagine you're red in the face. If not, you really should be as a senior member here.

 

[john.phil]

showing a non extruded version of a model

My comment is on the mesh, not the wireframe representation.

And here's the hat truss extruded, again same model as you said was "one of the crappiest" you'd ever seen....

Again, zoom in on the detail.
You clearly did try to slag off a model and a member here with no other motivation than to offend, which is why I am responding. This response is not as off topic as your attempt to offend, which backfired spectacularly. SAME MODEL as you slagged off - Look nicer now John ??

Thanks, this gives better context on the size and detail in the model, but it's just the geometry model displaying the cross sections applied to the structural components. Can you please show the mesh instead, as that is what the "crappiest" quote is referencing?

I tried to not offend you, read my post again, as I made an effort not to.

I'd suggest one of the senior members deletes your comment for you and saves your blushes.

No need to delete it at all, as my initial comment is based on the assumption that you authored the model, and that's because you mentioned you were going to make alterations. And although this has been clarified now, the remainder of my post is still relevant, as it addresses the belief that this model can be used out of its original scope and intent, by someone who's neither SQEP (Suitably Qualified Experienced Person), nor familiar with the model, and without a checker and an ITA (Independent Technical Authority), to produce meaningless results intended to prove a certain bias, and which are going to be cheered by a non-technical audience, so you can keep obsessing with it for another year.

 

[gerrycan]

My comment is on the mesh, not the wireframe representation.


Thanks, this gives better context on the size and detail in the model, but it's just the geometry model displaying the cross sections applied to the structural components. Can you please show the mesh instead, as that is what the "crappiest" quote is referencing?

I tried to not offend you, read my post again, as I made an effort not to.


No need to delete it at all, as my initial comment is based on the assumption that you authored the model, and that's because you mentioned you were going to make alterations. And although this has been clarified now, the remainder of my post is still relevant, as it addresses the belief that this model can be used out of its original scope and intent, by someone who's neither SQEP (Suitably Qualified Experienced Person), nor familiar with the model, and without a checker and an ITA (Independent Technical Authority), to produce meaningless results intended to prove a certain bias, and which are going to be cheered by a non-technical audience, so you can keep obsessing with it for another year.

Hang on, I don't quite understand. You said the mesh was "the crappiest you'd ever seen" on the basis of what was originally posted. Do you stand by that assertion that you were apparently able to make on the basis of a short video capture alone or not ?

I wonder if you could maybe go into detail, maybe elsewhere about how you ascertained that level of knowledge about a FE model that you didn't know the origin of, and frankly still don't on the basis of that short video capture.

ADD i note that you also somewhat confused about what exactly a shell ELEMENT is.
Tell me, how did you ascertain that level of detail from that video, ?

 

[Mendel]

The first time I started a thread on here John, may be of interest to you...... I remember getting a similar reaction, but not quite as barbed as yours. Turned out we were correct, and it remains undebunked

except there are 4 independent analyses of the WTC7 collapse saying much the same as NIST
https://www.metabunk.org/threads/critical-errors-and-omissions-in-wtc7-report-uncovered.2332/

your argumentative strategy then is the same as now:
• trying to argue from authority without establishing any (others might call that "assuming a patronizing tone")
• evading requests for evidence
• focusing on "NIST is wrong" instead of providing an alternate explanation

The same happened here.
You have
• not provided evidence for the transmission tower moving independently
• not given a sequence that would lead to it moving independently
• admitted it can't move independently
• misrepresented FEMA's statement

I am not going to argue with you for 20 pages on that level, even if you genuinely think your claim hasn't been debunked.

 

[Mendel]

Zoom in on this jpg, which is much higher quality in its original bmp format which won't upload...

convert bmp to png to preserve quality while reducing file size

 

[gerrycan]

except there are 4 independent analyses of the WTC7 collapse yaying much the same as NIST
https://www.metabunk.org/threads/critical-errors-and-omissions-in-wtc7-report-uncovered.2332/

your argumentative strategy then is the same as now:
• trying to argue from authority without establishing any (others might call that "assuming a patronizing tone")
• evading requests for evidence
• focusing on "NIST is wrong" instead of providing an alternate explanation

The same happened here.
You have
• not provided evidence for the transmission tower moving independently
• not given a sequence that would lead to it moving independently
• admitted it can't move independently
• misrepresented FEMA's statement

I am not going to argue with you for 20 pages on that level, even if you genuinely think your claim hasn't been debunked.

