The Millennium Bridge or “Wobbly Bridge” is an interesting story on how human induced motion caused the bridge to sway causing unsafe conditions for pedestrians. The bridge opened to the public on June 10, 2000 and measures 320 meters long and crosses the River Thames. On opening day, pedestrians walked across the bridge and, to their surprise, it began to sway. While some bridge sway is normal, the swaying got larger and larger until it was deemed unsafe. Luckily there were no serious injuries, but the bridge was immediately closed. Taylor Devices Inc. developed special Viscous Dampers for use on the bridge that were specified and designed to be used for mitigating the dynamic response of the bridge due to pedestrian traffic.

The dampers were originally designed and built for this nearly constant cycling over a period of more than 50 years, projected to total approximately 2 x 10⁹ (2 billion) cycles. Due to the fact that the results of the intermediate and principal inspections and testing show no signs of degradation, it is anticipated that the dampers will be able to meet this expected life time as anticipated.

Read the full case study here.