Raph's History Tips - The mystery behind The Millennium Bridge closing

The secrets revealed here:

The Millennium Bridge is the newest crossing to be built on the Thames; it is a suspension bridge with a unique design. Initially opened in June 2000, temporarily closed for almost two years, reopened in February 2002. It had an inauspicious start; the users experienced the 'wobbling' structure, which led it to be nicknamed the 'Wobbly' bridge by those living locally.

The Plan:

The plan was to create a thin and slim crossing, where there would be no structure obstructing the view. A regular suspension bridge would look like London's famous Albert Bridge, a modern take of that was created, a crossing with lateral suspensions, support from the sides rather than above.

The Problem:

During the early days of the crossing, large sways lasted for 30 seconds, paused for around 30 seconds, and repeated. The more people were walking on the bridge, the more it swayed. This was due to the force of the steps; the exertion of the lateral force caused the movement. With the cables running alongside, they had to be extremely tight; it is like a guitar string; the more it moves, the more it vibrates - resonance. The resonance matching the lateral force of the people caused the sway.

The Solution

Engineers installed shock absorbers called dampers to stop the swaying. When the bridge moved, these dampers would move, dissipating the energy. A solution that did not take the fantastic view away.

Want More?

You can visit London's historical monuments that the majority will miss out on; click here to learn more!