No problem Mendel, and thanks for yhe decent exchange regardless.

If you or anyone else can find footage that shows any movement in any of the faces of the North Tower that syncs up with the 3-4 ft antenna drop then stop jolt, I guess that would get to the bottom of it.

I had initially looked at the south wall inward bowing being a possible root cause for it, but it just doesn't play out in the load paths. The vast amounts of studded framing embedded in the slab especially in the core bracing through the entire system doesn't allow it.

Interesting that you guys reckon you debunked FEMA

 

[john.phil]

Hang on, I don't quite understand. You said the mesh was "the crappiest you'd ever seen" on the basis of what was originally posted. Do you stand by that assertion that you were apparently able to make on the basis of a short video capture alone or not ?

The video shows the mesh, and it is really coarse, or as I bluntly put it, "among the crappiest I have seen", and that's in the context of 2024 standards and for a model comprised of only the top section of the building (i.e. no excuse for it in 2024, because there is greater computational capability nowadays, which didn't exist back then, when coarse mesh was the way forward for making complex models feasible, but with caveats, assumptions, additional assessments and a comprehensive sensitivity analysis, so it was not a free lunch).

I have been asking you repeatedly to show the mesh (and you still haven't), because you replied to my comment about the mesh by first mentioning "extrusion", which is related to the geometry, not the mesh, and later showing the geometry instead. You completely misunderstood what the word "mesh" means in the context of FEA, and immediately replied with:

non extruded version of a model that could be extruded to look as realistic

So, at that point, it became clear to me that you don't even know what "mesh" means, also because you believe it is possible to improve the mesh by simply pressing a button that shows a realistic view. And that is the biggest red flag for anyone planning on carrying out FEA, because FEA is almost all about the mesh. For any beginner in FEA, there is no possibility of confounding mesh with the geometry, as it is FEA 101.

Could you please show the mesh?

Tell me, how did you ascertain that level of detail from that video, ?

From the elements' relative sizes to the structural spacing along the edges, the way the mesh expands from the edges to make the model coarse on purpose, and especially the deformed shape, which independently shows the mesh is coarse (i.e. even if the mesh was not visible, just by looking at the deformed shape, it is very obvious the mesh is coarse, which prompted me to say "I can't ignore the deformed view" when you requested us not to pay attention to it).

 

[gerrycan]

The video shows the mesh, and it is really coarse, or as I bluntly put it, "among the crappiest I have seen", and that's in the context of 2024 standards and for a model comprised of only the top section of the building (i.e. no excuse for it in 2024, because there is greater computational capability nowadays, which didn't exist back then, when coarse mesh was the way forward for making complex models feasible, but with caveats, assumptions, additional assessments and a comprehensive sensitivity analysis, so it was not a free lunch).

I have been asking you repeatedly to show the mesh (and you still haven't), because you replied to my comment about the mesh by first mentioning "extrusion", which is related to the geometry, not the mesh, and later showing the geometry instead. You completely misunderstood what the word "mesh" means in the context of FEA, and immediately replied with:

So, at that point, it became clear to me that you don't even know what "mesh" means, also because you believe it is possible to improve the mesh by simply pressing a button that shows a realistic view. And that is the biggest red flag for anyone planning on carrying out FEA, because FEA is almost all about the mesh. For any beginner in FEA, there is no possibility of confounding mesh with the geometry, as it is FEA 101.

Could you please show the mesh?


From the elements' relative sizes to the structural spacing along the edges, the way the mesh expands from the edges to make the model coarse on purpose, and especially the deformed shape, which independently shows the mesh is coarse (i.e. even if the mesh was not visible, just by looking at the deformed shape, it is very obvious the mesh is coarse, which prompted me to say "I can't ignore the deformed view" when you requested us not to pay attention to it).

