EBTX' mechanical analysis
The actual intent of those who brought down the towers was to prolong the collapse event till the TV audience was large and enough time passed for multiple individual dramas to take place, i.e. to involve the nation in the dramatis. They didn't want a Lusitania where the ship sinks fast (in minutes) ... but rather a Titanic scenario that takes a couple hours (or close to it). The audience can then imagine themselves involved at the building site ... trying to live ... but eventually dying having tried everything they can think of ... and ... failing. They wish for the country to "feel failure". Impotence (or imagined impotence) is much easier to control.
Approach of Planes
Approach of the planes
The angle of approach the two planes took to get at the towers is telling. Both hit a flat face in a line nearly perpendicular to the face they entered. The second plane was in the process of banking in a last bid attempt to hit the face flush and to avoid a dreaded corner hit. A corner hit quite probably would have brought down the tower immediately (as we shall presently see). And that's the last thing the bad guys want ... this is primarily a psychological attack ... the victims are the TV audience ... the people in the towers are merely tools to the end of attacking the audience psychologically ... this is an attack on the psyche, not the body. The bodies are simply "expendable".
Notice above that as you approach the towers, the approach angles that are acceptable are fewer than those angles that are unacceptable. Above all, we do not wish to take out the corners ... because ... the side beams of the towers are incredibly weak to an impinging aircraft.
Mr. DiMartini (who was killed in the collapse), stated that the towers could conceivably take "multiple hits" from airplanes. In some limited circumstances, perhaps they could. But as a general rule, the towers couldn't even take one hit. He was doing a PR job for the tower to ease the fear of potential crash disaster. If you've ever seen New York City from across the river, you know that the Empire State building and the World Trade Center towers stood above the other skyscrapers like giants among midgets. They were obviously targets and any potential renter would be uneasy about this. DiMartini compared the hypothetical crash of an airline into the tower to a pencil penetrating a screen door. However, unless he was terribly misinformed, that supposed "screen" took the plane not as a pencil but rather as a "plane" ... a long thing sliced into the tower like a knife through paper. Notice that the entire plane entered the building ... even the wing tips.
Imagine you're making a movie about a plane whose wing encounters a single steel beam sticking out of the ground. Wouldn't you have your CG people show the wing being sliced off? Or would you show the wing slicing through the steel beam like a knife through butter? Well, if the beam is stronger than the wing (a wing which is strong enough to deflect a goose in flight but not designed to withstand a multi-ton steel beam) ... it ought not to have penetrated the building. It should have been sheared off the fuselage and that fuselage should have entered the building (like a pencil) and the wings should have fallen to the pavement below or been sliced apart and gone through the interstices of the beams without shearing them. This didn't happen. What was the cause?
The beams had no strength against a lateral force.
But, you say, the lateral force of the wind was easily withstood up to and including a hurricane force wing of 140 miles an hour or more. Well, that sort of force is evenly distributed over the face of the building. The building would have some of its weight shifted to the lee side of the building (compression of the lee side). It would then have a restoring force to lean back in the other direction against the wind and no wind caused by nature could conceivably actually "lift" the windward side of the building. It can only take some weight off the windward side. All tall buildings are designed to have great strength in regard to compression. They have little strength against a lateral force directed at a point. And they have almost no strength against tension, i.e. if you tried to pick up the building by lifting the top floor, the rest of the building would simply tear away. It would never lift up the whole building. Why would any architect design tensional strength into a building ... tensional strength is for bridges ... right?
Well, not really. The design of the WTC was susceptible to cantilevered collapse. Because the design took out many beams to leave an open floor space, if you lose the outside beams ... particularly the corners because of their distance from the core ... the remaining weight is cantilevered on the cantilever pivot line inside the core assembly ... and ... the core beams to the front of the pivot line have a leveraged force applied to them far in excess of what they would bare if there had been intermediate beams between the outer wall and inner core beams.
In the above illustration, the intact side of the building at "A" has its weight reduced because the weight on the broken side, "B" is pulling down and forcing all the weight above the break to go to the pivot line of the cantilever. The still intact beams on the B side keep the whole top from rolling over but have a leveraged force on them. So, in fact, all the weight of the floors above the break come to bear on only those beams on the pivot line and the intact beams on the B side. All the beams on the A side may no longer take much weight depending on how much is taken by the still intact beams on the B side.
Now, if the corner beam is still intact, it has the best leverage to keep the top from keeling over. Cut a remaining corner after a side is breached in a big way ... and the building will come tumbling down. And this is what apparently happened. The bad guys let the structure burn till many people were watching on TV. Then they activated the thermate cutters at the corners and the top keels over. As it does, all the weight of the floors above the breach focus on the pivot line alone and it does not have the strength to hold the weight of everything above ... so ... before the top can topple over completely ... the whole building begins to fall down upon itself. Once it gets going, it's unstoppable.
The demolition detonations below the initial breach are for purposes of an orderly collapse. They didn't want anything sticking up at the end of the dramatis. That would imply "hopefulness". They want the viewer to experience total helplessness. No survivors ... at all. No building remnants ... nothing.
Why the external beams were weak
At left is the outer beam connection. Plates "C" are welded onto the beams and when the new section is attached to the structure, bolts "B" are used to connect both beam sections so that a continuous beam goes all the way up the side of the building.
The inspection holes "A" are a disaster waiting to happen. I was taken aback when I saw this engineering faux pas. You just don't put holes in your structural beams ... ever. The reason is clear. The hole weakens the beam at that point. What's the point of having four sides of steel everywhere else but only three and a half sides at the hole postion. Clearly, this is a weak link. But they need the holes to put the bolts in and tighten them.
