View source for Infinity Bridge

{{Short description|Footbridge over the River Tees, England}}
{{Use British English|date=September 2013}}
{{Use dmy dates|date=September 2024}}
{{Infobox bridge
 | bridge_name         = Infinity Bridge
 | native_name         =
 | image               = Infinity Bridge from the Tees Barrage-1200.jpg
 | image_size          = 250px
 | alt                 =
 | caption             = Infinity Bridge from the [[Tees Barrage]], named after the <math>\infty</math> symbol denoting [[infinity]]
 | official_name       = Infinity Bridge
 | carries             = Pedestrians and cyclists
 | crosses             = [[River Tees]], [[Teesdale Way]]
 | locale              = [[Stockton-on-Tees]], England
 | preceded            = [[Princess of Wales Bridge]]
 | followed            = [[Tees Barrage]]
 | owner               = Stockton-on-Tees Borough Council
 | maint               =
 | id                  = <!-- not applicable -->
 | winner              = [[Expedition Engineering]] and Spence Associates
 | contracted_designer = [[Expedition Engineering]]
 | design              = Asymmetric double tied-arch and suspended deck
 | material            = [[Weathering steel]], stainless steel and [[reinforced concrete]]
 | spans               = 2 river spans and 8 minor spans on approaches
 | pierswater          = 1
 | mainspan            = {{convert|120|m|ft|0}}
 | length              = {{convert|240|m|ft|0}}
 | width               = {{convert|5|m|ft|0}}
 | height              = {{convert|40|m|ft|0}}
 | load                =
 | clearance           =
 | below               = {{convert|8|m|ft|0}}
 | life                = 120 years
 | cost                = £15m
 | traffic             = 4,000 people/day anticipated
 | builder             = [[Balfour Beatty]]
 | fabricator          = [[Cleveland Bridge & Engineering Company]]
 | begin               = June 2007
 | complete            = December 2008
 | inaugurated         = 14 May 2009
 | open                = 16 May 2009
 | heritage            =
 | collapsed           =
 | closed              =
 | toll                = <!-- free -->
 | map_cue             =
 | map_image           =
 | map_text            =
 | map_width           =
 | coordinates         = {{Coord |54|33|53.26|N|1|17|57.09|W|display=inline,title}}
 | lat                 =
 | long                =
 | extra               =
}}
The '''Infinity Bridge''' is a public pedestrian and cycle [[footbridge]] across the [[River Tees]] in the [[borough of Stockton-on-Tees]] in northern England.
The bridge is situated one kilometre downriver of Stockton town centre, between the [[Princess of Wales Bridge]] and the [[Tees Barrage]]. It connects the [[Teesdale Business Park]] and the [[University of Durham]]'s [[Queen's Campus, Durham University|Queen's Campus]] in [[Thornaby-on-Tees]] on the south bank of the Tees with the [[Tees Valley Regeneration]]'s £320&nbsp;million North Shore development on the north bank.<ref name="BD">{{cite web |title=Infinity footbridge takes shape |url=http://www.bdonline.co.uk/news/infinity-footbridge-takes-shape/3129701.article |work=Building Design – The Architects' Website |date=11 December 2008 |access-date=14 March 2009 |archive-url=https://web.archive.org/web/20100627084721/http://www.bdonline.co.uk/news/infinity-footbridge-takes-shape/3129701.article |archive-date=27 June 2010 |url-status=live }}</ref><ref name="WYGgp">{{cite web|title=To Infinity and Beyond: Teesside Stockton Footbridge |url=http://www.wyg.com/media/pdf/case_studies/Teesside_Stockton_Footbridge.pdf |publisher=White Young Green |work=wyg.com |access-date=14 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110718123442/http://www.wyg.com/media/pdf/case_studies/Teesside_Stockton_Footbridge.pdf |archive-date=18 July 2011}}</ref>

Built at a cost of £15&nbsp;million<ref name="GazSteve">{{cite web|title=The latest addition to the River Tees skyline is taking shape |url=http://www.gazettelive.co.uk/news/teesside-and-tees-valley/stockton-focus/2008/02/18/the-latest-addition-to-the-river-tees-skyline-is-taking-shape-and-you-can-watch-its-progress-online-84229-20495519/ |first=Steve |last=Race |department=Gazette Live |work=Evening Gazette|date=18 February 2008 |access-date=14 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20080709042142/http://www.gazettelive.co.uk/news/teesside-and-tees-valley/stockton-focus/2008/02/18/the-latest-addition-to-the-river-tees-skyline-is-taking-shape-and-you-can-watch-its-progress-online-84229-20495519/ |archive-date=9 July 2008}}</ref><ref name="WYG-TSF">{{cite web|title=Case Study: Teesside Stockton Footbridge |url=http://www.wyg.com/5projects/projects.php?m=5&s=1&project=6 |publisher=White Young Green group |work=wyg.com |access-date=14 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110718123534/http://www.wyg.com/5projects/projects.php?m=5&s=1&project=6 |archive-date=18 July 2011}}</ref>
with funding from Stockton Borough Council, [[English Partnerships]] and its successor body the [[Homes and Communities Agency]], [[One NorthEast]], and the [[European Regional Development Fund]]<ref name="ONE">{{cite web|title=An infinitely fitting name |url=http://www.onenortheast.co.uk/page/news/article.cfm?articleid=3333&paneldisplay=true |publisher=One North East |work=onenortheast.co.uk |date=11 September 2008 |access-date=14 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110718063355/http://www.onenortheast.co.uk/page/news/article.cfm?articleid=3333&paneldisplay=true |archive-date=18 July 2011}}</ref>
the bridge is a major part of the North Shore Redevelopment Project undertaken by [[Tees Valley Regeneration]].

