9/11 Truth: MIT Engineer Jeff King Says WTC Demolished

Originally posted by Griff

Do you still believe this after I have explained the above? Let's see if you are actually searching for truth.

Yep.

Check Skilling's quote. He clearly is talking about the first story only. The first story didn't have the trusses found on most of the other floors. They had horizontal beam floors. So taking out these ext columns wouldn't do much since the extensive bracing in this area would let the core columns resist wind loads.

This cannot be applied to other areas.

Originally posted by Seymour Butz
This cannot be applied to other areas.

I can agree to this. But, I never said it does. It only applies to the member that we are talking about. If skilling is talking about a 20x FOS in the first floor, this can not be applied to any other members but the ones he was talking about.

So, say they calculated that the members in the upper portions were strong enough to survive hurricane winds, then those same members were designed to take that load either from bending moment (wind load) or axial load (gravity) or most likely a combination of the two.

They would have designed the members using the allowable stress. It wouldn't matter where that stress is applied in ASD.

So essentially, with no wind, those members would be far stronger to hold gravity load than when there is a hurricane going on. 20x...I doubt it. But, there was some FOS involved you can be sure of that.

Originally posted by Griff

I can agree to this. But, I never said it does. It only applies to the member that we are talking about. If skilling is talking about a 20x FOS in the first floor, this can not be applied to any other members but the ones he was talking about.

So essentially, with no wind, those members would be far stronger to hold gravity load than when there is a hurricane going on. 20x...I doubt it. But, there was some FOS involved you can be sure of that.

Now maybe you can see my point then. The 20x as strong is used by truthers to say that the collapse couldn't have initiated in the impact zone because the plane damage and heating couldn't because they're 20x stronger than needed.

Here's where I get agitated at you though. Granted, we don't have the specs. Ok, we've covered that. But when someone makes this claim and you don't step up..........

Do you have evidence that the columns weren't 20x stronger than needed, or is this a guess?
www.truememes.org...

Engineering News-Record reported in 1964 that the specially manufactured high strength steel perimeter columns had strength significantly greater than the 5 X load requirement of standard building codes, stating that "live loads on these columns can be increased more than 2000% before failure occurs."

That's probably where some truthers get the idea that the buildings were 20x stronger. 2000% = 20x.
Or is Engineering News Record, whom got that figure from Skilling, not a reliable source?
see "How Columns Will Be Designed for 110-Story Buildings", Engineering News Record, 4/2/1964 for details.

Also note that Skilling said the buildings could withstand impacts from a 707 and other sources have stated they could hold up to the collision and fires from that aircraft at 600 mph. That's faster and with much more jet fuel then the 767's were estimated to have had.

[edit on 15-5-2008 by PplVSNWO]

[edit on 15-5-2008 by PplVSNWO]

Originally posted by Seymour Butz
Here's where I get agitated at you though. Granted, we don't have the specs. Ok, we've covered that. But when someone makes this claim and you don't step up..........

I understand your agitation, but in my defense, I haven't heard of this 20x mentioned in a while. I would say the same to whomever posted it. It doesn't necessarily mean that they are dead wrong, as you've pointed out, we don't know for sure.

In NIST's defense, I do like how they have many hand written design parameters and some design from Skilling's office in their report. There is a lot of information in there when one cares to look. I admit, I haven't gone through even a fraction of it yet.

Originally posted by PplVSNWO
Do you have evidence that the columns weren't 20x stronger than needed, or is this a guess?

Skilling is talking about the first floor only. So to use this estimate to try and prove the point that the collapses shouldn't have initiated at the impact zone since they were 20x stronger doesn't apply due to different construction.

The juornal you cite is a good one. It's just that truthers selectively quote mine things out of context to try and make a point. That's dishonest, dontcha think?

Ok, how about the information that it could withstand a fully loaded 707 at 600 mph? Surely they didn't mean the tower was designed withstand a plane impact at the first floor and not the upper floors?

Also, is there any evidence that the 20x doesn't apply to all floors? We know the columns get smaller towards the top but so does the load they are holding up. Since the number of columns doesn't change, assuming the same alloy is used all throughout, it would make sense that by the top floor you would only need columns thick enough to hold up one floor or about 1/110th of the total building. It's easy to see how if the 1st floor was 2000% necessary strength, the upper floors could have been even more over-engineered.

[edit on 15-5-2008 by PplVSNWO]

Originally posted by Griff

I understand your agitation, but in my defense, I haven't heard of this 20x mentioned in a while. I would say the same to whomever posted it.

You-know-who brought it up. You know, the guy you chastised me for?

All this got me looking at the NIST again. Here:

wtc.nist.gov...

Table 5-1 says DCR is roughly .75 for the ext columns. This means that they had about a 33% safety factor? Based on worst case scenario - 100 mph hurricane?

Originally posted by Seymour Butz
All this got me looking at the NIST again.

Me too.

Here:

wtc.nist.gov...

