It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Thank you.
Some features of ATS will be disabled while you continue to use an ad-blocker.
Originally posted by Lumos
cms.firehouse.com: "Investigators discovered that while the jet fuel and the plane's contents burned up in a matter of minutes, the contents of the buildings, including the many office cubicles on the upper floors, continued burning until the structures collapsed."
So we're back to the "office fire causes complete structural collapse" theory? And that coming from NIST? Poor guys, I wouldn't wanna be in their shoes.
Originally posted by Lumos
How can pancaking, which calls for uniform instant collapse of one floor,
Originally posted by Lumos
How can pancaking, which calls for uniform instant collapse of one floor, occur when the floors themselves would have given in to the fires earlier and almost certainly non-uniformly?
from the link aboveA structure may fail to support its load when a connection snaps, or it bends until it is useless, or a member in tension either pulls apart or a crack forms that divides it, or a member in compression crushes and crumbles, or, finally, if a member in compression buckles, that is, moves laterally and shortens under a load it can no longer support. Of all of these modes of failure, buckling is probably the most common and most catastrophic.
Originally posted by Lumos
How can the explosive nature of the collapse, visible right from the very beginning, be explained by forces of gravity?
HowardRoarkWhat is your problem with that? Be specific, please.
No, it doesn't
Originally posted by Lumos
My problem with that, obviously, are the many examples of steelframe buildings who stood through much vaster office fires. I have trouble believing this wasn't crystal clear. If you want to further (intentionally?) sidetrack this discussion by posing irrelevant question after irrelevant question, do not count me in.
Originally posted by Lumos
How can pancaking, which calls for uniform instant collapse of one floor,
Originally posted by HowardRoark
No it doesn’t.
Originally posted by Lumos
Ok then, if "it doesn't", shed some insight on the process you envision in which only parts of the floor, not it's entire mass at once, tumble, resulting in the collapse of the subsequent floor(s).
Originally posted by Lumos
Furthermore, explain how the explosive features clearly visible for all the world to see, right at the initiation of the collapse when there was very little momentum, could've been caused by the compression of air within one story by one floor acted upon only by the forces of gravity. In case you succeed (...), put your theory in perspective regarding the buildup of air pressure from a floor not instantly, uniformly failing, completely negating the "syringe" analogy.
A Port Authority captain yelled at Lim to get moving, but he said, “You go ahead,” and he, too, put an arm around Harris, helping to carry her to the fourth floor.
That was when the wind started, even before the noise. “No one realizes about the wind,” says Komorowski.
The building was pancaking down from the top and, in the process, blasting air down the stairwell. The wind lifted Komorowski off his feet. “I was taking a staircase at a time,” he says, “It was a combination of me running and getting blown down.” Lim says Komorowski flew over him. Eight seconds later—that’s how long it took the building to come down—Komorowski landed three floors lower, in standing position, buried to his knees in pulverized Sheetrock and cement.
Lim landed near Harris. “If Josephine doesn’t slow me down, I’m dead,” he’d later say. “I figured this out.” That captain who’d urged Lim to go ahead didn’t make it. “Josephine Harris saved my life,” he says definitively. Harris landed on her side, clinging to the boot of Billy Butler.
Originally posted by HowardRoark
Originally posted by Lumos
How can pancaking, which calls for uniform instant collapse of one floor,
No it doesn’t.
How many other steel framed buildings which used no masonry in the structural frame, and were protected by sprayed on fireproofing were also hit by airplanes?
There is simply NO basis for comparison between the WTC towers and other buildings. However, if you think that you have a valid comparison, then please bring it up, so that we can evaluate it.
And what exactly makes the WTC so different in construction that when they collapse downwards, the mass that is supposedly driving the collapse can be utterly destroyed and yet the collapse will keep trucking right along at the same speed, regardless of loss of momentum, into even thicker and heavier floors? I'd really like to know what allowed that.
HR
Luminos, you seem to have some hostility issues.
HR
How many other steel framed buildings which used no masonry in the structural frame, and were protected by sprayed on fireproofing were also hit by airplanes?
There is simply NO basis for comparison between the WTC towers and other buildings. However, if you think that you have a valid comparison, then please bring it up, so that we can evaluate it.
HR
The term “pancaking” only refers to the impact of the falling mass causing the subsequent collapse of the lower portions of the building. Whether or not it was a global collapse or a local collapse is irrelevant.
HR
Perhaps this quote from one of the survivors who was INSIDE WTC 1 when it collapsed, can help you.
A Port Authority captain yelled at Lim to get moving, but he said, “You go ahead,” and he, too, put an arm around Harris, helping to carry her to the fourth floor.
That was when the wind started, even before the noise. “No one realizes about the wind,” says Komorowski.
Originally posted by Lumos
Alright, the basis for the comparison is simply that all buildings, no matter what their exact specs may be, have to qualify for certain structural standards of excessive stability. No one within their right minds would build a structure that comes even remotely close to collapse within default parameters.
