Magnetic Robot Cleans Ship Hulls on the High Seas

One meter long and sixty centimeters wide: that is how small the robot is that works on a container ship. It is placed on the hull surface and then moves along route after route while currents and waves pull at it. It was developed by a student of marine science and mechanical engineering at Northeastern University, while interning at the robotics company Fleet Robotics.

The problem is biofouling, a growth of microorganisms and deposits that attaches itself to ship hulls. The layer increases drag, so ships burn more fuel. It can also harbor invasive species that spread into foreign ecosystems and displace native plants and marine animals. According to heise, the US shipping industry alone faces $36 billion in extra costs, from fuel and from the repeated need to renew antifouling coatings. The situation in the Strait of Hormuz is especially worrying: because of transit restrictions amid the conflict between Iran and the US/Israel, ships are stuck in place for longer, microorganisms settle on their hulls, and scientists see a massive threat to ecosystems worldwide once the ships resume sailing.

The growth cannot simply be removed. It is sticky, and depending on the size of the ship, several tons can accumulate. It has to be removed where it formed, in moving water, where detached material is more easily dispersed into the sea. The robot's brushes are designed so the surface is not damaged, because otherwise corrosion and the release of toxic chemicals become risks. The robot works below the waterline, is built to be waterproof, and withstands high water pressure. Cleaning takes place exclusively on the high seas, not in ports. Several robots coordinate with each other and recharge their batteries on their own at docking stations once power runs low. Navigation runs entirely on the robot itself, via Wi-Fi or cable, since there is no central control.

Who stands to benefit? First and foremost, ship operators whose hulls constantly collect growth, and indirectly the coastlines where species would otherwise be introduced. How much fuel the robot actually saves has not been quantified. When it will move into routine fleet operations remains open: the report gives neither a date nor a price, and so far only one ship has been used for testing.