WTC7 and the girder walk-off between column 79 and 44

[tfk]

For the other readers...

In case anyone is still unclear as to why the following is a pathetic joke of an analysis ...

NCSTAR 1-6 just tries to say the core was thermally weakened.

NIST doesn't say anything of the sort.

It does not provide a substantiated analysis for that statement.

Not in the slightest surprising.

Since NIST doesn't say it.

Tony imagines it.

Additionally, it does not provide any substantiation for overload and failure of the east and west perimeter wall columns, which had a factor of safety against gravity loads of 5.00 to 1. The NIST load redistribution on the perimeter is at worst about 30% more than what was normally on the columns which was about 20% of their capacity. So here we have 1.3 x 20% = 26% of their capacity. In that case the columns would have still had a factor of safety of just under 4.00 to 1.

And the massive, giant fail is in this paragraph.

Once again, Tony is pulling Factors of safety out of his keister that ONLY apply to the building AS BUILT.

After the plane had applied a 100 ton, 500 mph "adjustment" to the geometry, connections, etc., of the building, the original factors of safety had flown away.

Along with any stupid, simple calculation that Tony might attempt to imagine.

Those columns were loaded to their capacity & beyond. They were loaded in ways that they never had to endure before, and were never designed to handle. That is, in extreme bending to compensate for the damaged & severed columns.

Tony's calculation is proven ludicrous by the simple fact that NIST's models (the very one that he is trying to quote) had NO single load on any columns. The load on all of the columns changed drastically over time as the core expanded, crept, cooled & shrunk.

So we have this big hole in the official story ...

The only "big holes" in sight are the one in Tony's head & the other in his insipid calculation.

 

[BasqueArch]

I did the analyses for the girder to see if it could have walked-off in either a lateral or axial way and it could not have. Your supposition turned out to be wrong there and there is no longer any argument about it. The NIST girder walk-off collapse initiation scenario for WTC 7 has been proven to be impossible and it shouldn't be a surprise that they did not do a physical test to try and validate their theory there.

As for the NIST allegation that SFRM was knocked off by debris or vibration/flexing of the trusses on the opposite side of the building several floors above the aircraft debris in WTC 1, that is being shown to be impossible also, and it shouldn't be a surprise they didn't do a physical test for it either.

The NIST report conclusions are based on untenable theories and are therefore untenable themselves.

Whistling past the graveyard. You certainly have not proven your claims about the insulation or girder fall off. You should upload your girder calculations, inputs, assumptions to imageshack or photobucket so we can check.

There is no evidence for explosives or thermite having been used so that's out.

 

[DGM]

There would have been little flexing of things like floor trusses on the complete opposite side of the building several floors above the impact zone and certainly not enough to break off the SFRM.

I also bet there would not be enough flexing to cause reports of doors jamming in there frames..............................oh wait.

 

[Tony Szamboti]

I also bet there would not be enough flexing to cause reports of doors jamming in there frames..............................oh wait.

Flexing would not cause the SFRM to dislodge on all of the trusses on the complete other side of the building and the central core and several floors above the impact. The SFRM had an adhesive bond strength of somewhere around 2 to 2.5 psi. That is actually pretty strong for light airy stuff. Most industrial strength tapes only have an adhesive bond strength of about 4 to 5 psi.

TFK is simply blowing smoke and doing precisely what he is attempting to accuse me of. If what he were saying was true NIST would have done a test on some SFRM coated steel truss parts on a shaker table in the bat of an eye. They didn't. Why didn't they?

 

[DGM]

Flexing would not cause the SFRM to dislodge on all of the trusses on the complete other side of the building and the central core and several floors above the impact. The SFRM had an adhesive bond strength of somewhere around 2 to 2.5 psi. That is actually pretty strong for light airy stuff.

I work with the stuff fairly regularly. I always budget for repair because the stuff is in fact very fragile.


BTW, Who said it had to dislodge it all?

 

[DGM]

Most industrial strength tapes only have an adhesive bond strength of about 4 to 5 psi.

What kind of rigid/non flexible "tape" are you talking about? Have you ever seen a ceramic tile pop off a wall? What is the bond strength of tile adhesives (pick one, they're all well above your tape).

 

[Tony Szamboti]

I work with the stuff fairly regularly. I always budget for repair because the stuff is in fact very fragile.


