The article develops an approach to designing an innovative means of reducing the wind-induced drift velocity of life rafts by using wave energy concentrated in the orbital motion of a raft on the wave profile. The relevance of the study is determined by the need to reduce the drift velocity of life-saving appliances, since this makes it possible to reduce the search area and increase the probability of rescuing people. The aim of the study is to develop a methodology for designing a hydrodynamic anchor in order to determine the parameters of the “raft–cable–hydrodynamic anchor” system that are sufficient to ensure a specified reduction in the drift velocity of a life-saving appliance under the worst conditions of the vessel’s navigation area. To achieve this aim, several interrelated tasks were solved in the course of the study, including obtaining and evaluating the results of studies of the hydrodynamic forces acting on the hydrodynamic anchor; analysing the effectiveness of the hydrodynamic anchor as a means of counteracting life raft drift; and developing methods for experimentally obtaining the operating parameters of the hydrodynamic anchor in relation to typical hydrometeorological drift conditions. The paper shows the relationship between the parameters of the “raft–cable–hydrodynamic anchor” system and presents a calculation of raft drift velocity for several wind speed values in the range from 6 to 20 m/s. For the purposes of designing a hydrodynamic anchor for specified drift conditions, the forces acting on the hydrodynamic anchor are presented in dimensionless form, taking into account the approximation of wave heights through wind speed according to the modern Beaufort scale. The proposed methodological model reflects an integrated approach to assessing the effectiveness of a hydrodynamic anchor in reducing raft drift. The use of a dimensionless coefficient and consideration of the true velocity of the hydrodynamic anchor through its projections demonstrated high efficiency in calculating cable tension in the life-saving appliance system. The proposed methodology reduces the required number of experiments. The results obtained make it possible to identify inconsistencies between related stages of hydrodynamic anchor operation and provide a scientific basis for improving the design of the hydrodynamic anchor and increasing its efficiency.

The article proposes a methodological approach and algorithmic tools for the simulation modelling of a transport and logistics system operating under the specified conditions. The method is based on the formalisation of a system of circular routes for ice-class vessels and linear icebreakers using a discrete vector representation, which transforms the cyclic structure into a linear one in order to simplify computational procedures. To automate the labour-intensive process of preparing initial data, a special algorithm has been developed which, based on a graphical representation of routes and the application of a wave algorithm, constructs their complete coordinate-by-coordinate description and forms the discrete working vector of the model. This makes it possible to minimise manual input errors and ensure the reproducibility of experiments. The model simulates the key technological processes: vessel movement along routes, queue formation at roadsteads at the points where icebreaker assistance begins, the formation of “icebreaker–vessel” pairs, and their joint movement along the ice-covered section. The target indicators used to analyse various scenarios include the total voyage cycle time, queue waiting time, icebreaker fleet utilisation, and the overall carrying capacity of the system. The practical significance of the study lies in the creation of a tool for multivariate analysis and synthesis of the parameters of the Arctic logistics chain. The model makes it possible to provide quantitative justification for decisions on the optimal composition and number of LNG carriers and icebreakers, to assess the influence of navigational conditions on the regularity of deliveries and, consequently, to improve the validity of strategic investment and operational management decisions for projects such as Arctic LNG 2. The developed approach contributes to the advancement of methods for planning sustainable and cost-effective transportation in the Arctic zone of the Russian Federation.

The paper examines various mental functional states, which can be divided into two broad categories depending on their impact on performance: favourable and unfavourable for professional activity. It is noted that all unfavourable functional states in seafarers are commonly referred to by the general term “ fatigue”, and that the probability of errors made by seafarers in an unfavourable functional state increases significantly. Fatigue manifests itself in the physical, cognitive, and behavioural domains of human activity. The study examines the transition from physical fatigue to other unfavourable functional states associated with changes in the cognitive and behavioural domains. It is noted that the monitoring and regulation of physical fatigue are primarily ensured by good-quality sleep. The role of sleep and its impact on human health and condition are analysed, in particular the reasons for the influence of sleep on human activity in relation to existing theories of sleep. The main provisions of modern theories of sleep are considered: energy conservation, information-processing, psychodynamic, glymphatic, and visceral theories, including sleep assessment criteria such as duration and structure. The main sleep parameters, including sleep efficiency, the number of sleep cycles, slow-wave sleep, and REM sleep, are analysed. The paper provides an overview of sleep assessment methods: polysomnography, actigraphy, and subjective sleep assessment. It is concluded that, under current shipboard conditions, the use of a subjective method implemented through a sleep diary is recommended. An improved form of a sleep diary is proposed, including the procedure for keeping it and analysing its content; conclusions are drawn and recommendations are provided on sleep quality and the regulation of physical fatigue.

