Merged Freefall is not evidence for Controlled Demolition

[tfk]

I understand the alum can analogy. I question of there was enough debris pushing at the columns of the lower section.... and where would be be pushing?

I think a possibility was that the interior collapse caused the structures in the core when they dropped to pull the lower portions of the moment frame via the beams and girders spanning between the core and the perimeter.

I think this explains the tall vertical kink which appears to be where the girder 44-79 was located.

So I am suggesting it was an INWARD pull by the beams and girders and attached slabs rather than the accumulation of debris pushing outward.

You might be right about this.

But I'm talking about a point in time much later than the formation of the C44-C79 kink.

See here:

These are 3 sequential time steps in NIST's collapse model.

(And, no, I don't think that this is holy writ & infallible.)

The only way that I can think of (now) to distinguish "it just buckled outward" from "it buckled outward from the accumulation of falling debris against the inside of the outer wall" would be by re-running the FEA, and constructing an artificial, thin-wall, infinitely strong "tub" just inside the outer wall, attached to no other component, which would catch all the fallen debris and prevent its load from being transmitted to the outer wall.

There is frankly no particular point to doing this exercise.

But you bring up the exact reason that I think that it happened due to the mechanism I described. The falling debris alone would put a very large inward pull force on the outside walls. From the mechanism you describe, I would fully expect the buckling to be an INWARD buckling.

The buckling shown in NIST's simulation, and much more importantly, as described by the witness, was an OUTWARD buckling of the entire lower wall of the north face. Pretty much as shown in the screen grabs above.

The point of this is that the period of free fall is very likely directly associated with the formation of this low kink. As soon as the (approximately 8 story) 3 knuckle kink forms, the external north walls ability to support load goes to near zero. And one would fully expect a near free fall collapse.

As I've stated previously, the 8 - 10 story collapse that had already happened across the entire core, at the same elevation as this external kink, supports "building on stilts" interpretation of events. And these images show the buckling of the stilts.

 

[tfk]

BTW, it is important to remember how little of the building was visible from the videos.

Here's a reminder:

And:

 

[jaydeehess]

The buckling shown in NIST's simulation, and much more importantly, as described by the witness, was an OUTWARD buckling of the entire lower wall of the north face. Pretty much as shown in the screen grabs above.

The point of this is that the period of free fall is very likely directly associated with the formation of this low kink. As soon as the (approximately 8 story) 3 knuckle kink forms, the external north walls ability to support load goes to near zero. And one would fully expect a near free fall collapse.

As I've stated previously, the 8 - 10 story collapse that had already happened across the entire core, at the same elevation as this external kink, supports "building on stilts" interpretation of events. And these images show the buckling of the stilts.

When the core is gone, it takes the major support on the south end of the cantilever girders between core and north face, over the older substation structure. that would tilt those girders. With the increase of the remaining large exterior columns rising its rather intuitive that the lower columns buckled outwards.

 

[Seymour Butz]

Even minor delays would have been quite observable in the dropping roofline.

And indeed there was.

The first ~1.75 seconds were at less than FFA.

Your challenge has been met.

 

[jaydeehess]

And indeed there was.

The first ~1.75 seconds were at less than FFA.

Your challenge has been met.

Even prior to that 1.75 seconds the kink had formed and the roofline, every visible floor, was tilting in towards it, which means that the entire north side of the structure except the corners, was already moving downwards. The line along the kink was moving faster than points further out from that line.

IOW the perimeter column failures STARTED when the kink formed!

 

[beachnut]

Which is a classic indicator of a highrise lower core implosion. ...y?

Only for 9/11 truth followers. Looks like MM is giving guidance on what woo to spew. Miragememories failed, are you picking up where your agent for aviation woo inquiries left off - complete failure, no evidence. Love the look likes stuff, simile is not evidence.

Where does 9/11 truth, in the fantasy of CD, get the silent explosives with no blast damage? Or is it thermite, with zero damage to steel, magical thermite.

Where is the engineering stuff? Evidence for CD? How does the overwhelming evidence go lost for so long? I got it, the overwhelming evidence tag line is to fool gullible followers; a big lie.

 

[jaydeehess]

Which is a classic indicator of a highrise lower core implosion.