BTW, Who said it had to dislodge it all?

There is little chance the trusses under the 98th floor were more affected by fire due to having their fireproofing dislodged. It is an unsubstantiated claim as there was no mechanism to remove it if the debris field was nowhere near it. NIST did no testing to prove vibration/acceleration and/or flexing could have caused it or that it was even a viable theory. Why didn't they do a test?

 

[Tony Szamboti]

What kind of rigid/non flexible "tape" are you talking about? Have you ever seen a ceramic tile pop off a wall? What is the bond strength of tile adhesives (pick one, they're all well above your tape).

SFRM is not rigid like ceramic tiles. It is composed of short thin ceramic filaments in a gypsum like binder, which is somewhat flexible. It is the binder which determines the overall flexibility.

 

[Justin39640]

Flexing would not cause the SFRM to dislodge on all of the trusses on the complete other side of the building and the central core and several floors above the impact. The SFRM had an adhesive bond strength of somewhere around 2 to 2.5 psi. That is actually pretty strong for light airy stuff. Most industrial strength tapes only have an adhesive bond strength of about 4 to 5 psi.

TFK is simply blowing smoke and doing precisely what he is attempting to accuse me of. If what he were saying was true NIST would have done a test on some SFRM coated steel truss parts on a shaker table in the bat of an eye. They didn't. Why didn't they?

I've accidentally knocked more SFRM off of trusses than you've ever seen in your life. The stuff is weak. You look at it wrong and it falls off.

 

[Justin39640]

SFRM is not rigid like ceramic tiles. It is composed of short thin ceramic filaments in a gypsum like binder, which is somewhat flexible. It is the binder which determines the overall flexibility.

Um, it's like a crust actually, and it's fragile as hell.

 

[Tony Szamboti]

Um, it's like a crust actually, and it's fragile as hell.

Why didn't NIST do a test to show it could come off due to the accelerations they calculated for the 98th floor on the opposite side of the building and several floors above the aircraft impact?

 

[Justin39640]

Why didn't NIST do a test to show it could come off due to the accelerations they calculated for the 98th floor on the opposite side of the building and several floors above the aircraft impact?

Why didn't they test the adhesive used on the tiles in the lobby? I would guess so the study didn't take 30 years. One would assume most of everything meant to protect the building was completely **********.

 

[Grizzly Bear]

I don't think the SFRM issue is the problem... like every other discussion TZ's focusing one single element and applying that condition to all of the others that factor in, or just sticking guns to that one single factor despite everyone else looking at the bigger frame of reference.

With the "girder walk off" it's been a discussion only of whether or not it expanded enough to dislodge... when quantifying it requires taking into account the structural response of the assembly, as well as any creep behavior.

A one-track mindset with all of this stuff means the discussion is kinda pointless. Everyone here seems capable of thinking about the effect of secondary, tertiary, etc factors which influence the primary - except for CM, TS or any one else speaking specifically about the OP. The idea's pretty simple

 

[tsig]

Flexing would not cause the SFRM to dislodge on all of the trusses on the complete other side of the building and the central core and several floors above the impact. The SFRM had an adhesive bond strength of somewhere around 2 to 2.5 psi. That is actually pretty strong for light airy stuff. Most industrial strength tapes only have an adhesive bond strength of about 4 to 5 psi.

TFK is simply blowing smoke and doing precisely what he is attempting to accuse me of. If what he were saying was true NIST would have done a test on some SFRM coated steel truss parts on a shaker table in the bat of an eye. They didn't. Why didn't they?

Buildings structures are connected.

 

[MileHighMadness]

Getting back to the main subject of this thread…the girder doesn’t just walk off column 79, it explodes off.

When the 4-7/8” high strength bolts connecting the girder to the column fail (shear off), they release a great deal of built up force and potential energy. That potential energy is converted to kinetic energy, and the girder quickly explodes off the bearing seat.

It would be like a bomb going off.

 

[ozeco41]

I don't think the SFRM issue is the problem... like every other discussion TZ's focusing one single element and applying that condition to all of the others that factor in, or just sticking guns to that one single factor despite everyone else looking at the bigger frame of reference.

With the "girder walk off" it's been a discussion only of whether or not it expanded enough to dislodge... when quantifying it requires taking into account the structural response of the assembly, as well as any creep behavior.

