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,
Richmond Bridge, London Goose", the £3,500,000 yacht of National Car Parks founder Sir Donald Gosling, became wedged under the central arch of the bridge, eventually being freed at low tide the next day. The eighth Thames bridge to be built in what is now Greater London, Richmond Bridge is currently the oldest surviving bridge over the Thames in Greater London, and the oldest Thames bridge between the sea and Abingdon Bridge in Oxfordshire. Richmond Bridge was Grade I listed in 1952 and it is the only Georgian bridge over the Thames in London. Its bicentenary was celebrated on 7 May 1977; the commemoration