Table 5-1 says DCR is roughly .75 for the ext columns. This means that they had about a 33% safety factor? Based on worst case scenario - 100 mph hurricane?

DCR is confusing to equate factors of safety. Because to calculate DCR, you use the allowable stress. Which is already 60% of the ultimate stress. Thus, you have already included a FOS of 40% reserve before we even begin to calculate DCR.

I could be wrong. As DCR is usually used for failure analysis and I don't analyse building failures. But, even in the equations given by NIST, they use .6Fy which is 60% of the yield strength.

But, going on. This may be where people get the 20x reserve capacity for the exterior columns. And it's from NIST's own mouth.

The allowable stress design method has an inherent factor of safety for structural components. For example, the safety factor for yielding and buckling is:

• 1.67 and 1.92 for core columns in the original design and SOP cases, and for all columns in refined NIST estimate case.

• 1.26 and 1.44 for perimeter columns in the original design and SOP case (discounting the 1/3 increase in allowable stress under wind loads).

I'll break here for a second. 1.26 when discounting the 1/3 increase under wind loads. Counting for wind loads this number would increase to 1.59.

Going on:

• After reaching the yield strength, structural steel components continue to have significant reserve capacity, thus allowing for load redistribution to other components that are still in the elastic range.

• On September 11, the towers were subjected to in-service live loads, which are considered to be approximately 25 percent of the design live loads.

Break again. Notice that the live loads on 9/11 were estimated to be 25% of the design live load. Again, more redundancy.

• On September 11, the wind loads were minimal, thus allowing significantly more reserve capacity for the exterior walls (demand on exterior columns was about 1/5 their capacity).

• The safety of the WTC towers on September 11 was most likely not affected by the fraction of members for which the demand exceeded allowable capacity.

wtc.nist.gov...

And this I believe is where people get the 20x reserve capacity from.

1/5 is 20%. It is actually in error to use 20x but it does show that the reserve capacity of the exterior columns was 4/5 the design capacity. Which is 80%.

So if the design capacity was say 100 kips, then the columns had a 80 kip reserve capacity.

Which would give a FOS of 4 not 20. But, still, 4 is a big enough number to wonder what caused the steel to initiate collapse when even the hottest temperatures quoted (that NIST analysed and found to be at max. about 600C) wouldn't cause the strength to decrease to 25%.

So, again. The specs are needed to really determine this stuff.

reply to post by Griff


So basically, NIST report contradicts itself. By giving the numbers it did, the towers should have been more than strong enough to withstand the impacts and fires, especially given there was no significant wind load. Yet, the report goes on to say they collapsed from the fire and/or impacts? Do you really need construction documents at that point?
I mean, the debunkers like to say that we don't need videos of the plane hitting the Pentagon because there is enough evidence that a 757 hit it. So, if the NIST report figures shows the towers were strong enough to not collapse, should that not be sufficient proof that the planes didn't bring them down?

Originally posted by PplVSNWO
Do you really need construction documents at that point?

Yes. How do we know that NIST is being truthful about the figures for their members?

What I mean is, they have already been shown to up computer simulations, temperature of steel and anything else that didn't jive with their pre-concieved notion that plane damage and fire were the cause. Because, well, it didn't fit their pre-concieved notion and what was "seen in the videos". What's to stop them from changing a member here and there to fit their pre-concieved notion also? Reverse engineering. Something along the lines of "oh, well that member on those drawings doesn't fit so let's change it to something that does". I'm not saying they did (as I have no clue) but neither can people say they didn't (because again they have no clue).



[edit on 5/16/2008 by Griff]

Originally posted by Seymour Butz
Now maybe you can see my point then. The 20x as strong is used by truthers to say that the collapse couldn't have initiated in the impact zone because the plane damage and heating couldn't because they're 20x stronger than needed.

Why do you always make things like this up, Seymour? Especially when you post time and again and again about "straw-men." Now I know you either don't know what a straw-man is, you're blind to your own, or you just don't know what you're saying in general. Show me where anyone made the argument you just claimed, the way you just claimed it. You don't need a FoS of 20. All you need is 2, or even 1.5, and the amount of damage we saw would not have resulted in a collapse, because the 50% or 33% of the structure you'd have to compromise to reach a factor of 1.0, was really ~

Originally posted by bsbray11
I've seen NIST generalize perimeter columns with an FoS of 5 that day (which I think is the same thing Griff is referring to above with the 1/5 capacity thing from NIST, also a figure Wayne Trumpman used in a paper where he crunches similar numbers).

Yes. As stated by NIST themselves in the link I provided.

wtc.nist.gov...

Remember that perimeter columns take about half of the gravity loads, according to NIST.

Correct again. As stated by NIST themselves:

The results of the analysis indicated that for the dead and live loads used in the original WTC design, the core columns and the exterior walls carried approximately 53 percent and 47 percent, respectively, of the total gravity load at the basement (B6) level.

wtc.nist.gov...

