Innovative braking system for high-speed 80-foot platform

The article discusses technical solutions for the creation of an effective design of a brake system for high-speed longwheelbase platforms intended for the transport of containers, as well as for the development of a fundamentally new brake equipment for the pneumatic, electro-pneumatic and mechanical parts of the brake system. Modular braking equipment for the pneumatic and electro-pneumatic parts of the high-speed platform braking system, compactly located under the platform frame, provides technical compatibility when controlling platform brakes as part of not only a high-speed freight train of permanent formation, but also in trains for other purposes, regardless of the location of the platform in the composition of the train. The performance of the braking equipment of each platform in motion and in the parking lot is monitored using pressure sensors and an electronic unit that processes the readings of the sensors and transmits information to the locomotive via one of the wire lines of the electro-pneumatic brake. The brake rigging used on the high-speed platform is arranged in the design of three-axle bogies and provides doublesided pressing on the wheels with typical composite brake pads, automatic regulation and maintenance of the standard clearances between brake pads and wheels. The proposed promising technical solutions make it possible to continuously diagnose the parameters of the brakes of each platform as part of a permanent train, display them on the locomotive monitor and transmit them to the dispatch centers of the Russian Railways infrastructure. Thanks to this, the braking effciency can be increased and the safety of train traffc can be ensured while increasing the permissible travel speeds. In the modern concept of digitalization of the infrastructure of Russian Railways, which provides for the creation in 2021–2025 (and in the future until 2030) of cars in which intelligent technologies should be applied, the braking system of a high-speed platform can be considered as the basis for creating a digitally controlled train — one of the key elements of the digital railway.

Methodic for evaluating the performance of a continuous welded track according to the criterion of compliance of the actual rail fastening temperature with the standardized value

Problem of safety evaluation of continuous welded track operation is considered. A comparative analysis of the current assessment methods is carried out and a method is proposed for identifying dangerous track sections according to the criterion of compliance of the actual rail fastening temperature with the standardized one. Under the actual fxing temperature in the article, the temperature of the rail is taken at which, as a result of its thermal expansion or contraction, a zero value of the longitudinal force is formed in it. A method is presented for calculating the actual temperature of rail fastening using the dependence of the natural frequency of rail vibrations on the applied longitudinal force, which was obtained by the computational method using the fnite element model of the track section created by the authors by means of modal calculations for various values of the longitudinal force applied to the rail. Its verifcation was carried out using experimental data obtained as a result of testing at a specialized stand. The method of tests carried out on the stand and section of the continuous track of the Ozerskaya branch of the Moscow Railway is described, which consists in determining the natural frequency of the first mode of rail vibration at different values of the longitudinal force, and in the case of field tests at different values of the rail temperature. The calculation of the actual temperature of rail fastening is given on the example of a section of a continuous-welded track of the Ozerskaya branch of the Moscow railway. It was found that the temperature of rail fastening on the investigated section corresponds to the normative for the given region.

Aspects of design and calculation of a railway track intended for dedicated passenger lines

The article considers issues of application of dedicated passenger lines for intertown and interregional transportation on the railways of the Russian Federation, which in the future will accelerate passenger traffic due to changes in transportation technology, increase the carrying and throughput capacity of railways, reduce construction costs and current maintenance, and optimize the need for infrastructure development. The structures of the track superstructure used for the transportation process at the present time were developed and implemented taking into account the mixed traffic — passenger and freight. Growth of axle loads in freight traffic, as well as the length of trains, presupposes the strengthening (weighting) of the standard structures of the railway track to possibly ensure the guaranteed safe passage of more than 1 billion gross tonnage. At the same time, exclusively for passenger traffic, the typical design of the railway track is redundant and can be optimized in terms of reducing the materials of the track superstructure with a simultaneous change in the configuration of repair schemes and current maintenance conditions. The article presents an assessing the possibility of using a “passenger” track structure on dedicated passenger lines for intertown and interregional transportation according to the criteria of the allowable margin of safety in the environment of fnite element analysis — the most progressive method for calculating structures undergoing complex loading. The article presents the results of calculations of the stress-strain state of a railway track of various confgurations, including promising lightweight versions with R50 rails and reinforced concrete sleepers with under sleeper pads. Based on the calculations performed, recommendations are given for the areas of application of the considered track confgurations from the point of view of permissible stresses in its elements.

