Railway Infrastructure Research Articles

Innovative technologies of rail transport used by the Armed Forces of the Republic of Poland

Innovation in rail transport has a wide range of applications, which includes customer contact, train moni-toring with modern internet-connected sensors and data analysis, as well as the use of artificial intelli-gence for route optimization, customer service management and vehicle maintenance. The presented is-sues constitute a research niche in the field of the use of innovations in military rail transport, which en-courages research in this area. The article describes innovative technologies of rail transport used by the Armed Forces of the Republic of Poland. The subject of the research included in the article are the latest innovations in the field of rail transport technology and the analysis of their benefits and potential use by the Polish Armed Forces. These include: intelligent control systems, infrastructure maintenance, innova-tive designs of trains and wagons. The aim of the article is to identify the advantages of innovative tech-nologies and their potential application in the Polish Armed Forces. In order to achieve the objectives of the article outlined in this way, it is necessary to answer the following research questions: What innovative technologies of rail transport are used by the Polish Armed Forces? What are the prospects for the devel-opment of innovative rail transport technologies for defence purposes in Poland? What innovative solu-tions concerning the railway infrastructure in Poland could improve the safety of movements of troops by rail? The research hypothesis was adopted in the article: Innovative solutions in rail transport used by the Polish Armed Forces will effectively support the implementation of transports in the movement and transport subsystem (M&T). In order to verify the hypothesis, the following research methods were used: theoretical methods (analysis, synthesis, abstraction, inference, generalization) and the method of expert interview with representatives of the movement and transport subsystem. The presented approach allowed to analyse the problem from different perspectives, which makes it possible to conduct detailed research on this important and current issue.

Optical Measurement System for Monitoring Railway Infrastructure—A Review

Rail infrastructure plays an important role in fulfilling the demand for freight and passenger transportation. Increases in traffic volume, heavier axles and vehicles, higher speeds, and increasing climate extremes all contribute to the constant strain on the infrastructure. Due to their major importance in the transportation of people and freight, they are subject to continuous condition monitoring. This is an essential requirement for the selective planning of maintenance tasks and ultimately for safe and reliable operation. Various measuring systems have been developed for this purpose. These must measure precisely, quickly, and robustly under difficult conditions. Whether installed from mobile or stationary platforms, they have to cope with a wide range of ambient temperatures and lighting conditions, harsh environmental influences, and varying degrees of reflection. Despite these circumstances, railway operators require precise measurement data, high data densities even at high traveling speeds, and a user-friendly presentation of the results. Photogrammetry, laser scanning, and fiber optics are light-based measurement methods that are used in this sector. They are able to record with high precision rail infrastructure such as overhead contact systems, clearance profiles, rail tracks, and much more. This article provides an overview of the established and modern optical sensing methods, as well as the use of artificial intelligence as an evaluation method, and highlights their advantages and disadvantages.

MODERN TRENDS AND INNOVATIONS IN THE MODERNIZATION OF RAILWAY LINES BASED ON EXPERIENCE IN THE REPUBLIC OF BULGARIA

The modernization of the Bulgarian railways has been underway for over 20 years. Hundreds of kilometres have been rehabilitated with funds from the European Union. The aim is to join the main Trans-European network, according to Regulation No. 1315/2013 [1] of the EU. Given the complex mountainous relief, the specific engineering objects are now the design and construction of a large number of tunnels (in the Sofia-Plovdiv section alone, over 16 tunnels are planned, the longest of which is 6 km long); the design and construction of railway bridges, some of which have unique dimensions; the rehabilitation of bridges; and the construction of drainage facilities, including drains, ditches, and culverts (some of the culverts have a unique length of about 80 m). The report analyses the main railway projects with a critical analysis of strengths and weaknesses, according to the EU cost-benefit analysis methodology. The analysis presented in this report is unique for Bulgarian railways, as it includes a large volume of projects in the field of designing and building railway infrastructure according to European and world rules, which have not been used in Bulgaria until now. This is only the first stage of scientific research, which involves collecting data, examining the data, and building a working hypothesis. After the completion of the construction (supposedly by around 2029), there will be measurements of the railway and a diagnosis of its condition. At this time, data will be collected again, and the credibility of the presented hypotheses will be verified. The conclusions will serve for the more adequate preparation of the technical assignments for future infrastructure projects in the field of railways.

