In order to maintain a consistent buoyancy as their cargo loads change, ocean-going ships pump seawater in and out of their ballast tanks. Needless to say, that salty water isn't exactly the least-corrosive liquid in the world. That's why crews of inspectors regularly have to go inside those steel tanks, to check for damage. Thanks to the German/Dutch RoboShip project, however, autonomous robots may soon be performing the task.
Traditionally, in order for its ballast tank to be inspected, a ship must first be pulled out of the water and put in dry-dock. Approximately six inspectors then climb inside the tank, where they risk falling on the slick metal or breathing in noxious fumes. According to the Netherlands' University of Twente, which is one of the project partners, such dry-dock inspections can cost up to €700,000 (US$870,840).
In the RoboShip scenario, however, the ship can stay in the water while inspections are performed.
Moving along a roller coaster-like set of rails built into the ballast tank, an autonomous robot uses a camera and multiple other sensors to inspect the steel. It transmits its video and other data to a human crew outside the tank, who assess it on a computer or tablet screen.
Should they see anything that needs attention, they can determine the present location of the robot within the tank by tracking a magnetic field that it emits. They can then schedule repairs for the next time that the ship is put in dry-dock for maintenance. Down the road, though, the RoboShip designers would like to see the robot using a laser to perform some types of repair work on its own, during the inspection.
RoboShip is one aspect of the larger SmartBot program, which involves 24 research partner groups from Germany and the Netherlands. Prototypes of the rail system, robot and its sensing system have already been built over the past few years. The Meyer Werft shipyard in Germany plans on integrating the technology into ships that it's building.