REHAB WIDENS, STRENGTHENS SUSPENSION SPAN

The rehabilitation of the Tamar suspension bridge between Cornwall and Devon, UK, is described. Since toll revenue was essential to fund the work, it was decided to install two cantilevered traffic lanes, one each side of the bridge, so that it would not have to be closed during repairs. By making these structures permanent, an extra traffic lane enabled the elimination of a dangerous interchange, and additional space for pedestrians and a cycle lane could be included by using the other cantilevered lane. 18 new cables were added to take the extra weight, but the weight of the bridge was only 25 t greater at the end of the project, as the original overstressed concrete deck was replaced by a lightweight orthotropic steel deck.