Railway Condition Research Articles

Railway condition information modelling in a BIM framework for maintenance applications

ABSTRACT Railway maintenance management involves various interventions that, considering safety and use needs, require an integrated approach for supporting decisions. Defining an infrastructure digital twin can represent an efficient basis to implement management processes. BIM, offering a simplified and realistic digitalized model, may ensure immediate benefits for asset administrators in maintenance management and planning. It would permit to properly maintain full control of infrastructure degradation, to optimize investments and ensure adequate quality levels. In this context, a preliminary procedural framework for modelling railway condition information in an I-BIM environment is proposed, using specific survey data acquired by scheduled diagnostic trains. The authors developed customized routines and scripts to elaborate rail track geometry attributes (with real-time checks of the dynamic effects on the track) and simplify asset quality evaluation for the administrators. This may suggest a novel vision and framework to support maintenance management procedures in future developments of the overall approach.

Development of a rating model for assessing the condition of steel railway bridges

Steel railway bridges play a crucial role in global transportation networks, yet their operational lifespan is often compromised by factors such as corrosion, aging, exposure conditions, and environmental challenges. Structural Health Monitoring (SHM) systems are widely employed to extend the longevity of these bridges. However, existing SHM models typically have limitations, as they tend to focus on a limited set of parameters, and their reliance on qualitative definitions introduces subjectivity into the evaluation process. To address these shortcomings, this research aims to develop an innovative priority weight-based condition rating model. Casual Factors (CF), laboratory and Non-Destructive Tests (NDT), Visual Inspection (VI), Environmental Conditions (EC), and Type of Element (TOE), were identified as main parameters to the condition assessment. Then, the research gathered opinions from 100 experts to establish the importance of these parameters. By averaging expert opinions and ensuring a high level of consistency (i.e. below 10%), the study aimed to minimize subjectivity. Numerical definitions were introduced to the model to enhance objectivity. The Fuzzy Analytical Hierarchy Process (FAHP) was employed to calculate appropriate weightings for the identified parameters, resulting in a comprehensive equation that encapsulates the main factors influencing the condition of steel railway bridges.To validate the developed rating model, a case study was conducted, analyzing seventeen railway bridges located in various regions of Sri Lanka. Notably, the model takes into account physical, geographical, and environmental conditions, making it applicable to diverse locations worldwide. This innovative approach contributes to the enhancement of steel railway bridge maintenance strategies, promoting their sustained and reliable operation on a global scale.

Influence of vibration on sub-ballast layer induced by loading application on a fouled track ballast

The railway track’s sub-ballast layer is important, but it is often neglected, leading to the contamination and blockage of voids, as well as track deformation and degradation. These issues occur when fouling materials infiltrate the subballast due to load-induced vibration. The purposes of this paper are to investigate the influence of vibration on the sub-ballast layer when loads are applied to a fouled ballast and to determine whether sub-ballast saturation should be ignored. A ballast box was fabricated to represent actual railway conditions and filled with 100 kg of ballast aggregates containing fouling materials (crushed ballast, sand, clay, and coal) proportional to the ballast weight. In addition, a vibratory compactor plate machine was used to simulate load on the fouled ballast, inducing vibrations that caused fouling materials to migrate into the sub-ballast. The results indicate that 18% of crushed ballast, 20% of sand, 20.7% of clay, and 15% of coal infiltrated the sub-ballast due to loading-induced vibration, and fouling infiltration percentages rose as vibration from loading increased. These percentages exceeded the standard 10% weight of fouling infiltration into the sub-ballast, indicating an unfavourable subballast condition and showing that sub-ballast saturation should not be ignored. These findings have significant implications for maintenance engineers, as they underscore the need for continuous monitoring and upkeep to ensure optimal sub- ballast performance.

New working equipment of PXP 2.0 high-performance railway train

The article presents design and technical solutions for the new working equipment of the high-performance rail grinding train PXP 2.0 for the implementation of high-speed rail grinding technology in railway conditions. A description of the design of grinding carts is given, including the drive of the grinding wheels and the mechanism for setting the angle of attack of the grinding wheel. In addition, the article discusses the conditions for moving working equipment along a rail track at high speeds. The presented solutions make it possible to carry out rail grinding work at speeds of up to 30 km/h without reducing the amount of metal removal, which ensures an increase in work productivity by more than 3 times compared to existing analogues of rail grinding trains.

