The article analyzes technical condition of engines of fire trucks operated in the territory of the Russian Federation and the requirements for the technical standards of their environmental safety in relation to the conditions of production (certification upon release into circulation) and operation in Russia. Science-based concepts, technical and technological solutions to ensure standards for pollutants and greenhouse gases of fire engine engines have been presented. As a strategic direction for improving their ecological state in operation, a concept based on the technology for diagnosing the technical condition of engines according to the analysis of the composition of exhaust gases, their neutralization at the outlet and the use of water-fuel micro-emulsions of diesel fuel stabilized surfactants has been proposed. It has also been shown that the implementation of the proposed solutions increases safety by two environmental classes.

The article contains analysis of the new Strategy on the reduction of GHG emissions from ships adopted by the International Maritime Organization in July 2023. Main changes comparing to the similar document of 2018 in particular regarding the levels of ambition to decarbonize the international shipping and proposed practical candidate measures have been highlighted. Potential problems and questions arising from the implementation of the IMO Strategy 2023 by means of development of new MARPOL requirements and scheduled revision of the existing requirements on operational carbon intensity of ships have been outlined. Main outcomes which relate to the possible effect of the IMO Strategy 2023 on the IMO activities to develop legal international framework for shipping in near and distant future as response to climate change have also been presented.

The paper deals with the issues of determining the carbon footprint of transport services when using ships with an ice class operating on Arctic routes. The aim of the study is to identify alternative methods for assessing the constructive coefficient of efficiency of ice ships for its further use for corporate accounting of carbon units, determining the carbon footprint of a transport service, as well as assessing the impact of weather conditions along the Northern Sea Route on the carbon footprint left by a ship passed from the Gulf of Ob to the eastward during summer and autumn. The study provides recommendations on the use of methods for calculating the carbon footprint of a transport service, based on the constructive coefficients of the energy efficiency of ships, allowing the use of the methodology for solving problems of planning the activities of transport companies aimed at modernizing the fleet and deriving profit from the set of core activities and participation in the newly formed trade in carbon units.

At present, coal still has an important role in the global economy. According to the current consumption rate and estimates of coal reserves in the world, its reserves will be used up in 200 — 250 years. Its share in the world consumption of fuel and energy resources is currently about 30 %, and up to 40 % of the world's electricity is produced by coal power plants. However, there is a number of environmental, economic and technological problems associated with the use of coal in the energy sector. Their solution is the improvement of the technology of coal mining and enrichment, as well as the development of new environmentally friendly fuels based on it. One of such fuel type is a coal-water one. The article presents the results of numerical simulation of the combustion of coal-water fuel in a ship's low-capacity hot water boiler. The model has been created in the ANSYS Fluent software package, based on the developed mathematical model of the processes of hydrodynamics, heat and mass transfer, as well as the kinetics of thermochemical fuel transformations during the combustion of coal-water fuel. Various options for the operation of the boiler have been analyzed, which make it possible to provide modes of both solid and liquid ash removal to ensure low harmful emissions into the environment.

The article discusses the issues of the design of external structural protection (ESP) from the ground on the example of a non-selfpropelled tanker barge. The relevance of constructive protection of hulls under conditions of contact with the ground was shown. The experience and damage of ships during interacting with the ground were generalized. Schemes of local ESP have been developed. Study of the stress-strain state of structures by the finite element method for two design scenarios was performed. The implementation of the proposed protection scheme makes it possible to reduce the level of hull damage and to increase its durability in operation.

The article considers the applicability of shipbuilding steels regarding crack start resistance. Probable correlations of impact energy vs. fracture toughness parameters have been analyzed. A partial change in the application of the provisions of the IACS unified requirement (UR) S6 has been suggested.

The article touches upon the fact that poorly executed alignment of the ship's shafting during the construction or repair of the vessel often leads to its destruction, which is fatigue-like. In some cases, ensuring the alignment of all shafts and bearings also does not guarantee against premature destruction of the elements of the shafting. The main factor determining the durability of the shafting is the stress state of its material. The versatility of the loads acting on the shafting and the complexity of their determination do not allow us to obtain the stress state of the material by calculation with the necessary accuracy. It has been proposed to use the capabilities of a modern instrument base to monitor the stress state of the shafting, an example of such use has been given.

The article considers the method of determining the cost of equivalent-cyclic tests that confirm the required mean time between failures (MTBF) of a ship's gas turbine engine (GTE); with failure eliminated in operation and providing a given probability of failure-free operation of the gas-gas turbine unit. Comparison of costs for different variants of GTE and variants of the power plant based thereon have been carried out. The methodology for calculating the failure-free operation of a combined or all-mode gas turbine unit has been developed using a reliability model based on a continuous homogeneous Markov chain, for which the system of differential equations of GTU reliability — the system of Kolmogorov equations — has been solved. Recommendations have also been given for determining the number of gas-hours to be worked by the GTE during preliminary tests and (or) pilot operation to ensure the required MTBF with a given confidence probability. An example of probability calculation for failure-free operation of GTU has been given.

