No misdirection on my part as it has only now clicked with me exactly who Morgan Reynolds is – the ‘no planes’ and ‘DEW’ guy. I do not take his lawsuit against NIST seriously, thus my putting it out of mind. Yes, I need to annotate my original statement: -


*Nobody barring a government disinformation artist intent on making all conspiracy theorists look completely unreasonable in a public case that a child could dismember.

I have yet to find a single serious conspiracy theorist who agrees with ‘no planes’ or ‘DEWs’. So, the real question here is: of all the good and most popular evidence indicating 9/11 to be a false flag operation, why is it ‘coincidently’ (that word again) an ex Bush administration official who happens to be bringing these ridiculous theories to light?



It should be up to a jury to decide, after viewing all evidence, whether the facts fit an inside job (which they absolutely do ). I do not believe in the first place it is possible for any 'joe public' to bring a case to court regarding the 9/11 inside job. Or are you suggesting that by dropping in at my nearest police station and reporting what evidence I know, we will have a trial? Do be serious.

Then you could put the question to me - how did Morgan Reynolds get his case against NIST to court then? Well, maybe someone within the government and associated with the inside job wanted this particular lawsuit to be put forward. Afterall, we can agree it does the official story far more good than harm.

Anyhow, I am going to leave this nonesense to the "US Court Unseals 2nd 9/11 "Inside" Job Case" thread. I am enjoying flyingswan's wild theories and failing attempts to defend the B&Z paper too much on this thread.

So you are still claiming it is a CD because it looked like a CD (fast collapse, straight down), and it is a CD because it didn't look like a CD (fires lasting for hours, no sounds of explosions, parts at top going several seconds before main collapse). And you say my theory is far-fetched.

Just because you fail to understand the concept of a conservative assuption, it does not mean that either B&Z or the referees who checked their paper suffer from the same disability.

There you go again - imposing your opinions on structural engineers when you don't have the confidence in your theories to go and talk to a single one.

It isn't about stopping debris, it's about stopping the top half of a building. The "inside job" argument is that the lower part of the building should have provided more resistance. B&Z show that even the strongest part of the building is completely inadequate to stop it. Why you think the secondary structure should do any better is beyond me.

Neither of your scenarios results in the boulder being halted, which is what it is all about. In any case, in a more realistic analogy it isn't a boulder, it's a second tree, and it starts with the two trunks directly in line as the upper tree falls on the lower.

You say that something other than the upper columns falling on the lower columns could halt the collapse, but you don't say what. If the columns miss and pass each other by, then their secondary structures will meet. The secondary structures such as the columns' cross-bracing do not have the strength to stop a fall, so they will break. The columns will not stand without their cross-bracing, so will fall too. Either way, you do not stop the collapse.

This is of course a matter for you to take up with the supporters of Reynolds and Woods that post here. Suggest you take that view to the relevant threads.

Edit to add: Let's see if you have any success in convincing them of the error of their ways! I don't think you'll have any more success with them than I have with you, and for the same reason.

the entire b&z anaysis is inadequate because they are basing their calculations on the "presumption" that the floors above dropped through 12ft of empty space as if one floor entirely disappeared into thin air-- the first tower to collapse only had minor core damage and in fact had most of the fuel ejected out the other side and was ignited and consumed on impact-- the damage to the perimeter columns was even less that the core,percentage wise,and when you figure in the elevator shafts,stairwells,drywall office structures and furniture the paper becomes completely busted and bogus to the point of absurdity

According to the Purdue simulation, about a quarter of the core columns were broken in the initial impact. That is hardly "minor core damage".

Why do you think office furniture could play any part in halting a collapse?

the bottom line is that the b&z paper relies on the complete absence of the material in order to be a woking hypothesis-- 3/4 of the core intact and even more of the perimeter do not equate a freefall drop of 12 ft which is what the paper relies on to explain the freefall collapse without resistance-- as far as common sense is concerned the b&z anaysis is BUSTED!

Common sense is not generally a good guide in technical matters. That is why people with no technical qualifications are not allowed to construct high-rise buildings.

Instead of common sense, apply some basics of structural engineering to the situation:

A building with a quarter of its main structural elements removed has lost a large portion of its safety margin of strength. Elements near the damaged parts carry more than a proportional share of the extra load. In these circumstances it can take very little structural weakening due to fire to spread the damage so that another element fails. Spreading the damage one element at a time further reduces the safety margin. Eventually you get to the point where each failure immediately overloads one or more of the remaining elements and the structure starts to collapse. A collapsing structure puts all sorts of loads on the remaining undamaged elements that they were not designed to take. A collapse will only be halted if, once the damaged region has closed up, the undamaged parts are strong enough to absorb the kinetic energy of the collapsing parts. B&Z show that this was not the case for the towers, by a large margin.

absolute absurdity!! wolf,jowenko,jones and many others have "PROVEN" that common sense is the rule-- please explain the logic in "disappearing" an entire floor equal to 12ft of undamaged load bearing box and perimeter columns,elevator shafts and stairwells other than to make up for the explsive force necessary to create the collapses witnessed and recorded?