The bridge had the project title ''North Shore Footbridge'' before being given its official name ''Infinity Bridge'', chosen by a panel of representatives from the funding bodies, from a pool of names suggested by the public.<ref name="eGenda">{{cite web |title=Council Meeting – Stockton and Borough Council |url=http://www.egenda.stockton.gov.uk/aksstockton/users/public/admin/kab98.pl?cmte=&operation=DETAILS&odcname=odc576&phase=two |first=Mike |last=Robinson |publisher=Stockton-on-Tees Borough Council |date=1 September 2008 |work=stockton.gov.uk |access-date=14 March 2009 |archive-url=https://web.archive.org/web/20110723000326/http://www.egenda.stockton.gov.uk/aksstockton/users/public/admin/kab98.pl?cmte=&operation=DETAILS&odcname=odc576&phase=two |archive-date=23 July 2011 |url-status=dead }}</ref><ref name="NSF">{{cite web|title=The Footbridge at North Shore |url=http://www.northshorefootbridge.com/ |publisher=Balfour Beatty Civil Engineering and Stockton-on-Tees Borough Council |work=northshorefootbridge.com |access-date=14 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20081012151433/http://www.northshorefootbridge.com/ |archive-date=12 October 2008}}</ref>

The name derives from the [[infinity symbol]] (<math>\infty</math>) formed by the bridge and its reflection.<ref name="ONE"/>
[[File:Infinity Bridge in Stockton.jpg|left|thumb|The bridge illuminated after sunset, showing <math>\infty</math> reflection]]

== Design ==
Initial investigations for the [[footbridge]] were done by the White Young Green Group,<ref name="nebus">{{cite web |title=Firm looks to Infinity and beyond |url=http://www.nebusiness.co.uk/business-news/latest-business-news/2008/11/24/firm-looks-to-infinity-and-beyond-51140-22325950/ |work=Evening Gazette|date=24 November 2008 |access-date=14 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20111004062750/http://www.nebusiness.co.uk/business-news/latest-business-news/2008/11/24/firm-looks-to-infinity-and-beyond-51140-22325950/ |archive-date=4 October 2011 }}</ref>
who with English Partnerships produced a brief for an international [[architectural design competition]], organised with [[RIBA Competitions]]<ref name="WYGgp"/><ref name="nebus"/><ref name="Exped">{{cite web |title=Expedition Engineering |url=http://expedition.uk.com/projects/infinity-bridge-stockton-on-tees/ |publisher=Expedition Engineering |work=expedition-engineering.com |access-date=14 March 2009 |archive-url=https://web.archive.org/web/20150530073313/http://expedition.uk.com/projects/infinity-bridge-stockton-on-tees/ |archive-date=30 May 2015 |url-status=live }}</ref> and launched in April 2003.

The brief was for a "prestigious" and "iconic" "landmark" footbridge at North Shore Stockton, to cross the River Tees, which is {{convert|125|m|ft|0}} wide at that point.<ref name="Maskell">{{cite web |url=http://www.bath.ac.uk/ace/uploads/StudentProjects/Bridgeconference2009/Papers/MASKELL.pdf |title=A Critical Analysis of North Shore Footbridge, Stockton-on-Tees, UK |first=Daniel |last=Maskell |work=Proceedings of Bridge Engineering 2 Conference 2009 |publisher=bath.ac.uk |year=2009 |access-date=11 December 2009 |archive-url=https://web.archive.org/web/20110604072510/http://www.bath.ac.uk/ace/uploads/StudentProjects/Bridgeconference2009/Papers/MASKELL.pdf |archive-date=4 June 2011 |url-status=dead }}</ref>

