Herald of the Odessa National Maritime University

Analysis of hydrostatic characteristics and justification of the select superfull hull form of the subsea construction vessels

2025-10-05T20:14:58+00:00

Within the research the analysis of hydrostatic characteristics such as volumetric and weight displacement, buoyancy center abscissa, buoyancy center appliqué, waterline area, waterline area center of gravity abscissa, waterline area transverse moment of inertia, waterline area longitudinal moment of inertia, transverse metacentric radius, block coefficient, waterline area coefficient, midshipsection coefficient, and justification of the choice of a superfull hull form of the subsea construction vessel was made. At the same time, the system analysis and mathematical model of justification of the select of a superfull shell was developed considering influence on the main dimension of the vessel of load-lifting devices, a diving complex, a mobile drilling complex, a pipelaying complex, the cablelaying equipment and hydrostatic characteristics. The block diagram reflecting an algorithm of a research and justification of a superfull shell is made. The mathematical model describing researches of justification of a superfull shell of the subsea construction vessels is made. Dependences of hydrostatic characteristics of the studied shell of the subsea construction vessel were developed for justification of the select of a shell of a superfull form and comparison with a superfull shell is executed. At the same time, a systematic analysis and mathematical model were developed to justify the choice of ansuperfull hull form, taking into account the impact on the main dimensions of the vessel of lifting devices, diving complex, mobile drilling complex, pipe- laying complex, cable-laying equipment, and hydrostatic characteristics. A structural diagram was drawn up reflecting the algorithm for researching and justifying the super- full hull form. A mathematical model was developed describing the research to justify the superfull hull form of a vessel for underwater construction work. The dependencies of the hydrostatic characteristics of the vessel's hull were developed to justify the contours of the superfull hull form. Analysis of the hydrostatic characteristics of the studied superfull hulls allowed us to make an informed choice of hull shape for a vessel for underwater construction work. A calculation method was developed, the main characteristics were determined, and preliminary estimates of the required power of the main engines of a vessel with a superfull hull for underwater construction work were made. To confirm the reliability of the calculation model, a comparative diagram of calculations was developed using the CFD model of an existing vessel with an overfilled hull shape that is in operation, and a calculation of the superfull hull shape of a vessel for underwater construction work. As a result of the study, the superfull hull shape of the vessel for underwater construction work was confirmed.

Assessment of loads for floating cranes «STRIZH» and «PK-888» in contact with the side of a «PANAMAX» bulk carrier

2025-10-05T20:15:04+00:00

In this article, various options for calculating the loads on the sides of floating cranes that arise as a result of contact with the vessel during cargo operations are considered. A scheme of complex mechanization of bulk cargo handling using two floating cranes is proposed. A bulk carrier of the PANAMAX type is taken as the «standard vessel», in the most dangerous condition from the point of view of loads from the action of the wind, namely: the «empty vessel» option. With such a variant, the vessel has the largest sailing area and, as a result, the largest value of the force from the action of the wind acting on the hulls of floating cranes. Various schemes for calculating wind loads are used, which are set out in the rules of the Register of Shipping of Ukraine, hydrotechnical literature and building codes. When assessing the strength of the hulls of floating cranes, data on measurements of the residual thicknesses of the hull structures of these floating structures were used.

Composite materials in shipbuilding: prospects and challenges

2025-10-05T20:15:09+00:00

This article presents a systematic analysis of the potential of composite materials in modern shipbuilding, particularly from the perspective of their functional purpose, durability, technological compatibility, and environmental suitability. The aim of the work is to achieve a scientifically sound classification of composite materials suitable for use in shipbuilding, as well as to identify promising areas for their application and limitations in marine environments. The research process employs a review and analytical approach, including methods of typologization, comparative analysis of the physical and mechanical characteristics of materials, critical evaluation of literature sources, and current regulatory documents. The source base comprises over 30 scientific publications. A functional classification of composite materials is formed based on the characteristics of chemical nature, type of reinforcement, source of origin, and field of application. Five promising types of composites are highlighted: fiber-reinforced polymers (FRP), syntactic foams, hybrid composites, inorganic fire-resistant systems, and environmentally oriented biocomposites. For each of these, a description of properties, typical areas of application, technological advantages, and operational limitations are provided. The scientific novelty of the research lies in the interdisciplinary approach to the evaluation of composites in the context of the marine environment - considering not only structural and economic but also environmental and regulatory factors. Prospects for the further integration of composites into critical elements of ship systems, along with the development of recycling and repair technologies, are outlined. The practical significance of the results lies in the possibility of their use for decision-making at the stages of material selection, design, standardization, and fleet renewal. The presented conclusions can be taken into account in the development of national and industry recommendations for the implementation of composite materials in marine engineering.

