Dan Cruickshank’s Bridges: Heroic Designs that Changed the World
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Dan Cruickshank’s personal, passionate and learned journey into the very awe-inspiring architectural icons which have transformed culture, society, industry and landscapes throughout the world – bridges.Bridges define places. Imagine San Francisco without the Golden Gate Bridge, Manhattan without the Brooklyn Bridge, or Sydney without Sydney Harbour Bridge.Not only this, but they are spectacles of engineering, and have influenced the development of cultures, economies, environments and lives in more ways than we can count. Now, Dan Cruickshank looks at what bridges mean to us, and draws on some of his personal favourites from all over the world to tell the story of their architectural, cultural and aesthetic influence.Chapters include:EMPIRE – Bridges from the Roman and ancient worldNATURE AGAINST NATURE -Timber bridgesREVOLUTION – Pioneering structural designs from North America and EuropeUNITING PEOPLE – Bringing nations, cities, and communities togetherVISIONS – Contemporary structures
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Heroic Designs that Changed the World
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The permutations of materials and structural principles employed in bridge construction are seemingly many, varied and complex – timber, brick, stone, cast and wrought iron, steel, hydraulic cement, mass concrete and steel-reinforced concrete, arches of diverse form, beams, cantilevers, pylons, cables and masts. But in its aim bridge construction is straightforward and construction simple. The object is to link two points of land as safely and efficiently as possible. If the obstacle being bridged is running water, then the ideal is to achieve wide spans with minimal support rising from the water to make the bridge easier to build and maintain, to avoid disturbing navigation, and to reduce the risk of the bridge being swept away.
In essence bridge construction is of two basic types. The carriageway – be it for vehicles or pedestrians – is either supported from below or suspended from above. If the ‘dead’ load of the carriageway (its weight) and the ‘live’ load of the carriageway (the weight of the use it carries plus the ‘environmental load’ comprising the weight and pressure of rain, snow and wind) are supported from below it must be carried on arches or vaults of varied types; on beams either cantilevered from, or supported by, abutments and piers; or set within a lattice-like engineered truss wrought of timber or metal. There are two models of nature for support from below: rock formations that arch over; and timber logs or beams laid across, chasms or rivers.
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