More than 200 submissions were made to the [[RIBA Competitions|RIBA Competition]]; from these a shortlist of five was selected. The successful competition design was by Expedition Engineering and Spence Associates.<ref name="Maskell"/><ref name="BDN">{{cite web |title=Lift off for North Shore |work=Building Design News |access-date=19 January 2010 |url=http://www.buildingdesign-news2008.co.uk/2008/25-Tees-Valley-Regeneration-Regeneration,-planning-and-development-News-160608.asp |archive-url=https://web.archive.org/web/20100803022106/http://www.buildingdesign-news2008.co.uk/2008/25-Tees-Valley-Regeneration-Regeneration,-planning-and-development-News-160608.asp |archive-date=3 August 2010 |url-status=dead }}</ref><ref name="OotS">{{cite web |title=Overview of the Scheme |work=The Footbridge at North Shore |access-date=19 January 2010 |url=http://www.northshorefootbridge.com/overview-of-the-scheme |url-status=dead |archive-url=https://web.archive.org/web/20081120181437/http://www.northshorefootbridge.com/overview-of-the-scheme |archive-date=20 November 2008 }}</ref><ref name="TIF">{{cite web|title=The Infinity Footbridge |work=The Institution of Structural Engineers |access-date=16 October 2009 |url=http://www.istructe.org/activities_events_awards/Pages/SA09-InfinityFootbridge.aspx}}{{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}</ref>

The subsequent design was led by [[Expedition Engineering]] assisted by<ref name="BoTT">{{cite web |url=http://www.bridgesonthetyne.co.uk/infinity.html |title=Infinity Bridge, Stockton-on-Tees |work=Bridges on the Tyne |access-date=17 January 2010 |archive-url=https://web.archive.org/web/20101121012102/http://www.bridgesonthetyne.co.uk/infinity.html |archive-date=21 November 2010 |url-status=dead }}</ref>
Arup Materials, [[Balfour Beatty]] Regional Civil Engineering, [[Black and Veatch]], [[Bridon Ropes|Bridon]], [[University of Cambridge]], [[Cleveland Bridge & Engineering Company|Cleveland Bridge UK]],<ref>{{cite news|url=https://www.scottishconstructionnow.com/article/cleveland-bridge-the-british-bridges-built-by-innovation  |title=Cleveland Bridge: The British bridges built by innovation|date=16 April 2021|newspaper=Scottish Construction Now| access-date=18 September 2021}}</ref><ref name="DoorWay">{{cite web|url=http://www.door-way.co.uk/clevelandbridge/sectors.aspx |title=North Shore Footbridge |work=Cleveland |access-date=11 December 2009}}{{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}</ref>
Dorman Long Technology,<ref name="DoorWay"/>
[[Flint & Neill]],<ref name="FN">{{cite web|url=http://www.flintneill.com/storage/pdf-documents/new-data-sheets/FN%20Flyer%20-%20Infinity%20Bridge.pdf |title=Infinity Bridge, UK |publisher=Flint & Neill |work=flintneill.com |access-date=16 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110711011615/http://www.flintneill.com/storage/pdf-documents/new-data-sheets/FN%20Flyer%20-%20Infinity%20Bridge.pdf |archive-date=11 July 2011}}</ref>
Formfab, GCG, GERB, Imperial College,<ref name="Imperial">{{cite web |url=http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_9-11-2009-12-36-34 |title=Iconic bridge wins award with a little help from Imperial students |first=Colin |last=Smith |work=imperial.ac.uk |publisher=Imperial College |date=9 October 2009 |access-date=11 December 2009 |archive-url=https://web.archive.org/web/20110616061806/http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_9-11-2009-12-36-34 |archive-date=16 June 2011 |url-status=live }}</ref> [[RWDI]], Spence Associates, [[Speirs and Major Associates|Speirs & Major]], Stainton, and William Cook. White Young Green were project managers.<ref name="WYGgroup">{{cite web |url=http://www.wyg.com/news/iconic-bridge-wins-double-accolade |archive-url=https://web.archive.org/web/20160306235333/http://www.wyg.com/news/iconic-bridge-wins-double-accolade |url-status=dead |archive-date=6 March 2016 |title=Iconic Bridge Wins Double Accolade |publisher=WYG Group |work=wyg.com |date=20 May 2009}}</ref>

English Partnerships appointed [[Flint & Neill|Flint & Neill Limited]] to carry out a Category&nbsp;III independent check of the bridge design, including loading, wind tunnel testing, and investigation of failure modes. A number of aspects fall outside current standards.<!-- Elements of the bridge? or did the investigation go beyond current standards --><ref name="FN"/> The bridge has a 120-year design life.<ref name="Maskell"/>

=== Description ===

The bridge is a dual, [[tied arch bridge]] or [[bowstring bridge]]. It has a pair of continuous, differently-sized structural steel arches with suspended [[precast concrete]] decking<ref name="WYGgp"/><ref name="WYG-TSF"/><ref name="Exped"/> and one asymmetrically placed river [[Pier (architecture)|pier]]. The tapering arches with a trapezoidal box section are fabricated from [[weathering steel]] plate.<ref name="Maskell"/>

