WTC7 and the girder walk-off between column 79 and 44

[LSSBB]

The temperature of the copper extrusion is highly variable. Nearly all of the heating is due to strain energy in the extrusion itself. Furthermore, the jet is at such high kinetic energy that its temperature is hard to sense -- and indeed difficult to define. Depending on the mission, one might actually attempt to tune the temperature of the copper jet, subtly altering the geometry until you got precisely the right working temperature, and thus the correct mix of strength, ductility, contact friction, abrasiveness, and secondary (heat) effect on the target.

Anyway, Sword Of Truth is of course quite correct, and Tony is of course quite full of nonsense. While it is indeed true that a shaped charge focuses its energy, and the shock wave will be strongest along that focus, it is complete madness to think there's effectively no damage away from the axis of the focus.

This is easy to demonstrate. Once again, I find myself indebted to Mythbusters:



This is a HEAT-style RPG warhead exploded inside a light structure. As you can clearly see, the explosion is focused (you can see the jet exit at left), but it's nowhere near 100%. The remainder is more than sufficient to completely obliterate light construction at close range.

This has been known forever. Modern tankers typically have a choice of HEAT-style or kinetic energy penetrator (e.g., APFSDS) rounds. When encountering lightly armored or unarmored targets, they use HEAT. Sure, the jet effect is probably going to be wasted completely, but there is still a substantial blast effect, enough to kill and injure at a surprising distance. Furthermore, this is for a military shaped charge which focuses onto a single line, as opposed to a demolition-style shaped charge which is a so-called "linear shaped charge" and focuses into a plane. The conventional demolition charge is a great deal less focused than the example above.

It should also be pointed out that the pressure to destroy structural steel is vastly higher than that to break a window -- typically on the order of 36,000 PSI, whereas a window may not survive even 2 PSI. If we insist on the ability to destroy columns without damaging windows nearby, we are talking about a stupendously effective focus, one that does not exist in reality. If it did, I can easily imagine a wide range of useful applications for such a technology.

Pressure isn't the whole story anyway. This is just another example of untrained individuals reaching past their expertise, and being forced to think in terms of linear approximations, first-order guesses, and so on. In an actual shaped charge attack, it is the actual momentum of the driver mass (the copper liner) coupled with the extremely high strain rates that result that cause fracture, spalling, and rupture of the target. Pressure also doesn't like to stay put -- even if we could contain the primary blast 100%, the reflected shockwaves from the steel surface would likely have enough power to break windows. So would pieces of the copper jet, which then bounce around inside the target just like bullets. The noise alone might be enough to break windows, as might the vibration.

In short, to claim the magic of shaped charges means demolition that preserves nearby windows is not merely ignorant, it is in fact indicative of a rather limited or biased imagination that borders on incompetence.

Nice to see you again, Tony. I really wish you'd find a healthier hobby. You've got some smarts, you just need to use 'em better.

This is all a derail, and a happy one, because I am learning so much from it. Thanks Ryan, Ozeco, and Sword of Truth!

 

[Tony Szamboti]

The temperature of the copper extrusion is highly variable. Nearly all of the heating is due to strain energy in the extrusion itself. Furthermore, the jet is at such high kinetic energy that its temperature is hard to sense -- and indeed difficult to define. Depending on the mission, one might actually attempt to tune the temperature of the copper jet, subtly altering the geometry until you got precisely the right working temperature, and thus the correct mix of strength, ductility, contact friction, abrasiveness, and secondary (heat) effect on the target.

Anyway, Sword Of Truth is of course quite correct, and Tony is of course quite full of nonsense. While it is indeed true that a shaped charge focuses its energy, and the shock wave will be strongest along that focus, it is complete madness to think there's effectively no damage away from the axis of the focus.

This is easy to demonstrate. Once again, I find myself indebted to Mythbusters:



This is a HEAT-style RPG warhead exploded inside a light structure. As you can clearly see, the explosion is focused (you can see the jet exit at left), but it's nowhere near 100%. The remainder is more than sufficient to completely obliterate light construction at close range.

