Ukrainian Railways Research Articles

INVESTIGATION INTO THE CONDITIONS CAUSING TERMINAL-BOLTED TRACK GAUGE WIDENING AND CONSIDERATION OF IT IN THE CRITICAL GAUGE CALCULATION

In the current regulatory document UZ – Instructions for the device and the content Railways of Ukraine, the largest permissible value of track gauge – 1548mm, which was scientifically proved only for use as a sub-rail base wooden sleepers due to the possibility of the occurrence under certain conditions of falling of the wheels of the rolling stock, rails unfolding through the availability of pulling and screws. But, for tracks with concrete sleepers, rails unfolding not possible due to the hard bolt pressing pads to the sleepers and rails. In the presence on rails in the undocking way with reinforced concrete sleepers of the considerable sizes of lateral wear or corrosion damages of metal substrates in a zone of fastening of mortgage bolts, the certain value of dangerous width of a rail track is underestimated and economically inexpedient because of need of premature replacement of rail lashes. Therefore there is a need to clarify and justify the maximum allowable value of the width of a rail track with rail on the basis of concrete ties. To achieve this goal, it is necessary to conduct experimental studies with the worst real conditions of pressing the rails to the sleepers. The acute scientific task of determining maximum dangerous railway track gauge with reinforced concrete sleepers and fastenings of terminal-bolted track type has been set and solved on the base of the analysis of previous researches of leading scientists and scientific-research organizations of railway transport. Taking into account simultaneous actions of lateral force and track thrust force as well as all known tolerances and influences under the conditions of new maintenance profile of railway wheels of the most popular rolling stock, all the obtained results and recommendations have been differentiated according to the ranges of railway sections traffic volume and make it possible to increase running speeds and lifetime of long-welded rails substantially to use their service life to the maximum.

Challenges of liberalization for natural monopolies: Ukrainian railways

The article examines the approaches to transport policy at the state level, the particularities of the liberal approach and the specifics of the current liberalization processes in the rail transportation markets in Ukraine. Purpose of the study. To consider the main challenges facing the Ukrainian railways in the context of liberalization of the freight transportation markets, passenger transportation, locomotive traction and liberalization of access to infrastructure. Objectives of the study. The main tasks are: 1) to analyze the main approaches to regulation of the transport sector at the state level; 2) determine the role of the state in the implementation of liberalization policies; 3) to generalize the development of the liberalization processes at the present stage in the railway transport sector in Ukraine. Methods of research. The article uses structural-logical, economic-statistical and economic-mathematical methods, as well as comparative analysis, a graphical method. Results of the study. The analysis of the main approaches to regulation of the transport sector at the state level has been carried out. The necessity of combining the principles of paternalistic and liberal approaches in the combined transport policy is determined. A historical review of the process of reforming railways in Ukraine in the context of the theory of the stages of the life cycle of natural monopolies is carried out. The experience of development of the process of liberalization in the market of freight traffic is generalized. The necessary investments in the transport sector and railway transport in particular have been assessed. Scope of application of the results. Scientific results can be used and have been used by the Ministry of Infrastructure, implementing the state policy in the field of transport. Conclusions. Among the two polar approaches to transport policy, namely full non-interference or liberalization of the transport sector and a paternalistic approach, presupposes strict regulation of tariffs and a uniform form of ownership, the combined approach looks like an alternative in modern conditions, in which the principles of liberal (for commercial activities and tariffs) and paternalistic approaches. The choice of its application is confirmed, first of all, by the world practice of public administration in the transport sector. At the same time, the development of a competitive environment in the field of rail freight traffic in Ukraine will depend on the following factors: the introduction of EU railway directives, which are spelled out in the Association Agreement between the EU and Ukraine of 2014; the subsequent separation of regulated and unregulated activities (the monopoly sector from potentially competitive) in the organizational and economic sense. After all, while the actual definition of the sphere of freight transportation as a competitive sector, Ukrzaliznytsya, as the owner of the infrastructure, enjoys unlimited powers with respect to other business entities in this market. It is necessary: reorganization of potentially competing segments; the establishment of civil liability of all market participants, as well as the conditions for their interaction; bringing the investment process in line with market requirements; improving the mechanism for setting tariffs for transportation and the adoption of the rules for non-discriminatory access to infrastructure.