ASSESSING THE POTENTIAL OF RAILWAYS TO REDUCE CO2 EMISSIONS: A COINTEGRATION STUDY OF ESTONIA'S TRANSPORT SECTOR

This The transportation sector is a major contributor to CO2 emissions, playing a significant role in exacerbating climate change. Railways, known for their greater energy efficiency compared to other modes of transport, present a viable solution for mitigating emissions, particularly in countries like Estonia. In 2014, transport-related CO2 emissions in Estonia were recorded at 12.7%, marking an overall upward trend since 1995, despite experiencing some fluctuations over the years. This study aims to explore the long-term equilibrium relationship between CO2 emissions from transport and railway passenger kilometers in Estonia through the application of cointegration analysis. Utilizing Engle-Granger and Phillips-Ouliaris cointegration tests, the analysis reveals a stable, long-term equilibrium relationship between the two variables. The findings suggest that an increase in railway passenger kilometers could potentially lead to a reduction in CO2 emissions from transport. These results underscore the importance of enhancing railway infrastructure and usage as a strategic measure to curb transportation-related emissions and contribute to environmental sustainability.

Design and Construction of Automatic Railway Crossing Gate Control Using Proximity and Infrared Sensors Based on Omron CP1E E30-SDRA PLC

Railway crossing gates are one of the railway infrastructure facilities. Currently, there are still many problems, especially in traffic accidents. The cause of traffic accidents at railway crossings generally occurs due to the lack of facilities and infrastructure (rail crossing gates) and negligence of guards in carrying out their duties. Therefore, it is necessary to design an automatic railway crossing gate. The prototype of the automatic railway crossing controller uses proximity and infrared sensors to detect the arrival and departure of trains. When the infrared or proximity sensor detects the arrival of a train, the Programmable Logic Controller (PLC) activates Pulse Width Modulation (PWM), buzzer, and Light Emitting Diode (LED), so that the crossing motor goes down. After the crossing touches the limit switch, the motor stops and the buzzer and Light Emitting Diode (LED) remain on. The infrared or proximity sensor detects the departure of the train so that it reverses the motor so that the crossing goes up, then turns off the buzzer and Light Emitting Diode (LED). In this way, it is hoped that this design can be used to increase the efficiency of the system's operational costs and optimize the railway crossing system and is expected to reduce the number of traffic accidents at railway crossings.

Evaluating the impact of rail surface roughness post-grinding: An experimental and elastoplastic modelling approach

Grinding is regularly conducted on railway tracks to prevent crack propagation and surface deterioration. However, grinding can introduce roughness on rail surfaces, potentially leading to stress and strain concentration that increase the likelihood of crack initiation. This paper proposes the utilization of surface roughness obtained by replicating the ground rail surface to assess its impact on train wheel-rail interactions. A novel approach which integrates the replicated roughness into an elastoplastic contact model, allows for a detailed assessment of its effects on contact pressure, and residual strain and stress distributions. The findings highlight the importance of considering surface roughness in predictive maintenance planning for railway infrastructure, as it can significantly influence the structural integrity and long-term performance of the track system.

Influence of Terrain on Windblown Sand Flow Field Characteristics around Railway Culverts

Aeolian sand hazards are often a threat to culverts, which are important channels and pieces of infrastructure of the desert railway. In addition to wind speed, wind direction, and culvert structure, terrain may also be an important reason for the formation of culvert sand hazards. However, there are few studies on the effect of terrain on the sediment accumulation characteristics of culverts. This paper established computational fluid dynamics (CFD) models of railway culverts (flat and concave culverts) based on Euler’s two-fluid theory. An analysis of the influence of terrain on the distribution law of the flow fields and sand accumulation around railway culverts was carried out. The results show that the horizontal wind speed curves changes in a “W” shape along the centre axis surface from the forecourt to the rearcourt within a range of 30 m~66.8 m. Low-speed backflow is formed at the inlet and outlet of the culvert, and the minimum wind speed reaches −3.6 m/s and −4.2 m/s, respectively, when the height from the bottom of the culvert is 1.0 m and 1.5 m, resulting in intensified sand sedimentation. In concave culverts, the lower the roadbed height, the easier it is for sand to accumulate at the culvert outlet, the rearcourt, and the track; the sand volume fraction is close to 0.63, affecting the normal operation of the trains. On the contrary, the higher the roadbed, the easier it is for sand to accumulate at the culvert inlet, hindering the passage of engineering vehicles and reducing the function of the culverts. These results reveal that terrain plays a pivotal role in the sand accumulation around culverts and that it should be one of the key considerations for the design of new railway culverts. This work can provide a theoretical basis for preventing and managing sand hazards in railway culverts.