What are the bolts for? These are not structural bolts ... they are construction bolts. That is, they are there to secure the beam to the structure to facilitate the addition of yet another beam section. They have some structural integrity because they keep the beam from sliding off the one below it. However, when something like an airplane hits them, the beams first bend inward and the bolts have their threads stripped out (their weakest connection). They are strong from a perfectly lateral force but pull apart when they get bent and are then receiving a vertical force relative to their threads (as evidenced by the forensic pics). And this is one of the main reasons that the beams gave way to the wing tips.
The other weakness of the outer beams (and to some extent the core beams) is the "coke can" defect. If you drain a coke and then have somebody stand on the can (on one foot, just the ball of the foot) ... then ... bend down and flick the can with your fingernail ... the can collapses. The key ingredient is high pressure on the walls of the can. This is the case with the external beams (also the core beams). The plane hitting the beam is the fingernail flicking the can. It collapses to flat (simple parallelogram collapse) and the wing can now slice it more easily. As it bends, the beam warms and the sweptback-wing of the jet slides by ... in a slicing action.
If the beams were better constructed, this would not have happened as I show in the design at right. Here I've arranged to put an internal triangle beam to reinforce the external triangle. This wouldn't be necessary if the beam were thicker but allows for a longer cutting edge using the same amount of steel. The cutting edge is to slice the plane apart rather than having the beam cut. I've bolted the beam as before but from the outside edge of the connector plate and I've welded them to one another as well as to the bottom of the beam (the top triangle should be slightly smaller than the bottom plate to accommodate the weld bead). There are no "access holes" to weaken the beams. The access holes were in the original design to facilitate an aesthetic, i.e. straight beams all the way up. Mine have a flange on them and so necessitate a different aesthetic. But for me form must follow function (I see the bolts and welds as more beautiful than any aluminum cover). Not so in the original tower ... form was paramount at the expense of structural (functional) integrity. :o(
If you are going to advertise your building as "plane resistant", you must show a formal static defense against such an attack. So here's mine. I don't just "say" ... I show.
Here's what I mean. The cutter beams are lined up to defend the corners. There are heavy cutter beams at least one fuselage width apart because if one is struck by the fuselage, it won't withstand a direct hit. So, we lose one heavy beam while the two on either side cut off the wings or split the jet engines in half. The smaller beams are configured as cutters but will take less to break. In any case, the lighter beams would have about as much metal as the WTC beams had ... just in a more robust geometry. In the central core we have much the same. The corners are protected by a pointed defense. If I were to say that my building could take a jet crash and still stand you could bet your life on it and see the why of it for yourself. Looks like a freakin' cactus, eh?
Core construction at WTC
I have yet to see a picture of the core joints anywhere on the net. If you know of one where I can see how the joints were made, let me know. For now, I can only make assumptions and redesign a new configuration of my own. I have some clues. They say that it was very convenient that the towers fell in neat 30 foot pieces ready to be trucked away. Of course, that's how they were delivered too ... in neat sections. Since they obviously weren't welded together by any robust means (as demonstrated by the few pictures of their ends), I can figure out basically how they must have been put together ... and I don't like what I came up with. I may be mistaken but ...
There are three parameters to building very large structures ... they are:
The woodpile effect is the construction method of the great pyramids and stonehenge. You just pile up stone and it stays put because it would take a great deal of force to dislodge them. I find that the World Trade Center buildings were primarily of the "woodpile" variety though they had aspects of triangles and some uni-body.
Engineers have employed triangles in construction ever since a caveman named "Og" discovered that after one side of his hut collapsed, the remainder was more stable (though it slanted to the rear and had less space before his head hit the ceiling). So Og employed triangles in his subsequent structures. It is easy to see that the triangle's sides are geometrically "fixed" whereas a square can collapse through a series or ever more eccentric parallelograms till it collapses into a simple line. So, whenever you are desirous of having something NOT fall over ... you put plenty of triangles into the design. The WTC had some "triangulation" in the design of the exterior wall but little in the core.
Uni-body construction was not invented by an automaker but they certainly capitalized on the words. In this parameter, all the components of a structure are held together by structural welds. Only some of the welds in the exterior wall were structural. Those in the core were purely "construction welds". The difference between a structural weld and a construction weld is that the weld bead must approach the thickness of the object piece. If that bead is much smaller than the width of the object piece, that weld is more of a construction weld and merely serves to hold the structure together till more pieces are added. It's kind of like putting a tree house together with duct tape when you should use nails. The exterior wall of the WTC had uni-body construction but the core did not. It was essentially just a woodpile that would have collapsed on its own in a wind as a free standing object. It relied on the external wall for lateral strength but had great compressional strength as a true woodpile should.
Why the core wasn't Uni-body
Wasn't the core completely welded together? Yes ... but ... there are structural welds and there are construction welds. To be unibody would require structural welds, i.e. weld beads on a scale of the thickness of the beam or deep thermite welds. At the base, the steel was 4" thick so you'd need a 4" bead to be a structural weld or use thermite to weld the pieces together as a single 1300 foot tall beam.
I believe, based on what little I've been able to so far uncover, that the beams were simply stacked on top of one another and a girdle of cross beams were welded to encase the beam ends so they couldn't slip off one another. If so, this is not structurally acceptable to me. It's the "cheap".
But cheap is consistent with this building in many ways. I see no diagonal cross beams in the entire mid-section of the tower where the planes hit. There are diagonal braces in the low floors and at the top but not elsewhere. (I may be mistaken on this ... not sure. But the absence of such beams is consistent with the rest of the architecture.
