Analytical support to organization system of children transportation in long-distance trains

In modern conditions for passenger complex of Russian Railways, important tasks include improvement of transportation quality, maintenance of stable positions in a competitive environment and increasing demand. To address these issues, a customer-oriented approach is applied based on the segmentation of transport market in relation to certain groups of passengers. Performance of children's transportation is of particular relevance and social significance. Railways are charged with a huge range of work, including sale of travel documents, preparation and equipping of passenger cars, provision of food during the trip, instructing workers, ensuring security during the embarkation/disembarkation of passengers, etc. Children can travel as individually with accompanying persons and as part of organized groups. Processes of planning, organizing, monitoring the transportation of this age category of passengers are associated with the analysis of a large amount of reference and regulatory and reporting documentation. On the basis of the ACS “Express-3”, a program-analytical complex “Children's transportation” was developed and implemented, which allows to receive data at the regional and network levels in the operational (train number, day) and statistical (period of dates, month) modes. This information technology provides analytical support for key transportation management functions — planning, control, analysis. Planning of transportation of organized children's groups is carried out on the basis of a study of the dynamics of data on the number of applications received and travel documents issued, determining the routes of trains, periods of the highest intensity of passenger traffic, obtaining information about the stations of embarkation and disembarkation. To perform the functions of monitoring the embarkation and disembarkation at the destination station of groups of children, the employees involved receive information on the train number, car number, date and time of arrival, number of children in the group using the Children's Transportation software. For the analysis of transportation of children's age categories, a functional has been developed that ensures the construction of aggregated reporting based on trains data that completed the trip. Users receive reporting information in table form, including “strict” (designed according to the approved layout) and “flexible” forms (construction is performed according to specified parameters). Software and analytical complex is designed for managers and specialists of the passenger unit of the JSC “Russian Railways”, has a modular principle of increasing functionality and provides a solution to current problems in the system of organizing children's transport service.

Perspective constructions of bridge overpasses on transport main lines

When designing bridges on motorways and railways, conventional beam or trussed design schemes of structures made of steel or reinforced concrete are used, but at present there is a significant increase in the speeds of motion of individual vehicles, axial loads and total train weight increase, and temporary intervals between trains.

These factors lead to a significant increase in dynamic effects and necessitate the use of non-classical design schemes for artificial structures of transport infrastructure. In this study, it is proposed to take a threespan arch bridge with suspended central span structure as the basis for unified bridge overpass. Such an arrangement will allow changing the design length of the central span in a fairly wide range, reducing the total number of supports with an increase in the total length of  the bridge overpass, and using a similar design as a double-track railroad, two- or four-lane motorway bridge. Calculations carried out and the results obtained for calculating displacements, internal forces and stresses in the units and elements of the proposed bridge overpass design allow concluding about the allowable limit values of the values found, sufficiently uniform load of all its main elements, the absence of strongly marked large-scale stress concentrators. Proposed design allows setting different sizes of spans during the design, reducing the number or even avoiding the installation of channel supports, adapting this structure for the passage of both rail and road transport. Design of the bridge, mathematical model of which is described in detail in the article, can be manufactured at the factory, and then delivered to the installation site and mounted there, which significantly reduces the final construction cost and makes it a profitable solution, for example, for arranging railway interchanges at different levels.

Ensuring electrical safety of power supply systems of electrified AC railways for  highspeed lines

High-speed railways are fast-growing and promising type of traffic. In Russia  development of high-speed railway service is associated with the solution of a number of problems, including infrastructure. Authors propose to use earth connection of the railway catenary with the help of an artificial earthing switch on currently designed high-speed line Moscow — Kazan for 2×25 kV power supply system.

Taking into account requirements for electrical safety conditions for maintenance of the track and earthed catenary supports, paper justifies method for calculating allowable voltages of rail — earth points and supports of catenary. Methods takes into account structural features of ballastless track superstructure used for high-speed lines. It is estimated that the voltages admissible under the electrical safety conditions are random in nature and distributed logarithmically normal. When calculating probability of safe operation, one should take into account random nature of both permissible stresses and those actually occurring on the track.

It is estimated that the probability of safe operation in traction networks of sections with ballastless track superstructure does not exceed a similar value in electrified sections with the conventional structure of a ballast prism. Feasibility of using a 2×25 kV earth system using an artificial earth connection is confirmed, recommendations n its use are given. Authors substantiate allowable values of the rail — earth voltage and catenary supports, which practically exclude the occurrence of hazardous situations for personnel maintaining the track in sections with ballastless track superstructure.

Methodical approaches to the economic assessment of costs in the operation of cars with axial load of 27 tons at the section Kachkanar — Smychka

The most important direction of increasing the efficiency of rail transportation is to increase the load-carrying capacity of freight cars as a result of an increase in axial loads. New car 12-9548-01 with improved technical characteristics has an axial load of 27 tons. The article describes method of calculating the coefficientreflecting the change in the impact of cars with an axial load of 27 tons on the roadbed during transportation in estimated cars compared to transportation in equivalent cars. Algorithms for calculating changes in the cost of fuel and energy costs for train traction and maintenance of the track infrastructure on the site during the operation of trains formed from cars with an axial load of 27 tons are given, as well as methods for determining the initial data for the calculation.

Authors provide values of the coefficient reflecting the change in the impact of vertical and horizontal forces on the railway line when passing freight cars with an axial load of 27 tons compared to analogue cars, and the coefficient of change of the main specific resistance to motion separately for loaded and empty cars.

Developed calculation algorithms and methods for obtaining baseline data allow an economic assessment of changes in infrastructure maintenance costs and fuel and energy resources for the operation of trains formed from cars with an axial load of 27 tons compared to those formed from cars with a load of 23.5 tons at the experimental section Kachkanar — Smychka.

