Railway Maintenance Research Articles

Experimental Analysis of Rail Contact Fatigue Damage on Frog Rail of Fixed Common Crossing 1:12

Assembled fixed common crossings of the steel grade R350HT with high switch angles are subjected to quick rail contact fatigue (RCF) deterioration. The crossings are a significant cost driver in railway maintenance and have an important influence on reliability and availability in railway transportation. The present paper is devoted to the experimental study of the deterioration causes that is based on inertial and geometrical measurements on one crossing during its full lifecycle. The causes are classified into primary technical ones and secondary ones, which depend on the operational work and maintenance of track and rolling stock. The primary causes are studied using analyses of the impact position and inertial measurements on the frog nose during the crossing lifecycle, the end of which is marked by RCF defects. An application of the machine learning technique t-distributed stochastic neighbor embedding (t-SNE) allowed to determine a small cluster of high-impact loadings that correspond to the future damage zone location. The appearance of the high-impact loadings group on a certain location is explained by the secondary causes: rail and wheel wear and wheel lateral position. A multivariate kinematic modeling of wheel passages from wing to frog rail provided the wheel trajectories, impact position, and trajectory kink angle in the impact point. The distribution of the calculated impact angles along the frog rail demonstrated the presence of a small cluster of high-impact angles outside of the zone subjected to the highest number of impacts. The results of the geometrical measurements correspond to those obtained by the acceleration measurements.

High-speed Railway Fastener Detection Using Minima Significant Region and Local Binary Patterns

Railway fastener is an important part of the railway system. Keeping the fasteners effective is essential to ensure the safe operation of the railway, so abnormal railway fastener detection is a main task of railway maintenance. With the development of railway system, the traditional manual fastener detection method has been unable to meet the application requirements, because it is very slow, costly, and dangerous. In this paper, we propose a novel method for abnormal fastener detection based on computer vision, which can detect missing fasteners automatically. In this method, Minima Significant Region is extracted in order to improve the fastener localization accuracy. Then, fastener recognition is operated using local binary features and Support Vector Machine classifier based on the fastener sub-images which are obtained by fastener localization. The proposed method is evaluated in our own database which is obtained by railway inspection system in different environments. The experimental results have shown improved performance against the state-of-the-art algorithm.

Importance and Applications of Robotic and Autonomous Systems (RAS) in Railway Maintenance Sector: A Review

Maintenance, which is critical for safe, reliable, quality, and cost-effective service, plays a dominant role in the railway industry. Therefore, this paper examines the importance and applications of Robotic and Autonomous Systems (RAS) in railway maintenance. More than 70 research publications, which are either in practice or under investigation describing RAS developments in the railway maintenance, are analysed. It has been found that the majority of RAS developed are for rolling-stock maintenance, followed by railway track maintenance. Further, it has been found that there is growing interest and demand for robotics and autonomous systems in the railway maintenance sector, which is largely due to the increased competition, rapid expansion and ever-increasing expenses.

Understanding the capabilities of GPR for the measurement of ballast fouling conditions

Ground penetrating radar (GPR) has become a widely used trackbed inspection tool for railroad maintenance engineers. The method is attractive, due to the ability to autonomously collect continuous trackbed quality related information at traffic speeds (20–200 km/h). Information on ballast quality, formation settlement and the presence of saturated materials is used to plan maintenance and budget material replacement.Ballast fouling levels and moisture content are key properties of ballast quality that affect the stiffness of the trackbed. Due to the often highly heterogeneous composition of trackbed materials, extracting related information from GPR data alone is challenging.This paper considers in detail how electromagnetic properties of trackbed materials, relating to varying degrees of ballast fouling and moisture content, affect attributes derived from reflected and scattered GPR signals. It is shown that the inherent ambiguities in the response of GPR to fouling and moisture within the trackbed mean that neither can be uniquely determined by the method. We present the less ambiguous measure of the thickness of clean ballast, a useful proxy for the overall fouling condition of the trackbed.

Smart and Sustainable eMaintenance: Capabilities for Digitalization of Maintenance

In the era of Industry 4.0, researchers have begun to more thoroughly examine digital maintenance, i.e., eMaintenance, as digitization is increasingly affecting today’s society. This area is particularly interesting in the case of long-life components such as those used in the mining and transport industries. With eMaintenance, the correct type of maintenance can be utilized and the frequency for device maintenance can be reduced through real-time diagnosis. This leads to reduced costs for companies that implement eMaintenance as well as environmental benefits through improved resource utilization. Advantages of eMaintenance have been described in the literature; however, the capabilities necessary to implement eMaintenance lack proper research. The purpose of this study is to develop a framework that presents the required capabilities and their connection when an organization wants to implement eMaintenance, as well as to identify the outcomes of the transition to eMaintenance. The study is based on an exploratory case study that includes 26 interviews with a digital railway maintenance development company and its main customer, the traffic agency. The study findings are presented in a framework, including five main capabilities for implementing eMaintenance and its relationship within the noted industries. The required capabilities are, namely, digital technology development, organizational development, change of work routines, compliance with regulations, and assuring information security. The framework also analyzes the outcomes of implementing digital maintenance, which demonstrate a variety of economic, environmental, and social benefits.

