Many shipbuilders believe that there is an unambiguous correlation between class notation signs and the main characteristic of ship propulsion in ice, i.e. the limiting ice-going capability (speed vs ice thickness). This paper analyses current RS rules to bring to light this relationship. It is shown that the ice class notation sign may only correlate with the limiting ice-going capability if the minimum horsepower of the ship powerplant required by RS is taken into account. The analysis is performed for generic ice-going vessels with typical principal particulars and bow shapes. The study results show that it is not possible to predict the limiting ice-going capability based on the relationship of ship characteristics under consideration, therefore it cannot be used in the ship design process.

The article presents a system of ice restrictions developed based on the experience of classification of ice-going ships. The presented ice restriction system is designed to determine the ability of a ship to navigate in certain ice conditions, depending on its ice class, based on a risk assessment and can be considered as an alternative to the POLARIS system proposed by IMO. Unlike the POLARIS system, the proposed system includes the ice classes of the Russian Maritime Register of Shipping, which eliminates discrimination and allows the use of ice classes of any classification societies, including the IACS classes and the Finnish-Swedish ice classes. The author relies on an approach that involves determining the risk parameters of ice navigation, in which the risk of ice damage is equal to or less than the risk value that occurs when sailing in the ice conditions allowed by the classification society, which are accepted as standard for this ice class of ship. The proposed system is regarded as intermediate between a system based on risk assessment and a methodology based on strength calculations implemented in ice passports, which are practiced by the CNIIMF and the Register. In the proposed system, the author has tried to use the advantages of both approaches, avoiding their disadvantages as much as possible. The purpose of the article is to present the developed system of ice restrictions for discussion and further verification of its adequacy both in real conditions and using simulation methods. The author hopes that the proposed system may be of interest to both shipowners and the NSR administration, and its application will avoid severe restrictions on ice navigation depending on the date and geographical area.

The article addresses part of the STCW Convention requirements for maritime administrations' obligations regarding quality standards system of seafarer training. The work provides an overview of the implementation of these requirements by the Maritime administration of the Russian Federation and a brief review of their changes over the past 15 years. The problematics of the STCW requirements implementation is pointed out at different levels — maritime administration and specific organizations. Based on the information on the audits successfully undergone by the Maritime administration of Russia, the ways to consolidate positive changes in the methods of STCW requirements implementation are proposed.

Recent decisions by the International Maritime Organization to reduce greenhouse gas emissions from international shipping pose significant challenges for both ship propulsion system developers and shipowners, who will jointly seek ways to transition to alternative fuels, and for maritime educational institutions, which must train specialists for this rapidly changing industry. This article examines the latest IMO decisions on a long-term strategy for reducing carbon dioxide and other greenhouse gas emissions, adopted by the Marine Environment Protection Committee. A brief analysis of the changes in shipping caused by the adoption of this strategy is provided. Basic requirements for training programs to be developed for the appropriate certification of seafarers expected to serve on ships using alternative fuels are also discussed.

With the increase in the number of operations in freezing sea ports of the Russian Federation, and given the ability to provide bunkering with liquefied natural gas, the question of the expediency of using dual-fuel tugs is becoming important. In the absence of regulatory restrictions on the use of low-sulfur marine fuel, the issue of using natural gas can be resolved using the economic criterion of expediency. This approach relies on implementing economic models that need a certain set of input data about the tugboat for calculations. The study of the "ice" Rules of the Russian Maritime Register of Shipping, as well as the ice thicknesses characteristic of the Gulf of Finland in navigationally difficult winters, demonstrated the need to use tugboats with the arctic ice category. In the absence of a dual-fuel tugboat with an ice class sufficient for safe year-round operation in the waters of freezing ports, the authors created its mathematical model based on statistical data on tugboats with ice classes Arc4 and Arc5 and giving an idea of the design characteristics of this vessel in the first approximation, which is sufficient for conducting a feasibility analysis.

Thus, the object of the study is a mathematical model of an Arc5 ice-class LNG-fuelled tugboat, and the purpose of the study is to assess the impact of dual-fuel technical LNG solutions on the appearance and main characteristics of an Arc5 ice-class barthing tugboat.