Torsional vibrations, despite all the design and technical solutions used, remain the cause of dangerous accidents of ship engine-propulsion systems (EPS). The use of dampers reduces the risk of torsional vibrations, but the dampers themselves must be periodically subjected to a technical condition assessment procedure to check the effectiveness of their work and the absence of structural damage. Such procedures are carried out every 10000 — 15000 h and during the inter-inspection period there is a risk of an accident in the event of a damper failure. The study proposes to carry out continuous (or with short breaks) monitoring of torsional vibrations and move on to assessing the actual technical condition of dampers instead of that according to regulations. The purpose of the study is to increase the safety of navigation and reduce the risks of fatigue failures of the elements of the EPS due to the development of dangerous torsional vibrations by implementing systems for monitoring them. The study has a practical application and is ultimately aimed at a comparative analysis of data obtained by short-term measurements of torsional vibrations using traditional systems and long-term measurements using the experimental model of the torsional vibration monitoring system developed by the authors. As objects for research, the laboratory stand of the MTS testing center of the Federal State Budgetary Educational Institution "ASTU", the marine bunkering ship of the "Turcas" project and the sea tug of the Damen ASD Tug 3110 project have been used. The results of the study show that the monitoring of torsional vibrations allows us to obtain more complete information on the development of torsional vibrations at non-resonant frequencies, at transient modes of starting and stopping the ME, compared with the information obtained with the traditional torsiography procedure. The introduction of torsional vibration monitoring systems, therefore, will improve the safety of navigation of ships and reduce the risks of accidents with EPS.

The article presents the acomplishments of the work of JSC "Shipbuilding & Shiprepair Technology Center" Design Bureau "Armas" employees, who have developed a product line of small-size ship non-return valves. For the purpose of presenting the object of study, the authors give a general view of the classical design and the alternative design of a general view of small-size ship non-return valves. The simulation of fluid dynamics, which is a power fluid "water" in normal climate conditions and a power fluid hydraulic drive in negative temperatures, in a flow channel of small-size product verifies ability of mechanical design to proper function. The authors present the results of prototype testing. The comparison of a graph of hydraulic resistance in power fluid hydraulic drive in minus temperatures estimated by a numerical method and the result of the verification test in site proves the validity of the use of the numerical method. End products DN 10 have been delivered to JSC "PO "Sevmash"" for project 03660 "Yason" underwater vehicle developed by the Malachite Design Bureau.

The article presents an analysis of various regulatory documents (ISO and GOST R standards, industry standards of the oil and gas industry and shipbuilding, Rules of classification societies) in terms of requirements for pipeline vibration control. Requirements for vibration control of ship pipelines have been developed and formed. The norms of permissible vibration of ship pipelines are proposed based on the calculation of stresses arising in the pipe during its oscillations. "Methodological recommendations for monitoring the vibration of ship pipelines" have been developed for inclusion in Section 8 "Systems and Pipelines" of the Guidelines for Technical Supervision of the Construction of Ships in the form of an Appendix. Methods of control and criteria for assessing the vibration of ship pipelines during acceptance and operation of the vessel have been established. The estimation of the magnitude of variable mechanical stresses occurring in pipelines when the threshold values of permissible vibration norms proposed in the developed methodological recommendations are reached.

The article considers the issues of digitalization technology of monitoring and management of production processes in shipbuilding. The levels of management of industrial enterprises have been described. The possibilities of using automated monitoring of production processes based on IoT technology (industrial Internet of Things) have also been considered. The difficulties of implementing digital forms of monitoring and management at various stages of the production cycle of the construction of ship orders have been analyzed. The properties and features of RFID technology have been investigated. Possible ways of using RFID technology for monitoring technological processes in shipbuilding at the stage of formation of ship systems in order to minimize costs and improve the efficiency of management decisions, have been given. The main criteria for the development of a management model for complex production processes of a shipbuilding enterprise using RFID technology based on the methodology of qualimetric analysis of management quality criteria have been determined.

This article is related to the definition of the ECG block module with TPTE and its main equipment. The article considers schematic design of the block module of an electrochemical generator with a solid polymer fuel cell for an air-independent power plant and technical solutions and principles of construction, ensuring the performance of an electrochemical generator of functional purpose. The article provides a brief description of the BTE-50K fuel cell battery with a capacity of 50 kW, as well as the functional purpose and principle of operation of its main elements, while presenting a technical description of the ECG unit-module systems, including electric power conversion and switching systems (SPCE), designed to provide electricity to consumers for their own needs of the ECG unit equipment. A model of the layout of the block module of an electrochemical generator and service systems has also been presented.