Research On Navigation Condition And Key Technologies To Security Of VLCC In Bohai Sea

With the development of the maritime economy of the Bohai Sea region and the exploitation of local marine resources, especially the increase of the dependence on overseas oil resources, the number of oil carrier navigating in the Bohai Sea is growing more and more, at the same time, very large crude oil carrier ( VLCC ) has begun to enter the Bohai Sea and exit frequently. The emergence of VLCC has brought new challenges to the navigational safety situation of the Bohai Sea.The restricted factors of ships' navigational safety in the Bohai Sea are mainly: the inadaptability of navigational depth and the development of large-scale ships, as well as the increase of ship traffic flow, and the delineation of the original route has been unable to meet the growing demand for ship traffic; The disorder of traffic between ships in the convergence area of the main traffic flow has become the main reason leading to the accident; Single VTS monitoring function can not meet the regulatory requirement of ships' safe navigation; The special meteorological conditions of Bohai sea brought a serious threat to the safe navigation of ships and otherwise. The combined action of the above various factors have brought a serious threat to the safe navigation of ships, especially to VLCC.Against this background, the paper conducts a monographic study on the key technical aspects of navigation conditions and safeguard of VLCC in the Bohai Sea, the main research contents include:(1) The investigation analysis of vessel traffic flow in the Bohai Sea and the navigation environment based on the natural conditions, AIS data and the questionnaire, furthermore, in accordance with the results of traffic survey the paper reaches the main problems existing in the navigation safety in the Bohai Sea.(2) The under keel clearance (UKC ) research on VLCC navigating in the Bohai Sea based on the analytical expression and empirical formula. Analyzing the main method of obtaining UKC, the paper presents a new calculating method which is based on the analytical expression and empirical formula combining empirical value to calculate the UKC of VLCC in the Bohai Sea. (3) Discussing the significance of VLCC's speed control in the Bohai Sea, meanwhile, the paper sets forth the influence factors of speed control that should be considered, puts forward the main ways to control speed, and defines the speed control values of VLCC sailing in the Bohai Sea.(4) In the above study, based on the existing ships' routing and the characteristics of VLCC, the paper designs optimization route of VLCC sailing in the Bohai Sea.The results of research topic provide a powerful technical support for improving the maritime regulatory approach of the sea area, for optimizing the navigation environment of VLCC sailing in Bohai Sea and for ensuring the navigational safety of VLCC, besides have great significance in guiding to promote the economic development of the Bohai Sea region.