A unified algorithm for calculating the amount of loaded cargo is provided in the paper. The algorithm checks the vessel readiness to carry out survey work, on the basis of which further operations or the elimination of inconsistencies that have arisen, are proposed. Attention is paid in detail to the measurements carried out during the draft survey, necessary for calculating the average draft of the vessel. The error value is given as a percentage of the deadweight of the vessel, depending on the measured source. The necessary conditions for the issuance of a permit by a surveyor to carry out loading and unloading operations on a ship after checking the conformity of the results obtained with the declared data are defined in the paper. The “Bow-and-stern Sediment diagram” is investigated as a method intended for approximate, but at the same time fast, non-commercial calculation. It is proved that the calculation of the vessel displacement based on this diagram leads to a significant error resulting from a fundamental misunderstanding of the draft survey process and its purpose. The most common mistakes at using ship’s documents, as well as the formulas use, are discussed in the paper. The ways of reducing inaccuracies in calculations are determined. It’s substantiated in the paper that the use of the “average draft” and “river” formulas cannot be carried out for all types of vessels due to their possible specific design features, in particular, additional grades of deepening and the presence of hull bending. The specifics of the ship’s register documents are given. The values of errors are also analyzed if there are only register documents on the ship. It’s proved in the paper that the proposed unified algorithm for calculating the amount of loaded cargo is quite accurate compared to other methods considered. 

The ways of implementing international regulations in force since 2017 are considered in the paper. The main one is the receipt by the vessel of a Certificate of a polar navigation vessel, which is impossible without the availability of special documentation — Instructions for the operation of vessels in polar waters. The current international acts contain instructions for the development of such Manuals with detailed requirements for each section. Thus, according to the instructions in chapter 3 of the Instructions on interaction with Rescue and Search services, it is recommended to provide procedures for preparing for the voyage and for actions in emergency situations. The approaches for the development of recommendations for the safety of various types of vessels navigating in polar waters, including the analysis of various coupling options that can be implemented in polar navigation conditions, are elaborated in the paper. The various coupling options: in an ice caravan, in shallow ice, the creation of a rigid coupling (an option in which all possible mooring devices are brought between vessels), are proposed. The results of the study can significantly improve the safety of navigation in ice conditions, and can also form the basis for the development of operating instructions in polar waters and be adapted for practical use for various types of vessels. 

The paper concerns the study related to improving of level of safety at sea and reducing risk of marine accidents through development of conventions, codes and resolutions by the International Maritime Organization (IMO). IMO strives for each of the 175 Member States to properly implement and ensure enforcement of IMO instruments related to maritime safety. To assist Member States in implementing its instruments, IMO has been developing a special set of measures, which is currently enshrined within the IMO Member State Audit Scheme (IMSAS). IMSAS implies conduct of periodic audits in each IMO Member State, to assess how the audit standard, namely, the mandatory Code for the IMO Instruments Implementation (III Code) and IMO instruments (conventions, codes, etc.), to which the State is a party, are applied to the required extent and with the appropriate level of quality. In 2022, IMO adopted a number of decisions and documents, according to which further steps for the development of the Scheme, such as development of an recommendatory “Guidance in relation to IMO Member State Audit Scheme (IMSAS) to assist in the implementation of the III Code” (hereinafter referred to as Guidance) are planned. The purpose of the Guidance is to provide Member States with guidelines and recommendations in the implementation of the III Code and IMO instruments by clarifying and interpreting the relevant terms. The Guidance is currently in the final stage of development within the IMO Subcommittee on Implementation of IMO Instruments (III), and it is planned that the IMO Assembly will adopt it in 2023 with a recommendation status. In this paper, the Guidance is considered, its background and prerequisites for its development are investigated, its structure, composition, purpose are considered, as well as an assessment of quality and degree of its usefulness from the point of view of achieving the goals set during its development is given. The chapter of the Guidance listing typical findings issued during Member States audits is reviewed in detail, the most effective measures for their elimination are reviewed. The analysis and generalization of measures taken by Member States to eliminate findings is carried out, systematization of such measures by areas of maritime activity of the State, identification of similar aspects and approaches are also carried out. Possible measures are identified to improve the IMO Member State Audit Scheme as a whole and to implement its provisions within a single State. 

