Railway Infrastructure Managers Research Articles

A study on the dynamic train-track interaction over cut-fill transitions on buried culverts

Sudden changes in the structural and geotechnical properties of railway tracks along its course are normally associated with subgrade stiffness transitions, differential settlements and, ultimately, hanging sleepers that reduce the performance of the railway system. This paper aims at analysing and quantifying the impact of such situations, particularly cut-fill transitions combined with the presence of culverts, on the train-track system response. A cut-fill transition on a buried culvert is used as case study for which track geometry and stiffness evaluation data were available. A numerical model, considering the coupled train-track interaction, was developed using a 3D FEM dynamic analysis tool that was further improved here with a mixed implicit-explicit time integration scheme. The results suggest that the faster degradation rates typically found at similar locations are mostly related to the development of early permanent deformations in the subgrade layers, rather than to sudden stiffness transitions, which then aggravate the problem by causing important dynamic amplifications in the train-track interaction. Therefore, numerical approaches similar to the one presented herein can be valuable tools for designers and railway infrastructure managers in order to anticipate and mitigate such negative effects at these locations.

Robust routing and timetabling in complex railway stations

In nearly saturated station areas the limited capacity is one of the main reasons of delay propagation. Spreading the trains well in time and space in these areas has a big impact on the passenger robustness, i.e. the total travel time in practice of all passengers in the railway network in case of frequently occurring small delays. We focus on improving the performance in the bottleneck of the network in order to improve the performance of the whole railway network. This paper proposes a method that builds from scratch a routing plan and a cyclic timetable that optimizes the infrastructure occupation and the passenger robustness. An integer linear routing model assigns, without considering a timetable, every train to a route such that the maximal node usage is minimized and that the number of times that each node is used, is quadratically penalized. Thereafter, a mixed integer linear timetabling model assigns to each train the blocking times at which the nodes on its route, assigned by the routing model, are reserved and released. Different from other approaches is that we focus on the occupation of the railway infrastructure before constructing the timetable. The approach is validated on the complex railway station area of Brussels (Belgium). Our routing plan and timetable from scratch improve the passenger robustness up to 11% compared to a reference timetable and routing plan composed by the Belgian railway infrastructure manager Infrabel and by up to 2% compared to a reference timetable and routing plan from literature.

Detecting train reroutings with process mining

One of the objectives of railway infrastructure managers is to improve the punctuality of their operations while satisfying safety requirements and coping with limited capacity. To fulfil this objective, capacity planning and monitoring have become an absolute necessity. Railway infrastructure managers possess tremendous amounts of data about the railway operations, which are recorded in so-called train describer systems. In this paper, a set of methods is proposed to guide the analysis of capacity usage based on these data. In particular, train connections are categorized according to the severity of train reroutings as well as the diversity of these reroutings. The applied method is able to highlight areas in the railway network, where trains have a higher tendency to diverge from their allocated route. The method is independent from the underlying infrastructure, and can, therefore, be reused effortlessly on new cases. The analysis provides a starting point to improve the planning of capacity usage and can be used to facilitate the communication between capacity planning at one hand and operations on the other hand. At the same time, it presents an illustration on how process mining can be used for analysis of train describer data.

Selection of maintenance, renewal and improvement projects in rail lines using the analytic network process

This paper addresses one of the most common problems that a railway infrastructure manager has to face: to prioritise a portfolio of maintenance, renewal and improvement (MR&I) projects in a railway network. This decision-making problem is complex due to the large number of MR&I projects in the portfolio and the different criteria to take into consideration, most of which are influenced and interrelated to each other. To address this problem, the use of the analytic network process (ANP) is proposed. The method is applied to a case study in which the Local Manager of the public company, who is responsible for the MR&I of Spanish Rail Lines, has to select the MR&I projects which have to be executed first. Based on the results, it becomes evident that, for this case study, the main factor of preference for a project is the location of application rather than the type of project. The main contributions of this work are: the deep analysis done to identify and weigh the decision criteria, how to assess the alternatives and provide a rigorous and systematic decision-making process, based on an exhaustive revision of the literature and expertise.

