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

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Tony Szamboti said:
No, I wouldn't walk in a building that was creaking with fires in it, but I seriously doubt I would have predicted that a 610 foot tall building with a floor area the size of a football field like WTC 7 was going to collapse to the ground because of some creaking while it had fires in it.
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Your incredulity is unimpressive as an argument.

Tony Szamboti said:
It sounds like you are one of those "we can't possibly know anything because everything is in a state of flux, and anything can happen" handwringers who doesn't know enough to critique an engineering analysis.

3 decimal places are important to show where the limit of expansion occurred.

The temperature given is for the maximum possible expansion, no matter what the temperature reached. What are you even talking about with a margin of error?

Edited by jhunter1163: 
Edited for Rule 0.
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You have been assuming perfectly symmetrical deformation of an isolated piece of steel in a humongous grid system of a building that was on fire, creaking and leaning, and calculating it to 3 decimal places. I'm still not an engineer, but this seems insane to me.

Would another engineer please correct me if I'm wrong?


Tony Szamboti said:
You seem to be one of those guys who likes to say we can never know anything because it was all in a state of flux and anything could happen. Columns could even take coffee breaks and get back before anyone noticed under your thinking.

In reality, there is cause and effect and if the postulated cause doesn't provide the effect then it wasn't the cause. That is where we are with NIST's theory on the collapse initiation for WTC 7. It is impossible at all times since it can't happen under the worst conditions.
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A familiar refrain.
 
carlitos said:
You have been assuming perfectly symmetrical deformation of an isolated piece of steel in a humongous grid system of a building that was on fire, creaking and leaning, and calculating it to 3 decimal places. I'm still not an engineer, but this seems insane to me.

Would another engineer please correct me if I'm wrong?
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IANAE. However, I think you're on the right track. (The number of decimal places isn't really the issue; the conclusions wouldn't change if Tony rounded to the nearest tenth. It's the confident inference that NIST's explanation is impossible that seems misplaced.)

It strikes me that NCSTAR 1-9 states that in its ANSYS structural analysis, Case B,

...the girder between Columns 44 and 79 buckled and walked off the bearing seat between 3.7 h and 4.0 h. Girder buckling* was due to the combined effects of (1) gravity loads from the floor beams, (2) lateral westward displacement due to the thermal expansion in the east floor beams, and (3) increased axial loads due to thermal expansion in the girder. [p. 527]

*[ML note: This reference presumably applies to all four girders discussed in this paragraph: 26-81, 79-80, 80-81, and 44-79.]
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Tony seems to think he has rebutted the ANSYS analysis -- sort of like Indiana Jones demonstrating why guns are better than swords. While it is possible in principle for a simple analysis to sanity-check a complex model, I don't think he has offered much of a case. I don't have the expertise to work out what his best possible case might be; then again, at this point one might surmise that he doesn't, either. I am not surprised that this line of argument has had so little impact on the professional community in general.

(And, yes, ozeco has made much the same point repeatedly. I'm focusing on the NIST analysis because it seems to me that Tony hasn't even rebutted that. It's quite reasonable to point out that even if he had, he would be far from establishing sabotage as the most likely hypothesis.)
 
Thanks. It's not just the claimed degree of precision (which has now been parroted here by Christopher7), it's that he also had the expansion sagging (and other deformations IIRC) being exactly symmetrical, and then measures that to a very precise degree.

Tony Szamboti said:
Where did you get 2" shorter per side? 0.8" + 0.376" = 1.176". Can't you add?

There is 1.2" of clearance each side at room temp and the 3.985 expansion causes about 0.8" interference each side that would cause deformation. Couple that with 0.376" contraction due to sagging and the total combined contraction from buckling due to interference and sagging would be 0.8" + 0.376" or about 1.18" shorter per side.

...

What you did by trying to extend the contraction to 2" per side, when I clearly showed it was just 1.18" per side, even at 700 degrees C, is why I ty not to post on forums like this anymore.

(incivility snipped)
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I can't imagine that heat would have been applied to the entire piece of steel at the same degree over the same time, or that the leaning wouldn't have changed the stresses / creep and maybe how heat would have affected things.

