Analysis Of Factors For Affecting Anchoring Safety

Vessel drops anchor in the anchorage,when she is under quarantine,waiting tide, barging or heavy weather avoidance,so anchoring is the important part of the ship's operation.Because anchoring safety is related to the security issues of the person,the vessel and the cargo,experts and scholars have been concerned about anchoring safety issues,and make a lot of research work.The purpose of these efforts is to improve the safety of anchored vessel to guide the production of safety of vessel.In this paper,a more detailed analysis of factors of the influence on anchoring safety is made,and the safety of 10,000 dwt vessel riding at single anchor is discussed. Weight and fuzzy subset of membership degree of factors defined are acquired by means of AHP and surveys.With the application of fuzzy comprehensive evaluation method,the mathematical model of anchoring safety evaluation is established,and importance level of factors on anchoring safety is acquired.Finally,this paper analyzes the safety of two vessels' anchoring with the application of evaluation model established in this paper,and the result is more in line with the actual situation.The study has obtained the following conclusion:(1) Among the 16 anchoring safety factors in this paper,sediment,anchor holding power coefficient,water depth,chain scope,wind,current is the several factors that are more greater impact on anchoring safety.Current is greater than wind under full load condition,while wind is greater than current under ballast condition.Anchor equipment condition and age of the ship also occupy a certain proportion,which requires persons on board should do a good job to make the equipment in good condition in the maintenance of shipboard equipment.(2) Captain,which is second only to sediment and anchor holding power coefficient in combined weighting ranking,is also very important for the safety of anchoring.The factor of the captain contains maritime experience,command decision-making ability and mental state.Maritime experience of captain is very important.(3) 10,000 dwt vessel should choose the anchorage depth which is between 2d and 1.5d+2/3H_max;Wind above 7 has a greater impact on anchoring safety,and need more attention.The research provides a reference for marine navigators on anchoring safety.