Charlie Thornton discussing a plane possibly hitting the WTC

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This brings up an excellent question. If you guys are so fixated on the education and experience of anyone who dares comment about 9/11 collapses in a contrary fashion to your beliefs, then please tell us who the engineers were that carried out the 1964 plane impact study, and what their education level and experience was.

Remember, by Tony's own standards, 12 years experience is not enough. So we presume those engineers must have had much more experience, otherwise their conclusions should be similarly dismissed.
So now we look forward to the presentation of their qualifications by Tony and Gerry. (Well, we know that isn't going to happen, but I think I've made my point regarding the double-standard)
 
This brings up an excellent question. If you guys are so fixated on the education and experience of anyone who dares comment about 9/11 collapses in a contrary fashion to your beliefs, then please tell us who the engineers were that carried out the 1964 plane impact study, and what their education level and experience was.

Remember, by Tony's own standards, 12 years experience is not enough. So we presume those engineers must have had much more experience, otherwise their conclusions should be similarly dismissed.
So now we look forward to the presentation of their qualifications by Tony and Gerry. (Well, we know that isn't going to happen, but I think I've made my point regarding the double-standard)
Worthington, Skilling, Helle & Jackson see post #30 in this thread.
 
This brings up an excellent question. If you guys are so fixated on the education and experience of anyone who dares comment about 9/11 collapses in a contrary fashion to your beliefs, then please tell us who the engineers were that carried out the 1964 plane impact study, and what their education level and experience was.

Remember, by Tony's own standards, 12 years experience is not enough. So we presume those engineers must have had much more experience, otherwise their conclusions should be similarly dismissed.
So now we look forward to the presentation of their qualifications by Tony and Gerry. (Well, we know that isn't going to happen, but I think I've made my point regarding the double-standard)

I don't have any qualifications to do forensic analysis. I am licensed as an architect in NYS and worked as one since 1970. I do not design steel framed buildings although I have worked on them. We use a consulting engineer for our projects.
 
Tony, this isn't even valid as argumentation by the forum guidelines. You're not addressing any particular point I made.

I'm as qualified as you are to read the white paper, note Robertson and Skilling's comments and the fact that Robertson was a professional engineer for 12 years before the 1964 study was done.
Worse, you don't even know who performed the study. Or do you know which engineers did it? Please tell us!

Let's get it straight that you asked me whether or not I felt qualified to comment before I made any point along those lines. In reply I said what I did about your qualifications to comment because I see you speciously attributing experience to Leslie Robertson, at a certain point in his career, and I don't think you have a basis to judge from.

The bottom line here is that there appears to be a conflict between what John Skilling and Leslie Robertson have said about the aircraft impact study and building survivability.

During the design of the WTC Towers John Skilling was a senior engineer and a full partner in the engineering firm. Leslie Robertson was not at that point. I am sure John would have had much more overall responsibility for the job than Leslie did at the time. John said, in a very emphatic and direct way, that the analysis showed the biggest problem would be all of the fuel dumping into the building and that there would be a horrendous fire with a lot of people killed but the damage would only be local and the building would still be there. Leslie's comments along those lines were that he didn't think they considered the fuel. The difference in certainty makes me think that Leslie had little to do with the analysis and wasn't quite sure of what it said, while John was directly responsible and knew precisely what it said.
 
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Let's get it straight that you asked me whether or not I felt qualified to comment before I made any point along those lines. In reply I said what I did about your qualifications to comment because I see you speciously attributing experience to Leslie Robertson, at a certain point in his career, and I don't think you have a basis to judge from.

The bottom line here is that there appears to be a conflict between what John Skilling and Leslie Robertson have said about the aircraft impact study and building survivability.

