This paper considers the state models of the system of autonomous guiding and mooring of ships and its key component — tugboat-automate. The
research aims at analyzing the functioning of the system of autonomous ship navigation and mooring, determining possible modes of operation and
conditions of transitions between states, as well as identifying factors affecting the efficiency of operations in the port water area. To formalize the
logic of operation of the system and its components, state graphs describing possible states, transitions between them and external influences are
used. Special attention is paid to the integration of autonomous tugboats, autonomous mooring systems and other automated solutions within a
single system. The developed models serve as a tool for deep understanding of the internal processes of the system, as well as identify bottlenecks
and potential risks, which creates a basis for further improvement of autonomous ship navigation technologies. The results of the work correspond
to the current international trends and the national strategy of the Russian Federation in the field of maritime industry modernization.

The paper examines the IMO regulatory framework for the assessment of GHG intensity over the life cycle for various types of marine fuels, including biofuels, in order to reduce the operational carbon intensity indicator of a ship. The purpose of the study is to analyze the provisions of these documents, mainly the 2024 Guidelines on Life Cycle GHG Intensity of Marine Fuels (2024 LCA Guidelines), existing and upcoming MARPOL requirements and other related documents which will determine the main directions of development not only of international shipping, but also of shipbuilding science and technology in the coming years and decades. The objective of the study was to determine the basic principles of accounting for greenhouse gas emissions from marine fuels, to identify criteria for the sustainability of marine fuels, to set procedures for GHG life cycle assessment of marine fuels as part of implementation of the relevant MARPOL requirements.

In the context of changing arctic oil supply routes due to geopolitical factors, the importance of developing the Northern Sea Route as a year-round transportation artery has significantly increased. The aim of the study is to assess the impact of ice class and operational conditions of vessels on the economic performance of oil transportation via the Northern Sea Route. The research methods are based on mathematical modeling of the annual operation of tankers. The novelty of the study lies in the consideration of ice condition scenarios, as well as in the comparative analysis of transportation with and without transshipment. This article presents a model for the annual operation of ice-class tankers transporting oil to Asia, considering ice and navigational conditions, route characteristics, and vessel speed parameters. Based on the model, operating costs for oil transportation via the Northern Sea Route using tankers of all arctic ice classes, as well as conventional vessels via the Southern Sea Route, have been calculated. Capital costs for the construction of tankers, total installed power, and power consumption under various operating conditions have also been determined. All calculated values are derived from realistic input data, taking into account prospective changes in shipping. A comparative analysis of the calculation results showed that transportation with transshipment is generally more efficient for high ice-class vessels, increasing the number of cargo deliveries by Arc7 — Arc9 ice-class vessels by an average of 40 % under optimistic and baseline ice condition scenarios, and by 20 — 30 % under the pessimistic scenario. The obtained results can support decision-making on fleet replenishment and the selection of optimal oil transportation schemes under changing ice conditions in the Arctic.

The article considers the features of wave formation during movement at speeds from 7 m/s to 11.7 m/s of bodies of various shapes: a sphere, an ellipsoid, a modified Wigley hull and a longitudinal cylinder with fairings with L/B = 1, 2, 4, 6, 8, 16 and a range of draft from 0,465 m to 0,865 m. The results of numerical modeling using the NUMECA/FineMarineTM software package are presented. The dependences of the coefficients of total resistance and heights of generated waves on the Froude numbers are presented. The influence of the main dimensions and shape of bodies on the coefficient of total resistance and generated wave heights is shown, as well as the nonlinearity of the wave formation process when changing the dimensions of bodies and drafts. The results obtained will be used for research in the field of reducing the wave resistance of a heavy-duty catamaran due to the interference of wave systems created by its hulls and an additional body installed in the interhull space, forming a general hydrodynamic complex with the vessel.

The operation of the vessel involves managing the influence of various external forces, including sea waves, that lead to ship motions. The safety of such operation is ensured by meeting special requirements or requirements of classification societies. At the same time, their full implementation does not guarantee acceptable living conditions for crew members or passengers on board in view of motions. For this purpose, in the second half of the 20th century, studies were initiated aimed at determining the limit values of certain parameters of ship motions, exceeding which reduces the efficiency of the crew, including those leading to motion sickness. The results of the research made it possible to develop a set of so-called seakeeping criteria to be included in relevant specialized standards. NORDFORSK, NATO STANAG 4154 and USCGC are the most widely used. Despite the significant human influence on the efficiency of ship operation, the application of seakeeping criteria in the design of ships in Russian practice is very limited. This article provides a brief overview of the formation of seakeeping criteria and relevant standards, as well as the results of applying some of them to the vessels, designed by JSC CMDB Almaz.

