Well, the video is indeed biased but it doesn't matter. It is great footage.

Certainly. I disagree with the premise, but that is neither here nor there. I Do not find the arguments about the technical aspects to be well informed, is all. I understand why they are made, and how they would make sense seen from that particular perspective, but there are things about construction that are not addressed, and that are integral to understanding the official explanation.

The general lack of knowledge on exactly how high-rises are designed in order to survive fires is one of these things. There seems to be a general belief that these buildings are designed to take on a towering inferno without a problem. This is not the case. Similarly, there seems to be some idea that the floor joists either had to be melted, or not, in order to fail. Again, not the case.

There are many, many, aspects to the collapse. No single one is responsible for the fall. That is why I made this thread. Taken individually, all the points add up together. It is only when they are mashed together in a list and derided as having no answers that they seem suspicious.

Since you offered and answer any questions of mine about the footage, I have some for you.

1.) Why were there explosions minutes before the collapse? Where did they originate?
2.) Why was there smoke rising up from the ground level before the collapse? What caused it?

Right, Fluffybunny asked this on page 1. The nine explosions were actually the sounds of eight floors collapsing within the tower. The floor joists, stripped of their fire resistant coat, warped and pulled themselves from the brackets holding them to the wall. Normally, the other redundant joists would have taken up the slack, but in this case, with the entire floor ablaze instead of just one part of it, all the other joists were experiencing the same thing. The metal eventually sagged and the floors, no longer supported, collapsed into themselves, in what is referred to as pancaking, one floor slapping down on top of another, on top of another, etc. The eight collapsing floors pushed a large quantity of air down the elevator shafts, the same place that the jet fuel had fallen through in the original crash, blowing it out through the bottom, where it had burned through, creating what looked like a ground blast. Up above, where the eight floors used to brace the walls together, there was nothing but an eighty foot cube of walls. The collapsing floors overwhelmed the already weakened central structural supports, which caused all of them to give way near simultaneously. The outer walls, not designed to bear the load of the entire building, particularly not without the central support beams, collapsed within seconds, and the entire tower fell.

aquatus1,

You have got quite the imagination there. Honestly it sounds quite feasible on the surface, but I would like to see evidence such as a time scale as to when each thing happened, or evidence period, with a link. And this does not explain the explosions in the basement that hit just before, during and after the plane hit one of the towers. This, according to eye witness testimony from William Rodriguez.

http://www.911forthetruth.com/

This is a good discussion so far...

You can use the 911 video that has been linked to here a few times if you want a timescale. They show a seismic reading of the floors collapsing prior to the total collapse.

Honestly, that is about as far as I am willing to go, in terms of supporting evidence. See, I'm not trying to prove anything to you. I'm not trying to get you to give up conspiracies, or trust the government, or believe that terrorist brought down the towers. I can explain to you how the official story matches what is known about high-rise construction, but, honestly, what could I present to you as proof? If I showed you melted brace joints, what would that mean to you? If I showed you fire resistance determination manuals, what could you do with them? When you ask for proof, what is it that you are looking for? What sort of question do you have that I would be able to present something that you could understand? I am not saying that you are ignorant, but I simply do not know how much you you know about architecture, and therefore have no idea what would constitute proof to you.

So you are insinuating the twin towers were built to withstand multiple hits by commercial jets, but only ones that have expended all their fuel?

OK.

If you crash a large commercial airliner into a building, I'm pretty much it's going to cut into it. The WTC were suppose to be able to withstand a hit from a 747 judging by the steel and what not used, but open areas and windows leave any building vunerable.. If something like a jet were able to penetrate the buildings, they would have come down. Really think about it, Any other building in the world and it would have collapsed too. Pft, Conspiracy Theorists.

