MILLINIUM BRIDGE

Millenium Bridge

Millenium Bridge

History & Development

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). The bridge is owned and maintained by the Bridge House Estates, a charitable trust overseen by the City of London Corporation. Construction of the bridge began in 1998, with the opening in June 2000. 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 modifications eliminated the wobble entirely. It was reopened in 2002.

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. The nearest London Underground station is Mansion House.

Construction began in late 1998 with the main works beginning on 28 April 1999 by Monberg Thorsen and Sir Robert McAlpine.[1] 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.

Costs, Benefits And Risks

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 bridge's movements were caused by a 'positive feedback' ...