No, it's a classic indication of the loss of support from column 79 and most likely a few others nearby which failed shortly after column 79. The fact of that loss means nothing as to why those columns failed.

However, at this point there is nothing accelerating at 'g'.

Following a core implosion, the first downward sign of global failure was the roofline sinking in the middle followed by the three corners dropping in sync. At that point, for a few seconds, WTC 7 dropped at an unimpeded descent speed comparable to that of a falling safe.

Well not quite. The western corner slightly leads the eastern corner, and of course the center columns of the north face was already moving. Of course the SW corner did not even exist for several floors after WTC debris ripped it out. Even at the time which you refer to here, all corners dropping, there is still nothing accelerating at 'g'. Given the previous loss of the SW corner it's not particularly surprising that the larger western side from the kink gave out first. Of course that section also encompassed the older substation structure with the modern WTC7 having been built on a 'foundation' that was constructed half a dozen storeys above grade. Essentially the upper 40 storeys of the western 2/3rds of the north side was on stilts over the Con-Ed substation.
But you knew that, it's just inconvenient for you to contemplate how this would affect collapse.

The corner dropping is a good point to observe the initiation of global collapse.

Sure if you don'the care about how the other parts of the structure were moving or about the fact that the collapse sequence is quite obviously close to 20 seconds long, for much of which the corners don't move.

Controlled demolition, as everyone knows, best explains WTC 7’s balanced core failure. The ‘induced’ implosion of WTC 7’s lower core, was so balanced, it kept the falling building at a level posture just as it went into 8 stories of free fall. The distribution and timing of the core’s collapse needed to be very well balanced. The alternative, an unbalanced failure, without the benefit of ‘designed’ implosion equalization, would result in an off balance failure, hence a topple kind of collapse.

The Fitterman building's owners would like you to note that the eastern portion of WTC took a large chunk out of their property. On the other side over the short axis of WTC7, the western 2/3rds went towards WTC6 which made no difference to the owners of that structure since it was already destroyed by WTC1&2 debris.

In point of fact WTC 3,4,5 & 6 were all utterly destroyed, as we're the Fitterman and several other sundry buildings. If you dispute this then please point out which was repairable.

Point is WTC7 broke in two, part toppled to the NE, the rest to the S. But that is inconvenient to your beliefs so you ignore it.

So this means you are a supporter of the NIST’s hypothesis, but you’re not interested in explaining how roaming fire activity forced WTC 7 to suddenly drop. And so gracefully?

Lol,,, hey if you video me dancing from a mile away I look graceful too. Check it out in detail and,,,, not so much.

Yes I am interested in how fire can cause steel structure to fail. BTW there is a century of a scientific investigation into that very subject. One result of which has been the development of fairly accurate computer simulation programs of fire intensity and rate of spread through structurss. NIST used one of these. AE911T disputes NIST's fire Sim by having a carpenter draw pictures in MSpaint.
Then there are the FEAs done for the insurance case Larry Silverstone brought to court, and lost.
As NIST did, that study also concluded that fire caused the initial failure that began a sequence of progressive collapse. AE911T disputes that fire did this, instead, as you also say, that explosives were used. Yet I am not aware of any actual work having been done on an explosives sequence that AE911T or anyone else , has done. Just bald assertions, no evidence, no work, no working hypothesis beyond "boom-booms done it'.

 

[GlennB]

The distribution and timing of the core’s collapse needed to be very well balanced. The alternative, an unbalanced failure, without the benefit of ‘designed’ implosion equalization, would result in an off balance failure, hence a topple kind of collapse.

Something like this, you mean? :

 

[Criteria]

”In the case of WTC7, the inside of the building had collapsed from floors 5 to 15 across the width of the building, the stronger, highly redundant outer walls were still standing, producing a shelled out "building on 10 story stilts".

The "tap" on the side walls was outward, not inward, and was provided by the internal falling debris which built up in the lower floors and (what a shock, I tell you!) did not want to stack itself neatly at the end of its fall. The debris pile put a sudden outward load on the lower, outer walls.”

