The Millennium Bridge, officially known as the London Millennium Footbridge, is a steel

suspension bridge A suspension bridge is a type of bridge in which the deck (bridge), deck is hung below suspension wire rope, cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridg ...

for pedestrians crossing the

River Thames The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, se ...

London London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...

, England, linking

Bankside Bankside is an area of London, England, within the London Borough of Southwark. Bankside is located on the southern bank of the River Thames, east of Charing Cross, running from a little west of Blackfriars Bridge to just a short distance befor ...

with the

City of London The City of London is a city, ceremonial county and local government district that contains the historic centre and constitutes, alongside Canary Wharf, the primary central business district (CBD) of London. It constituted most of London fr ...

. It is owned and maintained by

Bridge House Estates The Bridge House Estates is a charitable trust, originating in the late eleventh century and formally established by royal charter in 1282 by the City of London Corporation in London, England. It was originally established to maintain London Brid ...

, a charitable trust overseen by the

City of London Corporation The City of London Corporation, officially and legally the Mayor and Commonalty and Citizens of the City of London, is the municipal governing body of the City of London, the historic centre of London and the location of much of the United King ...

. Construction began in 1998, and it initially opened on 10 June 2000. Londoners nicknamed it the "Wobbly Bridge" after pedestrians experienced an alarming swaying motion on its opening day. The bridge was closed later that day and, after two days of limited access, it was closed again for almost two years so that modifications and repairs could be made to keep the bridge stable and stop the swaying motion. It reopened in February 2002. The bridge is located between

Southwark Bridge Southwark Bridge ( ) is an arch bridge in London, for traffic linking the district of Southwark and the City across the River Thames. Besides when others are closed for temporary repairs, it has the least traffic of the Thames bridges in Londo ...

and

Blackfriars Railway Bridge Blackfriars Railway Bridge is a railway bridge crossing the River Thames in London, between Blackfriars Bridge and the Millennium Bridge. First bridge There have been two structures with the name. The first bridge was opened in 1864 and was de ...

. Its southern end is near the

Globe Theatre The Globe Theatre was a theatre in London associated with William Shakespeare. It was built in 1599 by Shakespeare's playing company, the Lord Chamberlain's Men, on land owned by Thomas Brend and inherited by his son, Nicholas Brend, and gra ...

, the

Bankside Gallery Bankside Gallery is a public art gallery in Bankside, London, England. Opened by Queen Elizabeth II in 1980, Bankside is an educational charity, situated on the Thames Path just along from Tate Modern. The gallery is home to the Royal Watercolo ...

, and

Tate Modern Tate Modern is an art gallery located in London. It houses the United Kingdom's national collection of international modern and contemporary art, and forms part of the Tate group together with Tate Britain, Tate Liverpool and Tate St Ives. It is ...

, while its northern end is next to the

City of London School , established = , closed = , type = Public school Boys' independent day school , president = , head_label = Headmaster , head = Alan Bird , chair_label = Chair of Governors , chair = Ian Seaton , founder = John Carpenter , speciali ...

below

St Paul's Cathedral St Paul's Cathedral is an Anglican cathedral in London and is the seat of the Bishop of London. The cathedral serves as the mother church of the Diocese of London. It is on Ludgate Hill at the highest point of the City of London and is a Grad ...

. The bridge's alignment is such that a clear view (i.e. a "

terminating vista In urban design, a terminating vista is a building or monument that stands at the end or in the middle of a road, so that when one is looking up the street the view ends with the site. Function Terminating vistas are considered an important me ...

") of St Paul's south facade is presented from across the river, framed by the bridge supports.

Design

The design of the bridge was the subject of a

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...

organised in 1996 by

Southwark council Southwark London Borough Council is the local authority for the London Borough of Southwark in Greater London, England. It is a London borough council, one of 32 in the United Kingdom capital of London. History There have previously been a number ...

and

RIBA Competitions RIBA Competitions is the Royal Institute of British Architects' unit dedicated to organising architectural and other design-related competitions. Architectural design competitions are used by an organisation that plans to build a new building or re ...

. The winning entry was an innovative "blade of light" effort from

Arup Group Arup (officially Arup Group Limited) is a British multinational professional services firm headquartered in London which provides design, engineering, architecture, planning, and advisory services across every aspect of the built environment ...

Foster and Partners Foster + Partners is a British architectural, engineering, and integrated design practice founded in 1967 as Foster Associates by Norman Foster. It is the largest architectural firm in the UK with over 1,500 employees in 13 studios worldwide. ...

, and Sir

Anthony Caro Sir Anthony Alfred Caro (8 March 192423 October 2013) was an English abstract sculptor whose work is characterised by assemblages of metal using ' found' industrial objects. His style was of the modernist school, having worked with Henry Moor ...