Absolutely wrong. They have "proven" why common sense has nothing to say in such matters! One wonders why Steven Jones have still to publish his so called scientific findings in a peer reviewed journal so his peers can comment on them. My guess is that he'd rather not have his peers comment, as they would most likely peel his arguments completely apart! I still stand fast on that there is a reason why the whole civil engineering department at BYU as a whole denounced his work. His work is therefore, in my honest opinion, nothing more than an idea, but an idea he'd rather not have reviewed in detail and that makes him completely unreliable as a source.

And I think that is a notion that is shared with many. By all means of respect, if I were you I would look rather critically at my sources before hanging my hat on them.



Nothing disappeared! How hard is it to understand that 29 floors crashing onto the 28th floor will see no difference whether there is furniture and drywalls in the 12 feet between them? Everything in the path will be crushed. And that inner and outer columns had been damaged to the extent where structural integrity was severely compromised and loss of integrity finally occurred when the fires had raged for a while. A few simple facts:

* Impact from airliner: energy equivalent ~800kg of TNT (not counting jet fuel ignition).
* Impact from top 29 floors onto the 28th floor: energy equivalent ~750kg of TNT.

So the airline impact will have incurred extensive damage and definitely enough damage to severely comprise structural integrity. And when the loss of structural integrity occurred, the forces in play were more than enough to take down the rest of the structure. It is basic physics and simple civil engineering. Simple comparison: Oklahoma City bombing.

Aerial photo lifted from Wikipedia (http://upload.wikimedia.org/wikipedia/en/8/8e/Murrah_Building_-_Aerial.jpg):



Clearly a lot of destruction caused by the truck parked in the front of the building. That truck contained 2,300 kg of fertilizer and nitro-methane mixture, that detonated and made the damage shown in the above photo. Now imagine the damage the energy equivalent of ~800kg of TNT will incur when detonated spanning only a few floors and directly on the side of a building, if not somewhat inside. To me it is pretty obvious that the damage could take down a building as the WTC.

That also begs the question:

Simulations and calculations showing that the buildings were brought down due to the airplane impacts and the ensuing fires: published in peer reviewed journals.
Simulations and calculations showing that the buildings were brought down due to demolition/DEWs/etc.: NOT published in any peer reviewed journals.

Why? In my honest opinion the answer is straight forward. The former is well understood and backed up by physics. The latter is not backed up by anything but the assertions of non-experts calling themselves experts and fueled by people willing to listen to such "experts" with the notion in the back of their minds that they want the conspiracy to be there and thus any rational arguments against is thus easily discarded using various excuses. The latter would never pass a peer reviewed process.

Conclusion: the collapse is thus that the buildings were brought down due to the airplane impacts and the ensuing fires, which is also the general consensus among the real experts that actually knows something about civil engineering and the physics behind it.

Best,
Badeskov

you are clearly a rookie on the oklahoma subject-- the fact that demolitions were used was as obvious as 9/11 and brig gen benton k partin completely ends all debate on that-- alex jones 911 the road to tyranny clearly exposes the truth beyond doubt that oklahoma was a psy-op and test on media manipulation--here is alot of UM info from a thread that was erroneously closed that i would of loved to have discussed the details of with you in but can only be used a reference now-- there was no refuting the data -- Oklahoma Murrah Demolition

By all means of respect, but no wonder that thread got shut down. You had no arguments whatsoever to put forth! You can in no way argue your way out of this one. The Oklahoma bombing was the result of a terrorist attack and that should be pretty obvious. But that is not the topic here, although you obviously do not take well to rational arguments.

So lets take another example, the 1983 Beirut USMC barracks bombing. A truck managed to crash through security and smash into the lobby where the driver detonated ~5,400 kg of TNT, which leveled the building (from Wiki):



That was ~7 times more TNT than the energy equivalent from the aircraft impact ito the WTC, however, this detonation resulted in an instantaneous collapse when it ripped through the all the support pillars. Also from Wiki:



While this blast was significant larger, it also ripped through a structure that was stronger than that of the WTC.

...ooooor, was this also a conspiracy with a controlled demolition?

Then there is the bombings of the US embassies in Africa in 1998. Here from the bombing in U.S. embassy bombing in Tanzania (from CNN: http://www.cnn.com/interactive/us/0103/emb....exclude.html):




Clearly substantial damage was incurred, albeit nowhere near what was seen in WTC or the Oklahoma City Bombing. The estimated amount of TNT in the Nairobi bombing was 500kg and should be roughly the same in the Dar-es-Salaam (Tanzania) bombing. Both bombs were detonated outside of the embassy compounds, nonetheless inflicting severe damage. In Nairobi an adjacent office building completely collapsed. So I ask again, if the energy equivalent of 800kg of TNT was detonated on the face of the WTC (or a little inside), spanning only a couple of floors, that would not incur significant structural damage?!?! Or are the US embassy bombings part of the conspiracy also?!?!?!

Honestly, I am still waiting for a single argument from you countering what I have said.

Best,
Badeskov

Edited to add CNN link.

When columns and perimeter walls are broken or loaded beyond their design limits they are not undamaged, they are very damaged indeed. That is why they no longer stop the top half of the building falling on to the bottom half.