Do you honestly believe that WTC7 suffered a fire induced internal structural collapse that pulled on the north face with minimal deformation and glass breakage, and then created an internal debris pile that ‘tapped out’ 8 stories of the remaining perimeter walls — that your 10 story interlocking steel stilts all failed simultaneously!!?

That is quite a piece of symmetrical magic for a 47-story office tower with a football field-sized footprint.

Following a core implosion, the first downward sign of global failure was the roofline sinking in the middle followed by the three corners dropping in sync. At that point, for a few seconds, WTC 7 dropped at an unimpeded descent speed comparable to that of a falling safe.

”Indicates incompetence in basic physics; an unimpeded body falls at constant acceleration, not at a specific speed.”

Indicates your inability to read.

I said the descent speed was unimpeded (free fall acceleration). I did not say that the descent speed was constant.

By the time you see the moment frame collapsing... there is nothing left inside the building... It was like a hollow 4 sided trapezoid which had the bottom pulled out from under it at about floor 8.

Even if you were correct, that WTC7 was effectively no more than “a hollow 4-sided trapezoid”, you make no attempt to explain how fire could have simultaneously pulled 8 stories out from under it.

”But you bring up the exact reason that I think that it happened due to the mechanism I described. The falling debris alone would put a very large inward pull force on the outside walls. From the mechanism you describe, I would fully expect the buckling to be an INWARD buckling.”

A large inward pull force that failed to significantly deform the building’s perimeter wall or cause much window breakage.

”The buckling shown in NIST's simulation, and much more importantly, as described by the witness, was an OUTWARD buckling of the entire lower wall of the north face. Pretty much as shown in the screen grabs above.

The point of this is that the period of free fall is very likely directly associated with the formation of this low kink. As soon as the (approximately 8 story) 3 knuckle kink forms, the external north walls ability to support load goes to near zero. And one would fully expect a near free fall collapse.

As I've stated previously, the 8 - 10 story collapse that had already happened across the entire core, at the same elevation as this external kink, supports "building on stilts" interpretation of events. And these images show the buckling of the stilts.

NIST’s simulation is problematic because it not only fails to credibly duplicate the video record, it is based on input data which the NIST refuses to make public.

If you are going to claim eyewitness support for your beliefs, could you please provide the source.

If I read you correctly, you propose that only the internal structure initially failed — pulled inwards towards the core as it collapsed downward. That this “pull-in” was followed by a simultaneous 8-story ‘blow-out’ that supposedly explains the corner-to-corner symmetry of the free fall part of the collapse.

Oh, and that the ‘blow-out’ was caused by the internal debris pile forming such a nicely symmetrical shape as to push against and pop-out those 8 stories of perimeter wall, simultaneously.

I have to ask.

If the internal debris pile pushed against, and presumably through, the lower perimeter walls, and caused their simultaneous failure over 8 stories, where did the necessary unobstructed vertical space come from that allowed the WTC7 shell to drop at free fall acceleration?

 

[jaydeehess]

Do you honestly believe that WTC7 suffered a fire induced internal structural collapse that pulled on the north face with minimal deformation and glass breakage, and then created an internal debris pile that ‘tapped out’ 8 stories of the remaining perimeter walls — that your 10 story interlocking steel stilts all failed simultaneously!!?

Specious, hyperbolic and erroneous description of what actually happened. You know very well that fire is only concluded to have produced the intial, local failures which in turn lead to other failures and progressed to global collapse.
Each cantilever girder had their major support at their ends, in the core, and set back from the north perimeter wall. Horizontal progression through the core took out the southern end columns under those girders.

Indicates your inability to read.
I said the descent speed was unimpeded (free fall acceleration). I did not say that the descent speed was constant.

Referring to a situation in which a velocity is changing it would be customary and correct to refer to it as "acceleration".

Even if you were correct, that WTC7 was effectively no more than “a hollow 4-sided trapezoid”, you make no attempt to explain how fire could have simultaneously pulled 8 stories out from under it.

Once again with the knowingly erroneous description. Do you really believe that the commonly accepted narrative is that fire directly caused 8 storeys to fail? I fail to comprehend how anyone could assume that anyone has put that forth anywhere. Fire caused the initial structural failure that progressed through an already damaged, assymettricaly constructed building with long span open floors built largely over a pre-existing structure.

