Severn crossing
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The Severn crossing is generally used to refer to two river crossings over the River Severn between England and Wales. The two crossings are:
- The Severn Bridge (Welsh: Pont Hafren) which is actually one link in the old severn crossing; and
- The Second Severn crossing (Welsh: Ail Groesfan Hafren)
Though strictly speaking, there are a number of other crossings over the River Severn.
The original suspension bridge was inaugurated on September 8, 1966, and the newer cable-stayed bridge, a few miles to the south, was inaugurated on June 5, 1996.
The two Severn crossings are nowadays generally regarded (at least by people in the south of England and South Wales) as the main crossing points from England into Wales, despite the fact that the two share a substantial land border. Prior to 1966 road traffic between the southern counties of Wales and the southern counties of England — including London — either had to travel via Gloucester or take the Aust Ferry, which ran, roughly along the line of the Severn Bridge, from Old Passage near Aust to Beachley. The ferry ramps at Old Passage and Beachley are still visible.
The Anglo-Welsh poet, Harri Webb, wrote these lines:
- Two lands at last connected
- Across the waters wide,
- And all the tolls collected
- On the English side.
The toll is indeed collected on the English side for the original crossing, and only on vehicles travelling from England to Wales. This arrangement eliminates the need for a set of toll booths for each direction of travel and the potential for traffic waiting to pay the toll to back up onto the bridge itself (although this was originally the case). The second Severn crossing has tolls on the Welsh side for travel into Wales.
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First Severn crossing
The original Severn crossing crosses the estuary of the River Severn from South Gloucestershire, just north of Bristol, to Beachley, a peninsula of Gloucestershire between the Severn and Wye estuaries, and crosses the army camp on the peninsula. This crossing consists of several structures which listed in order from England to Wales are: Aust Viaduct, Severn Bridge, Beachley Viaduct and Wye Bridge.
Offa's Dyke placed the Beachley peninsula in Wales, and the Severn Bridge is intuitively thought of as an English-Welsh crossing - which as a section of road it certainly is, there being no access to the roadway from Beachley. So intuitive sense is at odds with the county boundaries which place the Severn Bridge itself wholly in England and the Welsh border at the Wye bridge, the Beachley peninsula being wholly in Gloucestershire.
The crossing starts with Aust Viaduct a twin box girder structure with a concrete deck, which carries the roadway to the first gravity anchorage of the old Severn Bridge. The roadway is then carried over the top of the concrete anchorage to the Severn Bridge.
Beachley Viaduct is also of similar box girder construction as the Severn Bridge but is supported on steel trestles as it crosses the Beachley peninsula.
Wye Bridge, is a 1340 ft (408 m) long cable-stayed bridge, which crosses the border of the River Wye into Wales, 3 km south of Chepstow. The deck is an orthotropic box girder similar to the Severn Bridge but has a different appearance as it has two sets of cable stays on each of two towers (originally there was only one set of cable stays but these were replaced during the strengthening works in the late 1980s).
The Severn 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 existing 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 or towers and so is not visible. The surfacing is a thin layer (about 35 mm) of mastic asphalt over an acrylic waterproofing membrane.
The road is only two carriageways of two lanes in each direction, and as traffic volumes grew it became a major bottleneck. The burden of maintenance also became unmanageable, so that by the 1990s a second crossing was necessary.
Second Severn crossing
Image:SecondSevernCrossing Jan2006.jpg The Second Severn crossing was built by a business consortium, and this time the tolls were collected on the Welsh side near Rogiet (but in the same direction). 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 crossing one has to leave the M4 and join the M48 motorway either at Aust or near Magor. The new crossing carries more traffic than the first bridge which continues in use. Its Welsh end is in Monmouthshire; its English end at Severn Beach in South Gloucestershire.
The second crossing is 3.186 miles (5128 m) long, consisting of a single central navigation span over the 'Shoots' channel and approach viaducts on either side. The central span is of cable-stayed construction. It is wider and more resistant to high winds than the original crossing, having three lanes and hard shoulder each way, compared to the 2 lanes and cyclepath/footpath of the original crossing. The crossing forms a gentle S shape and near the English side crosses over the top of the Severn railway tunnel.
Prior to construction, there was controversy over the environmental impact to the surrounding area. The approach viaducts on the east side are built on the English Stones, a rocky outcrop which is uncovered at low tide. The crossing bridge is built near extensive mudflats in the Severn Estuary, which are used by migrating birds. The main concerns were the immediate damage that could arise from construction work and the longer term problems of traffic pollution.
The Future
The proposed Severn Barrage would constitute a third crossing if it is ever built. It is generally thought that it would carry a road crossing, and until recently a rail link over it has been ruled out because the barrage will contain a huge set of shipping locks that the rails would need to traverse. However, recently it has been suggested that smaller modern trains would be able to handle a rail bridge over the locks, and so a rail link is possible.
See also
External links
- http://www.severnbridge.co.uk - The bridges' operating company. Facts and figures, history etc. about the crossings.