The Study Of Safety Zone When LNG Ship Entering And Leaving Port

With the liquefied natural gas playing a more and more important part in the energy structure, it’s safety problem becomes more notable, the LNG is imported mainly by pipeline and ships. As to the nature of LNG, the LNG ships are of technical、 difficulty and value added. Each port takes many measures to make sure the safety of LNG ship, including escort, keep clear, setting protecting zone and so on. There are kinds of protecting zone to make sure the safety of ships and facilities. Safety zone is to protect LNG ships underway and berthing and departing. Security zone is to safeguard form destruction、loss or injury form sabotage or other subversive acts, accidents or other causes of a similar nature. And isolation zone is to insulate the person from the hurt of leakage, explosion and vapor cloud. The study object of this thesis is the range of safety zone, with the purpose of environmental and safety.With the purpose of safety navigation and reduce the disturbance of other ships around, the thesis analyses the range of LNG ships. The thesis summarizes kinds of elements, and analyses the elements using the weighting process system. The thesis analyzes the human factor、 the natural environment、the ship and the traffic environment. The result shows that the human factor has limited effect on the safety zone. But the natural environment、the ship and traffic environment have the major effect. Then the thesis take the size、the speed、water depth、and traffic density as the major parameters, and chooses the proper method to calculate the range of safety zone separately in longitudinal and lateral.When calculating the range of safety zone, due to the limitation of shipping lane, the thesis uses the stopping ability theory and vehicle-following theory, to make sure that there is enough distance for the ship to buffer. As to lateral distance, considering the interference of other ship,article gets the result by the theory of interference force between ships.Finally, the thesis gets the different kinds of safety zone for different type of LNG ship, and put forwards some suggestion to make sure the efficient of safety zone.The result has a certain theoretical and practical value.