船底下抵抗板の振れ回り抑制効果について

概要

論文の詳細を見る
During the past two decades, the accident due to dragging anchor has caused concern mostly to Pure Car Carriers (PCCs) because of her huge superstructure. Drastic measure is required if such danger is to be avoided. In order to reduce the danger of dragging anchor, the growth of the transverse and rotational velocity during the yawing motion of the vessel should be controlled. The fluid resistance acting on the board attached perpendicularly to the bottom of the vessel along her keel line can be expected to control her yawing motion and thus reduce the force acting on her anchor. The effectiveness and the possibility of actualization of this "under keel vertical fin" was examined through model test and simulation. Under the condition that the 16,000 GT type PCC is moored at anchor with 7 shackles of cable under the wind velocity of 20 m/s, when the rectangular board with 1.9m depth is attached afore the midship, the force acting on the anchor can be reduced by 70%. In case of 3.0m depth, the force reduction is by 60% and in case of 4.8m depth, it reaches to 50%. It can be considered that the under keel vertical fin has the ability to achieve the safer anchoring under the heavy weather.
社団法人日本航海学会の論文
1990-09-20