| 1. |
- Arasteh Khouy, Iman, et al.
(author)
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Evaluation of track geometry maintenance for a heavy haul railroad in Sweden: A case study
- 2014
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 228:5, s. 496-503
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Journal article (peer-reviewed)abstract
- The measurement and improvement of track quality are key issues in determining both the restoration time and cost of railway maintenance. Applying the optimal tamping strategy helps reduce maintenance costs, making operations more cost effective and leading to increased safety and passenger comfort. In this paper, track geometry data from the iron ore line (Malmbanan) in northern Sweden, which handles both passenger and freight trains, are used to evaluate track geometry maintenance in cold climate. The paper describes Trafikverket’s (Swedish Transport Administration) tamping strategy and evaluates its effectiveness in measuring, reporting, and improving track quality. Finally, it evaluates the performance of the maintenance contractor and discusses the importance of the functional requirements stated in the outsourcing contracts.
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| 2. |
- Arasteh khouy, Iman, et al.
(author)
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Geometrical degradation of railway turnouts : a case study from a Swedish heavy haul railroad
- 2014
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 228:6, s. 611-619
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Journal article (peer-reviewed)abstract
- Turnouts are critical components of track systems in terms of safety, operation and maintenance. Each year, a considerable part of the maintenance budget is spent on their inspection, maintenance and renewal. Applying a cost-effective maintenance strategy helps to achieve the best performance at the lowest possible cost. In Sweden, the geometry of turnouts is inspected at predefined time intervals using the STRIX / IMV 100 track measurement car. This study uses time series for the measured longitudinal level of turnouts on the Iron Ore Line (Malmbanan) in northern Sweden. Two different approaches are applied to analyse the geometrical degradation of turnouts due to dynamic forces generated by train traffic. In the first approach, the recorded measurements are adjusted at the crossing point and then the relative geometrical degradation of turnouts is evaluated by using two defined parameters, the absolute residual area and the maximum settlement, In the second approach, various geometry parameters are defined to estimate the degradation in each measurement separately. The growth rate of the longitudinal level degradation as a function of million gross tonnes / time is evaluated. The proposed methods are based on characterisation of the individual track measurements. The results facilitate correct decision-making in the maintenance process through understanding the degradation rate and defining the optimal maintenance thresholds for the planning process. In the long run, this can lead to a cost-effective maintenance strategy with optimised inspection and maintenance intervals.
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| 3. |
- Arasteh khouy, Iman, et al.
(author)
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Geometrical degradation of switches and crossings on a Swedish heavy haul railroad : a case study
- 2013
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In: Proceedings of 10th International Heavy Haul Association Conference. - New Delhi, India. - 9788192651903 ; , s. 26-32
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Conference paper (peer-reviewed)abstract
- Switches and crossings (S&Cs) are one of the most critical components of railway track systems in terms of safety, operation and maintenance. Each year, a considerable part of the maintenance budget is spent on inspection, maintenance and renewal of S&Cs. However, applying a cost-effective maintenance strategy helps to achieve the best performance at the lowest possible cost. In Sweden, the geometry of S&Cs is inspected at pre-defined time intervals by the STRIX track measurement car. In this paper, time series for the measured longitudinal level of S&Cs on the Iron Ore Line (Malmbanan) in northern Sweden have been used. Two parameters have been defined in this study, namely the absolute residual area (ARa) and the maximum settlement (Smax), to analyse the geometrical degradation of switches and crossings due to dynamic forces generated from train traffic. The paper also evaluates the growth rate of the longitudinal level degradation as a function of million gross tonnes (MGT). The results facilitate correct decision making in the maintenance process through understanding the degradation rate and defining the optimal maintenance thresholds for the planning process. In the long run this will lead to a cost-effective maintenance strategy with optimized inspection and maintenance intervals.
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| 4. |
- Arasteh khouy, Iman, et al.
(author)
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Optimisation of track geometry inspection interval
- 2014
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 228:5, s. 546-556
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Journal article (peer-reviewed)abstract
- The measurement and improvement of track quality are key issues in determining the time at which railway maintenance must be performed and its cost. Efficient track maintenance ensures optimum allocation of limited maintenance resources which has an enormous effect on maintenance efficiency. Applying an appropriate tamping strategy helps reduce maintenance costs, making operations more cost-effective and leading to increased safety and passenger comfort levels. This paper discusses optimisation of the track geometry inspection interval with a view to minimising the total ballast maintenance costs per unit traffic load. The proposed model considers inspection time, the maintenance-planning horizon time after inspection and takes into account the costs associated with inspection, tamping and risk of accidents due to poor track quality. It draws on track geometry data from the iron ore line (Malmbanan) in northern Sweden, used by both passenger and freight trains, to find the probability distribution of geometry faults.
