Preliminary Design and Hydrodynamic Analysis on the Offshore Integrated Anemometer Mast During Wet-Towing

An offshore integrated anemometer mast (OIAM) is proposed to integrate the offshore installation of the foundation and steel mast into one operation. It can be prefabricated onshore and transported to the installation site which is simple in construction, rapid in speed and saving in cost. The most critical technique of the OIAM is the self-floating towing technique with a reasonable subdivision inside the floating tank. These subdivisions of OIAM facilitate the floating stability in case the occurrence of a damaged compartment. The tank will be ballasted to lower OIAM down and to penetrate these shallow skirt plates underneath into the sea bed after a free-floating towing process. To study and predict the dynamic behaviors of the OIAM in different sea conditions considering different towing critical factors, the hydrodynamic software MOSES is used to simulate the three-dimensional motion of the OIAM in the towing operation. Before that the integrated installation technique is introduced in terms of structure design, towing operation, and sinking on-site. The numerical results show that multiple subdivisions guarantee an adequate floating stability, and the hydrodynamic features indicate that a relative small dynamic response in some extreme sea state can be obtained by this OIAM structure. The self-floating technique of OIAM in sea is highly competitive for saving cost by using less expensive equipment in towing transportation.