The article presents the results of the set of experiments in navigation simulator that deal with the 180º turns of double-acting ships in ice. The experiments have been carried out in accordance with a developed program for variable ship sizes, ice thicknesses, total ice concentration, and horizontal sizes of ice floes. Ship types of gas carrier "Christophe de Margerie", tanker "Mikhail Ulyanov" and container ship "Norilskiy Nickel" have been considered. Based on the simulation results, the influence of various parameters of ice and ship on the duration of turning maneuver has been assessed and the regression model for its approximate estimation has been proposed. Validation of this model with the use of full-scale AIS tracks of Arctic transport ships has demonstrated good accuracy. Typical values of the turning maneuver duration range from 0,3 to 1,0 h. The obtained regression equations can be used in modeling of ship operation in the Arctic transport systems, as well as in solutions for optimal ice routing considering different modes of ship movement in ice and corresponding turning processes.

The article presents a generalized scheme for calculating accelerations at an arbitrary point of the ship in the inertial and fixed to the moving ship frames of reference with known parameters of its motions. A practical formula for calculating the acceleration at any ship's point has been proposed, taking into account the influence of gravity when modeling the motion of a ship in irregular waves in the frequency domain. A comparative analysis of the amplitudes and modes of oscillations of vertical and transversal accelerations at an arbitrary point of the ship have been made where they were calculated using exact and approximate formulae. The article describes the main present seakeeping criteria using acceleration at characteristic points of the ship's hull as a basis, which allow for quantifying the impact of ship motions on the crew and passengers.

The paper discusses methods for assessing the characteristics of the anchor equipment used by classification societies and standards for small and high-speed craft. It is noted that most of the existing rules are based on the choice of elements of the anchor arrangement through the "equipment number", which does not allow taking into account the features of non-standard types of ships. A method of direct calculation of the anchor mass based on the effect of storm conditions on the ship, considering the given geometry of the hull and superstructure, wind speed and current has been proposed, which allows for more reliable consideration of the features of ships of different types. Using the methods of a number of classification societies and the above mentioned method of direct calculation, comparative calculations of the masses of anchors for a series of single-hull ships have been performed. The specifics of the requirements for multihull ships have been touched upon. Conclusions have been drawn about the primary factors affecting the parameters of the equipment and ways to improve the Rules.

Introduction of so-called light anchors on modern ships, or anchors with high and super high holding power, requires them to have a certificate of the classification society confirming that they are able to hold in various types of soil with an external load of at least two loads of a conventional stockless anchor, for example, a Hall type anchor. To obtain a certificate, it is necessary to conduct tests that are time-consuming and require the use of a special vessel equipped with a manipulator, crane or crane beam for hanging, dropping and selecting test anchors. Small and medium-sized firms manufacturing such anchors need alternative test methods to reduce their cost and time. The article considers the possibility of simulation tests of anchor models obtained by additive manufacturing them from ABS plastic with a non-industrial 3-D printer. The criteria of similarity of the full-scale and model process of the anchor behavior in the ground at its static position and drawing, obtained by dimensional analysis, have been given. The results of testing an anchor of a shape similar to the internationally used AC-14 anchor together with a Hall anchor of a similar mass have been presented, for which it was necessary to develop both a laboratory installation and methodology for carrying out the experiment.

The paper presents the experience of industrial application of the method of low-frequency vibration processing of the hull of the ship gearbox "RO55" in order to remove residual welding stresses. Numerical assessment of the value of residual stresses by the methods of resonant frequencies and magnetic anisotropy has been carried out with a comparison of the convergence of the results obtained. Based on the analysis of the research results, assumptions about the possibility of using low-frequency vibration treatment as an alternative to thermal annealing of welded hull structures of marine engineering products have been formulated. The results of the work can be used in production of large-sized welded reverse gears of dual-purpose ships to determine the magnitude of residual stresses and assess the stability of the geometric dimensions of the product. The proposed technology can significantly improve the technological cycle of production by reducing the time of operations, eliminating a number of logistics movements, as well as forgoing the use of specialized expensive equipment.

The article provides a comparative analysis of the requirements of classification societies and industry standards for welded socket joints. The geometrical parameters of coupling joints, regulated by various normative documents, have been determined and compared. Numerical experiment has been carried out by calculating the finite element stress-strain state in a joint loaded with various operational loads. The data obtained indicate that the stress concentration factor in the weld increases slightly with an increase in the diameter of the pipes being connected, and thus the scope of welded socket joints can be expanded. The allowable diameter for the use of welded socket joints in class II pipelines can be increased subject to certain additional requirements, which are formulated in the article as a prospective normative proposal to the RS Rules.

The article considers comparison of parameters in feed regulation of centrifugal and a screw pump with bypass method via discharge characteristics to determine the ship tanks stripping efficiency. For comparison assessment of parameters, the scheme with annular bypass pipeline has been used. The comparison has been made for two regulation modes: with full-opened and half-opened bypass valve. The capacity and it is regulation range for full-opened and half-opened valve are higher for centrifugal pumps. In case of short tank stripping time in relation to main pump work mode the deciding factor is stripping time, meaning the efficiency of pumps can be neglected. Based on comparison of centrifugal and screw pumps parameters working on main mode and stripping, the preference has been given to centrifugal pump. Its disadvantage is in lack of self-suction, which is resolved with technical devices, removing air prior to entering the pump while stripping.