Each of the arches bifurcates within the spans to form a double rib over the river pier.<ref name="DLT">{{cite web |title=Northshore footbridge, UK |publisher=Dorman Long Technology |work=dormanlongtechnology.com |access-date=19 January 2010 |url=http://dormanlongtechnology.com/en/projects/Northshore.htm |archive-url=https://web.archive.org/web/20091105182942/http://www.dormanlongtechnology.com/en/projects/Northshore.htm |archive-date=5 November 2009 |url-status=live }}</ref><ref name="ACB">{{cite web|title=About Cleveland Bridge |work=Cleveland Process Designs Limited |access-date=19 January 2010 |url=http://www.door-way.co.uk/clevelandbridge/index.aspx}}{{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}</ref><ref name="DLTNS">{{cite web |author=DLT Consulting |title=Infinity footbridge, UK |work=Dorman Long Technology |access-date=12 February 2010 |url=http://dormanlong.com/en/projects/Northshore.htm |archive-url=https://web.archive.org/web/20110710144558/http://dormanlong.com/en/projects/Northshore.htm |archive-date=10 July 2011 |url-status=dead }}</ref>

A reflex piece between the two arches holds them together,<ref name="Maskell"/> making the two arches one continuous curve. No other bridge is known to have quite the same design.<ref name="WYGgp"/><ref name="WYG-TSF"/>

The offset river pier is to accommodate water sports and leisure craft to one side.<ref name="Clever">{{cite web |url=http://www.nce.co.uk/clever-step-over/1389114.article |title=Clever step over |first=Jessica |last=Rowson |work=New Civil Engineer |date=20 May 2008 |access-date=7 September 2009 |archive-url=https://web.archive.org/web/20111002145040/http://www.nce.co.uk/clever-step-over/1389114.article |archive-date=2 October 2011 |url-status=live }}</ref> The river pier is supported by an 11.5&nbsp;m square by 2.5&nbsp;m thick pile cap on sixteen 1&nbsp;m diameter hollow steel pipe piles.<ref name="Maskell"/> On the pile cap beneath the water line are four 3&nbsp;m cylindrical concrete legs, onto which are bolted and welded the four inclined grey steel legs visible above water.<ref name="Maskell"/><ref name="Clever"/><ref name="BB-Sept"/>
[[Riprap]] covers the river bed around the river pier for [[Bridge scour|scour]] protection<ref name="NSD">{{cite web |title=The Stockton-on-Tees Borough Council North Shore Development (North Shore Footbridge) Scheme 2006 |publisher=Office of Public Sector Information |access-date=19 January 2010 |url=http://www.legislation.gov.uk/uksi/2006/2503/pdfs/uksi_20062503_en.pdf |archive-url=https://web.archive.org/web/20101219035940/http://www.legislation.gov.uk/uksi/2006/2503/pdfs/uksi_20062503_en.pdf |archive-date=19 December 2010 |url-status=live }}</ref>
against the large flows when the [[Tees Barrage]] downstream discharges.

Each of the two concrete riverside piers are supported on four 500&nbsp;mm hollow steel piles and a pile cap.<ref name="Maskell"/>

The bridge as initially proposed was to have been some 272&nbsp;m long.<ref name="OPSI-2503">{{cite web |title=Statutory Instruments 2006 No. 2503 |url=http://www.legislation.gov.uk/uksi/2006/2503/pdfs/uksi_20062503_en.pdf |publisher=Office of Public Service Information |work=opsi.gov.uk |year=2006 |access-date=18 March 2010 |archive-url=https://web.archive.org/web/20101219035940/http://www.legislation.gov.uk/uksi/2006/2503/pdfs/uksi_20062503_en.pdf |archive-date=19 December 2010 |url-status=live }}</ref> It was originally designed with a northern approach 38&nbsp;m long and a southern approach of 54&nbsp;m;<ref name="BBCE">{{cite web|title=North Shore Footbridge |publisher=Balfour Beatty Civil Engineering Ltd |access-date=19 January 2010 |url=http://www.bbcel.co.uk/capabilities/bridges/540_north-shore-footbridge |url-status=dead |archive-url=https://web.archive.org/web/20110905041626/http://www.bbcel.co.uk/capabilities/bridges/540_north-shore-footbridge |archive-date=5 September 2011}}</ref>
however, the design of the north side of the bridge was later simplified and the bridge's northern approach shortened. The design of the southern approach is largely unaltered and has a staircase connecting it directly to the river frontage.<ref name="BBCE"/>

