- Second Severn Crossing
bridge_name=Second Severn Crossing
caption=Second Severn crossing seen from the English side looking West, January 2006
South West England/South East Wales
5 June 1996
long=The Second Severn Crossing (Welsh: "Ail Groesfan Hafren") is a
motorwaycrossing over the River Severnbetween Englandand Wales, inaugurated on 5 June 1996by Charles, Prince of Walesto augment the traffic capacity of the original Severn Bridgecrossing built in 1966. The bridgemarks the lower limit of the River Severn and the start of the Severn Estuary.
Its location is further to the south than the old bridge and being more in line with the landward sides of the
M4 motorway, is a shorter journey when travelling from England to South Wales. The junctions at each end are designed for most traffic to use this crossing – to use the old Severn Bridge crossing one has to leave the M4 and join the M48 motorwayeither at Austor near Magor. The new crossing carries more traffic than the Severn Bridge, which is still in use. It is wider than the Severn Bridge, having three lanes and hard shoulder each way, compared to the two lanes, cycle path and footpath of the original crossing.
In contrast to the original Severn Bridge crossing, the tolls are collected on the Welsh side near
Rogiet(but in the same westbound direction as on the first crossing). Tolls can be only be paid for by cash or cheque, or by use of the Severn TAGsystem, which is a wireless system by which payments are paid electronically as vehicles drive through the toll lane. Cash can be paid at the manned booths or coins can be used at the automated coin gates.
Motorcycles and other vehicles driven by a UK disabled badge holder are exempted from paying a toll, although these vehicles must stop at the toll booth to confirm their eligibility.
The toll prices are updated every year on 1 January in accordance with the Severn Bridges Act of 1992.cite web | url= http://www.severnbridge.co.uk/Tolls2008.pdf | format= PDF | work= Severn River Crossing Plc | title= Severn Bridge Tolls | accessdate= 2007-12-26]
The crossing is convert|3.186|mi|km miles long, consisting of a single central navigation span over the "Shoots" channel and approach
viaducts on either side. The Shoots channel is the deepest section along the width of the Severn estuary, and a longer span was required to ease the passage of shipping under this section. The central bridge section, called the Shoots Bridge, is of cable-stayed design and the central span (between the bridge pylons) is convert|456|m|ft|abbr=on in length. The approach viaducts are of a segmental bridgedesign. Its Welsh end is in Monmouthshire; its English end at Severn Beachin South Gloucestershire. The crossing forms a gentle S shape and near the English side crosses over the top of the Severn railway tunnel.
The sides of the bridge are fitted with special railings to reduce lateral wind loads coming from the Severn estuary onto the traffic and this has reduced the number of times that speed restrictions have been needed. The overall design of the new crossing makes it more resistant to high winds than the old Severn Bridge.
The crossing was built by a business consortium under a
Public-private partnership. A company called Severn River Crossing Plc, led by John Laing plcand GTM-Entrepose, was formed to build the new crossing. [cite web | url= http://www.severnbridge.co.uk/legislation.shtml | title= Bridge legislation | work= Severn River Crossing Plc | accessdate= 2007-12-26] The company also took over the responsibility of managing and maintaining the old Severn Bridge crossing, as well as managing and maintaining the new crossing. The cost of constructing the new crossing was expected to be paid for by tolls collected from motorists using the two crossings. Work on the new crossing began in 1992 with completion in 1996.
Sub-assemblies for the bridge were constructed onshore and then shifted by a large tracked vehicle (similar to that used to move the Apollo and
Space Shuttleat Cape Kennedy) onto a barge, prior to being floated out on the high tide to the appropriate site. The 37 bridge pier foundations on the approach viaducts are convert|98.11|m|ft|1 apart, and consist of concrete pneumatic caissons weighing 37 tonnes, which were sunk into the mud of the estuary. The decking consists of convert|3.5|m|ft|1 post stressed match cast sections, weighing 200 tonnes each.
