The NIST report, start to finish

Originally posted by exponent
I'm not demanding NIST is correct, but I have yet to see many serious challenges for their investigation. Even the best I have come across tend to be quite trivial, nobody has come together to actually set out experimental criteria that I know of.

Are we forgetting that NIST had to change their WTC7 report to include the 2.8 second freefall that was pointed out to them by a critic?

• WTC workstations would readily burn and produce temperatures significant enough to damage steel

Please physically prove this.

These temperatures were maintained for a long enough period to affect the steel

Please physically prove this.

Steel with damaged insulation would heat up very quickly

I agree. But to what extent was the "cementaceous" insulation and not just the "spray on" insulation damaged?

Insulation damage was very likely

You mean at the points where Prudue showed the plane slicing through core columns? After being shredded from slicing through outer columns? That same type of "very likely"?

Originally posted by Nutter
Not all the information is there to perform an actual finite element analysis. What about the professional groups who want to study a building that is not even in existence anymore? Nope, natonal security.

That's my problem with this whole "investigation". The secrets.

It's quite likely that if there's an academic reason to carry out an investigation they won't have much of a problem getting hold of the information. There's a fairly large difference between a university team and a truther group investigating.

Having said that, I don't see why the information on WTC1/2 shouldn't be made public, after all the buildings have been destroyed as you said.

Are we forgetting that NIST had to change their WTC7 report to include the 2.8 second freefall that was pointed out to them by a critic?

No, NIST had to add some extra labels in, that was about the sum of the change.

Please physically prove this.

You requested this for the first two points, that fire would readily heat up and stay that way for some time. For that I give you the results of the Cardington fire tests and NISTs fire tests:






As you can see, fires quickly reach > 800c and stay there for a while, and uninsulated steel will follow that curve delayed by a few minutes.

I agree. But to what extent was the "cementaceous" insulation and not just the "spray on" insulation damaged?

I doubt plasterboard survived hugely well, but from NISTs tests it likely performed quite a lot better than the spray on insulation. That tended to suffer adhesion rather than cohesion failure.

You mean at the points where Prudue showed the plane slicing through core columns? After being shredded from slicing through outer columns? That same type of "very likely"?

I'm not sure what this means. I'm talking about from plane impact. NIST did a bunch of tests with debris at similar energies (same order of magnitude) and they were easily able to separate whole chunks of fireproofing. In fact there are reports that it could be knocked off by accident when installing utilities.

Thanks very much for engaging, hopefully my answers are not too brief, let me know what you think.

I doubt plasterboard survived hugely well, but from NISTs tests it likely performed quite a lot better than the spray on insulation. That tended to suffer adhesion rather than cohesion failure.

Quite a lot better? Better enough to insulate from a fire for less than an hour maybe? Maybe that is why the huge emphasis on "spray-on" fire insulation? Who knows...maybe a different thread.

I'm not sure what this means. I'm talking about from plane impact. NIST did a bunch of tests with debris at similar energies (same order of magnitude) and they were easily able to separate whole chunks of fireproofing. In fact there are reports that it could be knocked off by accident when installing utilities.

So, why haven't the companies that perform the adheasion testing on the insulation been brought to justice then? If it was falling off then it was not properly applied and/or kept up with yearly inspections (again....where's the court cases for fraud?).

Thanks very much for engaging, hopefully my answers are not too brief, let me know what you think.

No problem and I'll stay as long as the conversation remains civil. Thank you.

Originally posted by Nutter
Quite a lot better? Better enough to insulate from a fire for less than an hour maybe? Maybe that is why the huge emphasis on "spray-on" fire insulation? Who knows...maybe a different thread.

I would say almost certainly better. I don't exactly have a huge amount of experience but I've smashed plenty of drywall in my time and it almost always came apart in pieces, rather than being detached from the walls. The problem is estimating it reliably, obviously crashing a plane into something is a highly dynamic event, and it's not something that can be reproduced easily.

So, why haven't the companies that perform the adheasion testing on the insulation been brought to justice then? If it was falling off then it was not properly applied and/or kept up with yearly inspections (again....where's the court cases for fraud?).

The problem with trying to hold people to account is that you have to assume they were required to consider high energy impact as part of the design criteria. If the fireproofing was so bad that it was below standard, then of course I have no problem with someone being held responsible. The difficulty is in assigning blame when at the time the best simulation methods they had were relatively primitive, and nobody had considered this sort of terrorist attack in detail.

No problem and I'll stay as long as the conversation remains civil. Thank you.

