An algorithm for the formation of a route for unmanned ship along a given trajectory and avoiding static obstacles is proposed in the paper. The algorithm is implemented by combining the trajectory motion function and the function that generates circulation around a given point (obstacle). The route of movement is defined by a set of waypoints with coordinates connected by straight line segments. The obstacle is specified in the form of the center coordinate and the radius of the obstacle. To move along the trajectory, an algorithm based on the use of the sum of the gradient vector of the auxiliary function and the vector that specifies the direction on a given route section is used. This allows the vessel to move along a given route. Circulations around the obstacle are formed on the basis of a special class of vector fields proposed in the works of D. Panagou, H. G. Tanner, K. J. Kyriakopoulos. By orienting the circulation in the direction of movement along the trajectory at the point of the obstacle and limiting it to a given maneuvering zone, a navigation vector field, which is a set of vectors showing the required direction of movement at a specific point, is formed. To reduce the probability of an unmanned ship piling up on an obstacle and to ensure safe maneuvering, an additional “repulsive” vector field, which forms a “ forbidden” zone in the navigation vector field, is introduced. The algorithms under study are implemented in the Matlab / Simulink modeling environment. The results of numerical experiments are presented for various combinations of algorithm parameters. The results are presented graphically in the form of displaying navigation vector fields showing the movement direction of the unmanned ship, and displaying obstacles, prohibited zones and maneuvering zones. Further improvement of the algorithm for solving problems of avoiding dynamic and group obstacles is planned.

The subject of the study is ice navigation, which is always accompanied by significant difficulties and dangers for the ship, its passengers and crew. The most dangerous situation that occurs if at a certain stage of navigation in ice conditions, the ice begins to move, leading to compression of the ice channel, where the ship is located, is considered. In this case, the pressure forces from the ice floes compressing the channel are applied to the vessel hull. These forces, which clamp the ship in the conditions of the ice channel, hinder its movement, contribute to the destruction of the ship hull, create a vacuum and lead to the possible death of the ship, its passengers and crew. The use of ballast pumping to prevent clamping the vessel when the ice channel is compressed by boatmasters navigating in ice conditions is investigated. It is noted that the ballast pumping allows you to deal with the “clamping” of the hull by ice to carry out movement in conditions of the ice channel compression. The advantage of its application is the independence of this procedure from other measures related to the vessel movement and the release from the ice captivity, i. e. to the vessel operation. It can be carried out together with the work of the ship’s propulsion system, establishment of ice anchors, washing the hull, etc. Other advantages can be found in ballast transfer operations that can prevent damage to the ship’s hull in the conditions of the ice channel compression. At present, the lack of a scientifically based assessment of the efficiency of ballast pumping does not allow us to determine the possibilities and advantages of these measures for a wider range of tasks in order to ensure the safety and security of ship movement in the ice conditions, especially when the ice channel is compressed. The application of a scientifically based analysis and evaluation of the ballast pumping efficiency in the ice navigation conditions is proposed in the paper. This will expand the list of vessels types that may be offered to use this method to avoid damages and their dangerous consequences when navigating in the ice conditions.

The assessment of container technologies introduction impact on the transportation of combined shipments deep into the hintreland of the sea container terminal is carried out. The consequences of transferring the main burden of bulk cargo transshipment from the seaport territory to the rear areas of railway container terminals are revealed. The mechanism of reducing the total number and further promotion of transshipment operations to the consignees warehouses gates is considered. The advantages of the introduction of new means of combined cargo consolidation, which ensure the release of heavy container and cargo movement deep into the mainland, while maintaining the advantages of container technologies, are noted. To solve the issues of resource assessment in the transport technologies under consideration, a method for measuring individual types of resources and determining the efficiency level of these resources proportions as part of a particular transport technology is proposed. The task of forming the transportation technology based on the characteristics of optimal participation of each of used in the transportation process resources is formulated. As an example of the above approach, the calculation of the number of tonne operations for different variants of the transportation organization is given. It is noted that the transfer of the main weight of the tonnage operations for the combined cargoes transshipment in a single piece form from the seaport territory to the railway container terminals (cargo stations) by organizing the transportation of such goods in heavy containers is not reflected in the reduction of the tonnage operations total number. The introduction of consolidation new means, namely, in-transit modules, capable to bring the transshipment of tare-pieced cargoes as close as possible to the consignees warehouses, is designed to contribute to this problem solution.