This has been known forever. Modern tankers typically have a choice of HEAT-style or kinetic energy penetrator (e.g., APFSDS) rounds. When encountering lightly armored or unarmored targets, they use HEAT. Sure, the jet effect is probably going to be wasted completely, but there is still a substantial blast effect, enough to kill and injure at a surprising distance. Furthermore, this is for a military shaped charge which focuses onto a single line, as opposed to a demolition-style shaped charge which is a so-called "linear shaped charge" and focuses into a plane. The conventional demolition charge is a great deal less focused than the example above.

It should also be pointed out that the pressure to destroy structural steel is vastly higher than that to break a window -- typically on the order of 36,000 PSI, whereas a window may not survive even 2 PSI. If we insist on the ability to destroy columns without damaging windows nearby, we are talking about a stupendously effective focus, one that does not exist in reality. If it did, I can easily imagine a wide range of useful applications for such a technology.

Pressure isn't the whole story anyway. This is just another example of untrained individuals reaching past their expertise, and being forced to think in terms of linear approximations, first-order guesses, and so on. In an actual shaped charge attack, it is the actual momentum of the driver mass (the copper liner) coupled with the extremely high strain rates that result that cause fracture, spalling, and rupture of the target. Pressure also doesn't like to stay put -- even if we could contain the primary blast 100%, the reflected shockwaves from the steel surface would likely have enough power to break windows. So would pieces of the copper jet, which then bounce around inside the target just like bullets. The noise alone might be enough to break windows, as might the vibration.

In short, to claim the magic of shaped charges means demolition that preserves nearby windows is not merely ignorant, it is in fact indicative of a rather limited or biased imagination that borders on incompetence.

Nice to see you again, Tony. I really wish you'd find a healthier hobby. You've got some smarts, you just need to use 'em better.

Hi Ryan.

You are being speculative in much the same way Sword of Truth is. The pressure at a distance follows the inverse square law and is nowhere near the values you gave even a short distance away as it decays rapidly. This is why cluster bombs are used with each having its own charge. The comparison of the omnidirectional blast of the RPG in a tiny trailer is hardly comparable to some form of linear shaped charge on column 79 in WTC 7. The omnidirectional components of the linear shaped charge would be significantly less than the directional component and could have easily decayed to a less than capable of breaking windows value well before reaching any windows from column 79.

Sword of Truth is making an unsupported statement by insisting any charge on column 79 would break all of the windows in the vicinity.

 

[R.Mackey]

Pressure isn't the whole story anyway. This is just another example of untrained individuals reaching past their expertise, and being forced to think in terms of linear approximations, first-order guesses, and so on.

You are being speculative in much the same way Sword of Truth is. The pressure at a distance follows the inverse square law and is nowhere near the values you gave even a short distance away as it decays rapidly. This is why cluster bombs are used with each having its own charge.

Thanks for making my point so succinctly. You make a great "straight man."

 

[Tony Szamboti]

Thanks for making my point so succinctly. You make a great "straight man."

My original point was that the directional shock wave would have possibly been capable of breaking the windows at a distance, while the omnidirectional components were not and that may be why we see four windows broken which were in the direction normal to the north and south faces of column 79.

Since you are here I might as well ask what you think of the NIST walk-off failure now?

 

[ozeco41]

 

[ergo]

I stated that thousands of charges would have been necessary to bring down WTC7.

It never seems to sink in with bedunkers why this argument -- from their side -- is nonsensical.

BTW, misquoting Harrit -- not that it matters.

 

[ergo]

Well, at least ozeco now openly acknowledges where he fits into the discussion here.

I suspect he may have got the NIST agreeing answer for wrong reasons. I will study his findings in more detail - not for some time I am in Fiii on a holiday.....

So don't take Enik's work as definitive proof at this stage.

I will return.

 

[ergo]

I enjoy being a layperson and taking an allegedly qualified engineer to the woodshed even more. It's quite gratifying.

Tony, were you aware that SoT has these thoughts about you?

His antisemtism is merely peripheral.

To what? Yours? I don't doubt that whatever you're talking about, yours is much, much bigger. Just because.

 

[Sword_Of_Truth]

It never seems to sink in with bedunkers why this argument -- from their side -- is nonsensical.

It never seems to sink in with twoofers that while they scream and bitch and whine that fire can't melt steel, and that only a controlled demolition could have brought the towers down, they scream bitch and whine even louder at any suggestion that their theory of 9/11 includes a controlled demolition.

BTW, misquoting Harrit -- not that it matters.

No I didn't. I provided the exact quote and the link to the interview so you can check it yourself.