Then there is a description you ignore, concerning your supposed simultaneous column failures.
The western corner of the north face slightly leads the eastern corner, and of course the center columns of the north face were already moving. Of course the SW corner did not even exist for several floors after WTC debris ripped it out. Even at the time which you refer to here, all corners dropping, there is still nothing accelerating at 'g'. Given the previous loss of the SW corner it's not particularly surprising that the larger western side from the kink gave out first.

NIST’s simulation is problematic because it not only fails to credibly duplicate the video record, it is based on input data which the NIST refuses to make public.

Explain exactly why these points are a problem, and why thereally is little outcry referencing them in the engineering community, particularly from the ASCE.

If I read you correctly, you propose that only the internal structure initially failed — pulled inwards towards the core as it collapsed downward. That this “pull-in” was followed by a simultaneous 8-story ‘blow-out’ that supposedly explains the corner-to-corner symmetry of the free fall part of the collapse.

NOT symmetric, only three corners existed at lower levels after WTC collapsed.

Oh, and that the ‘blow-out’ was caused by the internal debris pile forming such a nicely symmetrical shape as to push against and pop-out those 8 stories of perimeter wall, simultaneously.

He can address this too, but where did you get that idea from?
The NIST computer sim clearly illustrates the north face buckling outward at about the 8th floor.

 

[Dave Rogers]

I said the descent speed was unimpeded (free fall acceleration). I did not say that the descent speed was constant.

Nice dodge to cover the fact that you forgot freefall specifies an acceleration rather than a speed. Try to choose your words more accurately next time you're trying to sound clever.

Still, since that's the only part of my post you take issue with...

Dave

 

[beachnut]

... That is quite a piece of symmetrical magic for a 47-story office tower with a football field-sized footprint.
...

Why does 9/11 truth keep repeating the big red flag of ignorance, "symmetrical", and in this case adding magic.

7 WTC collapse was not symmetrical, and since the interior was collapsing many seconds before the penthouse fell, and then finally the facade fell; the free-fall is a non-issue.

When you come up with the sounds of explosives, and or, some thermite evidence; you lost this one; just like MM did with his failed lies and idiotic claims. Is MM coaching your failed attempt to back in CD?

LOL, you now have no clue what engineering is.

NIST’s simulation is problematic because it not only fails to credibly duplicate the video record, it is based on input data which the NIST refuses to make public.

Serious: as an engineer, I am trying to say, don't say this again; the simulation is not suppose to look like a movie, it is a math, engineering, not a movie by Disney.
Saying is exposes a great ignorance of engineering simulation on structures, and thus give you zero credibility when talking to engineers; I am an engineer, and this single statement means you don't understand engineering, you like BS, CD, and other fantasy versions of 9/11.

If you can't make up the input data you need for a simulation, you are not an engineer. Do the best you can; oops, repeating BS about symmetry, and other 9/11 truth idiotic tag lines to fool people.

Why does 9/11 truth think buildings have more mass? You can't rent mass for office space, the more air, empty space, the more you can rent.

Why would free-fall be a sign of CD? CD is a basically a gravity collapse, thus why would a fire induced gravity collapse not look like a gravity collapse... lol
9/11 truth, the only people on earth who know less about 9/11 than 19 terrorists, who died on 9/11.

 

[JSanderO]

The problem I have with the outward bulge low down... is that I don't believe there is any video or still images of this... it's all part of their model. Fine.

But there is perhaps a better explanation than bulge... it's pull in of the 26 columns below floor 7

We can see the upper section develop a tall vertical kink which looks to me as if the entire trapezoid rotated anti clockwise about a virtual axis on somewhere on the NW side of the plan... The NE corner seems to be moving more / faster than the north facade and so kink is created likely in the line of girder 44-79.

For the entire trapezoid moment frame to drop AND rotate as much as it seems to... I would think the entire core was gone when this motion is observed... and gone down to the ground. But for the entire moment frame to rotate as it seems to... it has to break away from the footings... and there were actually much fewer below (26) than there were columns above floor 7 (57).