. 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 , , and (north to south) with a total structure length of ; the aluminium deck is wide. The eight suspension cables are tensioned to pull with a force of 2,000

ton Ton is the name of any one of several units of measure. It has a long history and has acquired several meanings and uses. Mainly it describes units of weight. Confusion can arise because ''ton'' can mean * the long ton, which is 2,240 pounds ...

s against the piers set into each bank—enough to support a working load of 5,000 people on the bridge at a time.

Construction

Ordinarily, bridges across the River Thames require an Act of Parliament. For this bridge, that was avoided by the

Port of London Authority The Port of London Authority (PLA) is a self-funding public trust established on 31 March 1909 in accordance with the Port of London Act 1908 to govern the Port of London. Its responsibility extends over the Tideway of the River Thames and its ...

granting a licence for the structure, and the

and

London Borough of Southwark The London Borough of Southwark ( ) in South London forms part of Inner London and is connected by bridges across the River Thames to the City of London and London Borough of Tower Hamlets. It was created in 1965 when three smaller council areas ...

granting

planning permission Planning permission or developmental approval refers to the approval needed for construction or expansion (including significant renovation), and sometimes for demolition, in some jurisdictions. It is usually given in the form of a building perm ...

. Construction began in late 1998 and the main works were started on 28 April 1999 by

Monberg & Thorsen Monberg is a surname. List of people with the surname * Børge Monberg (1905–1990), Danish field hockey player * Jesper B. Monberg (born 1977), Danish speedway rider * Michael Monberg (born 1978), Danish politician * Terese Guinsatao Monber ...

and

Sir Robert McAlpine Sir Robert McAlpine Limited is a family-owned building and civil engineering company based in Hemel Hempstead, England. It carries out engineering and construction in the infrastructure, heritage, commercial, arena and stadium, healthcare, educa ...

. The eventual cost was £18.2 million (£2.2m over budget), primarily paid for by the

Millennium Commission The Millennium Commission, a United Kingdom public body, was set up to celebrate the turn of the millennium. It used funding raised through the UK National Lottery to assist communities in marking the close of the second millennium and celebra ...

and the London Bridge Trust.

Opening

The bridge opened on 10 June 2000, two months late. Unexpected lateral vibration due to resonant structural response caused the bridge to be closed on 12 June for modifications. Attempts had been made to limit the number of people crossing the bridge, which led to long queues but were ineffective to dampen the vibrations. Closure of the bridge only two days after opening attracted public criticism as another high-profile British Millennium project that suffered an embarrassing setback, akin to how many saw the

Millennium Dome The Millennium Dome was the original name of the large dome-shaped building on the Greenwich Peninsula in South East (London sub region), South East London, England, which housed a major exhibition celebrating the beginning of the third millenn ...

. Vibration 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, exacerbating it. The tendency of a suspension bridge to sway vertically when troops march over it in step was well known, which is why troops stop marching in stride together as a unit when crossing such a bridge. An example is London's Albert Bridge, which has a sign dating from 1873 warning

marching Marching refers to the organized, uniformed, steady walking forward in either rhythmic or route-step time; and, typically, it refers to overland movements on foot of military troops and units under field orders. Marching is often performed t ...

ranks of soldiers to break step while crossing.

Resonance

The bridge's movements were caused by a

positive feedback Positive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in the ...

phenomenon, known as ''synchronous lateral excitation''. The natural sway motion of people walking caused small sideways

oscillation Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...

s in the bridge, which in turn caused people on the bridge to sway in step, increasing the

amplitude The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of amplit ...

of the bridge oscillations and continually reinforcing the effect; the maximum sway was around 70mm. On the day of opening, the bridge was crossed by 90,000 people, with up to 2,000 on the bridge at a time.

Resonant Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscilla ...

vibrational modes due to vertical loads (such as trains, traffic or pedestrians) and wind loads are well understood in bridge design. In the case of the Millennium Bridge, because the lateral motion caused pedestrians to directly participate with the bridge, the vibrational modes had not been anticipated by the designers. When the bridge lurches to one side, the pedestrians must adjust to keep from falling over, and they all do this at the same time. The effect is similar to soldiers marching in lockstep, but horizontal instead of vertical. The risks of lateral vibration in lightweight bridges are well known. Any bridge with lateral frequency modes of less than 1.3 Hz, and sufficiently low mass, could witness the same phenomenon with sufficient pedestrian loading. The greater the number of people, the greater the amplitude of the vibrations. Other bridges which have seen similar problems are: *

Auckland Harbour Bridge The Auckland Harbour Bridge is an eight-lane motorway bridge over the Waitematā Harbour in Auckland, New Zealand. It joins St Marys Bay on the Auckland city side with Northcote on the North Shore side. It is part of State Highway 1 and the ...

