Tacoma Narrows (USA) - 840 m bridge famous for its spectacular collapse
Location show on map
Tacoma, Washington, USA
Date of build
May 1940 - opening date
November 7, 1940 - the date of collapse
The structure of this bridge is a perfect example of a structure that is not very vulnerable to wind. The main span at 840 m was only 12 m wide. The lightweight bridge was too limp and its construction "caught" the wind. Tall and narrow towers formed a swirl of air around them. Already during the construction, the undulations of the whole construction were giving a hard time to the workers.
After opening in May 1940, the bridge became almost a tourist attraction due to the amazing sensations associated with walking on it. For this reason, Tacoma Narrows gained the reputation of "Galloping Gaiters". During stronger gusts of wind, the whole bridge danced to the accompaniment of the terrifying sound of metal elements rubbing against each other.
On the morning of November 7, 1940, the wind blowing at speeds of up to 67 km / h put the structure into its last dance. The structure of the platform fell into a twisting motion with a swivel of 8.5 m, with turning up to 45 degrees! Half an hour later, the first elements of the bridge began to peel off, and after an hour the entire deck collapsed.
This catastrophe gave architects a lot to think about. Since then, the platforms have been stiffened with trusses and narrow structures are not designed.
Since 1940, no disaster has been recorded in the suspension bridge caused by wind (excluding hurricanes or tornadoes). In 1952, a new bridge called Tacoma Narrows II was built on the site of the old one.
Official website: http://www.wsdot.wa.gov/TNBhistory/default.htm