During the design of the WTC Towers John Skilling was a senior engineer and a full partner in the engineering firm. Leslie Robertson was not at that point. I am sure John would have had much more overall responsibility for the job than Leslie did at the time. John said, in a very emphatic and direct way, that the analysis showed the biggest problem would be all of the fuel dumping into the building and that there would be a horrendous fire with a lot of people killed but the damage would only be local and the building would still be there. Leslie's comments along those lines were that he didn't think they considered the fuel. The difference in certainty makes me think that Leslie had little to do with the analysis and wasn't quite sure of what it said, while John was directly responsible and knew precisely what it said.
Tony, I accept the idea that the fuel analysis, to whatever extent was possible in 1964 (unknown to me, but as Mick suggests they didn't have the computers we do obviously) was done.
But what is very much a question is how a 'low flying, slow flying' aircraft along the lines of the ESB collision becomes 600mph! After all, that's supposed to be an impossible speed anyway, it seems odd that the study would look at something which wasn't possible. Even more dubious as we have no written copy of the study. It's all hearsay.
It's equally likely the study looked at a 180mph collision, and that the science of the time didn't allow for the kind of precision we might have today. Therefore on the cautious side we'd have to be very careful about accepting the idea that the towers could really withstand the assaults which they suffered.
I prefer a cautious approach, others are less exacting. If we don't know, that's fine; we don't know. But we should keep in mind the limits of our knowledge and not get carried away with speculation. IMO that does not get us closer to any truth, and it might get us further away!
 
Tony, I accept the idea that the fuel analysis, to whatever extent was possible in 1964 (unknown to me, but as Mick suggests they didn't have the computers we do obviously) was done.
But what is very much a question is how a 'low flying, slow flying' aircraft along the lines of the ESB collision becomes 600mph! After all, that's supposed to be an impossible speed anyway, it seems odd that the study would look at something which wasn't possible. Even more dubious as we have no written copy of the study. It's all hearsay.
It's equally likely the study looked at a 180mph collision, and that the science of the time didn't allow for the kind of precision we might have today. Therefore on the cautious side we'd have to be very careful about accepting the idea that the towers could really withstand the assaults which they suffered.
I prefer a cautious approach, others are less exacting. If we don't know, that's fine; we don't know. But we should keep in mind the limits of our knowledge and not get carried away with speculation. IMO that does not get us closer to any truth, and it might get us further away!

Skilling's studies were inadequate because they failed to reveal that although the structure would survive the impact... and they did... and the fires would cause additional tremendous destruction and loss of life... it did... the two together over time led to what was ROOSD which was the undoing of the entire building(s). The long span floor system was susceptible to ROOSD and that was what both Skilling and Robertson failed to explore at the time. It seems that Robertson, at least post collapse understood the towers vulnerability to ROOSD without referring to this process by any name or acronym. In the end the quick build floor system was why the whole building collapsed to the ground.
 
Skilling's studies were inadequate because they failed to reveal that although the structure would survive the impact... and they did... and the fires would cause additional tremendous destruction and loss of life... it did... the two together over time led to what was ROOSD which was the undoing of the entire building(s). The long span floor system was susceptible to ROOSD and that was what both Skilling and Robertson failed to explore at the time. It seems that Robertson, at least post collapse understood the towers vulnerability to ROOSD without referring to this process by any name or acronym. In the end the quick build floor system was why the whole building collapsed to the ground.
"Skilling's studies were inadequate" Please tell me you are joking. Otherwise, I find it hard to believe I am seeing someone, who admits he has no calculations to back up what he is saying, make this statement.
 
Tony, I accept the idea that the fuel analysis, to whatever extent was possible in 1964 (unknown to me, but as Mick suggests they didn't have the computers we do obviously) was done.
But what is very much a question is how a 'low flying, slow flying' aircraft along the lines of the ESB collision becomes 600mph! After all, that's supposed to be an impossible speed anyway, it seems odd that the study would look at something which wasn't possible. Even more dubious as we have no written copy of the study. It's all hearsay.
It's equally likely the study looked at a 180mph collision, and that the science of the time didn't allow for the kind of precision we might have today. Therefore on the cautious side we'd have to be very careful about accepting the idea that the towers could really withstand the assaults which they suffered.
I prefer a cautious approach, others are less exacting. If we don't know, that's fine; we don't know. But we should keep in mind the limits of our knowledge and not get carried away with speculation. IMO that does not get us closer to any truth, and it might get us further away!
The white paper does say that the analysis looked at a 600 mph impact and maybe they looked at several velocities, including a 180 mph one. Landing speeds are 160 mph so 180 mph would be an approximate minimum for coming in for a landing. If I were doing the study I would start off with that and step it up to see if there is a problem at any speed the jet was capable of. The aircraft could take 600 mph at sea level although it might have serious control problems and suffer some structural damage. However, that would not deter a building damage study from looking at it as an impact velocity, since it could still occur in an accidental way if the pilot lost control from above or throttles stuck or something like that.

