New Shield Reduces Container Ship Resistance

Mitsui O.S.K. Lines has started demonstration tests of a new windshield for container ships that has the potential to reduce wind resistance, save fuel and reduce CO2 emissions. 

MOL jointly developed the device with MOL Techno-Trade, Ouchi Ocean Consultant, Akishima Laboratory (Mitsui Zosen) and the University of Tokyo. 

The project was backed by the Joint R&D for Industry Program, in which ClassNK promotes wide-ranging R&D activities in cooperation with industry, government and academia.

The new windshield was installed on the bow of the MOL-operated container ship MOL Marvel, and a demonstration test of its effectiveness in reducing CO2 emissions is under way.

With today's larger container ships, the height of the containers loaded on their decks has increased, subjecting the vessels to greater wind resistance. MOL recognized the need to address this issue in a cost-effective way. 

Development of the new device began with an examination of the bow's aerodynamic form through wind tunnel testing. This led to the adoption of a horseshoe-shaped design, which encloses the front line of the stacked containers to maximize the wind resistance-reducing effect while minimizing the weight of the main unit. 

The new windshield has enough design strength to meet the ClassNK rules concerning wave impact pressure. In addition, by obliquely setting the containers placed along the sides of the vessel behind the windshield, the sides of the vessel will be more streamlined, further reducing wind resistance.

With those measures, MOL expects an annual average reduction of 2 percent in CO2 emissions, assuming the device is mounted on a 6,700 TEU containership plying the North Pacific Ocean route at speed of 17 knots. The new windshield is also expected to protect ships from green water on the bow deck when sailing in bad weather.