Leslie Robertson and the 707

A common claim made about the WTC is the they "were designed to withstand multiple hits from a jet plane." or some other variation on this theme.

That is not exactly true. Let's see what the engineer himsef has to say about this.

NARRATOR: Before signing off on the design, Robertson and his team performed one last unprecedented safety check.

Leslie Robertson: One of my jobs was to look at all of the possible events that might take place in a highrise building. And of course there had been in New York two incidences of aircraft impact, the most famous one of course being on the Empire State Building. Now, we were looking at an aircraft not unlike the Mitchell bomber that ran into the Empire State Building. We were looking at aircraft that was lost in the fog, trying to land. It was a low-flying, slow-flying 707, which was the largest aircraft of its time. And so we made calculations, not anywhere near the level of sophistication that we could today. But inside of our ability, we made calculations of what happened when the airplane goes in and it takes out a huge section of the outside wall of the building. And we concluded that it would stand. It would suffer but it would stand. And the outside wall would have a big hole in it, and the building would be in place. What we didn't look at is what happens to all that fuel. And perhaps we could be faulted for that, for not doing so. But for whatever reason we didn't look at that question of what would happen to the fuel.

source

So it is clear that that calculation was done at the end of the design phase long after the structural design was worked out. The ability of the building to withstand an airplane impact was not really a consideration in the initial design, but rather an unintentional benifit of the particular design used.

It is also clear that that calculation was based soley on the mechanical damage to the structure. Fire related damage was never considered.

I notice that there was nothing in that video that supported the "concrete core" theory.
thanks for finding this gem.

Very interesting find, thanks for posting it.

That is a little bit arrogant, coming from the engineer don't you think, talking about calculating the impact, but not the fuel, that plays a MAJOR role, as we so tragically found out.

Nice find Howard. Kind of quietens the people who claim the towers would take 'multiple' collisions.

The construction manager said that in his opinion the towers would be strong enough to take several impacts of 707s. He thought that the buildings were the strongest every built and that even multiple impacts wouldn't bring them down. That's where that claim comes from.

We were looking at aircraft that was lost in the fog, trying to land.

Not an airplane that was cruising at a smooth 500mph aiming straight at the towers filled with a full tank of fuel.

I am very open-minded on 9/11, I can understand the force of the impact was deffinately enough to cripple the building. This alone does not conclude anything in my mind, but it does leave me tangled in this web.

Ed: 600mph for the second tower.

[edit on 23-5-2006 by chissler]

Originally posted by CaptainLazy
Nice find Howard. Kind of quietens the people who claim the towers would take 'multiple' collisions.

Not really. What Howard is trying to say is that the fires were the unaccounted-for variable.

What he didn't tell you is that there still isn't any evidence that the fires were hot enough to initiate collapses. The fires would've had to have done a lot more structural damage than the impacts did to bring down even one floor, and yet we see at most only a handful of bent columns that could appear bent for any number of reasons. The impacts knocked more columns completely out than NIST or anyone else has shown only "buckled" pre-collapse.

Originally posted by CaptainLazy
Kind of quietens the people who claim the towers would take 'multiple' collisions.

Don't mistake lack of debate for acquiescence. I see bsbray has already stated what I was thinking.

Consider, though, that we're just tired of arguing about it. There comes a time when I say, "Believe whatever you want."

There is very little in the way of information that anyone could bring forth that would change my mind about the towers. I'm usually pretty open-minded about various theories, but I guess you could say that I'm pretty much 'married' to this one.

Originally posted by Zaphod58
The construction manager said that in his opinion the towers would be strong enough to take several impacts of 707s. He thought that the buildings were the strongest every built and that even multiple impacts wouldn't bring them down. That's where that claim comes from.

The construction manager in 2001. He was 14 when the towers were built.

Originally posted by Benevolent Heretic

Originally posted by CaptainLazy
Kind of quietens the people who claim the towers would take 'multiple' collisions.

Don't mistake lack of debate for acquiescence. I see bsbray has already stated what I was thinking.

I apologise, I meant to say 'should' quieten. But we all get things wrong at some point

I guess this just adds more substance into the debate rather than ends it.

Originally posted by chissler

We were looking at aircraft that was lost in the fog, trying to land.

Not an airplane that was cruising at a smooth 500mph aiming straight at the towers filled with a full tank of fuel.

I am very open-minded on 9/11, I can understand the force of the impact was deffinately enough to cripple the building. This alone does not conclude anything in my mind, but it does leave me tangled in this web.

Ed: 600mph for the second tower.

[edit on 23-5-2006 by chissler]

As stated in many reports the aircraft were only half full of fuel and at least half of that would have been burned up in the intial explosion. The jet fuel that was left would have also burned up very quickly.

[edit on 24-5-2006 by ULTIMA1]

I don't think that it burned up all that quickly. Liquid jet fuel has to vaporize before it can burn. Fuel that soaked into carpet and furnishings would have taken a while to burn.

In any case, the combustion of that fuel would have released a tremendous amount of heat into the buiding.

I can understand the force of the impact was deffinately enough to cripple the building.

Have you even read the official reports? They state themselves that something like 10 - 15 % of the exterior and core columns were severed.

Mod Edit: BB Code.

[edit on 25/5/2006 by Mirthful Me]

Even if it was the plane and fire that bought the towers down they would not have collapse in the way they did imo...

We would have had a partial collapse where the lower floors at least from halfway down would have remained standing.

In fact if you look at building 2 it did exactly what you would expect, the top started to topple at the point of impact. For this to happen the lower floors must have been able to hold the weight.

The weird thing is this normal process suddenly changed it's mind, and the sideways inertia suddenly became a vertical collapse. Once the topple initiated a lot of the weight was not on the lower floors anymore, it was on one side, the pivot point. So what caused the neat downward collapse?
Physics would dictate the top would continue it's inertia and fall over maybe damaging some of that building on the pivot side.

Howward is only giving you half the story, and of course you are all jumping at it because it fits what you want to believe, not what physics proves!

BTW anyone else notice most all of the posterss jumping in here with one liners to support Howward are new posters? Hmmmm been a lot of that lately it seems.
They must be getting desperate to stop these 'silly conspiricy theories?? Hmmmm

[edit on 25/5/2006 by ANOK]

Originally posted by HowardRoark
I don't think that it burned up all that quickly.

All of it probably never burned up. But the vast majority of it did.

Even the government admits that much. That's why NIST turned to setting office materials afire for their tests.

You used to be on top of all that office fire stuff. Did the disinfo agenda change, Howard? Emphasizing different spins of the same information that's been around for years?