JUSTIFICATION AND CALCULATION OF “STORM ZIGZAGS” WHEN TANKERS SAILING
The ways to ensure the safety and effectiveness of stormy navigation of tankers in the form of “storm zigzags” are discussed in the paper. The proposed method of tanker navigation in a storm using “storm zigzags” can serve as one of the elements of restoring the sea transportation efficiency in overcoming the consequences of the COVID-19 epidemic for maritime transport. Examples of calculation and justification of parameters of “storm zigzags 60-120 and 60-130” of tankers for lateral course angles of wind and waves are given on the basis of earlier publications of the authors of this study. It is shown that the use of “storm zigzags” avoids the danger of blind sailing in the form of resonance for various types of pitching, slamming, loss of stability in passing waves, including for emergency tankers. It is noted that at the same time, the speed of the vessel’s movement in the chosen direction of movement in storm conditions is maintained. The use of “storm zigzags” can be one of the most important conditions for maintaining the rhythm of sea tanker transportation also for other types of vessels in stormy conditions, as well as ensuring the efficiency and safety of sea transportation. A universal diagram of safe and effective maneuvering of tankers in a storm, which allows you to choose a safe and effective “storm zigzag” to maintain the speed of the vessel depending on the heading angle of wind and waves, is proposed. The ways of using and correcting the universal diagram of safe and effective maneuvering of tankers in a storm by performing “storm zigzags” are proposed. The methods of storm sailing using “storm zigzags” proposed in the paper, as well as in earlier publications of the authors of this study, make it possible to ensure the efficiency and safety of tankers maneuvering in storm conditions. The use of “storm zigzags” makes it possible to choose ocean routes and maneuvers that allow solving a complex task - at the same time to ensure the optimality of the transit path, safety conditions and maintain the speed of tankers movement in the chosen direction. The conclusions obtained in the paper coincide with the available data for determining the methods of storm navigation that ensure safety and speed storage during the vessels passage along a given path. The results of this work can be used to develop methods for ensuring safety, maintaining speed and running time when sailing in a storm, taking into account the characteristics of tankers and other types of vessels.