Neuartige Sanierung der Tragkabel einer Hängebrücke in Norwegen

Innovative rehabilitation of the main cables of a suspension bridge in Norway

As alternative to the traditional painting of locked coil bridge cables, during the last years the automatic wrapping with butyl rubber tapes has been developed. This procedure has the main advantage, that the preparation of the rope surface needs not to be as accurate as for painting and that the traffic on the bridge remains widely undisturbed. So far it has been applied for the individual cables of three cable stayed bridges in Germany.
Recently, the procedure has been applied for the rehabilitation of the main cables of a suspension bridge in Norway. For this, solutions had to be developed for the specific conditions of a suspension bridge like small distance between the ropes of the main cables and the connection of the hangers and cable saddles. The main advantage of the procedure was its speed: in only 25 days 70 % of the total works were finished - in spite of losing six days by adverse climatic conditions. Under these circumstances, a painting of the cables would have been impossible or would have required expensive, water and air tight protective devices.