A diving contractor’s removal of oil from the wrecked research vessel Thetis has confirmed the Swedish Sea and Water Authority’s (Hav och Vattenmyndigheterna) expectation that the Miko Moskito offers the best technical and economic option for such projects.
When the fishery research vessel Thetis went down into 30 metres of water close to Smøgen on the west coast of Sweden in 1985, it took a substantial quantity of fuel oil down with it. Local communities soon began to complain when quantities of the oil escaped from the wreck and appeared periodically among the skerries on that part of the coast.
Miko Marine was subsequently asked by the Sea and Water Authority if its Moskito hull penetration tool could be used to remove any oil remaining in the wreck. Because Miko was too involved with other projects to bid for the work at that time, Swedish dive company Marine Works seized the opportunity to apply for the contract on the basis of using the Moskito technology for itself. The advantages offered by the Moskito for work of this type were subsequently recognised by Hav och Vattenmyndigheterna and resulted in the Marine Work bid winning and completing the contract successfully. “We are very pleased with the clean-up of Thetis to be seen as a pilot project,” said Christer Larsson at the Sea and Water authority. “The method of examining and then cleaning up the wreck by using remote-controlled underwater robots worked and the oil on board was taken care of and no longer poses any environmental risk in this delicate archipelago.” The entire remediation work on the Thetis lasted for 13 working days and was carried out by Marine Works AB with support from Miko Marine AS.
The Moskito system has now been successfully demonstrated on three separate occasions when it has been used to penetrate the oil tanks of a wreck, attach a hose and pump and then extract the oil in a single operation. This represents a huge saving when compared with conventional methods that may require the mobilisation of substantial quantities of equipment and boats and the welding of hardware onto the wreck before work can begin. There is also a real risk of oil leakage and the exposure of divers to risk during deep water recoveries.
The Swedish Sea and Water Authority has only recently published its conclusions on the Thetis project, the Moskito part of which was completed over two days in December last year. Two Miko specialists joined the Marine Works dive team aboard their catamaran and took a single Moskito to the wreck located 30-minutes from the port of Kungshamn. Diver surveys had identified the optimum penetration points on the wreck which were cleaned of marine growth by hand and by ROV to ensure a secure fixing for the Moskito’s three electro-magnetic feet. Marine Works divers had found substantial openings in the tank filling pipes through which much oil had already escaped. Nevertheless, over the following 2 days the portside aft tank and the engine room were drilled and the 730 litres of oil that remained was removed from the wreck.
The relatively small quantity of oil recovered from the Thetis contrasted with the 400 tonnes that Miko Moskitos had removed from the wreck of the Thorco Cloud in the Singapore Strait at around the same time. It nevertheless confirmed to Sweden’s Sea and Water Authority that they had chosen the most effective method for dealing with the pollution threats presented by wrecked ships.
Speaking after the completion of the project, Nicolai Michelsen, general manager of Miko Marine, said; “In addition to the ships and boats that have been lost in recent years, there is a huge number around the coasts of Europe and elsewhere that were sunk during the second world war. Many still have tanks containing heavy fuel oil and after 70-years they are now starting to decay and cause unexpected deposits of oil on nearby coastlines. It took a great deal of research and development work for us to perfect the Moskito but the success of these projects has confirmed our confidence in the technology and that of the clients who have been able to protect their coastlines by making use of it”.
Specifically in Sweden, the authorities have identified some 30 wrecks around its coastline that are regarded as high-level environmental threats. The plan is now to start recovering the oil from these wrecks as soon as possible. As an early step in this process, the autorities have invited the market to a prequalification process for a frame agreement that will be used in future projects. This process is now concluded and Miko Marine can proudly proclaim themselves as one of the contractors that have signed the frame agreement for oil recovery from shipwrecks with the Swedish Sea and Water Authority.
Miko Marine is based in Oslo, Norway, where it has become known as a design hot-shop specialising in the invention and manufacture of products ultimately aimed at preventing ocean pollution. Staffed by a small team of highly qualified designers, the company is known for its ability to find original solutions to some of the marine industry’s most pressing problems. Miko is already widely known for its magnetic patches that have been used to prevent ships sinking on numerous occasions around the world. The company also produces high-power permanent magnets that can be used in conjunction with the patches while also having innumerable uses above and below water. More recent innovations have been the Miko Fix underwater fastening system for joining metal plates without welding and a system for quickly sealing leaks in high pressure pipes.