Infinity Bridge
Encyclopedia
The Infinity Bridge is a public pedestrian and cycle footbridge
across the River Tees
in the borough of Stockton-on-Tees in the north east of England
. The bridge is situated one kilometre downriver of Stockton town centre, between the Princess of Wales Bridge
and the Tees Barrage
and it links the Teesdale Business Park
and the University of Durham's Queen's Campus in Thornaby-on-Tees
on the south bank of the Tees with the Tees Valley Regeneration's £320 million North Shore development on the north bank.
Built at a cost of £15 million 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
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 made from the funding bodies, using names suggested by the public. The name derives from the infinity symbol formed by the bridge and its reflection.
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 125 m wide at that point.
There were more than 200 entries to the competition but this was slimmed down to a shortlist of five. The successful competition design was by Expedition Engineering and architect Spence Associates.
The subsequent design was led by Expedition Engineering
assisted by Arup Materials, Balfour Beatty Regional Civil Engineering, Black and Veatch, Bridon
, Cambridge University, Cleveland Bridge UK
, Dorman Long Technology, Flint & Neill, Formfab, GCG, GERB, Imperial College, RWDI
, Spence Associates, Speirs & Major
, Stainton, and William Cook while White Young Green were project managers.
English Partnerships appointed Flint & Neill Limited to carry out a category III independent check of the bridge design including loading, wind tunnel testing, and investigation of failure modes, a number of aspects of which fall outside current standards. The bridge has a 120 year design life.
or bowstring bridge. It has a pair of continuous, differently-sized structural steel arches with suspended precast concrete
decking and one asymmetrically placed river pier
. The tapering arches are fabricated from weathering steel plate box sections. The arches both bifurcate within the spans to form a double rib over the river pier. A reflex piece between the two arches holds them together making the two arches one continuous curve. No other bridge is known to have quite the same design.
The offset river pier is to accommodate water sports and leisure craft to one side. The river pier is supported by a 11.5 m square by 2.5 m thick pile cap on sixteen 1 m diameter hollow steel pipe piles. On the pile cap beneath the water line are four 3 m cylindrical concrete legs onto which are bolted and welded the four inclined gray steel legs visible above water. Riprap
covers the river bed around the river pier for scour
protection against the large flows when the Tees Barrage
downstream discharges. Each of the two concrete riverside piers are supported on four 500 mm hollow steel piles and a pile cap.
The bridge as initially proposed was to have been some 272 m long. It was originally designed with a northern approach 38 m long and a southern approach of 54 m 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. The bridge deck is 5 m wide and 4 m between its handrails. The main arch of the bridge is 120 m long, weighing 300 tonnes, 32 m tall with its top 40 m above the Tees and the short arch is 60 m long and 16 m tall. The hangers (droppers) are spaced 7.5 m apart and are made from 30 mm diameter high strength locked coil steel cable.
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. The tie cables are 90 mm diameter on the large arch and 65 mm on the smaller. The aggregate concrete deck sections are 7.5 m long and down to 125 mm thick in places, making it one of the thinnest bridge walking surfaces. The handrails and parapet
are stainless steel while the balustrade is made from stainless steel wire. 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 weighing 5 tonnes in all. The mass dampers control horizontal as well as vertical oscillations - a feature only required on very slender bridges. There is provision for the addition of further dampers when the issue of maintenance arises. The clearance (heading) below the decking on the navigable part of the river is 8 m.
who also designed the lighting for the Burj Al-Arab
. At night the bridge handrail and footway are lit with designer blue and white LED
lighting built into the handrail that changes colour as users cross. 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. 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 ∞, and it is this effect that inspired its name.
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. In April 2008 the supporting legs were added to the central pier. Steel falsework was constructed in the cofferdam by Dorman Long to support the ends of both incomplete arches as they cantilevered over the river during construction. The first steel arch made from four pieces of fabricated steel welded together, was put in place in June 2008 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 its progressive construction of the large arch.
The final section of the main arch came in four pieces which were welded together on site and on 5 September 2008 all 170 tonnes of it was lifted into place by a 1,500 tonne mobile crane, the largest in the country. The crane, a Gottwald AK680 owned by Sarens UK is based in nearby Middlesbrough. The crane is 80 metres (262 ft) high with a maximum of 1200 tonnes of superlift, requires 45 transport wagons to move it, 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. Using a short temporary jetty on the north bank the deck panels were floated out on a small barge and jacked into position working progressively away from the river pier. The concrete deck sections are held together by steel welds and adhesive.