СТРАТЕГІЧНІ НАПРЯМКИ РОЗВИТКУ ЗАЛІЗНИЧНОЇ ГАЛУЗІ В УМОВАХ ЄВРОІНТЕГРАЦІЙНИХ ПРОЦЕСІВ

В статті розроблено та обгрунтовано стратегічні напрямки розвитку залізничної галузі в умовах євроінтеграційних процесів, що вимагає прийняття кардинальних рішень у зміні системи управління даної галузі. На підставі аналізу результатів роботи залізничного транспорту були визначені причини зниження прибутку пасажирських перевезень та запропоновані заходи підвищення ефективності їх діяльності, з урахування сучасних світових тенденцій організації роботи даного виду транспорту.

УКРАЇНСЬКЕ КОРІННЯ ПРОФЕСОРА В.О. СОКОВИЧА, ЯК ОСНОВА ЙОГО НАУКОВОГО ТА СУСПІЛЬНОГО СВІТОГЛЯДУ

The article gives an overview of the origin of the family, the childhood, the acquisition of secondary education and the start of education at the higher school of the outstanding Ukrainian railway scientist, the founder of the scientific school "Organization of Railway Transportation" Volodymyr Sokovich. The biography of his father, Olexandr Sokovich (1840-1886), a well-known Ukrainian teacher, teacher of mathematics, physics and geography, author of a number of textbooks and teaching aids on these subjects, the head of several real colleges and the Belotserkovsky Gymnasium is highlighted. Particular mention is made of membership of O. Sokovich in the South-Western Division of the Russian Geographical Society, which became the center of the scientific and socio-cultural life of Kiyv and Ukraine of its time. It was also determined that his elder brother Evgen Sokovich (1864 - 1946) played a decisive role in the choice of the future scientist for the railway worker. which later, in the period of existence of the Ukrainian People's Republic, became Minister of Railways of its government. A number of facts of his activity are highlighted in this post. The period of training of Volodymyr Sokovich in the Second Kyiv Gymnasium is analyzed, the natural inclination of the schoolboy to exact sciences is noted - especially to mathematics. In connection with which, he began to receive higher education at the Physics and Mathematics Faculty of Kyiv University of St. Volodymyr, and only then entered the St. Petersburg Institute of Railway Engineers. Summarizing the work, we can state that the article identifies the reasons that gave the impetus for the formation of an outstanding scientific personality of the Doctor of Technical Sciences, Professor Volodymyr Sokovich.

FORMATION PECULIARITIES OF FINANCIAL RESOURCES OF PJSC «UKRAINIAN RAILWAY»

Purpose. The need for technological modernization of the railway industry in Ukraine, creation of favorable conditions for investment and introduction of innovations in the industry require significant financial resources. The purpose of the article is investigation of possible sources of attracting financial resources necessary for development of Ukrainian railway transport, in particular, during further organizational arrangements and procedures for the railway industry corporatization to search for ways to optimize them. Methodology. During research the methods of comparison, scientific search, analysis and synthesis were used to study the existing sources of financing for corporations abroad and at Ukrainian enterprises. Findings. Analysis of the existing and search for more efficient sources of financial resources necessary for financing Ukrainian railway transport modernization in the process of the railway industry corporatization is carried out. The growth of the financial results share in the amount of internal own resources is achieved by taking measures to increase profits. A significant part of the economic activities financing can be provided by issuing corporate bonds with the presence of positive effect of the financial leverage. Accounting of the financial leverage effect is an efficient tool for optimizing the structure of the share capital and determining the expediency of loan resources. In the process of corporatization, PJSC «Ukrzaliznytsia» should create an efficient system of financial resources that fully takes into account the specifics of its activities, motivates to increase labor productivity with the ultimate purpose of ensuring the external competitiveness of the Ukrainian railway industry. Originality. Based on the study of scientific and methodological sources, as well as the analysis of sources for financing the economic activities of railway transport, the ways of their optimization are proposed. Practical value. Introduction of the proposed approaches will make it possible to justify the economic feasibility and proportionality of internal and external sources of the railway transport financing under the conditions of corporatization.