The article presents the results of an analysis of cargo turnover in five sea basins of the Russian Federation for 2021–2024. The analysis of port and sea basin operations, carried out on the basis of available statistical data, makes it possible to identify trends in their future development, which depend on both coastal shipping and foreign economic relations. Forecasting cargo turnover using existing methods enables sea basins and individual ports to optimise cargo-handling operations, plan organisational and technical measures for the operation and maintenance of lifting and handling equipment, coordinate cargo flow directions, and determine the amount of cargo to be stored in warehouses. Managing these indicators makes it possible to plan the utilisation of warehouse areas at seaports, prepare vessel consignments in a timely manner, and avoid vessel downtime during cargo operations. The analysis and forecasting of various types of economic activity are carried out using expert assessment and various mathematical methods, which are probabilistic in nature. This study applies the Holt-Winters method, which provided the most accurate forecast based on the results of the analysis. Following the cargo turnover forecast for 2025 obtained using the Holt-Winters method, the predicted values were compared with the actual data. To verify the degree of agreement between the forecast and the actual values, an additional calculation was performed using a built-in Microsoft Excel function. The application of these forecasting methods makes it possible to analyse cargo turnover in sea basins in order to mitigate potential conflicts during cargo transshipment, support prompt decision-making, and ensure the rational use of port infrastructure within each sea basin. The comparison of the methods considered shows that the cargo turnover values obtained using these methods are close to the actual statistical data.

The paper studies the controllability of a vessel equipped with azimuth thrusters when operating in ice conditions. The relevance of the study is determined by the increasing intensity of navigation in Arctic and subarctic regions, where vessel movement is affected by ice cover, wind, and sea currents. Under such conditions, vessel manoeuvring characteristics are of particular importance for ensuring navigational safety and improving the operational efficiency of ice-class vessels. The paper considers the specific features of the operation of azimuth and bow thrusters during manoeuvring in ice. It is shown that the ability to rotate the azimuth thruster unit makes it possible to generate thrust in any direction in the horizontal plane, thereby ensuring high vessel manoeuvrability when performing complex manoeuvres and operating at low speeds. At the same time, it is noted that interaction between the propeller and ice reduces propulsion efficiency due to disruption of the flow structure, ice fragmentation, and additional vibration loads. A mathematical model of vessel motion in ice conditions is presented on the basis of differential equations that take into account the forces and moments generated by propulsion devices, wind action, sea current, and ice resistance. The model uses empirical and semi-empirical relationships to estimate aerodynamic, hydrodynamic, and ice loads. Particular attention is paid to ice resistance, including components associated with ice cover failure, the movement of ice fragments, and dynamic impact interaction between the vessel hull and ice. The obtained mathematical model makes it possible to comprehensively consider the main environmental factors and the characteristics of the propulsion system when analysing vessel manoeuvrability. The research results can be used in developing methods for calculating the controllability of ice-going vessels, as well as in improving dynamic positioning systems and vessel motion control systems under severe ice conditions.

