A method of the calculation of vessel dead reckoning coordinates with the accuracy assessment is proposed. It is based on previously derived formulas for the assessment of the uncertainty boundaries for vessel geodetic latitude and longitude during its motion along the ellipsoid surface. The above formulas are used as follows. At first, the latitude and its precision index are calculated. After, they are used for the calculation of the longitude and its precision index. As the result, it is possible to determine uncertainty intervals for vessel coordinates derived with dead reckoning. The implementation of this method for testing an electronic chart display and information system Navi-Sailor 4000 as to the calculation of vessel dead reckoning coordinates with it is shown. The provision of the information about vessel heading and speed through water is carried out to the system in real-time mode by means of a signal simulator. The speed and heading are remaining unchanged during one-hour time interval. During the above time interval, the data about dead reckoning coordinates are recording into a log-file, then the data are converted in a text format and used for the test. The dead reckoning coordinates, calculated by the system, are in the limits of uncertainty assessed with the proposed method. A limitation of the method is that it does not take into account the influence of errors due to rounding because of the finiteness of the computer bit grid. After the elimination of the above limitation, it seems to be possible to use a modernized version of the method as a part of a procedure for testing the navigational systems which give the information about vessel dead reckoning coordinates.

This article analyzes and compares the effectiveness of two algorithms for collision avoidance in groups of autonomous vessels: one based on geometric analysis of vessel approach and cost function minimization for calculating a safe maneuver (traditional algorithm), and an algorithm utilizing a neural network. Both algorithms assume external control of a group of vessels within a specific area using a vessel traffic management system and coordinated maneuvering of dangerously approaching vessels. Descriptions of these algorithms are provided along with their simplified block diagrams; to solve the task of safely maneuvering a group of vessels, a sequential analysis of all possible vessel pairs in the group and changes in their courses is proposed. The process of creating three test datasets is described, two of which were generated using a program and included 100 scenarios each, while the third was manually composed and included 30 scenarios for different vessel group approach variations. During the testing of the neural network algorithm, two neural networks trained to predict safe courses for vessel pairs were utilized. The neural network used in the algorithm, trained on 743671 samples, allowed the processing of test vessel approach scenarios with an accuracy comparable to the traditional algorithm. Depending on the number of dangerously approaching vessels in the area, the neural network algorithm processed test scenarios 2–14 times faster than the traditional algorithm. The paper highlights the limitations of the described algorithms and outlines planned improvements for subsequent research, including the optimization of the safe maneuver selection methodology and further training of the neural network on larger data volumes.

The paper considers a method for solving the problem of dynamics of forced vibrations of a wall line based on a model of an equivalent elastic two-stage rod with a pliable connection of sections. The model is represented by a system of partial differential equations. The solution of the equations is obtained by the Fourier method for eigenfunctions orthogonal with weight. It is established that the presence of an elastic element at the junction of the sections does not affect the orthogonality of the eigenfunctions. The influence of the elastic coupling compliance coefficient on the natural frequency spectrum of the shaft line is estimated. The obtained forms of natural vibrations of an equivalent elastic two-stage rod are consistent in appearance with the corresponding forms known in the literature for a discrete model of a similar torsional circuit. A partial solution of the equations is found for the case of the action of the harmonic load on the engine and the averaged torque on the propeller. As an example, the dynamics of forced vibrations of the shaft line of a barge of the Sosnovka type is studied. The results of calculating the natural frequencies of the considered model are compared with the classical discrete mass method. The analysis of the obtained plots of the twisting angles and torques showed that the angles are satisfactorily approximated by the first proper oscillation shape, and for moments, high shapes must be taken into account. The comparison of the simulation results with the data of the torsiogram obtained under production testing conditions indicates the need for further development of the model. Further improvement of the torsional circuit, as well as a more detailed study of the nature of the operating loads, are considered as promising areas of research.

