Vattenfall has conducted the a large-scale seabed survey with uncrewed surface vessels. As a part of operating an offshore wind farm it is necessary to periodically survey the seabed around turbine foundations and substation jacket legs to monitor changes in cable burial depth and scour development.This knowledge is also important for repair and maintenance activities involving jack-up vessels, where legs require a stable seabed to ensure safe elevation out of the water.
In the summer and autumn of 2022, uncrewed vessels were used for seabed surveys across Vattenfall’s Horns Rev 1, Horns Rev 3 and Krieger’s Flak in Denmark as well as Lillgrund in Sweden and Thanet in the UK. The uncrewed vessel is significantly smaller (4.5m total length) than crewed vessels. Uncrewed vessels are sailing drones controlled by an operator onshore. The service was provided by ocean data acquisition company Xocean, who has used uncrewed survey services since 2019.