I am interested in whether you consider the graphs of the various fire tests to be sufficient evidence for the first two points. I figure that this topic has had nearly enough time to garner comments and if we can resolve any questions about the last two points we can move on to the more contentious ones.

Originally posted by exponent
I am interested in whether you consider the graphs of the various fire tests to be sufficient evidence for the first two points. I figure that this topic has had nearly enough time to garner comments and if we can resolve any questions about the last two points we can move on to the more contentious ones.

I have no problem with the evidence you put forth. We can agree on those two points.

I was thinking you were going somewhere else with those points. My mistake.

reply to post by Nutter


Here is a link to the office and fireproofing tests.

www.nist.gov...

The building code in 1968 required that in case of a fire the structure should last 2 hours which would be sufficient time to evacuate, so the engineers attempted to do their job and succeeded for the most part. The testing was done to show how this could have occurred and not the why.

All four WTC floor system fire tests used the standard procedure known as ASTM E119 for rating the fire resistance of a building structural unit such as a floor system, column or beam under prescribed conditions. The tests were conducted as part of a NIST contract at the two separate UL fire test laboratories to take advantage of the different capabilities available at these facilities.
The first two tests, conducted in early August 2004 at the UL facility in Toronto, Canada, looked at the fire performance of 11-meter (35-foot) floor systems coated with a near-uniform 19-millimeter-thick (0.75-inch) layer of fireproofing material. This is representative of the span size and as-applied average fireproofing thickness of the floor systems in the WTC towers.
One floor system in the Canadian tests was restrained (prevented from expanding due to thermal conditions) while the other was not. Understanding the impact of restraining or not restraining the WTC floor systems during ASTM E119 testing is important. Floor systems tested under ASTM E119 traditionally have been restrained; however, the novel design of the floor systems in the WTC towers did not qualify as either fully restrained or fully unrestrained.
Past experience with the ASTM E119 test method would lead investigators to expect that the unrestrained floor system would not perform as well as the restrained assembly, and therefore, it would receive a lower fire rating. The Canadian tests actually yielded the opposite result: the restrained WTC floor system was fire rated at 1.5 hours while the unrestrained floor system was rated at two hours. NIST investigators will consider this difference when evaluating the performance of the actual WTC floor systems.
For the two experiments at UL in Illinois, 5-meter (17-foot) truss spans—the standard size used in U.S. fire resistance tests—were built. Both were restrained. The test on Aug. 19, 2004, was conducted on a floor system with a fireproofing thickness of 19 millimeters (0.75 inch), the same as the 11-meter assemblies tested in Canada. The test on Aug. 25, 2004, used a 5-meter truss with a fireproofing thickness of 13 millimeters (0.5 inch). This was the thickness of the truss fireproofing originally specified when the WTC towers were built. Therefore, if an ASTM E119 fire resistance test had been conducted on the WTC floor system prior to construction, these would have been the test conditions. NIST has no evidence or record indicating that such a test was ever done.
A fire rating of two hours was determined from the Aug. 19 test with the “as-installed” (19 millimeters) fireproofing thickness. This matches the 1968 New York City building code rating for floor systems in Construction Class IB buildings (the designation assigned to the WTC towers when they were built). A fire rating of 45 minutes was determined from the Aug. 25 test with the “as-specified” (13 millimeters) fireproofing thickness.

During the testing, it was found that some of their original thoughts were incorrect not about 9/11 but the structure rating which was part of the recommendations that were put forth when NIST completed its investigation.

If you would like to see the results, please follow this link.

www.nist.gov...



And here is where they test the office space...

www.nist.gov...

Here is a video that was taken after the 93 bombing...shows the fireproofing on lower and the 84th floor.

www.youtube.com...

Originally posted by Nutter
I have no problem with the evidence you put forth. We can agree on those two points.

I was thinking you were going somewhere else with those points. My mistake.

Excellent, the next points were:

• Steel with damaged insulation would heat up very quickly
  
• Insulation damage was very likely

I believe that the former can be shown by the graph from the Cardington tests in which unprotected steel rapidly heated.

The latter however is very difficult to discuss, and even harder to come up with good arguments for or against. NISTs tests on this were quite simple, they shot nuts, bolts, washers and varying other metal objects at steel plates and bars with kinetic energy that would be expected from the aircraft impact.

This produced ready failure of fireproofing, and as NISTs only tests were direct impact, they assigned fireproofing loss in their model to only the areas where the plane would have damaged or destroyed the office contents + partitions.

This seems a perfectly reasonable way to implement fireproofing damage, and so I look forward to any criticism you have of it.

Originally posted by exponent
I believe that the former can be shown by the graph from the Cardington tests in which unprotected steel rapidly heated.