For my part, I would have put the main core beams together by the tried and true peg and flange method ... and ... I would have deep welded the core beams together with thermite. Now, not being in the building trades, I can't vouch for the thermite welding technique for tall buildings but it is used in other areas. To do this you'd machine a trench in the top of one beam and set the other on top ... then ignite the thermite and ... voila! ... you're smokin' cigarettes. Then you have a continuous beam the couldn't come down in convenient 30' sections in principle. They'd have to come down in multiple lengths all curled up and a real nightmare pretzel.
If a thermite weld is impossible or just not done in the tall building business, I would at least completely weld as best I could a peg and flange. In the picture, you see the peg prevents the beams from slipping off one another and is as strong as the beam itself. The purpose of the flange is to bear structural forces in case of airplane hit or an earthquake of magnificent proportions. The flange is as thick as the beam and so can carry proportional loads. Just welding things to the side of the 4" beams is like using duct tape when nails are required. It just won't do except to hold the pieces in place while you put up more. Mind you, the entire core is held up by the woodpile effect not these puny welds. If you just had the core standing free, a good "nor-easter" would knock it over. I would have designed it with the triangular cutter beams and peg & flange with deep welds if possible. This would, of course, add to the cost of the building ... but I don't go by cost ... just by what's prudent given the height of the buildings and the accepted possibility of a plane crash.
I would have further worked on the exact designs for the beams and made them into a three dimensional puzzle that would lock into place with the last beam ... now, that would be a challenge ... construct a building with no welds necessary ... all forces applied against one another so that the only way to deconstruct it is to take out the "key" at the top of the building then reverse construct. As far as I know there is no such building but it's undoubtedly feasible ... for a price.
The thickness of the flange would have supported a far greater vertical force than simple "ganged construction welds". Clearly, if the welds gave way, the mass falling from above would rip any welds below on the next lower floor as they slammed into them. The "flange" would have been as thick as the beam thickness at that level. Crossing form one level to the next should have been diagonal bracing welded to the top of the flange so as to take advantage of its strength. Ample diagonal bracing on every level would have given the central core a uni-body construction when deep welded and it would have had a "stand-alone" capacity. The real WTC core had no such capacity. It would have fallen with little lateral force. It remained intact only in the environment of the uni-body construction and heavily diagonally braced ... outer wall.
In the WTC towers, the outer wall had two out of the three structural parameters aced (diagonal bracing and uni-body construction). The third parameter (the woodpile effect) was in the core which had little of the other two. Together, the towers stood ... divided they fell ... just like Abe said they would.
Thus, the towers were constructed "on the cheap" ... using the least material to get the job done. When that minimal construct was stressed ... they fell. And, yes ... they were stressed by thermite and explosives ... but we'll get to that. The point here is that the structure was a weak design an not a robust one. Care had to be taken to get them to fall when desired, i.e. after the full audience had formed up to watch.
Now, what about that concrete?
They say there's hardly any concrete left in the pile after collapse. Hardly any means to me ... what? ... 80% or higher? Well, the concrete didn't just disappear. Some of it went airborne at the time of collapse. The rest was "powderized" and was all over the pile like a blanket of dirt.
What could have caused this?
If you drop a block of concrete from the top of the Empire State building that's say, 4"x 12"x12" ... what will happen? Right! It will break. Will it powderize? Hell no. You'll be left with some big chunks. So why did the concrete in the WTC powderize? Simple ... It was NOT due to explosives ... they couldn't do that either. So why?
Clearly, we have to look, not at the forces involved (considerable as they were), but at the concrete itself. Is this driveway concrete ... no. Is this highway concrete ... no. Then what is it?
It's mob concrete. Or, as they say in the construction trade ... "light concrete". This is concrete that isn't bearing much weight and so doesn't have to have as much strength ... mob concrete is "super-light, light concrete". In fact, you can float it to the site with zoo balloons ;o)
This is the type of concrete you get when you put up a building in Manhattan. They control construction. They get the contracts. And what do you get? ... the shaft of course. It's what they do. It's their "ethic". A mobster must do these things to feel he's doing his job (fulfilling his ethic). It's the source of his self-esteem.
To make mob concrete, you get sand from the beach on Long Island (maybe you take out the sticks, maybe not) ... then ... you put in some Portland cement to hold it together but you use the least amount of Portland cement necessary 'cause that constitutes the biggest ripoff as is required of the mob ethic. The people pouring the concrete notice ... but they say nothing because they know that it's not structural concrete and it will just have carpet laid over it ... nobody will die because of it. When Mr. Serpico-concrete-pourer says he's going to the newspapers he is told by "Vinny" ... "I'm sorry about yo wife gettin' raped in duh supermahket pahkin' lot last night". Serpico says, "My wife didn't get raped last night" ... den Vinny says, "Oh, sorry, I mustuh been thinkin' about some udduh guy's wife. Dere's a lotta dat goin' round yooz knows". Then Mr. Serpico says, "Oh yeah. I guess I was wrong about that concrete too. Anybody can make a mistake.". And that's how it goes with mob concrete.
The shock of collapse and possible explosions was enough to break the chemical bonds in the concrete and turn it back into sand with Portland cement to make it gray. This is what must have happened to the concrete. I see no other alternative in this universe ;o)
Explosions in basement of Tower
Eyewitnesses report huge explosions in the basement areas strong enough to knock down walls, blow out doors and kill people. William Rodriguez asserts that the first big explosion occurred in the basement before the impact of the plane on the upper floors !? These mystery explosions are difficult to assign to the initial impact for physical reasons as well.
