Both of these were changed in 2010, however, the bearing and shaft were still the original ones from 1957. The bearings were now worn out and had to be replaced. The four shafts were also to be changed. Each shaft weighed 1,6 tons and measures 1,5 meters. The bridge is 224 meters long and each bridge flap 22 meters long.
JHS Engineering was responsible for the bridge repairs. They had planned on using nitrogen to cool down the connection points. However, calculations showed that this would be pretty expensive and the results uncertain.
"We chose to contact EFD Induction to see if heating the connection ring by induction would be a better solution. It proves to be an excellent and perfect choice," says Project Manager in JHS Engineering, Atle Sigurdsen.
JHS Engineering worked closely together with EFD Induction Norway on the bridge and was impressed with what they experienced.
Terje Solgaard, Application Engineer EFD Induction Norway, explains that the holes, which the shafts are fastened to, are a little bit smaller than the diameter of the shaft.
"We had to make sure that the heating was quick, repeatable and accurate. We knew all the time that this task was meant for induction" emphasizes Terje Solgaard and adds that he never doubted that EFD Induction would succeed.
"We held our breath when the first shaft was put in place. The shaft fitted perfectly. If we had failed it would have caused us huge delays in the project and the opening of the bridge" says a happy customer.