Unlike the Cardington tests though, the entire steel was not heated and also not for the total duration. As you can see from your graphs, once heat is no longer applied the fire temp and steel temp rapidly cools.

But, on the whole, I agree with your statement.

This seems a perfectly reasonable way to implement fireproofing damage, and so I look forward to any criticism you have of it.

I really can't think of any other reasonable way to perform it other than the real thing, so I will agree.

Originally posted by exponent

As you can see, fires quickly reach > 800c and stay there for a while, and uninsulated steel will follow that curve delayed by a few minutes.

This is the problem with the NIST report. They give you lots of data that may well be correct.

But under WHAT CONDITIONS is it correct?

If you are dealing with an H-Beam 36 feet long made of 1 inch thick steel and only 12 feet of the beam are in the fire then how is the temperature going to behave. And if the beam is connected to 6 other beams at 12 foot intervals what is the effect. But then we are not told how many TONS OF STEEL were on the 81st floor of the south tower where the fire occurred but we are suppose to BELIEVE these temperature graphs.

It's that old, "Figures don't lie but liars figure". Just because data is good does not mean it is relevant to a particular situation.

For all we know that test could have been done with a 50 lb piece of bare steel.

Steel is 490 lb per cubic foot. So an H-Beam 4 feet long made of 1 inch thick steel with the flanges and web 1 foot wide would be 490 pounds. So a 36 foot section of column would be 2.25 TONS. Do you really believe that much steel is going to reach 1000 deg C in 60 minutes under uncontrolled conditions?

psik

Originally posted by psikeyhackr
This is the problem with the NIST report. They give you lots of data that may well be correct.

But under WHAT CONDITIONS is it correct?

If you are dealing with an H-Beam 36 feet long made of 1 inch thick steel and only 12 feet of the beam are in the fire then how is the temperature going to behave. And if the beam is connected to 6 other beams at 12 foot intervals what is the effect. But then we are not told how many TONS OF STEEL were on the 81st floor of the south tower where the fire occurred but we are suppose to BELIEVE these temperature graphs.

That figure was actually from Cardington, and so the information for that graph is quite easily accessible through here.

You do have a point though, in that the performance of steel obviously differs depending on its geometry. NIST does provide quite a lot of detail on this. I'm not sure why you expect them to provide some sort of tabulated 'tons of steel per floor' figure, but as I have already pointed out Gregory Urich has produced a list from the various datasources available that should be more than accurate enough for any simulation you have in mind.

The complexity of steel and fire interaction is a good point to make too, because this is what forced NIST to resort to computer modelling to explain the collapses. There were so many elements involved in so much activity for a particularly long time (in terms of structural simulation).

Steel is 490 lb per cubic foot. So an H-Beam 4 feet long made of 1 inch thick steel with the flanges and web 1 foot wide would be 490 pounds. So a 36 foot section of column would be 2.25 TONS. Do you really believe that much steel is going to reach 1000 deg C in 60 minutes under uncontrolled conditions?

You've already told us the vital information needed other than the thermal conductivity of the steel. The calculations to find this out are not particularly difficult, so you can answer your own question. I've done calculations like this before though and usually it doesn't satisfy the argument, so I'd like you to pick your own values and see what result you get.

Originally posted by exponent
You do have a point though, in that the performance of steel obviously differs depending on its geometry. NIST does provide quite a lot of detail on this. I'm not sure why you expect them to provide some sort of tabulated 'tons of steel per floor' figure, but as I have already pointed out Gregory Urich has produced a list from the various datasources available that should be more than accurate enough for any simulation you have in mind.

The complexity of steel and fire interaction is a good point to make too, because this is what forced NIST to resort to computer modelling to explain the collapses. There were so many elements involved in so much activity for a particularly long time (in terms of structural simulation).

I have already contended with Gregory Urich.

He admits that he had to do an interpolation of the perimeter wall panels even though he claims to have gotten data from the SAP2000 database from the NIST. Now what sense does that make?

But his interpolation is linear and based on the assumption that the bottom wall panels were 19 tons even though we have an article from 1970 saying the heaviest panel was 22 tons. But he can't use 22 tons for a linear interpolation because that would result in negative weight panels at the top of the building. NOT GOOD!

But why is the nation that put men on the Moon depending on a Swedish computer programmer for data. Why aren't structural engineers in the US providing it. That is very curious in itself. And why doesn't Lon Waters have horizontal beam data for the core after all of these years? Is that missing too?

wtcmodel.wikidot.com...

It is strange that he would do all of that work to show core column cross sections and then not have the beams. What does the NIST say about those beams?

