Orwell Bridge Explained

Bridge Name:Orwell Bridge
Carries:Motor vehicles (A14 and A12)
Crosses:River Orwell (Freston Reach), B1456
Locale:Ipswich (east) and Wherstead (west)
Maint:National Highways
Architect:Frederick Gibberd Partners
Engineering:Sir William Halcrow & Partners[1]
Design:Twin box girder bridge
Material:Pre-stressed reinforced concrete
Length:1287m (4,222feet) [2]
Spans:18
Builder:Stevin Construction B.V.
Fabricator:Høsveis & Bofa
Begin:October 1979
Complete:April 1982
Cost:£23.6m
Inaugurated:17 December 1982
Preceded:Stoke Bridge
Coordinates:52.0269°N 1.1645°W
Os Grid Reference:TM163445

The Orwell Bridge is a concrete box girder bridge just south of Ipswich in Suffolk, England. Opened to road traffic in 1982, the bridge carries the A14 road (formerly the A45) over the River Orwell.

History

Design

The main span is 190 metres which, at the time of its construction, was the longest pre-stressed concrete span in use in the UK. The two spans adjacent to the main span are 106m, known as anchor spans. Most of the other spans are 59m. The total length is 1,287 metres from Wherstead to the site of the former Ipswich Airport. The width is 24 metres with an air draft of 43 metres; the bridge had to be at least 41 metres high. The approach roads were designed by CH Dobbie & Partners of Cardiff,[3] later bought by Babtie, Shaw and Morton then Jacobs in 2004.

The bridge is constructed of a pair of continuous concrete box girders with expansion joints that allow for expansion and contraction. The girders are hollow, allowing for easier inspection, as well as providing access for services, including telecom, power, and a 711mm water main from the nearby Alton Water reservoir. The necessary inspections still cause major disruption to traffic every six years; during the inspection in the summer of 2005, the delays caused by lane closures and speed restrictions added between 30 and 60 minutes to journey times during the peak commuting periods.

The bridge design took into consideration the impact on the Orwell Estuary, as well as the needs of the port of Ipswich. The location close to the southern edge of Ipswich was deemed convenient for the industrial areas of the West Bank Terminal and Ransomes Industrial Estate on the eastern end. The bridge was set at an angle to the river to get the best relationship to the surrounding terrain.

The air draft of the central span was chosen to be as low as possible without adversely affecting port operations. Although some have said that the resulting hump affects visibility and road safety, there have not been enough incidents causing injury for the Highways Agency to identify it for greater detailed investigation and possible amendments.[4] The consulting engineers were Sir William Halcrow and Partners. Frederick Gibberd Partners worked on the project to ensure the bridge was as sympathetic as possible to its surroundings, with the final design winning the approval of the Royal Fine Art Commission.

The Department for Transport funded the project and, partly because of the bridge, paid for radars and cameras to be installed at the port's Orwell Navigation Service to monitor the river and the bridge.

Construction

Pilings were sunk 40 metres into the river bottom; Pigott Foundations of Ormskirk drilled 1142 piles; the main contractor of the substructure was Stevin Construction B.V., a Dutch company. The main span was constructed using a balanced cantilever technique, casting sections on alternating sides of the pier in a weekly cycle. Høsveis & Bofa of Hønefoss in Norway helped form the box girder (steelwork). The roller bearings were from Maurer AG of Germany. Mageba UK (Swiss) of Bicester supplied the bridge bearings and expansion joints. The pre-stressed concrete box girder sections had VSL tendons and GKN super-strand wire rope. The construction gantries were fabricated by Fairfield Mabey.

It was part of the first section of the Ipswich Bypass; the contracts for the approach roads were given to Costain (£10.7m, eastern) and Cementation (£9.3m, western). For this section of the bypass, Robert McGregor & Sons, subcontracting to Cementation laid 6,900m of concrete in 48 days with a slipform paver; Costain laid 10,400m of concrete in 31 days with a concrete train.