I know what you mean. Some times I wish I didn't know what I did about government corruption. It makes it difficult to know what is truth and what is not. I used to be a republican, and trusted the government, kind of blindly. I used to think people got where they were for doing good things and that conspiracy theories were unlikely because how could they fool the media, and all the smart people in the world. Now I know how the world really works, and I don't put faith in the media or government to be very reliable when it comes to the real truth. The corporate media and federal governmnet have no credibility in my mind. So who am I supposed to believe now? Sounds crazy but the the conspiracy people have more credibility to me then anyone. I try my best to verify what is said, and usually I can do it. And that means what the masses are told on the news is a lie! That's dangerous, and I hate it. This is a messed up world, if you are aware of the inconsistencies in the official story on just about anything.

^^ Scooby, conspiracy theorists have nothing better to do than try to see things which are not there. Personally I think the world would be better without them because all they do is complain how the world is in a shadow of corperate darkness. Most things they do is negative and struggle for Anarchy when they don't even know what the government does for the people and how it works/how much power it actually has. pft, pft Pft, PFT

No, conspiracy believers are people who know that the corporate news lies, and searches for the truth elsewhere. When they find it, since it's not mainstream, others assume it's a wacky theory. Many times it can be, but many times it's not. The problem I have is that I can't offer any solutions that will have a chance in hell of working to correct the situation. The only thing you can really do is inform the populace and hope that with large number change can take place. If you don't take conspiracies serious, you truly don't have a grasp on reality. As crazy as it sounds, what you think to be true, when it comes to history and current events it's usually half the truth, which makes it a white lie people have come to agree upon. Truth is stranger then fiction. This is off topic, so lets get back to the facts of WTC and 9/11.

I am not insinuating anything.

The twin towers were not designed to withstand multiple hits from commercial jets. That is a gross exaggeration. They were designed to withstand the impact of a Boeing 707, which weighs around 80 tons, and was the largest airliner at the time.

The Boeing 747 model that did crash into the the towers has a take-off weight of a little over 400 tons. It is substantially more massive.

In neither case was the fuel taken into consideration. Quite simply, no one thought to, and frankly, even if they had, there would have been absolutely nothing they could have done about it.

Why didn't the fuel all burn up in the original explosion as the jet slammed into the tower?
I don't really know much about jet fuel, except that jets carry alot of it. I figured it just all blew up simultaneously.

I thought the planes that flew into the towers were a 767-200?

747(Maximum Takeoff Weight 910,000 lb)
Maximum Fuel Capacity 63,705 U.S. gal (241,140 L)

767(Maximum Fuel Capacity 23,980 U.S. gal)
Maximum Takeoff Weight 395,000 lb (179,170 kg)

707(Maximum Takeoff: 333,600 lb (151,315 kg)


It seems like the 767 isn't much heavier than the 707....no where near the 747

My guess is that nearly all of it would have vaporized and exploded on impact; with the wings rupturing as they did, it isn't feasible to have them leak slowly...

I do not see much if any fuel surviving very long at all...

I agree, there's also the footage of the lady standing on the edge of where the plane hit. If the jet fuel hadn't of burnt up completly on impact and supposively leaked all over, I doubt she would of been alive. I also read that if it was that hot, the windows would of melted.

It doesn't work quite that way. Jet fuel, which is a form of highly refined diesel, is normally pretty stable stuff. Just like in a truck, it explodes best as a mixture of fuel and air. In the case of the towers, the fuel went into the tower like a bucket. The great majority of it was in one big mass, and it drained down the gaping hole of the elevator shaft fairly quickly, the remaining vaporized fuel exploded into the conflagration we see on the video tapes. That fuel burned itself out within about fifteen minutes, but that was more than enough time to ignite every other flammable thing on the floor. It is similar to pouring lighter fluid into a charcoal grill. The lighter fluid burns up pretty quickly, but it burns long enough to ignite the charcoal, which burns much longer.



You are, of course, correct. My apologies, I was reading the wrong line off the specs sheet. The 767 that flew into the towers was less massive, however it was more structurally significant, in that where the 747 was essentially a converted plane from cargo to passengers, the 767 had a core designed for passengers, meaning that, in terms of impact, it was similar to a can striking a surface and the same can compresed to a lance striking a surface. I admit the details or commercial aircraft aren't my strong suit, however I am fairly certain that, regardless of it being 747's or 767's, the WTC were not designed to handle multiple impacts of each.