Indicators of the force interaction of the track and rolling stock when a freight car runs on long irregularities, taking into account the action of longitudinal forces

Authors describe formation mechanism of long irregularities of the railway track and the importance of their elimination for the track facilities. Based on the results of freight train operation modeling on long irregularities in the traction mode, an analysis of the processes occurring during the motion of heavy trains along a track with such deviations was carried out, modeling was carried out on the basis of the “Universal Mechanism” software package. Based on the results of the calculation, interaction between the track and the rolling stock in the vertical plane was assessed in terms of the magnitude of the vertical force and coeffcients: dynamics, stability margin, Nadal, unloading (in percent) of axle springs of freight car springs. Article analizes the nature of the infuence of the irregularity slope on the decrease in the vertical force transmitted from the wheel to the rail and the change in the traction force on the dynamics of freight cars in the train and passing on long irregularities of the longitudinal profle through the indicators of the vertical force.

Operating conditions of container cars in railway trains of special formation

The article considers main technical characteristics, indicators of dynamic qualities and parameters of braking effciency of special railway rolling stock of container cars (container transporters) intended for the transportation of radioactive materials — spent nuclear fuel. In accordance with the current regulatory documents of JSC Russian Railways, it is currently allowed forming special trains exclusively from container transporters of any one type, which is associated with the peculiarities of the technology for handling and transporting spent nuclear fuel, which is within the competence of the state corporation Rosatom. However, this signifcantly increases the timing of the delivery of special trains due to the need to wait for the readiness of transporters, due to the non-simultaneous delivery of any one type of assembly kits with spent nuclear fuel. The practice of handling has shown that the transportation of some types of spent nuclear fuel can be carried out with a combination of the transport operation, which implies the combination of various types of container transporters in one echelon, but at the same time it is necessary to correct certain regulatory documents of Russian Railways. For this purpose, at the request of the Rosatom corporation, a necessary set of experimental works was carried out. Authors presented results of control running dynamic, stationary and running braking tests of container transporters of various types, following as part of the same echelon, on the infrastructure of the Test Loop of JSC “VNIIZHT”, including when running along the frst ring track and along various combinations of turnouts along a tangent line (main) and lateral directions. It has been experimentally proved that it is possible to operate container transporters of various types as part of the same echelon in compliance with the conditions for ensuring traffc safety in accordance with the standards of dynamic qualities and braking effciency. Based on the test results, a regulatory document of JSC Russian Railways was developed — the Regulation on the conditions for joint operation of special freight cars (transporters) as part of one echelon, approved by the order of JSC Russian Railways dated July 22, 2021 No. 1591/r. components. Interstate standard, put into effect as nat. standard of the Russian Federation by order of the Federal Agency for Technical Regulation and Metrology dated March 17, 2016 No. 162-st. Moscow, Standartinform Publ., 2016, 54 p. (in Russ.).

VNIIZHT Scientifc Journal celebrates 80th anniversary! Part I. The war years

Development of the railway industry depends on the work of many engineers and scientists who master the advanced technical and technological frontiers. The results of their work require experimental verification by specialists, technicians and engineers in the field. At the same time, in a systematic setting of the case, the conduct of experiments should be preceded by discussion and scientific discussion. A scientific and technical journal is intended to serve as an absentee format for such a discussion.In 2022, our magazine will celebrate its 80th anniversary. It was created by the order of the Political Administration of the People's Commissariat of Railways of the USSR in 1942, in the midst of the Great Patriotic War. The state entrusted our journal with a very important mission — concentration and dissemination of experience in the restoration of damaged communication lines and development of new technologies for military freight and passenger railway transportation. This extreme practical orientation and an urgent need for empirical knowledge was reflected in the choice of the original name of the journal — “Railways engineering”.Since the creation of the journal, the editorial staff have striven to fulfll the mission entrusted to it and to maintain a high level of domestic railway science. Several stages can be distinguished in the eighty-year history of the VNIIZHT scientifc journal.This article presents an analysis of the frst stage — the stage of the war years.

Features of assessing the condition and behavior of low-water bridges

The article describes features of operation and monitoring of low-water bridges, which are found on highways of regional, intermunicipal and local importance. Vibrations of the bridge span are considered in detail, taking into account its interaction with other structural elements and the environment. As a characteristic, the change of which takes into account the change in the state of the bridge structure, it is proposed to use the frequency of natural vibrations. To simulate the dynamic effects of transport and the dynamic behavior of individual elements and the entire structure as a whole, it is proposed to use viscoelastic elements of the Kelvin–Voigt type. When solving the problem, an approach has been implemented that makes it possible to take into account the anisotropic properties of the superstructure associated with various reinforcement along and across the roadway of the bridge, and to present the design scheme of the span not in the form of a beam supported at the edges with the help of hinges or viscoelastic dampers, but in the form of a plate, which can have different fxing conditions along the entire contour. The use of the proposed model and approach will make it possible to obtain the necessary data on the state of low-water bridges, for which there is often no possibility of visual inspection or instrumental inspection from the lower side of the bearing part of the superstructure. By the values of the frequency of natural vibrations, it is possible to estimate the water level above the low-water period and predict food situations, during which the roadway of the low-water bridge may be fooded.

