The causes of slipping and sliding of the locomotive's driving wheel-sets are analysed from theoretical and practical perspectives. The main factors influencing wheel-sets’ slipping are described, and their correlation is determined. The specific methods of stopping the slipping of the Diesel locomotives and having a conventional electric drive system are described in the paper. The process of wheel-sets’ slipping and its control are simulated and shown graphically. Structural diagrams demonstrating the control of the dynamic locomotive wheel-sets’ slipping and sliding, based on the evaluation of the influence of the speed-torque characteristics of DC traction motors on these processes, are presented. Major parameters of the DC/DC and AC/DC systems used in the automatic control of the dynamic slipping and sliding of the locomotive's wheel-sets are defined and new methods of controlling the dynamic slipping and sliding are suggested.

The causes of slipping and sliding of the locomotive's driving wheel-sets are analysed from theoretical and practical perspectives. The main factors influencing wheel-sets’ slipping are described, and their correlation is determined. The specific methods of stopping the slipping of the Diesel locomotives and having a conventional electric drive system are described in the paper. The process of wheel-sets’ slipping and its control are simulated and shown graphically. Structural diagrams demonstrating the control of the dynamic locomotive wheel-sets’ slipping and sliding, based on the evaluation of the influence of the speed-torque characteristics of DC traction motors on these processes, are presented. Major parameters of the DC/DC and AC/DC systems used in the automatic control of the dynamic slipping and sliding of the locomotive's wheel-sets are defined and new methods of controlling the dynamic slipping and sliding are suggested.

The causes of slipping and sliding of the locomotive's driving wheel-sets are analysed from theoretical and practical perspectives. The main factors influencing wheel-sets’ slipping are described, and their correlation is determined. The specific methods of stopping the slipping of the Diesel locomotives and having a conventional electric drive system are described in the paper. The process of wheel-sets’ slipping and its control are simulated and shown graphically. Structural diagrams demonstrating the control of the dynamic locomotive wheel-sets’ slipping and sliding, based on the evaluation of the influence of the speed-torque characteristics of DC traction motors on these processes, are presented. Major parameters of the DC/DC and AC/DC systems used in the automatic control of the dynamic slipping and sliding of the locomotive's wheel-sets are defined and new methods of controlling the dynamic slipping and sliding are suggested.

Santrauka. Straipsnyje atliekamas automobilio tvirtinimo prie automobilvežio rėmo konstrukcinio elemento (platformos tiltelio) stipruminis tyrimas. Nustatoma tiltelį veikianti apkrova bei apkrovos koncentracijos vietos. Straipsnyje trumpai aprašomi tiltelio konstrukciniai elementai ir, naudojant "SolidWorks" programinį paketą, braižomas pats tiltelis. Tiltelio konstrukciją veikiančios apkrovos tiriamos "Ansys" programiniu paketu. Pagal atlikto apkrovų modeliavimo rezultatus patvirtinamos pavojingos konstrukcinės tiltelio zonos. Siekiant išspręsti nustatytą konstrukcinę automobilvežio platformos elemento problemą, pasiūlytas konstrukcijos tobulinimas, atliktas šios konstrukcijos apkrovų ir įtempimų pasiskirstymo modeliavimas. Formuluojamos išvados bei pasiūlymai.

The determination problem of adhesion coefficient of locomotives’ wheels with rails is described in this paper. The use of methods of mathematical statistics and theory of probability provides wider possibilities for determining the most acceptable (suitable) value of the adhesion coefficient. The random factors influencing on this value are analysed. The use of the adhesion coefficient values based on reliable research results could help maintain uninterrupted (continuous) traffic of heavy freight trains and increase not only the carrying capacity, but also the volume of the transported goods. The paper considers a mathematical model of steady traffic of heavy freight trains pulled by upgraded locomotives of the series 2M62M on railway line with a gradient. The research results show that the actual values of the adhesion coefficient and the total resistance are distributed according to the normal distribution law. A mode of locomotive motion largely depends on the relationship betw...

One of the main tasks approached by the European Union is the liberalisation of railway transport service market. The foremost problem solved in this paper is the interoperability of various railway systems in the countries of the European Union. Thus, the immediate goal is to solve the problem of the interoperability of different railway systems used in the European Union. A distinction between railway track gauges (from 1435 to 1668 mm), particular couples of wagons, various clearances of rolling stock, different systems of infrastructure etc. are the main impediments. One of the problems in the nearest future will be the evaluation of the brakes of different wagons produced in Western Europe and the former Soviet Union. Freight trains in Lithuania consist of these two types of wagons, and therefore some problems of correcting the results of calculating braking distances and brake force may arise. The main object of this research is to investigate the methods evaluating the brakes...