Investigation of dynamic loads in the lifting mechanism of gantry cranes «SOKIL »

2025-10-05T20:15:14+00:00

In this paper, we study the dynamic loads acting on the ropes of the SOKIL portal crane lifting drive during the overload of forest logs according to the «warehouse-ship» scheme in a river port. An electrotensometric method was used to analyze the nature of changes in dynamic forces in the drive elements. The analysis shows that the dynamic loads in the lifting drive of portal grab cranes, which have been in operation for more than four decades, are insufficiently studied. It should be emphasized that each crane requires an individual approach to research, since the dynamic parameters of its mechanisms are significantly affected by operating conditions, geometric characteristics, as well as physical and mechanical properties. The results obtained indicate that when loading loads weighing from 11 to 15 tons, the dynamic force coefficients in traction ropes range from 1.18 to 2.45. the dependence of these coefficients on the weight of the load is nonlinear..

Correction of the methodology for calculating rope drums of cargo lifting machines

2025-10-05T20:15:17+00:00

Analysis of the traditional calculation method for rope drums of lifting machines shows that it takes into account only part of the stresses that arise in the walls during loading operations.In this work determines the spectrum of stresses to which the drum wall is subjected as a thin shell, loaded with a tensioned cargo rope. Methods for calculating the components of this spectrum are proposed and formulas for their determination are presented. This method for calculating of rope drums of lifting machines takes into account the influence of the ridges of the grooves, which designed to evenly lay the rope on the drum. The results of calculations are presented, which confirm the great influence on the stress state of the rope drum shell of components of the stress spectrum that are not taken into account by traditional methods.

Influence of thrusters’ electric motors power on the maneuvering properties of electric ships

2025-10-05T20:15:22+00:00

The aim of the study is to develop a method for assessing the impact of the thrusters’ electric motors power on electric ships’ maneuvering characteristics. The power of the thrusters’ electric motors on electric ships is comparable with the power of propulsion electric motors. In maneuvering modes, all components of the ship's electric power system constantly operate in transient modes. Analysis of the impact of the thrusters’ electric motors power on the electric ships’ maneuvering properties should be carried out taking into account the joint operation of all components of a single propulsion ship complex. The assessment method is based on a mathematical model of transient modes of propulsion systems. The calculation of the hydrodynamic characteristics of thrusters’ propellers is based on an analytical method that allows taking into account the processes of their interaction with the ship's hull in unspecified modes. The method for calculating transient modes makes it possible to assess the main indicators of maneuvering quality with simultaneous monitoring of additional loads on all components of the single ship's electric power system. The results of the study show that with an increase in the power of the thrusters’ electric motors, the maneuverability of ships improves. The electric power system is not overloaded. The degree of influence of the electric motors power on the maneuverability indicators of propulsion systems depends on the speed of the vessel's exit to a curved trajectory. Regularities in the influence of the power of the thrusters’ electric motors on the maneuverability indicators of electric ships are found. Proposals are formulated for a justified choice of the power of thrusters and forecasting the maneuverability of ships taking into account the capabilities of the electric power plant to ensure them. Bibl. 14, Table 1, Fig. 7.

