The Effect of Bulbous Bow on the Probability of Slamming on Hull (Case Study on Container vessel 4200 DWT)

One of the environmental factors that influence the probability of a ship accident is the wave height. Extreme wave height can cause the bow of the ship crashing on the surface of the sea water (slamming). Slamming can cause local buckling and deformation on the ship's bottom plate at the bow. At certain conditions the slamming can cause damage to the ship's bow structure. This research discussed the effect of using bulbous bow on slamming probability on 4200 DWT container vessel. The analysis was carried out at 1.5 - 3 meter wave height conditions, according to the wave height conditions on this ship's shipping route in Makassar Strait. The geometrical dimension is LPR = 2.116 m, BB = 2.805 m and ZB = 2,42 m. The analysis of the motion response of the ship is carried out on two types of motion heaving and pitching. In maximum draft conditions, 5.5 meters and speed 11.9 knots (6.12 m/s) and a heading angle of 180°. The next step is calculation of response spectrum by multiplying the wave spectrum with RAO. From the analysis, known that higher wave produced greater response of heaving and pitching motion. And also higher wave produced higher relative bow motion spectrum. The probability of slamming of 4200 DWT ships with bulbous bow is smaller than without bulbous bow. At a certain wave height (2-3 meters) indicates that the bulbous bow reduces the slamming probability approximately 17-49%. The intensity slamming per hour of 4200 DWT ships with bulbous bow is smaller than without bulbous bow. It is indicates that the bulbous bow reduces the slamming intensity per hour approximately 24-45%.