Japanese shipping firm Nippon Yusen Kaisha (NYK Line) took delivery of a new coal carrier last month. The vessel has been equipped with what the company claims is the world's first "innovative air-lubrication system."
The vessel, named 'Soyo', was jointly developed with Oshima Shipbuilding and features a "main engine scavenging air bypass" that uses bubbles to reduce the frictional resistance between the ship's bottom and the seawater.
NYK believes the 'Soyo' is only the third vessel to be equipped with such a system, following the two module carriers 'Yamatai' and 'Yamato'. The company further claims the 'Soyo' will be the world's first vessel for overseas transport to have an air-lubrication system permanently installed.
The module carriers 'Yamato' and 'Yamatai' both have a shallow-draught hull that was deemed potentially suitable for an air-lubrication system, and the system was subsequently installed on these vessels to verify the system's effectiveness.
NYK states this latest installation on the 'Soyo' is to verify the effectiveness of the system on a coal carrier with a conventional deep-draught hull, so that the range of applicable merchant vessels benefiting from the system can be expanded.
This newly installed air-lubrication system is believed to reduce CO2 emissions by taking some of the main engine's "scavenging air" (also known as "combustion air") from the main engine's turbocharger and leading it to the vessel's bottom to reduce the frictional resistance between the vessel's bottom and the seawater. A system featuring this scavenging air bypass is expected to effectively reduce CO2 even on large vessels having deep draughts.
NYK states that during sea trials, the safety and performance of the system was verified, confirming an approximate reduction in CO2 of four per cent during deep draughts and an eight per cent reduction in shallow draughts.
After the vessel is delivered, tests will be conducted during marine transport to confirm the reduction and assess the performance of the system.
In cooperation with Japan's National Maritime Research Institute, the system was jointly developed by NYK, Oshima Shipbuilding, and the Monohakobi Technology Institute, an NYK Group company.
The project has been subsidised through Japan's Ministry of Land, Infrastructure, Transport and Tourism's "Support for Technology Development from Marine Vessels for Curtailing CO2" project.
The NYK Group concludes that it will "continue to encourage initiatives that address climate change by striving to install this system on other types of vessels."