Innovative Trends in the Field of Railway Transport and Infrastructure in the Conditions of Railways of the Slovak Republic

Railway transport in Slovakia has the second highest share of freight and passenger transport. However, Slovak railway transport is behind in the implementation of modern approaches and technologies. The railway infrastructure in Slovakia faces several tasks related to the modernization of communication systems, automatization of railway infrastructure, and implementation of a high-speed line. Railways of the Slovak Republic (ŽSR) is a state-owned enterprise managing the railway infrastructure in Slovakia owned by the state. The paper aims to point out the technological gaps in Slovak railways and to outline innovative trends in railway transport and infrastructure in the company - Railways of the Slovak Republic.

Innovative Trends in Railway Condition Monitoring

Provision of functional safety of a railway track requires complementing the existing system of assessment of the railway track condition with the stress-strain behaviour assessment of the rail substructure, i.e. the assessment of the effect of track structure elasticity on the change of its geometric parameters during rolling stock passage over time. There is a lack of available theoretical and practical information about any pivotal changes in this field of science. The subject of the study is the in-situ elasticity indicators of a railway track and geometric monitoring indicators of railway structure condition or similar indicators obtained by numerical processing of data provided by the measuring systems of a track recording car and enabling the determination of change of irregularity parameters over time taking into account of the tonnage passed. The outcome of the investigation is the proposed approach to the development of an unparalleled diagnostic loading system which has been the missing part of the “puzzle” in the existing system of integrated assessment of the technical condition of a railway track.

Analysis of Current State of Alternative Propulsion in a Sector of Passenger Railway Transport

Abstract Green railway transport (RT) is not always a completely green transport solution, as there are still many nonelectrified or partially electrified lines in operation with polluting engine traction. Although electric rail is the most environmentally friendly, electrification of lines is a time-consuming and costly project, especially on less busy lines where electrification would be inefficient and unprofitable. Even though electric railway is the most environmentally friendly solution, electrification of lines is a time-consuming and expensive project, especially on less frequented lines where electrification would be inefficient and unprofitable. Alternative propulsion (AP) in RT is not only a way to reduce the operational emissions of passenger trains, but also to save energy and fuel, save time due to vehicle changes, and reduce the overall carbon footprint from transporting goods and people. The aim of this paper is to examine in detail the current state of development and availability within the AP railway industry, specifically for passenger transport needs, and to transparently present the results in a simple and clear way. In addition, the paper explores the possibility of applying the alternatively powered system to the conditions of the H0 model railway and research with this model.

Fault detection and quantitative assessment of wheel diameter difference based on ensemble adaptive tunable Q-factor wavelet transform and mixed kernel principal component analysis

Tread wear is inevitable for railway vehicles. Because of the complicated railway condition, the wear rates of the two wheels of a wheelset are usually unequal, which leads to the wheel diameter difference (WDD). The WDD shortens the service life of the wheelset and deteriorates the dynamic performance of railway vehicles. Therefore, it has long been desired to monitor and quantify the WDD condition. However, influenced by the random irregularity, the effective vibration features induced by the WDD may be completely submerged in noise. In this paper, an adaptive TQWT decomposition method is proposed for denoise and feature enhancement. In this method, a new evaluation index is constructed and used to determine parameters. The influence of the WDD on the vibration of the wheelset can be more obvious after denoised by the adaptive TQWT decomposition. Mixed kernel principal component analysis is introduced into the condition monitoring and quantitative assessment of the WDD. By calculating the Hoteling’s and SPE statistics, control charts are employed to identify and assess the WDD conditions quantitatively in conjunction with the corresponding control limits. The effectiveness of the proposed method is validated by the simulation and experimental study. For the experimental datasets, the proposed method gives the average fault detection rate (FDR), false alarm rate (FAR), false alarm rate (PA) of 92.74%, 2.23%, 97.47% for the statistic and the average FDR, FAR, PA of 96.57%, 2.60%, 97.29% for the SPE statistic. The results show that the proposed method can effectively monitor the WDD conditions.