МЕТОДОЛОГІЧНІ АСПЕКТИ МАРКЕТИНГОВИХ ДОСЛІДЖЕНЬ ПОПИТУ І МОТИВІВ СПОЖИВЧОЇ ПОВЕДІНКИ ПАСАЖИРІВ ЗАЛІЗНИЧНОГО ТРАНСПОРТУ ДАЛЕКОГО СПОЛУЧЕННЯ

The article draws attention to the lack of an integral methodology for marketing research in Ukraine's railway transport. The necessity of marketing researches of demand for passenger transportation and the factors influencing its change is proves. It is emphasizing that the purpose of marketing research is not only to fix changes in demand, but also to identify goods and services, in which passengers need the most. A scheme for filling the database on the demand for transport services is proposes. Such a database should be the basis for estimating current demand and forecasting demand for the future. The article presents controlled and uncontrolled factors affecting the demand of passengers for basic and additional services. At the same time, key determinants of demand are identifies, which are subject to more careful observation and research. The classification of demand factors into price and non-price factors is considered. It is emphasized that the focus in marketing research should be paid to non-price factors and, first of all, to the expectations of passengers. A list of information that marketing research should provide to understand the behavior of transport service consumers is provided. Attention draws to the need for a more thorough study of the intentions of consumer behavior, since such an analysis will reveal the services that can bring consumers the greatest satisfaction. The need to take into account the specific nature of the motivations of passengers, which are complex, ambiguous and multidirectional, is substantiates, which is due to the peculiarities of the transport service, its differences from other services and from transport services in other types of long-distance passenger transport. The article says that consumer motives are bases on the behavior of passengers, which are divides into rational and emotional motives. It is emphasizes that more attention should be paid to emotional motives, as they are more important for passengers. The article contains a list of rational and emotional motives that determine the choice of passengers of one or another type of transport, such as vehicles. In conclusion, we propose an algorithm for marketing research of the determinants of demand and the motives for consumer behavior of long-distance railway transport passengers.

УДОСКОНАЛЕННЯ РОБОТИ СЕРВІСНИХ ЦЕНТРІВ НА ЗАЛІЗНИЧНИХ ВОКЗАЛАХ ПРИ ОБСЛУГОВУВАННІ ПАСАЖИРОПОТОКУ

In the near future, the Ministry of Economic Development forecasts a moderate increase in the provision of transportation services, given the increase in passenger traffic and correspondingly the volume of services that are provided to passengers. The reform and development of rail transport in the provision of services will increase the passenger traffic of the railway by 5%. The study is based on the study of the features and specific features of the operation of the station service centers, the development of new technologies for passenger service. The demand and the list of services provided by service centers have been determined. The most significant services were identified according to the classification criteria, namely the income from the provision of services and the need for the number of calls. A model has been developed that takes into account new additional services in the organization of passenger transportation, which, according to the results of the research, are in demand among customers. In this paper, ABC and XYZ analysis methods are used to study and rank a variety of services. During the modeling, the passenger traffic was used at the statistical level, considering how many passengers are interested in this or that service. Analysis of services provided by rail transport, identified shortcomings in passenger service technology. Considering the prospects of integration of the Ukrainian railways into the European transport network, the current task will be to eliminate the shortcomings in the provision of services to railway users. Ranking of the list of services by criteria of classification the importance and profitableness allows to exclude refusals in service system.

КОНЦЕПЦІЯ ЖИТТЄВОГО ЦИКЛУ В ТЕОРЕТИЧНОМУ ПІДХОДІ ДО ВИБОРУ ВАРІАНТУ ІНВЕСТИЦІЙ В ОНОВЛЕННЯ ПАРКА ТЯГОВОГО РУХОМОГО СКЛАДУ