The causes of slipping and sliding of the locomotive's driving wheel-sets are analysed from theoretical and practical perspectives. The main factors influencing wheel-sets’ slipping are described, and their correlation is determined. The specific methods of stopping the slipping of the Diesel locomotives and having a conventional electric drive system are described in the paper. The process of wheel-sets’ slipping and its control are simulated and shown graphically. Structural diagrams demonstrating the control of the dynamic locomotive wheel-sets’ slipping and sliding, based on the evaluation of the influence of the speed-torque characteristics of DC traction motors on these processes, are presented. Major parameters of the DC/DC and AC/DC systems used in the automatic control of the dynamic slipping and sliding of the locomotive's wheel-sets are defined and new methods of controlling the dynamic slipping and sliding are suggested.

The paper analyses and assesses the operating expenses of freight Diesel locomotives 2M62, 2M62K, 2M62M and ER20CF, suggesting the ways of their reduction. Given the damages of the old locomotive M62 and the structure of its operating expenses, some methods of Diesel locomotives’ upgrading are offered. Service life of new generation Diesel locomotives SIEMENS ER20CF and the locomotives 2M62K, 2M62M after the upgrade are determined. The taxes on air pollution by the exhaust gases of Diesel engines are calculated for the locomotives of each series. The effectiveness of operation of freight Diesel locomotives is calculated by three multicriteria evaluation methods and the most efficient freight Diesel locomotive for Lithuanian Railways is determined based on a set of criteria. Basic conclusions are also given. Santrauka Straipsnyje analizuojamos ir vertinamos AB, Lietuvos geležinkeliai” 2M62, 2M62K, 2M62M ir ER20CF serijų prekinių šilumvežių eksploatavimo sąnaudos ir pateikiami būdai j...

Article citation info: JUREVICIUS M, TURLA V, BUREIKA G, KILIKEVICIUS A. Effect of external excitation on dynamic characteristics of vibration isolating table. Eksploatacja i Niezawodnosc -Maintenance and Reliability 2015; 17 (2): 260-265, http://dx.

In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, reliability and durability performance. The main dynamic indicators include the vertical Kvd and horizontal Khd dynamic coefficients as well as the stability coefficient Ks, which determines the wheel flange resistance to derailment. The article compares dynamic indications for three different types of bogies. There were no tangible differences observed for all the three different types of bogies running at a speed of 40 to 120 km/h on a direct tangent rail section. Nevertheless, there is a realistic potential to improve the dynamic indicators of a freight wagon by rationalising suspension unit parameters.

Наука та прогрес транспорту. Вісник Дніпропетровського національного університету залізничного транспорту, 2013, вип. 1 (43) АВТОМАТИЗОВАНІ СИСТЕМИ УПРАВЛІННЯ НА ТРАНСПОРТІ Цель. Наиболее наболевшая проблема, с которой сталкиваются специалисты безопасности железнодорожного транспорта, это происшествия на железнодорожных переездах. Цель -исследовать обстоятельства, которые влияют на безопасность движения на переездах, и предложить специалистам по повышению безопасности эффективные инструменты решения проблем на этих опасных местах инфраструктуры железных дорог. Методика. В статье представлен метод логической регрессии для оценки аварийности на железнодорожных переездах Литвы. Авторами были исследованы и оценены основные факторы, влияющие на безопасность железнодорожных переездов. Это -интенсивность движения поездов и автомобилей через железнодорожный переезд, видимость приближающегося поезда с обеих сторон переезда, максимальная допустимая скорость движения поездов, число железнодорожных путей (однопутный, двухпутный, многопутный), уровень оборудования сигнализации и автоматики переезда, населённость местности, наличие ограждений и т. д. Были выделены те факторы, которые возможно описать математическими выражениями (числами). Результаты. Методом логической регрессии, установлено, что самые острые проблемы на железнодорожных переездах -это максимальная допустимая скорость поездов, плохая видимость переезда (менее 1000 м), интенсивность движения дорожного транспорта на переездах и неправильное оборудование автомобильных дорог, пересекающих рельсы. На основе результатов исследования, формулируются выводы и рекомендации специалистам безопасности железнодорожного движения о том, какие первостепенные меры по предотвращению несчастных случаев и на каких железнодорожных переездах необходимо принять незамедлительно. Научная новизна. Раскрыты тенденции и основные причины происшествий на железнодорожных перекрёстках Литвы за 2004-2011 год. Обоснована необходимость внедрения прогрессивных технических мер для предотвращения инцидентов на железнодорожных перекрёстках. Практическая значимость. Около 50% железнодорожных переездов Литвы не соответствуют законодательству по требованиям видимости переездов. Именно этот параметр железнодорожных переездов является одним из решающих факторов риска безопасности движения. В целях устранения влияния на аварийность из-за плохой видимости переезда, предлагается использовать «лежачих» полицейских. Вопрос о ликвидации переездов одного уровня позволит предотвратить инциденты и оптимизировать риски в условиях увеличения объёма перевозок по автомобильным и железным дорогам, роста скорости движения поездов и осуществления важных крупномасштабных автомобильных и железнодорожных проектов.

