The article presents the results of a study on the tightening forces of screws in ZhBR-65Sh fastenings for three groups of screws with different conditions of the threaded surface, using a constant standard tightening torque of 250 N·m. Strain gauges installed on the clip were used for the experimental determination of the actual clamping force in the thread. The arrangement of the strain gauges was chosen based on a preliminary study of the stressstrain state of the ZhBR-65 fastening clip. The most characteristic deformation zones of the elastic clip are the technological bends in the end and side sections. The modeling also showed that the share of the elastic clip's clamping force acting on the rail base is 40.2% of the tightening force of the track screw.

The results of the study show that the tightening force of track screws is a random variable distributed according to a normal law. Screws with signs of corrosion and thread contamination, under increased rail clamping force requirements for regions with annual temperature fluctuations greater than 110°C, are unable to provide the necessary clamping in more than half of the cases. Cleaning the threads significantly increases the likelihood of achieving the required force; however, only the use of lubricated screws almost completely guarantees compliance with rail clamping standards. Such a wide range of tightening forces does not allow the anti-creep and elastic properties of modern intermediate rail fastenings to be effectively realized.

One of the strategic directions of development of railway transport is increasing axle load, speeds and intensity of train traffic. Increasing these parameters is complicated by "barrier" places, including approaches to bridge crossings.

To ensure reliability in these areas, the study was conducted based on data obtained from track measuring cars on the West Siberian Railway, as well as on the analysis of scientific and technical literature. A hypothesis was put forward about the presence of four zones, where the approach to the bridge crossing is conditionally divided into sections in which a difference in stiffness is observed. It was revealed that stiffness jumps occur in specific areas and in the same places.

In this regard, a system of zones "span structure – abutment – roadbed" is proposed, which does not depend on operating conditions. A qualitative coincidence of the author's data on the West Siberian Railway with domestic and foreign sources is established.

The work reveals a contradiction between the existing regulatory requirements and actual data on the length of sections of the transition track of variable stiffness, which emphasizes the need for an individual approach to the design of such sections taking into account various operational factors.

This work is devoted to the consideration of the possibility of creating a material with improved characteristics, namely reduced weight and thermal conductivity, using a filler in the form of hollow ceramic spheres to reduce the stress-strain state of the foundation of soil engineering objects and the effect of temperatures on soil stability. The constituent elements of the geopolymer were studied by electron microscopy methods, their composition and some properties were determined, as well as thermal conductivity, density and compressive strength of geopolymer samples. As a result of the studies, it was shown that adding microspheres to the geopolymer improves its thermal conductivity properties and lightens the design of the roadbed.

The technical and economic parameters of flat cars with a loading length of 60 feet are examined, taking into account their pricing and freight train parameters. An analysis of serial flat cars is performed based on the parameter of the car length along the coupling axes and the impact of this parameter on the current tariff coefficient during transportation, as well as the parameters of a container train formed from flat cars with different lengths along the coupling axes. Technical solutions allowing to reduce the length of a flat car along the coupling axes of automatic couplers without reducing the loading length are considered. Preliminary technical and economic parameters of a platform car with a loading length of 60 feet and a length along the coupling axes of automatic couplers have been determined, at which the length of a container train is guaranteed to increase to 71 conventional cars, which ensures the transportation of 153 ... 156 TEU units (20-foot container volumes) and increases the performance of such a train by 2...4 %. The proposed technical solutions can be applied in the development of new and modernized designs of platform cars.

The article is devoted to the assessment of the indicators of a multi-phase system of technical maintenance (TM) and current uncoupled repair (RIR) of freight cars at technical maintenance points (TMP). The relevance of the study is due to the risks of failures of technical elements of cars in the conditions of mass servicing of rolling stock flows. To optimize the processes, a methodology of mass service theory (MST) with decomposition into three successive phases is proposed.

The TM model as a three-phase MST includes three phases, each of which considers the servicing process as three simple MST with its own parameters. Key performance indicators are calculated based on the specified parameters.