The proposals for adjusting the method for determining water leakages through leaks in the sluice gates and valves are presented in the paper. The methodology for leaks accounting and determining the values of infiltrated water consumptions is determined by the current “Instruction for observations and research at navigable hydraulic structures”. However, as shown in the paper, the methodology established by the current regulatory document is not free from shortcomings. The effect on the change in water levels in the lock chamber of the simultaneous processes of water inflow through the leaks of the upstream end of the lock and leakages through the structures of the downstream end of the lock is not taken into account. For a more accurate determination of the change in water levels in the chamber, it is necessary to take into account both processes and their mutual influence, that is, after calculating the filtration leaks through the downstream end of the lock, the leaks through the upstream end of the lock must be recalculated, and vice versa. A new approach to determine the leaks using an iterative calculation process is proposed. Comparison of the data obtained by calculation using two methods with the results of experiments carried out on the operating gateway № 15 of the Volgo-Don Administration is carried out. It is noted that the data obtained according to the method established by the current regulatory document give overestimated values of the water levels in the chamber in comparison with the experience. The coincidence of the experimental data with the data calculated by the proposed iterative method has turned out to be more reliable. In addition, unreliability and laboriousness of the methods for monitoring the water level in the chamber using a boat or binoculars, as recommended by the current instructions, are noted. It is recommended to use the modern technical means for measuring and processing results, which are currently available as part of the equipment of operating shipping locks.

The issue of practical application of the concept of «smoothness» in the new paradigm of isogeometric analysis for the interpolation of any navigation isoline based on the method of spline functions is investigated. It is noted that in the process of studying the problem of the exact approximation of the isoline curvature, the practical possibility of bending a planar curve in physical space with the possibility of the existence of discontinuity points is allowed. Taking into account the considered geometric effect it creates a theoretical prerequisite for the synthesis of complex navigation isolines. Variations in the solution of the task are reduced to the optimal selection of the spline modification according to the degree of «smoothness». To understand the possibilities of the mathematical resource, a comparative assessment of a typical set of spline interpolants in the form of linear, quadratic or parabolic, cubic and irrational splines is given. The advantages and disadvantages of each piecewise function are considered. The linear multi-links competing with the perspective cubic spline are interpreted as the minimum splines of the possible maximum «smoothness». The characteristics of the practical arsenal of interpolation tools are illustrated by the explanatory drawings. The cubic spline is recognized as the most preferred form-preserving phenomenon. Theoretically, the leading role of cubic piecewise polynomials in the processing of navigation information is proved. The real advantages of cubic spline interpolation are justified. The mechanism of modernization of the hybrid approximation algorithm with obtaining the effect of the speed of computational operations due to the concretized representation of matrix compositions in the development of the Schoenberg’s hypothesis is investigated. In contrast to the classical approach with the permanent calculation of each spline element, the operating with previously known numerical realizations of the matrix structure is proposed. A clarifying geometric interpretation of the probability of occurrence of a distorted navigation isoline is given when using the differential mode of satellite navigation as an alternative to the precise point positioning. The studied theoretical assumptions are confirmed by the practical creation of high-speed application programs for the purpose of «smooth» approximation of a discontinuous isoline or isosurface based on the methods of cubic piecewise approximation. The software upgrade in the proposed study is based on the introduction in the algorithm of additional logical conditions for optimal mathematical manipulation of the points of discontinuity of navigation isolines.

The influence of the container ship metacentric height on forming of conditions contributing to the occurrence of parametric rolling resonance is considered. It is noted that in the theory of ship rolling and existing methods of forecasting and taking into account parametric rolling resonance of container ships, the influence of the actual height of the centers of gravity of containers on the metacentric height, and, accordingly, on the parameters of ship rolling, is not considered. In the actual conditions of the ship operation, the rolling parameters are determined in fact, using a stopwatch and eye-measuring. The increase in accidents with the loss of containers overboard, gives every reason to consider that already at the planning stage of the ship voyage, it is critically important to know its actual metacentric height and how it will affect the rolling parameters in the expected hydrometeorological conditions. The purpose of this study is a comparative evaluation of the influence of the metacentric height of a container ship on the forming of conditions that contribute to the occurrence of a parametric rolling resonance. For this purpose, two specific conditions for the occurrence of parametric rolling, in accordance with the provisions of the circular letter of the International Maritime Organization, aimed at ensuring the safety of ships navigation in adverse weather and sea conditions are considered in the paper. The change in the actual metacentric height of the container ship is estimated taking into account the possible values of the actual height of the centers of gravity of the containers. As a result, it is confirmed that the change in the metacentric height of the container ship affects the conditions for the occurrence of parametric rolling. This is expressed in changing in the period of rolling, which depends on the metacentric height, and the period of the waves encounter, which depends, among other things, on the course and speed of the ship. It is concluded that it is necessary to take into account the actual metacentric height of the container to assess the safety of navigation in the expected hydrometeorological conditions of the voyage. It is shown how the combined change in the metacentric height, ship course and speed affects the occurrence of parametric rolling of the container ship.

