Do we agree the towers were designed to withstand jetliner crash?

[000063]

Please explain how Skilling's statements are important for what happened on 911. (Or if they are not, in which context they are important)

It would seem obvious that when examining truth claims for any event that the preexisting understandings of the event occurring are important, and in particular when it is expert opinion guided by scientific understandings

Experts are sometimes wrong, especially when it comes to the gap between theory and practice. For all this thread's blather, the planes that hit the Towers hadn't even rolled off the line yet. They literally did not exist. There is no way the towers could've been built to withstand them specifically, and you're having a great deal of trouble understanding the physics behind the impact, from what I've seen on the last two pages.

EDIT: Moreover, it doesn't go one whit toward proving controlled demolition, which I suspect is what you're trying to end-run here.

 

[LSSBB]

One more LSSB- So I assume your disregard for Skillings statement comes from your analysis of later facts, kind of a retrograde interpretation of relevance.

I haven't even read his statement, and by disregard, you need to specify a context. Yes, it is a retrograde interpretation of relevance. What is the problem with that? How could any interpretation of relevance be anything but retrograde, after the fact?

 

[Redwood]

I believe... the towers had to be built out of especially strong concrete and steel just to be the size they were. If the same planes had crashed into smaller, and most likely weaker buildings, they wouldn't have collapsed so much as toppled over.

The towers were large and strong enough to absorb the initial impact, and were only taken out later when fires weakened the remaining supports. If they had hit, say, the CN Tower, it probably would have been chopped in half.

The Twin Towers had no structural concrete, only steel. IIRC, the upper parts of the perimeter box columns were of a steel of higher than standard strength which enabled the use of lighter columns to reduce the load on the lower structure. IIRC, the upper columns had 1/4"(6.35mm) webs.

I am not a structural engineer, but as a scientifically educated layman, I'm impressed that the Twin Towers could absorb the impacts of jetliners traveling at about 500 mph, and not fall immediately.

 

[Redwood]

So it remains unclear how many here believe the Skilling quote was a lie. Was all of it a lie or just the part about 600 MPH? The story also says that there were separate studies. Is this a lie? What facts do you have to confirm the details of the other study?

Non Believer

http://community.seattletimes.nwsour...7&slug=1687698

http://www.historycommons.org/entity...ohn_skilling_1

Not relevant to study of the collapses anyway, but John Skilling is never quoted in either of your sources as stating the building was designed to withstand the impact of a jetliner traveling at 600 mph. The History Commons article refers to a 3-page "White Paper", written before the Port Authority had even begun to exercise eminent domain over the future WTC site, but the author are unknown, it is not an engineering paper, and the article continues, "However, besides this paper, no documents are known detailing how this analysis was made."

The most charitable interpretation I can give to this is that your reading comprehension skills are very poor.

As there is no evidence that the Twin Towers collapsed from anything other than high speed impact and fire, any 1964 engineering paper which might ever turn up, which declared they would survive, would be mostly of historical interest to see where they went wrong.

 

[Justin39640]

Frankly, I am at a complete loss to even imagine which facts and expertise led you to this opinion

My opinion and fixing things that slammed together and broke apart for the last 2 decades.

Well, let's suppose a 767 doing the same speed hit a building with half the cross section as the towers. That would mean a larger percentage of support would be damaged, hastening the onset of complete failure. How long did the pentagon stand before that section of the E ring collapsed? 30 minutes? It only had 4 stories above the damaged region and it was designed for a full frontal attack. A much different animal than most buildings in the world.

As far as the ESB, it wasn't hit by a 767 or anything like it doing anywhere near the same speed. Hit the ESB the way the towers were hit and I think it would have been a much different scenario.

The towers were GIANT. If you never stood at their bases I don't think you could imagine it. Even in a city of giants, they were monsters.

Again, this is just my opinion. No expertise, though, I could have sworn I read somewhere that most buildings wouldn't have survived the impacts. I would love for someone with expertise to explain why I'm wrong. Unlike truthers, I'll absorb it and change my opinion.

 

[Oystein]

http://community.seattletimes.nwsource.com/archive/?date=19930227&slug=1687698


http://www.historycommons.org/entity.jsp?entity=john_skilling_1

It has long since been acknowledged that calculations done in 1964, and later, showed that the towers could absorb airplane crashes and neither topple over at the base from shear nor collapse at the impact zone from having perimeter columns cut out.

In the reality of 9/11/2001, these calculations proved true: Neither the lateral shear force nor the cutting of columns made the towers collapse.


What you now need to acknowledge is:

1. The deisgn of the towers was completed in january 1964, so those calculations were done after the design phase, and hence plane crashed were not part of the design objectives
2. The effect of additional unfought fires was not considered, and could not have been considered, given the lack of computer power back then and the enormous complexity of modelling such an event.

