The Severn Bridge - WALES скачать в хорошем качестве

The Severn Bridge - WALES

The Severn Bridge - WALES 2011 cost to cross into wales - Its free to leave Category 1 -- passenger vehicles up to 9 seats - £5.70 Category 2 -- commercial vehicles up to 3,500 kg and buses up to 17 seats - £11.50 Category 3 -- commercial vehicles over 3,500 kg - £17.20 The Severn Bridge is located close to the former Aust Ferry. The bridge is a suspension bridge of conventional design, with the deck supported by two main cables slung between two steel towers. In 1966 the cables supporting the bridge deck were spun from 18,000 miles (29,000 km) of wire. 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 prominent use of Stockbridge dampers on the cables. The bridge is 5,240 ft (1,600 m) long, consisting of a 3,240 ft (988 m) central span between the towers and the two 1,000 ft (305 m) side spans. The towers rise to 445 ft (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 construction was undertaken by Sir William Arrol & Co. and completed in 1966.