Prospective approaches to predictive modeling of degradation processes of track superstructure elements and its application in creating digital twins

It’s impossible to use digital technologies without using the amount of information coming from various systems designed to manage the transportation process and plan its work, taking into account modern economic requirements and resource constraints. Digital twins are currently the most promising tool for solving the problems of managing technically rich multi-level assets, which include railway transport. The track facilities are one of the most expensive assets, and the issues of organizing the management of the maintenance of the railway track are very acute, since they are directly related to the safety of train traffic, therefore, the development of a digital twin of the railway track is a priority task for track science. A digital twin of a railway track should contain elements of BigData technology in the form of arrays of diagnostic data coming online from mobile and stationary diagnostic tools, an array of passport data about the track device, as well as a set of models that can convert this data into matrices “state — action”, suitable for making organizational and technical decisions on the management of the track complex, starting from the level of linear enterprises and ending with network tasks. The article presents models that can be taken as a foundation for building digital twins of a railway track. The results of verification and approbation of the proposed models in the “Neyroekspert-Put’” software package are also presented.

Personnel training in digital logistics and supply chain management

The system of training personnel in the field of logistics and supply chain management is currently experiencing an increasing impact of digitalization. The object of the research is the current state of this system in Russia.It is claimed that digitalization will change the requirements for personnel involved in logistics, so the appearance of a new position — administrator of digital logistics and supply chain management (administrator of material flows digitalization) — seems logical.To assess the consequences of digitalization of the personnel training system, the methodology of the theory of inventive problem solving was used. In accordance with this methodology, the subjects of the Russian education system are distinguished that perform the following functions: “calculator” (Ministry of Education and Science, etc.), “source of energy” (institutions of preschool, secondary and additional education), “engine” (institutions of secondary specialized and higher education), “transmission” (organizations for the employment of specialists in the field of logistics), “working body” (enterprises and organizations in which logistics specialists work).Quantitative dependencies and models are proposed for assessing the effectiveness of the Russian system of personnel training in the field of logistics and supply chain management. The performance of each element of the personnel training system has been determined. It is stated that this system does not fully meet the needs of the market and the expectations of students, and also indirectly inhibits the transition from competition between individual manufacturers to competition in supply chains, thereby holding back the development of the Russian economy.

Increasing the energy efficiency of auxiliary machines of AC electric locomotive

Currently, an asynchronous variable frequency drive based on semiconductor converters is widely used due to the relative simplicity and reliability of the design. The use of digital microprocessor systems ensures high accuracy and flexibility of drive control. On the domestic rolling stock, the widespread introduction of asynchronous motors began to replace DC traction motors with sequential excitation. In particular, scalar-controlled asynchronous motors are used on serially produced 2TE25A diesel locomotives and EP20 electric locomotives. The auxiliary asynchronous machines of these locomotives are controlled by the vector control method. The use of a new type of engine on the rolling stock makes it possible to achieve a significant increase in the quality of consumed energy and reduce the consumption of electricity for traction of trains. Ensuring the energy efficiency of the drive in a wide range of loads requires further research. In this regard, the issue of saving energy resources becomes very urgent. The article proposes a vector control scheme for asynchronous motors of auxiliary machines of an electric locomotive, which implements an extreme method of control according to the criterion of minimizing the consumed current. The analysis of the engine operation is carried out based on its mathematical model in a rotating coordinate system d — q, which is implemented in the MatLab/Simulink software package. As a result of simulation modeling, it was found that the extreme control system with a variable step allows for each fixed value of the electromagnetic moment of the motor in the minimum time to find the optimal (extreme) value of the magnetic flux of the motor rotor, which corresponds to the minimum value of the stator current. The developed model of the motor with vector control is supplemented with an extreme regulator device, which allows achieving the best energy performance of the motor and reducing electrical losses in all operating modes with a minimum search time. The presented research results can be used in the development of energy-saving control systems for an asynchronous motor.