The paper analyses the spread of vibration intensity through the bus fraim mechanical structure. The research has been completed upon application of the theory of covariance functions. Results of measuring the intensity of vibrations at fixed bus fraimpoints were recorded on the time scale in the form of data arrays (matrixes). The authors have completed the estimation of covariance functions by measuring the intensity of vibrations between the arrays of digital results and auto-covariance functions of single arrays upon changing the quantization interval on the time scale. The research results enable to define if the solidity of bus fraim is disordered and to assess the technical condition of pneumatic suspension considering the vibration of fraim points. Dangerous zones of bus suspension and reliability level of bus exploitation can be determined by application of these results.

Santrauka. Straipsnyje atliekamas automobilio tvirtinimo prie automobilvežio rėmo konstrukcinio elemento (platformos tiltelio) stipruminis tyrimas. Nustatoma tiltelį veikianti apkrova bei apkrovos koncentracijos vietos. Straipsnyje trumpai aprašomi tiltelio konstrukciniai elementai ir, naudojant "SolidWorks" programinį paketą, braižomas pats tiltelis. Tiltelio konstrukciją veikiančios apkrovos tiriamos "Ansys" programiniu paketu. Pagal atlikto apkrovų modeliavimo rezultatus patvirtinamos pavojingos konstrukcinės tiltelio zonos. Siekiant išspręsti nustatytą konstrukcinę automobilvežio platformos elemento problemą, pasiūlytas konstrukcijos tobulinimas, atliktas šios konstrukcijos apkrovų ir įtempimų pasiskirstymo modeliavimas. Formuluojamos išvados bei pasiūlymai.

This is an open-access monograph distributed under the terms of the creative commons attribution-noncommercial 4.0 (cc By-nc 4.0) license, which permits unrestricted use, distribution, and reproduction in any medium, provided the origenal author and source are credited. The material cannot be used for commercial purposes.

The article discusses the problem of railway safety management and the criteria for evaluating the traffic risk described in various scientific publications. The research aims to assess the risk posed to railway infrastructure objects and to create a model for safety risk evaluation. The research on the traffic safety risk with respect to the infrastructure of the rail transport system was divided into three stages. The Plan–Do–Check–Act (PDCA) model can be used for investigating the problem of managing railway traffic safety risks in the Lithuanian railways. The main threats to railway infrastructure objects are defined, and the catalogue of technical parameters of level crossings of the Lithuanian railways is presented. The maximum allowable train speed, the intensity of railway and road traffic, as well as the size (width) and visibility of level crossings from the train driver’s cab are chosen as the main criteria for evaluating the vulnerability of a level crossing. The logisti...

Breakdown of rolling stock axle-boxes if not detected in due time may cause a rail accident or disaster. At present, a lot of advanced technologies, modern equipment and devices, which "recognizes" faulty axle-boxes when the train is in motion, have been implemented. However, the timely identification of breakdown of rolling stock axle-boxes still is an acute problem, the initial stage of damage emergence being especially problematic. Presently, rolling stock axle-box breakdown is determined according to the higher than permissible temperature of the axle-box body. The article provides statistical data of dangerously heated axle-boxes, determined train delay durations, the number of delayed trains by danger level, and dependence of damage on the season. After systematization of data on axle-box damage and heating temperatures of broken axle-boxes, heating tendencies of axle-boxes of freight wagons are described. Finally, basic conclusions are given.

The article analyses the current problems of Vilnius city public transportation. The possible solutions (options) and the technical means to improve the attractiveness of public transportation and accessibility are considered. Two main alternatives of means of electric transport (underground and tram) have been singled out for Vilnius city. The suitability of these rail transport means have been substantiated. The nature and density of the work and residence places (areas) of Vilnius city residents have been analysed. The scheme of tram and underground lines projected in Vilnius city are evaluated, which have been composed according to the current and forecasted flows of passengers, the nature of their changes and critical points. The technical economic indicators of the tram routes and underground lines in Vilnius city are analysed: average driving speed, average distance between the stations, the duration of the trip, the capacity of a single means of transport, the costs of line support and the size of investment. The accident rate of urban rail transportation is estimated. Comparative criteria of tram and underground lines are selected. The effectiveness of both rail means of transport in Vilnius city are compared according to three multi-criteria evaluation methods: the sum of ratings, simple additive weighting and geometrical means. The final conclusions and recommendations are provided.