Norshordland bridge

Crossing Norway's Salhus Fjord required access roads, a high level cable-stayed bridge, and a floating bridge constructed as a steel box on ten separate, lightweight pontoons. The floating bridge plan is an arc with a 1700 meter radius between abutments. A tidal variation in the fjord of up to 1.8 meters leads to very high stresses in the structure because it is anchored only at each end. In areas with the highest stresses (from the abutment past the first pontoon), steel with a yield strength of 460 N/mm² was used.

The steel box girder was fixed to the abutments by means of special "flexible" plate connections of HSS. The elements were designed as two sets of four 3.5 meter long plates. This hinge design simplified installation, reduced costs and is expected to require less maintenance compared to traditional anchorages. High strength steel also helped to solve cross section design problems of the segments without altering the dynamic characteristics of the bridge.

In general, higher material costs for HSS were offset by savings from using less material. In addition, the thinner plates made possible less welding, easier handling and fabrication, and lower transportation and erection costs. The actual saving was estimated at 10 to 15% of the total project costs.