Bubble power

The air hull lubrication system enables a reduction in a ship’s through water frictional resistance by creating a carpet of bubbles underneath the hull.

Although the idea is far from unique or new, one pioneer of a variation of the system called the Air Cavity System (ACS) technology is the DK Group which has been working closely with Lloyd’s Register to bring the new technology to market.

It says that the system reduces a vessel’s fuel consumption and CO2 emissions by up to 10% – providing huge cost savings for ship owners and reducing the shipping industry’s impact on global warming. The group also points out that it has a 18 to 30 month return on investment.

ACS works by using compressors to fill a series of cavities with air fitted to the leading edge of the flat bottom of a vessel. As sea water flows past the still air in the cavities, it draws micro bubbles out of the chamber, which then form on the hull. This in effect makes the vessel float on a thin layer of air bubbles helping to eliminate resistance and enabling it to travel more economically on any given route.

DK says that this technology is best suited to tankers, bulk carriers and broad-beamed container ships. It can be fitted to both newbuilds and retrofiited to existing vessels.

The company plans to trial the system in December 2013 on a 45,000 dwt Handymax tanker.