Systematic Literature Review of Drone Utility in Railway Condition Monitoring

Systematic Literature Review of Drone Utility in Railway Condition Monitoring

Influence of braking speed on the wear property and simulation analysis of high-speed railway braking materials at low temperature

PurposeThe purpose of this paper is to study the influence of braking speed at –20 °C on the wear property of high-speed railway braking materials and the temperature also stress analyses of brake disc friction surface.Design/methodology/approachFriction brake tester was used to simulate the wear test of high-speed railway braking materials at diverse braking speeds (2,100, 2,400, 2,700 and 3,000 rad/min) at –20 °C and the stress and temperature analyses of brake disc friction surface were carried out by COMSOL.FindingsCompared with 20°C, there is initial stress of brake disc friction surface before brake starting; also, the maximum wear depth is larger at –20°C. Besides, at –20 °C, with the rising of braking speed, the graphite particles on the friction surface of brake pad significantly reduce. And scratches and cracks are formed on brake pad friction surface. Besides, the abrasive wear, adhesive wear and thermal cracks of brake disc friction surface are aggravated. Moreover, the maximal worn depth also increase. Meanwhile, the highest temperature and the maximum thermal stress of brake disc friction surface both raise. Furthermore, the temperature and thermal stress gradients at radial direction of brake disc friction surface aggrandize, which makes the thermal cracks on brake disc friction surface further exacerbated.Research limitations/implicationsIn this paper, the wear property of the high-speed railway braking materials is studied by combining experiment and simulation. However, due to the low-speed traveling of high-speed railway was mainly studied in this paper, there may be no comprehensive simulation of the real running condition of high-speed railway. At the same time, the working condition of low-temperature environment cannot be completely simulated and controlled.Practical implicationsThe research results of this paper provide a basic instruction for other researchers and also provide an important reference for relevant personnel to choose the braking speed of high-speed railway at –20 °C.Social implicationsThe research of this paper provides a brick for the study of high-speed railway braking materials and also provides some references for the safe service of trains in low-temperature environment.Originality/valueThis paper studied the wear property and carried out the simulation analysis of braking materials at –20 °C at diverse braking speed. The research findings provide an important reference for the selection of braking speed of high-speed railway at –20 °C.

Development and operation of a system for diagnosing the condition of regional railways tracks

Monitoring the condition of railway tracks effectively increases the safety of regional railways. A system that uses a compact on-board sensing device was previously developed for monitoring the track condition of regional railways. However, this system does not consider the running speed of the vehicle. In this study, we propose two new methods for diagnosing the condition of tracks considering the travelling speed of the vehicle: one based on the Mahalanobis distance and the other that uses Gaussian process regression. After conducting a test study to verify the effectiveness of the proposed methods, the results showed that both approaches can provide an accurate diagnosis when considering the influence of speed.

Монголия: внешняя торговля и развитие инфраструктуры

The paper reveals the modern specifics of the economy and plans for the development of infrastructure in Mongolia. The influence of anti-COVID restrictions on foreign trade is being studied. It is shown that the problems of export and raw material development and inland Mongolian isolation in the face of restrictions on crossing the border with China for vehicles were exacerbated by the poor development of the railway network. As a result of these restrictions, coal production and exports from Mongolia to China more than halved in 2020–2021. Together with the fall in coal prices in 2020 and the collapse in the services sector, this led to the deepest recession in the Mongolian economy since 1992. Plans for the development of international transport and energy corridors through Mongolia are being considered. Based on actual data, the insignificant role of Mongolia in the dynamically growing transit of container cargo in the direction of China–Europe–China is shown. The unsatisfactory condition of the Trans-Mongolian Railway and the absence of railways in a number of promising directions of freight flows prevent the full realization of the transit potential of Mongolian freight traffic. In connection with Russia’s reorientation of export flows to Asia, the Eastern Railway Corridor stands out as a promising corridor through Mongolia. A strategically significant initiative, which in the context of anti-Russian sanctions will seriously strengthen economic cooperation in the regional triangle Russia-Mongolia-China, is the plan to build a Soyuz-Vostok transit gas pipeline through Mongolia. This project will allow redirecting gas supplies from the West Siberian region of Russia, previously supplied to Europe, directly to the capital region of China. Mongolia is also interested in the implementation of this large-scale project, which seeks to obtain new opportunities for economic development. The implementation of these infrastructure development plans will allow Mongolia to not only take advantage of its location between Russia and China and strengthen the economic base for cooperation with them, but also, in general, lay the foundation for economic diversification and deeper integration into the global economic system.

