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

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Seymour Butz said:
I see at best 1 1/4" until the lower (east) flange is pushing against the column 79.

The girder is at an angle to the column, and as such, the full contact area to the west wouldn't have been able to restrain it at all, especially when one factors in the heated girder will be exerting a lot of force against the column flange through the action of the heated floor beams. A more likely scenario is that the girder flanges would have smeared over...

The stiffeners were set back 3/4" in the drawing. They were NOT flush to the outer edge of the girder. So at least 3/4" would have folded easily = less support than you are claiming.

So if the girder is only being supported by say, 60% of its planned area, at what temp does the steel fail and the girder drop?

I see a lot of your arguments depend on ambient temps of the seat plates, and totally ignore the heating effects - creep, increase in malleability, ductility, etc.....
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No, I'm assuming that everything is about the same temp, as would be the case.

Thermal expansion of the girder would put more of it over the support plate.

But all that ignores the point:

Thermal expansion cannot result in 5.5" of axial elongation because sag would shorten the beams more than they expanded before then.

At 600oC the beams would expand 4.68" and lose 0.27" to sagging for a net elongation of 4.41"

At700oC the beams would expand 5.63" and lose 3.495" to sagging for a net elongation of 2.135".

The NIST theory of the beams pushing the girder off its seat is not possible.
 
Christopher7 said:
A collapse due to normal office fires.
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You've GOT to be kidding.

How would you like it if you made an innocent mistake and someone (someone CLUELESS) started making unfounded accusations towards you? Maybe you should start treating people as you'd like to be treated yourself, Mr Sarns.

You know DAMN WELL that the NIST report, with it's potential flaws, still explains the day's events better than any other report. If not, lets see it.

Lets see that detailed report that uses science and reason instead of mindless accusations to come to its conclusions. You got one?

Nah, didn't think so.

Just like every other truther, all you have is unfounded, asinine, mistake-filled emotional drivel. Not a shred of actual science in over TEN years.

Give it up, kiddo. Find a new hobby. You guys SUCK at this one.

Thermal expansion cannot result in 5.5" of axial elongation because sag would shorten the beams more than they expanded before then.
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I love how you write that stuff as if you have the faintest idea what you're talking about. It's funny.
 
Christopher7 said:
No, I'm assuming that everything is about the same temp, as would be the case.

Thermal expansion of the girder would put more of it over the support plate.

But all that ignores the point:

Thermal expansion cannot result in 5.5" of axial elongation because sag would shorten the beams more than they expanded before then.

At 600oC the beams would expand 4.68" and lose 0.27" to sagging for a net elongation of 4.41"

At700oC the beams would expand 5.63" and lose 3.495" to sagging for a net elongation of 2.135".

The NIST theory of the beams pushing the girder off its seat is not possible.
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It's so adorable when the truthers try to pretend they understand engineering or math by using terms they heard somewhere....

Simple adorable!
 
newton3376 said:
It's so adorable when the truthers try to pretend they understand engineering or math by using terms they heard somewhere....

Simple adorable!
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When faced with facts you can't dispute you and Noah and many others here resort to denial and childish insults.
 
newton3376 said:
It's so adorable when the truthers try to pretend they understand engineering or math by using terms they heard somewhere....

Simple adorable!
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And he is still trying to pretend that it is a single factor phenomenon.... well two factors in recent times - thermal expansion and sag. At this rate of recognising factors we should come back next year.

...note also the 3 decimal place precision in girder length change. Whilst totally ignoring all the other movements in a building that is experiencing fire.

So one girder moves pushed by one set of beams...

...whilst everything else stays right where it was.

Presumably the girder and beam set were the only bits which were heated?
 
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Christopher7 said:
When faced with facts you can't dispute you and Noah and many others here resort to denial and childish insults.
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How the hell would you know? You've yet to present any ”facts” I can't deny.

All you have is one or two silly little items you alone feel is weird, thinking that they prove some massive conspiracy you are too scared to define.

You're wrong. GET A NEW HOBBY.

Millions of witnesses, kiddo.
 
ozeco41 said:
So one girder moves pushed by one set of beams...

...whilst everything else stays right where it was.

Presumably the girder and beam set were the only bits which were heated?
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It's the NIST theory, not mine. I just showed that it is impossible.
 
ozeco41 said:
...note also the 3 decimal place precision in girder length change. Whilst totally ignoring all the other movements in a building that is experiencing fire.
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Not since femr2 have I seen such precision where there was none.

Christopher7 said:
It's the NIST theory, not mine. I just showed that it is impossible.
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NIST had three decimal places for the girder length change? Not bloody likely, but thrill me and post a link.