The low vibration and low noise of the engine piston as a whole is ensured by a special U-shaped insert due to the calculated vertical-axial and horizontal-lateral elastic deformations of the insert springs, and the connecting rod by perforation in the rod. During ignition and combustion of fuel, the rod is elastically compressed, providing a change in the degree of compression, due to which mechanical loads on engine parts are reduced. In order to determine the effectiveness of ensuring low vibration and low noise of the piston and connecting rod, we have now started developing drawings for the manufacture of prototypes for two objects: the piston compressor 4122-210 (an analog of the Knorr-Bremze product), the braking system of a KAMAZ car and a 1H8.5/11 diesel engine. Experimental studies are planned to be conducted in the laboratory of marine internal combustion engines and diesel installations of St. Petersburg State Marine Technical University (SPbGMTU) as part of the Master's and then PhD theses. On the basis of the 4122-210 compressor and the 1H8.5/11 diesel engine, it is planned to create special universal experimental installations to evaluate the effectiveness of vibration and noise reduction tools not only at the source of occurrence, but also on the distribution routes, that is, non-traditional elastic suspensions of pipelines, supporting and non-supporting connections (shock absorbers and elastic couplings). One example of the adoption of support shock absorbers with an elastic cable element is their implementation on two refrigerated vessels of the Ivan Kulibin series in the DGA-500 amortization system with a 5AL25 drive diesel engine. These and other examples related to the problem of reducing vibration and noise on ships can be found in the publications of MAMSar authors.

The article analyzes the real dynamics of changes in the use of various types of marine propulsors, relying on the open technical data of ships classified by the Russian Maritime Register of Shipping. The purpose of this article is to identify trends in the development of marine propulsion systems and their use on Russian ships. The article notes the trend of complete replacement of Voith Schneider propellers with azimuth thrusters. As a result of the analysis, a trend has been identified to expand the use of azimuth thrusters on marine ships of various purposes, with the exception of high-speed vessels, fishing vessels and large displacement transport ships without ice class, and the reasons have been identified for the refusal to use azimuth thrusters on ships of these type.

The article is devoted to the development of a mobile software and hardware complex for measuring the power of outboard motors in full-scale operating conditions of small vessels. The relevance of the work is due to the systematic underestimation of the rated power by the manufacturers of outboard motors, which increase the risks of accidents. To solve this problem, the staff of the scientific, educational and production laboratory for outboard motors of the Department of Water Transport Operations and Industrial Fisheries of the Astrakhan State Technical University conducted research and development works, which included the development of a mobile device for measuring the power of outboard motors in field conditions. The device is based on the principle of operation and mathematical model used in the previous project of the department — the stationary rig "Small experience pool" (utility model patents RU 196596 U1, 03/06/2020 and RU 182049 U1, 08/01/2018 [1;2]). The main objectives of the scientific work were the development of a mobile software and hardware complex for measuring the power of outboard boat motors; creation of a physical model of the device; software development; experimental testing on the basis of a model basin and field tests in the waters of the Volga River; carrying out the processing of test results, comparing the data obtained with the declared power of outboard motors and preparing a preliminary and final report on the R&D carried out. In the course of the work, all the tasks were solved and, within the framework of the R&D contract, a device was created with which it was possible to determine the power of both outboard and stationary power plants of small ships. This article describes the composition of the device, the climatic conditions of use, the test program for outboard motors using the device, and some test results.

This paper presents a new diagnostic algorithm for the early detection of faults in the data-measuring channel of inductive speed sensors used in low-speed marine internal combustion engines. Unlike traditional methods based solely on signal presence or amplitude thresholds, the proposed approach involves a two-parameter analysis combining the temporal and frequency characteristics of the sensor output signal. Specifically, the algorithm continuously monitors two key parameters: the duration of individual pulses and the number of pulses accumulated over a fixed oneminute interval. Thresholds for these parameters, set within a pulse duration range of 50 — 200 ms, are determined based on the engine speed operating range, corresponding to stable idle running and maximum load. Deviations beyond these limits trigger an alarm, indicating potential sensor degradation, electromagnetic interference, or mechanical failure. The algorithm is implemented in the CODESYS 2.3 environment using standard programmable logic controller (PLC) function blocks, ensuring compatibility with existing marine automation systems and enabling seamless integration without hardware modifications. The auxiliary simulation module simplifies autonomous validation by emulating realistic sensor signals under both nominal and fault conditions. The developed solution improves system reliability by enabling the timely detection of latent faults that are often undetectable by traditional self-diagnostic mechanisms, thereby enhancing operational safety, reducing unplanned downtime, and supporting condition-based maintenance strategies in marine environments.