You link to a newspaper article in which statements from an interview with Skilling, done 29 years after he worked on those designs, are reproduced. The Skilling quote does not imply that the effects of those horrendous fire in the minutes and hours after a plane crash were calculated in the 1964 assessment. Skilling simply does not talk about those effects. He only talks about effects on people in the building (who would get killed by horrendous fires). So when Skilling says "The building structure would still be there", he is very probably speculating, perhaps forgetting about the other effects of fire, and at any rate simply mistaken.

Also, consider if Skilling could be expected to have stated in 1993 that his "babies" were vulnerable to total collapse! Would he say that if a reporter asked him? He would have two excellent reasons to lie: a) to cover his own arse b) to not give future terrorists a hint on how to destroy the towers

 

[Oystein]

At a minimum it would indicate the science being used at the time was faulty to a degree that thousands perished because of it.

No science was even possible in and before 1964 to calculate all of the effects of a fully fueled 707 crashing at high speed into anything, as this would require massive computer power that did not exist at the time.

Please acknowledge this simple and obvious fact!


All that was possible at the time was simple, static modelling:
How much lateral force would a crashing plane excert on the towers? Is that more or less than the maximum designed-for lateral shear force (which was actually the maximum designed-for wind load)? And could gravity loads be redistributed without global failure if you cut out n columns along the wingspan of a 707?
Those calculations were indeed done, and it was found that the towers would neither pivot over their bases and topplke over, not immediately collapse at the impact area.
And that 1964 science proved correct in 2001.

Please acknowledge that you understand that the science that was possible in 1964 proved to be correct!

Seemingly an overhaul of architectural expertise would be in order, but none seems forthcoming

This is FALSE. An overhaul of architectural expertise has been done, and is always in progress.

The NIST reports on the twin tower collapses make recommendations that address and update the existing expertise. They looked at various areas where improvements are possible, such as making passive fire protection, active fire protection and inhabitant egress options more resilient to such catastrophic events.

Also, as a matter of fact, with available computer power ever increasing, precisely the things that were impossible in 1964 are now more and more routinely employed in innovative structural designs, namely dynamic response to wide ranged of conditions.

 

[Cl1mh4224rd]

All science is theory.

Where does "observation" fit in?

 

[Oystein]

...But a minimum there was a separate study done by Skilling which included a fire analysis ...

No.

You have not shown evidence of this.

Was it at all possible in 1964 to model such a plane crash, including distribution of fuel, development of fire, heating of building materials and structural response - yes or no?

 

[Oystein]

My opinion and fixing things that slammed together and broke apart for the last 2 decades.

Well, let's suppose a 767 doing the same speed hit a building with half the cross section as the towers. That would mean a larger percentage of support would be damaged, hastening the onset of complete failure. How long did the pentagon stand before that section of the E ring collapsed? 30 minutes? It only had 4 stories above the damaged region and it was designed for a full frontal attack. A much different animal than most buildings in the world.

As far as the ESB, it wasn't hit by a 767 or anything like it doing anywhere near the same speed. Hit the ESB the way the towers were hit and I think it would have been a much different scenario.

The towers were GIANT. If you never stood at their bases I don't think you could imagine it. Even in a city of giants, they were monsters.

Again, this is just my opinion. No expertise, though, I could have sworn I read somewhere that most buildings wouldn't have survived the impacts. I would love for someone with expertise to explain why I'm wrong. Unlike truthers, I'll absorb it and change my opinion.

Well ok, sure, a significantly smaller and more slender building could not absorb the same energy at the same wingspan without losing a far greater proportion of its capacity. I was thinking about highrises of the same order of magnitude but different design. The ESB for example is heavier, with a conventional steel frame, but with variable width. It might very much depend on where and how a plane crashed into it; I'd expect a partial collapse in most scenarios, no collapse in some, and total collapse in a few at most. What about the Taipei 101? It has two super-columns, 3x2.6 meters steel boxes filled with high-strength concrete, in each of the four corners; these have connections to the core only once every 8 floors. It is designed to withstand strong earthquakes and super-typhoons. I think it would easily survive a 9/11-like attack in most scenarios. But has a few peculiar vulnerabilities. If you manage to knock loose the 660 ton steel pendulum near the 90th floor, you'll probably wreck quite a bit...
The Willis Tower in Chicago (formerly Sears Tower) is wider than the WTC twins on all sides up to the 50th floor; above that, effective width would depend on where and at what angle a plane would strike. How would it perform? I couldn't guess.

 

[triforcharity]

I sent a question to history commons trying to clarify this. But a minimum there was a separate study done by Skilling which included a fire analysis which Robertson has never mentioned

A fire analysis done in the 1960's would be horribly inaccurate. Not only was fire science in it's infancy, but much of what was known about fire and it's behaviors was minimal, but much was wrong. Not due to incompetence, but due to the fact that the way fire was studied then was crude, and most calculations were done with pencil and paper. Not with the complex algorithms and incredibly vast knowledge of fire that we have now.

Conclusion: any study on fire done in the 1960's is useless.

 

[MRC_Hans]

Well maybe Hans can clarify what he meant.

