The end of underwater oil leaks
Oil tankers have often been shipwrecked for various reasons, heavily polluting the seas and ecosystems around them. The EU-funded project 'Double inverted funnel for intervention on ship-wrecks' (DIFIS) aimed to recover hydrocarbons from sunken vessels even in very deep seas. The system features a dome made from fabric, as well as a riser tube made of flexible material and strong synthetic wire. It also includes a buffer bell placed 50 metres below water level to keep the riser tube buoyant. This is a passive, hardy and cost-effective system requiring only periodic monitoring and removal of collected oil. Deploying the system requires a site survey to identify shipwrecks, placement of anchor blocks and launching of the dome, followed by the construction and lowering of the riser tube. This is followed by unfolding of the dome and installation of the buffer bell, at which point the system can finally be disconnected from the installation vessel. A series of tests were conducted on motion, loads, tension on mooring lines and offloading hose among other components to ensure the viability of the concept. More strenuous tests were then conducted for survival, operation, offloading and deployment. All the tests were successful, demonstrating that the system has much promise if exploited to its full potential. DIFIS results should have a positive impact on maritime habitats and save many ecosystems from destruction, preserving biodiversity and averting full-scale ecological disasters.