Cable-Stayed

​The cable stayed bridge was developed after the second World War. It was not an entirely new concept, that is, where the cables from the deck are directly connected to the supporting columns or piers. This idea had been incorporated into some of the earlier suspension bridges, such as the Albert Bridge, London (1873) and the Brooklyn Bridge, New York (1883) to give the deck rigidity. Two German designers, Dischinger and F. Leonhardt, working independently, built the first cable stayed bridges at Stromsund, Sweden (1955) with a 183 metre span and Dusseldorf, Germany (1957) with a 260 metre span. ​This type of bridge is seen as aesthetically attractive, economic and easier to construct. The bridge can take many forms in the cables may be equal or unequal on both sides of the tower. The towers may be many shapes but a H, A or an inverted Y shape are the most popular. There may be one or two lines of cables and there is no need for the large anchorages as required in a suspension bridge. The cables may also radiate from the top of the tower, as a fan, or be arranged in a parallel manner along the vertical face of the tower, similar to a harp.

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Brooklyn Bridge, New York, USA

© By Tiago Fioreze (Own work) [CC-BY-SA-3.0 http://bit.ly/1esJvAQ, via Wikimedia Commons

The introduction of computer aided design, along with the development of new materials, has greatly assisted the design of cable stayed bridges. They now cover a wide range of spans from 100 to 1100 metres. This form of bridge type has proved to be very attractive for light pedestrian bridges with unusual loading configurations and is also suitable for heavily loaded highways. Concrete and steel are used either separately or as composites in the construction and it is possible to have multiple cable stayed bridges joined together e.g. Lake Maracaibo, Venezuela (1961) and Millau, France (2004). ​The length of spans was increasing on a gradual basis so that in 1991 the record was held by the Skarnsundet Bridge in Norway with a span of 530 metres. This was superseded by the Yangpu Bridge in Shanghai, China in 1993 with a span of 602 metres. Then the Pont de Normandie at Le Havre, France was constructed in 1994 with a span of 856 metres, an increase of 42%. ​This phenomenal increase in span for cable stayed bridges brought this type of bridge construction into competition with the large span suspension bridges and generated a whole new market for cable stayed bridges throughout the world, particularly where suspension bridge designs were under consideration. The current longest cable stayed bridge in the world is Russky bridge, Vladivostok, Russia, with a span of 1104 metres and completed in 2012.
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Samuel Beckett Bridge, Dublin

© Peter Dee