Look at the problems you get here. If gas drops to through the elevator like rain ... it would take as much as 14 seconds to get to the basement (~10 seconds free fall and a few seconds added for air resistance). So, unless the jet fuel is driven to the basement faster than freefall, you can't have a firey expolsion down there. Maybe a rush of compressed air ... but no fire. Yet people are said to have been burned in that lower explosion.
At impact the jet is going around 500 mph ... so was the fuel. But redirecting that velocity so that the fuel screams down the elevator shaft is laughably inadequate. What happened to the fuel is that it vaporized on impact, spreading outward in the general direction of the impact ... then, ignition by sparks all over ... and voila! ... explosion and rapid expansion of the fireball. Note that the expansion of the fireball occurs at less than 500 mph (a good deal less as it enlarges till expansion ceases). The fireball attains a maximum size comparable to the width of the building (about 200 feet).
Now, being that the floor impacted was around 1000 feet up, we can reasonable expect that the fireball made it into the busted open elevator shaft and rushed downward in a manner and similar speed to the rest of the explosion. Maybe it went even further down the shaft, but does anyone think that the initial fireball would travel down the shaft all the way to the basement while the blast we saw on TV was only 200 feet in diameter?
In favor of descending down the shaft we have that the volume of air displaced in the shaft increases linearly with distance rather than as the cube of distance traveled as is the case with an open air burst, i.e. the shaft has straight walls while open air is a ball getting larger so if the ball is twice as big it occupies eight times the volume but the shaft which gets twice distanced is only twice the volume.
But against this expansion scenario we have that the shaft is constricted by elevator doors and friction with the sides of the walls whereas an expansion into open air is unrestricted except by the inertia of the surrounding air.
Would the blast travel down the shaft eight times as far as the initial 100 foot blast radius? I have to assume that it would not go that far due to the restriction from the closed elevator doors, intervening elevator cars and friction with the walls. These factors coupled with the open air acting as a safety valve should cause the penetration of the initial blast to be less than the maximum of 800-1000 feet down an unrestricted (open) and friction free shaft. So, for the sake of my argument, I'll "guess" that the initial blast goes down the shaft 400 feet and stops there ... more than the air burst but less than maximum. Therefore, the greatest compression is probably no greater than about twice the normal air pressure of the shaft. Note here that "twice" the normal air pressure is about 29 pounds per square inch which is, indeed, a terrific overpressure.
Now, we can calculate. ;o)
The elevator shaft in the big elevator we are talking about (I was in it twice but can hardly remember) is maybe 6'x10'x1000'= 60,000 cubic feet. So, we're going to sling around 30,000 cubic feet of air here. The lower lobby is about 207x207x45= 1,928,205 cubic feet minus the volume of the core section at the lower lobby ... so ... 1,928,205 - 87x35x45 = about 1.8 million cubic feet.
1,800,000 + 30,000 cubic feet = 2,100,000 cubic feet of air in the same space of the lobby after it's all pushed out into the lobby (under generous ideal conditions).
So, we have on the elevator door ... about 14.7 pounds per square inch extra ... and
Our elevator door is approximately 6 feet by 7 feet if I remember correctly. Big, for lots of people to get in quickly (occupancy of these elevator cars was 55 people). So, the total pressure on the door is 42x 144x 14.7 = 88,905 pounds or about 44 tons applied gradually from 0 up to 44 tons over about two seconds.
This will indeed blow out the elevator door ... though I would expect them to remain attached to the frames ... just bent way open and ripped up. Having lifted 20 ton loads with a crane when working for Jones & Laughlin Steel, I sense that no elevator door made would stand up to twice that. Fire might follow a second or two later. Initially, it would be an air blast from the regular air in the shaft that blasted open the elevator.
In the lobby we have pressures on the lobby windows of ... 2.5 pounds per square inch. We know that the windows were thick enough to hold in hurricane force winds of maybe 140 miles per hour. That force of air on the windows would be about 50 pounds per square foot. Let's be liberal and give it 80 pounds per square foot. Now, we divide this by 144 inches per square foot and we get ... about 1/2 pound per square inch.
We get only a half pound of resistance in the windows (from a hurricane) but the air from the elevator shaft pumped into the lobby yielded two and a half pounds per square inch ... the windows will be blown out.
I initially rejected the idea of the upper jet fuel explosion causing the lobby damage ... but it is probably true and this part of the case is reasonably solved. However, some experiment built to scale might show a different outcome owing to the distance the blast traveled down the shaft. If the blast only goes 100 feet down, the entire outcome could be in doubt. So, I consider the matter only potentially solved and look to other indicators of "intrigue" which are more robust.
Note here that I do not rule out an explosion in the basement. Mr. Rodriguez states unequivocally and with neither change nor guile that a large explosion did occur there before the plane hit above. I tend to believe people of experience when voicing an opinion in the realm of their experience. And, an attempt to assist the towers in their fall is consistent with the days other events which are unquestionably indicative of conspiracy and totally consistent within the context of government criminal activity in past decades.
This is the true smoking gun of intentional demolition. By the rules of physics there should have been no molten steel anywhere at the site of the World Trade Center "piles". Not at WTC1 or WTC2 or WTC7 ... but there was molten steel there as attested to by many witnesses. There is video of yellow hot steel ... not aluminum but actual WTC beams ... right on the internet. Not only can there not be molten steel but neither can there be yellow hot steel. The temperature is too high for anything that happened there ... if it was all "kosher". I have been unable to find or imagine any process there on that day that would have heated steel to those temperatures.
I have seen a lame attempt by the professional debunkers to assign the molten steel to "It's actually aluminum" or "The steel is burning and pouring water on it made it burn more" both of which are laughable. The pics are obviously of yellow hot steel beams ... and ... steel burns, it's true, but not in the conditions of the trade center. The debunkers haven't been able to formulate any rationale for the appearance of molten steel and neither can I (other than an intrigue).