The modeling results allow us to identify "bottlenecks" at a specific phase, which helps to increase the efficiency of servicing freight cars located in TM by 18 %. The proposed optimization methods confirm the possibility of increasing throughput by 15–20 %. The practical significance of the work lies in recommendations for the modernization of TM, and further research will focus on the simulation modeling of the processes of a multi-phase technical maintenance system.

The paper considers technical solutions obtained by step-by-step optimization of enclosing structures of thermos wagons. The main goal of optimization is to reduce material consumption without increasing the overall heat transfer coefficient.

A key aspect of the research is the developed step-by-step optimization algorithm based on a combination of analytical calculations and the finite element method. This made it possible to evaluate the thermal engineering properties of the structure, eliminating thermal insulation in areas that do not affect the overall coefficient of thermal conductivity of the thermos car.

The results of the work are of practical importance for wagon-building enterprises, as they make it possible to reduce the cost of manufacturing thermos wagons, reduce the labor intensity of production and improve their technical and economic performance.

The article discusses the development prospects of the Eastern Polygon, which indicate the need to increase the service life of the equipment of electric locomotives in operation. It was revealed that the greatest number of failures occurs in the traction electric motor, namely, in its collector-brush device due to the occurrence of an electric arc transfer. The reasons for its occurrence are considered. A method for determining the degree of sparking of the traction electric motor has been developed based on a comparison of the analytically calculated values of reactive EMF and interlamellar voltage by the intelligent unit with their permissible values established empirically. The article presents an algorithm for the operation of the proposed software and hardware complex for monitoring the traction motor of an electric locomotive during operation.

The design of the freight bogies used in operation does not allow the traffic of freight trains to be implemented within the schedule of passenger trains. For this purpose, a three-axle bogie has been developed, which allows increasing the design speed of a freight wagon up to 140 km/h. The characteristics of the wheelset elastic linkage with the bogie frame and of the elastic side bearings have an effect on the wagon dynamic qualities.

Research was conducted into the dynamic qualities and impact on the track (experimental trips) of a long-base flat wagon with an increased design speed with two three-axle bogies equipped by experimental buffer plate suspension rod units and elastic side bearings between the bogie and the flat wagon frame. Based on the conducted research, rational technical solutions for the spindle axle box unit the buffer plate suspension rod unit and elastic side bearing were selected.

The process of creating and researching a model of a traction electric motor of an electric locomotive in the environment of computer circuit modeling is considered. The model takes into account the magnetization curve of a real motor and the nonlinear inductance of the excitation winding, which makes it possible to more adequately reflect electromagnetic processes. The inductance of the excitation winding is determined based on the slope of the magnetization curve and the parameters of the winding poles. The model also allows it to be used in circuit modeling of transients in the electric power circuit of an electric locomotive. Two traction motor models were compared: one took into account the magnetization curve, and the other implemented a linear model in which the inductance of the excitation winding is constant. The parameters of the traction engine from operation were also compared with the calculation results of the developed model. The results of the comparison showed that the use of a nonlinear model makes it possible to calculate the traction motor current more accurately.

The paper presents the main ideas of a method for estimating the amount of air leakage from a diesel cylinder during compression, based on analyzing the rate of change of the in-cylinder pressure. A new diagnostic parameter is proposed, calculated using continuous signal measurements during the transition of an unloaded diesel engine from one speed mode to another. Unlike known methods using in-cylinder pressure, determining the proposed parameter does not require shutting off the fuel supply in the cylinders. In addition, the parameter is not sensitive to possible changes in the degree of compression across the cylinders, the air density at the cylinder inlet, and other factors that complicate the estimation of cylinder hydraulic tightness based on the pressure at the end of compression. The main results of the study were obtained during mathematical modeling and confirmed experimentally.

