Having adapted its survey technology to various ship structures, DNV GL conducted its first offshore drone survey, in July 2017, on ProSafe's semisubmersible vessel Safe Scandinavia, off Norway. Galinski’s team fitted the Custom drone with a zoom camera. This means that instead of having to fly within distances as short as one metre from the structure, the drone can take high-definition images from further away.
“It was a great opportunity for us to demonstrate our drone’s ability to check the condition of remote external components in challenging offshore conditions. The inspection only required the semisubmersible to deballast. We flew the drone approxi-mately 25 metres below the main deck to check the condition of the fairleads and their connections to the columns that hold up the TSV. With wind speeds of about 15 knots, this went very well and the survey showed that the fairleads and their connections were in a good condition,” says Galinski.
Looking ahead, Mr. Galinski suggests that drones would enable inspections without requirement of lengthy preparations, while ensuring safety. For example, drones could be dropped into inerted compartments where humans cannot enter and the surveyor could stay outside while the drone would follow a predefined flight path to check the condition of the compartment.
In future, it might even be possible for an autonomous drone equipped with artificial intelligence to carry out a survey independently, monitored by the surveyor from the shore office using a virtual-reality headset. For the time being, the autonomous functionality still requires further development, DNV GL noted.
“Outside drones can follow a predefined flight path using a GPS signal. But for confined steel compartments, we need to find an alternative approach,” says Galinski.
In a joint research project DNV GL and the University of Trondheim, Norway, are developing an autonomous drone. With several options under consideration, Galinski expects to see the first autonomous surveys of inerted compartments in the near future.
“Two of our drone pilots have completed the BVLOS (Beyond Visual Line of Sight) certification, allowing them to operate drones beyond the line of sight. So while drone inspections remain a niche for now, more advanced models with AI capabilities could soon transform ship surveys. We want to be ready for this.”