A Control Scheme for Automatic Level Crossings Under the ERTMS/ETCS Level 2/3 Operation

Level crossing (LC) safety is a crucial issue for railway operators and infrastructure managers. Accidents at LCs give rise to serious material and human damage, while seriously impacting the reputation of railway safety. In particular, some typical scenarios are behind the main part of train-car collisions, which occur at LCs. On the other hand, European Rail Traffic Management System (ERTMS) is the standard railway control-command and signaling system that is currently being implemented throughout Europe and elsewhere. The aim is to ensure railway interoperability while enhancing safety and competitiveness of the railway transportation. ERTMS specifications only provide a rough description when dealing with LC control. This paper elaborates on a functional control architecture for automatic LCs in the context of ERTMS operation Levels 2 and 3. Indeed, these operation levels ensure a continuous knowledge of train location thanks to the Global System for Mobile Communications—Railways link between the trains and the Radio Block Center. Hence, the established LC control scheme aims to ensure an optimal LC command based on the information regarding the train location and, thereby, prevent some potential risky scenarios and improve the global safety at LCs. To achieve this, a generic methodology is employed. First, a formal behavioral model is developed using the time Petri net (TPN) notation. Then, the problem is formalized on the basis of the established TPN, in such a way as to carry out a sound and trustworthy analysis. The various steps of the developed approach are detailed and illustrated in the course of this paper. To the best of our knowledge, this is the first work that seeks to elaborate a control strategy of automatic LC in the ERTMS operation context.

The Impact of Delays of Freight Trains in JIT System on Example One Track Line

The paper describes the problem between freight trains operated by Metrans Danube, a.s. and passenger trains operated by Regiojet, a.s on the line Bratislava – Dunajska Streda - Komarno. It is very important to emphasize this problem because, nowadays, mostly freight trains across the Europe drive in just in time system, it means, that shipments are delivered at exact time and place on time. At this line there are many problems not only this track line is single track, so it is necessary to cross the trains very often in traffic points which maximum 2 traffic tracks but also organizing of transport is more complicated which is provided by Railway infrastructure manager – this case is very important example when railway traffic technology slows down all processes in the logistic chain.

The railway superstructure monitoring in bratislava tunnel no. 1 – section of ballastless track and its transition areas

The requirements for the quality of the railway track with emphasis on its long service life, low maintenance costs and the required parameters of the track geometry have led railway infrastructure manager on the territory of the Slovak Republic – Zeleznice Slovenskej republiky (ZSR) – to modernize or to realize reconstructions of railway lines on the appropriate track sections with the application of the unconventional construction of the railway superstructure (ballastless track). The Department of Railway Engineering and Track Management currently performs the monitoring of two sections with the application of ballastless track construction. This paper is aimed to the monitoring of the ballastless track section and presents the results obtained so far in one of the monitored sections in the Bratislava tunnel No. 1.

Analysis of Results of Monitoring and Prediction of Quality Development of Ballasted and Ballastless Track Superstructure and its Transition Areas

Securing durability of parameter quality of track alignment design and track geometry is a goal of each railway infrastructure manager. To accomplish this goal, various methods and procedures are applied, but they are all based on regular diagnostics, analysis of its results according to valid legislation and design and implementation of respective maintenance and repair works. The technological and economic optimization of planning and implementation of maintenance and repair works, based on prediction of quality development of railway track, is conditioned by precisely implemented and evaluated monitoring. In relation to these facts, the first part of the paper brings an overview of the problem of monitoring the ballastless structure and its transition areas around portals of the Turecky vrch tunnel by methods of complex diagnostics and quality evaluation of the structure including prediction of the structural quality development. The second part of the paper deals with the analysis of the detected errors of the ballastless track with specific focus on transition areas and on the ballasted track. It also summarizes the possibilities of elimination of these errors in building further sections with ballastless track. Modernization of these sections within modernization of ZSR infrastructure is a topical problem.

A concept of technology for freight wagons modernization

Rail transport is a very important part of the modern economy, one of the components determining its dynamic development. It is therefore important to conduct research and taking action aimed at the development and refinement of this branch of industry. Such actions directly translate into an increase in its effectiveness, safety, reduction of burden on the environment and society. Nowadays numerous studies are conducted, aimed at introducing new technologies and solutions, both in terms of railway infrastructure and logistics management systems, as well as in traction vehicles themselves. Introduction of modern technology helps eliminate or reduce nuisance problems associated with the implementation of any kind of transport or the operation of the used technical means. Presented paper concerns an issue of freight wagon modernization using composite materials. It presents a part of a research project that aim is to develop a technology of freight wagons modernization during their periodic repair. The main problem during exploitation of concerned types of freight wagons designed for coal transport is corrosion of the wagon's body shell. The goal of the project is to elongate the period between periodic repairs (by better corrosion protection) and improve conditions of exploitation of modernized freight wagons (for example easier unloading during winter conditions - no freezes of the charge to the freight wagon body shell). One of elements of the project is also to develop a system for diagnosing the technical condition of the modernized shell of wagon body during operation. For this purpose the use of non-destructive testing methods of technical state of constructions will be used, including methods that use the analysis of dynamic response of the object. Application of the composite panels to the freight wagon's body shell was proposed as the solution that can solve mentioned problems during exploitation of freight wagons. The composite panels composed of fiberglass and epoxy resin were proposed. They will be mounted on the body shell using blind rivet nuts. What is more the body shell of the modernized freight wagon will be painted using an anticorrosion agent. The research project is realized by a consortium composed by research units and industry and supported by the Polish National Centre for Research and Development.

