One of the technical possibilities to solve a gauge crossing is to install a dual gauge. This solution has several advantages and disadvantages discussed in this paper. Lack of experience of maintenance and lack of standards for the design of dual track are among the most important disadvantages. The wheel and rail interface on track curves is more difficult than in straight sections. Therefore, the subject of the present article is a geometrical parameter of dual gauge track, i.e., the rail superelevation, which has an impact on the wheel–rail interaction at curves and influences the value of uncompensated acceleration, occurring when a train passes a curve, and, consequently, the intensity of rail wear. The objective of the present article is to analyse the features of dual gauge track and the superelevation calculation methodology considered, to present the approach to rational calculation of superelevation for dual gauge track of Šeštokai–Mockava (Lithuania–Poland) using several calculation versions as well as to make recommendations for the calculation of superelevation.

Railway curves have influence on train speed on a curve and/or wheel/rail interface. Additional forces that have to be compensated appear in the curves. The purpose of superelevation is to compensate acceleration emerging in the curve thus assuring comfortable passenger transportation and equal wearing of both rails. However, it is very difficult to calculate superelevation when designing and maintaining a railway track, because the estimation of actual train speed on the curves is very complicated. As we know, railway lines can be divided into conventional, high speed and heavy haul ones. As these lines are absolutely different, requirements for the installation and maintenance of the track may also differ. Conventional rail lines are the object of research discussed in this article. The speed of freight and passenger trains is different on conventional rail lines, which is an essential factor in determining superelevation. On the ground of scientific researches, the article analyzes and evaluates the factors influencing wheel/rail interface on the curves. The paper also deals with railway line curves, superelevation and uncompensated lateral acceleration. The article presents the method used in Lithuania for calculating superelevation in the railway curves and analyzes calculation defects. For research purposes, analytical and statistical methods have been used. The obtained results have shown that actual superelevation in the researched curves does not match the calculated one. The calculations and obtained results of superelevation depend on how average train speed in the curves is estimated and used for calculations. As most of the results show that even small variations in the curve have a great influence on track/vehicle behaviour, it is necessary to find more precise methods for calculating superelevation, evaluating actual train speed and considering permissible uncompensated lateral acceleration in the curves.

Under high cyclic loading of trains the particles of railway ballast disintegrate and worsen in a progressing way. Disintegration of ballast particles is always related to railway track deformations which require expensive continuous maintenance of railway track-the failed ballast is replaced by a new one and is later compacted (tampered). Railway ballast has a significant influence on the quality and strength of railway track. Therefore, it has been subjected to many specific requirements. Some of them are very important both in structural and cost-efficiency point of view, others are less important or already fully implemented (adapted). The scientists analyse and present research results comprising not only the entire railway transport system but also each of its components. Seeking to rationally plan further comprehensive research on the ballast bed and materials used in it, the article overviews and systematically discusses the arising problems associated with construction and aggregates of the ballast bed. The article gives the analysis of the functions of crushed rock ballast bed and requirements set to it. Also, studies the results of worldwide scientific researches and need for their adaption to Lithuanian operating conditions. The article presents the research on the condition of railway ballast layers (1514 km) in the railway lines of Lithuania and discusses the results. Additionally the detailed geological studies were carried out in 84 km in length of ballast bed.

Abstract. The switch is the most complicated and expensive component of a superstructure of the railway track. It requires particular attention and maintenance. The lifetime of the switch depends on its operating conditions and on a lifetime of its separate components, mostly the tongue and the frog. Defects of these two components emerge considerably earlier than that of the others. Reliable, uninterrupted and safe railway traffic depends on condition of the switch components. Condition of the switch components depends on their maintenance and determination and elimination of the defects in time. A very important task is to assure qualitative, long-lasting and cost-efficient switch appliance. In order to realize these objectives it is necessary: to improve the switch construction; to use materials that should have improved physical and mechanical characteristics for the manufacture of the switch; to improve organization and performance of the switch maintenance and repair applying modern techniques and methods. In order to determine dependence of load amount on tongue, frog and stock rail wear, analysis of technical and running conditions of replaced switches in the stations of Lithuanian railway lines in 2002, 2003 and 2005, is presented in the article. Authors' purpose is: to determine wear reasons of switch components; to examine load amount dependence on tongue, frog and stock rail wear and to submit the suggestions on improving the switch construction, installation and maintenance in order to increase the lifetime of the switch.

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