The problem of building a procedure for managing the emergency state of the ship and its resolution, as a central problem in ensuring the survivability of the ship in emergency situations is analyzed in the paper. Drawing up a procedure for managing the ship state in emergency situations, in the form of a core formalized model, is presented as a series of operations: content analysis of the emergency operation scenario; theory of ship’s damage control operation; structure formalization of the ship emergency operation as a process; logical action program of the emergency operation management procedure with a fixed goal which is represented by a matrix. If the logical operator finds that it is impossible to obtain a given goal during the implementation of the emergency operation, then the model of the emergency control procedure is extended. The extended model of the emergency procedure for managing the state of the vessel survivability contains the following additional series of operations: content analysis of the extended scenario in emergency situations; development of an extended theory of emergency operation; drawing up an extended structure of an emergency operation; descriptions of an extended operation in emergency situations as a process; drawing up an extended logical program of actions for the emergency operation control procedure with a fixed goal depicted in the form of a matrix. Finally, the algorithm (sequence) for developing a shipboard procedure for managing the state of an emergency operation within the program-target approach will be an iterative process that will ensure the achievement of the set goal — the effective implementation of a shipboard emergency operation to ensure the ship survivability, by using an extended procedure. 

The issues of selecting the number of teeth for 2k-h type A mechanisms based on the study of the known conditions for their assembly used in the development of planetary gearboxes of various shipboard both deck and main power ship installations are highlighted in the paper. Considering the design practice, when selecting the number of teeth, it is important to maintain a given gear ratio, ensure the alignment of the mechanism gears, withstand the condition of the neighborhood of satellites, ensure the assembly condition and the absence of interference of internal gearing. These conditions are expressed in terms of the number of teeth of gears and impose restrictions on the parameters of 2k-h mechanisms. Checking the interference condition of internal gearing at the stage of selecting the number of teeth in existing methods is usually not done, but it is performed at the stage of checking the quality of gearing according to geometric conditions. With this approach, the selection of tooth numbers is considered as a problem solved by the method of successive approximations: selection of tooth numbers — calculation of geometric dimensions — checking the quality of gearing — selection of a new combination of tooth numbers, etc. The condition of interference of internal gearing obtained in the work is represented by a closed formula, which eliminates the use of the iteration method, which requires a large amount of computational work and allows it to be tested at an early stage of product development. The neighborhood condition is expressed by an equation in which the design parameter is associated with the maximum possible number of satellites and a guaranteed gap between their initial circles. It makes it possible to theoretically explain well-known constructions that do not agree with the theoretical views existing at that time. The alignment condition allows for both an even and an odd difference in the number of teeth of the central wheels. Thus, the results obtained make it possible to solve the problems of creating a mechanism with the maximum possible number of satellites for reducing the size of a planetary mechanism as a unit completing a marine gearbox of any complexity, to expand the set of possible combinations of the teeth numbers that provide a given design and require less computational work. 

The samples of epoxy compound with a powder filler and without it are tested on cavitation wear. The powder of aluminum bronze BrAZhNMts9–4–4–1 is used as a filler. The powder is obtained by filing the rod of the bronze. The composition of the epoxy compound is 100 parts of the resin K‑153 plus 12 parts of the hardener (polyethylene epolyamine). The distribution of the bronze particles in the epoxy compound follows the law close to the exponential one, the average particle size is equal to approximately 27 μm, and the volume fraction of the bronze powder in the compound is about 9,5 percent. The tests are conducted using the ultrasonic magnetostrictve vibrator UZDN‑2T in fresh water of room temperature, the frequency and amplitude of the vibrator horn end equal to 22 kHz and 28 µm respectively. The distance between the horn end and the sample surface is 0,5 mm. During the experiments the wear of the samples is evaluated by their weighting on analytical scales with step-type indication of 0,1 mg, measuring the surface roughness and the microhardness of the bronze particles in the composite is carried out as well. It has been shown that the addition of the bronze particles into the epoxy compound not only changes the kinetics of cavitation wear of the polymer but also decreases its cavitation resistance. The decrease in cavitation resistance caused by bronze particles addition is attributed to the fact, that the boundary between a metal particle and epoxy matrix is a «weak» spot, and the destruction of polymer begins from this boundary area under cavitation attack.

A numerical experiment with three groups of low-consumption inflow turbine with partial blading of the runner is considered in the paper. Geometric models of turbine stages with partial flapping of the runner with different grid spacing of the nozzle diaphragm have been developed. The object of this study is centripetal turbine stages with partial flapping of the impeller. The subject of the study is the efficiency coefficient and the velocity coefficient of the nozzles of the inflow turbine. The research method is numerical simulation of the working fluid flow using elements of computational gas dynamics. The aim of the study is to determine the effect of the nozzle blade pitch on the efficiency of the nozzle diaphragm of low-consumption inflow turbine with partial blading of the runner. The main objectives of the study are creating geometric models of turbine stages with different nozzle pitch, determining the boundary conditions of the experiment, conducting and processing the results of the experiment. The graphs of the dependence of the nozzle velocity coefficient and the efficiency of the low-consumption inflow turbine stage are provided. A comparative analysis of the nozzle velocity coefficient and the efficiency coefficient of three turbine stages with different grid spacing of the nozzle diaphragm is carried out. The velocity fields of the flow part of the turbine stages and the integral values of the parameters necessary for the three-dimensional calculation are obtained. The influence of the nozzle blade pitch on the velocity coefficient of the nozzle diaphragm and the efficiency coefficient of the turbine stage is determined. The nature and dependence of this geometric parameter on the efficiency of the study object is established, conclusions on further improvement of turbine stages with partial blading of the runner are made. 