Would love a technical person to comment on this, in case I'm way off base and steel pretty much behaves the same at both ends in a fire, perhaps due to the way it functions as a heat sink or something. I know that engineers tend to be precise when it's appropriate, so happy to be wrong.
 
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Tony Szamboti said:
Football field size 47 story buildings don't suddenly collapse because of thermal creep and I can offer another explanation. There is only one explanation and it hasn't been investigated yet.
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After seven hours of unfought fire.
 
carlitos said:
Thanks. It's not just the claimed degree of precision (which has now been parroted here by Christopher7), it's that he had the expansion being exactly symmetrical, and then measures that to a very precise degree.
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The 0.8" + 0.376" = 1.176" is an eye-rubber all by itself (although forgivable in a board post). I was only trying to forestall likely attempts to misconstrue your point.

Incidentally, I wish I had a dollar for every time a conspiracist operating in my area of expertise made a basic mistake, I pointed out the basic mistake, and s/he huffily complained that I was nitpicking minutiae. Some basic mistakes are a lot more important than others, but a pattern of basic mistakes is a flashing red light.
 
MarkLindeman said:
The 0.8" + 0.376" = 1.176" is an eye-rubber all by itself (although forgivable in a board post). I was only trying to forestall likely attempts to misconstrue your point.

Incidentally, I wish I had a dollar for every time a conspiracist operating in my area of expertise made a basic mistake, I pointed out the basic mistake, and s/he huffily complained that I was nitpicking minutiae. Some basic mistakes are a lot more important than others, but a pattern of basic mistakes is a flashing red light.
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So what's the explanation of your area of expertise for over two month presence of molten steel and extinguish proof fires beneath the WTC 7 rubble?
 
Clayton Moore said:
So what's the explanation of your area of expertise for over two month presence of molten steel and extinguish proof fires beneath the WTC 7 rubble?
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Your fantasy. You sure pick the easy questions. You have or believe the big lie of melted steel. You picked the wrong side, you picked the crazy claims on 911 movement which spreads lies, and they call themselves "truth". Ironic, you were fooled.
 
Clayton Moore said:
So what's the explanation of your area of expertise for over two month presence of molten steel and extinguish proof fires beneath the WTC 7 rubble?
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Easy explanation.

You're fabricating it. If it didn't exist, it needs no explanation. You might as well whine about the elephant crap under the rubble.

Neither of them existed.
 
Tony Szamboti said:
Okay, I bit and watched your video.

However, it isn't the responsibility of individual citizens to perform an investigation which affects the public. The government is responsible to perform a fully resourced investigation and provide a sound explanation. The first investigation has been shown to be incorrect due to its explanations having impossibilities contained within them. The government needs to do it over. There is no need for yours or my donations there as we already contribute via taxes.
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Whatever happened to the demand for an independent investigation? I thought you believed the government was "in on it". Wouldn't allowing them to investigate create a perfect excuse to dismiss it?
 
Clayton Moore said:
So what's the explanation of your area of expertise for over two month presence of molten steel and extinguish proof fires beneath the WTC 7 rubble?
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Controlled demolition at a landfill:

In early November 1999, at the Delta Shake and Shingle Landfill in North Delta, British Columbia. the fire burned between 20 and 30 metres (about 100 feet) deep. On November 27, Delta's Mayor declared a state of local emergency. Extinguishing the fire took slightly more than two months and cost more than $4 million (Canadian).
​
http://en.wikipedia.org/wiki/Landfill_fire#Notable_landfill_fires

Millenium-old controlled demolition at a coal mine:
The fire burns 30 metres underground, moving at the slow rate of one metre south every year. The lack of oxygen underground means the fire burns slowly, and with 6 km of burnt area, the fire is estimated to be about 5,500 years old.
​
http://www.abc.net.au/science/news/enviro/EnviroRepublish_786127.htm
 
Clayton Moore said:
So what's the explanation of your area of expertise for over two month presence of molten steel and extinguish proof fires beneath the WTC 7 rubble?
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*facepalm*

That isn't my area of expertise, but then again, it doesn't need to be.

Clayton, as others have pointed out, unless you can demonstrate that molten steel and inextinguishable fires were present beneath the WTC 7 rubble for over two months, there is nothing to explain.

