한국 근해 대형 선망 어선의 복원성과 횡동요 특성

Abstract

It is basically necessary for master and ship mate to grasp the inherent stability of their ship, and in addition, ensure that the ship complies with the minimum statutory standards of stability. But it is not so simple task in small fishing vessel to do this work adequately. They know of GM is an important criterion in the stability, but significant factor in stability is not only the value of GM alone, but the righting lever GZ should be assessed correctly, even if the process of deriving and evaluating it are often difficult and time consuming task. Information of ship's stability shall be based on the determination of stability taken from an inclining test carried out, and to be provided for the master after the test. And since ship's stability can mostly take notice in rolling, stability and roll motion of a ship may be the most critical factor in defining a vessel's survivability. From this points of view, the aims of this study are to realize the stability of the offshore large purse seiner in Korea by the inclining test data and some calculations, and learn the roll characteristics of the ship receiving transverse wave by carrying out the water tank test. The author compared the stability of the ship with IMO criteria and domestic rule of stability, and on the other hand, analyzed the roll characteristics of the ship with varying the loading condition, rolling reduction installation, wave height and wave period. The results are summarized as follows; 1. The values of GM with varying the loading condition satisfy all of the IMO criteria and domestic rule for the stability, but both case of the area under the GZ curves between the heel angles of 30？ and 40？, and the heel angle occuring the maximum righting lever at the fishing ground departure and arrival condition in the hauling net situation not satisfy the IMO rule. 2. It were found out that the initial metacentric height of the ship is very large, but the range of stability and the occurring angle of the maximum GZ are very small. 3. Maximum dynamic moments are 3.48(ton․m) and 6.78(ton․m) at F.G arrival and F.G departure condition in hauling net situation respectively. 4. The rolling angles of the model were increased with increasing of wave period and height, especially around on the natural wave period of her. That trends were more distinguished in the situation of bilge keel installed only than in the stern keel installed additionally. But the rolling resonance of her was not proved perfectly. 5. Stern keel has not noticeable effect on the reduction of the roll in the light ship condition, but has a little effect on it in the full load condition. 6. When analyzing the rolling characteristics of small fishing boat, it need to consider the displacement, wave period and wave height comprehensively for understanding the mechanism implied more accurately.