The article considers the studies of the problem of mechanical losses on the drive of auxiliary mechanisms of diesel engines carried out at the Department of Water Transport Operation and Industrial Fishing of the Astrakhan State Technical University. The design of the test bench, measuring equipment, test results, and prospects for further research are described.

This article analyzes modern methods for reducing mechanical losses in auxiliary drives of diesel engines, including a review of Russian and international research. Approaches such as the use of electromagnetic clutches to regulate the operation of cooling pumps, variable-displacement pumps, and drive decentralization are considered. Developments at Astrakhan State Technical University are described, including experimental rigs with variators for smoothly changing the pump speed. Test results demonstrate a 30 — 50 % reduction in power consumption (from 1000 W to 300 — 628 W), fuel savings of up to 20 %, and an increase in thermal efficiency. The relevance of this approach for improving the efficiency of marine engines and reducing emissions is emphasized.

In the work, the authors identified problems in the operation of the external circuit of the cooling system for marine power plants and auxiliary equipment for navigation in shallow-water routes of the Caspian Sea and the Volga-Caspian shipping Channel. The design and installation of a laboratory stand for water purification from mechanical suspensions by a hydrocyclone in the laboratory of shipboard boiler installations and automation of the Department of Operation of Water Transport and Industrial Fisheries of Astrakhan State Technical University was developed with the solution of automation and control tasks to ensure uninterrupted automatic operation. Laboratory tests of the developed stand were performed using rolled calcined quartz sand as a coarse impurity in the source water being treated with a hydrocyclone. According to the results of a laboratory study, the effectiveness of the sludge collector retention of a hydrocyclone of mechanical suspensions was determined. The analysis of experimental and theoretical studies of scientific and technical literature has allowed us to develop an initial methodology for the hydraulic and structural calculation of the hydrocyclone chamber, which makes it possible to calculate hydrocyclones for the ship's system of the outboard cooling circuit of the "Atlantic Supporter" platform supply vessel, as well as a schematic diagram of the modernization of the outboard cooling circuit of this vessel.

A comprehensive experimental study of the wear of marine diesel engine exhaust valves using various types of fuel and protective heat-resistant coatings has been conducted. The work combines field tests on OTA-900 project vessels and laboratory experiments on a 6ChN 18/22 engine under controlled conditions.

The methodology involved a comparative analysis of valve defects after successive operating cycles on heavy fuel oil (HFO), HFO with magnesium additives, and marine gas oil (MGO). Laboratory tests were conducted in parallel using an original scheme that eliminated the influence of accumulated damage.

The results revealed a significant dependence of wear intensity on the type of fuel. The greatest degradation was observed when operating on HFO without additives — pitting corrosion, abrasive wear of 120 — 150 µm over 200 operating hours. The use of magnesium additives reduced wear by 35 — 40 %, while switching to MGO reduced it by 70 — 75 %. Protective coatings demonstrated consistent effectiveness, reducing wear by approximately 20 % regardless of the fuel type.

Based on the experimental data, conceptual requirements for a methodology of accelerated corrosion-erosion testing have been developed, allowing for the quantitative separation of the contributions of chemical corrosion and mechanical erosion. The promise of an integrated approach combining modern fuels, protective coatings, and additives for significantly increasing the service life of exhaust valves is shown.

This article presents an analysis of the current infrastructure of 17 yacht marinas and boat bases in the Perm Krai within the Kama River basin. Using the authors' own approach, the infrastructure was analyzed across 25 criteria (accessibility and equipment of berthing facilities, service, transport and tourist accessibility, safety, etc.). The authors identified the leaders (Kabelshchik, Volna, Pirs, Favorit, and Polyana) and key limitations: navigational obstacles and a lack of sanitary and household amenities, Internet access, quality food service, and information in open sources. Priority development measures are proposed: the creation of a unified digital portal, modernization of service offerings, and the development of yacht routes to natural attractions. This will help realize the region's recreational potential and increase tourism's contribution to the gross regional product.