Millennium Bridge

BRIDGE
Millennium Bridge
Carries	Pedestrians
Maintained by
Design	Suspension Bridge
Total Length	370 m
Clearance Below
Opening Date	10 June 2000

The London Millennium Footbridge is a pedestrian-only steel suspension bridge crossing the River Thames in London, England, linking Bankside with the City. It is located between Southwark Bridge (downstream) and Blackfriars Bridge (upstream). With construction beginning in 1998, it is owned and maintained by the Bridge House Estates a charitable trust overseen by the City of London Corporation.

Londoners nicknamed the bridge the Wobbly Bridge after crowds of pedestrians felt an unexpected swaying motion on the first two days after the bridge opened. The bridge was closed and modified, and further modifications eliminated the "wobble" entirely.

The southern end of the bridge is near Globe Theatre, the Bankside Gallery and Tate Modern, the north end next to the City of London School below St Paul's Cathedral. The bridge alignment is such that a clear view of St Paul's south facade is presented from across the river, framed by the bridge supports, thus providing a scenic view of the cathedral.

Design

The design of the bridge was the subject of a competition organised in 1996 by Southwark council. The winning entry was an innovative "blade of light" effort from Arup, Foster and Partners and Sir Anthony Caro. Due to height restrictions, and to improve the view, the bridge's suspension design had the supporting cables below the deck level, giving a very shallow profile. The bridge has two river piers and is made of three main sections of 81 metres (266 ft), 144 metres (472 ft) and 108 metres (354 ft) (North to South) with a total structure length of 325 metres (1,066 ft); the aluminium deck is 4 metres (13 ft) wide. The eight suspension cables are tensioned to pull with a force of 2,000 tons against the piers set into each bank — enough to support a working load of 5,000 people on the bridge at one time.

The Millennium Footbridge with St Paul's Cathedral in the background

Construction

The bridge from St Paul's Cathedral

Construction began in late 1998 with the main works beginning 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) and opened on 10 June 2000 (2 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 three days after opening attracted public criticism, as another high-profile British millennium project suffered an embarrassing setback, akin to how many saw the Millennium Dome.

Further modifications to the bridge successfully eliminated the "wobble," which has not recurred since the bridge reopened in February 2002.

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.

Cependant il a dû être fermé au public deux jours plus tard, en raison d'un phénomène de résonance, le pont oscillant latéralement de façon imprévue. Ce jour-là, une marche caritative devant traverser le pont attira beaucoup de monde. Les mouvements de balancement furent provoqués par le grand nombre de piétons (90 000 personnes le premier jour avec jusqu'à 2 000 personnes en même temps sur le pont). Les premières vibrations encourageaient et parfois obligeaient les piétons à marcher au rythme du balancement, ce qui accentua les oscillations, même en début de journée lorsque le pont était relativement peu chargé.

Ce mouvement de balancement lui a valu le surnom de Wobbly Bridge (pont bancal). Les mesures prises pour limiter le nombre de personnes traversant le pont ont entraîné de longues files d'attente, mais n'ont atténué ni l'enthousiasme du public pour ce manège qui décoiffe, ni les vibrations elles-mêmes. La fermeture du pont après seulement trois jours d'ouverture a été sévèrement critiquée par le public, qui associait ce retard à celui dont avait souffert le Dôme du Millenium.

In Popular Culture

• The Millenium Bridge will appear in the upcoming film, Harry Potter and the Half-Blood Prince, which involves the bridge collapsing.