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Comparative bench tests of acoustic emission occurring during the interaction of the brake pad with a brake disc for the brake unit with a stationary brake pad and a brake unit with a floating brake pad are carried out. The floating brake pad, depending on the braking conditions, occupies an optimum position on the surface of the brake disc, while making movements of an oscillating nature around the turning axis that does not pass through its center of mass and parallel to the axis of rotation of the brake disc. The frequency range is determined in which there are noticeable differences in the acoustic emission of a brake unit with a floating brake pad and a stationary brake pad. The theory of fuzzy sets is used to analyze the acoustic emission perceived by the human hearing organs, which accompanies the interaction of the surfaces of a friction pair in the investigated frequency region. The results of a comparative analysis of the noise characteristics of the brake blocks under investigation are discussed. The spectra of the acoustic emission power are compared according to the obtained base of the expert evaluation of the noise power perceived by man.

To increase the speed of the cargo delivery, freight wagons are being developed, intended for the design speed of 140 km/h. One of the important parts of a freight wagon is the bogie, the design of which determines the wagon dynamic behaviour. The bogie of such wagons uses a frame of a rigid design, which is susceptible to antisymmetric loads. The analysis of standards has shown that the strength test during designing a rigid bogie frame under the impact of maximum antisymmetric forces that may occur in operation when a wheel derails is not required, which can lead to a residual antysymmetric deformation of the bogie frame. Theoretical research is performed to estimate the impact of the residual antisymmetric deformation on traffic safety using the wheelset safety factor against derailment. The research results have shown that the bogie frame residual deformation leads to a load redistribution on the wheelset axle journal, which, in terms of the impact on the wheelset safety factor against derailment, is similar to the wagon rolling motion. The wagon rolling motion affects the reduction of the wheelset safety factor against derailment to a greater extent than oscillations during pitching and bouncing. Thus, the permission to operate wagons with the antisymmetric residual deformation of the bogie frame without its non-destructive testing can lead to traffic safety violation. In order to ensure the traffic safety of wagons with bogies having rigid frames and reduce economic losses at the design stage, bogies strength depending on the action of antisymmetric forces should be estimated.

The work relates to the application of a new method of noncontact RFID monitoring of the condition of insulators for overhead power lines, including signaling, centralizing, blocking, and longitudinal power supply lines . A significant number of accidents occur due to the breakdown of insulators and imperfection of control methods. It is proposed to use a non-contact RFID control system for overhead power line insulators, which consists of a reader with a transceiver and an antenna, standard insulators with RFID indicators and special software. The aim of the research is the influence of climatic factors on the components and assembly structures of pin insulators with RFID indicators and the operation of the RFID control system in general. The selected study samples are a radio frequency tag, an aluminum-coated plastic cap with an integrated tag, and a pin-shaped porcelain insulator with an RFID indicator in the assembly. The climatic tests were carried out in the testing center of technical means of railway transport of the Ural State University of Railway Transport (IC TSZHT USUPS). Temperature changes were simulated from -60 to +50 ° С with air humidity up to 93%. The results on the adhesive properties and electrical conductivity of a conductive coating on a polyethylene surface and the stability of the functioning of RFID tags are presented and analyzed. Suggestions for improving the components and assembly design are given. Firstly, to use a screw thread on the top of the pin instead of a special knurling, which will reduce mechanical stress during installation of the structure of individual components and will reduce the error in the installation dimensions to improve the reception and transmission of signals between the reader and the tag. Secondly, sandblasting of the surface of the polyethylene cap can improve the adhesion of the surface to the conductive coating, which will increase the electrical conductivity of the structure. The result of this work proves that the developed RFID control system of insulators functions in the climatic conditions specified by GOST, which allows to recommend its implementation in the lines ts use in lines of devices with a voltage of 6-10 and 35 kV.

The article deals with the possibility of energy utilization of exhaust gases of diesel-generator sets of locomotives during load tests. The calculation of the amount of heat carried out during tests with exhaust gases. Possible variants of heat utilization with the use of various heat exchangers are considered.

