Jacek Kukulski

The main task of a railway undertaking is to transport passengers and/or freight safely and cost-effectively. This task is enabled by the use of energy carriers. Since most of the rolling stock operated by major railway undertakings is electric, an additional area of activity involves managing electricity consumption and supply processes. Every business activity entails risk, including energy-related operations. The aim of this paper is to develop a method for assessing the risks associated with a railway undertaking from an electrical perspective and, based on this method, to perform such an assessment. As part of the research, a universal risk assessment approach based on the M_o_R^® (Management of Risk) methodology was developed. Risk identification was performed using the risk description principle, followed by risk estimation. The study proposes national-level variables and a procedure for determining them using publicly available data. Risk assessment and process evaluation were carried out using Monte Carlo simulation as a probabilistic tool for uncertainty propagation. As a result, the potential losses and gains that a railway undertaking may experience from an electrical perspective were estimated for scenarios in which the identified risks materialize.

The article presents research problems related to the operation of classical switch heating solutions and systems. This is due, among other things, to the excessive use of electricity and the strive to optimize these solutions. An overview of research related to various electric switch heating (ESH) systems is presented extensively in Chapter 2. This article presents selected results of thermal imaging measurements of ESH electric switch heating components used to heat railroad switches under the BRIK2/0036/2022 project. The study was carried out for different types of ordinary railroad switches most commonly used on the PKP PLK network. The studies included various positions of the switches in the normal position (straight track) and the non-normal position (switch track). The tests were conducted on real objects and under conditions allowing for the snowing of critical elements of the switch. The use of thermal imaging cameras and classic thermoelectric sensors with a recorder allowed for the assessment of the effectiveness of existing switch heating systems as well as proposed modifications. The results of the study made it possible to observe the temperature distribution for different switch design solutions and switch heating systems, and to interpret the results. Based on the obtained results, it can be concluded that the new solution in the area of electric switch heating with dedicated radiation overlays is more efficient compared to the classic solution. The use of thermal imaging cameras in research has enabled the execution and recording of heating sequences of the switch and imaging in the visible spectrum of the electromagnetic spectrum for snow melting in critical areas, such as the switch zones. Further work will focus on preparing a diagnostic manual for services responsible for the maintenance of railway switches, including the use of thermal imaging diagnostics. Subsequently, the authors will prepare the assumptions and criteria for the development of an application to assist in the interpretation of thermograms, which can be a tool supporting the diagnostics of electric switch heating (ESH) devices. The creation of a simple diagnostic tool that allows for the assessment and facilitates the interpretation of the obtained thermogram may enable maintenance services to make appropriate decisions regarding the operation of ESH systems.

The study presents original research focused on improving the reliability and energy efficiency of electric railway turnout heating systems under severe winter conditions. An innovative diagnostic methodology using high-resolution infrared thermography was developed and applied to evaluate heating uniformity and technical performance within the Polish railway infrastructure. Field investigations were carried out on operational turnouts at Gdańsk Osowa and Międzylesie stations, covering both conventional EOR systems and the advanced ESAR system. The results demonstrated that the ESAR system effectively prevented ice and snow accumulation while enabling up to a 30% reduction in active power supplied to heating elements, resulting in annual energy savings of approximately 750 kWh per turnout (29% compared with the reference system). Incorporating radiative overlays in ESAR allowed lower average surface temperatures and improved heat distribution efficiency. Temperature and energy indicators confirmed significantly higher performance of ESAR, with annual CO₂ emissions reduced by 447.75 kg and air pollutants (SO_x, NO_x, CO, particulates) by around 30%. The proposed thermographic approach proved to be a non-invasive and efficient diagnostic tool, supporting adaptive control, enhanced operational reliability, and reduced environmental impact of turnout heating systems.

In this study the rail wear influence on safety of rail vehicle motion is assessed. The profile measurements for the nominal rail head and for the slightly worn and heavily worn rail heads were performed. Then, these measured real values were entered into a computer program designed to study the motion (dynamics) of rail vehicles. The studied model of passenger vehicle moved in simulations along a track consisting of straight and curved sections with transition curve between them at two velocities. After obtaining the simulation results, they were compared for different stages of the rail wear process based on profile measurement results and the suitability of the track was assessed, too. The aim of present paper was to show that extension of the traditional approach with the simulation studies of vehicle motion and dynamics leads to different and much more precise information about the need of the rails replacement. The proposed idea and approach in the current work is original and not used in practice by the track infrastructure operators.

