Guidelines - YP47 Steel for Hull Structures
The first large sized container carrier in the world to use a new grade of higher tensile steel in its hull structure with a specified yield point of 47 kgf/mm (460N/mm) was built to NK class and delivered in June 2007. Known as YP47 steel, this comparatively strong and tough material is currently attracting much attention as an effective solution to the challenges presented by the use of extremely thick steel plates in the construction of the hull structures of container carriers that have been growing ever larger in size in recent years. ClassNK prepared these guidelines drawing upon the results of many years of research conducted into the practical application of YP47 steel and the experience gained from actual use of the material in the construction of large size container carriers.
Harad
Harad is the first in a four-ship double-hulled series of VLCCs constructed for Hellespont of Greece by the South Korean builder Samsung Heavy Industries. During construction, the four vessels were re-sold to NSCSA of Saudi Arabia. The vessel, which incorporates a number of technical features to ensure high levels of environmental protection and high performance, holds a large main engine, improved strength by increased plate thickness, improved service lifetime for coatings by increased paint specification and advanced inert gas system. The hull form of the vessel has been specifically remolded to meet Hellespont's requirements and differs from the conventional VLCCs, featuring a 'blunt' fore part and a breadth of 190 ft. (58 m) to reduce hull deflection.
