I always get a little frisson of engineering joy when I drive over the Tacoma Narrows bridge. For the non-engineers in the audience, the first Tacoma Narrows bridge famously twisted itself to destruction in a 42-mph wind.
The bridge was obviously unstable even during initial construction (as documented in “Catastrophe to Triumph: Bridges of the Tacoma Narrows.”) And so when it started to collapse, several movie cameras were there to document the event, which is still studied and analyzed today.
Today, people are tired of hearing about bridges collapsing. These stories undercut confidence, and bridge professionals are on top of things (ahem). When a bridge collapses, there’s a risk of a lawsuit, and if that was happening, no company could deliver bridges at a reasonable price. We cannot account for the way that wind behaves in the complex fiords of the Puget Sound.
Of course, these are not the excuses of bridge builders, but of security professionals.
I always get a little frisson of engineering joy when I drive over the Tacoma Narrows bridge, and marvel at how we’ve learned from previous failures.