Mom would tell us stories about “Gallopin Gertie”, the Tacoma Narrows Bridge that collapsed in November of 1940. Mom grew up near there, in Bothell, Washington. She would tell us about her father driving the family out onto the bridge and parking. Then they would get out and back up far enough to see the car disappear behind the undulating bridge.
Eventually engineers figured out that the bridge’s spectacular wobble and eventual collapse were due to aereolastic flutter. (Fun new phrase, no?)
Then this morning I saw this bridge in Russia that was acting just like the Tacoma Narrows Bridge. From the BBC:
A 7km (four miles) long bridge over the Volga river in Volgograd, Russia, has been shut after the structure started to wobble.
Strong currents in the river caused by the flow of water from melting snow upstream apparently loosened one of the bridge’s vertical supports.
Officials are deciding whether to reopen the bridge.