Bridges presentation
application of iron and steel to bridge construction.
Cantilevers were one of the first bridge types, many being built by the ancient cultures of China and
India. The first modern cantilever was Heinrich Gerber's Hassfurt Bridge over the Main in Germany
(1867), with a central span of 124ft (38m). It was a continuous girder hinged at the points of equal
resistance where the moments of the uniform load were zero. According to W Westhofen, who wrote
the classic account of the Forth Bridge, the idea first was suggested by John Fowler, co-designer of
the Forth Bridge, around 1846-50. In Britain and the USA the form was known as cantilevers, in
France as portes-à-faux, and in Germany as the Gerber Bridge, named after the builder. By inserting
hinges, the continuous girder can be made statically determinant. This was their first attribute, but
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