Most mechanical joints in railway transport use interference fits to connect the axle and wheel. The wheelset is a is a joint with an interference fit of the wheel with the axle and can be subjected to all kinds of loads. Due to the high stress concentration, the processes of fatigue and fretting corrosion of the axle can lead to the destruction of the joint, therefore, it is necessary to assess the amount of sliding affecting the joint strength of the wheel and the axle as a whole, to determine the ability of the press joints to resist friction and withstand loads. Using the Lame equation and the numerical method by means of the Ansys complex, the distribution of contact pressure, deformations and stresses of the wheel and axle are analyzed, and sliding in the press joint is estimated. The novelty of the study lies in comparing a model that maximally simulates the press joint of a wheelset with a shaft – sleeve joint, the parameters of which are theoretically verified. The results of the study provide an understanding of the processes occurring in the press joint that cannot be physically controlled, in particular, the prevalence of sliding zones, as well as adhesion, affecting the bearing capacity of the joint, which is directly related to traffic safety.

The results of comparative traction-energy tests of a 3ES5K locomotive with axial traction control, equipped with a friction activation device (FAD), with a locomotive of the 3ES5K series with axial control, not equipped with a FAD friction activation device, are presented.

The locomotives were tested at the head of freight trains weighing 7,078 tons and 7,101 tons on the Krasnoyarsk – Vostochny – Ilanskaya station section of the East Siberian Traction Directorate. A comparative assessment of the traction and coupling properties of the 3ES5K series locomotive No. 1147, equipped with a locomotive friction activation device, and the 3ES5K series locomotive No. 1271, not equipped with a FAD, was carried out during the analysis of the parameters recorded by traction and energy laboratories. The parameters were recorded when the locomotives were moving along the sections of the limiting grades of the tracks. Based on the results of processing data from control runs of the tested locomotives, it was found that the traction and coupling properties of locomotives during tests under identical conditions were higher for experimental 3ES5K electric locomotive No. 1147 equipped with a FAD, than for control electric locomotive No. 1271 not equipped with a FAD.

Based on the test results, conclusions were drawn about the movement of trains along the sections of the route and the limiting ascents. A comparison of the obtained experimental data is carried out.

Braking equipment is the main provision of an integrated active safety system. Despite the abundance of work in the field of research on braking devices, this unit remains with numerous problems that can affect the specified operational properties of rolling stock. To assess the factors influencing the braking torque curve, a mathematical model was developed that takes into account the design and technological parameters of the caliper mechanism, as one of the main elements of the braking device design. The system of equations of forces and moments allowed us to determine the dependencies for calculating linear and angular displacements of the shoe, taking into account its inertial characteristics, stiffness and damping parameters. To calculate the inertial load of the brake pad SHOE, as the main characteristic of the shoe displacement of the pad relative to the calculated position of the center of pressure in the tangential and radial directions, the total values of acceleration fluctuations in the longitudinal and transverse directions of the shoe for its four edges were determined. According to the diagram obtained, it can be argued that the brake pad at the beginning of braking is displaced in the direction of rotation of the disc and the periphery of the brake disc, which leads to a short-term increase in braking torque.

The article extends the authors' previous research, focusing on optimizing container flow distribution in a railway terminal network while accounting for the routing of consolidated container trains. An existing linear programming model is modified by incorporating economies of scale in train formation, transforming it into a mixed integer programming problem and significantly increasing computational complexity. To solve this NP-hard problem, a practical iterative algorithm is proposed as a compromise between accuracy and feasibility. The model enables the determination of optimal routes, terminal specialization, and transportation volumes, as well as scenario analysis to improve the efficiency of the container transportation system.

This article examines methodological approaches to assessing the performance of large transportation holdings, using rail transport as an example, for the implementation of intelligent management technologies. A conceptual analysis of the system for organizing analytical accounting of the performance of the holding company as a whole is provided and its structural divisions within a unified organizational and technological system for transportation process management, taking into account horizontal and vertical relationships. The diversity of technological relationships within the hierarchical organizational and technological structure of a corporation is presented, including the specifics of activities, relationships, and the degree of dependence of related structures.

