A bulk carrier adopting NSafe Hull first in the world was launched on 2nd of August for Mitsui OSK Lines Limited. NSafe Hull (a highly ductile steel plate for shipbuilding with improved collision safety) was developed by Nippon Steel & Sumitomo Metal Corporation and adopted through the collaborative R&D by NSSMS, Imabari Shipbuilding Company Limited and the National Maritime Research Institute.
NSafe Hull has excellent ductility, while maintaining the workability (eg, machinability and weldability) of conventional steels, which substantially improves ship’s collision safety. NSSMC developed NSafe Hull through designing chemical composition and microstructural control in crystalline scale.
If a ship is made of NSafe Hull, because of superior ductility of the material, the energy absorbed before breaking hull could be roughly triple of one for a ship made of conventional steels, in case of side collision. It can therefore be said that NSafe Hull increases ship durability compared with conventional steels. Such higher safety level has been achieved by the cooperative research of the aforementioned three organizations on steel ductility and ship collision safety.
On the ship for Mitsui OSK Lines, Limited approximately 3,000 tonnes of NSafe Hull, in total, was used for structural parts where high collision safety performance was required, such as the side plates of cargo holds and fuel tanks. NSafe Hull, if used for ship’s structure, owing to its improved anti breaking performance in case of collision, contributes to preventing oil leakage resulting in environmental pollution and ingress of water into cargo holds, which directly leads to cargo damage and may result even in capsize.
Source – Strategic Research Institute