Development of a backup drive in locomobile construction

Current maintenance and repair of the railway track is a prerequisite for the efficient operation of rail transport. The main task of the current maintenance of the way is to create conditions for ensuring the uninterrupted movement of trains with set speeds and long service life of all elements of the way. In recent years, locomobiles are coming into use. These are hybrid road-rail cars that are able to move both on the railway track and on highways. Locomobiles are made based on the car by installing the mechanisms of extension of the railway chassis on the frame of the car. Trains are constantly moving along the railway tracks, so repairs and maintenance of the track should not disrupt their schedule if it is possible. In case of an unworkable condition of the vehicle located on the railway track, there will be an emergency which requires towing transport and, accordingly, time costs, which accompanies large economic losses. In connection with the above, the task of creating a backup drive in the locomobile is urgent. The article presents the design of a backup drive for the locomobile and describes the principle of its operation. The dependencies for calculating the limiting operating time of the drive and the distance traveled by the vehicle are given, depending on the speed of its movement and the capacity of the battery. The graphs for determining the optimal speed of the locomobile are obtained.

Contract design and performance of railway maintenance: Effects of incentive intensity and performance incentive schemes

In this paper we study the effect of contract design on the performance of railway maintenance in Sweden, using a panel data set over the period 2003–2013. The effect of incentive intensity is estimated, showing that the power of incentive schemes improve performance as measured by the number of infrastructure failures. In addition, we show that the structure of the performance incentive schemes has resulted in a reallocation of effort from failures not causing train delays to failures causing train delays, with a substantial increase in the former type of failures. This signals a deteriorating asset condition, which highlights the need to consider the long-term effects of this incentive structure. Overall, this work shows that the design of the incentive structures has a large impact on the performance of maintenance, and that the estimated effects are important to consider when assessing contract designs within this field.

Improvement of wear resistance in a pearlitic rail steel via quenching and partitioning processing

Improvement of wear resistance and mechanical performance of rails used in heavy-haul railway are essential to reduce railroad maintenance costs. A novel heat treatment based on quenching and partitioning (Q&P) processing was proposed to improve the wear resistance of a hypereutectoid pearlitic rail. 50% of austenite was transformed into martensite under an interrupted quenching from full austenitization temperature to 140 °C. A multiphase microstructure resulted from the quenching and partitioning process, consisting of tempered martensite, bainite, retained austenite, and pearlite colonies. The partitioning step was performed in the range of 350–650 °C. Microstructure characteristics were investigated using scanning electron microscopy, microhardness measurements, X-ray and electron backscattered diffraction. Uniaxial tensile and pin-on-disc tests were also performed to evaluate the mechanical properties and wear resistance. The best combination of wear resistance and mechanical performance was obtained in samples partitioned at 450 and 550 °C, which may be applied in the railway industries.

A Multifeature Hierarchical Locating Algorithm for Hexagon Nut of Railway Fasteners

Fasteners are an important part of railway security. The application of computer vision and image processing on fastener detection has become a research hot spot. However, most of the researches have focused on the missing and damage detection of fasteners up to now. In this paper, a method based on image processing is proposed to locate the center of the hexagon nut in the railway fastener. The precise position of the hexagon nut can be used for the automatic replacement of the nut, which is of great significance for the automatic railway construction and maintenance. The locating method proposed in this paper can be divided into two steps. First, the improved Canny detector which combines surrounding suppression and iterative excitation is used to extract the contours of the fastener. Then, a multifeature hierarchical locating (MHL) algorithm is proposed, which integrates the circle contour of the gasket and the hexagon features of the nut. The experimental results show that the improved Canny detector suppresses noises effectively and highlights the contours of fastener. The MHL algorithm in the next step improves the locating accuracy remarkably while guaranteeing the robustness meantime.

Selection of exploitation data from railway traffic control devices for the purposes of gathering and analyzing data processes from railway transport objects

The evaluation of the technical systems reliability and safety requires collecting and processing of reliable data which characterizes the processes. The data from current exploitation is particularly important for decision-making processes. It can be used for creation of occurring exploitation phenomena models and allows to determine the expected object behaviour in the future. The railway traffic control devices often work in very difficult exploitation and environmental conditions. The information about their technical condition can be gathered and used for a proper prophylaxis as well as a predictive maintenance of railway traffic. It will allow to choose a maintenance strategy which will consist in optimal use of railway traffic control devices.