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| 5. |
- Arasteh khouy, Iman
(author)
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Optimization of track geometry maintenance : a study of track geometry degradation to specify optimal inspection intervals
- 2011
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Licentiate thesis (other academic/artistic)abstract
- Railway infrastructure is a complex system which comprises different subsystems. Long useful life span is one of the important aspects of this prime mode of transport. The useful life length of its assets is highly dependent on the maintenance and renewal strategy used during its life cycle. Today’s demands on the railway industry call for increased capacity, including more trains, travelling at higher speeds with higher axle loads. This increased usage will result in higher degradation of railway asset and higher maintenance costs. However, due to the competitive environment and limited budgets, railway infrastructure managers are compelled to optimize operation and maintenance procedures to decrease operation and maintenance costs while meeting high safety standards. To assure track safety and maintain high quality, a cost effective track maintenance strategy is required, one based not only on technical and/or safety limits but also on cost-effective maintenance thresholds. RAMS (Reliability, Availability, Maintainability and Safety) and LCC (Life Cycle Cost) analyses, which are derived from reliable track condition data, provide an approach to specify cost effective maintenance strategy to lessen corrective maintenance actions and downtimes.One of the main parameters to assure railway safety and comfortable railway service is to maintain high quality of track geometry. Poor track geometry quality, directly or indirectly, may result in safety problems, speed reduction, traffic disruption, greater maintenance cost and higher degradation rate of the other railway components (e.g. rails, wheels, switch, crossings etc.). The aim of this study is to develop a methodology to optimize track geometry maintenance by using historical geometry data. The methodology is based on reliability and cost analysis and supports the maintenance decision-making process to identify cost-effective inspection interval. An important phase of track geometry maintenance optimization is to estimate the track degradation rate. Obtaining knowledge about degradation helps to properly schedule maintenance activities such as inspection and tamping.The thesis provides a methodology to identify a cost-effective inspection interval based on track degradation rate and cost drivers. It contains state-of-the-art track geometry maintenance optimization. It describes Trafikverket’s (Swedish Transport Administration) maintenance strategy regarding measurements, reporting on and improving track quality, and it evaluates the efficiency of this strategy. Finally, it includes a case study carried out on the iron ore line in north of Sweden that runs from Boden to Gällivare to evaluate track geometry degradation and analyze the probability distributions of failures. A cost model is developed in order to find optimal inspection interval.Keywords: Track geometry degradation, Track maintenance optimization, Maintenance planning, Tamping
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| 6. |
- Asplund, Matthias, et al.
(author)
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Condition monitoring of rolling stock wheels : approach towards maintenance decision making
- 2014
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In: 27th International Congress on Condition Monitoring and Diagnostic Engineering (COMADEM 2014). - : COMADEM International.
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Conference paper (peer-reviewed)abstract
- Due to the more or less fixed inherent capacity of a railway system, capacity consuming events like failures within a railway network should be kept to a minimum. This could be achieved by the use of existing and new condition monitoring systems which can detect, report and predict failure events in an early stage. Demands for higher service quality, higher capacity, network availability and track quality together with less human intervention on tracks, drive the development of railway condition monitoring systems.Failure driven capacity consumption due to worn or defected rolling stock wheels have a big impact on the capacity and the infrastructure condition. Wheel defects such as out-of-round wheels, generates high forces, and could result in large capacity consumption especially for areas with cold climate conditions. Bad wheels cause even higher track wear that reduce the life length of the track. Wheels with fatigue defects could also influence the track safety issues. This paper presents how different wheel defects can be monitored; together with a review of the most common wayside condition monitoring systems on the Swedish railway network. The study also describes how the decision making process could take advantage of the condition monitoring data in order to increase the achieved network capacity.
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| 7. |
- Backe, Björn
(author)
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The need of condition monitoring to support simulations when predicting system availability of Functional Products
- 2014
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Licentiate thesis (other academic/artistic)abstract
- Today, competition among product manufacturers has increased and many facebeing copied and thus losing their uniqueness. To differentiate on the market,new businesses, which extend the manufacturer’s responsibility throughsupporting and guaranteeing product performance, thus offering more value-creating activities, have received increasing interest.The concepts of Functional Products or Total Offers have emerged through the realization that it is tougher to compete with hardware products only. The Functional Products concept combines the development of hardware, software, services and management of operation, thereby integrating value-adding activities into complete offers. Offering a Functional Product is usually a lifecycle commitment (long-term business-to-business agreement) between the function provider and customer. In this type of business, agreed-upon availability is of importance, especially since the availability of a function can directly influence customers’ productivity. The provider and customer need to predict and evaluate the availability of the function, both in early phases of the product development process and continuously during operation throughout the contracted time. In this thesis, in paper A, a model for predicting and monitoring industrial system availability has been proposed to enable the provider of Functional Products to continuously evaluate, through simulation, the offer in terms of availability performance. The model integrates hardware, support system and monitoring system components and through this approach it is possible to utilize operational data in simulations for continuous prediction of availability during operation. Further, the results of paper B presented in this thesis may extend and improve the model proposed in paper A, if implemented. The results of paper B describe the addition of data stream forecasting to the data stream management fault detection system and have showed improved prediction capabilities. The approach to evaluate the availability in paper A may also be extended and improved through the results presented and demonstrated in paper C. In paper C, a software tool to predict system availability has been developed and demonstrated with data from a real industrial system. The results from the simulation demonstrated, together with the addition of the partitioned multi-objective risk method in paper C, provided an indication of what level of availability may be guaranteed for the product; thus, the approach may be used to compare the availability performance of different designs.