Updating of hauling rolling stock of railway transport can be realized both due to purchase of new technique and due to modernisation of existing one. In both cases it requires considerable capital investments, especially when purchase or modernisation options are examined with bringing in of foreign producers. In the conditions of limitation of investments a railway transport needs realization of engineering and economical analysis and scientific rationale for choosing of possible variants of new technique updating. Thus engineering and economical calculations must take into account the following stages: productions of progressive types of technique, its maintenance and utilization. These stages are the protracted period of time (30-40) during this period such changes are possible: in the national economy; volumes of transportations; cost indexes and normative base; indexes of the technical state (of reliability, economy, productivity, ecological safety of technical equipments). Presently abroad for the estimation of efficiency of investment projects conception of life cycle cost (Product Life Сус1е Соst - LCC) is widely used. The problems related to the realization of the program of hauling rolling stock updating of locomotive economy of the Ukrainian railways are analysed in the article. Theoretical positions of choice of variant of hauling rolling stock updating are considered taking into account its life cycle. It is defined that the use of economic indicator of life cycle cost is one of basic criteria at the choice of variant of decisions of investment character on a long-term period. It is defined that proposed scientifically-applied approach is necessary to take as a basis of feasability study of alternative variants of investment decisions of locomotive economy development of the Ukrainian railways.

Studying of the power modes in the traction line for ensuring the high-speed traffic

The object of research is the power regimes in traction power systems for both centralized and distributed power when introducing high-speed traffic. The introduction of high-speed traffic on electrified railways of Ukraine has begun a number of restrictions in the applied system of traction power supply of centralized power supply. These include not only the impossibility of providing the necessary voltage level of 2.9 kV, but also the low efficiency of the aggregate power of traction substations. In this case, the applied traction power system does not allow to provide the necessary level of specific power in the traction network. Applicable technical means and measures to strengthen the traction network do not allow, in most cases, to provide regulatory requirements for the organization of high-speed traffic. An analysis of modern research shows that overcoming these disadvantages is possible due to the application of a distributed power supply system to the traction network. To date, sufficient options have been developed for constructing such systems, but in this paper, as an alternative, a system was considered with the distribution of the aggregate power available in the system of centralized power in the inter-substation zone. At the same time it was reasonable to reduce the power of the traction substation to the level of 10 MW. During the study of power regimes in comparable traction power systems, the results of experimental studies and simulation modeling of the operating modes of the comparable systems were used. Calculations were taken into account not only the specifics of the traction load, but also its impact on the load capacity of the contact suspension. As a result of this approach, it has been shown that the distributed traction power system allows to fulfill the regulatory requirements for providing high-speed traffic. With its application, the consumption of electric energy for traction of trains is reduced by 40 %, the specific power of traction network increases by 90 %, and the load factor of traction substations – by 60 %. The proposed innovative approach to providing the necessary power mode in the traction line for the organization of high-speed traffic allows to preserve the existing infrastructure on existing electrified section of direct current. This approach allows the application of various types of electric rolling stock and provides the required capacity of the railways.

CALCULATION-EXPERIMENTAL DETERMINATION OF THE PROBABILITIES OF APPEARANCE OF DIFFERENT IN MAGNITUDE WEAR OF TRACTION GEARS

The importance of studies aimed at assessing the residual resource of the components and components of the mechanical system of the rolling stock operated on the Ukrainian railways is substantiated. As the basic unit of the rolling stock involved in the suburban transportation of passengers, electric trains are allocated. The importance for the mechanical system of motor-car rolling stock traction gears was noted. The necessity of determining the laws of distribution of the main characteristics of the traction gear operation is substantiated. The expediency of considering the value of tooth wear along the dividing circle as one of the main characteristics of the gear drive operation was noted. Features of the statistical analysis of the results of measuring the gear teeth and the wheels of traction gears of ER2, ER2P and ER2T electric trains operating on the southern railway during a three-year period of operation (2015-2017) are considered. The tooth thickness values for dividing chords are presented in the summary table in the form of arrays for gears and gears with the corresponding value and series of rolling stock, the date of measurement. Based on the results of statistical processing of these arrays, corresponding matrices are formed, the elements of which are the probabilities of occurrence of different wear, the corresponding mathematical expectations and the general variance. Using the obtained matrices for the traction gears of the series of electric trains studied, histograms and corresponding laws were constructed to distribute the probabilities of occurrence of a particular wear. It is noted that during the analysis of the obtained diagrams, laws were obtained which correspond to the steady-state regime on the wear curve and do not exceed the allowable or reject dimensions. Prospects for using the results obtained in predicting the residual service life of traction gears of tractive rolling stock are considered.

