Step Ahead with Energy-Saving Design

Mitsui O.S.K. Lines (MOL) announced the launch of the pure car truck carrier (PCTC) Courageous Ace, featuring an energy-saving design (patent pending) that reflects MOL’s commitment to protecting the environment. The vessel is designed for improved aerodynamics to enhance fuel efficiency. It is the first of six newly designed PCTCs to be launched by January of next year. The Courageous Ace was launched at Minaminippon Shipbuilding in Oita. It measures 198 m long, 32.2 m wide, has a draft of 34.6 m, and displaces 57,000 GT. The ship has a cargo capacity of 6,400 standard passenger cars.

The shape of conventional car carriers makes them very susceptible to wind resistance and a phenomenon called “leeway” in which the wind pushes the vessel from the side. The Courageous Ace’s design, developed jointly with Universal Shipbuilding Corp., reduces leeway and enhances fuel efficiency. Improved fuel efficiency, in turn, contributes to energy conservation and helps reduce vessel emissions of CO2, NOx, and SOx per unit load. The new design also allows a higher service speed. The vessel’s bow is aerodynamically rounded and bevelled along the bowline to help reduce pressure from head winds. The upper deck has cargo space (called the garage deck) to maximize load capacity. The vessel also has wind channels along the sides of the vessel at the top of the garage deck, which help the ship maintain a straight course.

Test results show an approximately 20% reduction in aerodynamic pressure at the bow in winds of 15m/s. This will result in about a 4% improvement in fuel efficiency. By reducing leeway, the design is expected to improve fuel efficiency by about 6%. Together this will lead to a speed increase of up to 1 knot, depending on the direction of the wind. The vessel is also equipped with Propeller Boss Cap Fins (PBCF), a device developed by MOL to enhance propeller efficiency by 4-5 percent. Both technologies are expected to realise higher levels of fuel efficiency. MOL already plans to launch six of these new-type PCTCs between March 2003 and January 2004. Three will be built at Minaminippon Shipbuilding and three at Shin Kurushima Dockyard in Ehime. The company will continue to adopt this new design on future PCTCs.