You're making a lot of presumptions there. About me, and about the model. Too many to address here, but suffice to say, I understand what mesh is in the context of FEA.

First you said that the model showed how little I knew about FEA and how bad i was at it, and how it couldnt show anything at all and how the deformed shape was something you could not ignore, it was so bad.

I don't think you can ascertain what you are trying to from that video at all, which is showing deflection in elements only. I'm hesiant to go back in and spend time on model oputputs for you to sit and try to pick through the bones of it quite honestly. I am not the most knowledgable on FEA, and never claimed to be, but I know the basics of it.

You are intent and very keen to try and discredit me on the basis of one video captrue of a wire frame model that I set for the quickest refresh rate I could get, and your agenda is clear here, and you gave that away with your first comment to me.

My idea of mesh, very roughly would be that it is the definition of the model elements. Finer mesh, more accuracy, more run time. Given that this model has only MER beamed floor s present, I think it would probably be better to describe what this particular model is intended to ascertain through simulation with that in mind.

I'd suggest its intended use would be mainly demand capacity ratios in the columns, and to define load path comparisons between an undamaged and a damaged structure. Using beam and column elements.

Do you agree with that, and tell me out of interest - can you tell very much about this capture here of a different model and how the mesh size may be very different in it compared to the one you saw previously.


Source: https://youtu.be/7J9YSD_AkxA


Dio you think the mesh here is finer or coarser than the previous model you viewed ?

ADD Maybe I should have used this pic here originally to illustrate how the elements connect, might have saved all this "i know more than you about FEA" nonsense. BTW, I don''t think you do. And as I said, I never made ANY claim whatsoever about any FEA abilities at all, apart from suggesting that I may go in and change the element colours to beter illustrate my point.

Do you see what I am getting at wrt how this debate came to this point - you trying to get someone you said a while ago was a total learner who didn't have much of a clue and had produced the "crappiest looking mesh" you'd seen, to go and edit a FE model for you now, and tell you it's properties.

You see how we got from there to here yet John ?

 

[gerrycan]

I have an idea that might help us keep on topic here. Instead of me getting ordered around to go get mesh illustrative captures, why dont we discuss the actual connecions that we are talking about first ?

Link to page provided - https://archive.org/details/WTCI000031L/Drawing Book 9/WTCI-000030-L/page/n2/mode/1up

 

[gerrycan]

you really need 2 different view angles to support that claim
see post #1
repeating the claim does not improve the evidence

No I don't, and where did you get that from ?
The antenna moving DOWN is undeniable. For this to be movement to the South, ie the antenna falling backward, would require MORE movement in it to produce the same observable drop.
For the record, here is what FEMA said again...

And for absolute clarity, here is a slowed down version of the movement in the North Tower that you and the others on this thread missed, which is what FEMA were referring to.
If you or anypone else still cannot see that FEMA were EXACTLY correct then you need to state that clearly, and make your case.

The antenna moves downward, then laterally prior to the perimeter moving - which is what FEMA said and what this thread claims to be a "false narrative"

 

[JMartJr]

The antenna moves downward, then laterally

Yes.

prior to the perimeter moving

To say that, you need to see around the whole perimeter. If you only have one angle, all you can say is "...before this one part of the perimeter that is visible in this one angle moved."

 

[gerrycan]

Yes.


To say that, you need to see around the whole perimeter. If you only have one angle, all you can say is "...before this one part of the perimeter that is visible in this one angle moved."

We agree that the antenna moves independently of the roofline initially -that is a start.

So if the observed DOWNWARD movement in the antenna was actually the antenna failing to the South, that would require MORE movement in the antenna than a straight down drop does. Agree ?
I don't get what is difficult to grasp about this.

 

[gerrycan]

I have provided earlier the structural drawing book specific to the hat truss, which held the antenna module onto which the antenna was attached. You can see that as well as the corner connections from truss to perimeters, core columns 504, 505, 1004, 1005, and column rows 700 and 800 from non perimeter cores are what is holding the hat truss. The connections from the outer cores to the perimeters can also be seen clearly.

