Steel failing in hydrocarbon fires.

[Dave Rogers]

And what you call a "close estimate" of fuel loads was admittedly a "mild overestimate." NIST overestimated because more realistic fuel loads wouldn't get the WTC 7 to collapse. Therefore, computer models came in handy to tweak the data and arrive at the desired result.

Nothing but crickets. RedIbis, failure to post a source for this assertion will henceforth be taken as an admission that it was a deliberate lie.

Dave

 

[jaydeehess]

http://www.internationalskeptics.com/forums/showthread.php?postid=5181288#post5181288

RedI has had all of this pointed out to him before and chose to ignore it then as now.

I asked you a page or two back what physical evidence would have sufficed for you? Col/79 itself? What would that do? The floor beams that pushed the girder? The girder itself? How would you identify them?

So you already KNOW that the evidence YOU require simply could (not would) never be available and you are using that to try to say that the computer sims are fudged.

NIST gives the calculations on the expansion of the beams. One could, with enough time on their hands, verify them, and then go on to verify that this would have beenm enough to push the girder off its seat. One could also verify that the collapsing floor would take out other floors. So tell me Red, how many floors COULD be safely removed (violently or otherwise) before col 79 buckles due to loss of lateral support?

Surely the brain trust at AE911 have done the calculations, have they not?

Oh, but you then doubt that taking out col 79 could possibly lead to a progressive collapse of the entire structure!

This is an arguement with what science backing Red? AE911 has done their own sim on this and shown that the structure would only fail locally, right?
NO??? I wonder why not? Money? Architects and Engineers, for that matter Lawyers, or pilots, all make good money yet none of them in their "... for 911 Truth" groups has raised anything to conduct any such research.

 

[dtugg]

RedIbis a liar? No way.

 

[BenBurch]

RedIbis a liar? No way.

 

[RedIbis]

Nothing but crickets. RedIbis, failure to post a source for this assertion will henceforth be taken as an admission that it was a deliberate lie.

Dave

Yeah ok, it's not like I have a life and have to do other things than post all day. The good news for you is that you get to plan a huge party and invite all of your favorite debunkers because I was inaccurate.

NIST did overestimate fuel loads, but they admitted to mildly overestimating burn duration.

This is obviously a huge gaffe and you should probably focus on it rather than have to confront the reality that NIST had to overestimate burn durations to get their computer models to simulate collapse.

I suspect you and your cohorts will continue to post more laughing dogs, call me silly names and yuk it up like schoolboys, but what you won't do is ask me for a source this time because you probably already know that this is accurate.

 

[BigAl]

Yeah ok, it's not like I have a life and have to do other things than post all day. The good news for you is that you get to plan a huge party and invite all of your favorite debunkers because I was inaccurate.

NIST did overestimate fuel loads, but they admitted to mildly overestimating burn duration.

Cite, please.

 

[DGM]

Yeah ok, it's not like I have a life and have to do other things than post all day. The good news for you is that you get to plan a huge party and invite all of your favorite debunkers because I was inaccurate.

NIST did overestimate fuel loads, but they admitted to mildly overestimating burn duration.
This is obviously a huge gaffe and you should probably focus on it rather than have to confront the reality that NIST had to overestimate burn durations to get their computer models to simulate collapse.

I suspect you and your cohorts will continue to post more laughing dogs, call me silly names and yuk it up like schoolboys, but what you won't do is ask me for a source this time because you probably already know that this is accurate.

Could you source this for me?





Damn!!!! BigAl beat me to it.

 

[RedIbis]

Cite, please.

NIST NCSTAR 1-9 p. 383

 

[RedIbis]

RedIbis a liar? No way.

Drunk again?

 

[BigAl]

NIST NCSTAR 1-9 p. 383

Assuming you are speaking of this publication, the page numbers don't go that high and if you are looking at the page # shown in acrobat, it doesn't say anything like what you claim.


http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR 1-9 Vol 1.pdf

 

[Dave Rogers]

Yeah ok, it's not like I have a life and have to do other things than post all day. The good news for you is that you get to plan a huge party and invite all of your favorite debunkers because I was inaccurate.

Well, it's good of you to admit you were wrong so graciously.

NIST did overestimate fuel loads, but they admitted to mildly overestimating burn duration.

Did you mean "did not overestimate fuel loads"? I know it's difficult to tell the truth, but since you've tried so hard I think you deserve a little help.

So, if NIST overestimated burn duration but didn't overestimate fuel loads, that means that they underestimated the rate at which the structure was heated, but calculated the heat energy supplied to the structure correctly. What effect would that have? Firstly, if the rate of heat loss was correct, then the peak temperature would have been lower. Secondly, if the heating rate was lower, then the thermal shock on the structure would be less. Overestimating the burn time, therefore, makes the building less likely to collapse, not more.

ETA: I've found the page. Let's see the actual quote, shall we?

The Floor 11 fires were represented by the floor 12 fires delayed by 1h. This resulted in a westward fire spread rate along the north face that was faster and led to a burn duration that was longer than observed in the photographs. Combined, these results could have led to a mild overestimate of the heating on the north side of the floor.