The structure of the modern system of container transportation routes consisted of several interacting sub-systems whose operations are not synchronized and could not be synchronized is studied in the paper. Accordingly, the cargo transported and thus handling over between these trunk and feeder lines inevitably has to be stored at the ports of transshipment. As the consequence, the processes of cargo storage and accumulation could be regarded as a rational and efficient tool for bufferization of the flows with different parties and rhythmicity. It is stated in the paper that the modelling of interacting asynchronous shipping lines should consider coordination of the trunk and feeder routes in the transshipment ports. The model allows you to change the ships number used on a route in the consideration of the whole cargo flow system organization in order to define the necessary technological and technical characteristics of the ports. The manual experiments with the model would allow you to form the prior schedules of the trunk and feeder ships routes for the certain container flows or for the shipping lines working on the same routes or even for the certain ships. It is concluded that this approach can be used to define fair schedules, which would satisfy the participants of container shipping.A graph model of interacting trunk-feeder routes that enables to conduct the computer simulation experiments aimed at the predicting the lead-time of container shipments in the complex asynchronously functioning system of linear routes is presented in the paper. There are the results of experiments based on the actual container lines structure that prove the possibility of practical usage of the model as a tool in everyday activity of container line operators, freight forwarders, terminal operators and clients. Simultaneously a new direction of scientific researches, i. e. computer simulation of synchro-modal systems, is announced.

As global climate warming progresses, the arctic ice declines thus bringing new possibilities for arctic shipping. The new transport strategy of Russia dictates rapid growth of cargo transportation along the Northern Sea Route within the next two decades, which requires constant monitoring and assessment of sea ice dynamics in the Russian Arctic. Extensive research has been done for its western part (the Kara Sea and the Barents Sea), however scarce data is available for its eastern parts including the Laptev and East-Siberian seas. The issues of safe navigation along the Northern Sea Route are considered in the paper. An emphasis is made on one of its key seaways - the Long Strait, which connects the East-Siberian and the Chukchi seas. The aim of the research is to study variations in sea-ice concentration during the summer-fall navigation seasons in 1993-2018 and identify ice hazards for vessels transiting the strait. Sea ice dynamics is studied for both 1993-2018 and 2015-2018 periods. As source data, satellite monitoring and global ocean reanalysis databases are used. GLORYS12.v1 is preferred as the main reanalysis database since it contains the most extensive data on the Arctic waters. Its results were tested prior to the research and found adequate for the task. A consistent trend for the sea ice concentration decline has been revealed throughout the strait in the summer-fall months of 1993-2018 periods. Risks of encountering sea ice with unacceptable characteristics (as per ship ice class limitations) tend to decrease everywhere. It has been shown that August, September, and October remain ice-free, hence no ice breaking assistance is needed for ships transiting the strait during this period. Situation is somewhat different in July and November. Risks of encountering dangerous ice tend to rise when navigation in westerly direction. In July, the most favorable conditions for shipping exist along the coast of the Chukchi Peninsula. This is not the case for November, when it is safer to navigate along the southern coast of the Vrangel Island. Temporal worsening of the ice situation has been revealed in the strait in 1998-2001 and 2010-2013. During these periods ice risks increase by up to 20 % for both July and November causing minor hazards for navigation therein. No such trends have been found in the most recent analyzed period - 2015-2018. The situation, however, requires to be further monitored to predict potential ice-related hazards in the future.

The process of choosing the optimal routes for large-capacity transport vessels in the water area of the Northern Sea Route is studied in the paper. The topic relevance is related to the requirements for the implementation of the “Comprehensive plan for the development of the Northern Sea Route until 2030” and “Strategy for the development of the Arctic zone of Russia until 2035”. An assessment of the current state of the Arctic transport system and changes that have affected the composition and structure of the transport fleet is given, the issues of the construction of new Arctic ports and cargo terminals are touched upon, and the growth in the sea freight volume is given. The duration of the navigation period is analyzed, and the characteristics of the navigation-hydrographic and hydrometeorological and ice support of navigation are given. The performed analytical review of the known methods for finding the optimal routes of sea vessels has showed that all of them, as a rule, are based on the solution of two-criterion problems and relate mainly to one specific type of vessel, which does not allow using the obtained solution for vessels of different types, differing in draft and ice cross-country ability. To overcome this drawback, a multicriteria approach is proposed that takes into account the length of the route, the transition time, as well as the safety criteria associated with the possible vessel grounding or receiving ice damage. In addition, the method provides taking into account the influence of insufficient hydrographic knowledge of the bottom relief on the accident rate of ships associated with touching dangerous local seabed uplifts that are not indicated on the nautical navigational charts. The formulas for calculating particular indicators of route optimality have been obtained. As an optimal route, it is proposed to use a solution that satisfies the Pareto principle. The method is tested when choosing the optimal routes in the water area of the Northern Sea Route for ships with the ice category Arc7, the results of which confirmed the effectiveness of the method.

