structural engineer leslie robertson interview

reply to post by Griff


Other things explode besides C-4, Bermdex, Comp-B, etc.

It is still not accurate to conclude it is explosives and not something else.

What would be the structural impact of explosives at those points?
How would they impact the fall of the building (since they appear to be on the same side)?

Even saying they are linear steel cutting charges what impact would they have?
Since we cannot visibly see what is going on in the building we would need to see how the floors were laid out where those dust jets are (up to date with office space etc) to see if there was anything else that could have caused them.
If there is nothing then you can start looking for explosives.





[edit on 24-3-2009 by Achorwrath]

Originally posted by thedman
One thing to consider is the solid oxygen generators on the aircraft - use
burning reaction between iron powder/potassium perchlorate to
generate O2 for emergency breathing.

I'm interested in this. How much is on board? Could it cause a thermitic reaction? Could that be the mysterious glowing molten metal pouring from the impact floors?

So many questions.

Originally posted by Achorwrath
not to mention that many aircraft fires can reach 3000F due to fuel and accelerants.

It still doesn't answer the burning question of what happened to WTC 7. Pun really not intended.

Originally posted by Achorwrath
reply to post by Griff

 

Other things explode besides C-4, Bermdex, Comp-B, etc.

It is still not accurate to conclude it is explosives and not something else.

The point was that when we talk about the lobby "explosions", we are told..."no, no, no...they were "deflagrations" because jet feul can't explode like that". But, then when we show tremendous damage to the lobby and parking garage, it suddenly becomes "explosions" again?

Go back a few pages and re-read Cameron's posts about "deflagration" vs. "explosion". So, I ask Cameron: If the jet fuel can't "explode", what caused those "explosions"?

What would be the structural impact of explosives at those points?
How would they impact the fall of the building (since they appear to be on the same side)?

Even saying they are linear steel cutting charges what impact would they have?

Don't you remember Bush's speech about Sheik Shammallama-ding-dong "the master-mind of 9/11" where Bush says about "placing the explosives on the bottom levels to trap more people"? Possibility? If so, why was it ignored?

Since we cannot visibly see what is going on in the building we would need to see how the floors were laid out where those dust jets are (up to date with office space etc) to see if there was anything else that could have caused them.
If there is nothing then you can start looking for explosives.

Too bad the real structural documentation is hidden from us, eh?

[edit on 3/24/2009 by Griff]

reply to post by Griff


I think one of the big problems is that we all are replying to many people at once, terms get thrown around items added into posts (that is why some of mine seem to jump around).

the deflafration comment was about damage in the lobby and on lower floors.

Bonez showed the images of the dust jets saying they were proof of explosives. I commented that saying they were explosives was speculation.

I agree, I would like more information. I once read there was a "gag' order put in place by the designers of the WTC towers and WTC7 but I cannot find anything real on that so it remains as rumor and not confirmed.

reply to post by Griff


There is a difference between deflagration and detonation.

Your playing the silly semantics game again my friend. (along with a little Cherry picking)

You know that if you are close enough to the detonation of a bomb to get your skin burned off, your body will be ripped apart.



My post was in response to Bonez regarding his claim that jet fuel was only at the impact points. I think you can agree that he is mistaken.



[edit on 24-3-2009 by CameronFox]

Something interesting for us all to read.

I have made note of some things in the first report.

I wont comment here as I do not want to sway anyone in any directionlink

Very interesting reading on the condition of the towers in October 2000

Originally posted by thedman
How did fuel get dispersed ?- when the fuel tanks ruptured at 500 mph the liquid fuel was broken into droplets by air resistence and by contact with solid materials. Ever spray water from hose ? Notice how the liquid is broken up into droplets and then to mists. The fuel from American 11 fell down the elevator shafts from the 93-96 floors, a thousand foot drop The resulting mist cloud when ignited creates a violent explosion

Notice the fireball from the aircraft impact ? This is the violent burning of the aerosol cloud of jet fuel

I have a couple of problems with this scenario, which I would like to put forward…

You’re saying that the impact of the plane caused the fuel to essentially aerosolise (I say essentially, because it’s not aerosolised in the proper sense, but enough to be combustible, as seen by the fireballs). While some of this aerosolised fuel was consumed in the initial fireballs, some ‘fell’ down the elevator shafts to cause a violent explosion when ignited near the ground level.