The bridge deck is 5&nbsp;m wide<ref name="NSD"/> and 4&nbsp;m between its custom-made handrails.<ref name="Maskell"/><ref name="OPSI">{{cite web |title=The Stockton-on-Tees Borough Council North Shore Development (North Shore Footbridge) Scheme 2006 Confirmation Instrument 2006 |publisher=Office of Public Sector Information |work=opsi.gov.uk |access-date=19 January 2010 |year=2006 |url=http://www.legislation.gov.uk/uksi/2006/2503/contents/made |archive-url=https://archive.today/20121223210532/http://www.legislation.gov.uk/uksi/2006/2503/contents/made |archive-date=23 December 2012 |url-status=live }}</ref><ref name="RealWire">{{cite web |title=Spectacular Infinity Bridge Is Regeneration Catalyst For Tees Valley |url=http://www.realwire.com/release_detail.asp?ReleaseID=12383 |work=realwire.com |date=15 May 2009 |access-date=16 May 2009 |archive-url=https://web.archive.org/web/20110719174519/http://www.realwire.com/release_detail.asp?ReleaseID=12383 |archive-date=19 July 2011 |url-status=live }}</ref>

The main arch of the bridge is 120&nbsp;m long, weighing 300&nbsp;tonnes, and 32&nbsp;m tall, with its top 40&nbsp;m above the Tees. The short arch is 60&nbsp;m long and 16&nbsp;m tall.<ref name="WYGgp"/><ref name="GazSteve"/><ref name="Exped"/> The hangers (droppers) are spaced 7.5&nbsp;m apart<ref name="FN"/> and are made from 30&nbsp;mm diameter, high-strength, locked-coil steel cable.<ref name="Maskell"/>

[[File:Infinity Bridge tuned mass damper on small arch-1632.jpg|150px|left|thumb|Single-tuned mass damper fitted to the underside of the concrete decking of the smaller arch of the bridge.]]

Four exposed, high-strength, post-tensioned, locked-coil steel-tie cables run alongside the deck and tie the bases of the arches together, pre-stressing the concrete deck sections.<ref name="FN"/>
The tie cables are 90&nbsp;mm diameter on the large arch and 65&nbsp;mm on the smaller.<ref name="Maskell"/>

The aggregate concrete deck sections are 7.5&nbsp;m long<ref name="Maskell"/> and down to 125&nbsp;mm thick in places, making it one of the thinnest bridge walking surfaces.<ref name="BPB">{{cite web|url=http://www.betterpublicbuilding.org.uk/finalists/2009/ |title=PM's Award Finalists 2009 |publisher=The Commission for Architecture and the Built Environment |work=betterpublicbuilding.org.uk |access-date=11 December 2009 |url-status=dead |archive-url=https://web.archive.org/web/20091207050250/http://www.betterpublicbuilding.org.uk/finalists/2009/ |archive-date=7 December 2009}}</ref>

The handrails and [[parapet]] are stainless steel<ref name="BBCE"/> while the [[balustrade]] is made from stainless steel wire.<ref name="NSFSoT">{{cite web |title=No bridge too far for Fabric8 |publisher=S3i Stainless Steel Solutions |access-date=19 January 2010 |url=http://www.s3i.co.uk/north_shore_footbridge.php |archive-url=https://web.archive.org/web/20100429025241/http://www.s3i.co.uk/north_shore_footbridge.php |archive-date=29 April 2010 |url-status=live }}</ref><ref name="fiiul">{{cite web|title=Wire balustrade installed on iconic footbridge in Stockton-on-Tees |work=finditinurbanliving.co.uk |access-date=19 January 2010 |date=18 November 2008 |url=http://www.finditinurbanliving.co.uk/ |url-status=dead |archive-url=https://web.archive.org/web/20090901122432/http://www.finditinurbanliving.co.uk/News_Article_Main.aspx?n_id=68c8121d-2e47-4760-b155-3ba3f11cd6f0 |archive-date=1 September 2009}}</ref>

To ensure any bridge oscillation is controlled, the deck is fitted to the underside with seven [[tuned mass damper]]s – one on the short arch, and six on the larger<ref name="Exped"/>
weighing 5&nbsp;tonnes in all.<ref name="Maskell"/> The mass dampers control horizontal as well as vertical oscillations<ref name="FN"/> – a feature only required on very slender bridges. There is provision for the addition of further dampers when the issue of maintenance arises.<ref name="Maskell"/>

The clearance (heading) below the decking on the navigable part of the river is 8&nbsp;m.<ref name="NSD"/>

{{clear|left}}

=== Illumination ===

A special feature is made of the way the bridge is lit at night.
This lighting scheme was designed by [[Speirs and Major Associates]]<ref name="Exped"/>
who also designed the lighting for the [[Burj Al-Arab]].
At night the bridge handrail and footway are lit with custom-made blue-and-white [[LED]] lighting built into the handrail that changes colour as pedestrians cross the bridge; sensors trigger a change from blue to white, leaving a 'comet's trail' in the person's wake.<ref name="metro">{{cite web|url=http://www.metropolismag.com/story/20091216/building-with-light |title=Building with Light |first=Jonathan |last=Glancy |work=metropolismag.com |date=16 December 2009 |access-date=17 January 2010 |url-status=dead |archive-url=https://web.archive.org/web/20091221004517/http://www.metropolismag.com/story/20091216/building-with-light |archive-date=21 December 2009}}</ref>
Attached to the steel cable ties are white metal-halide up-lighters to illuminate the white painted bridge arches, and blue LED down-lighters to illuminate the water and ground surfaces immediately below the deck.<ref name="metro"/>
At night from certain viewing angles when the river surface is flat calm, the twin arches together with their reflection in the river appear as an [[infinity]] symbol <math>\infty</math>, and it is this effect that inspired its name.