And before anyone says "it says at the basement level", I'll pre-emptively say that this is because the gravity load is always put on the columns to hold the building up. So, saying at the basement level just means at the foundation level. The same proportions would be effective throughout the length of the building.

[edit on 5/16/2008 by Griff]

Originally posted by PplVSNWO
Ok, how about the information that it could withstand a fully loaded 707 at 600 mph? Surely they didn't mean the tower was designed withstand a plane impact at the first floor and not the upper floors?

Ok? that's all you've got to say about your source taking quotes out of context? Nice.

Here's the deal about the 707:

The towers were never specifically designed to take a plane hit. When they were proposed, a group was campaigning against them, and used the Empire State Building incident - a B-25 lost in the fog, low on gas, and trying to land - as just one of their objections. So Robertson did a back of the envelope calculation that the towers would survive a similar event with a 707. This of course didn't appease the group against their being built, and there was a lot of bad press. So to calm everyone down, a Port Authority architect made the statement that Robertson's calculations said they could take a hit from a fully loaded 707, at 600 mph, rather than the trying to land scenario. He lied, and nobody ever bothered to correct the architect's statement. After 9/11 Robertson says that the architect's statement is bs, but of course this doesn't stop truthers from AGAIN using an architect's staement out of context to prove an inside job.

scott-juris.blogspot.com...

reply to post by Seymour Butz


Regardless of whether or not the towers were specifically designed to take a hit from a 707 matters not. Griff showed that NIST own figures show a FOS that would have been more than sufficient to hold up to the impacts and fires. Do you have evidence to refute the NIST report or Griff's calculations based on their data?

What about this, taken out of context also?

The buildings have been investigated and found to be safe in an assumed collision with a large jet airliner (Boeing 707—DC 8) traveling at 600 miles per hour. Analysis indicates that such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact.

City in the Sky, Times Books, Henry Hold and Company, LLC, 2003,

Again, why does it matter if the towers were designed to take the impacts or if calculations showed that they could?


[edit on 16-5-2008 by PplVSNWO]

Originally posted by PplVSNWO

Regardless of whether or not the towers were specifically designed to take a hit from a 707 matters not. Griff showed that NIST own figures show a FOS that would have been more than sufficient to hold up to the impacts and fires. Do you have evidence to refute the NIST report or Griff's calculations based on their data?

No, Griff's calcs look reasomable, so why would I argue against it? The 20x as strong has been proven to be a lie, based on an out-of-context quote. My whole point here on this subject is that CTers repeat lies that they're told or that they've seen on youtube without actually looking at a dissenting view.

The same goes for the 707 thing. And what matters is whether or not CTers are honest enough to stop repeating lies when they're given correct info.

Griff has given correct info regarding the FOS. I have given correct info regarding the 707.

Of course the real point is whether or not CTers will begin to question their whole view of 9/11 when they are given correct info. What matters is if they will begin to question their beliefs about 9/11, given the fact that if we break down their arguments one by one, we can see that they have been lied to about the facts. How many times must these lies be exposed before the CTer begins to wonder whether or not their whole system of beliefs have been discredited enough to realize that they must make another examination of their beliefs about 9/11?

Once these beliefs have been corrected, there may still be questions. For example, Griff brings up the point of whether or not a FOS of 4 is good enough to prevent collapse. At least now we can proceed from a place of honesty. Agree?

Originally posted by bsbray11

Show me where anyone made the argument you just claimed, the way you just claimed it. You don't need a FoS of 20.

You do it all the time. You don't believe that the towers should have collapsed. You have used the 20x out-of-context quote to make your point.

Now that you have the right info - FOS = 4 - you're just hand waving away the lies that you've believed all this time as inconsequential to that belief.

www.abovetopsecret.com...

That's a safety factor of 20. That's 20x redundant.
Compare those numbers to the 2000% (FoS of 20) John Skilling's firm was quoted at putting certain perimeter columns. Again, I wonder which those were? (Hint: if it were the bottom-most columns, that would be a pretty ridiculous ultimate strength that they were be rated for, huh? 20x the weight of the entire building above them? I don't think so.)

reply to post by Seymour Butz


So, given the FOS that Griff's numbers show and you agreed to, do you still agree with NIST's findings and insist the planes brought down the buildings?

Originally posted by PplVSNWO

So, given the FOS that Griff's numbers show and you agreed to, do you still agree with NIST's findings and insist the planes brought down the buildings?

I can see I've wasted my time here.

NIST doesn't say that the planes brought down the buildings.

Ignorance of what NIST says is acceptable, to a certain point. Ignorance is not necessarily bad thing. I am ignorant of things related to 9/11. But I am also intelligent enough to know what those boundaries are.

I can't see where this can apply to you however.

Good luck with your investigoogling.

I am sorry I didn't spell it out further, you believe the plane crash and resulting office fires weakened columns enough to result in collapse initiation but your computer model couldn't show the global collapse?

Assuming they were right and 15% of the columns were severed, with few steel showing it had reached 600 degrees, with an estimated SOF of 4, where does that put us now?