The footbridge was completed on time and to budget in December 2008 with 530 workers and uses in total some 450 tonnes of Corus steel, 1.5 km of locked coil steel cable, 780 lights, 5,472 bolts and weighs 1040 tons. Almost all labour, materials and components were sourced locally.
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. The bridge was opened to the public two days later. Foot traffic is anticipated to rise to some four thousand people a day as the North Shore site develops.
' Supreme Award
for Structural Excellence 2009, 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 Structural Steel Design Award 2010, the Concrete Society Civil Engineering Award 2009, the ICE Robert Stephenson Award 2009, the North East Constructing Excellence Awards 'Project of the Year', and the Green Apple Award for the environment.
Other regional bridge developments
Footbridge
A footbridge or pedestrian bridge is a bridge designed for pedestrians and in some cases cyclists, animal traffic and horse riders, rather than vehicular traffic. Footbridges complement the landscape and can be used decoratively to visually link two distinct areas or to signal a transaction...
across the River Tees
River Tees
The River Tees is in Northern England. It rises on the eastern slope of Cross Fell in the North Pennines, and flows eastwards for 85 miles to reach the North Sea between Hartlepool and Redcar.-Geography:...
in the borough of Stockton-on-Tees in the north east of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. The bridge is situated one kilometre downriver of Stockton town centre, between the Princess of Wales Bridge
Princess of Wales Bridge
The Princess of Wales Bridge is a dual carriageway road bridge carrying the Teesdale Boulevard across the River Tees in Stockton-on-Tees in the Northeast of England. The bridge links on the south bank of the river, Teesdale Business Park in Thornaby-on-Tees to the north bank at the north end of...
and the Tees Barrage
Tees Barrage
The Tees Barrage is a barrage across the River Tees just upriver of Blue House Point in the borough of Stockton-on-Tees in North East of England and is used to control the flow of the river, preventing flooding and the effects of tidal change....
and it links the Teesdale Business Park
Teesdale Business Park
Teesdale Business Park is a major business park on the former site of Head Wrightsons' Teesdale works in Thornaby-on-Tees in the borough of Stockton-on-Tees, England. The park was redeveloped by the Teesside Development Corporation. The area is immediately north of Thornaby railway station,...
and the University of Durham's Queen's Campus in Thornaby-on-Tees
Thornaby-on-Tees
Thornaby-on-Tees is a town and civil parish within the Borough of Stockton-on-Tees, in the ceremonial county of North Yorkshire, England. It is on the south bank of the River Tees, three miles southeast of Stockton-on-Tees, and four miles southwest of Middlesbrough town centre and has a...
on the south bank of the Tees with the Tees Valley Regeneration's £320 million North Shore development on the north bank.
Built at a cost of £15 million with funding from Stockton Borough Council, English Partnerships
English Partnerships
English Partnerships was the national regeneration agency for England, performing a similar role on a national level to that fulfilled by Regional Development Agencies on a regional level...
and its successor body the Homes and Communities Agency
Homes and Communities Agency
The Homes and Communities Agency is the non-departmental public body that funds new affordable housing in England. It was established by the Housing and Regeneration Act 2008 as one of the successor bodies to the Housing Corporation, and became operational on 1 December 2008.-Background:On 17...
, One NorthEast
One NorthEast
One North East is the regional development agency for the North East England region.-History:It was established in April 1999. The North East receives a lot of government aid for regeneration....
, and the European Regional Development Fund
European Regional Development Fund
The European Regional Development Fund is a fund allocated by the European Union.-History:During the 1960s, the European Commission occasionally tried to establish a regional fund. Only Italy ever supported this, however, and nothing came of it. Britain made it an issue for their accession in...
the bridge is a major part of the North Shore Redevelopment Project undertaken by Tees Valley Regeneration
Tees Valley Regeneration
Tees Valley Regeneration was an urban regeneration company covering the Tees Valley area of North East England and at one time was the largest urban development agency in England...
.
The bridge had the project title North Shore Footbridge before being given its official name Infinity Bridge, chosen by a panel made from the funding bodies, using names suggested by the public. The name derives from the infinity symbol formed by the bridge and its reflection.