The cost change assessment carried out in 2017 shows a generally definite economic effect, while there is a reduction in costs associated with the consumption of electricity for train traction as a result of the operation of the estimated cars in the experimental section and an increase in the cost of maintaining the track superstructure and the roadbed, which is quite expected for the conditions of the organization of traffic with increased axial loads.

Traffic safety and dynamic properties of the bridge deck of high-speed railway lines

High-speed lines are one of the safest modes of transport, despite the special conditions for moving the wheel along the rail. The urgent task is to ensure the sustainable motion of the wheel along the rail over the bridges in high-speed traffic. A feature of high-speed lines (HS lines) is the practical achievement of critical speeds that cause resonance of bridge deck structures. Cases of rolling stock derailments on high-speed lines are not frequent. The article provides information about rolling stock derailments on high-speed rail and its consequences. Standards for the stability of wheels on rails in various countries with high-speed rail were considered.

On the bridges of high-speed lines there are not many elements of the track that are strong dampers — the roadbed, its base and ballast. Due to the lack of damping elements, the damping properties of the bridge deck are of great importance. When driving over the bridge with critical speeds causing near-resonance oscillations, the force in the wheel — rail contact may drop to zero with the risk of derailment. Insufficient damping poses a threat to traffic safety. Thus, one of the most important dynamic parameters — damping — is a problem for a ballastless track on high-speed railway bridges. Considerations are given for the correct determination of stiffness associated with damping and affecting the interaction of rolling stock and bridge deck. It is shown that in case of insufficient damping at the fastening points on the bridges, the risk of derailment increases due to a fall of the vertical force below the permissible limit at the wheel — rail contact. Results of computer performed experiments are presented, confirming that it is precisely the significant oscillations of the bridge deck structures that are a safety hazard, since when the first car passes, the force at the contact of the wheel and rail for the first wheelset is safe. Requirements for damping parameters are given, ensuring reliable contact of the wheel and rail with significant fluctuations in bridge deck structures on high-speed lines. Results are presented, showing the dependence of required damping on the stiffness of intermediate rail fasteners.

Influence of duration and frequency of load application on the stress-strain state of the Track

In 2014–2016 on the Kovdor — Pinozero section of Oktyabrskaya Railway tests were carried out on the impact of cars with axial loads of 245.3 and 264.9 kN on the track in comparison with standard cars with an axial load of 230.5 kN. Test program included trips to five experimental sections of the track with the same construction of the track superstructure, but different parameters of the road bed. Tests carried out on the impact on the track of trains weighing from 2000 to 8000 tons at different axial loads of cars and moving at different speeds made it possible to estimate the dependence of the growth of vertical forces acting on the rail on the duration and frequency of load application. Work on the registration of vertical forces was carried out by the specialists of the Department “Tracks and track facility” of the JSC “VNIIZhT”. On the basis of the results obtained, a mathematical model was developed that describes the effect of increasing the impact of railcars on the track as the load application increases, allowing calculations for various characteristics of the base. In the future, it is planned to use this model to estimate the accumulation of deformations of the track with different characteristics of the base and variants of train load. Obtained results allow stating that the accumulation of track failures depends not only on the level of the axial load and the mass of the train, but also on the duration and frequency of the load application.

The work was carried out within the framework of the project of oriented fundamental research of the Russian Foundation for Basic Research on current interdisciplinary topics in the interests of JSC “Russian Railways” (ofi-m-RZhD competition No. 17-20-01152 “Scientific substantiation of methods for determining physical and mathematical patterns of track deformation development in dependence on the frequency composition and duration of load application in relation to the passage of heavy haul trains of various lengths and at different speeds, formed from cars with increased axial loads”).

Formation stages of the target model of integrated freight transport services

The need to create a strategy for a more advanced development of the competitiveness of industrial and manufacturing enterprises has been actualized considering actual conditions of reducing freight framework. Solution to this problem requires a comprehensive approach, involving a reduction in costs and an increase in revenues based on an assessment of economic performance. One way to solve this issue is to reduce the added value of the finished product. In order to reduce the cost of transport services, it is necessary to increase the efficiency of all participants in the transportation process integratively and with rational redistribution and interaction of transport business processes; exclude inefficient subjects and anti-competitors from the market of transport freight services. Article presents the target model of integrated transport services, ensuring the unity of transport service framework. Stages of the model formation were analyzed, taking into account the categories of traffic. New main quality criteria for consumers of integrated transport services has been established. Proposed system of forming the target model of an integrated transport service ensures a reduction in the cost of transportation, the added value of finished products, stimulates the growth of efficiency and competitiveness of industrial, production enterprises and subjects of transport services.

Consideration of the temperature factor of atmospheric air when determining standard consumption of fuel and energy resources for train traction

Influence of air temperature on the consumption of fuel and energy resources (FER) on train traction is due to a number of physical laws. The extent of this effect is specified in the Rules for Traction Settlement (RTS).

At the same time, when rationing FER consumption for train traction, a specialized methodical base is used, which involves a different approach to accounting for the effect of temperature on FER consumption for train traction. At the same time in different documents of this base, the effects of low temperature on the absolute and specific consumption of fuel and energy resources on train traction are taken into account in a different way, which is due to the lack of consensus among specialists on the way this factor is taken into account.

Specialists of JSC “VNIIZhT” carried out an analysis of a significant amount of driver’s routes data, results of which showed that the dependence of the specific flow rate on temperature, on the basis of which the corresponding influence coefficient is determined, needs to be periodically updated.

In addition, when technically standardizing the consumption of fuel and energy resources (for the locomotive crew work site), the temperature effect coefficients need to be calculated for a specific work area and direction of motion on it, while using the average network coefficient values will lead to errors.