, with a lateral frequency of 0.67 Hz during a 1975 demonstration * Birmingham NEC Link bridge, with a lateral frequency of 0.7 Hz

Mitigation

Engineers at Arup, the company that designed the bridge, conducted research into the unexpected oscillation which they called ''synchronous lateral excitation''. The first laboratory studies used pedestrians on moving platforms at the

University of Southampton , mottoeng = The Heights Yield to Endeavour , type = Public research university , established = 1862 – Hartley Institution1902 – Hartley University College1913 – Southampton University Coll ...

and

Imperial College London Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...

. Later in 2000, one span of the bridge was instrumented and tested with crowds of up to 275 people. They concluded that making the bridge stiffer, to move its resonant frequency out of the excitation range, was not feasible as it would greatly change its appearance. Instead, the resonance was controlled by retrofitting 37 viscous fluid dampers to dissipate energy. These include 17 chevron dampers – long V-shaped braces under the deck panels – to control lateral movement, 4 vertical to ground dampers to control lateral and vertical movements, and 16 pier dampers to control lateral and torsional movements. Additionally, 52

tuned mass damper A tuned mass damper (TMD), also known as a harmonic absorber or seismic damper, is a device mounted in structures to reduce mechanical vibrations, consisting of a mass mounted on one or more damped springs. Its oscillation frequency is tuned ...

s add inertia to control vertical movement. The work took from May 2001 to January 2002 and cost £5 million. After a period of testing, the bridge was reopened on 22 February 2002 and has not been subject to significant vibration since. In spite of the successful cure, the "wobbly bridge" (sometimes "wibbly-wobbly") epithet remains in common usage among Londoners. File:Millennium Bridge decking underside.jpg, Chevron dampers File:Bridge vert mode shock.jpg, Vertical to ground dampers File:Bridge_horiz_mode_shock.jpg, Pier dampers File:Moving End of Pier Damper of Millennium Bridge, London.jpg, Moving end of pier damper File:London Millennium Bridge - Damper beneath deck, north side - 240404.jpg, Tuned mass damper

Cable resonance

An artistic expression of the higher-frequency resonances within the cables of the bridge were explored by Bill Fontana's ''Harmonic Bridge'' exhibition at the Tate Modern in mid-2006. This used acoustic transducers placed at strategic locations on the cabling of the Millennium Bridge and the signals from those transducers were amplified and dynamically distributed throughout the Turbine Hall of the Tate by a programme which Fontana entered into the sound diffusion engine of the

Richmond Sound Design Richmond most often refers to: * Richmond, Virginia, the capital of Virginia, United States * Richmond, London, a part of London * Richmond, North Yorkshire, a town in England * Richmond, British Columbia, a city in Canada * Richmond, California, a ...

AudioBox.

Millennium Inclinator

A short inclined lift, known as the Millennium Inclinator, is next to the northern end of the Millennium Bridge. It was opened in December 2003 to allow pedestrians to surmount the steep slope (13.6°) of Peter's Hill from the riverside to the entrance to the Millennium Bridge without using the alternative flight of steps. The lower end of the lift is on Paul's Walk next to the

Thames The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...

, and the top end is further up Peter's Hill on the terrace which is level with the deck of the bridge. It was primarily installed for use by those who cannot easily manage the steep steps, such as people with disabilities and parents with push chairs. The lift carriage was originally powered by an electric

traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, elevators or electric multiple unit. Traction motors are used in electrically powered rail vehicles (ele ...

, manufactured in Italy by Maspero Elevatori, with a speed of and a maximum capacity of . However, by 2010 the City of London Planning and Transportation Committee decided that the level of service was unacceptable, because the inclinator was frequently out of service due to mechanical breakdowns and vandalism. So the Committee agreed it would be replaced at a cost of up to £750,000 in time for the

2012 Summer Paralympics The 2012 Summer Paralympics, branded as the London 2012 Paralympic Games, were an international multi-sport parasports event held from 29 August to 9 September 2012 in London, England, United Kingdom. They were the 14th Summer Paralympic Gam ...

. A major renovation project was undertaken in 2012, and the lift was reopened in time to be used by people attending the

Thames Diamond Jubilee Pageant The Thames Diamond Jubilee Pageant was a parade on 3 June 2012 of 670 boats on the Tideway of the River Thames in London as part of the celebrations of the Diamond Jubilee of Elizabeth II. The Queen, Prince Philip and other members of th ...

of 3 June 2012, which took place about a month before the

2012 Summer Olympics The 2012 Summer Olympics (officially the Games of the XXX Olympiad and also known as London 2012) was an international multi-sport event held from 27 July to 12 August 2012 in London, England, United Kingdom. The first event, the ...