Quantifying future carbon emissions uncertainties under stochastic modeling and Monte Carlo simulation: Insights for environmental policy consideration for the Belt and Road Initiative Region

This study critically examines future carbon (CO2) emissions in the Belt & Road Initiative (BRI) region, considering factors such as energy consumption, economic growth, population growth, and population density. The objective of this study is to identify critical areas of higher emissions, which require policy intervention capable of strengthening sustainability in the BRI compact. A combined approach of stochastic modeling and Monte Carlo simulations was employed, utilizing panel data from 45 countries in the BRI region from 1990 to 2021. Results confirm that emissions are higher in all scenarios in direct proportion to electric power consumption, population growth, and Gross Domestic Product (GDP) growth. In scenarios with high emissions, a continuous and significant upward trend in CO2 emissions was observe. The medium emissions scenario exhibited a more moderated rise in emissions, suggesting a balance between economic development and environmental considerations. Critical areas for future environmental policy-making resides in electric power consumption, population growth, and GDP growth. The study strongly recommends for a shift from the current focus on road and railway infrastructure to renewable energy infrastructure, green innovations and efficient technology transfer to member countries. Without this, the BRI region is likely to face increased emissions, posing significant challenges to future sustainable development and global environmental sustainability.

Diagnosis of high‐speed railway ballastless track arching based on unsupervised learning framework

AbstractVehicle‐mounted detection methods have been widely applied in the maintenance of high‐speed railways (HSRs), providing feasibility for diagnosing ballastless track arching. However, applying detection data faces several key limitations: (1) The threshold mostly requires manual setting, making recognition accuracy highly subjective; (2) the extensive workload of manual inspections makes it challenging to label detection data, hindering the application of supervised learning approaches. To address these problems, this paper utilizes the longitudinal level irregularity data obtained from vehicle‐mounted detection, employing the concept of unsupervised learning for dimensionality reduction, combined with clustering algorithms and minimal label fine‐tuning, to design two frameworks: the fully unsupervised framework (FUF) and the few‐shot fine‐tuned framework (FFF). Experiments on dynamic detection data from a Chinese HSR line were conducted, comparing the performance of data dimensionality reduction, clustering, and classification under different strategy combinations. The results show that the improved variational autoencoder significantly enhances the performance of the encoder in dimensionality reduction, facilitating better feature extraction; the FUF achieves effective clustering outcomes without any labeled samples and its adjusted rand index score exceeded 0.8, showcasing its robustness and applicability in scenarios with no prior annotations; the FFF requires only a small number of labeled samples (labeling ratio of 5%) and achieves excellent performance, with metrics such as accuracy exceeding 0.85, thus greatly reducing the reliance on labeled data. This study offers a novel method for solving engineering issues with limited labeled data, providing an efficient solution for identifying track arching defects and advancing railway infrastructure monitoring.

Fatigue crack growth rate under mixed-mode loading conditions (I+III) of a carbide-free bainitic steel designed for rail applications

Carbide-free bainitic steel was designed for railway infrastructure application, focusing on high-speed and heavy-loaded freight tracks. Considering the complex state of stresses occurring on the rails running surface, mode III plays a significant role in the initiation and propagation of fatigue cracks of rails during service. Thus, the Fatigue Crack Growth Rate (FCGR) under mixed-mode loading conditions (I+III) was evaluated. It was revealed, that fatigue lifetime increases with loading angle modes. In the area of fatigue fracture, transgranular cracking mechanisms dominated. For the stable fatigue crack growth, a trend was observed related to the decrease in the fraction of intergranular fracture with the increasing loading angle modes (α). Secondary cracks indicated privileged cracking directions related to the crystallographic structure of bainite. The influence of the mechanical stability of retained austenite during mixed-mode FCGR requires further in-depth research. These studies contribute to understanding the factors influencing the reliability of railway tracks in terms of designing new materials and modeling the rate of crack growth to precise assessment of the life cycle of rails.