On your argument you could load a column indefinitely and it would never give way, because there is always the "undamaged" column between the load and the ground. I suggest you do a little experiment - get a drinks can and load weights on to it, stand on it yourself as part of the weight if you feel like it. What eventually happens?

hmm... lets see-- whose credentials are more worthy of my consideration in establishing an understanding of what happened at oklahoma...a UM noob or BRIGADIER GENERAL BENTON K. PARTIN-- not a very difficult decision...i think you better read his analysis before putting your faith in the mainstream media version and then look at the facts--oklahoma was an obvious psy-op inside job -- learn the facts by wating this google video 911 The Road To Tyranny

pff... i suggest "you" do a little experiment by reading the analysis detailing why explosives must have been used by the physics prof from BYU Steven Jones or listening to the presentation by iraqi veteran and demolition expert Torin Wolf called "taking the red pill"-- you can find both here in this thread i started that includes the eye witness testimony of multiple firefighters and a demolition expert cooberating wolf and jones
The 9/11 False Flag Inside Job

Actually, I would trust the FBI people investigating the incident, and that makes the Oklahoma City bombing a terrorist attack and not an inside Government job...

Best,
badeskov

And why exactly is it we should trust a professor of nuclear physics publishing a civil engineering paper in a non-peer reviewed journal (a field completely outside his own), while the civil engineering experts denounce him, the same people that actually knows enough to denounce him?

The answer is, we shouldn't. He has made a sloppy left hand job and doesn't want experts to give comments, as they would slice his work to pieces. In this he has lost all credibility and shouldn't be referenced if some common sense and critical thinking skills were applied.

So instead of just pff'ing off flyingswan's little experiment, I suggest you try and do what he suggested. You might actually learn something Then again, arguments that one knows one cannot win can always just be pff'ed off instead of engaging in a constructive dialog (what a wasted of time and resources, eh).

Best,
Badeskov

Here's one for you.

If the cunning, evil government was indeed behind the attacks, why would they make such an apparently obvious blunder and demolish a building in full view of everyone?

Apparently the SAME goverment was brilliant enought to mastermind an elaborate plan to kill 3000 innocent americans, supposed to give it a reason to go to war, AND yet stupid enough to choose a building and demolish it when it had no obvious cover to do so.

Building 7 collapsed because of its unusal design and the fact a plane exploded above it.


Get over it, and stop causing such disrespect to the people who died.

What has either of them to say about your claim that columns can't collapse at all? Nothing. This is your claim, so if you can't defend it just admit the fact instead of posting irrelevent links.

Both your "experts" have no structural engineer qualifications at all. Look at Wolf's "rebuttal" of the near free-fall collapse. He says it should have taken longer because each floor should have taken 0.5 seconds to break. Where does he get that figure of 0.5 seconds? He doesn't say. Could that be because 0.5 seconds was his own invention?

He says that no comparable building has ever collapsed due to fire alone. So what. He completely ignores the structural damage from the impacts which is why the subsequent fire caused the collapse.

Experimental evidence beats opinion every time. You have an opinion about why a collapse couldn't happen, I have an experiment that shows you are wrong.

All three building collapses, in particular WTC7, shared most characteristics of a controlled demolition. The weight of these characteristics points out a demolition despite the few differences from a standard demolition, ie timing and type of explosive/cutting charges used. It really is not so complicated to understand.



Yes the strongest part of the building is perhaps inadequate to stop a fall when more force is applied to that part than could ever have impacted it! Applying the impact forces to the correct areas is vital. The entire building is dependant on the main columns, though the main columns are not entirely dependant on the rest of the building.

Flyingswan, you believe the assumption that all impact forces go into the columns is fair. If we made the assumption all mass fell outside of the building, would this be fair? Why?



No this is the point I am making – it is not necessarily about halting the falling mass; it is about stopping and/or limiting the collapse. There is a difference.



It is impossible for the secondary structure to be impacted, broken and then for the main columns to follow afterwards all at virtually freefall speed. The Tower collapses were due largely to a failure of the core columns, of that I have no doubt. A failure that the official story cannot account for.



I believe Sunofone was referring to the South Tower where the airliner impacted at an angle towards one side of the building face, by and large missing the core: -



Speaking of which – what does anyone think of the fact Purdue simulated the North Tower impact but declined to do the same for the South Tower where less damage would have been caused?



Just a correction here – neither of the Towers had quarter of their main structure removed. With the buildings being 110 storeys, a quarter of columns over half a dozen floors if we are generous, would only equate to just over 1% of the total structure of each Tower.



Bad experiment as, to state the obvious, a drinks can is a hollow cylinder whereas the columns in the Towers were solid through. It is reasonable that individual columns could bend if overloaded and progressively weakened, but for all columns to simultaneously crumple like a drinks can?

Anyone would think it a wonder the Towers stood for over 30 years the way some people talk of them as toothpicks, drinks cans, house of cards or pancakes.

bldg 7 had no plane impact it!

imo disrespect is allowing atrocities in afghan and iraq in the name of the victims by the very people that murdered them

I'm aware building 7 had no plane hit it. If you read my post, you would see it says "above".


I see you and the other CT's forgot to answer my question. So here it is again:

If the cunning, evil government was indeed behind the attacks, why would they make such an apparently obvious blunder and demolish a building in full view of everyone?

I'm waiting.

to horrify people...

