A Danish invention that has the potential to save 15% of a ship's fuel consumption has been approved for commercial use, writes professional journal Ingeniøren. The German classification company Germanischer Lloyd has approved the Air Cavity System (ACS) of the Danish-Dutch company DK Group for commercial shipping, and has entered an agreement with DK Group to install ACS in a number of new ships.
Driving a container ship or supertanker across the oceans takes a lot of power and uses a lot of fuel, much of which is expended in overcoming the frictional resistance between the hull and the surrounding water. If the friction can be significantly reduced, a lot of fuel can be saved. ACS is, very briefly described, a carpet of air pumped into an elongated cavity under the hull, which enables the ship to glide more easily through the water. Less friction, less fuel consumed.
Prior to the agreement with Germanischer Lloyd, DK Group has spent three years developing and testing the ACS system on a multifreighter in a Norwegian fjord.
MD of DK Group Christian Eyde Møller told Ingeniøren: "Naturally, it means a lot to us that an established, industrial big player like Germanischer Lloyd supports this project. We have already proved that the ACS technology works. With the certification from Germanischer Lloyd we can also get it implemented in new ships."
DK Group's calculations show that ACS reduces a ship's friction by approx. 10%, which gives fuel savings of 10-15% for bulk carriers and tankers, while for container ships the figure is just under 10%. If the ACS technology is combined with more effective propellers and helm systems, as well as better reuse of waste heat, the fuel savings, and thus the reduction in CO2 emissions, can be as much as 30%.