Increasing the theoretical and practical capacity of the Eastern Operating Domain by means of advanced train separation systems

Aim. Currently, the mainline railway network does not fully meet the market’s needs in terms of capacity, which is why every day JSC RZD is forced to reject 2 to 4% of applications for the transportation of goods across routes passing through limited-capacity railway infrastructure facilities. Increasing the practical capacity of railway lines by building additional tracks at stations and on open lines is unacceptably long and requires massive capital investments. Methods. It is proposed to solve the above problem by increasing the utilization of railway infrastructure by reducing the succession times and station operation times in the traffic schedule by deploying moving block and virtual coupling. This approach allows reducing capital investments up to 32 times and the duration of project implementation up to 8 times with a comparable capacity increase. The paper details the functionality of train separation technology and its technical parameters. Conclusion. The train separation technology has been deployed and is in operation on the Far Eastern, Trans-Baikal, East Siberian, and Krasnoyarsk Railways, branches of JSC RZD, that are part of the Eastern Operating Domain of JSC RZD network. By the end of 2023, the total length of track covered by the train separation solution was 5,734 km. Conclusion. In 2023, the lines of the Eastern Operating Domain handled almost 36 thousand pairs of trains with reduced spacing. The train separation technology also allows improving the safety and the level of digitalisation of the transportation process.

Investigation of Railway Network Capacity by Means of Dynamic Flows

Capacity calculations are essential for the long-term planning of railway infrastructure. Many of the methods currently used in practice calculate characteristic capacity values separately for the single elements (mainly lines and nodes) of a railway network. Approaches that consider the entire network to account for interactions between the elements often rely on many assumptions, which renders a direct practical application difficult. This paper therefore introduces a linear optimization model that comprises railway-specific constraints such as minimum headway times, line capacities, and route conflicts. Under the consideration of these constraints, the developed model permits the calculation of a network-wide capacity. The model is validated on a sample network that is based on a real network of the German railway infrastructure.

Flood Susceptibility Assessment for Improving the Resilience Capacity of Railway Infrastructure Networks

Flood Susceptibility Assessment for Improving the Resilience Capacity of Railway Infrastructure Networks

Fatigue life assessment of thermite welded rails based on laboratory tests and field measurement data

This in-depth study assesses the fatigue life of thermite-welded 60E1 rails by combining fatigue experimental tests with field measurement data. Material characterization, conducted using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM), aimed to understand the fatigue behavior of these materials. The research was particularly focused on high-speed rail lines in South Korea, targeting areas with influence of track condition to collect strain data. By combining dynamic modulus calculations from high-speed tensile tests with the rain flow counting method for determining wheel loads, and employing the Linear Cumulative Damage method for estimating rail fatigue life, this study provides novel insights into the maintenance and durability of thermite welded rails. The integration of detailed laboratory experiments with field stress data offers a significant contribution to the predictive maintenance and lifecycle management of high-speed railway infrastructure.

Railway Infrastructure Management: Selection of Overhead Contact Line Ampacity Considering Operational and Design Factors

This paper presents a novel approach to determining the ampacity of DC and AC railway overhead contact lines, considering both operational and design factors. The ampacity of contact lines is influenced by several design parameters, including materials, cross section and the number of catenary and contact wires, etc. Additionally, the permissible long-term and short-term current values, which correspond to the permissible temperatures defined by EN 50119:2020, are affected by operational factors such as ambient temperature, solar radiation, heat exchange conditions, wind speed, wear of contact wires. Existing methods for determining the ampacity of overhead contact lines often fail to account adequately for these critical factors and lack the necessary procedures to calculate the 30 min ampacity required by EN 50119:2020. In response, the method proposed in this study adapts the procedures of IEEE 738-2012 to the specific needs of railway contact lines, taking into account the effect of contact wire wear on current distribution and overall ampacity. The proposed method offers a more realistic and practical approach to determining the ampacity of contact lines, thereby enhancing the reliability and efficiency of the traction power supply infrastructure. This method could be useful for railway infrastructure managers to ensure the safe and efficient operation under varying environmental and operational conditions.