Construction of the bridge began in October 1979 and was completed 1 April 1982. It was opened on 17 December 1982 by David Howell, Baron Howell of Guildford, then the Secretary of State for Transport.

Maintenance

Bridge bearing replacement works were carried out by Jackson Civil Engineering Ltd over the weekend of 11–14 February 2011, during a 52-hour closure of the north deck, carrying the eastbound A14. The new bridge bearings were designed and manufactured by the engineering company, Freyssinet Ltd.[5]

In February 2014, a meeting of various agencies was held to review diversions when it is necessary for the A14 and Orwell Bridge to be closed.[6]

Speed limit

A permanent reduced speed limit of 60 mph was introduced in November 2015 for safety reasons.[7]

Due to high side-winds, the bridge is often closed during storms.[8] To reduce closure time and the pressure it imposes on local roads, in 2021 Highways England installed electronic variable speed limits on the bridge and the approaches each side. During certain high winds conditions, rather than closing the bridge, the speed limit can be reduced from 60mph to 40mph.[9] [10]

Structure

The Stour and Orwell Walk passes under the bridge.

Usage

the bridge was used by 60,000 vehicles per day, about 83% of its capacity.[11] In 2006 it was predicted that the bridge is expected to be running over capacity by 2015.[12] By 2023, traffic levels had exceeded 67,500 vehicle per day.[13]

Incidents

Total closures

When the bridge is closed in both directions for more than a short period of time, normally as a safety precaution due to high winds, most of Ipswich's roads are brought to a near-standstill by diverted traffic.

DateDuration (hours)ReasonNote
14 February 20244 hours 45 minsPolice Incident
21-22 January 202418.5 hoursHigh windsStorm Isha
1 December 2023[14] 12 hoursRoadworksA vehicle carrying survey equipment on the Orwell Bridge during road works had a failed hydraulic unit, which had an extending platform, which was stuck under the bridges surface. A maintenance truck had to be called in from Yorkshire, which caused the worst traffic delays to date in Ipswich.
2 November 20231.5 hoursPolice Incident
2 November 202312 hoursHigh windsStorm Ciarán
18 February 2022[15] 12 hoursHigh windsStorm Eunice
30 April 2019[16] 1.5 hoursPolice Incident
16 March 2019[17] 4 hoursHigh winds
13 March 2019[18] 8 hoursHigh windsStorm Gareth
29 November 2018[19] 4 hoursHigh winds
24 January 2018[20] 5+ hoursHigh windsStorm Georgina
18 January 2018[21] 3 hoursHigh windsStorm Fionn
3 January 2018[22] 17 hoursHigh windsStorm Eleanor
20 October 2017[23] 8 hoursTraffic collisionFatal crash (6:45am to 2:50pm)
23 February 2017[24] 5+ hoursHigh windsStorm Doris
22 November 2016[25] [26] 5+ hoursHigh windsStorm Angus
28 March 2016[27] 5+ hoursHigh WindsStorm Katie
1 July 2015[28] 0–1 hoursSuicide / Attempted Suicide
15 April 20151-1.5 hoursRoad Traffic Collision
16 December 20141-1.5 hoursPedestrian
29 October 20140–1 hoursSuicide / Attempted Suicide
21 July 20140–1 hoursSuicide / Attempted Suicide
13 June 20140–1 hoursPedestrian
14 February 2014[29] 5+ hoursHigh winds2013–14 United Kingdom winter floods
28 October 2013[30] 5+ hoursHigh windsSt. Jude storm
4 March 2012[31] 5+ hoursRoad Traffic collisionBridge closed from 8pm on 4th to 3am on 5th.

Popular culture

The bridge appears in the 1987 Cold War drama The Fourth Protocol, in which two RAF helicopters are shown flying under it, and at the end of the 2013 film The Numbers Station.