Methods for search of optimal solutions when designing electric vessels’ propulsion power plants

2025-10-07T08:05:52+00:00

The aim of the study is to develop a method for parametric optimization of propulsion power plants of ships with electric propulsion. The optimization strategy is based on a systems approach. It is proposed to carry out comprehensive comparative assessments of the quality of the design of electric power plants primarily based on the criteria of the vessel as the senior system, for the operation of which the propulsion plant is intended. Target functions have been formed. A method for finding the optimal solution for multicriteria parametric optimization has been developed. Optimization calculations have been carried out. Optimal parameters of the propulsion electric power plant have been found that provide the best comprehensive indicators of maneuvering quality with different weighting factors between the optimality criteria. A quantitative assessment of the optimization efficiency has been carried out. A significant improvement in the main performance indicators of ships with an optimized electric power plant is illustrated compared to the original version. Scientific novelty and practical significance. A new method of multicriteria parametric optimization is proposed, which is effective for the optimal design of electric ships’ propulsion power plants . The efficiency of the develo- ped optimal design method has been proved.

Algorithms for automated investigation of modular-structure dc converters

2025-10-05T20:15:35+00:00

The article examines methodologies and algorithms for the automated study of modular-structure DC-DC converters (DCC) that combine single-phase and multi-phase conversion principles. An informational model of a software suite is proposed, enabling the investi- gation of time-domain and energy parameters of DCC and the assessment of their efficiency and quality indicators of electrical processes. Special attention is paid to the development of specialized software that implements the proposed generalized mathematical model and provides flexible parameter configuration (accumulation and transformation coefficients, etc.). The advantages of separating the calculation tasks into individual subprograms covering basic parameters, time-domain dependencies, quality indicators, and energy characteristics are substantiated. The proposed algorithms and software modules expand the computational capabilities of automated design systems while improving the accuracy and reliability of analyzing DCC with various types of power channels (buck, boost, and inverting).

Main ecological problems in sea transport. General characterization of environmental problems

2025-10-05T20:15:41+00:00

The maritime shipping industry, as a crucial component of the global economic system, is actively involved in solving the major global problems of our time, as more than 80 % of international trade is carried out by sea. Growth in the number of ships requires enhanced measures to improve environmental performance and safety of navigation Throughout the history of navigation, ships have been discharging everything that was considered unnecessary into the ocean: food waste, cargo residues, garbage, polluted water, etc. It was believed that the endless and deep sea would not be harmed by this. However, the possibilities of ocean self-cleaning are not unlimited, while the scale of marine activities is constantly growing. In this article, the authors review and systematize the analytical assessments of domestic and international experts on the problem of pollution and climate change, which requires immediate measures to reduce the negative impact of maritime transport on the environment. The purpose of the article is to outline the issues of main environmental problems in maritime transport and to summarize the results of published scientific research. We emphasize that environmental safety issues include the systematization of the constituent factors of marine pollution by oil, chemicals and other toxic substances, greenhouse gas emissions, loss of fuel tanks during accidents, etc. In our opinion, the identification and classification of the main causes of the impact of negative factors of maritime transport operation on the ecology and the state of the environment with a view to further reducing or eliminating this impact is an important topical problem of our time. To achieve the purpose of the study, theoretical methods of systematization, formalization, statistical processing and generalization of environmental monitoring data of domestic and world scientists were used. It is noted that scientific research in this area is considered to be the most promising.

Underwater LiDAR as a key component of integrated ocean research systems

2025-10-05T20:15:47+00:00

Light Detection and Ranging (LiDAR) technology is opening up new horizons for exploring the deep sea. While ground-based and airborne LiDAR systems are actively used to create high-precision topographic maps, underwater LiDAR systems represent an innovative and promising direction for bathymetric mapping. The proposed underwater LiDAR systems are capable of providing centimeter accuracy in coastal and shallow water areas where traditional acoustic methods face limitations. By using laser radiation in the blue-green spectral range (typically 532 nm), underwater LiDAR is able to penetrate the water column to depths of tens of meters, providing dense coverage of data points. The system can be integrated with autonomous underwater vehicles (AUVs), remotely operated vehicles (ROVs), or surface platforms to efficiently collect data on seabed topography, underwater object structure, and water environment characteristics. The development of affordable underwater LiDAR systems is of strategic importance for the development of science in the marine field, providing an opportunity to study in detail underwater landscapes, marine ecosystems, archaeological sites and coastal infrastructure. The implementation of this technology will contribute to the ambitious goal of complete mapping of the ocean floor by 2030, especially in areas where existing technologies are inefficient or inapplicable.