The ability to transport a wide range of cargoes makes container ships one of the most promising types of vessels in the modern merchant marine fleet. At the same time, not only their number is steadily increasing, but also the container capacity of the largest representatives of this type. The purpose of this study is to analyze the main characteristics of container ships and obtain functional dependencies for them, the application of which will allow determining the values of the main dimensions at the initial design stage. To find the desired expressions, it is proposed to refer to the available statistics reflecting the main characteristics of commissioned container ships and to conduct a detailed analysis of the available data. Of particular interest is the study of the dependencies of the characteristics of container ships of a certain deadweight group, which makes it possible to provide more accurate calculation functions for a specific technical specification. The relevance, comprehensiveness and complexity of the issue under study determine.

In December 2022, a new revision of International Association of Classification Societies Recommendation 34 came into force. The Recommendation includes completely updated data on wave statistics in the North Atlantic. The new revision of the document, on the one hand, made it possible to take into account modern methods of forecasting sea waves and the peculiarities of ship traffic on the North Atlantic routes; and on the other hand, it raised concerns among a number of international professional associations. A number of publications show that the calculated long-term wave parameters in the new revision have decreased compared to the previous revision of the Recommendation. In this article, independent comparative calculations of the long-term distribution of wave bending moment and wave shear force for four ships of different sizes and architectural and structural types are performed. The comparison between the values of wave loads using wave data in the previous revision of the Recommendation and the new revision are obtained. It is shown that the decrease in wave load values can reach up to 20 %. Additionally, the calculations of wave loads for the considered vessels were carried out in accordance with the requirements of regulatory documents. It was shown that despite the reduction in the wave loads obtained using direct calculation methods, good agreement of wave loads with the requirements of regulatory documents is ensured when using the new revision of the Recommendation.

The article examines the features of the methodology for conducting experiments on physical modeling of the process of long tsunami-type waves impact on a floating object and analyzes their results. It is assumed that when transporting liquefied natural gas to Asian countries, such storage facilities will be located in the bays of the Pacific Ocean. The specified transport corridor may be exposed to tsunami waves. Solving problems related to ensuring the safe operation of offshore facilities under the action of various types of external loads at their location is highly relevant and has practical significance. The paper examines the features of modeling the tsunami wave impact on hydraulic structures and presents a detailed description of the experimental setup with an analysis of its features. The main attention is paid to the methodology of conducting experimental works using sensors and an information system for measuring various quantities. Analysis of the experimental results indicates not only the need to measure the forces in the connections of the anchor system, but also the necessity of determining the movements of the floating object when it is exposed to a tsunami wave. Conclusions are drawn about the prospects of using ultrasonic sensors, as well as the need to consider the reflection of waves from the basin walls and take measures to eliminate or reduce the effects of waves reflected from the walls on the object under study.

The results of instrumented drop-weight tear tests of shipbuilding and pipeline steels with measurement of fracture (absorbed) energy are considered. Ratios are proposed for an assessment of the maximum fracture energy and its changes in presence of separations or cleavage areas in fracture. Introduction of the fracture energy measurement allows to avoid subjectivity of estimates of steels cold resistance based on fracture appearance visual analysis and to obtain data for comparison of pipeline steels in respect of both tendency to brittle fracture and ductile fracture energy.

The paper presents an analysis of existing types of vessels for the construction and maintenance of offshore wind farms. The characteristics of modern ships for the installation of wind turbines, cable ships, as well as ships for the construction and maintenance of wind turbines are presented. In the foreign literature on offshore wind energy, сommissioning service operation vessels (CSOV) and service operation vessels (SOV) are constantly mentioned as two different types of vessels. Correspondingly, this article aims to establish functional differences between these two types of vessels, to identify their main features and purpose. In addition, the article discusses devices for moving maintenance personnel between ships and wind turbines.

