A Research On The Control Law Of Lateral Velocity Of VLCC During Safe Berthing On Hui Zhou Port

With the fast construction and development of Huizhou Port,the oil reserve base in Huizhou has become a national strategic reserve base in the area of Pearl River Delta,which mainly imports crude oil as oil source transported from Middle East and African.Very Large Cargo Carrier(VLCC)has become a significant ship type of international crude oil trade and transportation.The number of VLCC appearing in Huizhou Port increases year by year.The berthing of Very Large Cargo Carrier has always been one of the difficulties in pilot operation,and it also serves as a hot research issue in theory and in practice.Due to the special maneuverability and vital safety level of VLCC,the ship drivers or pilots have to drive carefully when berthing and they should also pay attention to the time node of berthing,navigation plan,tug configuration,cable mode,bow angle speed of berthing,etc.Furthermore,they will also lay emphasis on the lateral movement speed of the ship at all times so as to ensure the berthing efficiency as well as the safety of VLCC itself.In this thesis,it deeply analyzes the issues concerning the change of ship's lateral moving speed and its influencing factors when VLCC berths at No.2 berth of Huade petrochemical terminal in Mabianzhou operation area of Huizhou Port.The main research work can be summarized as follows:(1)It is analyzed in this thesis that the risk impact factors of VLCC's berthing at Huade petrochemical terminal in Mabianzhou operation area of Huizhou Port,and the safety guarantee solutions for various risk factors is also brought out,based on the natural conditions,port environment and traffic environment of Huizhou Port.(2)This thesis discusses the berthing strategy of VLCC for Huade petrochemical terminal in Mabianzhou operation area of Huizhou Port from the perspectives of channel navigation,tugboat arrangement,operation of approaching basin and berthing stage operation,hereby standardizes the berthing operation procedure of VLCC.(3)By using the method of questionnaire survey,the experience data of pilot operating VLCC to dock at Huade petrochemical terminal in Mabianzhou operation area of Huizhou pilot station are obtained.Combined with theoretical calculation,the control law of lateral velocity of VLCC berthing at Huade petrochemical terminal No.2 berth in Mabianzhou operation area under the conditions of full load,half load,rising current and falling current is concluded.In the navigation stage of the channel,the speed is generally lower than 3kn(1.5m/s)to drive through No.20 buoys.In the operation stage of the harbor basin,the tug is used to control the ship's lateral velocity,which shall not exceed 0.5m/s,In the case of half load flow,the lateral velocity shall be lower than 0.05m/s when the berthing distance is about 5m;in the case of full load flow,the lateral velocity shall be lower than 0.05m/s when the berthing distance is about 10m;in the case of half load flow,the lateral velocity shall be controlled below 0.1 m/s when the berthing distance is 15m;in the case of full load flow,the lateral velocity shall be lower than 0.05m/s when the berthing distance is about 5m;in the case of full load flow,the lateral velocity shall be reduced when the berthing distance is 60m,and the lateral velocity shall be lower than 0.05m/s when the berthing distance is 5m The degree shall be less than 0.05m/s.When the ship is close to the wharf,the lateral velocity is 0 m/s.(4)By using the equipment of pilot,this thesis records the data of a real-time berthing operation of the Panamanian ship which named "C.PROGRESS".Analysis on the actual lateral velocity of the ship berthing at Huade petrochemical terminal in the Mabianzhou operation area are carried out based on those data.The results present that the actual test data conform to the law of changes of VLCC berthing lateral movement speed obtained by the questionnaire.The results of this thesis not merely enrich the berthing control law of VLCC and help the ship drivers or pilots to master the maneuverability of VLCC ships furtherly,but also improve the safety of VLCC ships berthing in Mabianzhou operation area as well as improve the operation efficiency of VLCC berthing in Huizhou Port.