This article examines specific methods for aggregating and comprehensively accounting for rail transport performance indicators to achieve economic efficiency. Methods for aggregating the performance indicators of the railway holding's structural divisions are presented, taking into account their presentation in the accounting policy, the types of indicator dependencies by management levels and activities, and the correlations between them. The paper presents the potential for using holding performance indicators in an intelligent transportation management system.

A transformation scheme for transportation process agents is proposed for implementing a development trajectory using integrated performance indicators for intelligent transportation management.

The presented methodological approaches to analyzing technological processes in transport and logistics systems can also be applied to related industries and holdings that represent complex organizational and technological structures.

The paper proposes a method for modeling the optimal inter-train interval under conditions of random train delays, based on statistical data collected from the Trans-Siberian Railway. The relevance of the study is due to the need to take into account random deviations when developing a freight train schedule with an increased degree of reliability in conditions of decreasing inter-train intervals using interval control systems. Delays were modeled using the Chi-square, Gamma, Erlang and Weibull distributions to determine the minimum intertrain interval that ensures schedule stability without accumulating additional delays. Recommendations are proposed for optimizing the technical speed of movement and introducing buffer time to prevent possible disruptions to the schedule.

The presented article is devoted to the study and assessment of the railway polygon capacity in the context of the introduction of a forced train schedule, characterized by the integration of connected trains into the traffic system. The authors conduct a comparative analysis of the methods for determining the capacity, based on a comparison of the results obtained by applying an analytical formula used in practice and the results generated by simulation modeling. The paper concludes that it is advisable and necessary to use a specialized software package (IMETRA system) to build realistic models of railway track operation that adequately reflect the complex interactions of the elements of the transport system. The article presents the results of experimental studies carried out on the basis of a simulation model developed at the Ural State Transport University, aimed at analyzing the impact of a forced train schedule on delays for various categories of trains. The results obtained make it possible to evaluate the effectiveness of the forced schedule implementation and identify potential bottlenecks in the functioning of the railway polygon.

The article examines the problem of assessing the readiness of transport and logistics entities for the implementation of digital platforms as a key direction of the industry’s digital transformation. Based on a systematic analysis of Russian scientific and regulatory literature, the necessity of moving from fragmented indicators to comprehensive index-based methodologies that ensure comparability and universality of results is substantiated. A methodological approach is proposed that includes the formation of a system of partial indices across four blocks: strategic, human resources, technological, and organizational readiness. For each block, groups of indicators have been developed that make it possible to quantitatively assess the state of digital maturity of entities. The procedure of data normalization, calculation of partial indices, and their aggregation into an integral index of digital readiness is presented. An interpretation scale of results has been developed, allowing the classification of enterprises by maturity levels (absence, low, medium, high). The scientific novelty of the study lies in adapting the index method to the specifics of the transport and logistics sector and in developing a unified system of digital maturity indicators. The practical significance lies in the possibility of using the methodology by government authorities, transport enterprises, and logistics operators to substantiate digital strategies and investment decisions.

A computational model of a modified radial bearing design is proposed. This model considers nonlinear factors describing the movement of a micropolar lubricant within the bearing clearance with a non-standard bearing profile adapted to friction conditions. Unlike previous approaches, the developed model makes it possible to more accurately calculate the distribution of pressure and velocity in a layer of micropolar lubricant when determining the load capacity and the value of friction coefficient. The novelty of the study lies in the simultaneous consideration of nonlinear factors and rheological properties of the micropolar lubricant of a modified radial bearing with a support profile adapted to friction conditions, as well as in the comprehensive verification of the model using experimental data, ensuring its practical significance.