Not true.

http://www.freepressinternational.com/wtc_...ager_88888.html

What isn't true? Please don't link and fly.

The WTC towers were designed to handle the impact of a Boeing 707. They were not built to withstand multiple impacts from aircraft that had not yet been invented. And they were not designed to survive a fire created by 20,000 gallons of jet fuel being ignited over the entire floor all at once.

all that is known is that a skyscraper has never collapsed due to fire and the wtc had the largest steel columns ever used in construction-- building 7,the fact that the pentagon was struck 38 minutes into a terrorist attack and the symbolism of bush's action in acting out the goat story play are "all" hard core smoking guns-- forget about the ones that are not obvious like a terrorist failing to strike indian point not once but twice or wargames taking place that involved hijacked commercial jetliners being flown into the wtc the very day it actually happens,guilliani(ex prosecutor) getting rid of evidence,molten steel eight weeks later,murray treet engine,w199i,northwoods,ect,ect...

how did you draw that conclusion when the architect "minoru yamasaki" is quoted in the book by Angus Kress Gillespie :"Twin Towers: The Life of New York City's World Trade Center" as saying that the buildings could "easily" widthstand "multiple impacts" and equates the scenario to throwing a pencil at a screen door? not only that but the construction manager albert dimartini further stressed the integrity of the towers columns and made the same quote about multiple impacts so im having a hard time figuring out exactly "how" you reached this conclusion

LOL

I'de like to know how often Bush visits primary schools and helps with the kids reading skills.(It seems like a great photo opp,such a caring man )
I'de also like to know how all 3 towers fell almost identically when hit at different angles with different amounts of fuel burning up inside and outside the buildings.(or not hit at all in the case of building 7?)
Were the towers designed to fall in a neat and tidy pancake style?because it seems too clean imo,just like a demolition.

Hitting a nuclear plant would not be as devastating as you might think.
http://www.911myths.com/html/911_nuclear_target.html

There is some disagreement about the extent of the war games
http://www.911myths.com/html/war_games.html

There is only one source for this molten steel and no pictures. The only picture that is close shows something that is red hot hot but clearly not molten.
http://www.911myths.com/html/wtc_molten_steel.html

The fifth post down here
http://www.letsroll911.org/ipw-web/bulleti...6426&highlight=
makes a very good case that there is nothing unusual about the Murray St. engine.

I'm willing to be corrected about these if you have some info not covered in the links.

I would have to disagree on this point. My understanding is that jet fuel (jet A)is actually a refined kerosene, not diesel. As the plane was traveling several hundred miles per hour on impact and nearly all of the fuel was contained in rubber bladder built into the wings(which would have been torn apart by the impact to the building and steel supports, as can be seen by the huge amount of fire coming out the backside of the building); those rupturing bladders would have vaporized the jet fuel a great deal leading to perfect conditions for ignition. The huge impact, destruction of the plane and ignition of the huge amount of fuel that was seen leads me to think it is highly unlikely that another amount of fuel would somehow escape from the same fate...

Although kerosene is relatively stable, we use it in the fire department to begin fires when we are training and it does light up easily, and with the slights bit of vaporization will burn hot and fast. Drops of kerosene splashing on the ground from the tip of the drip torch we use flare and burn quickly. I can only imagine what they would do at 300 miles per hour.

**Sigh**

So much for asking one question at a time.



True, but as I said before, you will be hard pressed to find any skyscraper that has collapsed due to anything, fire or otherwise. Steel-framed buildings collapse due to fire, and there is really no way around that. And, again as I already said, that no skyscraper has ever fallen due to fire does not mean that it cannot happen; it merely means that we know how to do it right. There are scads of tables and manuels that dictate exactly what the fire resistant limits are for any given steel frame member, which means that they do fail, and we know exactly why and when that happens.



Completely irrelevant. We are not talking about conspiracies and agendas. We are talking about the physical aspects of the collapse.

Stop trying to de-rail the topic.