You apparently prefer your moral character down in the gutter next to Tonys.

 

[Tony Szamboti]

Tony, were you aware that SoT has these thoughts about you?

I honestly don't know how he/she can be congratulating him/herself here after erroneously claiming that the force in a linear shaped charge is the same in all directions, in an attempt to justify his/her unsupported claim that there couldn't have been a shaped charge on column 79 as it would have blown out all of the windows in the vicinity.

 

[LSSBB]

I honestly don't know how he/she can be congratulating him/herself here after erroneously claiming that the force in a linear shaped charge is the same in all directions, in an attempt to justify his/her unsupported claim that there couldn't have been a shaped charge on column 79 as it would have blown out all of the windows in the vicinity.

Somebody got that Wooooosh parrot for Tony?

 

[Sword_Of_Truth]

Sword of Truth is making an unsupported statement

Mackey paid you a compliment and tried to encourage better behavior from you, and I almost felt about how snarky I've been.

Until you started lying again.

My comments were well supported with numerous real world examples. Even your comrade Miragememories provided a particularly damning example of why your claims are utter nonsense.

by insisting any charge on column 79 would break all of the windows in the vicinity.

If you're not working in your chosen field at this time, it shouldn't be a mystery to you why. But if you actually believed that and could explain it adequately put it down on paper (and actually get it reviewed and published for real this time) you could approach Mark Loizeaux and explain to him how to save he and his clients millions in expensive and time consuming, and according to you unnecessary, safety precautions like large security/safety zones and having to pay a half dozen glass companies to be on hot standby when windows in other buildings than the ones being demolished break from the backblasts.

You could also win millions of dollars for the family of 12 year old Katie Bender when you explain how she wasn't really killed by debris from the botched Canberra Hospital implosion that flew half a kilometre across an entire lake and that it was really something else.

 

[cjnewson88]

So we're back to hush-a-boom high explosive (except when it's not) bombs? Oh dear..

 

[Sword_Of_Truth]

Anyway, Sword Of Truth is of course quite correct, and Tony is of course quite full of nonsense. While it is indeed true that a shaped charge focuses its energy, and the shock wave will be strongest along that focus, it is complete madness to think there's effectively no damage away from the axis of the focus.

Tony is effectively claiming that you can lay a brick of RDX on your coffee table and destroy your living room (more likely your entire home), but if you carve a notch along one side of it, it will only destroy half your house.

As you rightfully pointed out, this is what we in the psychiatric community refer to technically as "stark raving bug-@#$%".

It should also be pointed out that the pressure to destroy structural steel is vastly higher than that to break a window -- typically on the order of 36,000 PSI, whereas a window may not survive even 2 PSI.

You can drive a half-ton pickup truck at a 100 miles per hour into a modern skyscraper structural column and possibly warp it slightly. But a window can be destroyed by the errant toss of a softball by a small child.

If we insist on the ability to destroy columns without damaging windows nearby, we are talking about a stupendously effective focus, one that does not exist in reality. If it did, I can easily imagine a wide range of useful applications for such a technology.

I proposed a "brute force" solution a few pages back. Basically a big-ass block of concrete the size of a washing machine for each charge like the one Loizeaux was pictured holding encased in additional layers of steel and concrete to minimize spalling. We could even mold baffled channels into the block to allow the release and attenuation of the energy of the expanding gasses.

If we were to assume some kind of small, lightweight, unobtanium casing for the charges, that would be even worse for Tonys hallucinatory nin-jews. Being small and lightweight they would effectively turn the 8,000+ charges into small ultra-short burn duration solid fueled rockets, turning WTC7 into a 47 story Stalin's Organ. These mythical casings would be landing all over Central Park and upper Manhattan.

This is just another example of untrained individuals reaching past their expertise, and being forced to think in terms of linear approximations, first-order guesses, and so on.

I'm a layman and I'm doing ok.

This only means, however, that neither Tony nor his lay-toadies have an excuse for not understanding the material being explained to them.

 

[ozeco41]

Tony is effectively claiming that you can lay a brick of RDX on your coffee table and destroy your living room (more likely your entire home), but if you carve a notch along one side of it, it will only destroy half your house....