Railway infrastructure assurance for Heathrow Express

The purpose of this paper is to show that the assurance process by railway infrastructure managers is not overly onerous and can benefit the project by identifying risks at an early stage in the project’s life cycle and provide guidance on acceptable control measures. The control measures adopted can provide a greater level of certainty on project risk, cost and programme. This paper looks at project risk, operational risk and strategic risk exported by the 2012 London temporary departure terminal as a case study to illustrate the assurance process. It describes how the project is presented to the review panel, how the project is assessed and the control measures adopted for low-, medium- and high-risk projects. The paper details requirements for a tunnel monitoring plan where applicable and the ongoing emergency preparedness planning during the life cycle of the project. It covers the completion of the project with regard to the interface with the Heathrow Express infrastructure.

Managing the Italian High-Speed Railway Network: Provisions for Reducing Interference Between Electric Traction Systems

The Italian high-speed (HS) railway network consists of about 1,000 km of double track lines. It is still growing, and a new section of about 50 km will be put in service in 2016. The HS railway network is broadly equipped, especially in the countryside, with a 2 ? 25 kV, 50 Hz electrification system, while in the urban areas as well as for the HS Rome-Florence line, a 3 kV direct current (dc) electrification system was adopted. The peculiarity of the Italian HS system is the high number of interconnections with the former railway network, called the conventional railway. Twenty double-track interconnections are currently in operation to manage many traffic routes. Since December 2005, when the first 2 ? 25 kV alternating current (ac) line was placed into service, the Italian railway infrastructure management has gained experience in managing the electrical interferences between the 3 kV dc and the 2 ? 25 kV ac electrification systems. This article refers to the main technical aspect related to more than ten years of experience in handling the boundary between different electric traction systems. Figure 1 gives an overview of the Italian HS network. For each line, the first year of service, the relevant electrification system, and the number of interconnections with the conventional railway network are given.

Track geometry degradation and maintenance modelling: A review

Increased demand for railway transportation is creating a need for higher train speeds and axle loads. These, in turn, increase the likelihood of track degradation and failures. Modelling the degradation behaviour of track geometry and development of applicable and effective maintenance strategies has become a challenging concern for railway infrastructure managers. During the last three decades, a number of track geometry degradation and maintenance modelling approaches have been developed to predict and improve the railway track geometry condition. In this paper, existing track geometry measures are identified and discussed. Available models for track geometry degradation are reviewed and classified. Tamping recovery models are also reviewed and discussed to identify the issues and challenges of different available methodologies and models. Existing track geometry maintenance models are reviewed and critical observations on each contribution are provided. The most important track maintenance scheduling models are identified and discussed. Finally, the paper provides directions for further research.

Automated platforming & routing of trains in all Belgian railway stations

Automatically generating train to platform assignments has been an active research area for some time, but systems implementing this research are still not readily available to practitioners. However, now, our train platforming model has been implemented as the tool Leopard inside Infrabel, the Belgian railway infrastructure manager. In practice, initial macroscopic timetables are often not yet feasible inside stations on the microscopic level. This means that a platforming tool must be able to handle cases where not all trains can be platformed or routed. Our model provides a platforming and routing plan for as many trains as possible and puts the remaining trains on a fictive platform. Contrary to the manually made platforming plans, the optimised platforming plans have no platform conflicts nor routing conflicts. Our model assigns as much trains as possible, given the timetable and the available infrastructure. Our tool can solve the platforming problems for all 530 stations in Belgium together in about 10 min. This means (i) it saves many man months of planning time compared to the still common manual practice to platforming and (ii) it achieves higher quality results leading to significantly less in-station train delays in practice.

