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More WTC News
Current WTC happenings: The FBI is searching ISPs with FISA warrants. Architects and civil engineers are starting to speculate on why the towers collapsed. Pictures: NASA, a powerful photoessay, newspaper headlines. Current investigation news: LA Times, NY Times, CNN. They're finally starting to mention casualty figures. Finally, bjb writes: "It isn't the hollywood blockbuster of a story, but I'm a daily reader of Slashdot, and I was on the 38th floor of the WTC 1 building when the first plane hit. Oh, and I was reading Slashdot at the time. You can read about my experience here. It was originally an email that I sent out to friends and family, but I was asked by NPR's Talk of the Nation to make it a web page."
As everyone knows by know, Morgan Stanley Dean Whitter occupied roughly 10% of the WTC, with some 3500 employees. There's a good article on Yahoo this morning about their offsite back strategy, and how it enabled them to start working again almost immediately.
Last night on ABC, Peter Jennings interviewed an engineer who said that the WTC had enough steel to withstand the impact...
According to him, exposing the steel to 1000F heat for an hour was what finally caused it to fail...
Goofy, Geeky Gifts and More!
My boyfriend is a professional structural engineer who has done a lot of work on major LA buildings. He's currently attending Berkeley for a masters in Structural Engineering and, in chatting with his professors, came to this (paraphrased):
1) Yes, the buildings did withstand the impact of the airplanes. They didn't fall immediately, did they?
2) Buildings are built to a certain fire code, in that the building won't completely catch on fire and collapse for a certain length of time (usu 1hr?). The escape routes are located generally in the four corners. Since the plane took out one of them, this means that the required escape time is now 2+ hours.
3) Jet fuel burns with a much higher temperature than normal fuel.
4) Steel expands and crystalizes under extreme heat. Since the plane(s) hit at a "centre"-ish spot, the steel tried to expand up and down, but since the steel in the "up" and "down" weren't hot and wouldn't move, the steel in the "centre" buckled.
5) Since jetfuel burns hotter, step 4 happened faster and also reduced the "buckle" time by a certain amount - when used along with the increased escape time required, means that considerably fewer people would be able to escape.
6) Since the steel buckled, the upper floors now come crashing down on to the floor immediately below. Being as that floor is not suited to hold X number of upper floors MOVING rapidly at it, it collapsed and repeat until bottom.
Therefore, it was the fire that made the buildings collapse, not the impact of the planes.
-mrsmalkav
There's a reasonably good diagram of the affected areas here. (Requires shockwave) For NYC specifically, click on the NYC link on this map. The buildings down or in danger are in red. Manhattan island has been almost completely shut down from 14th Street south. That's about 1/6th of the island.
There is an interesting Ny Times article which describes a reporter's interviews with Afghanistan People.
[A] 25-year-old constable sat on the floor beneath a single dangling light bulb. His name was Muhammad Anwar. He had heard something about the attack in America but he had no idea how many were killed or what cities were involved. Indeed, it seemed unlikely that he had ever heard of New York.
"Attacks like these are not a good thing because Muslims live all over the world and Muslims may have been killed," Mr. Anwar said hesitantly. By his reckoning, Americans were enemies of Afghanistan, as were Jews and Christians. He thought about this a bit more and retracted it partially. "There must have been all kinds of people in the building, not just bad Jews but good Jews, not just bad Christians but good ones." He remembered something he had learned in his madrassa, or religious school. "It is un-Islamic to kill innocent people," he said.
The towers were designed with airplane disasters in mind: Built in the 1970s, World Trade Center Twin Towers in New York City were designed to withstand normal fires and hurricane-force winds. According to some reports, engineers believed that even the impact of a Boeing 707 would not bring down the towers. (from: http://architecture.about.com/library/weekly/aa091 201a.htm)
After all, in 1945 a B-25 bomber flew into the Empire State Building, killing 13 (but not knocking down the building).
Interesting reading:
- Terror in the Mind of God: the Global Rise of Religious Violence
- Political Islam
Meanwhile, in Australia they are already stoning school buses with Islamic kids on them... (I have a rant about this on my home page.)Danny
[I have written 600 book reviews]
I have written over 900 book reviews
And like the articles also said, once the weight of the upper floors started to come down, it took out the floor support beams that also kept the outer skeleton in place.
The steel only buckled right around the fire, but once those supports were removed, the skeleton was then able to buckle and move in ways that buildings shouldn't.
Also, on the escape time, the fire from the fuel probably made passage from the above floors through the escape routes nigh impossible. So pretty much if you were above the point of impact, you were in trouble. After the first impact, they had people from around the 90th floor calling on cel phones talking about the heat and smoke, saying "We're fucking dieing up here".
But yes, the fire is the cause, hence the choosing of planes heading across the country from a "local" airport - LOTS of fuel.
> Notably in the fact that Islam was spread initially by military conquest. Christianity was spread by word of mouth and people willing to die for it- but not fight for it with violence.
They probably didn't teach you in Sunday School that most of continental Europe (outside the borders of the Roman Empire) was "Christianized" at swordpoint.
To say nothing of the spread of Christianity beyond Europe during the Colonial Era. (Indeed, there was a doctrine [called repartimenta, IIRC], that essentially justified enslavement of the natives as a way for them to "repay" the Europeans for having troubled themselves to sail across the seas to save their souls.
Don't confuse ideology with history.
Sheesh, evil *and* a jerk. -- Jade
If they are really lying, they did a nice job changing the pictures... This is supposedly a picture of Palestinians celebrating on Tuesday. Notice the little boy. He's wearing a Brazilian national soccer team shirt. And this shirt is quite different from the ones used in 1991. Actually, this one is pretty recent, I think it was used the first time around the 1998 world cup.
I can't say if the picture is really from Tuesday, but it really can raise some questions about this "indie" article. That, and the fact that I live in Brazil and haven't heard a word from anyone at the University of Campinas about this.
Marcelo Vanzin
CNN has been known on many occasions to get the news wrong, or fabricate stories (Wolf Blitzer).
However, this time, they are reporting the truth. www.haaretzdaily.com , one of Israel's better independent newspapers also reported this story, and took photos on site, from the past few days, not 1991.
The story at Indymedia was posted by a Brazilian. I think I'll trust sources in Israel instead of someone in South America, Thank You very much.
Steel (and Iron for that matter) have a number of differenty possible crystal structures, which vary widely in the strentgh, maleability and brittleness. The rusting rate also changes, but that is not interesting in this context, but it is for the design of blades and tooling. The oldest way to change the crystal structure of iron or steel is to heat it up to a certain temperature, then cool it in a controlled way. Fast cooling leads to a hard brittle structure, slower cooling leads to a more malleable structure. Heat the surface and cool it quickly and you've got case-hardened metal in hand. The key thing to remember is (as any blacksmith has experienced at some time or other) iron gets brittle before it gets to the cherry red stage.
I assume that there was both heat-related sag and a brittle region beyond that as you moved farther from the hottest flames. So, it is possible that the metal did, in fact, get brittle and snap in the heat, along with the sagging, leading to a sudden pancake type collapse.
Who would have thought that you needed to plan for hundreds or thousands of gallons of aircraft fuel when sizing fire supression gear in a tower?
As reported in today's WashPost Style Section, The Coup has changed the artwork.
No-one except Tom Clancy, that is.
not a big surprise, but more trains & cars have been added.
sulli
RTFJ.