The diagrams of ships ice propulsive quality allowing to determine all relevant parameters (power consumption, propeller RPM, movement speed and propulsion thrust) are described in the paper. These diagrams can be used to calculate above-mentioned ice propulsive quality parameters for the scenarios of high loads on propulsion system at low advance coefficients, like ice navigation and towing operations. It is pointed out that previously this calculation was impossible because of wake fractions tend to “minus infinity”. To overcome this challenge, an alternative (mooring) system of interaction coefficients briefly presented in this paper and enabling all required calculations, is developed and applied. The results of these calculations are presented in the form of ice propulsive quality diagrams that clearly and conveniently display the entire volume of the calculation data. It has been shown that ice propulsive quality diagrams can be easily added with the environmental data for usability. In the diagram given in this paper, the environmental parameter is the thickness of ice that the ship has to overcome. The possible practical applications for these diagrams, for instance ice resistance assessment during full-scale trials, are discussed in the paper. It is highlighted that the data contained in the ice propulsive quality diagrams are approximate. The possibility of using other environmental parameters is also discussed in the paper.

The development of a design and prototype of an ice floe seismic station for recording earthquakes and seismic noises in the Arctic seas, as well as the concept of its use are considered in the paper. The Arctic and Subarctic are among the key regions influencing global processes on Earth. The need for long-term seismic monitoring in the arctic and subarctic waters of Russia from ice, as well as the improvement of the corresponding equipment, is due to the great scientific interest in the complex geodynamics and tectonics of the region, the deep structure of the lithosphere, and the need to assess various geological hazards during the active development of the Arctic and the construction of critical infrastructure there. When developing the design of the ice floe seismic station, special attention is paid to a number of parameters that, according to the authors, are key for optimal long-term seismic monitoring from stationary or drifting ice. These parameters are the use of seismic sensors with an extended registration frequency range; the presence of a hydrophone registration channel; ensuring continuous monitoring of equipment and prompt data collection throughout the entire observation period; providing flexibility in the type and number of sensors used; ensuring operability at low temperatures and strong winds; ensuring waterproof of the main components of the station. The vastness of the subarctic and arctic water areas of Russia and a large list of tasks solved with the help of seismic monitoring from ice lead to the possibility of a wide application of the described equipment. Undoubtedly, the advantages of the presented equipment include its adaptability to harsh Arctic conditions, the possibility of remote data transmission, as well as the use of domestic hardware base.

The methods of using the main navigation parameters (bearing and distance) to ensure the control of the vessel movement on the planned track are considered. As the mathematical framework, classical navigation methods (determining the position of the vessel, the theory of isolines and position lines) are applied to implement the effective decisions of the corresponding parameters or their combination choice, depending on the current navigation situation. As a result, the most relevant options for choosing the leading, clearing and wheel over lines of position by bearings and distances for the planned route based on the navigation situation are identified and recommended. The expressions for accuracy estimation when using above mentioned navigation parameters and methods are proposed. The expediency of parallel indexing with errors estimation as a combination of bearing and distance as a universal variant of vessel movement control is substantiated. A new variant of the use of parallel indexing with a baseline by two landmarks as a transit line which allows to navigate the vessel in case of compass malfunctions is demonstrated. A graphical interpretation and a comparative analysis of the methods errors variation depending on the distance to the reference points are given. The recommendations and features of the practical application of methods for the vessel movement control on the planned route based on the situation of the navigation area are given. The formalization of these methods will allow the navigator, the automatic navigation complex or the control system of an autonomous ship to solve the problems of processing the corresponding navigation information at a qualitatively new level.

A variant of unmanned ship control system with obstacle avoidance in accordance with International Regulations for Preventing Collisions at Sea (COLREG) is proposed in the paper. The system consists of three subsystems: trajectory control subsystem, obstacle avoidance subsystem, course and speed control subsystem. The trajectory control subsystem generates a course that allows you to move along a predetermined trajectory. A gradient vector of the auxiliary function algorithm is used for this. In this algorithm, the alfa weight coefficient, which determines the degree of convergence of the unmanned ship to a given trajectory, is set. To ensure more efficient control convergence of the unmanned ship to a given trajectory, it is proposed to use the variable value of alfa, which depends on the condition of the coincidence of the unmanned ship course with the direction of the route and the value of alfa change for one iteration. The obstacle avoidance subsystem is based on the method of Velocity Obstacles, when all variants of the unmanned ship velocity vectors, at which a collision with an obstacle in the future is possible, are determined provided that the obstacle does not maneuver. The subsystem is activated when a dangerous situation occurs. The distance of the closest approach to the obstacle and the time of following to the point of the closest approach are calculated for identify a dangerous situation. Also, the subsystem implements a mechanism for determining the type of dangerous situation and compliance with COLREG. In total, four basic avoidance scenarios have been identified: head-on, crossing (obstacle moves to the left or right), and overtaking. To perform collision avoidance, the cost function of all variants of the course and speed is calculated, and the best variant is selected. The selected course and speed are transmitted to the course and speed control subsystem. The system is implemented in the Matlab / Simulink modeling environment. The simulation results confirmed the operability of the system, which ensures the movement of the unmanned ship along a given route and avoidance obstacles in case of dangerous situations in accordance with COLREG.

