RAILWAYS IN LITHUANIA: FROM TSARIST RUSSIA TO RAIL BALTICA

Lithuania is a transit country. It is a small but significant territory between East and West. This fact is substantiated by the history of the country railways, which started when Tsarist Russia launched the construction of the railway between Saint-Petersburg and Warsaw. There is not much research into the history of railways in Russia, also in Lithuania. Besides, not all available information is reliable due to the nihilistic attitudes towards Tsarism of that time. Only some of the railways in the former Soviet Union were written and talked about. The history of the Lithuania railway is not an exception. Different written sources provide a variety of dates for the first railway to be built in Lithuania. They mirror varied events in the history of Lithuanian railways, thus all of them must be taken into consideration. The article presents the evolution of Lithuanian railway transport from Tsarist Russia to Rail Baltica, which is the European railway project currently implemented in Lithuania. The article discusses the world’s first railways including the ones in Tsarist Russia when the history of Lithuanian railways started. The article also considers the building of the first railway in Lithuania, construction of railway stations, setting the transportation tariffs, selection of railway employees. The author of the article employs historical and online resources as well as a long-standing personal experience in railway transport. The research into Tsar Family’s diaries and historical novels makes it possible to disclose the facts that are not widely known. The author considers the future of Lithuania with reference to the construction of the European railway Rail Baltica. The article would be useful for the readers who are interested in the historical development and future of Lithuanian railways.

Optical diagnostics of railway rail defects

The safety of rail transport, including passenger traffic, largely depends on the timely diagnosis of the state of the rail infrastructure. To determine the state of metal structures, the method of acoustic emission (AE) is used. It is based on the registration of elastic mechanical vibrations arising in the material of the controlled object from a defect. The AE method is highly informative, but the interpretation of measurement results often causes difficulties, especially when studying complex structural elements. In this paper, it is proposed to use the digital image correlation (DIC) method to study the defects of railway rails using the acoustic emission method. Visualization of defects using the DIC method will make it possible to better interpret the results of inspection by the acoustic emission method and to establish the relationship between the size of defects and the parameters of AE pulses.

Railway Rail Material Quality Tests

The article presents the obligatory qualitative tests of the material of railway rails, performed for the railway industry and having the status of qualifying tests, to which railway rails are subjected. They include tests of fracture mechanics (determination of the critical stress intensity factor KIC, determination of the fatigue crack development velocity da / dN), determination of stresses in rail feet and fatigue tests. The article presents the results of tests of standard-gauge rails type 60E1, rolled from R260 steel by selected European producers, and an analysis of the results was carried out based on the guidelines of the PN-EN 13674-1 + A1: 2017-07 standard. Keywords: quality tests of rails, KIC coefficient, propagation da/dN, stress

Measurements of railway welded rail joints with a laser device

One of the methods of joining rails is welding with termite, which guarantees a secure and stable connection of two sections of the rail without the need to use additional connecting elements and supporting the welded place. After joining (making a weld), appropriate mechanical processing of the joint is required in order to obtain the given rail head profile. The quality and diligence of the connection made has a major impact on safety, noise emission during the journey (wheel rolling) and the comfort of travelers. This article describes selected methods of making railway rail joints and presents the results of measurements with a portable laser measuring device Calipri C40 of the rail head within the welded rail joint made by thermite welding. An attempt to use this device for measurements of welded rail joints is shown, advantages and disadvantages as well as conclusions from the performed measurements are described.

Rail/wheel rolling noise generation due to parametric excitation

When a wheel rolls over a railway rail, it ‘sees’ a varying stiffness downwards because the rail is periodically supported by sleepers, leading to parametric excitation of the rail/wheel system. This study investigates the importance of parametric excitation on railway noise generation. Because the problem is non-stationary, it is modelled in the time domain. Rail and wheel impulse response functions, together with an iteration scheme to match boundary conditions in the rail/wheel contact patch, yield rail and wheel response plus contact force at each wheel position on the rail. Forward velocity and rotation of the elastic wheel are accounted for. Feedback coupling between response and force takes part in the excitation. Numerical simulations show that, for a rail on stiff pads, parametric excitation is a major excitation mechanism, above all leading to increased excitation and noise levels in a broad frequency region around the pinned–pinned frequency.

THE INFLUENCE OF THE SHAPE OF WORKING SURFACE OF STRAIGHTENING ROLLERS OF VERTICAL AND HORIZONTAL STRAIGHTENING MACHINES ON THE STATE OF RESIDUAL STRESSES IN RAILWAY RAIL – SECOND STAGE OF RESEARCHES

The paper presents the results of the second stage of work on the influence of the shape of straightening rollers on the state of residual stresses in rails, conducted as part of a project co-financed by the National Centre for Research and Development. The tests included numerical simulations of the rail straightening process using a new roll pass design of vertical and horizontal straightener rollers, determination of stress distribution maps in the rail after straightening in successive rollers of both straightening machines, as well as measurement of residual stresses in the rails after straightening operation in industrial conditions. The tests were carried out on R260 grade 60E1 rails. The reduction of tensile residual stresses in the centre of symmetry axis of the rail foot was obtained up to an average level of 32 MPa, i.e. by more than four times less in relation to the level achieved using traditional technology.