Design
Initial investigations for the footbridge were done by the White Young Green Group who with English Partnerships produced a brief for an international design competition organised with the RIBARoyal Institute of British Architects
The Royal Institute of British Architects is a professional body for architects primarily in the United Kingdom, but also internationally.-History:...
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 125 m wide at that point.
There were more than 200 entries to the competition but this was slimmed down to a shortlist of five. The successful competition design was by Expedition Engineering and architect Spence Associates.
The subsequent design was led by Expedition Engineering
Expedition Engineering
Expedition Engineering is a London based consulting firm, delivering structural engineering services.-History:Expedition Engineering was founded in 1999 by Professor Chris Wise and Seán Walsh, both former employees at Arup.On 2 October 2008, Expedition's ownership was restructured, passing to an...
assisted by Arup Materials, Balfour Beatty Regional Civil Engineering, Black and Veatch, Bridon
FKI
FKI is a British major engineering and manufacturing company headquartered in Loughborough, Leicestershire. For many years listed on the London Stock Exchange and a constituent of the FTSE 250 Index, but it was taken private by buyout firm Melrose in July 2008....
, Cambridge University, Cleveland Bridge UK
Cleveland Bridge & Engineering Company
The Cleveland Bridge & Engineering Company is a renowned bridge building and structural engineering company based in Darlington, England. It has been involved in many major projects including the Victoria Falls Bridge and the Humber Bridge.-History:...
, Dorman Long Technology, Flint & Neill, Formfab, GCG, GERB, Imperial College, RWDI
RWDI
Wind Engineering Firm Established in 1972, Rowan Williams Davies & Irwin Inc. is a specialty consulting engineering firm. The RWDI group of companies has over 275 employees with offices in Canada, USA, United Kingdom, India and the Middle East....
, Spence Associates, Speirs & Major
Speirs and Major Associates
Speirs and Major Associates is a UK lighting design practice founded by Jonathan Speirs and Mark Major in 1992. The practice is particularly noted for its illumination of prominent buildings, including Barajas International Airport, 30 St Mary Axe , the Millennium Dome and the interior of St. Pauls...
, Stainton, and William Cook while White Young Green were project managers.
English Partnerships appointed Flint & Neill Limited to carry out a category III independent check of the bridge design including loading, wind tunnel testing, and investigation of failure modes, a number of aspects of which fall outside current standards. The bridge has a 120 year design life.
Description
The bridge is a dual, tied arch bridgeTied arch bridge
A tied-arch bridge is an arch bridge in which the outward-directed horizontal forces of the arch, or top chord, are borne as tension by the bottom chord , rather than by the ground or the bridge foundations...
or bowstring bridge. It has a pair of continuous, differently-sized structural steel arches with suspended precast concrete
Precast concrete
By producing precast concrete in a controlled environment , the precast concrete is afforded the opportunity to properly cure and be closely monitored by plant employees. Utilizing a Precast Concrete system offers many potential advantages over site casting of concrete...
decking and one asymmetrically placed river pier
Pier (architecture)
In architecture, a pier is an upright support for a superstructure, such as an arch or bridge. Sections of wall between openings function as piers. The simplest cross section of the pier is square, or rectangular, although other shapes are also common, such as the richly articulated piers of Donato...
. The tapering arches are fabricated from weathering steel plate box sections. The arches both bifurcate within the spans to form a double rib over the river pier. A reflex piece between the two arches holds them together making the two arches one continuous curve. No other bridge is known to have quite the same design.
The offset river pier is to accommodate water sports and leisure craft to one side. The river pier is supported by a 11.5 m square by 2.5 m thick pile cap on sixteen 1 m diameter hollow steel pipe piles. On the pile cap beneath the water line are four 3 m cylindrical concrete legs onto which are bolted and welded the four inclined gray steel legs visible above water. Riprap
Riprap
Riprap — also known as rip rap, rubble, shot rock or rock armour or "Rip-rap" — is rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour, water or ice erosion.It is made from a variety of rock types, commonly granite or...
covers the river bed around the river pier for scour
Bridge scour
Bridge scour is the removal of sediment such as sand and rocks from around bridge abutments or piers. Scour, caused by swiftly moving water, can scoop out scour holes, compromising the integrity of a structure....
protection against the large flows when the Tees Barrage
Tees Barrage
The Tees Barrage is a barrage across the River Tees just upriver of Blue House Point in the borough of Stockton-on-Tees in North East of England and is used to control the flow of the river, preventing flooding and the effects of tidal change....
downstream discharges. Each of the two concrete riverside piers are supported on four 500 mm hollow steel piles and a pile cap.