The entire east side below floor 7 had only 4 columns on footings....
The entire west side below floor 7 hand only 5 columns on footings ...
The entire north side below floor 7 had only 7 columns on footings
the entire south side below floor 7 had only 10 columns on footings

26 columns supporting 57 using transfer trusses on the perimeter between floors 5 & 7

COLUMNS SHOWN IN RED IN SKETCH BELOW
KINK LOCATION SHOWN IN PURPLE

It looks to me when you examine the structure supporting the moment frame BELOW 7....it more than likely was pulled INWARD by the core collapse leaving the moment frame without support for 8 floors or 104

The rotation is explained by the fact that the moment frame was resting on the Con Ed containment in the NW corner

 

[jaydeehess]

The problem I have with the outward bulge low down... is that I don't believe there is any video or still images of this... it's all part of their model. Fine.

But there is perhaps a better explanation than bulge... it's pull in of the 26 columns below floor 7

We can see the upper section develop a tall vertical kink which looks to me as if the entire trapezoid rotated anti clockwise about a virtual axis on somewhere on the NW side of the plan... The NE corner seems to be moving more / faster than the north facade and so kink is created likely in the line of girder 44-79.

For the entire trapezoid moment frame to drop AND rotate as much as it seems to... I would think the entire core was gone when this motion is observed... and gone down to the ground. But for the entire moment frame to rotate as it seems to... it has to break away from the footings... and there were actually much fewer below (26) than there were columns above floor 7 (57).

The entire east side below floor 7 had only 4 columns on footings....
The entire west side below floor 7 hand only 5 columns on footings ...
The entire north side below floor 7 had only 7 columns on footings
the entire south side below floor 7 had only 10 columns on footings

26 columns supporting 57 using transfer trusses on the perimeter between floors 5 & 7

COLUMNS SHOWN IN RED IN SKETCH BELOW
KINK LOCATION SHOWN IN PURPLE

It looks to me when you examine the structure supporting the moment frame BELOW 7....it more than likely was pulled INWARD by the core collapse leaving the moment frame without support for 8 floors or 104

The rotation is explained by the fact that the moment frame was resting on the Con Ed containment in the NW corner

I agree on the rotation. Obviously the eastern portion did rotate. In the video we see it tilting to the west and it ended up smacking the Fitterman bldg to the NE. So unless Gage et al are going to say the Fitterman was a CD then WTC7's eastern section rotated as it fell.

I keep saying this though, the cantilever girders had their heaviest columns at the south end in the core of WTC 7 and at the north end wall. (iirc the norh wall on lower floors was set back from the facade of higher floors, thus the term "cantilever").
With the south end columns destroyed as collapse progressed horizontally through the core, those girders will start to crush the lighter columns in the substation. So the girders are inclined, AND a heavy rain of debris is hitting them mostly nearer the core. That is going to hit those inclined girders and force the northern columns to tilt,,, outward at their connection to the girders.
Seems truthers think that exterior columns are continuous from foundation to rooftop. Your images illustrate the fallacy in that.

 

[Criteria]

”It looks to me when you examine the structure supporting the moment frame BELOW 7....it more than likely was pulled INWARD by the core collapse..”

Which is what a controlled demolition would have done.

Everything points to a controlled demolition induced implosion.

Nothing to points to a fire-induced implosion.

Yet, because the observable evidence supports an ‘unpalatable’ inside job, flag wavers buy into the absurd hypothesis of a historically unique fire.

 

[JSanderO]

Correction to the diagram of the # of support columns of the moment frame.

Corner shared columns are shown in GREEN

Total # if moment frame columns = 57
Total # of columns supporting moment frame = 27

47% of the moment frame columns had axial direct coupling to the foundations.... less than 1 out of every 2 columns.

The north side had the center 50% with no support under it (on cantilevers).

Tentative conclusion:

There is very little likelihood that there was a bulge from mass accumulation at floor 7. The 3.25 second ~FF acceleration was because the moment frame dropped from the top of 7th floor (104' above ground)

 

[jaydeehess]

Which is what a controlled demolition would have done.

Everything points to a controlled demolition induced implosion.

Nothing to points to a fire-induced implosion.
Yet, because the observable evidence supports an ‘unpalatable’ inside job, flag wavers buy into the absurd hypothesis of a historically unique fire.