Estimating the Accuracy of Track-Surveying Trolley Measurements for Railway Maintenance Planning

AbstractMaintenance of the rail track plays an important role in the policies that promote railway transport in the European Union. Each member state has its own railway infrastructure manager that is regulated by the standards set by the European Committee for Standardization (CEN). The standards define three levels for the track geometric quality: the alert limit (AL), the intervention limit (IL), and the immediate action limit (IAL). In the United States, the Federal Railroad Administration (FRA) manages the railroad safety and national rail transportation policy. They classify nine classes of tracks depending on the maximum allowable speed for freight and passenger trains; each classification has its own track geometric limits from nominal values. Usually, track-survey cars are used to measure the parameters of the geometric quality of the tracks in long sectors, whereas traditional surveying methods (TSMs) or an automated measuring system based on a track-surveying trolley assisted by a robotic total...

A contribution for integrated analysis of railway track performance at transition zones and other discontinuities

The authors present a novel approach to anticipating poor track performance, in terms of derailment risk, track degradation and passenger comfort, at critical locations of railway lines, such as transition zones and other discontinuities, including local irregularities. Track geometry data is integrated with information from a numerical study on the effect of track defects on the train-track system and with characteristics of the track superstructure and substructure. The application of the method to a new railway line suggested that track transition zones and other discontinuities, such as changes in the substructure, may trigger rapid track degradation. The proposed approach can provide crucial information for railway infrastructure managers.

Intelligent Transport System – RRUKA Special Issue ‐ Editorial

The Rail Research UK Association (RRUKA) was formed in 2010 with the aim of providing a forum in which industry and academia can come together to identify and deliver fundamental research which will benefit the whole railway system. There are currently 51 institutional members and over 300 RRUKA researchers who have the expertise and skills to develop new concepts to address long standing issues and explore emerging opportunities that the industry is keen to exploit. The association fulfils its objectives through a number of activities, including networking events, conferences, thematic workshops, and facilitating the delivery of academic research. This IET Intelligent Transport System Special Issue presents a selection of research papers presented at the third RRUKA annual conference held in London in 2014. The conference showcased the activities of the members, who presented their latest work both in the plenary speaking sessions, and also in the Blue Sky Village where industry and academic colleagues exchanged ideas and concepts for the next generation of cutting edge solutions. Mark Carne, Chief Executive of Network Rail, set out in his keynote to address the challenges facing the railway, and outlined the future vision of an entirely digitally- enabled railway system. In this future vision the railway system will fully embrace and adopt emerging digital technology in all aspects of its operation, delivering benefits for the passenger, operators, maintainers, and renewals and upgrades. The papers published in this issue cover a broad spectrum of research within the scope of ITS. System wide issues are addressed by the papers on: the whole-system life cost analysis method for railway infrastructure management; the geospatial safety risk model; and electromagnetic compatibility between rolling stock and the surrounding systems. Optimisation of the railway system and its operation is tackled in papers which address: the turnaround arrangements at terminal stations; delay management with minimal energy consumption; and the use of remote condition monitoring for improved wheelset management. The paper examining how passengers have dealt with the increased amount of counter-terrorism measures which are now implemented within stations, and also the paper which addressed how the system is coping with an aging passenger population, particular relating to slips trips and falls, provide relevant research into human factors. Some of the most interesting and creditable work that is undertaken by RRUKA members and supported by industry partners is published in this issue. We hope that you find the papers of value. More information on the association and how you can engage can be found on our website www.rruka.org.uk.

Introduction to the risk management in the maintenance of railway tracks

Risk management is an essential tool for the implementation of safety policy within the framework of safety management systems deployed in all enterprises involved in the management of railway infrastructure and transport operations on the fundamental European Union rail network. The idea of risk management, however, is much younger than the railway system and therefore it is sometimes regarded as an independent supplement to the business of entities related to the railway.The aim of this article is to present how the processes of the railway track maintenance system can be supported by the language of methods of risk management, in order to be able to better integrate these processes with the safety management system of an infrastructure manager. This work also discusses the requirements for safety management systems and indicates further possible directions of research in the field of risk management methods which support processes of maintenance of railway tracks. Keywords: railway track, railway track maintenance system, method of risk management, safety management system

Risk Management at Railroad Grade Crossings: Proposal for a Decision Support System

Managing accident risk at Railway Level Crossings (RLCs) has been an important issue for both railway and highway infrastructure managers and operators. The term risk management of RLCs includes the process which is followed, the means used and measures taken in order to achieve a specific goal related to the aspect of safety of RLCs. Improvement of the safety level can be reached either by reducing the probability of having an accident or by reducing the consequences of the accidents or by their combination. Safety improvement is costly, however what is not often known is its correlation with the required cost. This paper presents a scientific “tool” for managing the safety of RLCs. A methodology is developed in order to assist the railway infrastructure managers to decide on the type and size of the interventions to be made at a level crossing of the railway network in order to improve its safety. The methodology uses the conventional evaluation indicators of the economic efficiency of an investment/project (NPV; IRR; cost/benefit ratio) as a criterion for the decision making; at the same time it enables the correlation of these indicators to the improvement of the safety level. The methodology is then applied to RLCs with specific constructional and operational characteristics. The proposed methodology may be applied in all incident categories and for various causes subject to appropriate modifications.