In the literature exist data about the hydrodynamic characteristics of propulsion systems, which include a duct and a fixed-pitch propeller with a truncated blade shape (Kaplan propeller), which has a relatively small blade-area ratio of 0.55. Usual such propellers has a very high loading coefficient, which entails the need to increase propellers blade-area ratio in order to prevent the occurrence of developed cavitation. The article presents the results of the first stage of research, which included testing a series of four-blade truncated propellers with a blade-area ratio 1.0 in free water. The tests were carried out in the towing tank of Admiral Makarov State University of Maritime and Inland Shipping on experimental installation, which include a special hydrodynamic stand. A series of tested propellers were 3D printed from PET-G plastic. A preliminary assessment showed that the chosen diameter of the models will ensure the achievement of supercritical Reynolds numbers at a rotation frequency of about 20 s^–1. However, during the tests, it was found that the rotational speed must be increased to 30 s^–1, which, in turn, led to a reduction in the test program due to the regime limitations of the experimental equipment. Nevertheless, the analysis of the test results made it possible to build a “hull” and “machinary” diagrams according to the Papmel form. An assessment of the strength of the models was carried out, which showed that the stresses arising in the root of the blade are significantly less than the allowable ones. The obtained results expand the design possibilities of Kaplan propellers with water-jet propulsion units, as well as a part of the “propeller-nozzle” propulsion complex.

To ensure the product life cycle (PLC), foreign and domestic information technologies have been developed that mainly ensure the stages of design and manufacture of products, but they do not allow for automation of the design of technologies for restoration and strengthening of parts. The relevance of restoration of critical parts of ship equipment is due to dependence on foreign supplies of equipment and spare parts (SP), as well as sanctions from unfriendly states, which complicated the acquisition of SP, and the need for import independence arose. The paper shows that life cycle management of a restored part has a significant impact on the efficiency of marine fleet operation, and provides stages and main sub-stages of the life cycle of restored parts of ship equipment. Restoration of parts is considered appropriate if the required durability and savings are ensured compared to manufacturing or purchasing a new part. The concept of life cycle management of restored parts is provided. Life cycle management of restored parts includes planning, control and management of all stages, as well as decision-making to ensure the durability of the part through the use of advanced materials and coating formation technologies. The stage of the life cycle of the restored part, determining the service life of the part, the economic efficiency of its restoration and subsequent operation, is the technological process that ensures the optimal chemical composition, mechanical and structural parameters of the coating. All the properties of the restored part are laid down at the stage of designing the technological process. The prospects of using the life cycle management of the restored part are shown using the example of restoring precision parts of the fuel equipment of marine diesel engines. The use of various technologies for the same type of restored precision parts allows obtaining coatings with different chemical composition, mechanical properties, structure and, accordingly, different values of durability and cost price to ensure the specified service life of the tribological unit at an acceptable price.

In projects of floating facilities with a nuclear power plant, great importance is attached to the formation of a set of properties of the internal self-protection of the reactor, i. e. the development of properties that ensure its safety based on natural feedbacks, processes and characteristics. To do this, the RU project is based on physical patterns and technical solutions that prevent or minimize possible consequences from emergency situations. In particular, the natural circulation of the coolant in case of loss of power supply by the circulation pumps of the first round allows cooling the core after its transfer to a subcritical state. However, in order for a natural circulation to occur sufficient to ensure nuclear and radiation safety, certain conditions must be met in a particular case. The paper notes that the most important property of reactor installations of nuclear vessels is their ability to ensure natural circulation of the coolant in emergency situations, as well as when operating at capacity. This makes it possible to reduce the dependence of reactor plant safety on the technical condition of power supplies. Currently, natural circulation of auxiliary cooling media in passive safety systems is also widely used in reactor installations. These include emergency reactor cooling systems using an emergency cooling system, including using intermediate heat exchangers; reducing emergency pressure in the protective shell in case of an accident with a large coolant leak; cooling the reactor vessel in an out-of-design accident with the formation of corium. The paper proposes a method for preliminary analysis of the reactor plant’s ability to ensure natural circulation of the coolant, which allows us to compare various design solutions that contribute to an increase in coolant consumption during natural circulation. It is shown that for the operation of the reactor plant in stand-down mode and at energy power levels with natural circulation of the coolant, it is advisable to switch to boiling reactors. Passive safety systems using natural circulation have received special development on new nuclear vessels of projects 20870, 22220, 10510. Further development of safety systems using natural circulation to move cooling media is predicted.