Let's examine the burning steel issue.
You take a piece of steel wool and touch a 9V battery to it. Voila! You're smokin' cigarettes. Unfortunately, you need to blow on it like a blast furnace in a vain attempt to keep it going. And yes, steel rusts and gives off heat. However, it has never been known to "spontaneously combust" when left in a big pile ... not even with smoldering debris interspersed. And adding water to make it rust faster and give off more heat ... sheesh. Water is one of the primary ingredients in rolling yellow-hot steel. You need to cool the rollers to keep them from deforming while pressing the hot steel. If they were going to combust with water we'd better inform the fire department not to use water in steel structure fires as they might set the entire neighborhood on fire.
The only possibility here, other than thermite (-ate) charges is electricity. Let's say there's an electrical feed to the WTC and it's not turned off for five friggin' weeks and it's coursing through the steel beams and into the ground ... yeah ... maybe there'd be some molten steel. Remember, they forgot to turn off the electric to the Towers 1,2 & 7 for 11 weeks when they found molten steel and some guy says ... "Hey, yooz guys, turn off duh 'lectric, my shooz is boinin' up". If you believe this ... we have shares in the Brooklyn Bridge to sell you. Electricity is one of the first things the fire department would have done, in concert with the DPU, immediately upon the tower collapses.
Hmmmm ... wait a minute ... on second thought it couldn't be electricity because ...
Electricity would be fed to the steel pile by a heavy copper wire ... and ... if the steel-copper connection were really good ... no melting would occur there. The melting would occur at the nearest fuse, up the line toward the power station, i.e. you'd blow a fuse somewhere (actually, trip a breaker). Now, if the steel-copper connection were tenuous, you could get an arc that would melt steel ... but, it would also melt the copper and when the connection burned up the line a bit, the current would cease. To get electricity to melt steel, you need a controlled connection as in an arc welder where the welding rod is held a fraction of an inch off the object piece. Then, electricity flows from the closest point on the rod to the closest point on the object piece, i.e. through a very skinny connection. A fat connection produces less heat than a skinny connection because resistance goes down with the fatter pipe. So, if you touch the welding rod to the object piece, the connection between them gets bigger, the resistance lowers, the heat goes down and the rod usually gets stuck to the piece and you have to struggle to free it. I know that from my little welding experience at the steel warehouse. Their instructions were, "Make little horseshoe shapes and don't touch the steel with the rod".
Because an electrical connection cannot be controlled continuously, even if the electricity were left on and no breaker tripped at a sub-station ... electrical melting is impossible.
Under certain circumstances it is conceivable for some of the steel in the wreckage to have melted after the buildings collapsed. Any molten steel in the wreckage was more likely due to the high temperature resulting from long exposure to combustion within the pile than to short exposure to fires or explosions while the buildings were standing. - N.I.S.T. (see #13)
Above is a quote from a NIST report. They admit the obvious that it couldn't have come during the fire. If melted steel was there ... (and they certainly know it was or they would have cowed the critics with a disclaimer stating that only "maybe" it was there) ... it must have melted due to more prolonged fire inside the pile ... "under certain circumstances" ... I would ask them to name one such circumstance.
If a fire was "on at point A" after the collapse ... what burned there? ... in one place (point A) ... long enough to melt steel (here I am assuminig that you have the most perfect insulation possible coupled with an antithetical perfect air flow to supply oxygen ... and a conveyor belt to bring more combustibles to point A ... and let's throw in a blast furnace effect to boot). Yes, the blast furnace effect blows oxygen right at the combustibles conveyed to point A where the steel is heated sufficiently to melt ... then that blast furnace air (focused, forced air) is then defocused so as to come out of the top of the pile everywhere so nobody notices there was a blast furnace effect somewhere down below.
You melt steel by design. It does not occur easily. That's why there was a copper age followed by a bronze age followed by an iron age. It took a long time to learn to melt iron by a combination of heavy air flow, lots of combustibles and insulation of the oven. The only natural example of melting iron for these people was the heat from a volcano and I don't think they had the expertise to harness that. They had to figure how to focus heat for prolonged periods to melt iron and they didn't get any accidental help. They "worked" the heat focusing problem for centuries till they got the temperature way, way up and could sustain it.
The primary problem with the molten steel is the second law of thermodynamics. Once the heat is released, it tends to go away. It flows out into space. Heat goes out ... it doesn't focus itself anywhere else again unless someone sets up some kind of lens or mirror to refocus the heat. Or, alternatively, if you could just trap heat for awhile ... and ... delay its departure with insulation ...while more heat was added ... you could get those high temperatures to melt steel. However, I know of no instance wherein this has occurred without human intervention, i.e. by design. As far as I know, steel has never accidentally melted anywhere on earth in all of recorded history. There's just the volcano example. In every other instance somebody set up and maintained the conditions required to melt that stuff (iron). Copper and aluminum and some other metals can get melted by mistake in a cooking fire ... but not iron. Iron needs conscious attention.
Some people assert that there is more than enough gravitational energy released to melt steel. True enough. Now focus it on a particular spot and let the melting commence. How is it to be focused? I can see hot to the touch, bent steel beams ... but that's it. They don't glow ... they're just real warm-to-hot.
This leaves thermite and its variants as the only presently available culprit.
The actual fall
Here, I'd like to develop a plausible scenario wherein the towers fall without assistance and in the manner seen by the audience. I wish to do an advocacy the official view to see if I can support it to reasonable effect.
