Collisions of Ships and Offshore Wind Turbines: Calculation and Risk Evaluation

In Germany and other European countries, a large number of offshore wind parks will be installed within the next decade. Even though this development is promoted by governmental agencies in order to achieve positive effects such as installing a sustained energy and resource management, risks such as pollution due to collisions of tanker vessels with offshore wind energy conversion systems may cause the acceptance of wind energy to decrease. After a collision oil or other harmful substances may be spilled into the sea. It might even be possible for a ship to break apart and sink in a worst case scenario that includes failure of the bearing of the installed nacelle and subsequent impact onto the ship. Numerical crash tests were carried out in order to determine worst cases and to give hints to improve different offshore wind turbine support structures. In combination with statistical data and determination of probabilities of the occurrence of different scenarios, safety assessment analysis can be carried out by certification agencies and administrative authorities.