In order to ensure the safety of the LNG (Liquefied Natural Gas) carriers' navigation in two-Lane channel, a method based on risk acceptance criteria to calculate the width of two-Lane channel is proposed. First, the collision probability and risk quantitative calculation model is adopted to obtain the risk acceptance criteria of LNG carriers when they navigate in two-Lane channel. Then according to the traffic and environmental characteristics, we calculate the risk and collision probability of LNG carriers being crashed by passing vessels during their navigation; and calculate the minimum distance between LNG carriers and other vessels with a qualified collision probability or acceptable range of collision risk. The larger value is selected as the width of LNG carrier safety zone. Finally, the width of two-Lane channel according to the width of LNG carrier safety zone is obtained. The method can shed light on similar engineering design.
The imbalance of distribution of natural gas among different continents leads to the prosperity of the LNG transport market. With the development of LNG mining and transportation technology, more LNG carriers are needed in on-water transportation market. As a result, LNG navigation puts great pressure on the safety of navigable waters. And at the same time, higher requirements for navigable width of two-Lane channel are put forward. At present, there are many standards for channel width design both here and abroad, for example Site Selection and Design for LNG Ports and Jetties(SIGTTO, 1997), Code for Design of Liquefied Natural Gas Port and Jetty(JTS 165-5-2009, 2009), etc. The channel design for LNG carriers is still in its infancy, Liu and Chang believed that with the development of large-scale ships, the influence of the speed should be considered when designing the width of the channel(Liu et al, 2007). Xiao mentioned that the human factors in ship navigation must be considered in the design of channel width, and the corresponding algorithm was then put forward(Xiao et al, 2002). Zhang studied whether it was safe for large ships entering and leaving Caofeidian port area by calculation, based on mathematical model and theoretical analysis. In this paper, a calculation method of navigable width of double-line channel based on LNG width of ship navigation safety zone is proposed(Zhang et al, 2009). By means of risk quantification calculation of LNG carrier navigating in two-Lane channel, the width of ship safety zone is determined which meets the requirement of the risk acceptance criteria for s. Then, according to Code for Design of Liquefied Natural Gas Port and Jetty, the width of two-Lane channel can be obtained. This method can shed light on waterway design and waterborne traffic management.
