Ocean-Cleaning Ship

Following a number of oil spill incidents the ALSTOM's Marine Sector construction yard at Saint Nazaire, which usually builds cruise liners and other specialist vessels, is now turning its attention to the problem of oil spills. The company is developing a new vessel concept – trimaran called Oil Sea Harvester (OSH). In the event of an oil spill, this 120m trimaran would be capable of arriving very quickly on the scene. It could operate in gale force 7 winds and 8m waves, to collect, store and treat a slick before it hits a beach.

The Harvester has a large slender central hull, plus two lateral stabilising hulls. The principle is simple - when water lies in the protected area between the hulls, its surface stablises.

Various methods can be then used to collect the surface oil including the use of modular cyclones, pumps, water wheels or scoops. Water can be removed by heating or chemical treatment, enabling the ship to collect up to 6,000 tonnes of oil before needing to return to land. At the same time, a dispersing product could be spread on the surface of the sea to break down remaining hydrocarbons into harmless tiny droplets. A model of the OSH has already been built and tested.