The cable stayed section of the crossing is over convert|900|m|ft|0 long, consisting of a convert|35|m|ft|0 wide deck made from steel plate girders with a composite
reinforced concreteslab. These were prefabricated on shore and put in place using balanced cantilever methods. There are two convert|149|m|ft|0 high twin leg, reinforced and pre-stressed concretepylons carrying 240 cables which support the bridge deck. Cable vibrations were experienced during construction and secondary cables were added to eliminate this. To avoid detracting from the aesthetics of the primary cables, the secondary cables are very slender and are not very noticeable.
Prior to the bridge's construction environmentalists raised numerous concerns and criticisms, chiefly about the immediate damage from construction work and the effects of long-term pollution from a projected increase in car traffic. The approach viaducts from the east sit on
English Stones, a rocky outcrop uncovered at low tide. And the crossing is built near extensive mudflats in the Severn Estuary used by various migrating birds.Fact|date=September 2007
fullwidth = 9800
fullheight = 1175
caption = View of the Second Severn Crossing from Severn Beach on the English side.
height = 200
* [http://www.severnbridge.co.uk Severn River Crossing PLC]
* [http://www.iht.org/motorway/m4sscscheme.htm The Motorway Archive: M4 Second Severn Crossing]
* [http://www.youtube.com/watch?v=99i0-NgHeiU Timelapse video of the crossing] on Youtube
* [http://www.severntales.co.uk/page66.html River Severn Bridges]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Severn crossing — is a term used to refer to the two motorway crossings over the River Severn estuary between England and Wales. The two crossings are: *The Severn Bridge (Welsh: Pont Hafren ) *The Second Severn Crossing (Welsh: Ail Groesfan Hafren ) The first… … Wikipedia
Severn (disambiguation) — Severn may mean:Persons* Claud Severn * Dan Severn * Joseph Severn (English portrait and subject painter) * Severn Cullis Suzuki, environmental activist, speaker, television host and author * Severn Darden * Severn Teackle Wallis * James Windsor … Wikipedia
Severn Beach — is a village on the mouth of the river Severn in South Gloucestershire, England. A riverside footpath leads beneath the Second Severn Crossing bridge which is part of the Severn Way. The eastern portal of the Severn Tunnel lies on the outskirts… … Wikipedia
Severn View services — is a motorway service station on the M48 motorway near the village of Aust, northwest of Bristol. It is owned by Moto. It was formerly called Aust Services.Originally opened for the M4 motorway, when the road was diverted over the Second Severn… … Wikipedia
Severn Bridge — Infobox Bridge bridge name=Severn Bridge caption=The Severn Bridge seen from the English side of the river. From 1966 to 1996, the bridge carried the M4 motorway. On completion of the Second Severn Crossing the motorway from Olveston on the… … Wikipedia
Severn Bridge — 51.609 2.63847Koordinaten: 51° 36′ 32,4″ N, 2° 38′ 18,2″ Wf1 … Deutsch Wikipedia
Severn Barrage — The Severn Barrage is the name of a number of ideas for building a barrage from the English coast to the Welsh coast over the Severn tidal estuary. Ideas for damming or barraging the Severn estuary (and Bristol Channel) have existed since the… … Wikipedia
Severn-Brücke — 51.609 2.6384 Koordinaten: 51° 36′ 32,4″ N, 2° 38′ 18,2″ W f1 … Deutsch Wikipedia
Severn Tunnel — The Severn Tunnel (Welsh: Twnnel Hafren ) is a railway tunnel in the United Kingdom, linking South Gloucestershire in the west of England to Monmouthshire in south Wales under the estuary of the River Severn.Built by the Great Western Railway… … Wikipedia
Severn Tunnel Junction railway station — Coordinates: 51°35′03″N 2°46′38″W / 51.5842°N 2.7771°W / 51.5842; 2.7771 … Wikipedia