BUILDING SAFETY: Since September 11th, Leslie Robertson has not slept easy in his bed. Michael Ellison talks to the man who designed the World Trade Centre's safety features
Leslie Robertson needs to catch up with his writing, a task that he would usually approach with enthusiasm. He might even have pursued a career crafting sentences, had he been able to find the right job. Instead, he became a structural engineer, a builder and designer of such diverse projects as the Bank of China tower in Hong Kong, a library in Latvia, a supermarket in Florida, the Rock and Roll Hall of Fame in Ohio, a museum in Berlin and numerous corporate headquarters.
Along the way, Robertson and his firm have worked on three of the six tallest buildings in the world. The remains of one of them are being pushed around by what look like Tonka toys, viewed from his offices two blocks away and 47 floors aloft: the World Trade Centre.
"No matter how you turn it around, that building I designed fell on something like 3,000 people and you can't make that go away," he says, pausing to let go a sigh. Every night since September 11th Robertson has had trouble sleeping and he has black rings under the brown eyes that flicker occasionally towards the killing ground as he speaks.
All around him are triggers that release images of the terrorist attacks, though the smell and taste of smoke from the eradication of what was once the world's tallest building have faded now. There is the scar in the ground to the north-west of Robertson's building in lower Manhattan; in the lobby by the elevators a photocopy of a newspaper article headlined, optimistically, "Air near ground zero is rated safe by Feds"; in the suite of offices, a large photograph of the two 110-storey structures in a flaming orange light on one wall, on another a model of the area tilted on its side, the towers protruding, each topped with a little US flag.
His receptionist is hemmed in by an L-shaped counter, a steel girder rests on top of one section, the 1971 grand award for excellence from the New York Association of Consulting Engineers for the firm's work on the World Trade Centre is resting temporarily on the other. The wire from which it once hung is broken now.
"A lot of people, a lot of families and individuals have been impacted by this event and I think there's a responsibility to speak to them about what it was that we did, what was our responsibility," he says, using his hands to give form to ideas. "Our responsibility was enormous." Yet he has rather fallen behind in writing to relatives of victims.
"They probably think I'm terribly coarse and crude in not responding, but I've been very busy and it's not easy to decide what to say." He cannot reply to everybody because of the vast numbers of people who have been in touch; telephone calls, about 1,000 letters - only one critical, he says - and even three proposals of marriage. Robertson toys with his gold wedding ring as he laughs this off.
And he can laugh, despite the enormous burden he has taken upon himself.
"It's a huge chore I have in front of me. My responsibility was to conceive and direct the various research activities. The robustness and stamina of the buildings is my responsibility. All the drawings have my name on them." After the World Trade Centre was bombed in 1993, one of the early manifestations of Bin Ladenism, Robertson and others in his firm went public. It was necessary, he says, to persuade people that it was safe to return to work in the buildings. Then, he had something useful to say immediately; after September 11th, and perhaps in the light of his previous reassurance, he did not.
"I know more about the project and more than anyone ever will about the design. There's no one alive today who's even close to what's stored away in my head, and I've got a memory like a sieve. It's true that, following the event, a lot of people - architects and engineers - stepped up to the interview platform and had their say and, by and large, most of them spoke much too quickly and without a lot of knowledge. There's a need to understand what should be said before saying things." So Robertson remained silent, or if not silent, then at least private. Even this did not quite come off. He had agreed 18 months earlier to speak at a meeting of the National Council of Structural Engineers, in New Hampshire, in early October and went ahead with the engagement.
He was astonished later to see a report of the meeting in the Wall Street Journal. Robertson was asked: "Is there anything you wish you had done differently in the design of the building?" Instead of answering, he wept.
"I guess I thought I was a sturdier person than I am," he says now. "The thing that keeps you awake at night is the people in the building. Pretty much every night." One thing that does not keep Robertson awake at nights is the thought that the 1,350 ft-tall World Trade Centre should have been built to absorb the impact of a jet airliner: it was.
THE team had in mind the B-25 bomber that hit the Empire State Building in the fog in 1945, killing 14 people. But that aircraft was nothing compared with the Boeing 707 that really concerned Robertson when he was working on the twin towers in the 1960s, and the 707, in turn, had nothing on the 767s that struck on September 11th.
"And if these people had chosen 747s instead of 767s, it definitely could have been worse. Does that give people comfort? I don't know. It's clear that it is necessary to keep aeroplanes away from buildings. The World Trade Centre was stalwart. Very, very few buildings would have done any better, or as well, under the circumstances.
"This is a 40-year-old project. If I didn't learn anything in 40 years I should be hung by my thumbs. You should have done this, you should have done that . . .
"If we were designing now we would start with the question of the 747 or the new airbus. You might even come away with a less robust building, because you might think there's nothing you can do about it.
"In retrospect, I would have made them sturdier. But making them sturdier doesn't mean that they would have stood up, because the failure was the result of removal of the structure by the plane and degradation by the fires."
Robertson counsels that there are no absolutes in his discipline, that we are not talking about a fine Swiss watch, that imperfect materials are employed to construct imperfect buildings, that each structure has its strengths and weaknesses. He worked on the World Trade Centre with his then partner, John Skilling. Skilling and the architect, Minoru Yamasaki, are both dead now.
Of the three, only the architect is mentioned in Divided We Stand: A Biography of New York City's World Trade Centre by Eric Dalton. And yet Robertson, who was in Hong Kong when the hijackers attacked, insists still: "Whether strength and reserve strength were in the buildings was my responsibility." Not that he has any time for the book. "There's a lot to be said for obscurity, because you don't have to deal with people who write long and, I thought, not all that interesting books," says the structural engineer whose nights are filled with the dread of one whose 1960s precautions were inadequate against the most startling event of the new century.
- (Guardian Service)