..and it means that us military engineer types using shaped charges to cut steel didn't need to hide behind barriers to protect us from the back blast. And all those bits that whistled over our heads were either our imaginations OR pure coincidence from some other activity which seemed to happen every time we used the shaped charges.

Somehow I think I will stay with the conventional understanding. Even if Tony was prepared to put his money where his mouth is and stand unprotected behind an exploding shaped charge I would still retreat the distance and behind cover.

BTW did you notice the couple of comments about Tony's claim of "most" - pgimeno highlighted it and I put a ball park around it and Ryan provided some real numbers for target damaging. AND there was at least a 100:1 gap in the dangerous direction which true to style Tony ignores. That should be far more than enough to break windows even allowing for inverse square diminution of effects.

...As you rightfully pointed out, this is what we in the psychiatric community refer to technically as "stark raving bug-@#$%"....

...there are two more likely explanations but neither of them does Tony any credit. His latest comments should even be demeaning to ergo who tried to support him.

...I'm a layman and I'm doing ok....

You sure are - keep up the good work.

...This only means, however, that neither Tony nor his lay-toadies have an excuse for not understanding the material being explained to them.

Remember "There's none so blind as they that won't see." - usually attributed to Jonathon Swift though often used in multitudinous variants.

 

[ergo]

I honestly don't know how he/she can be congratulating him/herself here after erroneously claiming that the force in a linear shaped charge is the same in all directions, in an attempt to justify his/her unsupported claim that there couldn't have been a shaped charge on column 79 as it would have blown out all of the windows in the vicinity.

Even if there could have been a shaped charge, it still would take thousands of charges to bring down WTC 7, according to our woodshed friend. Just cutting col. 79 wouldn't do it.

Oh, wait a minute...

 

[ergo]

Remember "There's none so blind as they that won't see."

.
.

 

[Christopher7]

So we're back to hush-a-boom high explosive (except when it's not) bombs? Oh dear..

Real suspects of 911
Paul Bremer: His offices were hit when the plane hit the North Tower, but he did not go to work that day.
http://www.youtube.com/watch?v=Xpw7fUj11bA&feature=youtu.be
On Board of directors of:
1:53 "Komatsu - In July 1996 patented a nano-thermite demolition device
Patent 5532449 Issued on July 2, 1996

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and an apparatus which can demolish a concrete structure at a high efficiency while preventing a secondary problem due to noise, flying dust and chips, and the like.
http://www.patentstorm.us/patents/5532449/description.html

This device could melt/destroy concrete, It would be a fairly simple matter to make a device to melt/cut steel. We can only speculate about specifics but the possibility that nano-thermite devices could be used to destroy the TT cannot be denied.

 

[cjnewson88]

Real suspects of 911
Paul Bremer: His offices were hit when the plane hit the North Tower, but he did not go to work that day.
http://www.youtube.com/watch?v=Xpw7fUj11bA&feature=youtu.be
On Board of directors of:
1:53 "Komatsu - In July 1996 patented a nano-thermite demolition device
Patent 5532449 Issued on July 2, 1996

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and an apparatus which can demolish a concrete structure at a high efficiency while preventing a secondary problem due to noise, flying dust and chips, and the like.
http://www.patentstorm.us/patents/5532449/description.html

This device could melt/destroy concrete, It would be a fairly simple matter to make a device to melt/cut steel. We can only speculate about specifics but the possibility that nano-thermite devices could be used to destroy the TT cannot be denied.

No where in that link does it state "nano-thermite". Also, the towers were not concrete. Double fail C7.

So Paul was on the executive board for Marsh & McLennan, which had offices in the South tower, not the north. Did Paul have an office in the tower? We don't know if he even worked there. Saying he took a day off on 9/11 is completely irrelevant if he didn't even work in the towers.

My god that entire video is complete garbage. People are still saying Marvin Bush ran security for the towers??

 

[Oystein]

Even if there could have been a shaped charge, it still would take thousands of charges to bring down WTC 7, according to our woodshed friend. Just cutting col. 79 wouldn't do it.

Oh, wait a minute...

Are you claiming that is is possible, even plausible, that a single charge to column 79 would lead to exactle the progressive collapse of WTC7 that we witnessed - including the EMP drop, the few seconds till the screenwall and the WMP came down, Chandler's period of about freefall of the north wall, Gage's "symmetry", etc? Or do you disagree that this is possible or plausible?

Tony, how do you answer that question?