Assessment of Economic Damage from Natural Hazards to the Railway Infrastructure of the Russian Federation

Assessment of Economic Damage from Natural Hazards to the Railway Infrastructure of the Russian Federation

철도산업과 기후변화대응

The railroad industry is the best means of transportation to respond to climate change, as it is more energy efficient than the automobile and aircraft industries and emits about six times less greenhouse gases. As of 2018, the transportation sector of railroads emits 2.6% of greenhouse gases, but greenhouse gases should be reduced by converting diesel locomotives to new and renewable energy locomotives and electric locomotives. However, the Framework Act on the Railway Industry, the Railroad Safety Act, the Railroad Construction Act, and the Railroad Business Act do not have legal and institutional mechanisms to respond to climate change or adapt to the climate crisis. Review the legislation and precedents of France and the United States to seek implications for Korea. The Framework Act on the Railway Industry shall establish and implement the national freight and passenger transport sharing rate and the greenhouse gas reduction target, and shall be improved to include matters on climate change and response to the climate crisis in the national policies and basic plans. The Railway Construction Act should also monitor the effects of climate change, such as extreme heat waves, extreme cold waves, extreme strong winds (types), extreme floods, and extreme wildfires, analyze the cost-benefit analysis of adverse effects on railway infrastructure to build them in advance, and maintain them to improve the quality of railway infrastructure, and include climate change response and adaptation to the climate crisis in the railway network plan. The Railway Business Act and the Railroad Safety Act should be revised to ban the operation of diesel locomotives in stages, such as California and the United Kingdom, to raise funds for the conversion of diesel locomotives to environment-friendly locomotives, report their status to the Minister of Land, Infrastructure and Transport, and stipulate that diesel locomotives cannot be idled for more than 30 minutes. Finally, railway stations and structures should be installed with geothermal power plants and solar power plants, and certified as carbon-zero buildings.

Incentive and Supervision Mechanism for Operation and Maintenance of Mega Railway Infrastructure Based on Principal-Agent Theory

This study incorporates fairness preference theory into the principal-agent model to address the challenges arising from information asymmetry between the government and railway infrastructure operation and maintenance (O&M) companies. It develops an incentive and supervision model for the management of mega railway infrastructure operations and maintenance, considering two perspectives: full rationality and fairness preference. The models are compared and analyzed, exploring the costs of government supervision and the changes in expected benefits when equity preference is taken into account. The conclusions are supported by numerical examples and visual analysis, illustrating the impact of different variable parameters on the behavioral strategies of the government and O&M companies. The findings demonstrate that a well-designed incentive and supervision mechanism can effectively regulate the behavior of railway infrastructure O&M companies. The effort level of O&M companies is positively correlated with the intensity of government incentives and supervision. Moreover, from the perspective of fairness preference, transferring some financial benefits from the government to O&M companies not only increases their extra effort but also reduces government’s supervision costs, while the government’s expected utility gain depends on the strength of “reciprocity” exhibited by O&M companies.

Identifying climate-related failures in railway infrastructure using machine learning

Climate change impacts pose challenges to a dependable operation of railway infrastructure assets, thus necessitating understanding and mitigating its effects. This study proposes a machine learning framework to distinguish between climatic and non-climatic failures in railway infrastructure. The maintenance data of turnout assets from Sweden’s railway were collected and integrated with asset design, geographical and meteorological parameters. Various machine learning algorithms were employed to classify failures across multiple time horizons. The Random Forest model demonstrated a high accuracy of 0.827 and stable F1-scores across all time horizons. The study identified minimum-temperature and quantity of snow and rain prior to the event as the most influential factors. The 24-hour time horizon prior to failure emerged as the most effective time window for the classification. The practical implications and applications include enhancement of maintenance and renewal process, supporting more effective resource allocation, and implementing climate adaptation measures towards resilience railway infrastructure management.

Risk assessment of national railway infrastructure due to sea-level rise: an application of a methodological framework in Italian coastal railways

Nowadays, within the built environment, railway infrastructures play a key role to sustain national policies oriented toward promoting sustainable mobility. For this reason, national institutions and infrastructure managers need to increase their awareness in relation to the current and future climate risks on their representative systems. Among climate change impacts, preventing the effects of sea-level rise (SLR) on coastal railway infrastructures is a priority. The first step in the climate change adaptation policy cycle is the development of an ad hoc climate risk assessment. In this view, this research develops a vulnerability and a risk assessment metric to identify the hotspots within a national coastal railway due to the SLR impacts. The proposed methodology required different steps to quantify the SLR projections and the vulnerability characteristics of the assets, in terms of sensitivity and adaptive capacity. The investigated case study is the coastal railway infrastructure in Italy, thanks to an initial approach of co-design participative processes with the national Infrastructure Manager: Rete Ferroviaria Italiana (RFI). The results of this application, although not included in the paper due to confidential reasons imposed by the infrastructure manager — led to a clear identification of the areas and the coastal railway sections which are exposed to high levels of risks and of the places which require priority actions for urgent adaptation in a view of climate proof infrastructures.