QUOTE(SiLeNT(U) @ Aug 19 2005, 11:52 PM)
I hate people who are so damn patriotic they can't see what's right in front of their eyes.
[right][snapback]293584[/snapback][/right]
Yea, I hate when everything that's infront of my eyes says that planes made the WTC fall down.
Since I'm clearly a patriotic idiot please tell me what's in front of my eyes.
And please, if you have information that says otherwise, post a damn link to it. Or some proof.
Because to me it is as if you are telling me "WE ARE LIVING IN A MATRIX, PERIOD" without any proof at all.
QUOTE
I read a tiny bit, then looked at the picture...
Now tell me... How could the WHOLE building collapse, when hit so high up...? Hmmm....?
Here's your answer:
QUOTE
One and Two World Trade Center
Schematic of 1 WTC with impact damage. Note narrow central shaft into which all internal columns are bunched. Adapted from NIST report "Baseline Structural Performance and Aircraft Impact Damage Analysis", October 19, 2004To meet the challenges of wind load, gravity load and other common architectural stresses, the WTC's structural engineers took a then unusual approach in its construction— instead of the typical high-rise infrastructure utilizing building-wide rows of heavy columns within walls, each tower was essentially a hollow steel tube staked to the earth by a cross-sectionally narrow array of columns running up the building core. As secondary supports, each tower had 240 thin steel columns sheathing the facade, a signature feature that allowed the number of internal columns to be very small for such huge structures. The result was super-tall, super-wide office buildings with maximized expanses of column-free floorspace.
After the aircraft impacts on September 11, 2001, it appeared to most observers from the ground that the buildings had been severely but not fatally damaged. They did not realize that intense heat from the burning jet fuel and combustibles, deposited near the cores of the towers by the two aircraft, was weakening the central steel columns, longspan floor trusses and the joins connecting the floorplates to the external columns. As is well known, the strength of steel drops markedly with prolonged exposure to fire, becoming more elastic the higher the temperature. Thus it could be said that the towers burned down, basically, or were destroyed by fire, and that any steel of any building would have degraded in the same way. This is something of a tautological argument, however, because the lightness and hollowness of the towers had much to do with the jet fuel (and resulting fire) reaching so far inside in the first place. This lightness and hollowness were functions, primarily, of the absence of building-wide rows of columns (and attendant walls), the absence of masonry elements or heavy steel in the facades, and the use of gypsum cladding rather than reinforced concrete to shield stairways and elevator shafts.
Impact locations for towers 1 and 2.
Impact locations for towers 1 and 2.The towers were each struck by hijacked Boeing 767 jet planes, American Airlines Flight 11 and United Airlines Flight 175. A typical Boeing 767 is 180 feet (55 m) long and has a wingspan of 156 feet (48 m), with a capacity of up to 24,000 US gallons (91,000 L) of jet fuel. The planes hit the towers at very high speeds: Flight 11 was traveling roughly 490 mph (790 km/h) when it crashed into the north tower, Flight 175 hit the south tower at about 590 mph (950 km/h). The resulting explosions ignited thousands of gallons of the jet fuel and immediately spread the fire to several different floors simultaneously in each tower, consuming paper, furniture, carpeting, computers, books, walls and framing, human beings, and other items in all the affected floors. The fires reached sustained intense temperatures rarely observed in building conflagrations, in places exceeding 760 °C (1400 °F).
The north tower, 1 WTC, was impacted at 8:46:26 am and collapsed at 10:28:31 am, standing for 102 minutes and 5 seconds. The south tower, 2 WTC, was impacted at 9:02:54 am and collapsed at 9:59:04 am, standing for 56 minutes and 10 seconds. The fact that the north tower stood much longer than the south is attributed mainly to three facts: the region of impact was higher (so the gravity load on the most damaged area was lighter); the speed of the airplane was lower (so there was less impact damage); the affected floors had had their fire proofing partially upgraded. Also, the hottest part of the fire in the south tower burned near a corner of the building and apparently led to a sudden bursting of bolts in that section, while the failures in the north tower core involved slower warping and softening effects.
[edit]
Collapse of the two towers
Ground Zero debris with markup showing building locations.The two towers collapsed in markedly different ways, indicating that there were in fact two modes of failure. The north tower collapsed directly downwards, "pancaking" in on itself, while the south tower fell at an angle during which the top 20 or so stories of the building remained intact for the first few seconds of the collapse.
Subsequent modeling suggests that in the north tower the internal trusses supporting the building's concrete floors failed as a result of heat-induced warping. This placed additional stress on the bunched core columns, which themselves were losing integrity from both impact damage and heat. When the core columns gave out on one of the impact floors, this floor collapsed into the floor below. Once the collapse started, it was unstoppable; the huge mass of the falling structure had sufficient momentum to act as a battering ram, smashing through all the intact floors below. This theory is supported by witnesses from within the tower stating they heard "something like a heavy freight train approaching". There is some visual evidence that it was the core that collapsed first. It can be seen in videos that the large antenna, which was built on top of the core, starts downward a fraction of a second earlier than the rest of the building.
In the south tower, heat warping weakened the single-bolt connections between the floorplates and the initially intact external columns surrounding the impact hole, effectively creating a "hangman's drop" for that portion of the building above the point of failure. Eventually, the gravity load on these bolts increased beyond the breaking point as the joins, floorplates and columns weakened. Again, the momentum of the collapsing structure was sufficient to smash everything below it.
Oops, look like I just quoted most of the article. Try reading the whole thing, then answering MY question. I'm not here to answer your questions as to why planes made the WTC fall down. You are the one making the assertion that says otherwise, and I'm asking to provide proof, which is basically reading the article and pointing out what the things it says are false.
Kellimus, just so I know that you are qualified to make such conclusions that planes can't make a building fall down. Do you know how the towers were built? Exactly what kinds of forces were involved in the collapse? Can you give any numbers at all to back it up?