I came across the following video on Power Line, as part of a poll asking whether it or footage of the explosion of the Hindenburg Blimp best capture the sense of the Obama administration’s coming apart. I vote for this one. If it does, indeed, come apart.
But that’s another matter. I have to say I found this video, which I’d never seen before, fascinating. My husband, as an engineer, had seen it before, early on in his engineering studies. It’s used now as a study case for what happens when you fail to take into account resonance.
I think it’s a study case for what happens when you think you know everything and are trying to save money.
According the Wikipedia, the 1940 Tacoma Narrows Bridge was the third longest suspension bridge in the US, following number two, the George Washington Bridge in New York City and number one, the Golden Gate Bridge in San Francisco, which had the longest suspension bridge main span in the world at the time of its completion. Tacoma Narrows was designed by a man, Leon Moisseiff, who had worked on the other two bridges, but in this case had an eye to cutting costs. The original design projected costs at $11 million whereas Moisseiff’s was projected to cost $8 million. It would be “slimmer and more elegant” as well.
It was completed and opened to traffic in July of 1940 and collapsed 4 months later on November 7. There was no loss of life in the collapse save that of a three-legged cocker spaniel named Tubby, who was so terrified he refused to leave the car he was in, which the driver had abandoned.
I could try to describe the undulations, but since I have the video, I’ll just let you watch it. It’s only about 3 minutes long. I especially like this version with the eerie music of Christopher Payne. They say you could walk along the center line and not be moved up or down, even as the sides were roiling about you.
What this says to me, though is that Man is fallible and always will be, but never more than when he thinks he is not.