To utilize the ocean space, i.e., the offshore oil and gas development, the renewable energy, crane lifting operations in the ocean are crucial for constructing offshore structures and installing facilities on the seafloor, and safety and availability of the crane lifting operation must be analyzed when planning construction. Wave-induced coupled dynamics between a vessel and a suspended load need to be predicted for these analyses as the coupled dynamics can result in more complex mechanics. Co-operative multi-crane lifting operation with two vessels is often selected in order to lift the heavy susp. load. The mechanics in the cooperative multi-crane lifting with two vessels is more complex than single crane operation with a vessel. A thorough understanding of the coupled dynamical mechanics is required when using a multi-crane lifting with two vessels. Unfortunately, there’re few research activities regarding to the fundamental mechanics and the motion analysis in the multi-crane lifting operation with two vessels. Given these motivations, we conducted both model experiment and numerical calculation to investigate the wave-induced coupled dynamics during the multi-carne lifting operation with two different displacement vessels. We investigated the impact of the susp. load and the distance between two vessels on the coupled dynamics.
Crane lifting operations in the ocean are crucial for constructing offshore structures and installing subsea facilities on the seafloor. Safety and availability of the lifting operation must be analyzed when planning the construction. Wave-induced coupled dynamics between a vessel and a susp. load need to be predicted for these analyses as the coupled dynamics can result in more complex mechanics than just dynamics of a floating structures. Cooperative multi-crane lifting operation with two vessels is often selected in order to lift the heavy susp. load (Winsen, 2019). The mechanics in the cooperative multi-crane lifting with two vessels is more complex than single crane operation with a vessel. In such situation, the connection of the two vessels to the susp. load means that all actions taken on one vessel influence not only motions of the susp. load but also the another vessel. Therefore, as DP system in these working vessels needs to be designed optimally considering the such characteristic mechanics for safety position keeping, a thorough understanding of the coupled dynamical mechanics is required when using the cooperative multi-crane lifting with two vessels.