. The new lift was manufactured by the company ''Hütter Aufzüge'' of

Glinde, Schleswig-Holstein Glinde () is a town in Germany in southern Schleswig-Holstein, approximately 7 km east of Hamburg. History The name Glinde was first mentioned in a document dated from March 25, 1229. In the document Graf Adolf IV. of Schauenburg and Holste ...

, Germany, a lift manufacturer which was taken over by the

Otis Elevator Company Otis Worldwide Corporation (trade name, branded as the Otis Elevator Company, its former legal name) is an American company that develops, manufactures and markets elevators, escalators, moving walkways, and related equipment. Based in Farming ...

in 2013. Installation was by Axis Elevators. Following a redevelopment of the area in 2021 the lift was closed and will be replaced by a platform lift.

In popular culture

Under the Millennium Bridge, London (geograph 4907090)

* The bridge is featured in the opening scenes of the film version of ''

Harry Potter and the Half-Blood Prince ''Harry Potter and the Half-Blood Prince'' is a fantasy novel written by British author J. K. Rowling and the sixth and penultimate novel in the ''Harry Potter'' series. Set during Harry Potter's sixth year at Hogwarts, the novel explores t ...

'', where the bridge collapses following an attack by

Death Eater The Death Eaters are characters featured in the ''Harry Potter'' series of novels and films. They are a radical group of wizards and witches, led by the dark wizard Lord Voldemort, who seek to purify the wizarding community by eliminating wiza ...

s. (although the book is set in 1996, two years before the bridge began construction). * The bridge appears in the 2014

Marvel Cinematic Universe The Marvel Cinematic Universe (MCU) is an American media franchise and shared universe centered on a series of superhero films produced by Marvel Studios. The films are based on characters that appear in American comic books published by ...

film ''

Guardians of the Galaxy The Guardians of the Galaxy is a fictional superhero team appearing in American comic books published by Marvel Comics. It may more specifically refer to: Comic book teams * Guardians of the Galaxy (1969 team), the original 31st-century team fr ...

'' during the climactic battle on

Xandar Xandar () is a fictional planet appearing in American comic books published by Marvel Comics. The planet is depicted as being in the Tranta system in the Andromeda Galaxy. It is best known as the home world of the Nova Corps, an intergalactic poli ...

. * The bridge appears in the anime adaptation of ''

The Ancient Magus' Bride is a Japanese manga series written and illustrated by Kore Yamazaki. It is serialized in Mag Garden's ''Monthly Comic Garden'' magazine and is licensed in North America by Seven Seas Entertainment. A three-part prequel anime Original vide ...

''. * The bridge appears in

BBC One BBC One is a British free-to-air public broadcast television network owned and operated by the BBC. It is the corporation's flagship network and is known for broadcasting mainstream programming, which includes BBC News television bulletins, p ...

's television film ''The 7:39''.

References

;Notes ;Bibliography * Reaney, Patricia. (6 November 2005). "Why the Millennium Bridge wobbled". ''

New Sunday Times The ''New Straits Times'' is an English-language newspaper published in Malaysia. It is Malaysia's oldest newspaper still in print (though not the first), having been founded as ''The Straits Times'' on 15 July 1845. It was relaunched as the ' ...

'', p. F20. * Strogatz, Steven. (2003). ''Sync: The Emerging Science of Spontaneous Order''. New York: Hyperion Books. (cloth) nd ed., Hyperion, 2004. (paper)

External links

*
Arup's Millennium Bridge site
*
PDF paper
from Arup, discussing the engineering and resonance of the bridge. *

from Taylor Devices Inc on the dampers retrofitted to the bridge * Information about th
GERB TMDs
retrofitted to the bridge.

* ttp://www-g.eng.cam.ac.uk/125/now/millennium_bridge.html A Cambridge University Engineering Department account of the Millennium Bridge problem.(January 2002)
Bing's Image of the Day for 2020-06-10
The Millennium Bridge is featured. *Archived a
Ghostarchive
and th
Wayback Machine
. A video of a descent and an ascent using the Millennium Inclinator. {{Authority control Tourist attractions in London Buildings and structures in the London Borough of Southwark Bridges in the City of London Suspension bridges in the United Kingdom Bridges completed in 2000 Buildings and structures celebrating the third millennium Foster and Partners buildings Pedestrian bridges across the River Thames Tourist attractions in the London Borough of Southwark Tourist attractions in the City of London 2000 establishments in England Pedestrian bridges in London Transport in the City of London Bridge light displays View of Tate Modern & Millennium Bridge at Sunset
View of Tate Modern & Millennium Bridge, London