PROPOSALS FOR IMPROVING THE PROCESS OF FORMING PROGRAMS OF REFORMING THE RAILWAY TRANSPORT INDUSTRY

Purpose. The purpose of the work is to develop proposals for improving the process of forming measures and programs for reforming the railway transport industry of Ukraine in the process of European integration based on research, comparison and generalization of information. Methodology. A study of the content and the main provisions of legal acts declaring the conditions for the reform of the railway transport was carried out using analysis and synthesis methods. Methods of the system approach, comparison and generalization of the obtained data allowed developing proposals for improving the process of the formation of activities and programs. Findings. The need for reforming Ukraine's railway transport has been under consideration since 2006, but for a long time reform was limited only to the development of reforming plans and programs. Not being implemented within the framework of one program, the measures were reflected in the next or parallel one, with the corresponding change in the terms. The carried out analysis of their implementation does not allow talking about inactivity or denying the existence of positive changes, however, given the duration of the period 2006-2017, they occur very slowly. This situation requires new approaches to the development of programs and activities, as well as assessing their implementation, one of which is proposed in the work. Originality. The work justifies the need to evaluate the implementation of measures and programs for reforming the railway transport industry by two criteria: legal and practical. The developed basic principles for the formation of programs for reforming and developing the railway transport industry provide an opportunity to receive timely and reliable information on the status of their implementation. Practical value. We obtained the possibilities of constant monitoring of the state of financial support for reforms and directions of use of funds, which will prevent their misuse and significantly accelerate the implementation of certain activities, and then increase their effectiveness.

Resource-saving technologies of railway transportation of grain freights for export

The research objective is to increase the efficiency of export railway transportation of grain freights in Ukraine by the introduction of consignor routing, a concentration of loading of grain on junction elevators and the organization of the movement of grain routes according to the schedule. According to the researchers in USA and EU, one of the effective directions for decreasing the expenses in a logistic chain of grain delivery to ports is consignor routing of railway transportation. Consignor routing of transportations of grain freights provides a concentration of their loading at junctions. The choice of junctions is proposed to be carried out on the basis of methods of the cluster analysis. For formation of regions for a concentration of grain loading the theory of sets and multicriteria optimization are used. As a result, on the basis of the modified simplex method are chosen 24 regions of possible concentration of grain loading that cover 70 stations on Ukrainian railways providing 7,5 million t consignor routing for grain in a year with minimal additional expenses. The assessment of the efficiency of railway transportation routing of grain freights is calculated with use of the developed simulation model. Researches showed that application of consignor routing allows to reduce a turn-round cycle for grain wagon in a logistic chain of deliveries up to 27%, and application of the schedule for consignor routes allows to reduce a turn-round cycle up to 62%, in comparison with transportation by car loading. Thus, as showed the calculations executed for one of the directions of grain transportation for export, the necessary operation park of grain-carrier wagons is reduced twice, thereby allowing to cut logistic expenses on a delivery of the Ukrainian grain through seaports to the world markets.

СОЦІАЛЬНА ВІДПОВІДАЛЬНІСТЬ НА ЗАЛІЗНИЧНОМУ ТРАНСПОРТІ УКРАЇНИ

In the article the approaches to the social responsibility of business are investigated. The world experience of formation of models of social responsibility of business is analyzed. For Ukraine, the influence of governments on the formation of the system of corporate social responsibility, the strong role of international institutions and donors in the development of the concept of corporate social responsibility, the insignificant role of public and expert organizations and the media in shaping the social responsibility of business are characteristic.Features of the system of social responsibility on the railways of Ukraine are considered. Systemic changes in the economy and in the industry had a negative impact on the state of social responsibility in rail transport. For the further progressive development and active growth of public corporation "Ukrainian Railways" it is necessary to give priority to social policy issues and constantly raise the level of responsibility not only for clients but also for their employees.

