The Wibbly Wobbly Millennium Bridge in London скачать в хорошем качестве

The Wibbly Wobbly Millennium Bridge in London

The Wibbly Wobbly Millennium Bridge in London - This was filmed just after the bridge was opened to the public. As you can see it's a tad on the wobbly side. Such was the interest in the new bridge that when it opened to the public on 10 June 2000, an estimated 80,000 to 100,000 people crossed it. And then the problems began. Although the Millennium Bridge, like all bridges, was designed to cope with a degree of movement it soon became clear that things were going seriously awry as the deck swayed about like a drunken sailor. So the bridge was instantly renamed as 'The Wobbly Bridge', and after two days of random swaying, swinging, and oscillating wildly, the bridge was closed down by embarrassed engineers. Naturally, the press had a field day (in Britain we love failure!), questions were asked in Parliament and the public began to sense that perhaps another large white elephant had just landed on the shoreline of the Thames (the fiasco of the Dome was only a few miles downstream). Things didn't get much clearer when the engineers decided that the problem was apparently due to people walking the wrong way! claiming that the infamous wobble (or 'synchronous lateral excitation', as they put it) was due to the 'chance correlation of footsteps when we walk in a crowd'. This apparently - 'generated slight sideways movements of the bridge which made it more comfortable for people to walk in synchronization with the bridge movement'. In other words, once it started to sway people tried to counteract it, en masse, making the problem worse. After a prolonged series of tests, it was decided to adopt a passive damping system that would harness the movements of the structure to absorb energy. Two forms of passive damping were deployed: Viscous dampers and Tuned Mass Dampers. The Viscous dampers are located under the deck, around the piers and the south, to control the lateral motions and act much like shock absorbers. The tuned mass dampers are also located beneath the deck and reduce vertical movements. Acting like weights on strings, these inertial devices are tuned to a specific frequency and attached to discrete points on the structure. While work continued on the bridge, visitors were treated to the occasional sight of hundreds of paid volunteers walking over the bridge in army-type formations as the engineers battled to correct the swaying. After nearly two years of testing, the alterations have been deemed a success and the bridge finally reopened to the public in​ February 2002 - and the swaying was banished forever! This footage was filmed in June 2000