The science of the time was capable of discerning the damage probability and severity to a reasonable degree. FEA is nothing more than F = Kx for a lot of elements. A coarser analysis could ballpark it. Enik has commented that I unknowingly validated one of his FEAs with a hand calculation.
 
"Skilling's studies were inadequate" Please tell me you are joking. Otherwise, I find it hard to believe I am seeing someone, who admits he has no calculations to back up what he is saying, make this statement.

Well... You tell me.... he got the fact that the impact would not directly cause a complete structural failure correct, but he failed to take into account the weakening from fire and the mechanical damage would lead to ROOSD.

I don't need calculations. I saw what happened.

I sail. I don't know how to design a hull, a keel or a sail or do the calculations.. but I know how to make the boat sail with the wind. Tony, your maths have been shown by others to have mistakes. So what's the point of math if they are incorrect? You make up things as well along the way.

You can fool some of the people some of the time, but you can't fool all the people all the time... or something like that.
 
The white paper does say that the analysis looked at a 600 mph impact and maybe they looked at several velocities, including a 180 mph one. Landing speeds are 160 mph so 180 mph would be an approximate minimum for coming in for a landing. If I were doing the study I would start off with that and step it up to see if there is a problem at any speed the jet was capable of. The aircraft could take 600 mph at sea level although it might have serious control problems and suffer some structural damage. However, that would not deter a building damage study from looking at it as an impact velocity, since it could still occur in an accidental way if the pilot lost control from above or throttles stuck or something like that.

The science of the time was capable of discerning the damage probability and severity to a reasonable degree. FEA is nothing more than F = Kx for a lot of elements. A coarser analysis could ballpark it. Enik has commented that I unknowingly validated one of his FEAs with a hand calculation.

Tony, please just can we agree that the white paper wasn't produced by the engineers? It was, I believe, put out by someone working for the Port Authority.
Also, can we agree that we don't have the study?
In that case we only have second hand references to it. The rest is speculation.

You still are not acknowledging that Robertson said it was looking at a 'low flying, slow flying' airplane lost in fog. Why do you avoid this statement?

The weakest part of your apparent argument that the towers would survive is that NOBODY in history had every conducted a full-scale experiment of such an event, the only time in history that a real jet has done this was on 9/11. Simple logic dictates that we need to accept this as a clear precedent, and not get carried away trying to read too much into it.
There simply is not experimental data to say that the collapses should not have happened. It's an exercise in trying to prove a negative anyway, which is impossible.

If you are trying to argue something which is impossible, you'll fail if doing so with people who recognize the nature of the argument. Perhaps you're not used to such critical demands, I don't know. But as I've outlined, the actual study is lost. If, for some strange reason engineers were to do another study using modern tools, they might find that the tower would collapse.
How would you react to that? Surely you must realize this is a real possibility!
 
Well... You tell me.... he got the fact that the impact would not directly cause a complete structural failure correct, but he failed to take into account the weakening from fire and the mechanical damage would lead to ROOSD.

I don't need calculations. I saw what happened.

I sail. I don't know how to design a hull, a keel or a sail or do the calculations.. but I know how to make the boat sail with the wind. Tony, your maths have been shown by others to have mistakes. So what's the point of math if they are incorrect? You make up things as well along the way.

You can fool some of the people some of the time, but you can't fool all the people all the time... or something like that.

The analysis John Skilling spoke of did consider fires started from the fuel and would have certainly considered any heating effects.
Yes, you do need calculations. Otherwise what you are saying is conjecture.

My math on this issue has not been shown to be incorrect and you can't just say that and have people take it as a reality. Show us where my math is mistaken.
 
Tony, please just can we agree that the white paper wasn't produced by the engineers? It was, I believe, put out by someone working for the Port Authority.
Also, can we agree that we don't have the study?
In that case we only have second hand references to it. The rest is speculation.

You still are not acknowledging that Robertson said it was looking at a 'low flying, slow flying' airplane lost in fog. Why do you avoid this statement?

The weakest part of your apparent argument that the towers would survive is that NOBODY in history had every conducted a full-scale experiment of such an event, the only time in history that a real jet has done this was on 9/11. Simple logic dictates that we need to accept this as a clear precedent, and not get carried away trying to read too much into it.
There simply is not experimental data to say that the collapses should not have happened. It's an exercise in trying to prove a negative anyway, which is impossible.