Railway Track and Vehicle Onboard Monitoring: A Review

Railway condition monitoring is the compound of activities aimed at the detection and mitigation of faults in both tracks and vehicles. This minimizes damage and disruption, and increases the usability and benefits of railways. Trackside monitoring provides frequent data, but is costly and ineffective for large segments of track. Onboard monitoring using dedicated vehicles provides deep knowledge of the track, but is infrequent and requires allocated resources and track availability. The use of sensors onboard passenger trains overcomes these issues by acquiring signals more frequently and with relatively inexpensive devices, hence the increasing use of these devices. This review presents the current techniques applied for track and train condition monitoring techniques using onboard sensors, as well as the use of trackside sensors.

Image Classification-Based Defect Detection of Railway Tracks Using Fiber Bragg Grating Ultrasonic Sensors

Structural health monitoring (SHM) is vital to the maintenance of civil infrastructures. For rail transit systems, early defect detection of rail tracks can effectively prevent the occurrence of severe accidents like derailment. Non-destructive testing (NDT) has been implemented in railway online and offline monitoring systems using state-of-the-art sensing technologies. Data-driven methodologies, especially machine learning, have contributed significantly to modern NDT approaches. In this paper, an efficient and robust image classification model is proposed to achieve railway status identification using ultrasonic guided waves (UGWs). Experimental studies are conducted using a hybrid sensing system consisting of a lead–zirconate–titanate (PZT) actuator and fiber Bragg grating (FBG) sensors. Comparative studies have been firstly carried out to evaluate the performance of the UGW signals obtained by FBG sensors and high-resolution acoustic emission (AE) sensors. Three different rail web conditions are considered in this research, where the rail is: (1) intact without any defect; (2) damaged with an artificial crack; and (3) damaged with a bump on the surface made of blu-tack adhesives. The signals acquired by FBG sensors and AE sensors are compared in time and frequency domains. Then the research focuses on damage detection using a convolutional neural network (CNN) with the input of RGB spectrum images of the UGW signals acquired by FBG sensors, which are calculated using Short-time Fourier Transform (STFT). The proposed image classifier achieves high accuracy in predicting each railway condition. The visualization of the classifier indicates the high efficiency of the proposed paradigm, revealing the potential of the method to be applied to mass railway monitoring systems in the future.

Работоспособность опор контактной сети на высокоскоростных железнодорожных магистралях

Purpose: To perform working efficiency analysis of catenary separately standing reinforced-concrete supports in high-speed railway conditions, to develop measures and constructive solutions of the supports of increased reliability and durability. Methods: Analysis of typical constructive solutions according to Russia State Standard GOST 19330-99 given their exploitation experience, the use of numerical calculation methods involving calculation programs. Results: The disadvantages of being applied structures of catenary supports on railways with the use of steel and reinforced concrete are analyzed. The calculations of typical reinforced-concrete support bearing capacity and rigidity according to GOST 19330-99 with the use of SCAD computing complex for the effect of vital climatic and exploitational burdens, including ones from wind pressure at high-speed rolling stock motion trains at the speed of 300 km/h, are made. Innovative support construction has been developed which includes pillar of reinforced concrete, fiber-reinforced concrete or steel on reinforced-concrete foundation, the construction is combined with alignment-free mounting method to ensure the impermeability of construction being united parts. Practical significance: The reserves for working efficiency of typical separately-standing reinforced-concrete catenary supports in the conditions of high–speed railway trunk St. Petersburg - Moscow on project documentation basis are revealed. The possibility of pressure perception by supports from wind flow at train motion of 300 km/h speed has been established. The application of innovative combined steel-concrete structure of catenary support construction and its mounting ways are proposed. The use of support mounting and construction new way would allow to reduce support mounting laboriousness as well as to rise support reliability and durability in exploitation changing conditions.

