Collision Risk Analysis for Offshore Structures and Offshore Wind Farms

For the approval process of offshore platforms and offshore wind farms, risk analyses that consider collisions between ships and stationary offshore structures are helpful and sometimes necessary. Ship traffic, meteorological and hydrological data are important input information for the investigated sea area. Possible collision scenarios with powered ships sailing into the structures and disabled ships drifting into the structures have to be investigated to determine the collision probabilities and the consequences. Furthermore, risk control measures have to be examined and assessed in such risk analyses. In recent years, Germanischer Lloyd has developed and applied suitable methods and procedures to evaluate the collision risk, including the influence of risk control measures. For these analyses, Germanischer Lloyd developed an analysis software that uses Monte Carlo simulations. For the evaluation of different risk control measures, Bayesian nets are used to determine the reduction of the collision probabilities for powered and drifting vessels and the corresponding risk. In this paper, the methods and processes that were developed are presented together with results of a sample collision risk analysis. Moreover, experience in the practical application of collision risk analyses is discussed, as part of the approval process for offshore wind farms.