Still, he recalls that he addressed the question of an airplane collision,
if only to satisfy his engineer's curiosity. For whatever reason,
Robertson took the time to calculate how well his towers would handle the
impact from a Boeing 707, the largest jetliner in service at the time. He
says that his calculations assumed a plane lost in a fog while searching
for an airport at relatively low speed, like the B-25 bomber. He concluded
that the towers would remain standing despite the force of the impact and
the hole it would punch out. The new technologies he had installed after
the motion experiments and wind-tunnel work had created a structure more
than strong enough to withstand such a blow.
Exactly how Robertson performed these calculations is apparently lost --
he says he cannot find a copy of the report. Several engineers who worked
with him at the time, including the director of his computer department,
say they have no recollection of ever seeing the study. But the Port
Authority, eager to mount a counterattack against Wien, seized on the
results -- and may in fact have exaggerated them. One architect working
for the Port Authority issued a statement to the press, covered in a
prominent article in The Times, explaining that Robertson's study proved
that the towers could withstand the impact of a jetliner moving at 600
miles an hour. That was perhaps three times the speed that Robertson had
considered. If Robertson saw the article in the paper, he never spoke up
about the discrepancy. No one else issued a correction, and the question
was answered in many people's minds: the towers were as safe as could be
expected, even in the most cataclysmic of circumstances.
There were only two problems. The first, of course, was that no study of
the impact of a 600-mile-an-hour plane ever existed. ''That's got nothing
to do with the reality of what we did,'' Robertson snapped when shown the
Port Authority architect's statement more than three decades later.
The second problem was that no one thought to take into account
the fires that would inevitably break out when the jetliner's fuel exploded, exactly
as the B-25's had. And if Wien was the trade center's Cassandra, fire
protection would become its Achilles' heel.
Originally posted by HowardRoark
And no, before you make the false claim: There were no design criteria for the buildings to withstand the impact of an airliner. No building has ever been built with that as a specific design criteria.
There were no design criteria for the buildings to withstand the impact of an airliner. No building has ever been built with that as a specific design criteria.
Originally posted by bsbray11
Disagreeing with the on-site construction manager of the WTC Towers now, eh? Based on something published on a blog? But either way, the towers still stood easily.
Originally posted by bsbray11
According to NIST you have to have a 75% column failure before a single floor can fail.
Originally posted by Krpano
HowardR
You are just trying to create disinformation.
Its well known that WTC towers were built to stand an impact of a 707.
Originally posted by Krpano
On July 28, 1945 a B52 crashed into Empire State building.
On May 20, 1946, another military airplane hit the 58th floor of a building on Wall Street.
None of them collapsed.
Originally posted by Krpano
Sir, you are a joke.
The 'smoke clouds' seen rising at the tower's base before they collpased was most likely from explosives in the sub ground level demolishing the core super structure. This in turn would cause vertical fall of the core while other thermite charges were detonated at 30 floor intervals cauing a uniform an explosive global collapse.
the volume of put options — instruments that pay off only when a stock drops in price — surged in the parent companies of United Airlines on September 6 and American Airlines on September 10 — highly suspicious trading on its face. Yet, further investigation has revealed that the trading had no connection with 9/11. A single U.S.-based institutional investor with no conceivable ties to al Qaeda purchased 95 percent of the UAL puts on September 6 as part of a trading strategy that also included buying 115,000 shares of American on September 10.
Originally posted by HowardRoark
Originally posted by bsbray11
According to NIST you have to have a 75% column failure before a single floor can fail.
Can you give a specific reference to where that statement is made?
CALCULATION:
200000 / 110 = 1818 tons = 1818000 kg
CALCULATION:
200 * 200 = 40000
40000 * 82 = 3280000 lbs = 1487783 kg = 1488 tons
CALCULATION:
1818 + 1488 = 3306 tons
CALCULATION:
60 * 2.25 = 135
40 * 5 = 200
135 + 200 = 335
335 / 100 = 3.35
The perimeter columns essentially had enough reserve capacity to carry 200% of the WTC 1 design load [According to the safety ratings NIST released]. The core columns could carry 135% [According to the same safety ratings]. For floor 97 to collapse, the equivalent of 55% of the core columns and 80% of the perimeter columns would have to fail. That means on average 26 core columns and 189 perimeter columns would have to fail. 75% of the total columns would have to fail.
Originally posted by Jedi_Master
So if they blew out the bottom first, wouldn't the building collapse start in the basement first instead of at the top down?
Keep in mind that this is a DRAFT version of a paper. A rigorous peer review is necessary before anyone firmly accepts this paper's findings. A careful frame-by-frame analysis of videos, a more detailed modeling of the fire, collapse, and clouds, should be done to confirm measurements and observations.
Originally posted by LeftBehind
Keep in mind that Trumpman also says this.
Originally posted by davenman
WHY? Assuming that the buildings were brought down in a controlled demolition, why was it important to totally demolish all 3 buildings? Why not just one?