This paper presents the concept of a modified 60E1 rail dedicated to continuous welded rail (CWR) track. The presented solution is the subject of a patent application by the authors of the publication. The paper describes problems associated with the operation of CWR track and the phenomena of so-called “rail stressing”, i.e., stresses created in the rail due to thermal shrinkage that, in extreme cases, can lead to the buckling of the rail track. Simulation calculations of longitudinal track loads to represent the occurrence of thermal force as a result of the occurrence of high air temperatures were carried out for the constructed conventional model of the railroad track as well as the track with the proposed solutions. A discussion of the simulation results is presented, indicating the possibility for the wider application of both varieties of modified rail.

The article presents selected results of thermovision measurements of EOR elements used for heating railway turnouts under the BRIK2/0036/2022 project. The tests were carried out for various types of railway turnouts (ordinary). The results made it possible to observe the temperature distribution...

The effectiveness of railway brakes strongly depends on their thermal condition. A computer simulation and experimental investigations on a full-scale dynamometric stand were chosen as an adequate analysis of the heat transfer process in brakes. The article introduces a two-dimensional, axisymmetric numerical model of the tested disc brake. Boundary conditions related to the heat generated in the friction brake and heat transferred to the environment are also presented. The transient heat transfer problem was solved using the in-house computer program of the finite element method. The article presents simulations and experimental investigations of the intensive braking of a train with an initial high speed. Temperature responses of the disc brake on the friction surface and at other selected points are shown. In addition, a thermal imaging camera was used to assess the temperature distribution on the friction surface of the disc. The results of experimental and simulation tests were preliminarily compared. Similar maximum temperature values were obtained at the end of braking with a particular discrepancy in temperature responses during the analyzed process.

Efficient transport solutions are based on multimodal systems, with the dominant role of rail and road transport in land versions of the systems and the connecting and directing part of intermodal terminals, transhipment terminals or warehouse centres. The implementation of transport processes is always associated with the risk of lack of timeliness (quality) or threats to people, equipment and cargo (safety) resulting from human, technical, organizational and global factors like pandemics or war. The article contains a risk mapping method in multimodal transport systems configured to estimate the risk of lowering the quality of logistics services (on-time deliveries, etc.). The method combines factors usually considered separately in studies on individual modes of transport. A formal notation of risk factors as a mathematical model was proposed, and a case study was provided to picture the implementation.

The effectiveness of railway brakes is highly dependent on the thermal condition of the brake disc and friction linings. An effective research method for the heat transfer process in brakes was computer simulation and experimental tests on a full-size dynamometric test bench. A two-dimensional, axially symmetric numerical model of transient thermal conductivity in a railway brake was presented. Appropriate boundary conditions of the problem were applied, describing the heat generated in the brake and discharged to the environment. The problem was solved using the finite-element method. This article presents exemplary results of the brake temperature calculations obtained using the numerical model and the results of experimental tests carried out on two types of brake discs.

Work was carried out to diagnose irregularities in the operation of a vacuum-tube solar collector. Experimental investigations of the collector were carried out at the solar collector field test stand in the Laboratory of Solar Collectors at the Koszalin University of Technology. The scope of the work included the following: research on thermal efficiency characteristics, research on the temperature distribution on the solar collector manifold, and research on the geometric structure of the heat pipe and filling with the working medium. Based on the diagnostic tests carried out, the occurrence of incorrect sedimentation in the condenser on the neck of the heat pipe (44%) and an incorrect amount of working medium (66%) were found. The results show that the functioning of the heat pipe significantly depends on its geometric structure and the amount of working medium. Any irregularity at the production stage contributes to a reduction in the thermal efficiency of the solar collector. The results of the experimental research presented in this paper can be used in the diagnostic analyses of solar systems as well as in the organisation of the manufacturing processes of these systems.