First, can a building such as the WTC fall in a manner not like what we saw? That is, other than straight down? I submit that it cannot. Any building of this size must call roughly into it's own footprint. Here are the reasons.
No building whatsoever can topple over like a wood block for to do so would require that it raise its center of mass. Thus, the diagonal form the edge of the base to the center of mass is necessarily longer than the height of the building straight up the side to the level of the center of mass. Hence, the center of mass would have to go over its own height in order to be pushed over in this manner. What a mighty wallop it would have to absorb to do this and how strong would be its sides. Impossible in principle due to the tremendous mass of buildings.
To fall over, it must be undermined on one side. Then the center of mass can drop and the vertical center line can lean over like a yardstick falling. Right? Wrong also. While this may be true of small buildings of only several stories, a tall skyscraper cannot.
The strength of materials increases with the square of their cross section. But their mass increases with the cube of their size. So, if we double the size of a structure in every aspect, we increase the strength of the beams that support it by four times but the weight it supports increases eightfold. At some point of redoubling, the structure will just fall of its own weight. Hence, very big buildings are not simple extensions of little buildings. There are complications in the engineering.
These super tall buildings are designed to bear vertical weight. If they were upgraded to hold at a severe angle, the cost would be ridiculous and nothing would be gained for if the building were to hold solid at a 45o angle, what difference would that make to to outcome. It would still fall. Hence, when a big building just starts to fall over the structure just crumbles into its constituent pieces, i.e. all the welds start to break and the beams bend and down she goes. The beams won't support any significant weight at even a small angle of say 5o. As the collapse gains momentum, it transforms into an almost straight down path to the ground. This can be seen in the demolition of a tall smokestack. As it begins to collapse by falling over, it breaks apart in midair and the top piece gets only a small velocity away from the vertical and so lands close to the base.
Understand that all pieces of the building want to fall vertically at a rate of 32 feet per second squared. The can't because the other pieces are in the way. When they are substantially out of the way, sections break through one another, shearing off pieces because the vetical force is no longer parallel with the side of the building. Again, when a big building is at any small angle from the vertical, it just disintegrates because you can't economically build a structure to sustain the forces involved and it wouldn't do any good anyway. The building would still fall over killing everybody.
Now, we need to get our WTC to fall into just about its own footprint. We already see that it can't fall too far out ... certainly not more than half its height. To keep it in we need a "funnel effect".
And that's just what we have in the WTC design. When the floors give way, they fall vertical into a shell formed by the exterior wall. As the walls banana peel out from the center, the forces that send them out constitute a reaction force to propel the floor junk back into the sleeve formed by the perimeter wall. Get it? As the banana unpeels, the internal material goes down the hole.
The core is the problem. But these beams have no significant strength to resist a laterla force directed toward the center because they are constructed "on the cheap" ... remember? They have great strength for resisting compression but essentially they are just an example of the "woodpile effect". So, they fall in the hole too because when the floors are pushed back into the center by reaction with the outside walls, they run into the core laterally ... in a manner attacking the core at its weakness. This process continues all the way down to the ground.
The floors collapse and want to fall out away from the path of greatest resistance ... but they don't because they meet up with the outside wall which sends them back in toward the center by reaction while the outside wall is propelled outward in a banana peel collapse. The floor material hits the core beams with a lateral vector busting loose the cheap side and the core falls apart like the woodpile that it is. You need to get over the idea that the core is uni-body ... it's not. It's a woodpile with no substantial connection to itself or anything else. It only stands there if it can lean on the external wall. When that goes, any little force from the side will bring it down. But it's damn strong in the vertical.
Have I succeeded in convincing myself that this was the way it went down? Yes ... and no. We have major contributing factors here ... but not enough to get the government off the hook.
Airflow around the collapse
As the floors are pancaking, they squeeze the air out ... very fast ... so it's under great pressure. The air exits the floors through the exterior wall as it gets out of the way and through the core which is essentially a big donut hole. By percentage, the outside will get ... perimeter
207x4=828 [outer perimeter] ... divided by (137+67)x2=408 [inner perimeter] comes to 2.02
This means that 2/3 of the air on the floors will exit outward and 1/3 will exit through the core. And we see this happening. The air going out causes dust & debris to be blown outward. As it falls, it forms an air-dust-chunky composite that resists clean air flow through it. Consequently, it acts like a parachute and inflates outward. The air pressure under the parachute is greater than the surrounding air and this supports the parachute.
The remaining 1/3 of the air takes up dust & debris and goes toward the center line of the building where is collides with the other debris coming from the inside on the opposite side of the core. So, it just sits there with no net velocity and as the building goes down, it is left like a "smoke monument" for a moment in the shape of the core.
Here, I wish to deal with the fall rate in the context of conservation of linear momentum ... one of the cornerstones of physics. I have heard of physicists doing the calculations for this particular fall and getting as much as 40 seconds (as a minimum fall time) when including conservation of energy considerations. But that is a more difficult estimate because I don't know what weight each floor was designed to take and what distance to apply that force through ... to get an energy number. So I am sticking to linear momentum conservation alone which is the easier calculation because it is independent of the mass of the floors.
If there is a possible way to get around linear momentum, it certainly wouldn't occur in a common fall and collision. Understand here that there is no known instance of a violation of conservation of linear momentum in the entire earth's scientific experience. So, if one shows that linear momentum conservation is violated in the fall of the towers ... then ... they were brought down by demolition ... no ifs ands or buts.
The calculation is simple enough to be understood by anyone who has taken high school algebra and physics. I'm going to do it the long way (floor by floor) rather than shortening the problem into a single integral equation. Be patient.