Railway line capacity utilisation and its impact on maintenance costs

In this paper, we analyse how railway maintenance costs are affected by different levels of railway line capacity utilisation. Previous studies have focused on the wear and tear of the infrastructure, while this paper shows that it is important to also acknowledge the heterogeneity of the maintenance production environment. Specifically, we estimate marginal maintenance costs for traffic using econometric methods on a panel dataset from Sweden and show that these costs increase with line capacity utilisation. The results are significant considering that current EU regulation (2015/909) states that track access charges can be based on marginal costs, with the aim of achieving an efficient use of available infrastructure capacity.

Development of Experiential Safety Education Program to Promote Compliance with “Double Check Rule of Train Schedule Diagram” in Railway Maintenance Work

Development of Experiential Safety Education Program to Promote Compliance with “Double Check Rule of Train Schedule Diagram” in Railway Maintenance Work

Autonomous rolling-stock coupler inspection using industrial robots

In railway rolling-stock maintenance, where the environment is highly unstructured and unpredictable, the detection and localization of smaller components is difficult and remains a key challenge in introducing autonomous systems. This paper presents the design and evaluation of a system, which allows industrial robots to inspect the electric head of railway couplers. The system developed comprising multiple sensors and active-compliant end of arm tooling, is robust to noise and ambiguities. Successful validation of the system is achieved using both an actual coupler in its working environment and an experimental setup that includes a commercial grade industrial robot and a mock coupler.

INTERCONNECTION OF TRANSPORT AND TOURISM INDUSTRY

The interconnection of tourism and transport activity is present at all levels of development of society and economy. The occurrence of rail, then car and plane has led to the transformation of tourism from an individual into a mass phenomenon. The general economic expansion, the rise in living standards, and especially the rapid development of tourism in the 20th century, have had a significant impact on the overall transport system, and especially on change of means of transport. The sudden development of motor vehicles is the beginning of the The Second Transportation Revolution, and at the same time other revolutions in tourism. Tourism is the sector that records the highest growth in the world economy. The aim of this paper is to examine the analysis of interconnections and relations between transport and tourism industry. Tourism and transport are interconnected phenomena, where all major epochs in the development of transport becoming the turning points in the development of tourism. Transportation is an integral part of the tourism industry since it connects tourists with various tourist attractions. In most countries, the development of tourism depends on the development of the transportation system. The promotion and development of tourism depends directly on the development of the transport system (road, maritime, air, rail, river and PTT traffic), maintenance and construction of existing roads, construction and maintenance of railways and air traffic, as well as the construction of local airports and the improvement of flight operations. Serbia has relatively favorable natural and material conditions for the development of various types of traffic in accordance with the requirements of domestic and foreign tourists. Road traffic has a dual importance for tourism. First of all, it allows tourists to travel on vacation with certain advantages that consist of being able to go directly from home, at will, to choose the time of departure, the route and speed they will travel, and the choice of travel companions depends on them. One of the main reasons that led to massive use of cars for tourist purposes is their economic efficiency. The connection between tourism and transport is also evident in the fact that many roads that serve primarily for tourism are built. Air traffic has opened new destinations and tourist forms, such as long distance trips.

Development of integrated railway ballast quality index

ABSTRACT The quality of ballast materials is an important criterion in railway track maintenance management systems. Although various studies have been made on the characteristics of ballast aggregates and ballast mechanical behaviours, making an optimal decision on the selection of appropriate ballast materials is still a serious challenge in the railway industry. It indicates a need for an integrated ballast quality index which could help to ensure improved cost-effectiveness of track maintenance. In response to this need, the mechanical, physical and environmental properties of the ballast were categorised and weighted based on their level of influences on the ballast overall conditions. Consequently, a ballast quality/condition index was developed as a function of the influencing parameters. To examine the practicability and applicability of the developed method/index, three types of ballast materials were taken from different sources and their quality was evaluated and discussed using the new index. Through illustrating the effectiveness of the new index in evaluation of ballast materials, it was shown that the new index can play a role to allocate an optimal ballast material quality and improve cost-effectiveness of the current maintenance by providing the ability to optimise ballast maintenance planning.

Evaluation on the mechanical properties of cement asphalt mortar with quick hardening admixture for railway maintenance

Abstract A new cement asphalt mortar (CAM) stabilized ballast method is expected to reinforce the ballast layer by improving the ballast structural durability with short construction time. In this work, the effect of quick-hardening admixture (QA), and sand on the mechanical performance of CAM are mainly discussed. The test results verified that sand particles behave as an interlayer between the cement particles and asphalt droplets which enhances the mixing stability remarkably. Adding QA not only eliminated the bleeding problem, controlled the workability of the mixture but also contributed to the fast strength development of the mixture.

