Replace the rubble of the WTC with a memorial park, then burn down the UN building and make that into a memorial park as well.
My understanding is that the external tubular "lattice frame" was a new innovation at the time, and it was considered crucial in the design of any large structure because it minimized the amount of usable floor space that would be lost to internal columns. I don't mean to imply that the design was substandard, but I believe the World Trade Center was not required to meet City of New York building codes because the Port Authority of NY & NJ is a semi-autonomous agency that operates under its own regulations.
Were there more than one "sect" involved in this hideous destruction of life?
I doubt it. The planes would have taken down the towers if they had hit anywhere except the top floors. The structural support would burn away anywhere.
That's one problem I have with these forums, there's too much uninformed speculation out there, and then others repeat this as fact.
This article kills that conspiracy theory, hopefully.
http://www.freerepublic.com/forum/a3b9e390647f1.htm
17 Posted on 09/11/2001 09:32:42 PDT by Plummz:
A word on the structure of the WTC towers: The WTC towers had a distinctive structural system which utilized the exterior wall framing for lateral bracing -- a so-called lattice framework. This allowed minimization of internal lateral bracing and opened up the floor plans. You can see the effect of that when the buildings collapsed, with the lattice framework crumbling and the interior imploding. The lattice works so long as it remains intact as a system: if a part of it goes, then the whole systemgoes. The planes punched holes in the lattice, one tower punched on two sides, maybe the other too. Portions of the lattice of the second tower briefly remained standing after the collapse,then fell. The system was considered daring at the time of construction, for it distributed loads more efficiently than legacy column-and-beam-supported systems. Probably the legacy systems would not have totally collapsed due to damage at upper floors, although floors above the damage would have come down if columns wereweakened.**********
The WTC towers performed admirably today and they managed to stand even after the massive impacts that destroyed much of the integrity of the perimeter columns. I suspect that as the airliners passed through the buildings they also heavily damaged the interior core (and likely severed exist stairs to those trapped above the impact points).
The final reason the towers all fell today was fire. Fire is incredibly destructive, even to a hi-rise sturcture that seems to be fire proof. the reality is at high enough temperature, steel and concrete burns and vaporizes. It was only a matter of time before the nominal 2-3 hour of fireproofing protection applied to all structural members disintegrated under the intense heat of thousands of gallons of aviation kerosene burning unchecked.
This is what happened to the WTC towers 1, 2 and 3.
All buildings in the Unites States are subject to similar rigorous safety and fire codes but obviously none can save a building subject to intentional suicide bombings by large airliners. Unless you want to work in underground bunkers, NO BUILDINGS ARE 100% SAFE FROM TERRORIST ATTACKS!
I also watched from my roof as the WTC towers collapsed after I saw occupants jump 80 floors to their deaths.
MASSIVE amounts of fuel.
re the resources and expertise required to pull off today's attacks, it's plausible that it could've been done by less than 10 people, with less than $75,000, and no more flight experience than that offered by a couple of months drilling on microsoft flight simulator. all day long people are making the attackers out as possibly much more sophisticated and financed than perhaps they were; they were precise, dedicated, and fanatical, but not necessarily wealthy or well connected. if we don't reach the logical conclusions from that reality and act accordingly, we're going to have a long haul of being the world's new sitting ducks.
The image of the World Trade Center's 110-story twin towers crumbling seemed a scene of impossible destruction.
But the miraculous steel and concrete architecture that made them could not withstand the power of Tuesday's attack and ensuing fire. No building designed today could, said Masoud Sanayei, a
civil engineering professor at Tufts University.
Experts in skyscraper construction said video of the collapse led them to believe the towers were perhaps weakened by the initial impact of the airplanes that hit them Tuesday, but that heat from
the resulting fire was likely the most punishing blow.
Hyman Brown, a University of Colorado civil engineering professor and the Trade Center's construction manager, speculated that flames fueled by thousands of gallons of aviation fuel melted
steel supports.
''This building would have stood had a plane or a force caused by a plane smashed into it,'' he said. ''But steel melts, and 24,000 gallons of aviation fluid melted the steel. Nothing is designed or will be designed to withstand that fire.''
Sanayei said the heat may have disconnected one of the towers' concrete floors from the tubular steel columns that ringed the buildings. If one or two floors collapsed, it would have created a
pancake effect of one massive floor caving into the next.
''In my opinion, the fire weakened the connection between the floor system and the columns on the higher floors and caused a couple of the floors to collapse,'' Sanayei said. ''The floors are very heavy, made of reinforced concrete, so when one hits the next, they cause a domino effect ... and it can go all the way down to the first floor.''
Architect Minoru Yamasaki, who died in 1986, worked with engineers John Skilling and Leslie E. Robertson to design the fabled twin towers, once the world's tallest buildings.
In his 2000 book ''Building Big,'' architect David MaCaulay described the towers' engineering as ''a series of load bearing exterior columns spaced 3 feet apart and tied together at every floor by a deep horizontal beam, creating a strong lattice of square tubing around each tower.''
The core surrounding the elevators inside was much the same, with a giant lattice work of steel covered by poured concrete connecting the interior columns to the exterior ones. The design was free enough for each of the towers to hold 4 million square feet of space unencumbered by columns or load bearing walls.
Sections of exterior wall were wrapped around the outside in 24- and 36-foot high sections, creating a sort of patchwork so that not all the floor joints would meet walls at the same height, according
to MaCaulay.
Both Brown and Saw-teen See, a managing partner in Robertson's engineering firm, said the twin towers were originally designed to sustain a direct hit by a large jetliner, but that such construction couldn't make them fire- or bombproof.
Brown said it appeared the attack was meticulously planned.
''If they did it lower in the building the fire department could have gotten to it sooner. In its simplicity, it was brilliant.''
He said that the two towers have staircases in all four corners of the buildings and were designed to be evacuated in an hour, but it appeared that since the planes crashed into the corners, escape
was cut off for those on the floors above. ''I could never conceive of anybody being able to bring down
those two buildings,'' Brown added.
Minoru Yamasaki Associates issued a statement Tuesday saying the firm was in contact with authorities and had offered assistance.
''We believe that any speculation regarding the specifics of these tragic events would be irresponsible,'' the statement said. ''For obvious reasons, MYA has no further comment at this time.''