The article presents an overview of the current state of the Russian shipbuilding industry, with a focus on the capabilities of domestic shipyards to build large-tonnage vessels. The study addresses the critical dependence of Russian shipbuilding and ship propulsion systems on imported marine engines, as well as the need to ensure national technological sovereignty in the maritime sector. The object of the study is the Russian shipbuilding industry, while the subject is the production capacity of leading enterprises and the feasibility of developing high-power low-speed marine engines. The aim of the study is to assess the industry’s readiness for large-tonnage shipbuilding and marine engine production. The research is based on the analysis of open sources and strategic documents, mathematical modelling of the required propulsion power in accordance with the recommendations of the International Maritime Organization (IMO), and comparison with the world’s leading marine engine manufacturers. The results show that the number of building berths suitable for Aframax-class commercial vessels is close to the limits set in strategic planning documents, while the physical capacity to build vessels with a displacement of more than 100,000 tonnes remains limited and requires shipyard modernization. The absence of domestic production of low-speed marine engines with a power output exceeding 7 MW creates a systemic gap caused not only by the impossibility of purchasing such engines, but also by the difficulties associated with international industrial cooperation. Import substitution of main engines requires not only production facilities, but also the revival of engineering research schools, including technological schools and schools specializing in the calculation of thermodynamic and dynamic loads. A separate challenge is the design of ice-strengthened vessels for year-round operation on the Northern Sea Route. Such vessels require power output of up to 45 MW, which cannot be provided by a single low-speed engine. At the same time, the installation of several such engines is a complex technical task that involves the design of the entire propulsion system and an integrated ship power plant.

The paper presents a comprehensive analysis of existing active and passive methods for water management in fuel cells. The study aims to experimentally evaluate the effect of directed gas-dynamic oscillations in the audible frequency range on the performance of a single fuel cell, as well as to develop recommendations for improving such systems for shipboard power plants. The configuration of the developed laboratory test bench for in situ testing under electrochemical reaction conditions is described using a prototype cell with an active area of 25 cm² and an external gas-dynamic generator. It was found that gas-dynamic excitation at the fundamental frequency of 1.68 kHz increases the power density of the studied cell by more than 25% due to the intensification of mass transfer processes and the efficient removal of excess moisture. The obtained results experimentally confirm the prospects for integrating gas-dynamic control systems into shipboard fuel cell power plants. A distinctive feature of this study compared with similar studies is the implementation of in situ tests using an external gas-dynamic generator operating in the audible frequency range. For the first time in the Russian scientific literature, the resonant mechanism of gas-dynamic action on gaseous reactants and the membrane electrode assembly is experimentally substantiated, and the possibility of a significant increase in fuel cell output power using the proposed method is demonstrated. The relevance of the study is determined by the need to decarbonize waterborne transport in accordance with the requirements of the International Maritime Organization, as well as by the absence of active gas-dynamic water management systems for shipboard fuel cell power plants in Russia. The results obtained can be used as a basis for developing adaptive moisture removal systems operating under actual operating conditions.

The paper analyzes the main operating characteristics of coaxial impellers of an active-type axial turbine stage operating in counter-rotation at different circumferential velocity ratios. The study was carried out to ensure the coordinated operation of counter-rotating impellers and the two auxiliary mechanisms driven by them, which makes it possible to reduce the total number of drive units. Optimal values of the outlet angles of the blade rows corresponding to the maximum efficiency of the turbine stage were obtained. It was found that an increase in the circumferential velocity of the second impeller relative to that of the first impeller leads to a decrease in the optimal outlet angles of the blade rows, with the most pronounced decrease observed for the second blade row. In the course of the study, the circumferential velocity ratio of the counter-rotating impellers was varied by changing the circumferential velocity of the second impeller. In this case, the external characteristics of the first impeller as functions of the speed characteristic remained unchanged, while the characteristics of the turbine stage varied due to the parameters of the second impeller. The effect of the circumferential velocity ratio on the optimal speed characteristic of the turbine stage and the second impeller was determined. The obtained power and torque performance indicators can serve as a basis for selecting auxiliary mechanisms driven by counter-rotating impellers in the design of ships and their power plants.

The paper analyzes the causes of the main failures of the cylinder-piston group of marine diesel engines, which in most cases occur due to the effect of high temperatures and pressures on engine components. The purpose of the study is to provide a computational assessment of the influence of in-cylinder operating parameters on the thermal-stress state of the cylinder liner of a small-size marine diesel engine 4Ch8.5/11 under rated operating conditions. The study was carried out using the finite element method implemented in the Ansys software package, which was applied to solve the problems of thermomechanical analysis of the cylinder liner. During the calculations, experimental data were used as boundary temperature conditions, while the indicator diagram obtained for this marine diesel engine was used to define the boundary pressure conditions acting on the cylinder liner. The thermomechanical analysis was performed with a gradual increase in the calculated loads. The study included two stages: at the first stage, the temperature field in the cylinder liner was determined taking into account the applied thermal loads and material properties, and the heat flow through the liner walls was calculated; at the second stage, the calculated temperature parameters were used to determine the liner deformations taking into account the pressures acting on it. The results showed that the maximum total deformation caused by thermal and mechanical loads is observed in the upper part of the cylinder liner. Safety factors were determined under actual loads corresponding to the rated power mode. The research results can be used for the design modernization of the components of the cylinder-piston group of the 4Ch8.5/11 diesel engine, as well as for determining the possibilities of its further power uprating.