The issue of optimizing the use of lubricants to reduce the in-intensity wear of the wheels of traction rolling stock is considered in the work. The purpose of the work and the test objects are defined. The types of tests, their procedure, short description of tests, and compliance with the technical assignment and technical requirements are presented. Design work was carried out on the development of solid antifriction elements for lubricating the ridges of locomotive wheel pairs (hereinafter referred to as TAEL rods). Bench tests were carried out on a universal friction machine 2168 UMT «Unitrib», which models the contact interaction of the wheel with the rail when applying solid lubricant to the wheel ridge. The linear wear rate of the lubricating element and the friction moment were determined. Explutation tests were carried out on the basis of traction rolling stock of the series VL80, 2TE25KM, ChME3. Such indicators as average intensity of development of cores of TAEL and lubricant cores and average intensity of wear of crests of wheels were defined. The results of laboratory bench-out and operational tests of TAEL rods were obtained in accordance with the order of admission of lubricating materials for wheel-rail contact for use in locomotive combs operated on the railways of the Russian Federation. Operational tests of traction rolling stock were carried out at the landfills of the North Caucasus, South-Eastern and Volga Railways. During the performance test period, the following indicators were monitored: assessment of the impact of TAEL on the wear of co-forest steam ridges, assessment of the actual resource of TAEL production, assessment of the functional capabilities of TAEL rods. According to the test results, the developed TAEL rods received permission to use Russian Railways for the infrastructure. At the same time, the wear rate of the ridges of the wheel pairs of locomotives equipped with TAEL in comparison with the standard rods decreased to 50 %.

In this article, the problem of assessing the stability of a continuous welded rail track during its thermal elongation is considered. The article considers the method of determining a stress-strain state of continuous welded rails proposed by specialists of JSC “VNIKTI”, which is based on the use of the dependence of natural frequencies of rail vibrations on the applied longitudinal force. Such a dependence can be obtained with the help of the calculation method using a finite element model of a track section. The reliability of such a dependence can be assessed by comparing the results obtained using the calculation method with the actual values of natural frequencies of rail vibrations, depending on the longitudinal tensile and compression force applied to a full-scale facility. The track panel is chosen as such a facility. In order to obtain the actual dependence of natural frequencies of rail vibrations on the applied longitudinal force, a specialized test bench is developed. The development of the test bench included designing the test bench elements and creating finite element models of main load-bearing elements of the test bench - a stop, support and traction, as well as their subsequent strength calculation to confirm the operability of the selected design under necessary loading conditions. The strength is assessed using the safety factor for the yield strength. Calculations using the finite element method have shown that the test bench design has sufficient strength. The developed test bench will allow performing tests for the purpose of the verification obtained using the calculation method of the dependence of rail vibration frequencies on the longitudinal tension and compression force applied to it, as well as for testing the proposed method to assess the rail longitudinal force during its thermal expansion.

The authors propose a model of justification of the duration of the operation liner-tamping-straightening and construction machinery. Using this model, we can evaluate the efficiency and reliability of machines on any object. This allows you to most reliably predict the timing of production of certain types of works and their cost at the design stage. The article presents the indicators of full-scale tests and the estimation of reliability of manufacturing operations. One of the main factors of reliability of work of construction machines is the utilization of their time. All normative documents are obsolete data on the utilization of machines during the working time, which need updating, as the machines are constantly improving. To assess the reliability of working machines, the authors developed a database of the results of field tests liner-tamping-straightening machines, cranes, excavators, bulldozers, pipe layers, drilling rigs and dredges. To prove the validity of database values according to the results of full-scale tests were carried out two stages of verification: logical and mathematical. After sampling in accordance with GOST R 8.736-2011 was verified that it belongs to the law of normal distribution using the criterion of Pearson agreement. It was further calculated the reliability and risk of the planned volume of work in scheduled period of time. When it was considered the utilization ratio of machines time and the risk of deviation from the mean. The proposed approach to the assessment of duration of liner-tamping-straightening and construction machinery can be extended to any type of equipment and will allow to obtain numerical values for evaluating the reliability of production work in the scheduled time, which is very important in the construction, repair and maintenance.

The article outlines modern approaches to determining the maximum permissible continuous current of current collectors when stopping and in motion. The features of techniques that reliably take into account operational factors when conducting tests in laboratory conditions are considered. A mathematical model is given for studying the distribution of current load in emergency mode of breaking a current-carrying shunt.