Testing the dampers on the passerelle Simone de Beauvoir

[develishsmile]

what are they doing?

[eiffelover]

they are testing how the bridge wobbles. Every bridge has a natural frequency. Dampers are installed to damp out the vibrations. To test that the dampers work, the suthorities amass fifty odd people and get them to sway from side to side to the rythmn of a metronome. This gets the bridge moving. All of a sudden, they stop, and the time that it takes for the bridge to stop moving is measured. The shorter this time, the more effective the dampers.

[develishsmile]

that is interesting. I want to try