Introduction. Wagon turnover time change is commonly estimated by the location of wagons at sites, technical stations, public and non-public railway tracks, in local downtime. Experience shows that exclusive use of these data leads to inaccuracies and errors. The purpose of the study is to propose a new refined methodology for analysing the indicator of the wagon turnover time, and to show the influence of the calculated parameters included in it. The application of the methodology would allow to develop effective measures to accelerate turnover and improve the quality of the transportation process.

Materials and methods. Statistical data of railway transport operations for freight transportation in 1995–2024 are used. The main theoretical results are obtained based on algebraic transformations of dependencies linking the change in wagon turnover time with the change in the values of calculated parameters in various time periods.

Results. The authors developed a methodology for determining the change in wagon turnover time with in-depth details for various calculated parameters, which is used to analyse the influence for each of calculated parameters on the change in wagon turnover time in 2010–2024 for railway network. This period in characterised by the transition from stable values of the wagon turnover time with a general downward trend to a period with significant fluctuations with a significant upward trend, approximately in 1.5 times. This caused an increase in the required car fleet by more than 350 thousand wagons, excessive occupation of station tracks and difficulties in train traffic passage. The share of each calculated parameter in the growth of wagon turnover time and their rating for reducing the impact on the overall indicator have been established.

Discussion and conclusion. The developed theoretical proposals allow for a more accurate assessment of the causes of changes in wagon turnover time and provide a basis for making decisions aimed at improving the operation of proving grounds and railway network as a whole.

Introduction. Due to the redirection of key logistics flows in Russia to the East (Asia Pacific), increasing throughput capacity of the Trans-Siberian Railway is an urgent task. Addressing this challenge requires a comprehensive assessment of the state of railway transport infrastructure facilities. The aim of this study is to analyse the operational characteristics and determine the maximum throughput capacity of the railway station located in a mountain-pass section of the TransSiberian Railway, which acts as its bottleneck. The authors proposed and applied an original comprehensive tool for railway station operation modeling, which enables to increase the reliability of the research results.

Materials and methods. Simulation was employed as the main research tool. In order to enhance the reliability of the results, two alternative approaches were applied. The first is based on the use of AnyLogic software. The second relies on queuing theory, with the development of the authors’ own software and algorithmic framework.

Results. Two complementary simulation models were developed and used to conduct computational experiments. Based on the results, a scenario analysis of the station operation was performed, including the determination of efficiency indicators for various headways.

Discussion and conclusion. It is established that the considered station is capable of handling train traffic with headways of 11 min or more. Station reconstruction would be required to reduce it. The queuing theory mathematical apparatus may be used to study railway stations operation, which reduces the complexity of model construction and analysis.

Introduction. Freight car fleet is a crucial production and economic asset for railway transport. Its effective utilisation is a major focus in both industry research and practical applications. Therefore, a relevant analysis of freight car utilisation is essential for developing strategies to improve it in modern environment. This, in turn, necessitates refining the methods used to evaluate the effectiveness of the freight car fleet. The purpose of the article is the analysis of existing approaches to assessing the use of freight cars and proposal development for its improvement.

Materials and methods. This paper examines the conventional approach to evaluating freight car utilisation and alternative approaches proposed in academic literature. The article emphasizes the need to enhance the methodological tools used for assessing freight car utilsation.

Results. A novel approach to assessing freight car utilisation is proposed, using the “temporal capacity of freight car mileage” indicator. Component and marginal analysis of this indicator is conducted, considering data from a long-term historical perspective.

Discussion and conclusion. Comparison of the dynamics of the temporal capacity of freight car mileage with other indicators of car fleet utilisation reveals that the new indicator effectively reflects the actual acceleration or deceleration of freight car turnover. Its application enables an accurate evaluation of the freight car fleet utilisation and the potential for improvement. This necessitates improvements in car flows organisation and implementation of innovative technologies for station and train operations. Simultaneously, a decrease in the temporal capacity of freight car mileage may serve as a cost indicator for implementing identified improvements and as a benchmark for evaluating the success of these strategies.

Introduction. In this article, a study was conducted focusing on the investigation of fatigue fracture characteristics of elastic clamps used in railway fastening systems, which were subjected to fatigue tests following standard and accelerated methodologies. The problem of improving the quality and extending the service life of rail fasteners, particularly elastic clamps, has become the most acute at the present time. The reason is the development of high-speed and heavy train traffic. In operation, the elastic clamp perceives preloading by mounting force and dynamic loading by cycles of preloading and partial unloading due to the impact of rolling stock. Fatigue life is the most important parameter determining clamps reliability and train safety. The purpose of this study is to analyse the main mechanisms of fatigue fracture of three clamps tested under various cyclic loading modes (according to standard and accelerated test methods) by examining fatigue fracture surfaces.

Materials and methods. The elastic clamp CP 369.102 (clamp ZhBR-65) was chosen as the object of the study. The tests were performed using both the standard method that meets the requirements of GOST 33186–2014 and the accelerated Locati method. Fractographic method was used in the analysis of clamps fatigue fracture surfaces.

Results. The similarity of processes leading to fatigue fracture has been established for clamps tested using standard and accelerated methods. A fractographic analysis was conducted on the fatigue fracture surfaces of three elastic clamps. An analysis of the fatigue fracture mechanism is provided for each clamp. For the clamp tested by the standard method, a non-metallic inclusion was found at the crack initiation site.

