NIST report incorrect?

[Crungy]

I have a connection to Bathtub Boy. I work for a company that Aquaboy slandered in his post. I have a interesting story that I'll filter through CT lenses. After the 9/11 attacks my firm received a large contract to provide security for a major urban water delivery complex and filtration plant. We have already been working with this client prior to 9/11. One of my tasks was to design a various diesel generator systems to provide backup power.

One of the structures required a custom built field assembled 3000 gallon diesel fuel storage tank. Typically, when I design an outdoor above ground tank, it's prefabricated (ConVault and Highland Tanks being two manufacturers I've used in the past) and UL 142 stamped at the factory. The UL rating insures welding integrity and welding procedures and tank impact resistance to bullets and aircraft.

For this project, the tank was to be built in an room with irregular geometry, located on a lake structure. In my job specifications, I wrote out that the field built tank was to be stamped with a UL 142 rating. When the job got rolling, the mechanical sub-contractor sent me a RFI (request for information) stating that his tank manufacturer UL would not certify the field built tank. What should he do? Let's see Kevin Ryan, who worked for a division on UL gets fired for remarks about the 9/11 investigation, remarks that cast suspicion and mistrust on my company and a fellow co-worker. Now UL won't certify my 3000 gallon field built fuel tank for a project, which was brought on by 9/11. Sounds pretty damn suspicious. A conspiracy perhaps? Did I get shut down because Aquaboy was able to pull strings with his old UL pals. With all of the above "suspicious connections" and conflicts of interest, a CTer might think so. Being of sound mind, I new that the UL 142 standard was only done in tank factories and certified the tank upon completion, thus protecting the tank manufacturer from any potential litigation if the tank were to be damaged during transport.

This type of slander, which I've seen Aquanut engage in the several times I've read or watched his nuttery, is what really irks me. Like many nutters, prior to laying out his nonsense, H2Wooboy will attempt to discredit any person or firm due to them having any history working with "The Man". Once you get in the business, it's harder to find any person or company who hasn't at one time worked on a project involving "The Man". Anyone in the business world knows this as a given. Anyone on the "Elite (WTC, Pentagon, Shankville, Wonka Factory, etc) Team" will be oblivious to this for life. Employees aren't speaking out for fear of reprisal. If you walked in my office, you'd see plenty of cubes decorated with anti-Bush material. They aren't speaking out because they are professionals in the design and construction industry and their expertise is in concert with those of their peers, those which shaped the OS. They view the technical counter arguments of Ryan and his ilk with the same level of exasparation as a surgeon does the critique of a witch doctor.

Sorry for the rant, but this reckless sort of character assassination was personal and way, way off the mark. I'm sure I'll be labeled a shill by some.

 

[rwguinn]

NIST's explanation explicitly determines that the floor assemblies DID NOT collapse. Indeed, their explanation is only possible if the floor trusses remained intact.

It seems to me very few people actually understand the details of the NIST collapse sequence. Kevin Ryan appears to be one of them.

Also, anyone else pick up the alleged 2000% load redundancy of the exterior columns? I aren't a mechanical engineer, but that one's setting off all my BS meters.

Anyone care to calculate the realities of a 2000% structural redundancy?

-Gumboot

Redundant=capable of operating with 100% system failure.
The control system in an F-16 is doubly redundant-the old tell-me-3-times. if one system craps out, the other 2 out-vote it and take over. The mssion continues
The term we use is Factor of safety (FS). generally, it is between 2 and 5. That means the system can withstand between 2 and 5 times the expected maximum load with all the structure intact!
With damage to the structure, all bets are off. Load paths have changed, and those FS are no longer valid.
Is that correct, Archetect, et al?

 

[uk_dave]

I would say that the principle of redundancy in a building is the avoidance of disproportionate collapse.

Disproportionate collapse is where the building fails when the damage is actually not severe or is totally predictable.

Therefore a building in an earthquake zone would have to survive a reasonably predictable earthquake whereas a building not troubled by such considerations does not have to have the same design criteria.

In the case of the wtc towers it's a fairly simple engineering design process to calculate what threat these tall buildings will face and what redundancy can be built in to counter this threat.

The obvious threats are:

Earth
Wind
Fire
and aircraft strike. (just kidding about the 'earth' part....unless we take that as meaning earthquake )

It is not unrealistic to consider that even if all of these events are within the design tolerances of the building, an event which inlcuded a hurricane, earthquake, electrical fire and a strike by an aircraft is going to lead to total failure of that building!