{{gallery |align=center
|File:Infinity_Bridge_first_south_pier-uplighters-900.jpg |Uplighters on the southern riverside pier illuminating the southern end of the arch
|File:Infinity Bridge-up down lighters-400.jpg |White metal halide up-lighters and blue LED down-lighters, attached to two steel tie cables running along either side of the bridge walkway
|File:Infinity_bridge_handrail_%26_deck_lighting-1024.jpg |Handrail and integral custom-made walkway lighting
}}

== Construction ==

[[File:North Shore Footbridge, Stockton-on-Tees, under construction (geograph 904211).jpg|250px|left|thumb|South bank of North Shore Footbridge during construction]]

The bridge was constructed in 18 months between June 2007 and December 2008<ref name="RealWire"/> by site constructor [[Balfour Beatty|Balfour Beatty Regional Civil Engineering]] and steel fabricator [[Cleveland Bridge & Engineering Company]] with White Young Green managing the whole project.

At the start of construction, a temporary jetty was built on the south bank to enable the building of a [[cofferdam]] for the safe construction of the central pier.<ref name="Maskell"/><ref name="BB-Sept">{{cite web|title=Balfour Beatty Update – September 2007 |url=http://www.northshorefootbridge.com/news/balfour-beatty-update-september-2007 |publisher=Balfour Beatty Civil Engineering and Stockton-on-Tees Borough Council |work=northshorefootbridge.com |access-date=29 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090105220537/http://www.northshorefootbridge.com/news/balfour-beatty-update-september-2007 |archive-date=5 January 2009}}</ref>
In April 2008, the supporting legs were added to the central pier.<ref name="BB-Jan">{{cite web|title=Balfour Beatty Update – January 2008 |url=http://www.northshorefootbridge.com/news/balfour-beatty-update-january-2008 |publisher=Balfour Beatty Civil Engineering and Stockton-on-Tees Borough Council |work=northshorefotbridge.com |access-date=29 March 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090106230042/http://www.northshorefootbridge.com/news/balfour-beatty-update-january-2008 |archive-date=6 January 2009}}</ref>
Steel falsework was constructed in the cofferdam by Dorman Long<ref name="BDN"/>
to support the ends of both incomplete arches as they cantilevered over the river during construction.<ref name="Maskell"/>
The first steel arch, made from four pieces of fabricated steel welded together,<ref name="BDN"/> was put in place in June 2008<ref name="BD"/> and was later used to stabilise the cantilevering lower portions of the main arch using a strand-jack and tie cable between the top of the small arch and the large arch and then to reduce sway stress during the progressive construction of the large arch.<ref name="DLT"/><ref name="DLTNS"/><ref name="DLT-IB">{{cite web |publisher=Dorman Long Technology |title=Infinity bridge, UK |access-date=19 January 2010 |work=dormanlong.com |url=http://www.dormanlongtechnology.com/?tab=2 |archive-url=https://web.archive.org/web/20150209190318/http://www.dormanlongtechnology.com/?tab=2 |archive-date=9 February 2015 |url-status=live }}</ref>
The final section of the main arch came in four pieces which were welded together on site<ref name="Maskell"/> and on 5&nbsp;September 2008 all 170&nbsp;tonnes of it was lifted into place by a 1,500-tonne mobile crane, the largest in the country.<ref name="BD"/><ref name="GazSteve"/>
The crane, a Gottwald AK680 owned by [[Sarens]]&nbsp;UK, is based in nearby Middlesbrough.
The crane is {{convert|80|m|ft|0}} high with a maximum of 1200&nbsp;tonnes of superlift, requires 45 transport wagons to move it,<ref name="GazSarens">{{cite web |title=UK’s biggest crane is huge lift for bridge |department=Gazette Live |work=Evening Gazette|access-date=18 January 2010 |date=4 September 2008 |url=http://www.gazettelive.co.uk/news/teesside-news/2008/09/04/uk-s-biggest-crane-is-huge-lift-for-bridge-84229-21673474/ |archive-url=https://web.archive.org/web/20081015012623/http://www.gazettelive.co.uk/news/teesside-news/2008/09/04/uk-s-biggest-crane-is-huge-lift-for-bridge-84229-21673474/ |archive-date=15 October 2008 |url-status=live }}</ref> and takes three days to set up using a 100-tonne crane.

