Bill Wyman
Why the towers collapsed
The jetliners hit the World Trade Center buildings at a vulnerable point.
The World Trade Center’s twin towers were the tallest buildings in the world at the time of their opening in 1970. They each stood 110 stories and more than 1,300 feet tall. They are the dominant features in an enormous office complex totaling more than 9 million square feet of office space and together make up one of the most recognizable architectural landmarks in the world.
Today they were reduced to heaps of rubble after one of the worst catastrophes in U.S. history. A pair of jetliners crashed into them Tuesday morning — at precisely the points at which they would do the most damage, according to architectural experts. The impacts created fires and, ultimately, brought about the collapse of both buildings.
Why did the buildings collapse?
According to Gregory Fenves, a professor of Civil Engineering at the University of California at Berkeley, the planes weakened the buildings’ structures at key points. Fenves, working on information gleaned from preliminary TV reports, stressed that he was speculating. He said that if the planes had hit the structures higher, they could have merely damaged their tops; if they had hit lower, they would have been up against the enormous weight and resistance of the base of the buildings.
The buildings were architecturally interesting in many ways. Each structure is based on a central steel core, which is surrounded by the outside wall, a 209-foot by 209-foot cube of 18-inch tubular steel columns, set 22 inches apart. The cores and “tube walls” share the enormous physical weight of the structures and protect them against the extraordinary wind forces of buildings that tall. There are trusses that support each floor, but no other columns between the cores and outside walls. Some floors contain nearly 40,000 square feet of open office space.
News reports said the planes were jetliners, a 757 and a 767. The 757 has a 124-foot wingspan, is 155 feet long and can weigh 100 tons. A 767 is bigger, with a 156-foot wingspan and 159-foot length and can weigh a maximum of 200 tons. (A 747 is more than 200 feet long and can weigh 400 tons.)
The planes hit the buildings near the 70th or 80th floors. Their impact severely damaged the tube walls, which carried a large proportion of the buildings’ weight. CNN footage of the second plane hitting a tower appeared to show that a large part of the jetliner went all the way through the building, suggesting that the interior core was also damaged.
Once a building like a World Trade Center tower loses some of its support, the building in effect goes to work, Fenves said. “The loads are trying to redistribute,” he said. “The loads are figuring out how to get back down to the ground.” At the same time, he noted, the fires are deforming the physical properties of the support steel.
“It’s a very rugged system,” he said. “It takes a long time for the collapse mechanism to develop. It’s not like kicking the leg out from underneath a chair. The building is 200-foot square and there’s a lot of structural system there.”
But once the upper floors began to give way, terrible force was set in motion. Each floor of a building that big might weigh 6 million pounds, he said. Once impact is factored in as well, he said, the force becomes irresistible.
The disaster is a terrible echo of another disaster involving a New York landmark.
On July 28, 1945, a B-25 bomber slammed into the north side of the Empire State Building, then the tallest building in the world. A reckless pilot was flying over Manhattan in poor visibility; it was apparently an accident. Thirteen people died, mostly in fires started by burning gasoline.
The Empire State Building, Fenves noted, was built during the Depression, and made with a much heavier structural system. The bomber in that accident was also a much smaller plane, said Fenves.
The WTC buildings’ official names are One and Two World Trade Center; their respective heights are 1,368 and 1,362 feet tall. They are part of a massive seven-building complex near the southeastern end of Manhattan. The center’s architect was Minoru Yamasaki. The engineers were John Skilling and Leslie Robertson of Worthington, Skilling, Helle and Jackson.
The complex cost $350 million in 1966, or nearly $2 billion in today’s dollars. Ground was broken in 1966, and the buildings opened in 1970, but the complete center was not finished until 1974; there are now seven total buildings, a large shopping mall, and an enormous garage. An observation deck is a popular tourist destination. Beneath the center two New York subway lines converge; there is also the Manhattan terminus of PATH commuter trains from New Jersey.
The center has been the target of an attack before. On Feb. 26, 1993, terrorists planned and carried out a truck bombing in the parking garage. Prosecutors said the weapon was a 1,200-pound truck bomb. Six people died and more than 1,000 were injured in the attack. The explosion created a five-story crater beneath the building, but its structure held.
After the center opened in 1970, for several years it was feared the complex would become a real-estate white elephant. But for decades it then reigned as one of New York City’s premier office buildings. A recent press release from the New York and New Jersey Port Authorities, which own the building, says that more than 430 companies from 28 countries are tenants. The authorities said that 40,000 employees work in the buildings daily, besides 140,000 daily visitors.
