On This Day in Science History - November 7 - Tacoma Narrows Bridge

On November 7, 1940, the bridge spanning Puget Sound across the Tacoma Narrows in Washington state dramatically collapsed. The bridge opened on July 1, 1940 as the third longest suspension bridge in the world. Almost immediately, the bridge was nicknamed "Gallopin' Gertie" because of its sway due to the wind. The state hired an engineer to propose methods to settle Gertie's galloping tendencies. They concluded their study on November 2, 1940 and recommended a couple of options to fix the problem. Unfortunately, the bridge didn't wait for the repairs.

On the morning of November 7, the winds were pretty strong and the bridge swayed more than usual. As the wind speed built up during the morning, the swaying approached the resonant frequency of the bridge itself. The bridge span began to jump and sway until it ripped itself apart at 11:00. Because of the long period of time it took to reach the breaking point, local camera shop owner Barney Elliott was able to film the collapse. This film is still shown to students of architecture, physics and engineering.

There was only one casualty to the collapse. The man in the film running from his car was named Leonard Coatsworth. Mr. Coatsworth attempted to cross the bridge but abandoned his car and daughter's cocker spaniel Tubby. Tubby would not leave the car even when others attempted to rescue him and went down with the bridge.

Find out what else occurred on this day in science history.

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