The article is devoted to the actual problem of insufficient energy efficiency of combined internal combustion engines. One of the directions of its solution, which became the goal of this work, is a reasonable choice of the optimal value of the design angle of installation of nozzles in a radial-axial turbine, taking into account both its effective power and the coefficient of completeness of using the supplied pulse energy. The authors applied a closed-loop model of the combined engine, embedded in a new calculation method, which was divided into conditional blocks. In the first block, the method of indefinite Lagrange multipliers calculates the optimal values of the turbine elements in which the gas moves. In the second block, for a preliminary assessment of the calculated geometrical parameters of the flow path, the turbine characteristics are calculated: an assumption is made about the one-dimensionality and quasi-stationary flow. For calculations, a method for calculating the parameters of a stage at an average radius was used, supplemented by a semi-empirical method for calculating gas energy losses during the movement of the latter from the turbine inlet to the outlet section. In the third block, the efficiency of the turbine was estimated when working together with a piston engine by using a closed model for it. This made it possible to objectively evaluate such characteristics of the turbine as efficiency and power, which are functionally related to the pressure pulse in the exhaust tract, which will make it possible to predict the operational characteristics of the turbine operating in conjunction with the combined engine.

In the article is considered the problem of achieving the optimal duration of the working stroke of a diesel engine piston during the expansion process and obtaining the maximum efficiency coefficient (EC). For this purpose, a hypothesis was put forward about the pumping action of the piston on the flow of expanding gases during the power stroke of an diesel internal combustion engine (ICE) as the piston moves from upper dead point (UDP) to bottom dead point (BDP).At a certain moment of expansion, the rate of the flow of expanding gases turns out to be equal to the rate with which the same flow is slowed down by the moving piston.The equality of these rates leads to the formation of a flow break line and has a significant impact on the nature of the change in the polytropic exponent; the value of the exponent becomes equal to one: n = 1. This indicates that the optimum duration of the engine’s working stroke has been achieved and corresponds to the maximum power that can be removed during the diesel engine’s operating cycle. An experimental relation was obtained between the initial p₁ and final p₂ pressures in the cylinder during gas expansion with the gas flow rate and the rate of deceleration of this flow due to the pumping action of the piston. An equation for the continuity of gas flow has been compiled for the process of gas expansion in the cylinder of an ICE with closed gas exchange organs. Based on this equation, the numericalvalue of the acceleration of gravity in the cylinder of ICE is obtained: g_ф ≈ 8,7 м/с² < g, which confirms the pumping action of the piston. A theoretical (and graphical) dependence of the polytropic process exponent on the flow rate of expanding gases is obtained. The dependence allows to calculate the polytropic exponent and establish the gas relaxation period, indicating the achievement of the optimal duration of the piston stroke.

The topic of the study is to consider the possibility of using experimental planning methods to mathematically describe areas of performance in relation to marine electromechanical systems. A definition is given and a graphic illustration of the field of operability is provided. It is shown that information about the boundary of the field of operability allows solving the most important tasks of controlling the state of ship electromechanical systems of various functional purposes. Possible ways of solving the problem of constructing a field of efficiency and the difficulties of their practical implementation are given. The method of analytical description of the operability domain is considered, which assumes an independent approximation of each hypersurface that makes up the operability domain. It is shown that for such an approximation it is convenient to use polynomial dependencies, which can be obtained as a result of using experimental planning methods. The main advantages of this approach are considered, including the possibility of solving the problem in the case of a high dimension of the space of primary parameters, in the space of which the area of operability is built. It is noted that in order to obtain a unified analytical description of the field of operability, the properties of logical R-functions can be used, which make it possible to make the transition from logical functions to analytical dependencies. It is proved that polynomial dependencies have the properties of R-functions and can be used in such a transformation. The resulting analytical description of the health area is universal and does not depend on the configuration of the area itself. Unlike the known methods of analytical approximation of the field of operability, it is characterized by an exceptionally low methodological error and allows us to solve with high reliability the problem of parametric synthesis of marine electromechanical systems according to the criterion of the reserve of operability, as well as the tasks of evaluating and predicting their condition during operation. The considered example clearly demonstrated the sequence of solving the problem of analytical description of the field of operability and allowed us to conclude about the complex configuration of this area even for special cases and the simplest electromechanical systems.

