Namura develops NCF

Namura Shipbuilding in Japan recently unveiled its new energy saving development in ship propulsion, the Namura flow control fin (NCF). It claims this can save between 2-5% of energy. The company has developed NCF devices for five of its standardised ship designs. The device consists of a slender pair of narrow plate-type fins fitted to the stern section of the hull immediately in front of the propeller. By adjusting the flow of water in front of the propeller, NCF decreases the effect of turbulence, which normally causes an increase in the vortex resistance adversely affecting propeller performance. Namura checked the operational efficiency of NCF in full-scale sea trial tests on a Panamax bulker in May. These confirmed the findings of tank tests that showed energy savings of up to 5% are achievable. This amounts to a potential increase in speed of 0.1 to 0.25 knots, depending on the size and shape of the hull, or reduced fuel consumption at equal speed. Namura plans to fit NCF on all its newbuildings. It can also retrofit the NCF to existing ships. The company claims operators can recover the cost within a few years.