Let's make the equations first
The distance an object falls in the earth's gravitational field at the surface (ingnoring air friction which slows the fall) is ...
Where "a" is the acceleration due to gravity and is 32 feet per second per second ... 1/2 a = ~16
The velocity an object achieves after falling a distance (D) is simply ...
And, the time of the fall is ...
Let's check it out ...
The tower is 1360 feet tall, so the time of free fall ... if the tower's mass was all hovering at the 1360 foot level in one thin block and suddenly fell in a vacuum ... would be ...
the square root of 1360 divided by 4 = 9.2 seconds (this is the absolute minimum fall time for the towers if demolition charges were expertly placed and the building came down without any resistance whatsoever)
So, if something falls in 10 seconds even, it must have started its no-resistance fall at ...
16 times 102 = 1600 feet up in the air ... and so on for any other height.
Now consider a two-piece building
Here, half of the mass of the building is compressed into a flat piece at 1360 feet ... and the other half of the buildings mass is half the distance down in a similar flat piece. Let the top piece free-fall and slam into the other half at the 1/2 x 1360 = 680 foot level.
We can compute the velocity of the top piece when it hits the second piece. We need the time of fall first which is ...
6801/2 / 4 = 6.52 seconds
Then, the velocity is ...
6.52 x 32 = 208.64 feet per second (about 142 miles per hour)
Now, when the top piece hits the stationary piece at 208 feet per second it will be slowed and the stationary piece propelled down with it. They go now as one piece and the law of conservation of linear momentum requires that the new velocity be half that of the one piece by itself. Thus, we have one piece at 208 fps and another piece at 0 fps = two pieces pancaked together at 104 feet per second. Then we add to that velocity ... whatever additional velocity that as the now doubled mass will acquire by gravity through the remaining 680 feet to ground level.
In general, if we divide up the building into such equal pieces (floors) and let them "pancake" into one another progressively ... the slowing of velocity due to collisions of stationary floors with the "falling-as-one floors" ... will be inversely proportional to the mass increase. Thus, if 6 floors are falling as one and collide with yet another stationary floor, their mass will then increase by 7/6 and their velocity will be 6/7 of the collision velocity. If the increase of mass is 9/8, the decrease in velocity will be 8/9, and so on.
Linear momentum is then conserved since 6 masses with velocity "1" collide with 1 mass of velocity "0" and we end with 7 masses falling-as-one with a velocity of 6/7. Thus,
Adding up the velocities
We have to add the velocity acquired by acceleration due to gravity, to the initial velocity of a falling object. Thus, in addition to
agravity x ttime = vvelocity from continued acceleration
we have to add the "before collision velocity" in order to obtain the final velocity of collision. We do this by defining the distance between floors. Thus, if we make the distance between floors 680 feet as above we get ...
Which is a simple second order equation (quadratic).
0 = 16t2 + vit - 680
Now, we cheat and go to www.akiti.ca/Quad2Deg.html ... plunk in the coefficients and click on "Calculate the Solutions" and we get t (the time of fall from one level to another with both the new acceleration and the old initial velocity accounted for).
Here's a compressed screen shot of the web page to calculate from. Remember to make your distance between floors negative and that gives the physically appropriate solution.
Then we just do the same thing over and over and over for each floor ... then add up all the times between floors ... and that's the total time of collapse possible. Remember, this is absolute. There is no appeal to conspiracy or lack thereof. Nature doesn't care about us one way or another.
Now, let's do some examples
For one floor we already have 9.2 seconds.
For two floors we get this ...
Let's do it again for three floors ...
I did this for 4 floors then 5 floors then for ten floors and got total collapse times of ..
1 floors = 9.2 seconds 2 floors = 10.55 seconds 3 floors = 11.35 seconds 4 floors = 11.77 seconds 5 floors = 12.13 seconds ----- ----- ----- ----- 10 floors = 13.09 secondsSo you can see that the time of collapse gets longer as we divide up the mass of the building into more and more equally spaced floors of equal mass. Understand too that air resistance would make the fall take a tiny bit longer. Junk falling off the sides to free fall on its own would also slow the collapse because those masses would contribute to the slowing on impact but not to pushing the process forward through the other remaining floors. Also note that the amount of mass has no effect on the velocities because everything ... no matter what its mass is ... falls at the same rate in the earth's gravitational field (as per Galileo).
Basically, the problem is that no matter how you arrange things, the top floors have to accelerate the lower floors and in turn are slowed so that a pancake collapse necessarily takes awhile longer than just a straight free fall. If ten floors fall, they must accelerate the next ten floors from their initial stationary position. Given what I've done already, I think a collapse of 15 to 16 seconds for 100 floors could be expected. Note here that though the addition of more floors slows the process ... they slow the process at an ever decreasing rate. There's probably a limit in there someplace.
My conclusion is that the fall of the towers is inconsistent with the pancake model. The floors beneath the point of initial collapse must have given way prior to the arrival of the top floors, i.e. by explosive demolition. Understand that I haven't attempted to include resistance of the steel in the towers to the collapse which would have further retarded the progress of the fall. With that in place a fall of 20 or more seconds is not unreasonable. 11 seconds is definitely unreasonable.
That Pesky Beam
Here is a poor quality image of the beam that was originally seen as evidence of thermite sabotage. It has been downplayed by the debunkers as a cut made post-collapse by the demolition crew. This may be the case but ... forensically ... it appears to be more likely the work of "sappers". let's give it close scrutiny. To do this you will need to find the original pic on the web. I lost the url ... it should still be there somewhere. My pic is "double-jpegged" and detail is lost.
