Millennium Bridge, London people walking caused small sideways oscillations in the bridge, which in turn caused people on the bridge to sway in step, increasing the amplitude of the bridge oscillations and continually reinforcing the effect. On the day of opening, the bridge was crossed by 90,000 people, with up to 2,000 on the bridge at any one time. Resonant vibrational modes due to vertical loads (such as trains, traffic, pedestrians) and wind loads are well understood in bridge design. In the case of the Millennium Bridge, because the lateral motion caused the pedestrians loading the bridge to directly participate with the bridge,
London Bridge piece was meticulously numbered. The blocks were then shipped via the Panama Canal to California and trucked from Long Beach to Arizona. The bridge was reconstructed by Sundt Construction at Lake Havasu City, Arizona, and re-dedicated on 10 October 1971. The reconstruction of Rennie's London Bridge spans the Bridgewater Channel canal that leads from the Uptown area of Lake Havasu City and follows McCulloch Boulevard onto an island that has yet to be named. The London Bridge that was rebuilt at Lake Havasu City consists of a frame with stones from Rennie's London Bridge used as cladding. The cladding stones