New Tool for Recovering Oil from Wrecks

By The Maritime Executive 03-06-2015 06:37:23

A tool for removing oil trapped in submerged vessels has been developed in Norway by design specialists Miko Marine. With the launch of the Moskito the company has addressed the pollution threat that exists with the large numbers of sunken ships around the world that still contain significant quantities of oil in their tanks as cargo or bunker fuel.

Many of the thousands of ships sunk during the Second World War now have seventy years of corrosion eating at their plates and the days are drawing inexorably closer when the pollutants that they contain will escape.

The only answers are to either seal the wreck at great expense or to recover the pollutant in a controlled manner. The new tool, Moskito, offers a third alternative. The Moskito is able to be deployed by divers or by an ROV (Remotely Operated Vehicle) to any ocean depth. Once in position outside the tank its three powerful magnetic feet are planted against the steel hull and a technician on the surface then activates a 75 mm (3-inch) diameter electrically powered tank cutter drill.

With its operation controlled through a dual video link, the Moskito’s drill pierces the steel tank walls which may be up to 40 mm (1.5-inches) thick. The cut disc then falls away inside and is immediately followed into the tank by a patented spring latch coupling that automatically connects and locks a hose to the tank without allowing any of its contents to escape.

With the hose in position a subsea pump can be activated to extract the oil at the rate of up to 12 cubic meters per hour. It is then send to the surface for safe and non-polluting recovery. The Moskito can be relocated without returning to the surface and multiple units can operate side-by-side for higher extraction rates.

The Moskito arose from a research and development project launched by Miko Marine in 2012. It quickly attracted the interest of the Norwegian Coastal Administration (NCA) which had been grappling with the same pollution problem being caused by spontaneous leaks from sunken wrecks around Norway’s coastline. Having no answer to the problem the NCA decided to support Miko Marine’s quest to find a solution and the two organizations joined forces with the backing of Innovation Norway, a government-sponsored research and development organization.

The name of the tool was the inevitable consequence of its working similarity to the unpopular insect. Just like the insect it has to be light, versatile and adaptable because when a ship settles on the seabed there is no knowing how its tanks will come to rest. However, with a visual inspection and by studying the plans of the vessel a means of attack can be found.

The Moskito is then delivered to the outside of the tank where it penetrates its skin and inserts its proboscis so that the liquid inside can sucked out. The insect allusion falls short of the engineering reality but the principle is the same and measuring just 65 cm (25-inches) by 45 cm (17-inches) and weighing only 80 kg, by subsea engineering standards the tool has an insect’s light touch.