It's been cut with either thermite (if sabotage) or by a steel cutting torch (if by demolition crew). Which do you favor?
The cut appears to be at or more than 45o. When pressed about the 45o angle, the debunkers state that demolition workers often make cuts at an angle to take advantage of the heat which is carried by the molten runoff downward (gravity) and hence, it's easier to cut through the pre-heated steel than to go straight across which would seem to be the obvious path of least work. And this may be true ... for thin steel. It is not so for thick steel such as the beam shown.
Here the run off of molten steel is fairly insignificant in the pre-heating of the next steel to be cut because of the depth of the cut (about four inches). I contend that no one experienced in demolition would make such a cut but rather would go straight across, thus making the cut about 40% shorter. This would be easy to prove with a "blast off", i.e. a contest between two experienced cutters to see who could cut the beam faster ... straight across or diagonally at about 45o. Anyone want to take bets?
The cut appears to be very professional. It's very even. In demo work precision is not the foremost concern because you're destroying something that's already trashed. You just want to knock down the leftovers. However, demo work requires precision for the initial collapse event because you want the whole building to fall righteously straight down with no injuries to people or other structures. In this phase great care is taken and much planning and precision work is done. The cut looks to me like a precision cut beam of the first phase type.
Now, we can dig a little deeper into the forensic evidence that the original pic provides.
I've labeled the four sides A, B, C and D. What I wish to draw your attention to is the fact that all inside lines and all outside lines like Ci and Co appear to be coplanar with the exception of Bi, the inside line here appears to be below the plane of the rest of the lines and parallel to it.
To achieve these results the cutter must have been in these positions:
Though this situation is not impossible ... it is also consistent with cutting the beams with thermate with the drill and pack method.
In this method, you drill holes along the perimeter and pack them with thermate. When the thermate is ignited, it melts the walls between the holes and the beam is weakened or cut. All the holes are drilled such that they are in a downward line relative to the gravitational field. This keeps the molten metal from running out until it has done its job. These holes don't go all the way through the beam or the thermate would run out on the inside of the beam. You would want to keep the inside and outside lines in the same plane to facilitate blowing the beam section out with an explosive charge that's independent of the thermate cut. On face B, there is a little geometric problem with the requirement that the holes be drilled downwards. The line Bi would be below the plane of the other lines ... but the charge should blow out the section anyway if sufficiently large. At the corners of face B, there is a little problem too. Because the Bi, Bo plane is sloping away from the plane of the other lines, the anomalous corner (Q) remains there ... again, a sufficient charge should blow out this problem anyway.
Here's a diagram of the drill & pack method with separate propelling charge.
The Work Itself
Bringing down the Towers was a huge undertaking requiring at least a few years of preparatory work like computer physics simulations to design the right sequences and coordinate everything. My personal, off the cuff estimate is that I could do the manual labor myself in about 10,000 man-days, i.e. it would take me about 40 years work to set the charges and everything in one building. That means 40 years of 40 hour work weeks with time off for holidays and two weeks vacation each year ... no overtime ... please!
So, two guys could do it in 20 years and 10 could do it in 4 years. Two dozen could do it in maybe 20 months. That seems about right. A couple dozen motivated guys working regular work schedules (maybe night shift) for less than a couple years. They're making a couple million each for the job so for two towers that makes maybe $50,000,000 bucks ... and that's just for semi-skilled labor. Then there's the materials (much less money than the labor) ... maybe a couple mill extra. Throw in building #7 and the Pentagon and a tidy profit for the organizers and I think the entire operation of 911 could be done for around $100,000,000 bucks. A fair bargain considering the profits made in Iraq resulting from the consequences of 911. Whadya' think? Isn't that reasonable?
You don't want too many people involved as this might arouse suspicion. A couple dozen guys in work uniforms with names like Acme Computer Systems would allow them to freely mingle with the other workers. They'd probably make dates with secretaries and be on a first name basis with their future victims. They could pull wire for charges under the cover of "network upgrades" and install boxes of explosives at any juncture with the wires. The explosives would be in tin boxes marked "AC SYS sec.1482-b" with a flashing green LED light showing the the system was operational. Then they close up the ceiling tiles and install the next bomb. Nobody would question them and they'd be very affable and maybe make some complaints about their terrible working hours and things like "Sorry, we have to inconvenience you but ... it's gotta' be done by Tuesday or our boss gets socked with a $1000 a day over deadline charge.".
If you had 100 guys working for two months somebody might question what's going on more closely. But as the project grinds on month after month and nothing bad happens ... who's gonna' ask anything at all. Construction and maintenance go on round the clock anyway in such a large building as a WTC tower.
Nobody would question anything.
Except possibly security ... and these guys are in your pocket ... being of the same crowd as the "destructo team". Hey, there'd be a contest between Tower 1 and Tower 2 teams to see who could do the mostest ... fastest. Winner gets bonus days off and incentives. Maybe we should add another 50 mill to the cost of 911 just to accomodate these other variables.
Other Labor Stuff
Somebody complained that the amount of thermate needed to take down the towers and account for the molten metal at the bottom of the debris would be many tons. I agree and say, "Where you want it?". I mean, I wouldn't have any trouble at all transporting maybe a half ton of bags of ACME Cement to the 100th floor to the tower ... each and every day. It's easy. Get a two wheel dolly and make five trips up the elevator with 200 pounds each trip. Same goes for parts and any other stuff they'd need to do the job. If you've got months and months ... anything can be blown up.
I don't see any problems at all in setting up the destruction of the World Trade Center. It's a breeze ... if you're evil ... and ... you're gettin' paid well ... so ... you're proud of your work and ... have no conscious at all.