An analysis of the concrete structures state of the lower head of lock № 2 of the Belousovsky hydroelectric complex of the Volga-Baltic waterway is presented. In 1985, a crack was discovered in the concrete of the left abutment of the lock lower head. Observations for the dynamics of its development have showed that the crack size increases with time. To explain the causes of the crack occurrence and development, an analysis of concrete quality of the lower head structures is made according to the data of previous studies. Taking into account the technology of concreting during the construction process, as well as studies carried out during operation, the low quality of concrete and its heterogeneous structure have been stated. The analysis of the soils structure at the base of the lower head is carried out; the filtration regime of groundwater movement is considered. It is noted that the base soils are represented by fine-grained sands with an interlayer of loams. The presence of several aquifers in the basement soils, as well as the formation of the pressure front of the hydroelectric complex, led to significant gradients of the filtration flow. This contributed to the development of suffusion processes in the soils of the lower head base, which led to the formation of a decompacted layer in the roof of the rocks of the lower head base. The data of modern surveys of soil characteristics confirm that suffusion processes continue at the present time. This led to the occurrence of multidirectional settlement of the right and left abutments of the lower head, which, in turn, led to the development of the crack in the concrete mass. The measures taken to eliminate or stabilize the development of the crack, namely, pumping a cement-sand mixture into the soil, grouting the abutment concrete, anchoring the structure, injecting the concrete mass with a two-component synthetic resin, have not stopped the crack opening, because the main reasons such as the poor quality of concrete and the weak bearing capacity of the underlying soils of the base had not been eliminated.

The hydromorphological situation at the site of bridge construction is analyzed in the paper; the analysis results are presented. The issues of ensuring the channel geometry stability are considered. The impact of a temporary construction embankment on the f low kinematics is estimated. The level regime of the river and the channel reformations in the alignment of the bridge crossing and on the upstream section of the river are studied at the calculated level and water flow. The results obtained make it possible to determine and establish the values of the permissible degree of impact of the designed hydraulic structures and measures on the channel regime of the near-mouth section of the Zeya River in the area of the projected bridge crossing over the river in Blagoveshchensk, within which the natural and anthropogenic-induced conditions of the statistical stability of the “flow-moving channel” system are realized by the river flow. The studies were carried out in 2 stages: the first one, a test stage, was carried out for the initial everyday state of the riverbed in the section of the Zeya River in the area of the bridge crossing, according to which the model was calibrated in accordance with the specified boundary conditions in the area under study; the second one, on the model, was carried out for three options of the construction dam length, erected from the left bank to the 15th pillar of the bridge, to the middle of the span between the 15th and 16th pillars and up to the 16th pillar of the bridge crossing, which made it possible to assess the impact of the structure with different options of its length on the flow hydraulics in the area of the bridge crossing. The research method applied is the mathematical 2-D modeling of the water movement characteristics, for which the “FLOOD” software package is used.

The necessity of duplication of satellite navigation by a correlation-extreme navigation system with the actual comparability of indicators of the positioning accuracy of alternative systems is substantiated. When studying the issue of replication of the mapping standard as a basic principle of perspective navigation, the expediency of using the spline approach as an effective additional arsenal of capabilities to the list of reserved interpolating functions of the S-100 universal standard has been revealed. The phenomenon of the application of spline function methods in the framework of the implementation of the concept of modeling the navigation isosurface in order to accurately synthesize the topography of the seabed relief is considered. The theoretical substantiation of using the concept of a spline gradient in the processing of navigation information within the framework of the hypothesis of the gradient fan postulate applicability is carried out. The magnitude and spatial distribution of computational interpolation errors are interpreted into the definition of uncertainty surface, which is a two-dimensional statistical estimation of the accuracy of modeling bathymetric data by analogy with the concept of navigation isosurface. Deterministic interpolation is implemented on the basis of processing an experimental database of measurement data with further transformation into a gridded grid massif. The focus on the use of gridded data in the compilation of digital bathymetric models makes it possible to provide a detailed restoration of the underwater landscape. The interpolation gridding technology has provided a formalized structured representation of a two-dimensional grid of recorded measurements results for visualization of the navigation isosurface in three-dimensional Euclidean space. The hybrid spline algorithm is adapted to reconstruct a detailed profile of an underwater relief with the required morphological properties by mathematically simulating the plasticity of geospatial topography. Based on the technology of spline functions, the three-dimensional perspective of an isolinear bathymetric model investigated by the National Genoese Institute of the water area in the Tyrrhenian Sea is restored. A precedent for the implementation of spline interpolation together with the possibility of visualizing a volumetric perspective on electronic media for the subsequent practical use of three-dimensional electronic maps in order to increase the safety potential of navigation due to the effectiveness of visual orientation of the navigator in difficult sailing circumstances has been created.