1. The first problem I have is with the change in volume. Depending on the liquid, the physical space it takes up as an aerosol can be several hundred times that which it does in liquid form (obviously as it is now reduced to tiny particles dispersed in the air). Therefore, the hundreds of cubic feet of jet fuel (I believe NIST claim 900 cubic feet), when aerosolised, now takes up thousands of cubic feet. Now thousands of cubic feet of aerosolised jet fuel has to escape down elevator shafts measuring only a few feet square BEFORE being ignited by the initial fireball. As the numerous videos show, this would be fractions of a second.

What makes this even more unlikely is that the elevator shaft (with all of the lift doors on the floors below closed) is essentially a sealed space, meaning this cloud of thousands of cubic feet of aerosolised jet fuel has to displace the air inside the shaft which, whilst certainly not impossible, slows it down. This makes it even more unlikely not to be consumed by the initial fireball.

2. The second problem I have is that this ‘cloud’ of aerosolised jet fuel (or even liquid jet fuel, if it hasn’t aerosolised yet) can only fall down the elevator shaft at its freefall terminal velocity, yet it somehow still manages to ‘outrun’ the exploding fireball of the plane above it, in order to not have combusted before it reaches the lobby area. As the fireball is a fuelled and propelled source of energy, it easily outpaces anything travelling in freefall.

3. The third problem I have is with something called the ‘wall-attachment effect’, or Coanda effect.

From the Columbia Encyclopaedia:

Coanda effect or wall-attachment effect [is] the tendency of a moving fluid, either liquid or gas, to attach itself to a surface and flow along it. As a fluid moves across a surface a certain amount of friction (called “skin friction”) occurs between the fluid and the surface, which tends to slow the moving fluid. This resistance to the flow of the fluid pulls the fluid towards the surface, causing it stick to the surface.

And from Wikipedia:

The Coandă effect is the tendency of a fast-moving stream of air to deflect towards nearby surfaces. The fast-moving stream tends to experience a decrease in static pressure, which creates a pressure difference between those areas far from the wall and the wall itself. This bends the fast-moving stream towards the surface and tends to keep it attached to that surface.

The scenario you pose above requires this ‘cloud’ of aerosolised jet fuel to travel over a quarter of a mile down the elevator shaft, whilst still remaining aerosolised enough to be combustible by the time it reaches the lobby area. In reality this would not happen. The wall-attachment effect means that the aerosolised jet fuel would be attracted to the walls of the elevator shaft, where the friction slows it, and it condenses back into a liquid state. By the time this ‘cloud’ would reach the lobby, it would be in the form of liquid jet fuel streaming down the walls of the elevator shaft, not in the aerosolised form required for it to be combustible.

4. And the fourth problem I have is what caused the ignition in the lobby. Even if this ‘cloud’ of aerosolised jet fuel made it all the way to the lobby, without being ignited by the initial fireball, and without having liquefied on the shaft walls, what was it that caused it to explode at the lobby level? Had someone in the lobby seen the devastation caused a quarter of a mile up and decided to have a quick smoke?

Food for thought… (nom, nom, nom…)

Rewey

And another...

5. The fifth problem I have is that this 'cloud' of jet fuel mist has to travel down the elevator shaft unimpeded... but there's ELEVATORS in the elevator shaft in the way. When this 'cloud' falls on the elevator, it would act much like rain - return to liquid form and gain in volume, then spill over the edges in liquid state.

Time and time again we read that jet fuel is not explosive in liquid form, only when 'aerosolised'. I don't think that the jet fuel in liquid state when it reached the lower areas would have the explosive capacity required to do the damage attributed to it...

Rewey

There were several engineering teams that worked on the WTC project, and their work was divided amongst them, even as far as the civil/structural engineering went.

It was John Skilling's firm that particularly investigated the towers' ability to withstand jetliner impacts, and here is what they published in the late 1960's:

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.

www.historycommons.org...

Lesilie Robertson is either a fool or a blind fool fool since he either designed the towers which ultimately failed or he is a blind fool for not recognising the towers were blown up, which is what he makes his experience out to be.

Failing that he is an lying SOB with a baby face who can tell a good story!

I find it odd and in some ways suspicious that the Japs gave him the job of designing a new skyscraper and on reflection from what I have seen I personally find his persona slightly disturbing on the whole. I think Leslie knows something but he also comes across as scared, like he's scared to say the wrong thing perhaps. He almost seems like he's playing innocent don't you think?