Analytical and experimental investigation of composite pads created by using coke dust against the fading problem in railway vehicles

In this study, the effects of using coke dust in brake pad mixtures against the problem of friction coefficient reduction occurring at high temperatures in railway vehicle brake pads were investigated. For this purpose, the average friction coefficients and wear rates of the brake pads produced by using different amounts of coke dust were tested with the help of a dynamometer at different temperature values and the brake pad mixture containing coke dust with optimum ratio was determined. Brake pads with optimum coke dust ratio were tested in a train set under real railway conditions and the stopping distances of the train set and the temperatures during braking were measured. Using the stopping distances measured during railway tests and the average friction coefficients of the brake pads were analyzed analytically and compared with the dynamometer results. As a result of these tests, it has been observed that the coke dust material reduces the friction coefficient at low temperatures, but increases the friction coefficient at high temperatures and significantly reduces the amount of wear.

A Visual Method of Measuring Railway-Track Weed Infestation Level

This paper concerns the assessment of railway track surface conditions in relation to the degree of weed infestation. The paper conceptually describes the proposed method using a visual system to analyse weed infestation level. The use of image analysis software for weed detection is also proposed. This new measurement method allows for a mobile assessment of the track’s weed infestation status. Validation of the assessment method in real conditions will allow for further expansion of the system using new shades of green from the RAL palette, and will take into account a more extensive and detailed assessment of weed infestation on the track in accordance with applicable railway regulations.

Development and operation of track condition monitoring system using in-service train

Monitoring the condition of railway tracks effectively increases the safety of railways. A system that uses a compact on-board sensing device was previously developed for monitoring the track condition of railways. The system's position identification method uses GPS map-matching.However, this system had an error of several tens of meters depending on GPS reception conditions. In this study, the position correction method was tested using curvature calculated from yaw angular acceleration. The results of the test study indicated that it is possible to diagnose the location of track irregularities more clearly.

Development of an approach to creation of an automated control system for the rail grinding process

At all times, a properly organized railway network has served as a guarantor of the development of other branches of the state. In the Russian Federation, freight and passenger turnover on rail transport are increasing every year. Therefore, it is necessary to adapt to modern realities and direct efforts and finances to modernize the system for the maintenance and repair of infrastructure facilities. During the operation of the railway track, various rail defects inevitably arise (metal staining, internal longitudinal and transverse cracks, wear of the transverse and longitudinal profile, etc.). In order to eliminate such defects, the rail grinding technology is used. JSC «Russian Railways» use a Unified Corporate Automated Infrastructure Management System (UCAIMS) for accounting and analysis of infrastructure facilities. Unfortunately, UCAIMS does not have the functionality for solving such narrow-focused tasks as organizing and planning the rail grinding process. As a solution to the current problem, it is proposed to develop an automated rail grinding control system (ARGCS), which will be integrated into UCAIMS. Based on the results of the theoretical study, an approach to the creation of an automated rail grinding control system (ARGCS) with the possibility of integration into UCAIMS is proposed. The purpose of ARGCS should be in making high-quality and timely technical and economic decisions during planning work on grinding rails in the railway track conditions. The system will be based on a fundamentally new approach that enables performing timely grinding of rails with minimum costs and ensuring an increase in the efficiency of operation, maintenance and repair of the railway track. The stated requirements are planned to be achieved using a new work planning procedures. For this purpose, a dynamic programming model has been developed. For its functioning, the values of defects are divided into three degrees of importance, transition probability matrices are compiled, defects are ranked, as well as an algorithm for choosing the priority of the rail grinding site.

Optimal Inspection Scheduling Model for Monitoring Railway Track Grids

The optimization of railway track inspection schedules is of great significance for the monitoring of railway track conditions and reasonable organization of track maintenance tasks. Here, an optimal inspection scheduling model for monitoring railway tracks is proposed. Railway track inspection activities are divided into equal‐length units in the time and spatial location dimensions. The various constraints and objectives on the time and location of different track inspection activities are defined in detail regarding subdivisions of individual management units. The objectives of the model development are to achieve a more optimized equilibrium and robustness of the track inspection schedule. Based on the maximum entropy criterion, entropy is used to measure the distribution equilibrium of the inspection schedule in the time dimension. The proposed model is verified using actual data from the Lanxin railway.