Северн және Уай өзендеріндегі көпір

Bridge over the rivers Severn and Wye in England and Wales

the 1966 road bridge across the Rivers Severn and Wye between Wales and England

The Severn Bridge (Pont Hafren) is a motorway suspension bridge that spans the River Severn between South Gloucestershire in England and Monmouthshire in South East Wales. It is the original Severn road crossing between England and Wales, and took three and a half years to build, at a cost of £8 million. It replaced the 137 year old Aust Ferry. The bridge was opened in 1966 by Queen Elizabeth II. For thirty years, the bridge carried the M4 motorway. It was granted Grade I listed status in 1999. The growth of road traffic in the early 20th century led to further calls for improvements, and in the early 1920s Chepstow Urban District Council convened a meeting of neighbouring local authorities to consider a Severn crossing to ease congestion and delays on the A48 passing through the town. In 1935 Gloucestershire and Monmouthshire County Councils jointly promoted a Parliamentary Bill to obtain powers to build the bridge over the estuary, with 75% of costs to be met by the Ministry of Transport from the Road Fund. The bill was rejected by Parliament after opposition from the Great Western Railway Company. After the Second World War, plans began to be made for a nationally funded network of trunk roads, including a Severn Bridge, for which the contract was awarded to Mott, Hay and Anderson, with Freeman Fox and Partners. The public inquiry into the scheme was held on 24 September 1946 at Bristol University. Because Government funding was prioritised for the similar Forth Road Bridge (opened in 1964), construction of the Severn Bridge was not started until 1961: the UK government announced in 1962 that construction costs would be recovered by a toll of 2s 6d (£0.125) on all vehicle crossings, though walking or cycling across the bridge would be charge free. The bridge has been featured in several promotions. In January 1977, it was announced that bridge traffic would be restricted to a single lane in each direction following the discovery of several weaknesses in the ten year old structure. The lane closures would last for several months. The Severn Bridge crossing was strengthened and resurfaced in the late 1980s as the weight of traffic grew. The work included the strengthening of the Severn Bridge towers and deck, an extension to the Wye Bridge towers and the replacement of the original single stays with two stays. The open structure of the new stays is designed to facilitate maintenance. Most of the strengthening work was inside the deck box and towers and so is not visible. Design of the strengthening was by Flint & Neill. The surfacing is a thick layer of mastic asphalt over an acrylic waterproofing membrane. During its 40th year of operation in 2006, the bridge was inspected to check for corrosion of the suspension cables. According to the Highways Agency, the inspection concluded that the bridge needed restrictions on heavy goods vehicles. Such vehicles are now restricted to one lane on the bridge, with weight restriction signs in place. A system of rubber casing on the cables with dry air circulation, as used on the Forth Road Bridge, was installed in 2007–2009 in a move to halt the progress of the corrosion. The bridge is also home to Severn Bridge parkrun, one of the many free, weekly 5k runs held in both the UK and internationally. In October 2021, the Welsh Government announced it is considering reclassifying the M48 into an A road. This is due to lower amounts of traffic on the bridge and M48, following the opening of the Prince of Wales bridge, and the high costs to improve the M48 to motorway standards for the decreased amounts of traffic it handles. Reclassification requires approval from both the Welsh Government and Secretary of State for Wales, with the Department for Transport stating they have no plans to reclassify the M48 in England.

The Severn Bridge crossing consists of four structures, which, in order from England to Wales, are: the Aust Viaduct, Severn Bridge, Beachley Viaduct and Wye Bridge. In 1998 the Severn Bridge and Aust Viaduct were given Grade I listed status, and the Beachley Viaduct (eastern/English end) of the Wye Bridge and the western/Welsh end of the Wye Bridge received Grade II listed status.

The 514 feet (157 m) Aust Viaduct is a twin box girder structure with a concrete deck, An unusual feature of the suspension cables carrying the deck is that they are not vertical, as for most suspension bridges, but rather arranged in a zig zag fashion, with adjacent mounts closely spaced. The triangulation this offers is an attempt to reduce vibration, as is the use of Stockbridge dampers on the cables. The bridge is 5240 feet (1597 m) long, consisting of a 3240 feet (988 m) central span between the towers and the two 1000 feet (305 m) side spans. The towers rise to 445 feet (136 m) above mean high water and are of hollow box construction. The deck is an orthotropic steel box girder of aerofoil shape with cantilevered cycle tracks and footway supported from the box. The shape of the bridge was determined by the designers Freeman, Fox and Partners following wind tunnel tests for the Forth Road Bridge, after the original wind tunnel model was accidentally destroyed. The sections of the deck were built at Fairfield Mabey in Chepstow, and each 132 tonne section was then floated down the river before being hoisted into position.

The 2444 feet (745 m) Beachley Viaduct is of a box girder construction similar to that of the Severn Bridge but is supported on steel trestles as it crosses the Beachley peninsula over the British Army camp, Beachley Barracks, that is home to 1st Battalion, The Rifles. In November 2016 the Ministry of Defence announced that the site would close in 2027.

On 6 February 2009, during a week of snowfall throughout Britain, both Severn bridges were closed simultaneously due to ice falling from the bridge structure and damaging vehicles. On 22 December 2009, both bridges were closed again for the same reason. A privately developed app called Enviroute provides the status of both bridges. The original Severn Bridge status website, www. severnbridge. co. uk, was decommissioned in December 2018 following the removal of the tolls and the handing back of the first bridge to the UK government.