The bridge as initially proposed was to have been some 272 m long. It was originally designed with a northern approach 38 m long and a southern approach of 54 m 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. The bridge deck is 5 m wide and 4 m between its handrails. The main arch of the bridge is 120 m long, weighing 300 tonnes, 32 m tall with its top 40 m above the Tees and the short arch is 60 m long and 16 m tall. The hangers (droppers) are spaced 7.5 m apart and are made from 30 mm diameter high strength locked coil steel cable.
Parapet
A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a...
are stainless steel while the balustrade is made from stainless steel wire. To ensure any bridge oscillation is controlled the deck is fitted to the underside with seven tuned mass damper
Tuned mass damper
A tuned mass damper, also known as an active mass damper or harmonic absorber, is a device mounted in structures to reduce the amplitude of mechanical vibrations. Their application can prevent discomfort, damage, or outright structural failure...
s - one on the short arch, and six on the larger weighing 5 tonnes in all. The mass dampers control horizontal as well as vertical oscillations - a feature only required on very slender bridges. There is provision for the addition of further dampers when the issue of maintenance arises. The clearance (heading) below the decking on the navigable part of the river is 8 m.
Illumination
A special feature is made of the way the bridge is lit at night. This lighting scheme was designed by Speirs and Major AssociatesSpeirs and Major Associates
Speirs and Major Associates is a UK lighting design practice founded by Jonathan Speirs and Mark Major in 1992. The practice is particularly noted for its illumination of prominent buildings, including Barajas International Airport, 30 St Mary Axe , the Millennium Dome and the interior of St. Pauls...
who also designed the lighting for the Burj Al-Arab
Burj al-Arab
Burj Al Arab is a 5-star luxury hotel located in Dubai, United Arab Emirates. At , it is the fourth tallest hotel in the world. Burj Al Arab stands on an artificial island out from Jumeirah beach, and is connected to the mainland by a private curving bridge...
. At night the bridge handrail and footway are lit with designer blue and white LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
lighting built into the handrail that changes colour as users cross. 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. 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
Infinity
Infinity is a concept in many fields, most predominantly mathematics and physics, that refers to a quantity without bound or end. People have developed various ideas throughout history about the nature of infinity...
symbol ∞, and it is this effect that inspired its name.
Construction
The bridge was constructed in 18 months between June 2007 and December 2008 by site constructor Balfour Beatty Regional Civil EngineeringBalfour Beatty
Balfour Beatty plc is a British construction, engineering, military housing, rail and investment services company. It is one of the largest construction companies in the UK, and the 15th largest in the world...
and steel fabricator Cleveland Bridge & Engineering Company
Cleveland Bridge & Engineering Company
The Cleveland Bridge & Engineering Company is a renowned bridge building and structural engineering company based in Darlington, England. It has been involved in many major projects including the Victoria Falls Bridge and the Humber Bridge.-History:...
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
Cofferdam
A cofferdam is a temporary enclosure built within, or in pairs across, a body of water and constructed to allow the enclosed area to be pumped out, creating a dry work environment for the major work to proceed...
for the safe construction of the central pier. In April 2008 the supporting legs were added to the central pier. Steel falsework was constructed in the cofferdam by Dorman Long to support the ends of both incomplete arches as they cantilevered over the river during construction. The first steel arch made from four pieces of fabricated steel welded together, was put in place in June 2008 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 its progressive construction of the large arch.
The final section of the main arch came in four pieces which were welded together on site and on 5 September 2008 all 170 tonnes of it was lifted into place by a 1,500 tonne mobile crane, the largest in the country. The crane, a Gottwald AK680 owned by Sarens UK is based in nearby Middlesbrough. The crane is 80 metres (262 ft) high with a maximum of 1200 tonnes of superlift, requires 45 transport wagons to move it, 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. Using a short temporary jetty on the north bank the deck panels were floated out on a small barge and jacked into position working progressively away from the river pier. The concrete deck sections are held together by steel welds and adhesive.