This article describes the evolution of the theory and practice of early ship design over the past 50 years, and analyzes the main Russian and foreign sources. The features of the analytical-, optimization- and system-based approaches to the formulation and solution of the design problem are consistently discussed, and the applied tools used in different approaches are described. A comparative analysis of these three approaches is carried out. Several assumptions are made about the ways for further development of the theory and practice of ship design using artificial intelligence and digital duplication technologies. The article also analyzes the reasons for some inertia of the ship design theory in modern Russia and a certain pause in the development of applied tools for conceptual ship design and analysis. A conclusion is made about the possibility for further development of ship design theory using modern information and software technologies.

The purpose of this article is to determine some prospective areas for the development and improvement of the steam distribution system and the electrohydraulic power control system for steam valves of the turbine unit of the main steam turbine unit PTU-72, installed on icebreakers of project 22220, and which is the base for use on prospective icebreaking vessels and floating nuclear power plants. The article considers the design features of steam valves and of the drive part of the turbine control system, which, according to the authors, require further development as part of the modernization of nuclear icebreaker power plants during their operation, and also require consideration when developing new advanced marine power units. Possible ways to improve the steam distribution system are considered in two areas: the design of control steam valves themselves and the design of electrohydraulic power complex for controlling steam valves.

The following suggestions are formulated for consideration in the design of new steam turbine units for nuclear-powered vessels:

1) to consider the issue of eliminating unjustified duplication of steam valves on the main turbine unit (MTU) of prospective projects and returning to the proven scheme of steam supply on turbines of nuclear icebreakers of the previous generation;

2) to consider the use of non-metallic composite materials in the design of prospective turbomachinery steam distribution systems;

3) to unify the steam control and etching valves with the exclusion of the relief valve from the etching valve, replacing it with an unloading channel, and structurally ensuring the process of self-mounting the piston on the rod inside the perforated sleeve;

4) in prospective icebreaker projects, to consider the possibility of reducing the pressure of the working medium in the hydraulic control system of the MTU steam valves, which will obviously reduce the requirements for hydraulic control elements and allow for simpler technical solutions with the transition to domestic hydraulic control systems, and possibly to the electromechanical design of steam valve control servos;

5) to change the control algorithm for control valves of turbine units of serial nuclear icebreakers of the project 22220, supplementing the algorithm with functionality that ensures an increase in the service life of steam valves by modernizing the electronic digital part of the steam turbine control system.

The proposed suggestions on improving the steam distribution system for serial nuclear icebreakers may be considerably useful in newly designed nuclear icebreaker power plants of the 10510 Leader project, as well as in turbine-generating plants of the actively developing field of nuclear floating power units.

The use of unloaded steam valves in steam distribution systems of turbogenerator installations of nuclear floating power units may pave the way for the use of electromechanical power drives of steam valves in turbine units with the exclusion of hydraulic high-pressure media from the drives.

The article analyzes the consumption of various types of marine fuel on Russian ships in 2019 — 2024 according to data from Russian shipowners submitted to IMO. The data obtained are compared with figures on the consumption of various types of fuel taken from IMO reports on the consumption of the global fleet. Data on the use of alternative fuels on marine vessels with a gross tonnage of 5,000 and more are presented. The comparison of the operational energy efficiency index CII (Carbon Intensity Indicator) of Russian ships and ships of the world fleet is carried out. Conclusions are drawn about a minor increase in LNG consumption, for which further growth requires the development of bunkering infrastructure in ports. The purpose of this article is to compare the energy efficiency indicators of Russian vessels with the energy efficiency indicators of the global fleet.

The aim of this paper is to analyze the requirements of foreign classification societies for 2023–2024 to stainless steel castings intended for use in shipbuilding. The rules of six foreign organizations (Indian register of shipping, China classification society, Bureau Veritas, American bureau of shipping, Det Norske Veritas, Registro Italiano navale) developing and applying technical standards in the field of design, construction and supervision of offshore facilities were studied. The mechanical properties of modern cast iron-based alloys, their chemical compositions, possible defects and requirements for corrosion tests were presented. Information and recommendations were given for the production of stainlesssteel castings widely used in shipbuilding and developed recently. The paper gives valuable information that helps to make reasonable requirements to the organization of shipbuilding production and to select shipbuilding materials with specified properties that ensure the required service life. Compliance with the requirements contributes to safety of navigation, protection of human life and environment.

On the basis of the research, requirements to castings from corrosion-resistant iron-based alloys and suggestions for implementation in the regulatory documents of the Maritime Register of Shipping (RS) were developed.