Didn't the Cardington test deliberately create a fire all over the structure simultaneously and therefore was it not CONTROLLED CONDITIONS. Wasn't the Cardington structure only EIGHT STORIES high. How thick was the steel?

The steel at the 81st level of the WTC had to support another TWENTY NINE STORIES.

How thick was the steel? So how could it give way in less than ONE HOUR?

That has been the thing about 9/11. The more I study it the more obviously STUPID it is. So how have our engineering school managed to be mostly silent about this for NINE YEARS. As for as I have seen I am the only person to point out that the core columns don't move due to the impact in the Purdue simulation. But not to many people claim I am wrong either.

One idiot said the mass of the building didn't matter just the stiffness.

psik

reply to post by psikeyhackr


If you would like a copy of the blueprints, please send me a message and I can send them to you. This may help you with your questions.

Originally posted by esdad71
reply to post by psikeyhackr

 

If you would like a copy of the blueprints, please send me a message and I can send them to you. This may help you with your questions.

I have seen blueprints of the core. They show the positions of all of the toilets.

Do you have blueprints that show the positions of the horizontal beams that connected the core columns. If you do then yes, I would like to see them.

psik

reply to post by psikeyhackr


Here, you can go download them if you like. If you know how to read a blueprint this should do it for you. It was released and sent to Steven Jones and it then hit the internet.

www.megaupload.com...

or

911research.wtc7.net...

This is for the WTC 1. I have the WTC 2 but they are not uploaded as they are larger.

Toilets huh? Is that the only thing you could determine from them.

Originally posted by esdad71
reply to post by psikeyhackr

 

Here, you can go download them if you like. If you know how to read a blueprint this should do it for you. It was released and sent to Steven Jones and it then hit the internet.

www.megaupload.com...

Yeah, it's the usual crap I have seen before and before and before.

It is quite clear in the file 083_49th Floor Core Plan.tif You can see 8 columns that look like there is absolutely nothing linking them to the other columns. There is not data on the horizontal beams that were on every level. That is why Lon Waters' site has detailed info on the columns and nothing on the beams.

BELIEVERS don't accept that we don't have the information to analyze the problem. They just repeatedly say, "It's there, It's there." "You're just stupid!" "You're just lazy". BLAH, BLAH, BLAH.

PHYSICS WITHOUT DATA. RIDICULOUS!

psik

reply to post by psikeyhackr


You raise an awful lot of points here, and I'm not going to disagree with any of them particularly. Yes the data NIST released is not ideal, but you can hardly expect them to bend over backwards for you.

I'm interested in exactly what sort of analysis you're doing where you need this level of accuracy.

I still want to discuss those 4 points.

Is there anything in the entire NIST Report which describes in detail the actual occurance and dynamics of the destruction of the twin towers of the world trade center after the point of "collapse initiation" or in other words, did they address the actual "collapse" and destruction of the towers itself..?

Originally posted by exponent
reply to post by psikeyhackr

 

You raise an awful lot of points here, and I'm not going to disagree with any of them particularly. Yes the data NIST released is not ideal, but you can hardly expect them to bend over backwards for you.

I'm interested in exactly what sort of analysis you're doing where you need this level of accuracy.

I still want to discuss those 4 points.

You're just making excuses for NIST.

What else is there to discus, your four points have been covered?

How about disusing one that is actually relevant to what happened?

How do you think the towers collapsed?

And I don't mean the NIST story of how the collapse was initiated, but the actual collapse. Can you do this using the laws of motion, that are applicable?

I want to know if you're as confused as esdad, hooper etc.. who seem to think the laws of motion are only one part of the physics, that mass and KE are not covered by the laws of motion, and other confused nonsense.

Your four points are irrelevant, as I explained, they prove nothing either way.

Originally posted by NewAgeMan
Is there anything in the entire NIST Report which describes in detail the actual occurance and dynamics of the destruction of the twin towers of the world trade center after the point of "collapse initiation" or in other words, did they address the actual "collapse" and destruction of the towers itself..?

This would have to be two separate discussions about the north and south towers.

The top 29 stories of the south tower breaking loose and tilting more than 22 degrees in less than 4 seconds is probably the most phenomenal event to occur to a man made object in history.

For our engineering schools to not be all over that like white on rice is simply criminal.

www.youtube.com...

www.youtube.com...

And yet the building only deflected 15 inches when the plane impacted at 550 mph.

So these to contradictory events are the clearest simple evidence that something else was involved that I know of.

psik

reply to post by psikeyhackr


That's interesting but it didn't answer the question..