The article describes the historical path of Russian Maritime Register of Shipping (RS) rules development regarding the tightness of nuclear steam supply containment system as applicable to nuclear ships and floating facilities design and testing. The proposals for the amendments to the RS documents are based on research results and data obtained during testing of three nuclear-powered icebreakers (project 22220) and floating power plant. The main proposals are as follows. Relative leakage rate at pressures up to value relevant to maximum design-basis accident (DBA) depends on different factors, so it is reasonable to obtain its values during the main test at DBA pressure as it has been done while the construction of nuclear-powered icebreakers project 22220 and floating power plant was in progress and the extrapolation of the results from low pressure tightness test is not acceptable. The allowed relative leakage rate for control test shall be obtained during the main test at specified low pressure in containment system. These proposals would bring the RS documents into alignment with actual practice of testing of nuclear steam supply containments system as applicable to nuclear ships and floating facilities.

The article summarizes results of formalization, analysis and system of breakthrough technologies of creation and operation of marine automated systems in protected version (MASPV) in the context of previously formulated priority technologies for the development of ship energy as part of critical technologies of the Russian Federation. Based on the analysis of their priority and breakthrough technologies, the completed foresight analysis of trends in the integrated development of MASPV allows us to identify new research methods and technologies with one-time search and synthesis of promising design solutions to ensure priority of development, military-technical superiority and competitive ability of MASPV-co-created warships and civil ships.

Ships annually consume more than 330 million tons of fuel. However, marine fuels, compared to aviation and automotive fuels, are much less purified. International Maritime Organization (IMO) has implemented strict regulations on the sulfur content of fuels and established emission control zones in the coastal waters of some continents. About 70 % of traditional marine fuels in Russia currently used in shipping, especially in the Arctic region, need to be modified or replaced. Third-generation fuels, biofuels, can be such a prospective replacement. Studies of various characteristics of marine diesel engines using biofuels of various origins and their mixtures in different proportions with diesel fuel have shown a significant reduction in almost all types of emissions. High production cost is one of the essential factors impacting the active use of algae biofuels. The present article provides analysis of the conditions for growing different types of algae in Russia.

Intensification of cargo transportation by sea in the Arctic region puts forward new requirements for the designed ships intended for operation in the North conditions. Ships operating in the Arctic region shall be specially designed to meet the requirements for navigation in ice conditions. It is necessary to ensure the required characteristics of ice-going capabilities by designing hull forms that meet these requirements. In addition, their power plant shall meet modern requirements as to regulating the amount of harmful emissions and have low fuel consumption, maneuverability and energy efficiency. For a preliminary efficiency assessment of the ship's operation in ice, it is necessary to determine the relationship between the parameters of the energy efficiency and the characteristics of ice-going capabilities. This paper proposes a method for determining the coefficient expressing this relationship for ships of various types operating in ice navigation conditions. The coefficient, in the future, will allow for a comprehensive comparison of the operation efficiency of existing ships in ice navigation conditions, as well as for assessment of newly designed ones.

The article shows the scope of application of thermally expanded graphite as a sealing material in various industries, including shipbuilding, due to its consumer qualities that other carbon materials do not possess: elasticity and plasticity. The relevance and timeliness of the active development of this area of scientific and technological progress are dictated by the requirements of environmental safety. The description of the physical and mechanical and antifriction properties of seals made of thermally expanded graphite has been given together with the examples of specific products. The main technical advantages of new sealing materials made of thermally expanded graphite have also been described. The research methodology has been given, including a description of a device for studying the antifriction properties of seals made of thermally expanded graphite and other materials. Furthermore, the main elements of the device and their functional purpose have been described in detail. The results of studies of the anisotropy of the thermally expanded graphite seal antifriction properties have been presented. It has been established that the friction force of the surfaces of real thermally expanded graphite seals f on steel depends on the direction of movement.

The article discusses the research of adhesive strength of composites based on polyamide matrix. Possible options for controlling the adhesion of the composite on the steel and the formation of an antifriction layer have been considered. The article structurally consists of three parts. In the first part, methods for determining adhesive strength have been considered. The method of testing has been substantiated and theoretical justifications for the applicability of the thermal fluctuation theory of the strength of adhesion of the composite to a metal substrate have been given, making it possible to predict the durability of the adhesive joint. In the second part, the technology of preparing the metal polymer charge for melting has been considered and the classification of methods for processing the composite into products has been given, depending on the size of the filler particles. The third part of the article is devoted to testing the adhesive strength of polyamides of various brands serving as the basis for the creation of composites. The influence of aggressive media and operational factors of the change in adhesive strength have been studied. The study of adhesive strength shows that the optimal preheating temperature of the part depends on the type of polymer. In practice, it depends on the metal content of the polymer-coated product. Finally, the technology shall be selected for each specific part, with the obligatory condition of applying the polymer at an optimal temperature.

The article discusses correspondences for calculating the parameters of the thermodynamic cycle of the Stirling engine. Heat transfer in the working cylinders has not been taken into account in accordance with the accepted hypothesis. The developed method makes it possible to calculate the pressure value in the cycle with an accuracy sufficient for engineering calculations. Comparison with the reference calculation showed an error in determining the pressure in the cycle by a standard deviation of 0,19 % of the average pressure of the cycle. The error in determining the indicator power was 0,6 %. The method is intended for calculations of the thermodynamic Stirling cycle for engineering purposes. In the development of various systems of Stirling engines, for example.

One of the most stressful and responsible elements of marine gas turbine engines are the working blades of axial compressors. Their breaks are the cause of severe emergency damage. An effective means of reducing the likelihood of such accidents is monitoring the main factor contributing to the accumulation of fatigue damage to the blades — the amplitude of their oscillations. The article presents the results of simulation modeling of contactless measurement of the amplitude of bending vibrations of compressor blades by discrete-phase method. It has been shown that the discrete-phase method makes it possible to obtain sufficiently reliable estimates of the amplitude of the blade oscillations, at which when multiplied they can lead to significant methodological errors.