Crashing 2 planes into WTC 1 and 2 then detonating explosives inside both to bring them down and at the same time crashing another plane another into the Pentagon wasn't horrifying enough?

They had to add randomly demolishing a smaller building that clearly wasn't hit by a plane? Just to add to the impact eh?

Don't you think that raises more problems for the government than it's worth?

Try again.

I don't want to intrude in your discussion, just wanted to say that if the depicted schematic is correct with respect to angles and scale (which it looks to be), then the impacting aircraft would still severely damage to core structure, in my honest opinion.

Cheers
Badeskov

What's horrifying is AFTER the "attack"....when george bush was standing at ground zero saying how they were gonna go after the people who did this....Does this mean they go after themselves?Or maybe,they should do like O.J. and look for the real terrorist on the golf course.Naw,let's got git some oil!(and kill that bad man that wanted to kill my daddy)Hey,at least they now had a reason...even if the iraqi people had nothing to do with it..Now wait and see how long it takes for Iran to be the next target...so many terrorist.Someone better quit trying to play god before the real one steps up and smacks one out of the ballpark...if ya get my meaning.Ahh,screw it.Who cares?

You should know such people well enough by now. I can just imagine the discussion after rigging WTCs 1 and 2:

Conspirator 1: Aah, finally finished buddy. I think we did a good job!
Conspirator 2: Yes, now I think we deserve that beer. But waddawe do with the remaining charges? *looking back at inconspicuous florist van parked a 100 yards away*
Conspirator 1: We have more charges?!?! *looking around for another innocent building with that look that only kids accidentally stumbling over some candy in the kitchen cupboard can have *

And the rest is history, as they say.



Indeed it would, it it would be absolutely ludicrous to do so.

Best,
Badeskov

I haven no idea what you are trying to say in that ramble, but what I got from it is that you are a bush-hater with a simplistic and ill-informed view of a complex issue that is the Iraq/Afghanistan war. The only thing that even remotely ties your response to my question, which by the way has still not been answered, is the word "horrifying'.

Well thats your shot. Any other 911 conspiracy theorists want to have a crack at my question?

Still waiting.

Yes I agree much damage would be caused to the South Tower, though not close to the amount of core column damage in the North Tower: -



Why was the North Tower impact with maximum core column damage simulated by Purdue but not the South Tower which would have shown smaller core column damage and only on one side? Is this another of those coincidental ‘just because it was’ things?

Further to the above, we know that the top of the South Tower began to topple. The initial tilt was to the side and corner of the building damaged by the airliner impact: -



This is good so far; what we would expect to happen should the Tower begin a fall (in reality, limited damage and random fire could never have begun such a collapse in the first place - I am just humouring the official story in this instance). But in the next instant everything about the collapse falls out of line with what is to be expected - the momentum of the tilting block somehow stops and the collapse proceeds virtually symmetrically straight down. How can this happen?

I know a way in which it could happen – if the core structure of the South Tower was cut on a floor lower than the impact zone. This would first remove the pivot that the tilting block is acting on and second allow the structure to continue its collapse virtually symmetrically and at near freefall speed.

Or perhaps the perpetrators wanted WTC7 removing for a purpose? It is known the building contained CIA offices, Department of Defense, Secret Services and an emergency command bunker. This is all confirmed in the FEMA report (beware large file link) on WTC7. A better place to plan and execute the 9/11 false flag operation I cannot think of.



Because apparently the perpetrators knew the public at large, presented with the biased Commission Report and preconceived conclusions of NIST, were gullible enough to believe airliners guided by Arabs brought the Towers down? Their beliefs have proven correct.

Why did the Towers need to be completely demolished? Because airliners making holes in the Towers and killing possibly hundreds of people before perhaps being repaired will not support a long term 'War on Terror' and invasion of the Middle East, whereas complete collapses killing thousands of people will. Also the cost of deconstruction/rebuild of the Towers, required at some point in the future due to asbestos problems, was estimated to be in the double-digit billions. By completely removing the Towers in a terrorist attack, that is a quick solution with the insurance companies covering most of the cost.

it had to do with silversteins insurance scam-- he used to only own bldg 7 but 90 before 9/11 the state of ny not only illegally sold him wtc 1 and 2 as the construction and upkeep had been completely tax subsidized which mean the taxpayers were paying it but no insurance company in their right mind would insure a bldg that was a known terrorist target and that had major previous damage-- silverstein invested a couple of hundred million in a questionable insurance deal that miraculously paid out 7 BILLION dollars and just recently i there is information surfacing that silversteins initial payments may not have even been received-- there are no problems when you manufacture reality through a cia controled media and a dumbed downed population too busy navigating a psycological maze looking for cheese

Or the remaining structure wasn't strong enough to act as a pivot and failed in turn. This is plausible as the forces imposed by the tilting structure would be immense and in a different direction to the main gravity forces the building was designed to withstand.

In my opinion the towers looked nothing like a CD - what CD starts near the top of a burning building, coincidentally just at the level where an airliner has hit the building? The only part that looks like a CD is the final collapse of WTC7, starting after the penthouse goes. The weight of the evidence - all of the towers and WTC7 until after the penthouse goes - are nothing like any CD, which is why you have to invent your ridiculous "CD but not like a CD" theory.