What Skilling said was 'theory' as in 'opposite to practice'.

The point is not only what Skilling said, but what degree his statements represented the scientific understandings of the time

Why is this important? If the 911 events had happened shortly after, the experience might have improved the predictive powers of calulation methods of the time, but now we have far more advanced methods.

We still don't know if Skilling's prediction was precise, since the event he based it on did not happen.

Honestly, what are we really discussing here? - And why?

Hans

 

[jaydeehess]

We still don't know if Skilling's prediction was precise, since the event he based it on did not happen.

Honestly, what are we really discussing here? - And why?

Hans

The severe out of context audacity by the 9/11 truth movement, when they claim that a slow and low on fuel 707, or a tiny B-25, is at all comparable to a fast and fuel laden 756/767, is utterly astounding in its dishonesty, or in its shining display of utter ignorance.

To claim that the towers were specifically designed to withstand impacts is ridiculous when history shows that any calculations to that effect were done as an aside to the design project, after design had been finalized, and that no alterations to design were ever made due to these calculations.

At least that's my humble opinion.

 

[MRC_Hans]

One more LSSB- So I assume your disregard for Skillings statement comes from your analysis of later facts, kind of a retrograde interpretation of relevance.

What would be wrong with that? There once was an otherwise well reputed scientist (I forget who) who about a century ago determinedly declared that meorites could not come form space. For his contemoraries, that was an authoritative and important statement, but viewed today, in retrograde, it was, of course, complete nonsense.

Reality sometimes does that to the best authorities.

Hans

 

[MRC_Hans]

The severe out of context audacity by the 9/11 truth movement, when they claim that a slow and low on fuel 707, or a tiny B-25, is at all comparable to a fast and fuel laden 756/767, is utterly astounding in its dishonesty, or in its shining display of utter ignorance.

To claim that the towers were specifically designed to withstand impacts is ridiculous when history shows that any calculations to that effect were done as an aside to the design project, after design had been finalized, and that no alterations to design were ever made due to these calculations.

At least that's my humble opinion.

Humble as it may be, that opinion appears to be solidly backed by fact.

Hans

 

[jaydeehess]

What would be wrong with that? There once was an otherwise well reputed scientist (I forget who) who about a century ago determinedly declared that meorites could not come form space. For his contemoraries, that was an authoritative and important statement, but viewed today, in retrograde, it was, of course, complete nonsense.

Reality sometimes does that to the best authorities.

Hans

Equally knowledgable statements pronounced that rockets could not work in the vaccum of space due to there being nothing to push against and earlier than that, that passengers in wagons pulled by a proposed, new invention, the railroad engine, would asphyxiate due to lack of air when moving upwards of 30 mph.

 

[jaydeehess]

Humble as it may be, that opinion appears to be solidly backed by fact.

Hans

thank you, I believe so as well.

 

[davefoc]

What would be wrong with that? There once was an otherwise well reputed scientist (I forget who) who about a century ago determinedly declared that meteorites could not come form space. For his contemporaries, that was an authoritative and important statement, but viewed today, in retrograde, it was, of course, complete nonsense.

Reality sometimes does that to the best authorities.

Hans

Wikiquote has a little collection of this kind of thing:
http://en.wikiquote.org/wiki/Incorrect_predictions

A few samples:
Heavier-than-air flying machines are impossible. - Lord Kelvin
While theoretically and technically television may be feasible, commercially and financially it is an impossibility, a development of which we need waste little time dreaming. - Lee de Forest
Television won't last because people will soon get tired of staring at a plywood box every night. - Darryl Zanuck

It does seem there is evidence that experts are wrong sometimes, but is this even relevant to this discussion? I haven't seen where any particular expert was shown to be wrong. That is, unless one is talking about the truther experts and is there such a thing? If one advocates for one of the craziest, most wildly impossible theories of all time can one said to be an expert at it?

 

[1337m4n]

Do we agree that the Titanic was designed to withstand minor collisions? That it was once called "unsinkable"?

Even the smartest engineer can't foresee *every* possibility. The WTC designers foresaw plane crashes, and they foresaw raging fires...but they did not foresee both *combined*.

"Best laid plains o' mice and men", you see.

 

[MRC_Hans]

Do we agree that the Titanic was designed to withstand minor collisions? That it was once called "unsinkable"?

Even the smartest engineer can't foresee *every* possibility. The WTC designers foresaw plane crashes, and they foresaw raging fires...but they did not foresee both *combined*.

"Best laid plains o' mice and men", you see.

Actually, she was designed to withstand a major collision. Had they sailed directly into that iceberg, at full speed, there would no doubt have been some casualties onboard as half a dozen yards of the bow was turned into scrap iron and everything was thrown around, but she would not only have remained floating, but would probably have been able to reach harbour under her own power.

As it were, the grazing blow opened up a long row of individually insignificant leaks, flooding two many watertight compartments.

Again, reality foiled theory.

Hans