Influence Of Safety Interval Between Ships On Throughput Capacity Of Coastal Fairway

With the rapid development of port industry, the capacity of some coastal fairway has reached a saturation point. In the mean while, the condition of water transportation is getting worse increasingly, which has gradually become the restrictive factors of port development. Safety interval controlling the trailing distance between arrival or departure carriers, is the one of important quantity indexes evaluating the safety level of fairway, and has direct impact on security and throughput capacity of coastal fairway.Firstly, we summarized the background and expression method of presently used safety interval and its advantages, disadvantages and applicability based on the theory of ship domain. Then the ship-following model with the fully consideration of relevant factors such as vessel type, ship maneuverability and dangerousness of port's goods is proposed, from which the equations of safety interval under different safety condition levels are specified respectively. Meanwhile, according to actual procedure of coastal port navigation operation system, a simulation model of fairway throughput capacity is established based various types of safety interval.To analysis the effect of the safety interval on throughput capacity of coastal fairway, the paper focuses on the multiple navigation conditions and chooses the combinations of the main factors. Then the conception and calculation method of influence coefficients of safety interval are given out, while the ideally fairway throughput capacity is taken as the criterion. Through sensitive analyzing of the simulation results, the variation of the effect of the safety interval on throughput capacity is discussed. At the end of the dissertation, both of the simulation results and the relevant conclusion are validated through analysis of some examples. Additionally, the recommended safety interval is also proposed in parallel comparison of all the types of safety interval.From all above, this research preliminarily explored the impact of safe interval on the throughput capacity of coastal fairway, which can be applied as a theoretical reference to the planning, constructing and operating of the coastal fairway.