Abstract
The rapid development of offshore wind farms coincides with a growing amount of ship movements. This combination puts pressure on maritime safety, especially in the North Sea where space is limited. This risk was demonstrated at January 31st 2022, when bulk carrier Julietta D got adrift in a wind farm under construction. MARIN estimated that the annual probability of a collision between a ship and a wind turbine will be 1.5–2.5/year in 2030.
There are several mitigations possible to prevent ship-to-turbine collisions. As addition to the existing measures, MARIN investigated another innovative solution, a ‘crash barrier at sea’. A variety of barriers has been conceptualized by a team of industry experts. Out of this variety, three concepts were distilled for further analysis: A) a floating surface line, B) a mid-water buoy line and C) a pile supported net.
To test the three concepts, explorative scale model tests have been performed in MARIN’s Offshore Basin. As a reference case, a free drifting vessel similar to the Julietta D, in scaled storm conditions similar to January 31st 2022, was modelled. In general we can conclude based on these very initial experiments that collisions between drifting ships and offshore windturbines can in principle be prevented with these types of barriers, but also that they need further development, validation and evaluation with all partners involved.