The footbridge was completed on time and to budget in December 2008 with 530 workers and uses in total some 450 tonnes of Corus steel, 1.5 km of locked coil steel cable, 780 lights, 5,472 bolts and weighs 1040 tons. Almost all labour, materials and components were sourced locally.
Operation
The bridge was officially opened on 14 May 2009 with celebrations including a sound, light and animation show, parkourParkour
Parkour is a method of movement focused on moving around obstacles with speed and efficiency. Originally developed in France, the main purpose of the discipline is to teach participants how to move through their environment by vaulting, rolling, running, climbing and jumping...
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. The bridge was opened to the public two days later. Foot traffic is anticipated to rise to some four thousand people a day as the North Shore site develops.
Awards
The bridge won the Institution of Structural EngineersInstitution of Structural Engineers
The Institution of Structural Engineers is a professional body for structural engineering based in the United Kingdom. It has 27,000 members in 105 countries. The Institution provides professional accreditation for structural engineers...
' Supreme Award
Structural Awards
The Institution of Structural Engineers' Structural Awards have been awarded for the structural design of buildings and infrastructure since 1968...
for Structural Excellence 2009, 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 Structural Steel Design Award 2010, the Concrete Society Civil Engineering Award 2009, the ICE Robert Stephenson Award 2009, the North East Constructing Excellence Awards 'Project of the Year', and the Green Apple Award for the environment.
See also
Nearby- River TeesRiver TeesThe River Tees is in Northern England. It rises on the eastern slope of Cross Fell in the North Pennines, and flows eastwards for 85 miles to reach the North Sea between Hartlepool and Redcar.-Geography:...
- Teesdale WayTeesdale WayThe Teesdale Way is a long distance walk between the North Sea coast of North Yorkshire and the Cumbrian Pennines in England. The walk is 100 miles / 161 km in length, it links in with other long distance walks such as the Pennine Way and the E2 European Walk between Harwich and Stranraer.The...
- Teesdale Business ParkTeesdale Business ParkTeesdale Business Park is a major business park on the former site of Head Wrightsons' Teesdale works in Thornaby-on-Tees in the borough of Stockton-on-Tees, England. The park was redeveloped by the Teesside Development Corporation. The area is immediately north of Thornaby railway station,...
- PortrackPortrackPortrack is a housing estate in Stockton-on-Tees. It is situated close to Billingham opposite Thornaby and just West of Middlesbrough. Portrack was the site of a large municipal incinerator which took in and burned waste from all over Teesside. The incinerator was closed in 1996 and demolished in...
- Stockton-on-TeesStockton-on-TeesStockton-on-Tees is a market town in north east England. It is the major settlement in the unitary authority and borough of Stockton-on-Tees. For ceremonial purposes, the borough is split between County Durham and North Yorkshire as it also incorporates a number of smaller towns including...
- Thornaby on Tees
- Tees ValleyTees ValleyThe Tees Valley is an area in the North East of England. It can be described as "greater Teesside" and consists of the four unitary authorities created by the breakup of the County of Cleveland in 1996: Hartlepool, Middlesbrough, Redcar & Cleveland, and Stockton-On-Tees along with the borough of...
Other regional bridge developments
- New Wear BridgeNew Wear BridgeA New Wear Bridge is planned for Sunderland, North East England. The proposed design stands at 180 metres , which when constructed will make it the tallest bridge in England.. Originally designed by Spence Associates Architects in 2005, the plans were kept confidential for several years due to...
External links
- Infinity Bridge on Bridges on the Tyne website
- Bridge design analysis, review and critique: A Critical Analysis of North Shore Footbridge, The Happy Pontilist Blog
- Construction videos: BBC, Evening Gazette
- Opening celebrations video from TFM RadioTFM RadioTFM Radio is a Thornaby-on-Tees based Independent Local Radio station. Launched in June 1975 as Radio Tees, with the callsign "You've got a friend on 257" it was the first independent local radio station serving the area of the Tees Valley with parts of North Yorkshire and County Durham...
- Construction animation: Oasys
- Images: Dorman Long Technology, Flickr, North Shore Stockton, BBC Tees
- Bridge models: Imperial College, Nature's World.