No one but you says anything about fire directly causing the global collapse.

 

[JSanderO]

Which is what a controlled demolition would have done.

Everything points to a controlled demolition induced implosion.

Nothing to points to a fire-induced implosion.

Yet, because the observable evidence supports an ‘unpalatable’ inside job, flag wavers buy into the absurd hypothesis of a historically unique fire.

The conclusion is that the fire (no evidence of CD) acted below floor 8. NIST might claim that the collapse of 79 triggered the collapse of the structure below 8... falling down on it. MAYBE...

Or it fell because the structure below it gave way.

There is so little evidence (none) of what was or was not happening inside below 8 it would only be speculation. But if the entire 41 stories is supported on a 3 immense field erected trusses and a 10 huge girders connected to them... you've put all your eggs in one basket.

NB one of those trusses can fail from a field made splice connection which was simply bolted. It doesn't take as much energy to fails bolts/splices than it does to fail a massive steel rolled section or plate.

The collapse was likely originated from a field made bolted connection.

BBL I have to step a mast.

 

[beachnut]

Which is what a controlled demolition would have done.

Everything points to a controlled demolition induced implosion.

Nothing to points to a fire-induced implosion.

Yet, because the observable evidence supports an ‘unpalatable’ inside job, flag wavers buy into the absurd hypothesis of a historically unique fire.

You made all this up based on your common sense? Open mind? It appears 9/11 truth followers are gullible on 7 WTC, repeating the BS of symmetry (the sign of woo), and failing to realize the interior failed first, and there was no support for the free-fall time, part of the over 18 seconds of building failure.

Who did you get to plant the silent explosives and never talk about it? How does 9/11 truth make up delusional claims this stupid?

Fact, evidence = fires not fought point to fire-induced failure. I guess 9/11 truth lies and ignores the fires, they can't do the science so they post lies and nonsense based on failed common sense.

Where is a building going to fall? It falls down.

Your evidence for the inside job is an over active imagination based on bias, and zero knowledge of fire, steel, and structural engineering.

Is this the best you can get from the proxy miragememories. I can't believe you know MM, and have the same failed claims based on simile. Did MM help fool you with 9/11 truth claims?

Where do you get the silent explosives in your fantasy of CD? Source please.

 

[Criteria]

”That is quite a piece of symmetrical magic for a 47-story office tower with a football field-sized footprint.”

Why does 9/11 truth keep repeating the big red flag of ignorance, "symmetrical", and in this case adding magic.

7 WTC collapse was not symmetrical, and since the interior was collapsing many seconds before the penthouse fell, and then finally the facade fell; the free-fall is a non-issue…”

Maintaining such a degree of collapse symmetry is not a reasonable expectation for a natural self-guided collapse.

You fail to explain your reasoning that free fall was a non-issue. You fail to show that the interior was “collapsing many seconds” before the penthouse fell (east or west). You fail to explain how a free-falling facade is a non-issue. In short, you make lots of assertions but make no attempt to support them with some kind of reasoning.

”I am an engineer, and this single statement means you don't understand engineering, you like BS, CD, and other fantasy versions of 9/11.”

As anonymous Mr. Beachnut, you can make whatever claim as an authority you wish, but when your reasoning is BS or empty, so becomes your credibility.

”Why would free-fall be a sign of CD?”

Controlled Demolition normally relies on blasting away a building’s support.

What happens when you blast away all of a building’s support?

It drops at free-fall acceleration unless it encounters vertical resistance.

Without the use of human engineering, how could roaming office fires uniformly and simultaneously destroy enough building support to create free-fall of the interior or the exterior of a 47-story steel-structured office tower?

In both cases, controlled demolition (CD) can unquestionably do this, and “free-fall” would be an observable “sign”.

”CD is a basically a gravity collapse, thus why would a fire induced gravity collapse not look like a gravity collapse... lol“

Aren’t all collapses gravity collapses?

You are saying that you believe that it is possible for roaming fires to self-engineer the collapse of a 47-story steel-structured office tower with the same appearance as that which would be induced by human controlled-demolition engineering. A claim that up until 9/11, had never been proposed, and to this day, has never been proven possible.