Orwell Bridge
Encyclopedia
River Orwell
The River Orwell flows through the county of Suffolk in England. Its source river, above the tidal limit at Stoke Bridge, is known as the River Gipping. It broadens into an estuary at Ipswich where the Ipswich dock has operated since the 7th century and then flows into the North Sea at Felixstowe...
just south of Ipswich
Ipswich
Ipswich is a large town and a non-metropolitan district. It is the county town of Suffolk, England. Ipswich is located on the estuary of the River Orwell...
in Suffolk
Suffolk
Suffolk is a non-metropolitan county of historic origin in East Anglia, England. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east...
, 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 main span is 190 metres which, at the time of its construction, was the longest pre-stressed concrete span in use. The total length is 1,287 metres from Wherstead
Wherstead
Wherstead is a village and a civil parish located in county Suffolk, England. Wherstead village lies south of Ipswich. It is an ancient settlement, and from its soil the plough has brought to light many evidences of occupation by Romans and by early Britons. In the Domesday Book the place is...
to the site of the former Ipswich Airport
Ravenswood, Ipswich
Ravenswood is a district within Ipswich, Suffolk, UK. It is sited on the old Ipswich Airport to the south-east of the town.The area is one experiencing rapid growth in housing numbers from private housing developers...
. The width is 24 metres with an air draft of 43 metres. Pilings were sunk 40 metres into the river bottom. The main contractor was Stevin Construction B.V. - a Dutch company.
Construction of the bridge commenced in October 1979 and was completed in December 1982. The main span was constructed by using a balanced cantilever technique, casting sections on alternating sides of the pier in a weekly cycle.
The bridge is constructed of a pair of continuous concrete box girders
Box girder bridge
A box girder bridge is a bridge in which the main beams comprise girders in the shape of a hollow box. The box girder normally comprises either prestressed concrete, structural steel, or a composite of steel and reinforced concrete. The box is typically rectangular or trapezoidal in cross-section...
with expansion joint
Expansion joint
An expansion joint or movement joint is an assembly designed to safely absorb the heat-induced expansion and contraction of various construction materials, to absorb vibration, to hold certain parts together, or to allow movement due to ground settlement or earthquakes...
s that allow for expansion
Thermal expansion
Thermal expansion is the tendency of matter to change in volume in response to a change in temperature.When a substance is heated, its particles begin moving more and thus usually maintain a greater average separation. Materials which contract with increasing temperature are rare; this effect is...
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
Alton Water
Alton Water is a manmade reservoir. It is the largest in Suffolk, with a circumference of over 8 miles .-Construction:...
reservoir. The necessary inspections still cause major disruption to traffic every six years; during the last inspection in the summer of 2005 the delays caused by lane closures and speed restrictions added between 30 to 60 minutes to journey times during the peak commuting periods.
The bridge design took into consideration the impact on the Orwell Estuary
River Orwell
The River Orwell flows through the county of Suffolk in England. Its source river, above the tidal limit at Stoke Bridge, is known as the River Gipping. It broadens into an estuary at Ipswich where the Ipswich dock has operated since the 7th century and then flows into the North Sea at Felixstowe...
, as well as the needs of the Port of Ipswich. The location close to the Southern edge of Ipswich
Ipswich
Ipswich is a large town and a non-metropolitan district. It is the county town of Suffolk, England. Ipswich is located on the estuary of the River Orwell...
was chosen to be convenient for the industrial areas of the West Bank Terminal and Ransomes Industrial Estate
Ransomes Industrial Estate
Ransomes Industrial Estate, also known as Ransomes Europark is combined retail and business park on the South-Eastern edge of Ipswich in Suffolk, UK...
on the eastern end. The bridge was set at an angle to the river to get the best relationship to the surrounding terrain
Terrain
Terrain, or land relief, is the vertical and horizontal dimension of land surface. When relief is described underwater, the term bathymetry is used...
.
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
Road-traffic safety
The term road traffic safety is about the risk of a person being killed or seriously injured while using the road network as a pedestrian, cyclist, motorist or user of on road public transport...
, there have not been enough incidents causing injury for the Highways Agency
Highways Agency
The Highways Agency is an executive agency, part of the Department for Transport in England. It has responsibility for managing the core road network in England...
to identify it for greater detailed investigation and possible amendments. 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
Department for Transport
In the United Kingdom, the Department for Transport is the government department responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland which are not devolved...
funded the project and, partly because of the Bridge, paid for radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
s and cameras to be installed at the Port's Orwell Navigation Service to monitor the river and the bridge.
The bridge has become vital to Ipswich with over 60,000 vehicles using it per day, which is about 83% of its capacity. When the bridge is forced to close, either due to high winds or accidents, there is a significant impact on the urban road network, bringing many of Ipswich's roads to near-standstill. The bridge is expected to be running over capacity by 2015.
The bridge appears in the 1987 Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
drama The Fourth Protocol
The Fourth Protocol (film)
The Fourth Protocol is a 1987 Cold War spy film starring Michael Caine and Pierce Brosnan, based on the novel The Fourth Protocol by Frederick Forsyth.- Plot :The plot centres on a secret 1968 East-West agreement to halt nuclear proliferation...
, in which two RAF helicopters are shown flying under it.
It is rumoured that several construction workers died during the erection of the Orwell Bridge, many of which are still hard.
Bridge bearing replacement works were carried out during a 52hour closure of the North Deck, carrying the Eastbound A14, over the weekend of 11th-14th February 2011. The new bridge bearings were designed and manufactured by Freyssinet Ltd.