The object of this study is systems for ensuring the environmental safety of marine internal combustion engines, in particular, technologies for limiting nitrogen oxides (NOx) emissions. The focus is on selective catalytic reduction (SCR) systems as the most tested and widely used technology for reducing NOx emissions in marine diesel exhaust gases, used in marine engineering to comply with the environmental safety requirements of the International Maritime Organization (IMO). The paper presents current requirements for reducing NOx emissions in different navigation areas. The main theoretical aspects of catalytic reactions for nitrogen oxides reduction and the organization of the conditions required for these reactions are analyzed. Special attention is paid to ensuring the temperature conditions required for SCR reactions; the operating limits are identified, and the causes of these limitations are determined. The article considers arrangement layouts, describes the operating features of high- and low-pressure SCR systems, and compares their advantages and disadvantages. It is noted that lowpressure systems are the most preferable for the modernization of marine power plants because they can be integrated as autonomous systems, despite their potential drawbacks related to maintaining the temperature conditions required for the reduction reaction. Attention is paid to auxiliary subsystems supporting the operation of selective catalytic reduction systems for nitrogen oxides, and their features are described. Some calculated data on the operating costs of the SCR system are provided, including additional engine fuel consumption, the reducing agents used, increased electrical power consumption by marine power plants, consumables, and other operating costs. Conclusions are drawn regarding the effectiveness of SCR technology in comparison with alternative technologies for meeting the requirements of the current regulatory framework for the environmental safety of marine power plants.

The article presents the development of the BS-STIRLING 5.0 software package designed for computational modelling of operating processes in Stirling engines. The new version, developed on the basis of the methodological framework of BS-STIRLING 4.2, includes a number of significant improvements aimed at increasing physical detail and calculation accuracy while maintaining the high computational efficiency typical of second-order methods. The key innovation is the transition from a functional diagram representation of the engine to discretisation of the internal circuit into 44 control volumes, which makes it possible to analyse local thermodynamic, hydrodynamic, and heat-transfer processes during the operating cycle. Additional improvements include a globally coupled iterative scheme, explicit modelling of heat transfer in the cylinders, updated correlations for oscillatory flows at low Reynolds numbers, a heat-transfer model taking into account wall temperature gradients, and the introduction of two new input parameters: adiabatic control temperatures in the hot and cold cylinders. These changes significantly improve the accuracy of calculating indicator diagrams, heat losses, and effective cycle parameters. Validation against experimental data from 29 Stirling engines of various types showed that the discrepancy between calculated and experimental values of effective power and efficiency does not exceed 5 %. Compared with version 4.2, the average error in power prediction was reduced from 5.2 % to 4.9 %, while the efficiency error decreased from 13.6 % to 4.1 %. The software package has a user-friendly graphical interface, short calculation time, and extensive visualisation capabilities, which makes BS-STIRLING 5.0 an effective tool for engineering calculations, scientific research, and educational purposes.