TRANSPORT ACCIDENTS DISTRIBUTION AT UKRAINIAN RAILWAYS ACCORDING TO CATEGORIES DEPENDING ON SEVERITY OF CONSEQUENCES

Purpose. The article aimed at developing a methodology for transport accisents distribution according to criterion of average material damage and establish financial limits between the existing types of transport accidents. Methodology. Nowadays, at the Ukrainian railways, transport accidents are classified according to the severity of consequences which are expressed in physical quantities. The existing classification system is inferior to the classification system of transport accidents, which operates in the territory of the European Union (EU). Transport accidents in the EU countries are classified both by type and by criterion of material damage. To distribute transport accidents by categories depending on the severity of the consequences at the Ukrainian railways the method of the nearest neighbor is used. It takes into account average losses from transport accident, its feature is the possibility of establishing financial limits. Findings. The article proposes an efficient method for distributing transport accidents at the Ukrainian railways according to the categories depending on the severity of consequences using cluster analysis. The presented results of calculations allow us to distribute the transport accidents into three groups and establish the financial limits between them. Originality. It was improved the method of distribution of transport accidents by categories depending on material losses. According to it, transport accidents are divided into three groups. For the first time, financial limits were proposed between groups of transport events. We propose further research to confirm the size of financial limits. Practical value. As a result of research, it was possible to evaluate transport accidents not only by severity of their consequences, but also by the criterion of material damage. This approach also enables us to evaluate the state of traffic safety at certain sections, stations or railway directions. On the basis of obtained results, further development of classification system of transport accidents, as well as its integration into the European classification system, is possible.

ІННОВАЦІЙНИЙ РОЗВИТОК ВАГОННОЇ ДІЛЬНИЦІ

One of major constituent parts of the railway transport is a carriage department , which provides safe and quality transportations with f reight and passenger carriages and forms such quality parameters of a transport service as rhythm, reliability, safety, timeliness and others like that. Therefore a timely task is a search of ways of development of both carriage department and railway carriage station s, for what it is necessary to create proper scientifically-methodical base. The essence of development of railway carriage station is determined in this article on the basis of analysis of existent determinations of term innovative development. It is a purposeful systematic process of positive changes of the quality state of all railway carriage station subsystems by introduction of innovations (worked out by both external and own forces) in activity of railway carriage station with the purpose of achievement of both aims of activity and strategic aims of development of the higher level systems - carriage department and public joint-stock company Ukrainian railway.

PROJECT SCOPE MODELLING OF ARCHITECTURAL AND SPATIAL ACCESSIBILITY OF RAILWAY STATIONS

Current approaches in the organization of the architectural and spatial accessibility of civil engineering objects are analyzed. The focus of the research is state building codes required for the development of architectural design and technical solutions of the railway station complex. It is noted that passengers with reduced mobility include not only disabled people but also older people, pregnant women, parents with children, people with temporary injuries, etc. Inclusive components in the functioning of the railway companies «Ukrzaliznytsya» (Ukraine) and Deutsche Bahn AG (Germany) are compared. The matrix for tracking the requirements of low-mobility groups of passengers in the projects of the organization of the architectural and spatial accessibility of the railway station complex has been developed. The seven groups of requirements to the design of the organization of the railway station availability are formed: barrier-free movement on the station and the adjacent territory; parking area; inputs and outputs, doors; stairs and ramps; corridors, transitions to railway platforms; bathrooms; railway ticket offices, luggage storage, payphones, ATMs. The mathematical description of models of the estimate of architectural and spatial accessibility of the railway station complexes for passengers with limited mobility is offered. It is noted that the estimate of the inclusiveness of design solutions of the railway station complex by passengers with limited mobility groups can be integrated into the procedure for selection of projects for the formation of the programs and portfolios projects content, oriented to the architectural and spatial accessibility of Ukrainian railway stations. Audit of architectural and spatial accessibility of the railway station complex «Kharkiv-Passazhirsky» is carried out. According to its results, «weak spots» in accessibility from the point of view of the needs of all different low-mobility groups of passengers were identified.

Research of safety indicators of diesel train movement with two-stage spring suspension

The problem of the interaction of rolling stock with the rail track has been analyzed in the present paper. It has been established that in the process of transport science development a number of methods for determining the causes of wheel pairs derailment are developed, which, in a varying degree, take into account the peculiarities of their interaction. The problem of choosing the most accurate method for estimating the causes of rolling stock derailment becomes more complicated because of the lack of sufficient experimental data that would allow us to verify the adequacy of the models. The indicators of stability of the wheel against derailment, which are used on the railways of Ukraine and Europe, have been examined. Their dependences on the speed of movement were derived. It has been established that the increase of the speed of motion leads to the increase of the interaction power of the rolling stock with the rail track, which may, under certain operational parameters, provoke its derailment. As a result of the calculations, it has been shown that the use of norms for car design and calculation used on Ukrainian railways can lead to an inadequate estimation of traffic safety parameters, since it does not take into account the unevenness of the railway track. It has been established that the requirements of BS EN 14363: 2005 European norms are stricter in comparison with the norms for calculation and evaluation of the bearing elements strength and dynamic qualities of motor-vehicle rolling stock used on Ukrainian railways. A comparison of the experimentally and theoretically calculated values of the stability margin coefficient against wheel derailment of the first wheel pair of the diesel train car was carried out.

