Resistance of Fishing Ship That Based On Bitung Coastal Area

The type of fishing vessel that is widely used by fishermen in North Sulawesi, especially in the Bitung Coast, is a pelagic fishing vessel. When the ship sails at a certain speed, it will experience resistance in the form of resistance. This resistance will cause some speed drops. This will result in losses to the ship, including the time it takes when the ship performs maneuvers to catch schools of fish, extending the sailing time so that fuel consumption becomes greater and the use of working hours becomes longer, which means the cost of exploitation of the ship becomes greater.

The purpose of this research is to study the resistance of fishing vessels and to explain the impact of the coefficient of vessel shape on vessel resistance and after being given various treatments.

From the results of this study, it can be explained that the beam coefficient (Cb) of the ship model in Bitung Coast which was treated with trim is 0.54 which means that the volume of the submerged in the water column is 54 of the volume of the ship in the form of a beam. Thus, the ship's body tends to be thin/slim, so that when the ship is run, the ship does not get too much detention.

Likewise, the prismatic coefficient (Cp) for the ship model in various trim variations is 0.72 which means that the displacement volume is 72 percent of the volume of the ship model as the product of the cross section of the middle of the ship with the length of the ship, the ship model has a tendency the cross section towards the bow and aft is increasingly equal to the cross section of the center of the model ship. For the coefficient of the middle cross section (C_Ä) of the ship model in various trim variations is 0.60, which means that the middle sectional area of the ship model is 60 percent of the cross sectional area of the ship model in the form of four squares. From the average value of the coefficient of water field (Cw) for ships in various trims is 0.79 which means that the area formed by the water line in various trim variations for ship models tends to be close to a rectangular shape. This also shows that the opening of the ship's wall from the stern to the bow is getting smaller.

The total resistance of the ship model (RTM) is small as well as seen from the different trims, which start from trim -1º, 0º, 1º, 2º from the lowest speed to the highest speed. The frictional resistance for the model vessel at various trim variations for all current speeds shows that the value of the frictional resistance of fishing vessels is small as seen from the wet surface area (S) as well as for the residual resistance.