RESTRAIL Toolbox – An Innovative Solution for Safe, Secure and Resilient Railway Operation

This practical contribution presents the main outcome of a successful research project coordinated by the International Union of Railways (UIC). RESTRAIL (REduction of Suicides and Trespasses on RAILway property; 2011-2014) was a three-year EU FP7 collaborative project which aimed to reduce railway suicides and trespassing fatalities as well as the costly service disruption caused by these events. The project provided the rail industry and researchers worldwide with an analysis and identification of the most cost-effective prevention and mitigation measures and the results are organised into a practical toolbox. The RESTRAIL toolbox is a free online tool with both practical and scientific aims. On the one hand it is a guide of best practice designed to lead railway undertakings and infrastructure managers through the process of selecting from the range of preventative and mitigation measures (through a systematic approach for analysing a problematic situation). It equally provides a wide list of cost-effective measures, implementation tips, examples, empirical evidence for effectiveness and other useful details which are important during the implementation phase. On the other hand, it is based on empirical evidence collected from the scientific literature and from the railway industry, as well as on data produced during 11 pilot tests which were implemented during the project. The RESTRAIL toolbox is a good example of exploitable results from EU-funded projects: the tool was developed during the project, it is currently easy to consult and available free of charge at www.restrail.eu/toolbox, and will continue to be maintained, updated and improved by the International Union of Railways (UIC) for the benefit of the entire railway community and society.

Novel Efficient Technologies in Europe for Axle Bearing Condition Monitoring – the MAXBE Project

Axle bearing damage with possible catastrophic failures can cause severe disruptions or even dangerous derailments, potentially causing loss of human life and leading to significant costs for railway infrastructure managers and rolling stock operators. Consequently the axle bearing damage process has safety and economic implications on the exploitation of railways systems. Therefore it has been the object of intense attention by railway authorities as proved by the selection of this topic by the European Commission in calls for research proposals. The MAXBE Project (http://www.maxbeproject.eu/), a EU-funded project, appears in this context and its main goal is to develop and to demonstrate innovative and efficient technologies which can be used for the onboard and wayside condition monitoring of axle bearings. The MAXBE (interoperable monitoring, diagnosis and maintenance strategies for axle bearings) project focuses on detecting axle bearing failure modes at an early stage by combining new and existing monitoring techniques and on characterizing the axle bearing degradation process. The consortium for the MAXBE project comprises 18 partners from 8 member states, representing operators, railway administrations, axle bearing manufactures, key players in the railway community and experts in the field of monitoring, maintenance and rolling stock. The University of Porto is coordinating this research project that kicked-off in November 2012 and it is completed on October 2015.Both on-board and wayside systems are explored in the project since there is a need for defining the requirement for the onboard equipment and the range of working temperatures of the axle bearing for the wayside systems. The developed monitoring systems consider strain gauges, high frequency accelerometers, temperature sensors and acoustic emission. To get a robust technology to support the decision making of the responsible stakeholders synchronized measurements from onboard and wayside monitoring systems are integrated into a platform. Also extensive laboratory tests were performed to correlate the in situ measurements to the status of the axle bearing life. With the MAXBE project concept it will be possible: to contribute to detect at an early stage axle bearing failures; to create conditions for the operational and technical integration of axle bearing monitoring and maintenance in different European railway networks; to contribute to the standardization of the requirements for the axle bearing monitoring, diagnosis and maintenance. Demonstration of the developed condition monitoring systems was performed in Portugal in the Northern Railway Line with freight and passenger traffic with a maximum speed of 220 km/h, in Belgium in a tram line and in the UK. Still within the project, a tool for optimal maintenance scheduling and a smart diagnostic tool were developed.This paper presents a synthesis of the most relevant results attained in the project. The successful of the project and the developed solutions have positive impact on the reliability, availability, maintainability and safety of rolling stock and infrastructure with main focus on the axle bearing health.