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 Richmond Bridge, London Richmond Bridge is an 18th-century stone arch bridge that crosses the River Thames at Richmond, connecting the two halves of the present-day London Borough of Richmond upon Thames. It was designed by James Paine and Kenton Couse. The bridge, which is a Grade I listed, was built between 1774 and 1777, as a replacement for a ferry crossing which connected Richmond town centre on the east bank with its neighbouring district of East Twickenham to the west. Its construction was privately funded by a tontine scheme, for which tolls were charged until 1859. Because the river meanders