The development of a methodology for modeling the wear surface of deadwood bearings based on optical scanning is considered in the paper. It is noted that the deadwood bearings of the ship’s shaft line wear out unevenly during operation, which affects the stress-strain state of the shaft and the system parameters responsible for the occurrence of resonance of transverse, torsional and longitudinal vibrations. The methodology and results of an experimental study of bearing wear surfaces are presented. The applied optical scanning scheme makes it possible to obtain high-precision digital models of objects due to synchronous shooting of an object with two cameras. The measurement results are obtained by processing with specialized software. The results obtained are an addition to the methodology for determining the elastic force acting on the shaft from the side of a bearing that is unevenly worn along the length with a non-constant gap. Based on the obtained wear values, a solid-state model is constructed and the natural frequencies of transverse, torsional and longitudinal vibrations are determined. For the constructed model, the forms of natural oscillations for practically significant frequencies are obtained. It is noted that bearing wear affects not only the displacement of the natural frequencies values, but also the oscillations shape. The impact of the wear of the aft bearing on the bearing capacity of the shaft line, taking into account the contact interaction, is evaluated. The simulation has shown that the bearing wear surface forms an area of increased contact pressures that arise from the impact of the propeller shaft. Analysis of the propeller shaft tip has revealed the presence of an area of increased concentration of equivalent stresses formed at the place of bearing wear formation. The proposed method of modeling the deadwood bearings wear allows us to evaluate its effect on the magnitude of the displacement of natural frequencies and the change in the bearing capacity of the shaft line. The results obtained in this work are an addition to the existing calculations in the design and evaluation of the ship’s power plant reliability. 

The use of hydrogen as a fuel for tankers carrying liquefied hydrogen is discussed in the paper. As a solution to the problem of the world industry decarbonization, the possibility of competitive use of hydrogen as a fuel on sea tankers transporting liquefied hydrogen over long distances is discussed. The main reasons that encourage countries with sea and river vessels to develop in the direction of improving the ship power plants, in anticipation of tightening the national and international requirements for environmental pollution prevention, are indicated. A brief overview of the development of hydrogen energy is given on the example of leading projects in Europe and Asia, the most successful of which should include the transportation of compressed hydrogen by an experienced tanker of the Japanese company Kawasaki “Suiso Frontier” from Australia to Japan. A strategy for choosing the optimal propulsion unit for a liquefied hydrogen tanker is given. As research methods, the analysis of data obtained in similar studies, as well as the analysis of thermodynamic characteristics of promising systems, is used. Integrated power system designs and re-liquefaction systems for ocean tankers transporting hydrogen are proposed. Data on existing projects with low and high pressure gas engines, solid oxide fuel cells are given. Five prospective energy systems and a re-liquefaction system with a Claude cycle, using hydrogen and liquid natural gas as fuel and refrigerant, are suggested. Their technological feasibility and environmental impact are evaluated. The re-liquefaction systems’ exergy efficiency and specific energy consumption ranges are 26.79–46.27 % and 3–7.45 kWh/kg, respectively. A system with a low pressure engine, solid oxide fuel cells and a re-liquefaction system is determined to be optimal. 

It is noted that the requirements for the reactor installations of new atomic icebreakers of 22220, 10510, 10570 projects suggest an increase in safety (reliability), efficiency and maneuverability. At the same time, the maneuverability of reactor installations in specific features is limited and does not have an unambiguous connection with the maneuverability of the nuclear energy installation in general and rowing electric motors in particular. For this, the separate principle of controlling the reactor and steam turbine installation is implemented on the projects of atomic icebreakers. It is indicated that the development of new projects of atomic icebreakers with increased consumer properties requires processing the statistical information based on the results of the operation of atomic icebreakers of already implemented 10520, 10521, 10580 projects with various input terms and the duration of operation in the Arctic. This allows us to ensure the development of a reasonable approach when determining the operation of atomic icebreakers. It is noted that in order to compare maneuvering operating modes of reactor installations of individual icebreakers and the development of generalizing characteristics, information obtained from specific icebreakers is required. The collection of statistical data from the organized on all nuclear icebreakers and grouped materials are annually received for processing and generalization in the «OKBM Africantov». Assignment calculations are made on statistical information accumulated from 1975 to 2000 by the quantity and depth of change in reactors power when working in the Arctic conditions. A new approach to taking into account the number of equivalent cycles during maneuvering the reactor installation is proposed in the paper. In features of the existing approach with the determination of the above number of cycles in a new approach, the significance of the sublayer is taken into account by the impact on the reliability of the active zone. It is shown that this approach gives a more adequate assessment of the active zone resource expenditure during the campaign. The evaluation of the cycles density of the reactor installation power changing over the reporting period of time is also proposed. It is shown that at maneuverable operation of individual icebreakers there are an individual emphasis and increased maneuverable load of single-reactor icebreakers in relation to dual-reactor. 

