The new Dee Crossing Bridge, Pont Sir y Fflint, is the key stage in the completion of a new scheme to improve access and relieve congestion on the A548 trunk road between North West England and North Wales. The new route starts on the A548, turns north to cross the main Chester to Holyhead railway on a highly skewed bridge, almost like a tunnel, and leads on to the approach viaduct to the new bridge. This bridge is 950m long and has an almost 200m long asymmetric cable-stayed main span over the river. Beyond the bridge, the new road descends gradually and curves northwards. The bridge's requirement for lighting was not included in its original design, but a subsequent safety review recommended that lighting be provided for the bridge and its associated highways; the lighting design had to be accommodated within the existing bridge design. Some unique technical solutions were devised to meet the lighting requirements, to provide appropriate levels of illumination to a prominent North Wales landmark in a sensitive and practical way. The scheme also provides suitable lifetime, durability, and ease of maintenance. Floodlights projecting powerful narrow beams were placed in the bridge tower to illuminate the bridge roadway. Aircraft navigation lights are provided at the top of the tower and at another position.
Abstract