"London Bridge is falling down," repeats the well-known nursery rhyme. Indeed, that famous bridge over England's Thames River has been rebuilt several times over the centuries to correct engineering deficiencies and to support increased traffic. What's the newest bridge over the river, and why has it recently been declared unstable?
The Millennium Bridge across London's Thames River is the first new river crossing constructed since the Tower Bridge was opened in 1894. The new bridge is a pedestrian bridge, on which no vehicles are allowed. In order not to block the view of nearby St. Paul's Cathedral, this suspension bridge was given a unique design.
The suspension cables fan out sideways from the concrete and steel piers, instead of upward as is common with suspension bridges like the Golden Gate Bridge in San Francisco, California.
The bridge opened in June 2000. It was closed just days later due to severe swaying. The combination of wind and heavy foot traffic made the bridge sway side-to-side by as much as 20 cm (almost 8 inches), sending pedestrians grabbing for the handrails.
Although there is no danger of the bridge collapsing, it remains closed. Engineers are currently preparing a report that will help determine the future of the Millennium Bridge.