A numerical algorithm for optimizing the technological processes of diesel generator sets operating on various grades of fuel, implemented by means of CVX-technologies, is considered. Traditional algorithms have generally proven to be positive, but can be problematic for optimization due to the large number of variables and the nonlinearity of the model. In addition, due to the huge computational load, they can “stall” or become damaged when used to search for non-standard designs, such as asymmetric D-optimal and large-dimensional spatial structures. It is noted that an alternative to them is calculations in the CVX format, which are widespread and available for solving convex optimization problems. However, their application for the control of technological processes of energy saving in autonomous electric power complexes in transport is still limited. Based on the tools of the CVX package in MATLAB, using their usefulness and flexibility in comparison with traditional optimization methods, this paper proposes technical solutions aimed at developing energy-saving technologies for energy complexes of autonomous systems in the context of digital transformation. The application of energy saving management methods is presented in this study on the example of fuel consumption management by a group of diesel generators with different consumption characteristics of primary engines, for which optimal modes have been obtained at various options of active power consumption by the network. An example of calculating optimal modes in parallel operation of five DGA with CVX program codes is given, confirming the correctness of the proposed solutions. It is shown that the use of CVX programs in MATLAB demonstrates their usefulness and flexibility in comparison with traditional algorithms in the statistics of searching for various types of optimal approximate constructions by convex criterion for nonlinear models.

The topic of the work is the study of the reasons for increasing the efficiency of the use of marine container transportation in the entire supply chain. It is noted that the increase in their efficiency is explained by the possibility of transporting various types of cargo, the speed of handling vehicles, as well as the compactness of storage and safety of cargo. The problem of increasing ship capacity on the terms of shipping companies, which currently exists and is being solved by container terminal operators, has been formulated, which allows minimizing the time of ships parking in the port for processing, which in turn can be achieved by increasing the capacity of ships. Attention is drawn to the fact that reducing costs by increasing the efficiency of lifting and transport equipment stimulates investments in automation systems for almost all terminal operations, and in particular in lifting and transport equipment systems. It is emphasized that the automation process of container terminals differs depending on the task at hand (a new project is being considered or work is being carried out to automate an existing terminal). The implementation of automation at existing terminals is a more difficult task due to the problems of compatibility with the types of activities performed and resistance to ongoing changes, which primarily involve systematic and repetitive technological processes that can be programmed. Attention is drawn to the fact that container terminals use the latest operating systems to control and optimize the movement of containers inside the warehouse area (in particular, they are used at terminals where gantry cranes on a pneumatic (RTG) and on a rail (RMG) are used), and it is also emphasized that when working with RTG technology gantry cranes on a pneumatic vehicle are equipped with sensors connected to satellite positioning systems, which are located on the terminal area and on wheeled carts and are brought to the place of cargo operation by signals from the control room, at the same time, the dock operator controls only when lowering or lifting the container. Such information systems are also used on terminals operating using RMG technology. It is noted that automation of berthing container cranes is currently under development, since the complexity of its implementation lies in the fact that during pitching the vessel has a roll and a deflector, therefore, when moving it, it is difficult to determine the exact location of the container and the alignment of the spreader horizon with the container horizon, as a result, the guidance process? It requires additional time, which leads to a decrease in work productivity.