I would say it is because when we studied the WTC in college, we learned that Leslie E. Robertson, the chief engineer of the World Trade Center, stated that he designed the towers to withstand the impact from a Boeing 707, which was the largest airliner at the time. I suppose it comes down to a matter of preference; you choose to believe Yamasaki, I choose to believe the guy who built the towers.

And, once again, I have never claimed that the impact was the sole cause of the collapse of the WTC. It was merely one aspect.



That's it? That's your response? That is the culmination of your entire thought on the matter?

The purpose of this thread is for the discussion of the technical aspects of the collapse. If you do not agree, I would ask you to simply say so. Please do not get in my face and bark out a derisive LOL.



Not often, I hope. The man is the president of the United States. Photo opps are all well and good, but the man has a job to do.



Generally speaking, they two towers fell identically (i.e. down) because they were both struck in the same manner and underwent near identical scenarios. WTC7 did not fall in the same way that the towers fell, and cannot be called identical.



High-rises aren't really designed to fall. They all do fall, or would fall, in this manner though, due to the way they are constructed. I am assuming that you are wondering why they didn't just topple over? I can aswers that for you, if you wish.



That is entirely possible. I was always told in the military that the JP9 we used in our jets and that the boats tried to burn everytime they could for their diesel engines was refined from diesel. It is entirely possible that this idea came from the engines burning the fuel (the diesel generators), rather than the actual make-up of the fuel itself.

Regardless of whether or not it is refined from kerosene or from diesel, however, the argument remains unchanged. If you throw a match into a bucket of diesel, or kerosene, or even jet fuel (and this one I have actually seen done, to my shock), it will not ignite. If you have 15,000 gallons of the stuff flooding a floor, the fuel that will ignite is the fuel that is on the surface and the fuel that is splashed around. The vast majority of it, as one big wave, is not going to explode all at once.



I disagree with this. The rupturing bladders and the subsequent explosion would most certainly instantly vaporized a great quantity of the fuel instantaneously, but nothing like 15,000 gallons (incidentally, I'm pretty much pulling this number out of thin air. I'm assuming that, out of the 20,000 some odd gallons in the craft at takeoff, there was something around this amount left).

If you wan't to think about it in terms of quantity, the average pool has, what, about 10,000 gallons in it? In order to explode, there has to be a pretty good mix of air in that fuel; it can't all be just sitting there in one big lump. In an explosion, a great majority of the surface is going to be vaporized (even more, when you think about all the movement in an airplane crash), but the entire pool is not going to suddenly turn into a huge explosive cloud (how large would such a cloud be, a cloud made up of a mixture of air and fuel? Far larger than the impact sight, easily).

And, I want to point out, that regardless of the quantity, as long as we can agree that there was more than enough fuel to set everything on the floor ablaze within fifteen minutes, the argument remains unchanged. It wasn't the immense quantity of the fuel that brought down the towers. It was that there was enough of it to do what it did that matters.



Yes, but let's not forget that the kerosene you are using is neither highly refined, nor does it have the very high flash point that jet fuel does.

And again, as long as we can agree that the jet fuel in the crash was able to burn for long enough to catch things on fire, the argument still stands.
**********************************************************************

Now a note to Sunofone and dnb420,

You have, several times now, approached this thread antagonisticaly and derisively. Stop it. I do not know how you go about your day, but I sincerely doubt that it involves banging your fist on tables to make your point, laughing in peoples faces when you disagree with them, or belittling other peoples opinions. If you disagree with any of my opinions, then I would ask you to act like gentlemen and restrict yourself to a simple "I disagree," and maybe an explantion of why. I am not asking you to trust me. I am not asking you to trust our government. Hell, I not even asking you to believe anything I say. I am asking for nothing more than manners.

If this topic is so close to your heart that you cannot have a reasoned and analytical discussion about it, just as Fluffybunny does; if you cannot present arguments or counterpoints without making such claims concerning hidden motives behind 'despotic threads', or snidely commenting on how much a genius the guy answering questions must be, then do not post. There are plenty of threads where you can thump your chest and tear your shirt in your enthusiastic fervor.

In here, please mind your manners.

Nor afterwards. Only 3 buildings have done this and they were all on the same day.