Apart from the fact that it manifestly didn't happen like that? The overwhelming majority of the upper part fell on the lower part. Whether it fell on the columns or the secondary structure is the point we were arguing.

Case 1: If the load all goes into the columns then the columns break.

Case 2: If it all goes into the secondary structure then that breaks. The columns cannot stand without the secondary structure, so they break too.

The end result is pretty much the same.

It looks to me that a major part of the aircraft, the port wing and its fuel, still hits the core. As to Purdue, I imagine the simulation was extremely expensive both in manpower to set up all the data and in computer time, so why repeat it for a generally similar situation?

A quarter of the structure at the impact levels, to be precise.

You can do the experiment with anything you please. I simply picked a drinks can as a common object that is fairly easy to break. I am not comparing the towers to drinks cans, but setting up a household-scale test of sunofone's contention that the building could not fall because there wasn't any empty space for it to fall into. A column, solid or hollow, will fail if you put a heavy enough object on top of it. Once it has failed the object will fall.

The same engineering principals apply to all structures - towers, toothpicks, drinks cans, house of cards or pancakes - it's just a matter of putting in the right numbers for strength and load. The fact that you quibble about this only serves to remind the engineers here how ill-advised you are to be satisfied with your understanding of structural engineering.

Why should the South Tower core which supported most of the structure for 30 years, was over-designed to carry more weight than ever necessary (factor of safety 2.25) and had managed to support the upper block as it tilted outside of the building footprint, suddenly fail? The block above the impact zone does not even initially fall as such; it tilts to the side – no additional impact force, no additional mass to support. If the core could withstand the initial tilting and the block had gained momentum sideways there is no reason this should not continue given a ‘natural’ collapse. Not that is, unless the core fell away from beneath the tilting block.

So that everybody can follow and make up their own mind - South Tower collapse/tilt video here and core column construction photograph: -



Viewing this photograph it is apparent the Towers were, relatively speaking, lightweight structures containing a lot of empty space within the core. You have to ask what mass was available to crush the core structure. The mass of the core itself? The core crushed the core? Ah yes because that is the official fairytale is it not – the Towers crushed themselves. It would be humorous were it not so pathetic.



Sudden onset, virtually symmetrical, near freefall, visible squibs, complete collapse – all like controlled demolition. Buildings do not by chance, due to limited damage and/or random fire, collapse imitating these characteristics of a controlled demolition. Especially not three times in one day when the actual damage effects suffered by each building varied so much.



Now apply your “it manifestly didn’t happen like that” argument to the B&Z paper – it applies equally as well to my theoretical assumption of the mass falling outside the building footprint as it does to the assumption of all impact forces going into the columns. Well done flyingswan, you have debunked the B&Z paper.

I was never arguing it fell on the main columns or the secondary structure or outside of the building – I argue ‘Case 3’ (see below).



Case 3: Some of the load goes into the columns, some goes into the secondary structure, most goes into the floors and some falls outside of the building.

Now there is no longer the required force to break the main columns. If the floors and/or supporting structure are removed this does not result in a near freefall collapse of the Tower core.



That is what I thought the official story would say – “it is just an unfortunate coincidence we do not have the funds or time to show you the South Tower impact where far less damage was caused than to the North Tower”.



That is more like it. This equates to approximately 1% of the structure as a whole. Yes people – a complete, virtually symmetrical, near freefall collapse due to 1% damage followed by random fire. Think of the time demolition teams could save if they knew this were possible!



Ok, here is a more realistic household-scale test. Make a structure from metal coat hangers and heat unequally at random points. Observe whether there comes a point the structure at a level quickly collapses, or whether in fact it bends and warps. Alternatively take a box shaped wire cage, heat and observe as previous.



Coming from the person who utterly failed in their prediction of the Bankers Trust building and has invented an unsupported wacko theory surrounding WTC7 including ‘bouncy’ columns, the above is a joke right?

When the upper part starts to tilt, its centre of mass also starts to move sideways. For this to happen a sideways force must be acting. The only place this force can act is through the "hinge". Building structures are not designed to carry large sideways forces, so it is hardly surprising if the hinge breaks and the upper part then simply falls.

You do love to demonstrate your lack of understanding of structures, don't you. The column elements at each level were designed to support the mass of the building above that level. They were not designed for the much higher dynamic loads of that mass falling on to them.

Buildings are not normally hit by aircraft or debris from another building either, and are not designed to withstand a fire indefinitely. Two of the buildings suffered similar damage and collapsed in the same way, the third suffered a different type of damage, a much longer period of fire and a different type of collapse. In spite of all these differences, to you they all look like CD, and the difference are because it was a new type of CD that didn't look like a CD.

Virtually symmetric near free-fall complete collapse will occur any time the building is tall enough to have a lot of potential energy and initial damage is sufficient, no matter what caused the damage. As to "squibs", what CD charges fire after the building starts to fall?

You don't appear to understand what I meant by secondary structure. I mean the cross-bracing elements that stabilise the columns. There is no way from the video evidence that the core structure of the top part - primary columns and secondary braces - fell outside the core structure of the lower part. Look at your picture, how far would it have had to have moved sideways? Given this, your third case is not applicable.