The issues of forecasting the load of vehicles, route networks, formation of collection centers for cargo flows, including dangerous goods, in territorial planning systems determine the need for transition from deterministic models to dynamic models with the possibility of taking into account the influence of the external environment. Existing information transportation systems in the sphere of work with dangerous goods are based on deterministic models and allow to study the problems of forecasting changes to a limited extent. Models of routing networks construction on cargo vehicles are limitedly applicable when there is a task of dangerous goods transportation taking into account the presence of a distributed system of accumulation centers both in the city and, for example, within a large transport hub, seaport with different terminals. The paper presents routing models adapted to the conditions of dangerous goods transportation. Determining transport efficiency and the main costs of transport enterprises is the scheme of traffic flows, fixed in the territorial scheme. The task of the study is to develop a separate automation toolkit for decision making on the number and type of specialized transport (depending on the load capacity) to work with dangerous goods and large-sized objects within the existing flow scheme. On the basis of the research of the group of companies the conclusion is presented that today the task of choosing the optimal amount of transport by carriers is solved, as a rule, not systematically, but by operative construction of a set of routes, and does not involve primary analysis of the territory and parameters of accumulation sites. The presented study considers a new approach to the analysis of the system of transportation of hazardous waste, associated large cargoes, in terms of assessing the necessary list of universal structured input data, which are primary principled and characterize the complexity of work in the selected facility, terminal. To solve the problem of forecasting the load of vehicles is offered developed a new automation subprogram based on the organization of client-server access to data, and implemented in the internal programming language “1C. Management of motor transport” (version ММT 8.2). The presented automation subprogram provides data connectivity on volumes of dangerous goods cargo flows, cargo flow collection centers, available data on vehicles and planned data on removal schedules. Work of the subprogram provides integration of work with other databases of transport companies and allows to carry out modeling of various variants of placement of centers of collection of dangerous goods, centers of cargo flows with high accuracy. The obtained results allow to determine the required number of vehicles, their load taking into account different types and technical capabilities, as well as to determine the required number of vehicle trips in the serviced area taking into account the dynamic influence of the external environment. The presented methodology of working with data, performed in a separate automation subprogram, presented routing models, adapted to the transportation of dangerous goods, can be applied to various transport systems, including sea cargo ports and terminals, which determines the universality of the presented approach.

One of the ways to improve navigation safety during water transport operation is to develop automated devices and systems that reduce the number of tasks for workers. For example, the introduction of vessels with different levels of autonomy into production activities, capable of automatically monitoring the environment or delivering cargo, helps to reduce the size of the vessel due to the absence of a residential superstructure. On inland waterways, one of the limitations of the introduction of autonomous navigation is their safe passage through shipping passages — shipping locks. Mooring a vessel in a lock chamber is very labor-intensive and is usually performed by crew members of the vessel being locked for movable (floating hoops) or fixed (berthing bollards, bollards, hoops) mooring devices, the permissible loads of which are established in regulatory documents. Over the past 10 years, the authors have not found studies describing the results of measuring the loads on mooring devices and ropes arising from the movement of the vessel in the lock chamber. Another constraint to the implementation of autonomous shipping is the lack of requirements for auto-mooring devices that ensure the retention of vessels in the lock chamber. In this regard, the purpose of this study is to compare the standard and actual values of the load on mooring eyes and ropes for the theoretical calculation of the holding forces of the vacuum automooring device model, taking into account the operating conditions in the shipping lock chamber. The measurement results presented in the article were obtained in the course of the research work “Development of scientifically based recommendations for establishing hydraulic modes for filling and emptying the chambers of locks No. 1–8 of the Federal State Budgetary Institution “Volga-Balt Administration” based on in-kind studies of the conditions of ship mooring in lock chambers” commissioned by the Federal Agency for Maritime and River Transport using a strain gauge installed in the mooring rope cut. As a result of the theoretical calculation of the holding force of the vacuum auto-mooring device, the holding forces of the vacuum gripper from the radius of one vacuum suction cup were obtained.

The article presents the results of a study to determine the most rational method of automatic mooring of vessels in a navigation lock chamber. The relevance of the study is due to updated regulatory requirements in the field of designing the specified shipping hydraulic structures, the need to improve the efficiency and safety of navigation, including ensuring the passage of unmanned vessels, as well as the lack of ready-made technical solutions for their installation on the structures in question. To solve this problem, the authors of the study used the method of expert assessments, which allows taking into account the opinions and experience of specialists in the field of shipping, which ensures a more objective and reasonable choice of the most rational method of automatic mooring. As a method of expert assessment, taking into account the issues under consideration, the method of point assessments was chosen. For this purpose, during the study, a survey was conducted among the involved experts, during which each of them gave his intuitionistic assessment. In this study, vacuum, electromagnetic and lever-andhinge devices are considered as methods of automatic mooring. The criteria considered include, among other things, the need to reconstruct the lock chamber, environmental friendliness, the ability to hold the vessel, the complexity of the device, and reliability indicators. As a result of collecting and processing the obtained data, it was found that the most preferable method of auto-mooring of vessels in the lock chamber is a vacuum device. The results obtained indicate the feasibility of developing and implementing vacuum auto-mooring devices on shipping hydraulic structures. The results of the study are of practical interest to specialists in the field of shipping and can be used in the design and reconstruction of navigation locks.