REGULATION

BV focuses on container ship springing

14 years ago

Bureau Veritas has introduced a new family of additional class notations, WhiSp, that give special attention to whipping and springing of container ships. Since the vessel’s natural frequency decreases with size and the wave encounter frequency increases with speed, large and fast container ships run the risk of encountering resonant phenomena due to the coupling of the two frequencies.

The notations testify that the vessel structure has been explicitly examined for whipping and springing. WhiSp1 covers springing-induced fatigue and is recommended for containerships between 300 and 350m. WhiSp2 adds examination of the effect of whipping on ultimate strength and is recommended for all container ships with length between 300 and 350m which are especially susceptible to whipping due to design or trade profile. WhiSp3 also includes examination of whipping-induced fatigue damage and is recommended for vessels under 350m and compulsory for longer containerships.

The advanced hydro-elastic analysis required to asses whipping and springing requires sophisticated software and applied knowledge based on full scale and model measurements. Bureau Veritas uses its Homer software which has been developed after years of hydro-elasticity research.