EU project designs oil recovery vessel
Oil Sea Harvester, an EU funded project, is developing an innovative ship design for tackling oil spills in rough seas. The decision to design such a ship was made in the aftermath of two major European oil tanker disasters. On 12 December 1999 the oil tanker Erika broke in two off the coast of Brittany, France, whilst carrying approximately 30,000 tonnes of heavy diesel oil. Some 13,000 tonnes leaked into the sea. Three years later, the oil tanker Prestige with its cargo of 70,000 tonnes of heavy fuel oil was to meet the same fate off the north-west coast of Spain. Up to 4,000 tonnes leaked from the ship before it went down. Hampered by bad weather, the clean-up operations on both occasions were unable to stop the oil spill reaching the French and Spanish coastlines. 'When I saw the Erika catastrophe, I saw that existing oil recovery vessels were unable to operate in the rough seas, nor recover the highly viscose oil,' Christian Gaudin, naval architect and Oil Sea Harvester coordinator, told CORDIS News. Waiting for a calm sea is not an option in catastrophes like these, says Mr Gaudin, the longer the clean-up operation takes, the more likely it is that the oil will separate and mix with water and debris, making it much more difficult to recover. 'I started to think that a dedicated ship was needed that could respond quickly to such catastrophes and operate immediately in bad weather conditions,' he said. The design that Mr Gaudin and his team came up is a trimaran, 138 metres long and 38 metres wide, which consists of a large central monohull and two side hulls. These side hulls help to stabilise the ship, enabling it to withstand gale force nine winds and seas up to force seven. In addition, the two hulls also create two eight metre channels of calmer water in which to recover the oil. 'This design is unique because some countries may have supply ships equipped with recovery tools, but they don't have the means to work in choppy sea conditions,' claims Mr Gaudin. Placed within these channels are the recovery tools, consisting of a brush conveyor belt system for high viscose oils and a weir type skimmer for light oil. 'While the belt can recover 99% of the totality of the oil spilled, the skimmer is there to finish off the job,' explains Mr Gaudin. The ship design also includes containment booms that can be deployed autonomously to enhance the available skimming area, and two remote-controlled skiffs (small boats) fitted with toxicity and explosives sensors, to determine how volatile the spill might be. The ship could also be equipped with heating coils and other equipment for oil treatment. Feasibility studies suggest that the Oil Sea Harvester could recover up to 250 tonnes of oil per hour, and that it has the capacity to store a maximum of 6,000 tonnes onboard. With a transit speed of 20 knots, the project partners say that the trimaran is capable of arriving rapidly at the site of an oil slick. Once there, the ship's speed could go down to as low as one knot for the oil recovery. With the project coming to an end in December, the project consortium will be looking out for potential partners interested in financing the construction of a prototype. But the advantages to be had from Oil Sea Harvester do not come cheap. Mr Gaudin estimates that it could cost between €50 and €100 million to build the vessel. A selling point though, according to the project consortium, is that the ship could also be used for such tasks as coastguard patrol and customs, towing, scientific work or container recovery.