This is a great posting since the poster is trying to explain the collapses through technical details, but I know this will eventually end up with a conspiracy theory or two thrown in. I'm not saying you should or shouldn't believe them, but just listen. I like to label myself a skeptical believer since I always question things before committing myself to something and then spend the rest of my time trying to prove what I believe to be the truth and everyone else is wrong since I may be wrong and someone else might be right or we might all be wrong and will never know the truth.

I had a question for the poster though. You said that building 7 didn't fully collapse? Can you post a pic or link to that picture? All the pics I've seen show a fully collapsed building with almost a perfect footprint were it was. Also in controlled demolitions if you watch videos you will see the trademark signs in building 7. Center is blown with the surrounding walls dropping in on itself which from the outside looks like the building is "falling straight down". Can you tell me of another building anytime in history (except for 09/11/2001) where a building has sustained structural damage (I'm not even limiting you to fire) that demonstrated this behavior without the use of high explosives? Thanks for your time.

That is true, but what must also be added when one says "No skyscraper has fallen before 9/11." is that "No commercial airliner with a full load of fuel has ever been deliberatly flown into a skyscraper before.". If one has a unique cause, then there should be no surprise at coming out with a unique effect.



Sigh. The eternal battle. I really have no problem if people want to discuss these theories; I just don't want them to discuss them here. It isn't like there is a dearth of threads to talk about them in.



I'll try and find the pictures for you. The building did fully collapse, eventually, but originally, the roof collapse in on itself from the fire, followed by a partial collapse of the front side of the building, followed, about half an hour later, with a collapse of the remaining side.



I honestly don't think I can. There might well be an example of a building having its entire support structure compromised all at once, but I cannot think of any off-hand. Buildings are designed with so many redundancies, so may fail-safes, so many ways to keep it from falling, that in order to consider it possible for them to fall, you literally have to think in terms of crashing airliners into buildings in order for the possibility to even manifest itself.

See, what you are seeing in the video as trademark signs of demolition, I see as the exact opposite. For starters, a building "falling straight down" is no more a trademark of demolition than it is of anything else. Buildings fall straight down simply because they are too heavy to fall in any other way. An excellent example of this is WTC7. It did not fall simultaneously, it did not fall all as one unit, and yet, it nonetheless feel straight down in a neat footprint. Any building that falls, regardless of whatever reason is going to fall in this manner. Buildings do not simply topple over; they are not designed to withstand the sorts of structural forces that leaning over would generate.

Another sign of non-demolition is the puff right before the collapse. A lot of people claim that this is the smoking gun of explosives, but demolitions do not work that way. If you look at the videos of demolitions, the only time you will see external explosions is when the support structure is external. On top of that, the "explosions" you will see are little more than sudden, muffled bangs. The reason for this is simple; demolition people do not want the explosive power of their charges to shoot debris out of the building into innocent bystanders. They want the power to go straight into the beam it is destroying, and they want as little power to spare as possible; if it only takes one stick and one charge to cut through a beam, you do not wrap twenty sticks around it.

Which brings us to another point about explosives in demolitions; they aren't that powerful. In order to cut a beam, a demolition team will affix a shaped charge designed for the beam, which will surgically cut through the steel like a knife. The reason it is called a shaped charge is because it is specifically shaped to guide the force exactly where it is needed, in this case, into a sheet of metal that will be jetted at speeds so high that it literally cuts through the beam like a knife through butter. That is only step one, through. Now that the beam has been cut in two places by the shaped charge (at the top and the bottom), a dynamite charge is exploded on the side of the cut segment, to 'kick' it away from the beam, in order to prevent snag ups. This charge is often 'tamped', that is, wrapped up with muffling material, so that the entire explosion is limited to the beam. You don't want random 1000 pound beam segments flying out willy-nilly; you just want them kicked out of the way, preferably only by a few feet. In other words, the huge cloud one sees in the video is not a sign of a demolition; demolitions simply do not work that way. You can see all sorts of debris being jetted away from the building; that is the result of an explosion, not an implosion.

It don't want to make this too long, so if you have any points you would like me to clarify, I would be more than happy to.