In the context of the growing demand of developing and developed countries for oil and its derivatives, there is a positive trend in the production and transportation of hydrocarbons, mainly by sea. The combination of these processes increases the probability of environmental pollution. Moreover, the greatest pollution is associated precisely with shipping activities, when a significant amount of oil enters the seas and oceans as a result of accidents with ships. It is well known that detailed databases of oil spills are a necessary tool for realistic statistical analysis, the main purpose of which is to develop a system of methods to reduce oil and its products spills in the future. A comprehensive study of such international, national and corporate databases, as well as the analysis of the statistical data given in them is considered in the paper. Particular attention is paid to assessing the reliability of these data and their dependence on various factors. In the course of the study, methods of mathematical distribution of data with the construction of trend lines in some cases are used. Through the analysis, the fact of a decrease in the total number and volume of oil and oil products spills from sea vessels is established. It is also found that information on spills in some databases is not true, and some databases are completely closed. It is proposed to create in Russia a unified open database on oil and its products spills. Among other things, an inversely proportional relationship between the probability of an event and the damage from it is proved; small spills of oil and its products occur more often than large ones. The results of this relationship can be used in the development of models for assessing the oil spills probability and the damage.

The planning of business processes in sea transport is the foundation of transportation companies and technological projects development forecast. The calculations of business processes parameters are mainly complicated by the fact that most of the input values are stochastic ones. This is due to the specifications of technological processes and influence of a wide specter of external environment events (e. g., hydrometeorological and ice conditions) on the one hand, and market conditions (e. g., competition conditions, market agents behavior, exchange rate) on another hand. To provide the necessary level of results reliability, the calculations, that are implemented during research of specifical sea transport operations tasks (such as technological design of seaports), require to pay a great effort in experiments planning. Planning the experiments means the process of choosing the conditions, procedures and methods of experiments running. It also includes the definition of how many experiments should be provided. In other words, the purpose of experiments planning is providing the results maximum precision and reliability with minimum number of experiments. This element of research could take a whole volume in the scientific research. A method for implementing mathematical calculations with stochastic values, which allows you to define the form of the output probability distribution without Monte-Carlo method utilization, is suggested in the paper. It is proved in the paper that the output distribution is close enough to the results, which are calculated with conventional methods. At the same time, when the number of variables is small, the method requires less computational resources.

The issue of determining the reliability of the hulls of inland and river-sea-going vessels after a known number of years of operation under given condition is considered. It is accepted that fault detection of a ship’s hull is a survey, measurement and evaluation of defects in each element of the ship’s hull in order to establish the methods and scope of repairs that ensure its reliable operation until the next regular survey under specified operating conditions. It is shown that the volume of residual thicknesses can be significantly reduced using the statistical data on wear rates presented in the Rules of the Russian River Register. At the same time, the reduction in the scope of measuring the parameters of defects retains the probability of detecting all defects of the hull elements to the level of 0.95, and the probability of failure-free operation of the hull until the next survey, after the elimination of the identified defects will be at least 0.95. A form of table for processing the values of the residual thicknesses of all elements in the inspection report and instructions for filling it out are given. Explanations for using the results of measurements and calculations at determining the technical condition of certain elements in the group and the ship’s hull as a whole are given. The last column of the table indicates the method of eliminating the defect of an element and groups of elements, and in the conclusion of the inspection report, the method of repair and its scope for the entire hull of the ship providing a suitable assessment of the condition after repair are indicated. The main advantage of this paper, in difference from the previous studies of the authors in this area, is that user-friendly (the designer of the defect report tables) nomograms, which allow you to reduce the number of measurements of the residual thicknesses of hull structure elements in the online mode, have been created. The performed study, allowing you to reduce the number of measurements while guaranteeing the reliable operation of the ship’s hull, will let the shipowner to reduce the cost of repair work by reducing the number of days of ship standing on the slipway (in the dock). In addition, the ship repair company will be able to free up its production facilities for the purpose of their subsequent loading with other ship repair or shipbuilding orders, which will increase the efficiency of their activities.

