81 years ago, today, Nov 7 1940

“Some days are like this even in… Tacoma Washington” to paraphrase another saying I know when unfortunately things go astray.

 

This is one of several short videos taken as the Tacoma Narrow Bridge, just 4 months old, tore itself apart during a series of wind gusts back in 1940.

 

This event and its film footage have been fundamental reading and study for structural and dynamic systems engineers for decades now, the interaction of a forcing function on a dynamic structure and the huge effects of operating near a structure’s (or system’s) natural frequency.

 

Fortunately, here the bridge was closed just shortly before this film was taken. No one was killed, as the driver of the car managed to escape before the structure collapsed, however, his dog, in the car was lost and neither were ever found.

 

A new bridge was built, using some of the same supports, in 1950 and still stands today. I’ve been on it myself. A second parallel span was added in the 2000s.

 

When built in the 1940 it was the 3rd longest suspension bridge in the world.

 

I hope you all are well, in this crazy up and down world we live in at the moment.

 

Hugs, Becky

 

Done