When choosing marine fuel, cost rather than quality is often the priority. This is justified by the presence of a fuel-processing system on the ship. Bunkering with low-quality fuel afterwards negatively affects the condition of the fuel equipment. Such equipment includes a high-pressure fuel pump, which is designed for metering fuel and controlling the loading degree of entire diesel engine. According to the statistics, about 75 % of high-pressure fuel pumps become unusable due to wear of the plunger pairs. Therefore, research of their wear causes when operating on heavy fuel is an urgent task. The research results of plunger pair state for marine diesel engines of the Hyundai Himsem H21 / 32 type, which is a four-stroke engine with gas turbine supercharging, effective power of 1860 kW, and used on ships as a drive for diesel generators, are presented in the paper. The reason for a thorough and detailed study was the inability to start a diesel engine after its continuous operation for 2800 hours at an average load of 45 %, followed by its shutdown. The grade of fuel used during this period is RMK 500 (ISO - 2041F 2010/12). For experimental confirmation of wear, high-pressure fuel pumps with new plunger pairs are installed on a diesel engine in sequence through one cylinder, i. e. the odd-numbered cylinders are fitted with pumps with new plunger pairs, the even ones are left worn out. At the same time, an uneven distribution of the exhaust gases temperature is observed over the even and odd cylinders. In addition, analysis of the fuel has showed the increased value of aluminosilicates and mechanical impurities even after separation. In the work it is shown that the presence of impurities in the fuel is the main reason for the destruction of the plunger pairs.

To implement the vector control by the asynchronous motor, it is necessary to have information about the resistance of the rotor winding, which can be significantly changed during the operation of the engine. The main reason for changing the resistance of the electrical machine windings is their heating. In addition, a priori information about the resistance of the rotor is unreliable. An error in estimating the impedance of the rotor winding leads to a decrease in the quality of control. Reducing the quality of the control consists in changing the value of the electromagnetic moment and reducing the speed control range. To solve this problem, an algorithm for identifying the impedance of rotary winding of the asynchronous motor, which allows to assess it, without resorting to complex algorithms and calculations. The basis for the implementation of the proposed algorithm is a modified vector control that uses special differential equations of the vector control. The presence of discrepancy in stationary vector control equations indicates errors in a priori resistance assessment. The special differential equations of stress residuals, which allow dynamically adjusting a priori information about the rotor resistance, as well as taking into account its temperature fluctuations during operation, are proposed in the paper. To implement this algorithm, it is necessary to obtain information about the currents occurring in the phase windings of the stator and the speed of rotation of the asynchronous motor rotor. A computer modeling, confirming the performance of the algorithm presented is completed in the paper. The rendered algorithm for estimating the rotor resistance is fairly simple in implementation and does not require large computational costs, which highlights it among other well-known algorithms. This algorithm is recommended for use in vector systems of asynchronous engines management, including powerful propulsion motors on the water transport facilities.

Development of the method of preventive control for the purposes of safe operation of the ship’s electric power system in emergency situations associated with errors of crew members when stopping generator sets during operation is considered in the paper. Special attention is paid to the development of the approach of preventive protection of equipment, which ensures the formation of a control action aimed at preventing the occurrence of an emergency situation on the ship at the time when the error has already been committed by the maintenance personnel, but the negative processes in the power system have not yet begun. It is shown that for such tasks, the decision-making time is extremely short and their solution is beyond the power of a human operator, so in this case it is advisable to use technical means that actively respond to the actions of the service personnel. For their development, a list of controlled parameters that have a significant impact on the flow of processes in the ship’s power grid in the case of an illegal shutdown of a working generator set is provided in the paper. It is shown that in the case of predicting an abnormal operation mode of a ship’s electric power system due to an erroneous shutdown of a functioning power source, two types of control actions are fundamentally possible, namely, blocking the signal for disconnecting the generator unit or disconnecting groups of electricity consumers and reducing the load on working machines. The results of analyzing the energy processes occurring in the ship’s electric power system in the case of an operator error are shown in the paper. They are provided as logical expressions for each of the control signals. Based on the obtained equations, warning signals for the technical implementation of preventive protection that excludes the human factor influence are generated. The results of the research are written as the perfect disjunctive normal form of logical functions, and the resulting expressions are minimized. Special attention is paid to the development of a new specialized algorithm for preventive control, which provides preventive protection of the ship’s electric power system from erroneous shutdowns of generator sets. A flowchart and a detailed description of this algorithm are provided. It is noted that it is necessary to take into account additional signs of the inoperable state of each of the working machines when forming the control action.