The subject of the research is the tasks of assessing risks and preventing failures of ship mechanical systems, since at present reliability indicators are of great importance at the design stages and during operation. The various types of maintenance, namely, corrective, scheduled, by “state” are compared in the paper. The performance of technical monitoring can provide valid information about the actual state of the ship’s mechanical systems, which can reduce the technical and economic costs of their maintenance. A set of risks assessment methods is considered according the following stages - hazards identification, risks analysis, control options, cost-benefit assessment, decision making. To improve current methods and make them more practical, risks assessment and failures prevention are considered using the example of marine mechanical systems. The concept of risks matrix priority, taken from the analysis of the probability and consequences of failures, is used. The assessment identifies five levels of probability and five levels of consequences that can consider each type of undesirable accident. If statistical data are not available for each stage of the assessment, it is proposed to apply expert review. Possible connections between the design calculation of the reliability of ship’s mechanical systems and risk assessment based on actual data on accidents are discussed, i. e. a two-level system that considers various aspects of ensuring the reliability of ship equipment at all stages of its life cycle. The proposed approach for the joint use of risks assessment methods and traditional reliability calculations allows choosing the safest operating mode for the selected risk level, as well as predicting the necessary corrective actions, choosing options for diagnosing and maintaining ship’s mechanical systems. The conclusions received can be used to prepare specifications for the design of ship’s systems in order to assess reliability indicators, and also to extend the life of such equipment.

The project 22220 of a new two-stage universal nuclear icebreaker involves the construction of 5 similar icebreakers to work in the Arctic. At the same time, two icebreakers of this project are already in operation. RITM-200 reactor installations are installed on icebreakers. The main feature of these reactor installations (RI) is the monoblock layout of the main equipment. This type of layout should gradually replace existing since 1975 and a positively proven block layout of the reactor installation. To date, the development of new reactor installations is small and it is too early to talk about the practical results of their operation, but it is possible to discuss new technical solutions in the project. At the same time, there is a long experience in the operation of previous projects of nuclear icebreakers (10520, 10521, 10580) with a total operating time of about 400 reactor years. The received comprehensive information on the creation and operation of these facilities is a solid basis for comparing the technical solutions used on new universal nuclear icebreakers, including on the reactor installations. A methodology for comparing already known technical solutions for existing installations with new ones proposed by the designer is proposed in the paper. In this situation, the author acts as an independent expert with an assessment of the relative positivity of new technical solutions. At the same time, the assessment is carried out according to 6 comparison criteria developed on the basis of the analysis of the accompanying technical documentation on reactor installation developed by the Afrikantov OKBM. Six most important new integrated technical solutions for the modernization of the reactor installation for universal nuclear icebreakers are considered. Such an analysis is also important because an optimized power unit for low-power floating nuclear power plants is being developed on the basis of the design experience gained. As an energy source, two RHYTHM-200M steering wheels are used here. In addition, the RITM-400 reactor plant with a thermal capacity of 315 MW for the leader icebreaker with a capacity of 120 MW is conceptually similar to the RITM-200 and the differences are mainly due to increased thermal power and an increased number of energy loops while maintaining dimensions. The analysis has showed that the complexes of technical solutions mainly have a high relative positivity and take into account the latest scientific achievements and technology development.

In recent decades, the level of electrification and automation of ships has grown significantly. This is due to the increased requirements for technical, operational and technical and economic characteristics on the part of shipowners. The implementation of the requirements has become possible due to the development of related branches of science, engineering and technology: materials science, power converter technology, microprocessor electronics, and information technology. The main directions of development of ship electrical engineering and automation, namely, improvement of power generation and distribution systems, improvement of electric propulsion systems and propulsion systems, improvement of automation systems are considered in the paper. The expediency of using valve generator sets and the transition to electric power distribution on direct current is shown. Static power sources of new generation are actively developing and spreading both in industry and in maritime transport. Good control characteristics, no restrictions on the number of reverses and minimum speed, high efficiency when operating at fractional loads, high torque overload capacity on the propeller significantly expand the scope of modern AC electric propulsion systems. The desire to combine the advantages of different types of propulsion systems has stimulated the creation of combined (hybrid) propulsion systems. Combined installations incorporate a traditional thermal main engine and a propulsion electric motor. The activation of one or another engine is carried out depending on the mode of operation and the speed of the vessel. The introduction of information technologies makes it possible to automate the management and control of maintenance and repair of ship equipment. The modern development of software and hardware and algorithmic support makes it possible to create unmanned ships that can be controlled remotely and move independently (autonomously) according to predetermined algorithms, including algorithms for divergence from other ships at sea. It is concluded that the main tasks within the framework of the directions for development of ship electrical engineering and automation are increasing the energy efficiency of the process for generating electricity by introducing valve generator sets, introduction of innovative sources of electricity with high rates of efficiency and environmental friendliness, including static sources of electricity, the use of rowing electric motors with permanent magnets and inductor type, the use of combined propulsion systems with reversible electric propulsion systems, and increasing the level of automation through the introduction of information technology and artificial intelligence.