External links

Notes and References

  1. https://www.e-periodica.ch/cntmng?pid=bse-pe-002:1981:5::25 IABSE
  2. Web site: The Orwell Bridge . National Highways . 20 May 2020 . 23 February 2023.
  3. http://www.ciht.org.uk/download.cfm/docid/005FBD32-D8C2-4500-9BBC4E728F4AE1A3 IHT The Highway Engineer January 1983
  4. News: Roger. Chenery. Road safety on the A14 around Ipswich. 4 February 2005. Highways Agency.
  5. Web site: Freyssinet Bearing Replacement on A14 Orwell Bridge . 5 May 2011 . https://web.archive.org/web/20110816184502/http://freyssinet.co.uk/pdfs/case_studies/repairs/bridges/SR_038%20A14%20Orwell%20Bridge%20Phase%204.pdf . 16 August 2011 . dead .
  6. Web site: Ipswich/Suffolk: Summit to look at diversions when A14 and Orwell Bridge are forced to close. 28 February 2014 .
  7. Web site: Safety improvement work begins on Orwell Bridge. 12 October 2017 .
  8. News: 2020-01-13 . Orwell Bridge in Suffolk closes for 10 hours due to wind . en-GB . BBC News . 2023-08-12.
  9. News: 2021-03-31 . A14 Orwell Bridge: New speed limit signs installed at Ipswich . en-GB . BBC News . 2023-08-12.
  10. Web site: Highways . National . 2021-01-11 . Orwell Bridge new speed limits during high winds - National Highways . 2023-08-12 . nationalhighways.co.uk . en-GB.
  11. Web site: East of England Regional Assembly. Newmarket to Felixstowe Corridor Study (Section 4.16). 19 June 2006. https://web.archive.org/web/20070928103557/http://www.eera.gov.uk/Documents/About%20EERA/Policy/Planning%20and%20Transport/PlanHome/PlanTranStud/TransportStudies/MultiModalStudies/NewFelix/key%20issues.pdf. 28 September 2007. dead.
  12. Web site: Planning Inspectorate. Port of Felixstowe South Reconfiguration Evidence (Section 7.4). 19 June 2006.
  13. Web site: Department for Transport. Manual count points - Site number: 38454. 3 August 2024.
  14. Web site: 2023-12-01 . Recap after the Orwell Bridge was closed . 2023-12-03 . East Anglian Daily Times . en.
  15. Web site: 2022-02-18. Storm Eunice traffic chaos as heavy winds and snow close roads and bridges across UK. 2022-02-18. inews.co.uk. en.
  16. Web site: Highways England on Twitter. Twitter. en. 2019-04-30.
  17. Web site: Highways England on Twitter. Twitter. en. 2019-03-20.
  18. Web site: Highways England on Twitter. Twitter. en. 2019-03-13.
  19. Web site: Highways England on Twitter. Twitter. en. 2018-11-29.
  20. News: Orwell Bridge CLOSED due to high winds. Ipswich Star. 2018-01-24. en.
  21. News: Will the A14, Orwell Bridge, close in Suffolk due to high winds? Suffolk police reopen the bridge. Hirst. Andrew. Ipswich Star. 2018-01-18. en.
  22. News: A14 Orwell Bridge reopens before evening rush hour. Howlett. Adam. Ipswich Star. 2018-01-05. en.
  23. Web site: A14 Orwell Bridge opens after being closed for 8 hours after fatal traffic collision. 20 October 2017 .
  24. Web site: A14 Orwell Bridge to stay open today as region deals with aftermath of Storm Doris. 24 February 2017 .
  25. Web site: Orwell Bridge fully reopens after high winds closed A14 over the river and caused traffic disruption for thousands around Ipswich.
  26. Web site: Orwell Bridge in Suffolk re-opens.
  27. Web site: Storm Katie wreaks havoc across the East.
  28. Web site: Orwell Bridge Closures. 21 December 2016 .
  29. Web site: Suffolk/Essex: Orwell Bridge due to re-open this morning following strong overnight winds.
  30. Web site: Big storm: Orwell Bridge reopened in both directions as St Jude's storm begins to subside.
  31. No further details of this incident available from local news outlets such as East Anglian Daily Times