| Popis: |
When a ship is anchoring in a stormy weather, the anchor often comes off due to the extreme overload of the mooring force. Then, the ship begins to run and sometimes causes aground, and this makes a serious disaster. The accident of "Toya-maru" was also one of them. There are still such accidents and lost many crew in these days. However, the mechanism of anchor mooring force in a stormy weather is complicated and not clear. Although the wind force to the superstructure becomes the major anchor mooring force, it may not be enough even if the wave drifting force is considered. In this paper, the accident of the sail training ship "Kaiwo Maru" that was caused under the stormy weather by the large-scale typhoon off Hushiki-Toyama harbor in 2004 is investigated based on the model tests. Then, it is found that the peak mooring force becomes extremely larger even in the ahead condition against wind and wave when the ship is more strongly pulled by the wind force and wave drifting force. This may causes the some kind of deadlock condition that the windlass can not pull up the anchor but the anchor begins to walk, until at last the above mentioned accident may happen in the stormy weather. |