Reused rails for underground systems

The structural components of the rail track, including rails, deteriorate in operation. However, some of them retain their operational characteristics and can be reused. This practice has found wide application on Ukrainian railways and shown a lot of self-evident advantages, among which the basic one is a rational use of material and technical means. Besides, development of a used rail system for underground railways may also optimize the track facility system for such specific conditions. The article presents results of the research into the change of the crumbling depth on the roll surface (the main rail defects of underground railways); it allowed the authors to conclude about the possibility to reuse rails for underground systems. Moreover, assessment of interacting forces in the wheel/rail system and the crumbling volume made it possible to determine rational application for used rails. The proposed system takes into account all the features of operating the railway track in underground systems, and also allows more efficient use of the residual rail resource without reducing the necessary level of traffic safety.

ВДОСКОНАЛЕННЯ МЕТОДУ ВИПРОБУВАННЯ ТА ТЕХНІЧНОГО ДІАГНОСТУВАННЯ ГІДРОДЕМПФЕРІВ НА ВИПРОБУВАЛЬНОМУ СТЕНДІ ИГК-90.1

The article examines ways to improve the test method and technical diagnostics of hydraulic dampers of traction rolling stock on the test stand of ИГK-90.1 which are operated in the production divisions of PJSC «Ukrainian Railways». A brief review of modern test benches is given and the type of the test stand ИГK-90.1 is selected for its further modernization. The calculations of the energy capacity of hydraulic dampers, which formed the basis for software and modernization of the design of the test stand ИГK-90.1, are given. At the indicated type of test stand, the authors carried out experimental studies of the hydrodynamic type НЦ1100, graphical dependences were obtained for the force and resistance parameter, as well as the energy capacity from the piston displacement speed. In addition, a graph of the temperature change along the outer vertical surface of the cylinder body during the test is obtained. On a concrete example test of hydraulic damper of type НЦ1100, the expediency of introducing a new defining technical parameter (energy-capacity) for the evaluation of the operability and functionality of hydraulic diodes for their main purpose has been proved. The authors obtained an analytical expression for the transformation balance of the energy loading of the hydraulic damper to the work on the piston movement and the thermal energy of heating the working fluid in the cylinder. On the basis of this, the software of the ИГK-90.1 computer bench has been improved, which made it possible to obtain graphical dependencies of the hydro damper’s energy intensity on the piston moving speed. In the long run, it is planned to further upgrade the software to the PC booth to conduct resource tests of hydraulic damps to form a database, which will be the basis for the thermal diagnosis of the technical state of the hydraulic damp. The prospect of applying a new technical parameter in practice and using the obtained research results in the development and implementation of an automated remote thermal control system for hydraulic diodes during their operation on railway transport is indicated.

A longer service life of intermediate elastic fastenings KPP-5 due to application of pads PRP-3.2

Since 2003 Ukrainian railways have used KPP-5 intermediate elastic fastenings. These fastenings unlike their predecessors (for example, terminal-bolted fastenings (KB) widely used on railways), first of all, have fewer elements. The KPP-5 fastening does not include screw joints, which considerably increases the pressing force between rail and tie, and resistance to track displacement forces. This may lead to reduction of the total labour input for routine track maintenance due to cutback of track works needed for mounting terminal and insert bolts. The article deals with forecasting the operational life of PRP 3.2 (9mm depth) and PRP 3.2.1 pads (10mm depth). In engineering the operational life is a time interval (for the railway track – tonnage passed) during which the element fulfils its functions. One of the main reasons why the assembly unit KPP-5 fails is low pressing forces between rail and tie. It occurs due to many processes; among the basic ones is the changed characteristic of underrail pads. And the application of new types of pads – PRP 3.2 (9mm) and PRP 3.2.1. (10mm) may solve this problem.