Jasper Boessenkool, head of strategic R&D for Maersk Maritime Technology spoke at a media gathering at Maersk’s headquarters in Copenhagen where he admitted that they were unable to verify the efficiency savings after the trial run. He is quoted to have said: “The balance is how much energy do you need to create these bubbles and how much do you save? And how you create a stable boundary layer (of bubbles) on a ship?”
Maersk had a 3000 teu, 240 m long container ship retrofitted with compressors connected to 2 km of piping in the hull to 124 openings to create an air lubrication system on the bottom and sides of the hull.
Even though it proved to be efficient during lab tests, Mr. Boessenkool explained: “The only problem is we couldn’t really verify the savings. We sailed it with the system on and off but we really couldn’t find the saving. Despite Maersk’s failure to verify savings the concept is still being explored by a number of other companies. It’s not that because of the pilot and trial we did the technology is dead, there are still quite a lot of people investigating and creating various ways of creating this micro –layers of bubbles.”
While Maersk’s approach was to use both sides and bottom of the hull, yet other companies are trying out different approaches. Mr. Boessenkool added: “There are systems now that focus completely on the flat bottom where it is a little bit easier in theory that the bubbles actually stay there. We couldn’t find the balance between the energy we put into creating the bubbles and the energy we saved.” he concluded.
How does Air Lubrication System works?
The Air Lubrication System works on the simple principle of trapping a layer of air bubbles beneath the ship’s hull. An air blowing system is used to create air bubbles that are passed continuously beneath the ship’s surface. Outlets for air bubbles are created symmetrically on both sides and the bottom of the hull. Air must be blown at a constant rate to continuously replenish the lost air bubbles to ensure a uniform layer of bubbles are maintained at all times. This helps reduce the drag and water resistance as the ship is in motion. Tests have shown that a container ship fitted with air lubrication system can offer reduction in CO2 emission of up to 35% as compared with conventional container ships.
Source: Maersk