Of course that is an exagerrated scenario, but the point I'm making is that designing against disproportionate collapse means taking educated guesses as to what damage will be caused to the structure in any predictable event.

If the actual damage exceeds the design, such as on 911, then the building will fail.

Designing for redundancy is expensive and the designers and developers are going to want to establish a parameter for this design which still enables the building to be constructed economically.

 

[Sword_Of_Truth]

To say 9/11 was an inside job, because such events never happened before, is like saying Charles Lindbergh could not have crossed the Atlantic, because it never happened before.

By that same reasoning the WTC collapse was faked because no building has ever been collapsed with thermite or ray guns before. Not once... ever. Yet on 9-11 it miraculously occurred 3 times!

This was an obvious "false flag" op by Al-Queada to provoke a war of stupid between internet a__holes and the Bush administration by cleverly ramming a couple of airplanes into a couple of office towers in such a way as to mimic a thermite/ray gun induced collapse.

 

[The Almond]

Factors of Safety are determined from a combination of Dead Loads (building weight) and Live Loads (furniture, people, wind, seismic, etc). Say you want to determine the size of a column. Under the Load Factor Resistance Design (LRFD) method, the required loading requirements may look something like:

F = 1.4 DL + 1.8 LL + 1.5 (Wind Load)

I keep forgetting when LFRD was actually put into place. When I was doing structural design classes, we called it the Strength Design method using LFRD, the other method was called Allowable Stress Design method based on factors of safety. Strength Design was a slightly newer design method where you used load factors, but Allowable Stress was the older one where you use a factor of safety and essentially design a column, beam, etc about 3 times stronger than it needs to be.

My point is that I don't know if the towers used LFRD in the design or not, but there's no way anyone used a factor of safety above 6 in any part of the design. That's just silly.

The term we use is Factor of safety (FS). generally, it is between 2 and 5. That means the system can withstand between 2 and 5 times the expected maximum load with all the structure intact!
With damage to the structure, all bets are off. Load paths have changed, and those FS are no longer valid.
Is that correct, Archetect, et al?

That's correct in theory, but no engineer designs a structure in order to account for columns that may not be there, only for loads that are greater than predicted. Basically, there's no logical reason to assume that the columns aren't going to be there for the life of the building.

 

[rwguinn]

I keep forgetting when LFRD was actually put into place. When I was doing structural design classes, we called it the Strength Design method using LFRD, the other method was called Allowable Stress Design method based on factors of safety. Strength Design was a slightly newer design method where you used load factors, but Allowable Stress was the older one where you use a factor of safety and essentially design a column, beam, etc about 3 times stronger than it needs to be.

My point is that I don't know if the towers used LFRD in the design or not, but there's no way anyone used a factor of safety above 6 in any part of the design. That's just silly.

Design was in the 60's. We were still sing Safety Factors in school in the 70's...

That's correct in theory, but no engineer designs a structure in order to account for columns that may not be there, only for loads that are greater than predicted. Basically, there's no logical reason to assume that the columns aren't going to be there for the life of the building.

er---tat's what I thought I said...
If it was subject to different interpretation, I need to fix my language...

 

[PerryLogan]

To say 9/11 was an inside job, because such events never happened before, is like saying Charles Lindbergh could not have crossed the Atlantic, because it never happened before.

(Quoting Bell.)

And there's an added layer of absurdity on top of this--i.e., no one trying to perpetrate a hoax would make it an unprecedented, anomalous, impossible event, for the very good reason that this would tend to give away the plot.

You will notice the Truthers just don't get this, bless their hearts. The more mindblowing anomalies they find in the 9/11 story, the less likely it is that 9/11 was a conspiracy.

This means the 9/11 Truthers are diligently debunking themselves again and again, but are too stupid to know it. Hilk!

 

[patchbunny]

I keep forgetting when LFRD was actually put into place. When I was doing structural design classes, we called it the Strength Design method using LFRD, the other method was called Allowable Stress Design method based on factors of safety. Strength Design was a slightly newer design method where you used load factors, but Allowable Stress was the older one where you use a factor of safety and essentially design a column, beam, etc about 3 times stronger than it needs to be.

Yeah, I remember using both methods, but I'll be damned if I can remember when it came into play either. Been a looong time.

And I resent the fact I can now saw that about points of my education.

My point is that I don't know if the towers used LFRD in the design or not, but there's no way anyone used a factor of safety above 6 in any part of the design. That's just silly.

Indeed.

 

[Garb]

Thanks for your input guys. I really appreciate it.