Discussion and conclusion. In all studied cases, the fracture of the clamps was accompanied by the initiation of fatigue microcracks originating from inclusions or defects on the lateral surface (the rod surface of the clamp). Current standard does not normalise contamination with non-metallic inclusions intended for the manufacture of clamps. It is reasonable to conduct additional studies in order to assess the influence of non-metallic inclusions in the steel on the fatigue durability of the clamps.

Introduction. The thermal performance of the passenger car body is strictly regulated, their deviation from the norm leads to a significant excess energy consumption, which is reflected in an increase in the cost of passenger transportation. Over time, due to different operating conditions and ranges, the value of the heat transfer coefficient becomes individual for each production carriage body and heat losses through carriage body guards. The purpose of the article is to develop a new methodological approach based on the heat transfer coefficient of enclosing structures, which would enable to assess the thermal condition of the carriage body with less labor intensity, more quickly and both during the factory production of the car and after its commissioning.

Materials and methods. Calculations of the values of the heat transfer average coefficient of the enclosing structures of the carriage bodies at train stand were performed based on the results of thermal engineering tests of passenger carriage bodies using the standardised method of equilibrium modes, as well as the method of nonequilibrium modes.

Results. Comparison of the calculated values of the heat transfer average coefficient bodies of four passenger carriage bodies, obtained as a result of a series of thermal engineering tests using a standardised method with similar values calculated according to the method of nonequilibrium modes, did not exceed 3%.

Discussion and conclusion. When conducting thermal engineering tests of passenger carriage bodies based on the method of nonequilibrium modes, the value of the average heat transfer coefficient of the enclosing structures of the car could be determined in production conditions in 11 h without compromising accuracy, which is 7–8 times faster than the currently used standardised method. The use of nonequilibrium mode methods enables to organise control of the normative thermal technical indicator of the carriage body after car commissioning throughout the life cycle, which gives opportunities for planning the volume of car fleet energy consumption.

Introduction. In the context of the global digital transformation of railway transport and the transition from discrete parameter recording to the creation of digital twins of energy systems, it has become increasingly critical to implement systematic modernisation of Automated Information and Measurement System for Commercial Electricity Metering of JSC “Russian Railways”, in order to close technological gaps and ensure predictive control of energy consumption and the technical condition of equipment. The purpose of the work is the development and theoretical justification of the target architecture for a unified model of a digital platform integrating functions of legally significant commercial metering, predictive analytics (forecasting of electricity consumption and equipment failures), interaction with corporate systems, and external intelligent power grids.

Materials and methods. The research is based on a systematic analysis of the architectural-functional structure of the existing Information and Measurement System. Methods of structural modeling, comparative analysis of accounting subsystems and metering equipment fleet were used. Regulatory and legal framework was analysed, and a critical review of scientific publications was conducted.

Results. The study identified key limitations of the existing Information and Measurement System: technological fragmentation, diversity of equipment fleet, insufficient level of reporting automation. Weak integration with the corporate software environment and low rates of adaptation to the concept of intelligent power grids were noted. The current infrastructure does not provide monitoring of energy distribution from source to consumer and lacks predictive analytics functionality. The obtained results served as the basis for forming the target model of a unified digital platform. A four-level architecture for the system is proposed.

Discussion and conclusion. The necessity of transitioning to a unified digital platform integrating predictive analytics functions and seamless interaction with various systems is substantiated. The proposed solution creates a foundation for developing digital twins of energy objects, reducing operational costs and commercial losses.

Introduction. Diesel generators sets are commonly used to power the refrigeration units of autonomous refrigerated cars. In order to increase energy efficiency of autonomous refrigerated cars it is proposed to switch from diesel fuel to liquefied natural gas (LNG), with transition from diesel fuel to LNG and introduction of cold recovery units from LNG regasification for additional cooling of cargo area in conjunction with the main refrigeration unit. This transition necessitates a comprehensive assessment of the potential for utilising the physical exergy available during the regasification process. The aim of the study is to determine the thermodynamic limits and justify the selection of operating parameters for LNG cold energy recovery in the auxiliary cooling circuit of the cargo compartment.

Materials and methods. The study employed numerical thermodynamic processes simulation of an open regasification cycle for LNG fuel. Energy and exergy analyses, along with the heat balance method, were utilised. Key indicators, including specific cooling capacity and second-law exergetic efficiency relative to the Carnot cycle, were calculated.

Results. The authors examined LNG cold recovery scheme based on an open cycle with a cryogenic pump. The results of the numerical simulation of the thermophysical regasification processes are presented. The dependencies of specific cooling capacity and exergetic efficiency on operating pressure were evaluated, and parameters ensuring the prevention of LNG boiling outside the recovery circuit were determined. It was established that pressure increase in the regasification line significantly enhances the thermodynamic efficiency of the system with negligible reduction in enthalpy potential.

Discussion and conclusion. Exergetic efficiency criteria for autonomous systems were formulated, enabling a transition from an enthalpy-based to an exergy-based assessment of LNG recovery potential. A rational range of operating pressures was identified, achieving a thermodynamic optimum for cold recovery. This operating mode is essential for ensuring the hydraulic stability of the fuel supply system, simplifying the refrigerated car design and unifying the fuel supply scheme during the transition to LNG usage.