The paper studies and analyzes the formal definition and substantive interpretation of an information-based assessment of the design reliability of automated control systems for large water transport facilities with distributed locations, such as ports, shipping companies, and regional networks of regulated inland waterways. The concept of “project entropy” and the related measure of information uncertainty are introduced in connection with optimization mathematical models describing the interaction between reliability and cost indicators of automated control systems. The paper reviews and analyzes publications dealing with the transfer of the probabilistic-theoretical definition of entropy of a finite scheme of a complete system of events, proposed by Shannon and Khinchin, to models of the functioning of technical and techno-economic systems, as well as publications on the relationship between project entropy and Kolmogorov information in the context of optimization aspects of design. The concept of design entropy is formulated with regard to mathematical models for optimizing design reliability at the development stage. A method is described for constructing an entropy estimate for the preliminary design of an automated control system for a water transport production-and-economic system, with hardware, software, and data storage subsystems identified within it, as previously discussed in the first author’s publications. In this paper, entropy is treated as a measure of information lost when a project deviates from an optimal or quasi-optimal variant. The reliability factors used as arguments of the objective function include technical indicators, such as mean time between failures and restoration time, as well as economic indicators, including the initial cost of hardware and the cost of restoration, which are relevant under the limited overall budget of an automated control system throughout its life cycle. It is shown that the entropy of the optimal plan of an extremal problem on a discrete finite feasible domain is equal to the logarithm of the domain cardinality. The conclusion is drawn that the optimal plan is characterized by maximum uncertainty and the most complete use of the information represented by the feasible domain of constraints.

The purpose of the study is to monitor the technical condition of ships and water transport facilities during operation and repair, as well as to manage product quality under the digital transformation of production and services. For this purpose, an algorithm has been synthesized for automating the parametric identification of distribution laws for samples of measured time-to-failure data of components and instruments of ship systems using the Kolmogorov goodness-of-fit criterion, numerical methods of computer simulation and differentiation, and neural-network regression of the obtained probability density. The algorithm is applicable in automated control systems and softwareand- measurement complexes on ships and at water transport facilities when processing the results of observations, measurements, inspection, and product testing. In addition, the proposed algorithm can be used in cases where the processing of experimental data requires solving problems related to the analysis of the statistical properties of distributions that do not always fit within the theory of normal processes, for which parametric statistical tests, such as Student’s and Fisher’s tests, and nonparametric tests, such as the Kolmogorov, Cramér–von Mises–Smirnov, Anderson–Darling, Cooper, and other tests, have been developed. Unlike parametric tests, which are based on the assumption that the statistic follows a normal (Gaussian) distribution, nonparametric tests do not require the assumption of a known sample distribution law and are designed to compare an empirical distribution with a theoretical distribution, for example, a normal distribution, or with another empirical distribution. To implement these tests, null and alternative hypotheses are formulated; to verify them, probabilistic models of empirical and hypothetical distribution functions are constructed using analytical and numerical methods of statistical analysis, and the discrepancy between them is determined. Taking into account the high accuracy requirements that analytical methods cannot satisfy, an algorithm has been developed and implemented as a software program for identifying, by a confidence indicator, whether the tested distribution conforms to the normal distribution according to the Kolmogorov goodness-of-fit criterion, with estimation of its parameters, namely the mean and standard deviation, using a feedforward neural network with feedback connections, which provides fast training and acceptable accuracy. The results of computer and numerical simulation of the neural-network algorithm for parametric identification confirm the adequacy of the tested probabilistic model to the specified normal distribution.

This paper presents the development of an intelligent conversational assistant designed to support users in obtaining and clarifying information about university class schedules. The evolution of dialogue systems is considered, from early rule-based text dialogue programs based on pattern matching of input utterances to modern virtual assistants implemented using neural transformer architectures and large language models. The relevance of the study is determined by the use of large language models in combination with Retrieval-Augmented Generation (RAG), which makes it possible to generate responses based on information retrieved from external sources. An architecture of an intelligent conversational assistant has been developed that integrates a RAG mechanism, dynamic routing between several neural language models, and automatic updating of the knowledge base through parsing Admiral F. F. Ushakov State Maritime University web resources. The proposed approach ensures robust processing of variable user queries and response generation based on the retrieved context. Unlike existing solutions that rely on a fixed language model, the proposed architecture implements adaptive selection of a generative model depending on the type of user query. A method for domain-oriented context construction for processing dynamically updated tabular schedule data has been developed, including specialized web page parsing, semantic structuring of the extracted information, and prompt engineering rules. To improve the factual reliability of responses, a mechanism is proposed that constrains generation to the retrieved data and applies terminological filtering. An ETL pipeline for updating the knowledge base has been implemented, enabling automatic updating of information about university class schedules. A comparative study of the effectiveness of the Qwen, GigaChat, and DeepSeek language models in processing user queries within the considered subject domain has been conducted. The obtained results demonstrate improved response accuracy and confirm the effectiveness of the proposed conversational assistant architecture.