Development of railway ballast geometry index using automated measurement system

Ballast layer Geometry condition is an important criterion in the railway track maintenance since the track stability strictly depends on the ballast geometry. Currently, a visual inspection is a method of monitoring ballast layer geometry which is considerably costly and time-consuming. Addressing the limitations of the current ballast maintenance approach, a new ballast layer geometry index was established, using an automated measurement system. This index is a function of deficits and excess of ballast in the track. A new maintenance approach was developed based on the new index, providing the possibility of quickly measuring ballast profile for faster and more accurate ballast maintenance. To examine the practicability and applicability of the new method/index, the results of a comprehensive field measurement were used. By illustrating the effectiveness of the new index in the field, it was shown that the new approach can significantly improve the current maintenance methods. It provides the possibility of fast and easy recording ballast layer geometry and maintaining optimum ballast conditions.

Titelbild: Bautechnik 2/2019

AbstractZum Titelbild The transformation of an area originally used for railway maintenance into a new neighbourhood in the city centre is one of the most important urban development projects being carried out in Bristol. The new St Philips footbridge spans the River Avon contributing to provide the needed accessibility for development to a site previously isolated by several infrastructures and the watercourse. The footbridge is an innovative solution to a complex crossing problem: the connection of two banks with a significant elevation and appearance difference and one of them being developed to high architectural standards faster than the other. (Foto: Knights Architects)

Rail defect inspection based on coupled structural–acoustic analysis

The inspection of rail defects is of importance in high-speed railway operation and maintenance. As a highly efficient method for both nondestructive testing and structural health monitoring of the rail, ultrasonic guided waves (UGWs) inspection provide increased sensitivity to smaller defects. These advantages can be fully exploited only if the complexities of UGWs propagation between the medium of air and rail are unveiled and managed for the given inspection method. The development and validation of modeling procedure for the rail based on coupled structural–acoustic model is presented in this paper. Acoustic–structure interaction between air and rail is simulated based on COMSOL Multiphysics software. The transient response and natural characteristics of UGWs in the rail was computed and predicted. Moreover, the displacement distribution of UGWs in the defective rail and nondefective rail are analyzed both in time and frequency domain. A feasible method for detecting small defects in the rail is proposed in the paper. The results indicated that a defect of 8 mm in rail head can be inspected effectively using UGWs with frequencies of 40 kHz and above. And for small defects in rail web, the X-crystallographic direction ultrasonic transducer should be chosen for inspection.

Railroad infrastructure 4.0: Development and application of an automatic ballast support condition assessment system

Abstract Industry 4.0, or the fourth industrial revolution, is the current trend of automation and data exchange in manufacturing technologies. Even though Industry 4.0 emerged as a manufacturing initiative, the idea of bridging digital and physical systems can be expanded beyond the manufacturing industry. “Railroad Infrastructure 4.0” is thus proposed in this study to revolutionize the maintenance operations of the railroad industry. In North America, most primary freight and passenger rail corridors are constructed using ballasted track. One of the primary maintenance activities is to ensure the ballast is performing adequately. Being able to monitor the ballast condition and conduct tamping operations (e.g. maintenance activities) at optimal intervals can increase the safety and efficiency of railroad operations. Previously, techniques such as ground penetrating radar (GPR) and Matrix Based Tactile Surface Sensors (MBTSS) have been used to assess the condition of ballast, but these investigative tools lack the capability of automatically and continuously monitoring the track system. Researchers at the University of Illinois at Urbana-Champaign and the University of South Carolina have developed a non-intrusive method as a key component of Railroad Infrastructure 4.0 to continuously quantify ballast pressure distribution (i.e. ballast condition) under the sleeper (also known as a “crosstie”). This method innovatively uses the bending moment profile across the concrete sleeper, and the approximated rail seat loads as inputs, to back-calculate the ballast support condition through the use of an optimization algorithm. The ballast support condition assessment system that was developed has been validated for accuracy from extensive laboratory experimentation. The laboratory validated system was deployed in the field on a Class I heavy axle load (HAL) freight railroad in the United States to continuously monitor the ballast pressure distribution beneath concrete sleepers in real-time under revenue service operating conditions. The evaluation of ballast pressure distributions between adjacent sleepers as well as tonnage accumulated are also included. To better quantify the variation of ballast pressure beneath the sleepers, the Ballast Pressure Index (BPI) is also proposed. The information presented in this paper demonstrates the concept and potential of Railroad Infrastructure 4.0 as a future framework for railroad maintenance planning and management.