If you are trying to argue something which is impossible, you'll fail if doing so with people who recognize the nature of the argument. Perhaps you're not used to such critical demands, I don't know. But as I've outlined, the actual study is lost. If, for some strange reason engineers were to do another study using modern tools, they might find that the tower would collapse.
How would you react to that? Surely you must realize this is a real possibility!
I don't think John Skilling would have been talking about the analysis the way he did in 1993 if it were just for PR. So I cannot agree with you on that point, although I do appreciate your thinking of possibilities.
 
Have a look over at JREF or the 9/11 Free Forum...
Get real. Those people have not shown any of my math to be incorrect. Enik even told someone they were full of it when they tried to make an unsupported claim like you are here. He told them that unbeknownst to me that I had validated one of his FEAs with hand calculations, and that told him that I certainly knew what I was doing.

What is actually funny here is that you admit you can't even do the calculations, yet you want to say others have shown them to be wrong. How would you even know?
 
Get real. Those people have not shown any of my math to be incorrect. Enik even told someone they were full of it when they tried to make an unsupported claim like you are here. He told them that unbeknownst to me that I had validated one of his FEAs with hand calculations, and that told him that I certainly knew what I was doing.

What is actually funny here is that you admit you can't even do the calculations, yet you want to say others have shown them to be wrong. How would you even know?

I'm just an old dumb architect. I don't design steel frames or do forensic or structural analysis. For my work I use a consultant. I know enough to understand the BS when I see it.

nuff said

trust but verify

of... and by the way don't tell me you trust some screen name such as enik now do you?
 
I'm just an old dumb architect. I don't design steel frames or do forensic or structural analysis. For my work I use a consultant. I know enough to understand the BS when I see it.

nuff said

trust but verify

of... and by the way don't tell me you trust some screen name such as enik now do you?
I actually know enik's real name. He is a mechanical engineer with a masters degree who does structural design and analysis work like I do. We have corresponded and exchanged information over the years. I also know achimspok's real name. He is an electrical engineer and we have corresponded and exchanged information also.
 
I actually know enik's real name. He is a mechanical engineer with a masters degree who does structural design and analysis work like I do. We have corresponded and exchanged information over the years.

And other people know the posters who you ridicule for not using their real names. A totally dumb criticism to dismiss their content.
 
And other people know the posters who you ridicule for not using their real names. A totally dumb criticism to dismiss their content.
What is dumb is the contention most often put forth by those using pseudonyms that the collapses of the three buildings in NYC on Sept. 11, 2001 were naturally initiated and propagated.

One of the anonymous posters, who has been on here, and who you think is right on with his take that the collapses were natural, has actually even said he lies when he uses his real name and considers it is a chance to be honest when he uses a pseudonym. Try to understand that one.
 
What is dumb is the contention most often put forth by those using pseudonyms that the collapses of the three buildings in NYC on Sept. 11, 2001 were naturally initiated and propagated.

it wasn't naturally initiated. It was asserted that mechanical damage followed by continuous weakening and distortion of the steel frame by heat led to the collapse... and yes collapse IS natural as gravity is a natural force. The conditions the frame was subject to became out of spec ergo it failed.
 
it wasn't naturally initiated. It was asserted that mechanical damage followed by continuous weakening and distortion of the steel frame by heat led to the collapse... and yes collapse IS natural as gravity is a natural force. The conditions the frame was subject to became out of spec ergo it failed.
There was not enough gravitational energy to continue the collapse after a one or two story drop, and you can't get around the lack of deceleration without a major hand wave into a magical transition to a runaway. It doesn't happen like that. A runaway can't happen without about five stories collapsed in some other way. You also have no evidence for the heating and damage you like to think occurred to initiate things.
 
There was not enough gravitational energy to continue the collapse after a one or two story drop, and you can't get around the lack of deceleration without a major hand wave into a magical transition to a runaway. It doesn't happen like that. A runaway can't happen without about five stories collapsed in some other way. You also have no evidence for the heating and damage you like to think occurred to initiate things.

I am not a forensic investigator. I proposed mechanisms using known science about materials which ring true to me. You don't like or accept my model. Good for you. I don't care. Propose another one.
 
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