The methodological principles of adaptive managment of loading and anloading of ships

2025-10-05T20:15:54+00:00

The study was carried out with the aim of creating methodological support adaptive control of the process of loading and unloading of ships. This process is interpreted as a complex dynamic system with a reliable structure over short time intervals. It is shown that the achievement of this goal should be carried out on the basis of the smart port concept by intellectualizing adaptation as tools for implementing smart control by the mentioned process. It is noted that the advanced orientation remains poorly understood and requires in-depth research taking into account modern scientific trends in the field of management of production systems and processes. In accordance with this conclusion, an approach to the creation of a mechanism for managing the processing of vessels at a certain time with analysis of the logic of structuring, parameterization and division on stages steps. A two-loop adaptive control model was created by potential of software (planning), tracking (monitoring) and stabilizing (control regulation) in sliding (mobile) mode. A theoretical and methodological arsenal of adaptive control of the processing of loading and unloading of ships in the form of adaptive optimization algorithms for continuous maintenance of situational and calendar plans for loading and unloading of ships. The first of these algorithms is to manage a certain set of vessels that are accepted for service by the port over a set period of time. The second algorithm is intend a for drawing up adjustments and re-drawing up calendar plans for servicing locally considered vessels. Correct methods for solving local problems of ship maintenance management are proposed, which are distinguished by their simplicity, practical expediency in implementation.

Analysis of the activities of the operating ports of Ukraine under martial law

2025-10-05T20:16:01+00:00

The article presents an analysis of the operational activities of Ukrainian working ports under martial law. It outlines the current structural basis of Ukraine's maritime industry and highlights key concepts related to the state of seaports, categorizing them as: operational, non-functional due to proximity to military actions, or closed (temporarily occupied). An analysis of direct damage to the state-owned maritime and inland waterway transport infrastructure caused as a result of Russian aggression was conducted. The dynamics of cargo turnover changes from 2021 to 2024 in the seaports of the Danube region and «Great Odesa» are investigated and illustrated. The article also highlights hydrotechnical projects (fairway and water area deepening, berth infrastructure restoration) that improved navigation safety in the Danube and «Great Odesa» areas. Finally, it conducts a comparative analysis of port performance indicators under the Grain Corridor initiative and after its suspension.

System-theoretical assessment of the sustainability of maritime transport systems in the context of sustainable development

2025-10-05T20:16:06+00:00

The article conducts a theoretical and systematic assessment of the stability of Ukraine's maritime transport systems in the context of sustainable develop- ment. The content of ecological, economic and social components of sustainability is revealed, international approaches to its measurement are analyzed. Based on the Triple Bottom Line concept, an adapted system of indicators was proposed and an «input-process-output-impact» system model was built, which takes into account the peculiarities of the functioning of Ukrainian maritime logistics. The expediency of using this model for further quantitative assessment of the level of stability, strategic planning and integration into global logistics networks is substantiated. Emphasis is placed on the need to create a national monitoring system and an indicator base for the sustainability of the industry.

Mathematical model of optimal scenario selection of ship operations based on a risk-oriented network criterion

2025-10-05T20:16:09+00:00

The article develops a formalized model for choosing the optimal scenario for performing ship operations, taking into account the risk-oriented structure of the criteria. The methodology involves constructing a network relationship between performance criteria and risk factors that impact shipping safety. The possibility of aggregation of integral risk using the weight matrix and the function of adjusted utility with the risk-aversion parameter is considered. The model was tested on the example of a navigation transition with route alternatives, taking into account changes in weather conditions and the level of operational reliability. A scenario analysis was carried out using sensitivity methods, which made it possible to identify the influence of key factors on decision-making. The proposed approach can be integrated into the decision support system (DSS) of industry enterprises to increase the level of validity and adaptability of management decisions in conditions of uncertainty and risk. In particular, this method allows you to evaluate potential scenarios of further actions based on accumulated experience, and automatically form strategic priorities taking into account changes in the external environment. In addition, to quickly adapt operational processes, which is especially relevant for shipping companies operating in conditions of limited resources, regulatory pressure, and growing requirements for the safety and sustainability of enterprises.