Clueless. In every way.
 
Christopher7 said:
It's not a claim, it's a fact:
NIST appendix L pg 26
Around 4:45 p.m., a photograph showed fires on Floors 7, 8, 9, and 11 near the middle of the north face; Floor 12 was burned out by this time.
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IF you're right, and that's a biiiig IF.... then you have shown NIST wrong, and instead shown that thermal contraction to be more likely.

(But of course an FEA would be needed to show the thermal expansion explanation to be improbable since you are overlooking many factors)

It also would show, once again, that explosive/thermite cd not necessary to cause the collapse, and also shows your statements about how cd is necessary...... etc.... to be wrong.

Would you be comfortable with that?
 
Christopher7 said:
No, I'm assuming that everything is about the same temp, as would be the case.
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But you're also ignoring the weakening of the horizontal support plate and flanges of the girder edges.

Thermal expansion of the girder would put more of it over the support plate.
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Agreed. BUT..... how much room is there for the girder to expand. I see about 1 1/4" into col 79. And what... 2" into col 44? (correct me on this) So if the girder thermally expands 5", with only 3 1/4' of room available, what happens to the girder when it tries to expand the other 1 3/4"?



The NIST theory of the beams pushing the girder off its seat is not possible.
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SO then the rational conclusion to your belief is that thermal contraction caused the failure, and again disproves cd.

Are you comfortable with that?
 
jaydeehess said:
C7 you are free to consider any of my proposals above in your quest

You and AE911T are free to produce your own technical study, perhaps an FEA on the beam/girder/floor system in response to fire

if the fire was burned down and both beams and girder had sagged then you can do what the CTBUH suggested and determine if the girder could pull away to the west and/or north
If the beams and girder first expanded then sagged you could determine if it was pushed and pulled and how much, to the west and north

If you actually do an FEA you could determine where the CD (explosive or incindiary) would have to have been, the size of the charges and the timing

I have no problem with the proposal that large unfought fire caused the initial collapse and the building design allowed this local failure to progress to global collapse so I haveittle impetus to perform said studies
You otoh have that impetus!

BTW, it would be advisable, when writing up the paper for this study you refrain from your habit of calling the NIST report authors 'liars' if you wish to be thought of as something other than a fanatic.
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Christopher7 said:
When faced with facts you can't dispute you and Noah and many others here resort to denial and childish insults.
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Chris, when will you and your engineer be preparing a technical paper, free of accusations of fraud and lies, and present it to an engineering journal or popular peer review magazine such as Scientific American? I am quite sure you would be able to get funding from AE911T though according to you all the funding you would need is printing costs. You claim to have determined all that need be determined already.
You have presented your arguement in this 20+ page thread as well as several other related and long winded threads. All that need be done then is to compile all you have said into a cohesive and cogent paper and present it. You have an accredited engineer to put forth as lead author.

Are you choosing to simply argue the validity of your research in internet forums and thus satisfied in getting absolutely no where?

What, exactly is the point of your continued arguement on this subject exclusively on internet forums?
 
Seymour Butz said:
But you're also ignoring the weakening of the horizontal support plate and flanges of the girder edges.



Agreed. BUT..... how much room is there for the girder to expand. I see about 1 1/4" into col 79. And what... 2" into col 44? (correct me on this) So if the girder thermally expands 5", with only 3 1/4' of room available, what happens to the girder when it tries to expand the other 1 3/4"?





SO then the rational conclusion to your belief is that thermal contraction caused the failure, and again disproves cd.

Are you comfortable with that?
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He's ignored all of this before.
jaydeehess said:
Wait,,,, so the NIST theory has it that the girder was pushed/walked across the seat to the point where it failed/fell off the seat. Chris now wishes to argue that the girder sagged which would pull axially along the girder and shorten the depth of girder residing on the seat. It would also reduce the stiffness of the steel of course, including that portion which sat on the seat. In either case we have less girder steel on the seat and as Chris wishes to include the effect of the heat on that steel, we have more malleable steel on that seat , the combination of which would serve to have the seat-girder connection fail.

Then there is the scenario in which the fire begins burning down and the steel cools and contracts in which if Chris is correct the sagged girder now shortens axially even more, or as the CTBUH brought up, the sagged beams cool and shorten and pull the girder off its seat. IN ANY CASE the girder comes off the seat!
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,,, and I am an electronics tech.
 
Christopher7 said:
A collapse due to normal office fires.
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Sarns, I'd call an office fire started by a building hit by a plane collapsing onto of the building in question far out of the range of what could be considered "normal".
 
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