Field experiments on wet tows of an integrated transportation and installation vessel with two bucket foundations for offshore wind turbines

Bucket foundation has been used for offshore wind turbine in Qidong city, China. In order to transport and install bucket foundations together with the upper offshore wind turbines, a non-self-propelled integrated transportation and installation vessel is designed. Wet tow of the dedicated vessel with two bucket foundations and the upper offshore wind turbines, one of the key issues of the integrated transportation and installation techniques, has been studied through a series of field experiments with different air pressures inside the bucket foundations and different ballasts in the vessel. The motion behaviors of the dedicated vessel are investigated. The results show that the dedicated vessel is quite stable during wet tows. In addition, with the air pressures inside the bucket foundations increase, the vessel becomes more stable. However, larger draft makes the vessel less stable and the ballast in the vessel may have little effect on the stability.