25% on one level only counts as 1% of the total if you then count the partially supported structure above that level as still fully functional. How much of the structure as a whole is destroyed in a CD? You are quibbling again.

My experiment was addressed to one point, sunofone's "no space to collapse into" argument.

If you want to make a scale model of the whole collapse you are going to have to do a lot more work than that. You are going to have to have similar construction techniques, you are going to have to work out your model's safety margin element by element and match the building, have similar damage, etc, etc.

Read my prediction of the Bankers Trust building again (reply #241 and comments in reply #395). I said I would not be surprised and I'm still not surprised. What "utterly failed"?

How about your unsupported wacko claim that a steel structural element falling on another one would stop dead?

The contradiction in that sentence has just struck me. On the one hand, you refer to debris from the towers damaging the Bankers Trust building which was across the street, on the other you describe as wacko the idea from my "internal collapse" theory that debris could spread part way across the same building it's falling in to damage the outer wall.

HOW TO DEMOLISH A HIGHRISE WITH SYMMETRICAL, FREE-FALL PERFECTION

OPTION A:

In this article, we'll find out how demolition crews plan and execute these spectacular implosions. The violent blasts and billowing dust clouds may look chaotic, but a building implosion is actually one of the most precisely planned, delicately balanced engineering feats you'll ever see.

Demolition blasters load explosives on several different levels of the building so that the building structure falls down on itself at multiple points. When everything is planned and executed correctly, the total damage of the explosives and falling building material is sufficient to collapse the structure entirely, so cleanup crews are left with only a pile of rubble.

In order to demolish a building safely, blasters must map out each element of the implosion ahead of time. The first step is to examine architectural blueprints of the building, if they can be located, to determine how the building is put together. Next, the blaster crew tours the building (several times), jotting down notes about the support structure on each floor. Once they have gathered all the raw data they need, the blasters hammer out a plan of attack. Drawing from past experiences with similar buildings, they decide what explosives to use, where to position them in the building and how to time their detonations. In some cases, the blasters may develop 3-D computer models of the structure so they can test out their plan ahead of time in a virtual world.

The main challenge in bringing a building down is controlling which way it falls. Ideally, a blasting crew will be able to tumble the building over on one side, into a parking lot or other open area. This sort of blast is the easiest to execute, and it is generally the safest way to go. Tipping a building over is something like felling a tree. To topple the building to the north, the blasters detonate explosives on the north side of the building first, in the same way you would chop into a tree from the north side if you wanted it to fall in that direction. Blasters may also secure steel cables to support columns in the building, so that they are pulled a certain way as they crumble.

Sometimes, though, a building is surrounded by structures that must be preserved. In this case, the blasters proceed with a true implosion, demolishing the building so that it collapses straight down into its own footprint (the total area at the base of the building). This feat requires such skill that only a handful of demolition companies in the world will attempt it.

Blasters approach each project a little differently, but the basic idea is to think of the building as a collection of separate towers. The blasters set the explosives so that each "tower" falls toward the center of the building, in roughly the same way that they would set the explosives to topple a single structure to the side. When the explosives are detonated in the right order, the toppling towers crash against each other, and all of the rubble collects at the center of the building. Another option is to detonate the columns at the center of the building before the other columns so that the building's sides fall inward.

According to Brent Blanchard, an implosion expert with the demolition consulting firm Protec Documentation Services, virtually every building in the world is unique. And for any given building, there are any number of ways a blasting crew might bring it down. Blanchard notes the demolition of the Hayes Homes, a 10-building housing project in Newark, New Jersey, which was demolished in three separate phases over the course of three years. "A different blasting firm performed each phase," Blanchard says, "and although all of the buildings were identical, each blaster chose a slightly different type of explosive and loaded varying numbers of support columns. They even brought the buildings down in different mathematical sequences, with varying amounts of time factored in between each building's collapse."

Generally speaking, blasters will explode the major support columns on the lower floors first and then a few upper stories. In a 20-story building, for example, the blasters might blow the columns on the first and second floor, as well as the 12th and 15th floors. In most cases, blowing the support structures on the lower floors is sufficient for collapsing the building, but loading columns on upper floors helps break the building material into smaller pieces as it falls. This makes for easier cleanup following the blast.

Once the blasters have figured out how to set up an implosion, it's time to prepare the building. In the next section, we'll find out what's involved in pre-detonation prepping and see how blasters rig the explosives for a precisely timed demolition.

In the last section, we saw how blasters plan out a building implosion. Once they have a clear idea of how the structure should fall, it's time to prepare the building. The first step in preparation, which often begins before the blasters have actually surveyed the site, is to clear any debris out of the building. Next, construction crews, or, more accurately, destruction crews, begin taking out non-load-bearing walls within the building. This makes for a cleaner break at each floor: If these walls were left intact, they would stiffen the building, hindering its collapse. Destruction crews may also weaken the supporting columns with sledge hammers or steel-cutters, so that they give way more easily.