If you manage to refer to a phenomenon that can actually be demonstrated, then your next task is to explain why you think CD provides a helpful explanation. In your no doubt extensive experience, does CD commonly produce molten steel and inextinguishable fires beneath the rubble for over two months? Is that a bug, or a feature of "controlled" demolition? If you have anything actually useful to say about this topic, by all means, there is no need for you to hold back.
 
Tony Szamboti said:
Well you will have to take your seriousness on this somewhere else because I think it is a joke. Have a ball.
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There are two very simple things I am pointing out in my video. So simple, even a caveman can do it.

But should I be surprised about your reaction to my video? No.

Truthers watch this video, say it's a joke, but then turn around and flap their gums about 9/11 being an inside job. Even after their silly claims have been debunked for years, they still say the same thing.

So gee Tony, who's really telling the joke here?
 
leftysergeant said:
The floor slabs and trusses, deprived of support in the center of the building, pulled the exterior columns inward, as was seen in the towers. They were unable to support the weight, and snapped in such rapid succession as to be almost instantaneous. No big mystery.

There is, however, no evidence of any other cause that any rational person can think of.
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The NIST sim shows that the north face buckled outward at approx the 8th floor. IIRC this is due to the northern most coulmns of the core also being the southernmost columns under the cantilever trusses. The core gets progressivley destroyed damaging these trusses until the fail. these columns carried a large percentage of the load on the cantilever trusses, the columns within the Con-ed station were not sufficient to take the increased load and those trusses then tilted downward at their southern end quickly failing the Con-ed columns by buckling. The northern most columns under the trusses were the largest under those trusses and failed last and by this time the 40 storey mass above is beginning to move downward, pushing on the tilted trusses which causes the northern columns below 8th floor to buckle to the north. All columns under the 8th floor are so far from vertical that they contribute zero structural support (so-called truther 'resistance") and all they do to affect the fall of the 40 storey mass is due to transfer of momentum. The 40 storey mass is moving while the mass below is stationary The masses merge and therefore by CoM (MV=m1v1 +m2v2 in its simpliest form) the velocity of the total slows. However given that at best the mass at zero velocity is 20% of the moving mass this has little effect AND all of the mass is still under the influence of the force or gravity and will continue to acellerate.

Furthermore we have the effect of viewing a structure moving in 3 dimensions on a 2 dimensional representation, optical effects may contribute to what is measured. Adding to this are rotational effects that can cause objects to be acellerating at greater than g.


So despite all of this the 911 conspiracy movement insists that the video measurements of FFA(+) can only be explained by the simplistic invocation of explosive demolitions simultaneously of all columns.

To that arguement however one notices a few thing
- that explosives the size required to simultaneously blow all the columns would absolutly require enormous sounds of explosives that simply were not present.
- even if they were, the upper storeys could only fall a few inches or feet until encountering the mass of the structure below the charges(unless we now also invoke more changes on every floor below the 8th) at which point we would then also see an effect due to CoM. The fact this effect is not seen means that in either a gravity alone or explosive demolition this effect will not be seen.
- the conspiracists then attempt to invoke thermite to quell the arguement about no explosive sounds. The problem with this is that thermite burning not only has telltale extreme light but is also nigh on impossible to time accurately accross all columns in the building.
- next comes the idea that thermite can be made to be explosive but this is really a stupid idea since no matter what is used in the way of explosives it will still have to produce a shockwave and very loud boom.

Then there is Clayton's textbook example of handwaving; that (unproven) molten metal(supposedly steel) and long lasting fires under WTC 7 prove CD. This is an Olympic sized leap of intuition backed up by little to no evidence.
 
MarkLindeman said:
*facepalm*

...............If you manage to refer to a phenomenon that can actually be demonstrated, then your next task is to explain why you think CD provides a helpful explanation. In your no doubt extensive experience, does CD commonly produce molten steel and inextinguishable fires beneath the rubble for over two months? Is that a bug, or a feature of "controlled" demolition? If you have anything actually useful to say about this topic, by all means, there is no need for you to hold back.
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Indeed such a claim would require at least one example of a CD performed on an office structure that had not had all of its office equipment and furnishing removed, something that simply never occurs. Thus given that in known CDs such fires cannot occure (all flammables having been removed prior to take-down) claiming that underground fires prove CD is the ultimate in illogic.
 
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