Structural engineer unimpressed by suspension bridge collapse scenes in movies

Engineer Alex Weinberg reviews suspension bridge scenes in movies and finds their representation of structural mechanics to be wobbly at best.

Embedded above is the most accurate he found, from Final Destination V.

The origin of the structural failure in this situation is pretty absurd because the asphalt driving surface on a traffic bridge is non-structural. The road itself rests on a steel structure, which would probably not be seriously compromised by some sawing and jackhammering on the asphalt. Further, it’s hard to invent a scenario in which any of this could cause a failure at the top of a vertical suspender. But who knows, maybe there had been some plot-friendly corrosion in the steel. Regardless of the initial cause of failure, the collapse progresses in a halfway believable manner: The road deck falls, but the main catenary cables and the bridge towers remain. With no road to support, the vertical cables swing dumbly over the void.

Most scenes, however, are very bad indeed, like this one from The Dark Knight Rises. "I consider this the worst suspension bridge destruction scene in motion picture history," he writes.

His roundup serves as a nice overview of the symbolism of suspension bridges, too. Alas, our directors score only 2 unnerving metallic whipping noises out of 10. Must try harder! [via]