The World Trade Center lost its position as the world’s tallest building in 1974, when the Sears Tower in Chicago opened. In 1998 the two Petronas Towers in Kuala Lumpur, Malaysia, opened; they are each more than 100 feet taller than the World Trade Center structures.
The Oscars’ growing sequel problem
Fewer and fewer people are watching the Academy Awards every year. Blame "Transformers"
Johnny Depp, Jean Dujardin, and a transformer from "Dark of the Moon" Three years ago, the Oscars announced the biggest change in its workings in decades. It expanded the best picture lineup to 10 films, up from five. We’ve seen two Oscarcasts since; the third one will be broadcast this Sunday on ABC.
The Academy of Motion Picture Arts & Sciences, which puts on the show, doesn’t admit it, but the tweaks are born of a concern about one thing and one thing only: TV ratings. The academy makes a mint each year off the broadcast, traditionally one of the year’s biggest shows. But the trend line for viewership has been heading downward for more than a decade. The academy’s not in the poorhouse or anything; it can still charge an ever-growing premium for advertising, of course. But the show’s not cheap, either, and those declining ratings are a very real indicator of the once fabled awards show’s fading glory.
Continue Reading CloseMichael Jackson’s celebrity suicide
Born to stardom, he never knew what it was like to live or even behave normally
CNN’s coverage of Michael Jackson’s sudden illness in the minutes before his death was reported captured nicely the way the media has treated him. Nutty people were allowed to talk at length, including a guy who kept saying his concerts in London were in 2010. (They were scheduled for next month.)
Wolf Blitzer looked into the camera to tell us earnestly that the head of the concert promotion company had told them that Jackson was in “tip-top shape,” and that he’d passed a health exam “with flying colors.”
Continue Reading CloseWhitewashing Roman Polanski
More than 30 years after he raped a 13-year-old girl, the fugitive director hoped a skewed documentary would reopen his case. Thankfully, a judge said no dice.
Bad art is supposed to be harmless, but the 2008 film “Roman Polanski: Wanted and Desired,” about the notorious child-sex case against the fugitive director, has become an absolute menace. For months, lawyers for the filmmaker have been maneuvering to get the Los Angeles courts to dismiss Polanski’s 1978 conviction, based on supposed judicial misconduct uncovered in the documentary. On Tuesday, Los Angeles Superior Court Judge Peter Espinoza ruled that if Polanski, who fled on the eve of his sentencing, in March 1978, wanted to challenge his conviction, he could — by coming back and turning himself in.
Continue Reading Close“The Last Waltz”
A new DVD remembers when Martin Scorsese captured a beautiful moment before the Band -- along with Bob Dylan, Van Morrison and Joni Mitchell -- ceased to matter at all.
More than 25 years on, it’s a little hard to explain “The Last Waltz.” Rock ‘n’ roll, pop and hip-hop permeate our lives. The music blasts from commercials; you can hear the Ramones in the bar of an expensive restaurant; Joni Mitchell songs anchor an episode of “Ally McBeal.” More than that, you can see rock — and see it well — on a slew of cable channels; fans can find exquisitely filmed concert footage (and fake concert footage) of virtually any artist they’re interested in. More than that, the rock video industry, unaccountably, has found itself frequently setting the standard for film technology and construction.
Continue Reading Close“Seinfeld”
Jerry Seinfeld and Larry David's TV show wasn't just a sitcom -- it was one of the most complex and troubling art works of our time.
Walk through the great museums or churches of Rome or Paris and marvel at a curious thing. You don’t have to be a cultural nostalgist to admit that, if nothing else, the artists of the past seemed technical masters of their media in a way that almost nothing today approaches. The degree of precision in sculpture and painting — the breathtaking emotions and the almost hallucinatory details — seem to have no counterpart in the present age.
In the mechanical or structural sense, the modern era has its areas of precision. But these are most often hidden with a patina of sparseness or repetition, as in our great skyscrapers. There are technicians, sometimes acclaimed, at work in film (Steven Spielberg, Ridley Scott) but they are emotionally crude and too often manipulative. Indeed, the modern age has come to make us view technical brilliance in the arts a bit suspiciously. Why? Are our artists today just not detail-minded? Do they lack the patience, the imagination, to work on such a precise level? Is detail on that level just not part of contemporary culture?
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