The concrete deck panels were cast on site using three steel moulds in temporary sheds in a construction compound on the north bank of the river.<ref name="Maskell"/>
Using a short temporary jetty on the north bank the deck, panels were floated out on a small barge and jacked into position,<ref name="GazSteve"/> working progressively away from the river pier.
The concrete deck sections are held together by steel welds and adhesive.<ref name="Maskell"/>

The footbridge was completed on time and to budget in December 2008 with 530 workers and uses in total some 450 tonnes of [[Corus Group plc|Corus]] steel,<ref name="WYGgp"/>
1.5&nbsp;km of locked coil steel cable, 780 lights and 5,472 bolts,<ref name="WHATSON">{{cite web|title=Infinity Festival |url=http://www.chroniclelive.co.uk/entertainment-in-newcastle/ |first=Karen |last=McLauchlan |work=Chronicle Live |date=24 April 2009 |access-date=3 May 2009 |url-status=dead |archive-url=https://web.archive.org/web/20100527223308/http://www.chroniclelive.co.uk/entertainment-in-newcastle/ |archive-date=27 May 2010}}</ref> and weighs 1040 tons.
Almost all labour, materials and components were sourced regionally.

== Operation ==

The bridge was officially opened on 14 May 2009 with celebrations that included a sound, light and animation show, [[parkour]] [[Parkour#Derivative terminologies and disciplines|freerunners]] who climbed the bridge arches with flares, and a specially composed music track and synchronised pyrotechnics from the bridge itself with big screens for the estimated audience of 20,000 spectators along the banks.<ref name="IBOC">{{cite web|title=Infinity Bridge Opening Celebrations |work=Visit England |access-date=13 March 2009 |url=http://www.visitengland.com/ee/Events/Stockton-On-Tees/Show-or-Display-Ceremony-/833996/Infinity-Bridge-Opening-Celebrations.htm}}{{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}; {{cite web |title=Infinity Bridge Opening Event, Stockton |work=News Guardian |access-date=20 January 2013 |url=http://www.newsguardian.co.uk/news/local/cultural-programme-2009-unveiled-1-1596669 |archive-url=https://web.archive.org/web/20120807091149/http://www.newsguardian.co.uk/news/local/cultural-programme-2009-unveiled-1-1596669 |archive-date=7 August 2012 |url-status=live }}</ref>
The bridge was opened to the public two days later.<ref name="TVR">{{cite web|title=Awards for Infinity Bridge |url=http://www.teesvalleyunlimited-investment.co.uk/news/story/storyid=129 |publisher=Tees Valley Regeneration |work=teesvalleyregeneration.co.uk |access-date=16 May 2009 |url-status=dead |archive-url=https://web.archive.org/web/20110809072504/http://www.teesvalleyunlimited-investment.co.uk/news/story/storyid%3D129 |archive-date=9 August 2011 }}</ref>
Foot traffic is anticipated to rise to some four thousand people a day as the North Shore site develops.<ref name="WYGgp"/><ref name="GazSteve"/><ref name="WYG-TSF"/>

== Awards ==

The bridge won the [[Institution of Structural Engineers]]' Supreme [[Structural Awards|Award]] for Structural Excellence 2009,<ref name="NCE">{{cite web |url=http://www.nce.co.uk/news/structures/infinity-bridge-scoops-structural-awards/5209351.article |title=Infinity bridge scoops Structural Awards |work=New Civil Engineer |date=12 October 2009 |access-date=5 January 2009 |archive-url=https://web.archive.org/web/20120427081038/http://www.nce.co.uk/news/structures/infinity-bridge-scoops-structural-awards/5209351.article |archive-date=27 April 2012 |url-status=live }}</ref>
the premier structural engineering award in the UK.
It also won in its own category of Pedestrian Bridges.
The other awards the bridge has won include the [[British Constructional Steelwork Association|British Constructional Steelwork Association's]] Structural Steel Design Award 2010,<ref name="CCSDA">{{cite web|title=Corus Structural Steel Design Award 2010 |work=corusconstruction.com |access-date=5 November 2010 |year=2010 |url=http://www.corusconstruction.com/en/news_and_events/awards/structural_steel_design_award/2010/#44018 |url-status=dead |archive-url=https://web.archive.org/web/20101122081023/http://www.corusconstruction.com/en/news_and_events/awards/structural_steel_design_award/2010/ |archive-date=22 November 2010}}</ref>
the [[Concrete Society]] Civil Engineering Award 2009,<ref name="cecw">{{cite web|title=Civil Engineering Category Winner |work=The Concrete Society |access-date=5 November 2010 |url=http://www.concrete.org.uk/awards/awards2009/awards_civil.asp |url-status=dead |archive-url=https://web.archive.org/web/20110719151750/http://www.concrete.org.uk/awards/awards2009/awards_civil.asp |archive-date=19 July 2011}}</ref>
the ''ICE Robert Stephenson Award'' 2009, the ''North East Constructing Excellence Awards'' 'Project of the Year',<ref name="TVR"/> and the ''Green Apple Award'' for the environment.<ref name="TGO">{{cite web|title=Green Apple Awards 2009 for the Built Environment and Architectural Heritage |work=The Green Organisation |access-date=11 December 2009 |url=http://www.thegreenorganisation.info/GABEA.asp |url-status=dead |archive-url=https://web.archive.org/web/20090215020100/http://www.thegreenorganisation.info/GABEA.asp |archive-date=15 February 2009}}</ref>