Next, blasters can start loading the columns with explosives. Blasters use different explosives for different materials, and determine the amount of explosives needed based on the thickness of the material. For concrete columns, blasters use traditional dynamite or a similar explosive material. Dynamite is just absorbent stuffing soaked in a highly combustible chemical or mixture of chemicals. When the chemical is ignited, it burns quickly, producing a large volume of hot gas in a short amount of time. This gas expands rapidly, applying immense outward pressure (up to 600 tons per square inch) on whatever is around it. Blasters cram this explosive material into narrow bore holes drilled in the concrete columns. When the explosives are ignited, the sudden outward pressure sends a powerful shock wave busting through the column at supersonic speed, shattering the concrete into tiny chunks.

Demolishing steel columns is a bit more difficult, as the dense material is much stronger. For buildings with a steel support structure, blasters typically use the specialized explosive material cyclotrimethylenetrinitramine, called RDX for short. RDX-based explosive compounds expand at a very high rate of speed, up to 27,000 feet per second (8,230 meters per second). Instead of disintegrating the entire column, the concentrated, high-velocity pressure slices right through the steel, splitting it in half. Additionally, blasters may ignite dynamite on one side of the column to push it over in a particular direction.

To ignite both RDX and dynamite, you must apply a severe shock. In building demolition, blasters accomplish this with a blasting cap, a small amount of explosive material (called the primer charge) connected to some sort of fuse. The traditional fuse design is a long cord with explosive material inside. When you ignite one end of the cord, the explosive material inside it burns at a steady pace, and the flame travels down the cord to the detonator on the other end. When it reaches this point, it sets off the primary charge.

These days, blasters often use an electrical detonator instead of a traditional fuse. An electrical detonator fuse, called a lead line, is just a long length of electrical wire. At the detonator end, the wire is surrounded by a layer of explosive material. This detonator is attached directly to the primer charge affixed to the main explosives. When you send current through the wire (by hooking it up to a battery, for example), electrical resistance causes the wire to heat up. This heat ignites the flammable substance on the detonator end, which in turn sets off the primer charge, which triggers the main explosives

To control the explosion sequence, blasters configure the blast caps with simple delay mechanisms, sections of slow-burning material positioned between the fuse and the primer charge. By using a longer or shorter length of delay material, the blasters can adjust how long it takes each explosive to go off. The length of the fuse itself is also a factor, since it will take much longer for the charge to move down a longer fuse than a shorter one. Using these timing devices, the blasters precisely dictate the order of the explosions.

Blasters determine how much explosive material to use based largely on their own experience and the information provided by the architects and engineers who originally built the building. But most of the time, they won't rely on this data alone. To make sure they don't overload or under-load the support structure, the blasters perform a test blast on a few of the columns, which they wrap in a shield for safety. The blasters try out varying degrees of explosive material, and based on the effectiveness of each explosion, they determine the minimum explosive charge needed to demolish the columns. By using only the necessary amount of explosive material, the blasters minimize flying debris, reducing the likelihood of damaging nearby structures.

To further reduce flying debris, blasters may wrap chain-link fencing and geotextile fabric around each column. The fence keeps the large chunks of concrete from flying out, and the fabric catches most of the smaller bits. Blasters may also wrap fabric around the outside of each floor that is rigged with explosives. This acts as an extra net to contain any exploding concrete that tears through the material around each individual column. Structures surrounding the building may also be covered to protect them from flying debris and the pressure of the explosions.

When everything is set up, it's time to get the show underway. In the next section, we'll find out what final steps the blasters must take to prepare for the implosion, and we'll look at the implosion itself. We'll also find out what can go wrong in explosive demolition and see how blasters evaluate the project once the smoke has cleared.

The Big Bang
In the last couple of sections, we looked at everything blasters do to prepare a building for implosion. In addition to these measures, the blasters must prepare the people in the area for the blast, assuring local authorities and neighboring businesses that the demolition won't seriously damage nearby structures. The best way blasters can calm down anxious authorities is by demonstrating the firm's success with previous implosions.

To help the blasters work through this process, a blasting company may bring in an independent demolition consulting firm, such as Protec Documentation Services. Protec uses portable field seismographs to measure ground vibrations and air-blasts during an implosion. Brent Blanchard, an operations manager for the company, says that they also inspect surrounding structures prior to the implosion, so that they can help assess any damage claims following the blast. Additionally, Protec's staff videotapes the blast from multiple angles so that there is a record of what actually happened. Using data collected from previous blasts, the company's engineers can predict ahead of time what level of vibration a particular implosion may cause.

Once the structure has been pre-weakened and all the explosives have been loaded, it's time to make the final preparations. Blasters perform a last check of the explosives, and make sure the building and the area surrounding it are completely clear. Surprisingly, implosion enthusiasts sometimes try to sneak past barriers for a closer view of the blast, despite the obvious risks. With the level of destruction involved, it is imperative that all spectators be a good distance away. Blasters calculate this safety perimeter based on the size of the building and the amount of explosives used.

