 |
October 19, 2001
September 11, 2001 will be permanently etched into the national consciousness. The attack on the World
Trade Center complex resulted in more than 5000 people killed or missing, billions in economic losses, significant
interruption and slowdown in business activities, a temporary meltdown in the stock market, and ultimately a declaration
of war against the perpetrators of this insidious attack. This drama continues to unfold everyday with news of further
terrorist attacks. Attacks by bio-terrorism using anthrax adds another chilling dimensions to realities that we face
each day. Terrorists' ultimate goal is to reign chaos and anarchy to our orderly society. They kill and destroy indiscriminately.
We, as engineers, work tirelessly to design and create buildings and structures that are safe and secure for people. Engineers
are also scientists. Therefore, we cannot escape the need to study this tragedy from an analytical viewpoint. Review of the
collapse mechanism and understanding any of the significant contributing factors may lead to design of safer buildings in the
future. The lead engineer for the World Trade Center Towers, Leslie E. Robertson, recently was profiled in a Wall Street
Journal article published on Oct. 12, 2001. Here are some interesting excerpts:
|
|
|
MANCHESTER, N.H. -- Until this past weekend, the principal engineer of the World Trade Center had said little publicly about the total destruction of his signature work. But 73-year-old Leslie E. Robertson broke his silence at a gathering of fellow structural engineers here, reviewing the project that he began as a 34-year-old wunderkind. What began as a matter-of-fact slide presentation soon became an emotional experience. Mr. Robertson began his review by flicking through slides of prefabricated exterior panels being hoisted into place in the early 1970s. Gripping the lectern, he faltered. "Oh boy," he said, bowing his head. He gathered himself. "Next slide." He used a laser pointer to highlight grim photos of Ground Zero: exterior panels torn into jagged sections, twisted steel columns, towering piles of rubble. The commentary continued, like a medical examiner detailing an autopsy. "Here you see classical tension failure. Next slide. You can see the columns displaced. Welds are sheared off. Classical failures. Next slide." Then came the question-and-answer period. "Is there anything you wish you had done differently in the design of the building?" one engineer called out abruptly. The room fell silent. Mr. Robertson paused and scratched his head. "I guess I wish I had made it stand up longer," he said, his voice trailing off. "I mean, every man was important..." He stood alone at the lectern and wept. Another engineer, his voice breaking, called out: "I think you did a great job." The audience burst into passionate applause. |
|
|