The creation of economical and durable coatings based on fluorine-containing compounds is one of the most important tasks in modern science. However, the high cost of fluoroplastic, which is a key component, has led to a constant search for ways to reduce the cost of producing these coatings without compromising their performance. The key idea is to create a multi-layer coating where each layer has a specific function. The matrix binder is a three-component system consisting of rubber, powdered copper, and molybdenum disulfide. The adhesion strength of the composite coating applied to a steel substrate was studied by peeling the samples at an angle of 180 degrees.

The test results of various rope lubricants are presented to assess their effect on the wear resistance of steel rope. The study of tribotechnical properties of lubricants was carried out in accordance with GOST 9490-75 “Liquid and plastic lubricants. A method for determining tribological characteristics on a four-ball machine”, as well as according to the experimental methodology proposed in the work. The effect of the lubricant on the wear resistance of the steel rope was estimated by the number of rope bending cycles until complete destruction in accordance with GOST 2387-80 “Steel ropes. The endurance test method.” It has been established that the most correct and reliable method for assessing the effect of a lubricant on the wear resistance of a steel rope is to test full-scale rope samples on a running machine.

The paper presents a version of the structure of lubricant for open heavy-loaded friction units. A planning matrix of a full-factor experiment is also presented, taking into account combinations of component concentrations. Considering the specific nature of open, dynamically loaded friction pairs, it has been established that the use of a solid-plastic lubricant is most effective for these tribosystems. According to the proposed approach, lubricant development should focus on improving the structure and secondary properties of new lubricant compositions. Since the structure of a lubricant is primarily determined by the structure and complex of mechanical, chemical, and thermal properties of the three-dimensional framework formed by the thickener within the lubricant layer and the two-dimensional porous supporting layer associated with the framework on the friction surface.

Recently, rubber crumb, 1–3 mm in size, obtained from processing rubber products in horizontal shredders, is currently widely used as a secondary raw material. In this case, the material interacts with only two or three cutting elements, which necessitates the use of multistage shredding. The design of a vertical shredder with a stator having wedge-shaped grooves, with a vertical rotor, with a variable arrangement of adjusting and cutting knives with different numbers of teeth is proposed. An adequate regression equation has been obtained for the dependence of the maximum amount of crumbs in the range of 1-3 mm on the main factors ‒ the thickness of the adjusting knife and the increase in the number of cutting knives. Studies have shown that to obtain 70–75 % of a 1–3 mm rubber crumb, it is advisable to use a rotor with 7 cutting knives and 130 rpm, whereas with a 2 mm thick adjusting knife, a 3 mm cuboid fraction of the finished product prevails, and with a 10 mm thickness, 1 mm ragged particles predominate.

Some types of multi-component rotating parts having an explicit or implicit asymmetry are considered, and an improved disk hopper feeding and orienting device with radial pockets, a copier, and a regulated ring orientator is proposed. This device accumulates products, orients them, and divides the mass of products into individual pieces, which are then fed to the actuators of automatic machines with the required productivity. The main stages of designing an improved device are described, in the process of which feeding of asymmetric multi-component products differing in shape and size, consisting of various materials and coatings, will be implemented, with the possibility of quick re-adjustment of the device depending on the shape and size of the product, and stable operation will be ensured when orienting multi-component products in order to increase its productivity.

In the severe conditions of the Far North, the effect of polymers aging on their properties is important due to the long-term impact of various environmental factors leading to polymer degradation. In this work, friction and wear tests were carried out using a scheme simulating a sealing unit, a two-layer composite “rubber - ultra-high molecular weight polyethylene” under various loads, sliding speeds and temperatures. The effect of climatic and thermal aging on the frictional properties and wear resistance of the two-layer composite was estimated. It was found that the friction coefficient depends on the sliding speed, load and external temperature. Aging of the material leads to a decrease in the friction coefficient. The wear resistance of the material increases by 25 % in the second month of aging and does not change over the next four. With accelerated aging tests, wear decreases by 15 %. It can be concluded that the material can be used in friction units for a period limited to six months of climatic aging, and in friction units protected from solar radiation, it can be used without time restrictions.