Competition Entry for Bridge over River Douglas

The competition asked for a design for a pedestrian bridge to replace the railway that was now disused.

The shape of the bridge has evolved from the cast iron rail-track, the bridge is on the site of a former rail bridge, the flat bottom developing into a bottom arch that spans across the river. The upper arch produces a torsionally stiff form to resist the wind loads that in off the Irish Sea.

The main structural form of the bridge is a pair of shallow arches spanning approx. 65m across both the river and the two pedestrian zones to either size. Each arch comprises tow curved ribs, connected together with a diaphragm structure to a load generated pattern that replicates the organic form of the superstructure.

The filigree superstructure, currently conceived as a seemingly irregular arrangement of ribs and a tracery of ductile iron or steel castings, will form a rigid continuum and stablise the upper members of the compound arches.