On occasion, blasters have misjudged the range of flying debris, and onlookers have been seriously injured. Blasters might also overestimate the amount of explosive power needed to break up the structure, and so produce a more powerful blast than is necessary. If they underestimate what explosive power is needed, or some of the explosives fail to ignite, the structure may not be completely demolished. In this case, the demolition crew brings in excavators and wrecking balls to finish the job. All of these mishaps are extremely rare in the demolition industry. Safety is a blaster's number-one concern, and, for the most part, they can predict very well what will happen in an implosion

Once the area is clear, the blasters retreat to the detonator controls and begin the countdown. The blasters may sound a siren at the 10-minute, five-minute and one-minute mark, to let everyone know when the building will be coming down. If they are using an electrical detonator, the blasters have a detonator controller with two buttons, one labeled "charge" and one labeled "fire." Toward the end of the countdown, a blaster presses and holds the "charge" button until an indicator light comes on. This builds up the intense electrical charge needed to activate the detonators (this is similar to charging a camera flash to build the necessary electrical energy to illuminate a scene). After the detonator-control machine is charged, and the countdown is completed, the blaster presses the "fire" button (while still holding down the charge button), releasing the charge into the wires so it can set off the blasting caps.

Typically, the actual implosion only takes a few seconds. To many onlookers, the speed of destruction is the most incredible aspect of an implosion. How can a building that took months and months to build, and stood up to the elements for a hundred years or more, collapse into a pile of rubble as if it were a sand castle?

Following the blast, a cloud of dust billows out around the wreckage, enveloping nearby spectators. This cloud can be a nuisance to anyone living near the blast site, but blasters point out that it is actually less intrusive than the dust kicked up by non-explosive demolition. When workers take down buildings using sledgehammers and wrecking balls, the demolition process may take weeks or months. In this time, a significant amount of dust is being kicked up into the air every day. When the building is leveled in one moment, on the other hand, all the dust is concentrated in one cloud, which lingers for a relatively short period of time. Nearby residents with allergies can leave the area for that one day and avoid the dust entirely.

After the cloud has cleared, the blasters survey the scene and review the tapes to see if everything went according to plan. At this stage, it is crucial to confirm that all of the explosives were detonated and to remove any explosives that did not go off. If a demolition consulting crew was on hand, the blasters review their vibration and air blast data as well. Most of the time, experienced blasters bring buildings down exactly as planned. Damage to nearby structures, even ones immediately adjacent to the blast site, is usually limited to a few broken windows. And if something doesn't work out quite right, the blasters log it in their mental catalog and make sure it doesn't happen on the next job. In this way, job by job, the science and art of implosion continues to evolve.

http://science.howstuffworks.com/building-implosion.htm

OPTION B:

- Wallop the building randomly with a wrecking ball, for at least 10-15 minutes.

- Stand back.

- Wait approx. 1 hr.

- Done.

Try an alternative OPTION B with more relation to what actually occured:

- Hit building with a large and fast moving object having sufficient kinetic energy to penetrate to and severely damage core structure.

- Add many tonnes of kerosene and ignite

- Wait approx. 1 hr.

- Done

Getting back to the original theme of this thread, I came across this link:
http://www.cooperativeresearch.org/entity....arry_jennings_1



This is what I've been saying all along - Barry Jennings must have lost track of time if he really thinks his "explosion" was anything other than the North Tower collapse.

There is absolutely no proof that the core columns were even damaged, let alone "severely".

But regardless of what condition the core columns were actually in...

There is no need for a plane to hit it. The damage and fires could be simulated with explosives. So..

- Detonate asymmetrically pre-planted explosives on a few consecutive floors near the top of the building to replicate the asymmentrical damage and fires.

- Wait approx. 1 hr.

- Done.


The resulting damage and fires can widely vary from building to building, but you will always succeed in achieving a symmetrical, free-fall collapse for every building, in about 1 hr.

So what's all this about controlled demolition being such a difficult operation, with highly specialized experts, taking weeks or months of work, and costing a small fortune???

It's silly to spend so much time studying the blueprints, selecting very precise locations for the explosives, and create split second timing sequences for detonating, etc.!!

There's the Purdue simulation of the impact:
http://www.purdue.edu/UNS/x/2007a/070612HoffmannWTC.html
I'll take state-of-the-art computational engineering tools as pretty good evidence.


Ah, you're joining the "CD because it looks like a CD and CD because it doesn't look like a CD" camp now.

The whole "inside job" argument is that you cannot achieve the observed collapse without carefully placed charges. Now you say that randomly placed explosives to roughly simulate an aircraft impact will do the job. If this is so, why do you need explosives at all, or are you now taking the "no planes" stance?

Or is this another of your notorious "jokes" that you only admit were jokes when queried about them?

there was no plane at wtc7?...thats what the threads about?...plain and simple the building fell without impact wheres the argument?

No, that quote was just trying to make turbonium's original OPTION B strawman argument look a little bit more like what happened to the towers. For WTC7 I would reword it somewhat:

- Hit building with some large and fast moving objects having sufficient kinetic energy to penetrate and severely damage structure.

- Add many tonnes of diesel fuel and ignite

- Wait approx. 6 hrs.

- Observe complicated collapse sequence apparently bringing the interior structure down several seconds before the exterior

- Done

Turbonium is trying to argue that OPTION A, a controlled demolition, would not produce the same results as OPTION B, damage and fire. For this argument to work, OPTION B has to drop the building as neatly as OPTION A. This is of course nothing like true for the falls of the towers, which severely damaged the surrounding buildings. It may be true of WTC7, but I haven't really researched this aspect. My own theory of how WTC7 fell would in any case pr