I can see why anyone supporting the official narrative wouln't want to admit the reality of this, especially if they'd started a thread claiming to debunk FEMA, who clearly did observe these events from various angles, without a closer look at the actual video which confirms FEMAs claim.

The narrative that the antenna moved straight down and laterally before any observable movement in the roofline is NOT false, as claimed.

 

[Mendel]

The antenna moving DOWN is undeniable. For this to be movement to the South, ie the antenna falling backward, would require MORE movement in it to produce the same observable drop.
For the record, here is what FEMA said again...

The transmission tower moves before the northern roofline moves significantly. In post #99, you agreed with me and FEMA that the transmission tower was firmly attached to the hat truss and could not move independently of it. That indicates that the hat truss (and with it the upper block) moved in a way that affected the northern roofline very little. This is achieved by a southward tilting motion, as evidenced by east or west views of the collapse. To enable this tilting motion, 1. the southern facade must fail; 2. core columns must fail: "This suggests that collapse began with one or more failures in the central core area of the building", as FEMA notes in the sentence after the portion you highlighted.

The fact that the roofline cannot be seen to move in the video does not imply that the roofline did not move at all, as the video is not precise enough to make that determination.

 

[gerrycan]

The transmission tower moves before the northern roofline moves significantly. In post #99, you agreed with me and FEMA that the transmission tower was firmly attached to the hat truss and could not move independently of it. That indicates that the hat truss (and with it the upper block) moved in a way that affected the northern roofline very little. This is achieved by a southward tilting motion, as evidenced by east or west views of the collapse. To enable this tilting motion, 1. the southern facade must fail; 2. core columns must fail: "This suggests that collapse began with one or more failures in the central core area of the building", as FEMA notes in the sentence after the portion you highlighted.

The fact that the roofline cannot be seen to move in the video does not imply that the roofline did not move at all, as the video is not precise enough to make that determination.

This sharp drop observed in the antenna happens in less than 1/10th of a second.

What I asked you was if you agree that if that drop was the antenna moving South with the tilt of the building (which hasn't yet started in the video) then that means that the antenna would be moving MORE than if it were falling straight down.

Do you have any idea how much of a tilt would need to happen in the antenna for a drop of that magnitude to be observable ?

It is far far more than 4 feet.

The fact is that you guys started a thread and debunked the wrong bit video. FEMA were talking about events just prior to those you have been discussing thus far in this thread.

You don't get to just staple your attempted debunk for that onto events 2-3 seconds prior.

The claim in this thread has been thoroughly debunked.

 

[gerrycan]

A clear answer to this will clear it up.....

Are the movements annotated in the video I showed you different or the same as the movements you tried to debunk before I joined this thread ?

 

[Mendel]

You don't get to just staple your attempted debunk for that onto events 2-3 seconds prior.

I have asked for evidence of this claim in the very first reply to your original post, but so far you have not provided it. Or did I miss it?

 

[gerrycan]

The fact is that you cannot show that the roofline moved at any place consistent with the antenna because it did not. FEMA would also have found it - they're not that stupid.

Trying to rely on a South tilting movement to cover a 4ft+ drop that took about 1/10s, which you were previously unaware of is ridiculous.

Yeah, you missed it. The antenna would need to move way way more than 4ft to the South to show that observable drop and it would need to do it in around 1/10th of a second, and every agency and every report writer and researcher since 911 happened would need to have missed that somehow.

You are avoiding answering straight and clear questions.
For obvious reasons. Done here until you do.

 

[FatPhil]

Do you have any idea how much of a tilt would need to happen in the antenna for a drop of that magnitude to be observable ?

It is far far more than 4 feet.

Let's just start by saying I'm no fan of measuring tilt in feet - that shows a lack of clarity of thought. Can you knock up a quick sketch with all the relevant dimensions and angles (hint, hint), such that we can at least see if your argument is internally consistent.