A one-track mindset with all of this stuff means the discussion is kinda pointless. Everyone here seems capable of thinking about the effect of secondary, tertiary, etc factors which influence the primary - except for CM, TS or any one else speaking specifically about the OP. The idea's pretty simple

It is his standard trolling tactic - one part of a suite of six actually:
1) He starts from the wrong end of the logic - working from perceived anomalies in the details rather than working from the known 'bigger frame of reference';
2) And makes wrong assumptions to set a false context for the discussions;
3) Then repeatedly forces 'discussion' down into the details;
4) And makes sure to limit discussion to one factor at a time;
5) Whilst pulling the 'reversed burden of proof' ploy; AND
6) Resorting to insult or ignore when anyone exposes his tricks.

C7 is better at the same game and CM is only making noise whilst hitching onto someone else's trolling so he gets a free ride.

Try these examples:

The east and west perimeter wall columns of the North Tower can be observed on video not to be bowed inwardly when the collapse started. Only the south wall, which was not on video tape, is alleged to have been bowed inwardly before the collapse.

Attempt to focus on single factor - evading reality of multi-factor cascading failure.

...The NIST analysis just implies collapse after the south wall was allegedly pulled inward by the trusses...

Switching objective to "NIST wuz wrong" when the discussion is about causes of failure - not whether NIST was correct.

... Do you care to explain how the failure of the south wall would effect a complete collapse, because NIST did not explain it?

Attempted 'reversed burden of proof' - based on Tony's strawman. So 'You prove my strawman wrong.'

...So we have this big hole in the official story where nobody explains how a south wall failure could cause a propagation across the building. That is why I asked you to try and explain it. If you really think it was a natural occurrence you should be able to do that.

A false claim - yet another strawman - to support another attempted 'reverse burden of proof'.

...Can you tell us how the debris field heading downward at 10.6 degrees from the impact at the 95th and 96th floors could have done this?

Ditto 'reverse burden of proof' - i.e. another example of 'you go chase this strawman'.

Gets boring don't you think?

As you said:

....The idea's pretty simple

 

[ozeco41]

Getting back to the main subject of this thread…the girder doesn’t just walk off column 79, it explodes off.

When the 4-7/8” high strength bolts connecting the girder to the column fail (shear off), they release a great deal of built up force and potential energy. That potential energy is converted to kinetic energy, and the girder quickly explodes off the bearing seat.

It would be like a bomb going off.

Another factor Tony needs to deal with.

 

[Sunstealer]

Tony has done no research on the fire-proofing. The wind was causing the fire proofing to be dislodged way before 9/11. Yep Tone, the wind.

every March and April when you had these windstorms and the building rocked back and forth, you would still knock some of the fireproofing down."

http://www.debunking911.com/fires.htm

So, slamming a fully fuelled jet liner at 500mph into the side of the building isn't going to anything substantial, but the wind well that's a bitch when it comes to fire-proofing.

 

[Sunstealer]

Getting back to the main subject of this thread…the girder doesn’t just walk off column 79, it explodes off.

When the 4-7/8” high strength bolts connecting the girder to the column fail (shear off), they release a great deal of built up force and potential energy. That potential energy is converted to kinetic energy, and the girder quickly explodes off the bearing seat.

It would be like a bomb going off.

Remember performing a tensile test on a dirty great big titanium alloy bolt with a colleague during my first job at a satellite manufacturer. Must have been 3/4 inch in diameter.

We had bets as to when this thing was going to fail. Was taking ages so we went out to get coffee. Just as we were coming back.

BANG!!

Thing had gone off like a bomb, walked into the test cell with coffee all down us to find only a bolt head. Where the hell was the rest of it? Turned out half of it was embedded in the partition wall right about where we'd been previously standing. Test failed where we hadn't expected it to. (hint: initial failure wasn't in the bolt.) People don't realise the PE until it's released

 

[pgimeno]

Wrong re flexing. The towers swayed, flexed over 2 feet past plumb and cycled in both directions. Ceiling tiles fell, sheetrock cracked, doors jammed. Damaged finishes down to the lobby. Fireball that blasted windows off their frames blasted SFRM. SFRM is fragile, you can scrape it off with your fingers. A layer of rust covered most steel, SFRM detatched off the flexing steel.

Now that I think about it, I don't remember any photograph of a piece of steel with SFRM in GZ. All I remember lacked it.