A mild overestimate of the heating on one side of one floor. RedIbis, are you seriously trying to say that the conditions in WTC7 were so close to causing collapse that a very mild increase in heating of a small part of one floor would have caused collapse, and yet that it's absurd to conclude that the fire actually caused collapse? If you think that's what you mean, you must be able to see what a ridiculous position you're taking. If you don't think that's what you mean, then you don't even understand your own line of argument.

I'd also draw your attention to the word "mild". If any more proof of nitpicking were required, this would be it.

As for your assertion that:

NIST overestimated because more realistic fuel loads wouldn't get the WTC 7 to collapse. Therefore, computer models came in handy to tweak the data and arrive at the desired result.

You have no grounds for the accusation that NIST deliberately altered the input data to make the models predict collapse. This is therefore a deliberate lie.

Go on, prove me wrong with a credible source.

Dave

 

[RedIbis]

I'd also draw your attention to the word "mild". If any more proof of nitpicking were required, this would be it.

e

Lord only knows what NIST considers a "mild" estimate?

And I did not make a mistake with my previous post, NIST did overestimate fuel loads, as well. They just didn't as readily admit it.

And please drop the bluster and indignation and just have a conversation like an adult.

 

[dtugg]

Still no evidence that NIST tweeked the data in order to arrive the desired result, I see.

 

[BigAl]

Lord only knows what NIST considers a "mild" estimate?

And I did not make a mistake with my previous post, NIST did overestimate fuel loads, as well. They just didn't as readily admit it.

And please drop the bluster and indignation and just have a conversation like an adult.

Please provide a citation for that assertion. Your link to a NIST pub failed to address your point. See

http://www.internationalskeptics.com/forums/showthread.php?postid=6060397#post6060397

 

[RedIbis]

Please provide a citation for that assertion. Your link to a NIST pub failed to address your point. See

http://www.internationalskeptics.com/forums/showthread.php?postid=6060397#post6060397

Sorry for not responding when you posted that eariler. I just thought you would have figured out by now that if the link you provided was for Volume 1 then there must be a Volume 2 somewhere.

 

[Dave Rogers]

And please drop the bluster and indignation and just have a conversation like an adult.

OK. Can you please post the source for your claim that NIST deliberately adjusted the fuel levels because their initial values did not predict WTC7 collapsing?

At this point, if you'd like to join in the adult conversation, you either post a source or say "I haven't got one".

Dave

 

[BigAl]

Assuming you are speaking of this publication, the page numbers don't go that high and if you are looking at the page # shown in acrobat, it doesn't say anything like what you claim.


http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR 1-9 Vol 1.pdf

Red's assertion:

Originally Posted by RedIbis
NIST did overestimate fuel loads, but they admitted to mildly overestimating burn duration.

http://www.internationalskeptics.com/forums/showthread.php?p=6060299#post6060299​

OK. Got it.

On page 393 NIST also says they ran a simulation that underestimated fuel load with no change in results. This is "Simulation 101" to test the model for sensitivity to a range of inputs.

Page 383 contradicts Red's claim.

Page 383 says this:

The westward fire rate along the north face was moderately faster and the burn duration was longer than in the visual evidence. Combined, these effects could have led to a mild overstatement of the heating on the north side [of floors 12 and 13]"

So NIST says that if the model was wrong it "mildly" overestimated temperatures in a location far away from the bulk of the fire, the south side.

NIST didn't do that. It is a result of the model.

 

[Dave Rogers]

While we're waiting, here's something NIST NCSTAR 1A has to say that may be worthy of consideration.

Page 32:

Three different thermal response computations were used. Case A used the temperature data as obtained from the FDS simulation. Case B increased the Case A gas temperatures by 10% and case C decreased the gas temperatures by 10%.

Page 36:

The three different thermal response cases (A, B and C) were used in the ANSYS analysis. Based on the ANSYS model results, it became apparent that the calculated fire-induced damage to connections and beams were occurring at essentially the same locations and with similar failure mechanisms, but shifted in time. (Case C failures occurred at a later time than the same failures in Case A, and Case A failures occurred at a later time than Case B failures.) As a result, only the fire-induced damage produced by Case B temperatures was carried forward as the initial condition for the building collapse analysis, since the damage occurred in the least computational time (i.e., 6 months).

This makes it quite clear that NIST first checked that their model was insensitive to 10% variations in the input parameters, then used a dataset representative of all their variants to predict the failure mechanism. This is completely in opposition to the assertion that they adjusted the data to achieve a required result; on the contrary, they varied the data to confirm that their conclusions were robust. If they'd deliberately underestimated the fuel load, the collapse would still have occurred, but would have taken longer to occur.

Dave

 

[ElMondoHummus]

This makes it quite clear that NIST first checked that their model was insensitive to 10% variations in the input parameters, then used a dataset representative of all their variants to predict the failure mechanism. This is completely in opposition to the assertion that they adjusted the data to achieve a required result; on the contrary, they varied the data to confirm that their conclusions were robust. If they'd deliberately underestimated the fuel load, the collapse would still have occurred, but would have taken longer to occur.

Dave

Furthermore, if I'm reading things correctly, the initial inputs to the model did indeed predict a collapse. The "tweaking" was nothing more than what you wrote above.

 

[MikeW]

Perhaps Prof Quintiere might also be useful here. The truthers love him for criticising NIST, after all, so I'm sure they'll also take him seriously when he says "I believe the fuel loading used by NIST is in error and was too low" (for WTC1 and 2, at least), and gives his reasons.