Autonomous boilers, the most important element of which is the combustion chamber, are widely used in ship power plants. A necessary condition for a high resource of boilers and their trouble-free operation is the high quality of the lining of the furnace space, operating under variable thermal conditions. The quality of the material from which it is made has a decisive influence on the reliability of the lining. The methods of experimental research that can be used to assess the quality of materials for lining the furnace spaces of autonomous boilers are described in the paper. The methodology of conducting research using the method of equivalent materials is presented, laboratory installations for conducting vibroacoustic studies and modal analysis of spectrograms and thermal imaging studies of samples of lining materials are described. As a result of the research, information on the influence of conditions for the formation of equivalent materials samples on their thermophysical properties, spectrograms of the state of brickwork bricks made of various materials, thermal images of lining elements in a stationary temperature field at different locations on the heater is obtained. The results obtained indicate the expediency of using the proposed methods at all stages of the life cycle of autonomous boilers: when designing for a rational choice of lining materials taking into account operational factors, during manufacture and repair during operation to control the quality of materials used and detect hidden defects. In order to increase the effectiveness of the proposed experimental methods for assessing the quality of lining materials of boiler combustion chambers, it is necessary to expand the practice of their use, the accumulation of the results obtained and their statistical processing, which allows us to determine the error of the methods and improve laboratory installations. 

There are numerous cases when during the ship operation it is advisable to exclude for some time the intake of sea water used to cool the ship’s power plant. The issues of the possibility of such operation of widely used open double-circuit cooling systems are considered. To this end, the systems can be switched to the sea water tanks available on board. Work according to this scheme is limited by the time of heating the available water to the maximum allowable temperature. The issues of increasing this time by rising the heat removal through the ship’s plating are considered. To do this, the heated water is not simply discharged into the tank, but is jet supplied through the pipeline system directly to the inner surface of the ship’s plating. Conducted visual and thermal engineering studies have shown that the best results are achieved with the use of a jet supply, supplemented by a screen one. As a result, a channel for hot water movement is formed between the screen and the ship’s plating. Water radially spreads outward from the center of the screen, forming a fan jet. At the same time, the maximum flow velocity around the ship’s plating and the temperature difference between hot and outboard water are ensured. The advantages of this method for supplying cooled water are confirmed by the thermal engineering studies. It is shown that in this case the heat transfer increases by 25…30 %, compared with the case of a simple jet water supply. As a result of processing numerous experimental data, generalizing similarity equations have been obtained. They allow you to calculate the heat transfer for various water flow regimes. The use of these devices allows you to increase the time of systems operation in a closed loop without receiving outside water. These devices are quite simple in design and can be used both at the stage of building a new ship, and when modernizing existing ships. An example of such devices introduction on self-propelled floating cranes is given.

The aim of the study is to assess the effectiveness of automated systems related to organizational and technical systems based on the implementation of a systematic approach to information technology. To achieve the goal it is necessary to solve the following tasks: to determine the main parameters of the systems functioning quality and choose the corresponding indicators of effectiveness. Theoretical foundations of a description of the process of evaluating the effectiveness of automated control systems are considered. The most commonly used criterion (term) is profit referred to costs, i. e., costs are taken as a criterion of cost-effectiveness. The fallacy of this criterion (this fraction) can be seen from the graph of the typical dependence of the system efficiency indicator on the total cost for solving the problem using this system. A rationale for the method of evaluating the effectiveness of complex systems, which include automated control systems, is given in the paper. It is shown that the modern system of providing automated control systems must be effective without disturbing the existing mode of operation. Thus, the automated system that solves the problem with a given efficiency at the lowest total cost is selected. Despite the fairly widespread use of the efficiency indicator in the form of a fraction (profit/cost), it is not appropriate to apply it, because these estimates do not include a comparison of different ways to achieve the goal. If it is necessary to choose from a number of competing enterprises it is necessary to compare all variants at decision-making on total efficiency, and then to compare these variants on effect. That is, the system that solves the problem with a given efficiency at the lowest total cost for the development of the system, its construction and operation is chosen. Comparative economic-effective assessment of competing automated systems allows you to get the best (rational) solution (the best structure, parameters and functional characteristics of the system) designed to implement a given task in certain external conditions.