Pedestrian Bridge in Hörn, Kiel
Forming part of a larger rehabilitation scheme, a simple, uncovered pedestrian link was created between two districts on opposite sides of the harbour. The opening section of this pier-like structure consists of a three-bay bascule bridge 5 m wide and spanning a distance of 25.5 m. In a retracted position, the bridge allows a 22-metre-wide passage for shipping. In a lowered position, the structure corresponds to a classical mono-directional cable-stayed bridge with movable portal masts. To avoid uncontrolled increases in the cable loading, geometric inaccuracies had to be reduced to a minimum. The cable suspension is statically determined in every position. The routing of the cables – which function without hydraulic or spring elements – ensures that they are always in a state of tension and are capable of withstanding frontal wind loads when the sections of the bridge are open. The folding process takes two minutes, during which time all the cables are wound round a single winch, and the railings fold and unfold automatically. In view of the innovative nature of the project, the entire structure was manufactured under workshop conditions. The bridge adopts the bold coloration of the harbour cranes and the ships and is thus set off from the grey waters of the sea. During the first year of operation, when it was opened an average of 11.4 times a day in summer and 8.9 times a day in winter, the bridge demonstrated its efficiency even under strong wind conditions.