Artificial seabed; a mooring concept for crossing long and deep waterways

Based on the incentive from the Ministry of Transport and Communications in Norway of replacing ferry crossings with permanent fixed crossings, there is a need for new crossing technology for the deepest and widest fjords. The present paper presents a concept consisting of a floating pontoon bridge with a submerged floating tunnel at mid-span, the latter to facilitate ship traffic. These elements are further side moored down into a submerged anchoring system. The benefits with the presented concept are that there is no need for a tall bridge for the fairway, and the fairway is flexibly placed where it is needed for the specific crossing. The concept is independent of water depth and sea bottom conditions. The concept makes use of technology and element sizes known from both offshore oil- and gas and civil construction. The paper presents the overall concept and the global behavior of the structures.