== Photo gallery ==

{{gallery |align=center
|Image:Infinity_bridge_small-south_arch.jpg |The smaller south arch
|Image:Infinity_bridge_big-north_arch.jpg |The larger north arch
|Image:Infinity_bridge_central_pier%26_small_arch-2.jpg |Central pier and large arch
|Image:Infinity_bridge_central_pier.jpg |The central pier
|Image:Infinity Bridge first south pier from north side-1088.jpg |The southern riverside concrete pier with reaction plate viewed from the north side
|Image:Infinity Bridge first south pier-1088.jpg |The south riverside pier and concrete decking
|Image:Infinity_bridge_seven_south_piers.jpg |The seven south piers and approaches
|Image:Infinity_bridge_north_pier.jpg |The north riverside pier and abutment
|Image:Infinity_bridge_cable_connectors-2.jpg |An angled dropper, deck support and bowstring cables
|Image:Infinity_bridge_cable_ties_north_bank.jpg |Tie cable tensioning clamps on the north bank
|Image:Infinity_bridge_info_board.jpg |Infinity Bridge information board
|Image:Infinity Bridge from River Tees Watersports Centre-1632.jpg |Infinity Bridge from the River Tees Watersports Centre
}}

== References ==

{{reflist}}

== External links ==

{{commons category|Infinity Bridge}}
* {{Structurae|id=20010615 |title=Infinity Bridge}}
* [http://www.bridgesonthetyne.co.uk/infinity.html Infinity Bridge] on [http://www.bridgesonthetyne.co.uk/ Bridges on the Tyne] website
* Bridge design analysis, review and critique: [http://www.bath.ac.uk/ace/uploads/StudentProjects/Bridgeconference2009/Papers/MASKELL.pdf A Critical Analysis of North Shore Footbridge] {{Webarchive|url=https://web.archive.org/web/20110604072510/http://www.bath.ac.uk/ace/uploads/StudentProjects/Bridgeconference2009/Papers/MASKELL.pdf |date=4 June 2011 }}
* Construction video: [http://news.bbc.co.uk/1/hi/england/7610202.stm BBC] {{Webarchive|url=https://web.archive.org/web/20090220125343/http://news.bbc.co.uk/1/hi/england/7610202.stm |date=20 February 2009 }}
* Construction animation: [http://www.oasys-software.com/casestudies/casestudy/infinity_bridge Oasys]
* Images: [http://dormanlong.com/en/projects/Northshore.htm Dorman Long Technology], [https://www.flickr.com/search/?s=int&q=Infinity+Bridge+Stockton&m=text Flickr].
* Bridge model: [http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_9-11-2009-12-36-34 Imperial College].

{{Navboxes|list1 =

{{Geographic location
|Northwest =
|North =
|Northeast = [[Portrack]]
|West = [[Princess of Wales Bridge]],<br/>[[Stockton-on-Tees]] town centre
|Centre = {{center|Infinity Bridge<br/>over the [[River Tees]]}}
|East = [[Tees Barrage]],<br/>[[Teesside White Water Course|Tees Barrage International White Water Course]]
|Southwest = [[Teesdale Business Park]]
|South = [[Teesdale Way]],<br/>[[Teesdale Business Park]],<br/>[[Thornaby railway station]]
|Southeast =     }}

{{Crossings navbox
|structure  = [[:Category:Crossings of the River Tees|Crossings]]
|place      = [[River Tees]]
|bridge     = Infinity Bridge
|upstream   = [[Princess of Wales Bridge]]<br/>(Diana Bridge)
|downstream = [[Tees Barrage]]    }}

{{stockton}}

{{IStructE Supreme Award laureates}}   }}

[[Category:2008 establishments in England]]
[[Category:Crossings of the River Tees]]
[[Category:Bridges completed in 2008]]
[[Category:Pedestrian bridges in England]]
[[Category:Tied arch bridges]]
[[Category:Bridges in County Durham]]
[[Category:Bridges in North Yorkshire]]
[[Category:Buildings and structures in Stockton-on-Tees]]
[[Category:Places in the Tees Valley]]
[[Category:Arch bridges in the United Kingdom]]