Millennium Bridge (London) - Construction

Construction

Ordinarily bridges across the River Thames require an Act of Parliament. For this bridge that was avoided by the Port of London Authority granting a licence for the structure and the obtaining of planning permissions from the City of London and London Borough of Southwark. Construction began in late 1998 and the main works were started on 28 April 1999 by Monberg Thorsen and Sir Robert McAlpine. The bridge was completed at a cost of £18.2M (£2.2M over budget), primarily paid for by the Millennium Commission and the London Bridge Trust. It opened on 10 June 2000 (two months late).

Unexpected lateral vibration (resonant structural response) caused the bridge to be closed on 12 June for modifications. Attempts were made to limit the number of people crossing the bridge. This led to long queues but dampened neither public enthusiasm for what was something of a white-knuckle ride, nor the vibrations themselves. The closure of the bridge only two days after opening attracted public criticism of it as another high-profile British Millennium project suffered an embarrassing setback, akin to how many saw the Millennium Dome. The wobble was attributed to an under-researched phenomenon whereby pedestrians crossing a bridge that has a lateral sway have an unconscious tendency to match their footsteps to the sway, thereby exacerbating the sway. The tendency of a suspension bridge to sway when troops march over it in step was well known, which is why troops are required to break step when crossing such a bridge.

The bridge was temporarily closed on 18 January 2007, during the Kyrill storm due to strong winds and a risk of pedestrians being blown off the bridge.