Technicians rappelling down vast blades on the open seas, checking the parts bit by bit; engineers crawling through cramped spaces where air is poor; ships losing time in dock while cranes are used to get engineers to the top of masts: these have been the traditional ways of checking for wear and tear on wind turbines and in ships. But drones provide a new way of approaching the problem. 

The technology used in inspections carried out by autonomous devices, or robots, is getting ever more sophisticated.