Reducing emissions with ‘air lubrication’

One of the most efficient ways to lower emissions from ships is to reduce the energy used to push the vessel through the water. By applying air lubrication – resembling an “air carpet” – we can reduce the resistance between the ship's hull and seawater using air bubbles, creating energy-saving effects.

Air lubrication is a promising technology that can help vessels reduce emissions.

Air bubbles - water

The air lubrication technology is offered by various vendors and is based on onboard air compressors, pushing the air through tiny nozzles, releasing a vast amount of air bubbles. At DFDS, we are looking into which vessels to retrofit with the new technology. Finding suitable vessels requires thorough investigation and installations specifically designed for each ship. For the technology to be efficient, the bubbles must stay below the bottom of the vessel for as long as possible. This makes large ships with flat bottoms best suited. We also need to pay special attention that bubbles reaching the rudder and propeller do not generate new issues, such as reduced propeller efficiency or increased underwater noise levels.

DSC 3868 Man working with steel

Installing the technology requires an extended stay in drydock, which generally only happens once every five years. During these stays, we will cut holes in the hull, weld in the nozzles, grind the welding seams to make the hull surface smooth, and then repaint the ship. New electrical cables must be installed inside the vessel and special air intakes designed.

We estimate that about a third of our existing fleet will be suitable for retrofitting with air lubrication technologies over the coming years, pending the conclusion of our studies.