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| 8. |
- Desai, Ajay, et al.
(author)
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Experimental setup and methodology for the analysis of rail lubricant effectiveness
- 2011
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In: Proceedings of the 24th International Congress on Condition Monitoring and Diagnosis Engineering Management. - : COMADEM International. ; , s. 592-598
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Conference paper (peer-reviewed)abstract
- Rail and wheel wear is a complex problem. Lubrication plays an important role in reducing wear and enhancing asset life. Curves and switches are the areas of major challenges. Tight curves when running dry shows wear rates higher to rapid wear, increased maintenance costs and non-availability of track due to maintenance or replacement. The economic analysis based on cut-off radius, lubricants and applicators takes a very long time using field data. Rail operators often face difficulties when selecting lubricants. Lubricant manufactures use different test standards when specifying lubricant properties. Four-ball test fails to give a meaningful indication of lubricant performance. The result is often a complex decision problem in ranking different lubricants under a particular axel load. An appropriate selection of lubricant for a particular rail application can give financial returns and extension of asset life. An experimental set up has been proposed in this paper. The experimental results are expected to be used for development of models on effective lubrication. This paper proposes experimental setups and methodology for analysis of lubrication effectiveness in heavy haul lines. Theories along with existing research to date relating to ranking of lubricants for rail applications and a criterion for the ranking is discussed. An analysis is carried out to compare lubricants used in Australian Heavy Haul lines based on manufacturer supplied specifications and experimental results.
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| 9. |
- Larsson-Kråik, Per-Olof
(author)
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Managing avalanches using cost-benefit-risk analysis
- 2012
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In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 226:6, s. 641-649
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Journal article (peer-reviewed)abstract
- Malmbanan, the Swedish Iron Ore Line, runs through rough terrain including high mountains, peat, terraces situated on fjords, and numerous short bridges and culverts. The area is sub-arctic and mountainous, with a sharp gradient between the part with a maritime climate and that with a continental climate. Global warming and new climate conditions are increasing the risk of slab and snow avalanches. A cost-benefit-risk analysis, dealing with slab and snow avalanches, high spring temperatures with fast snow melting, high water levels and heavy rainfalls, was performed in 2001. A number of at-risk sections along the track were identified and some of the risks were later addressed with changes in the infrastructure and changes in train operation during bad weather conditions. During the past 10 years, the various actions taken have been continuously improved. An evaluation based on operational data shows a lower risk of trains running into hazard areas and better control of slab and snow avalanches. Other improvements are better control and monitoring of rock falls and a lowered risk for trains operating during bad weather conditions. The technical systems in use consist of instrumented arrays of poles placed along the track to indicate avalanches. Bridges have been built to permit avalanches to pass under the railway and artificial tunnels have been designed and constructed to allow avalanches to pass over the railway. Rock fall nets have been put into service and professional avalanche inspection teams have been used for risk evaluation during high-risk weather conditions
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| 10. |
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| 11. |
- Morant, Amparo, et al.
(author)
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Dependability improvement through configuration management : A study of railway signalling systems
- 2013
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In: International Journal of COMADEM. - 1363-7681. ; 16:4, s. 31-40
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Journal article (peer-reviewed)abstract
- The reliability, maintainability and related maintenance support of signalling systems affect the railway network´s availability. Constituting a system-of-systems spread over a wide geographical area, signalling systems consist of a large number of items with different lifecycles making it a challenge to define and describe the structure and relationship between the system’s inherent items at any specific time. System configuration describes a system’s structure to which other data sources can be related. Some current research discusses asset maintenance management in the railway infrastructure, but not many holistic approach deals with signalling systems. The purpose of this paper is to investigate how the process of configuration management, can improve the dependability of the railway system. The paper presents a model for the configuration management of railway signalling systems. The model is based on the results of company surveys and interviews, data analysis and literature review. This model provides better control and visibility of the information related to the system and any changes made to it. Faster and better failure diagnostics can be performed, thus improving maintenance performance. This, in turn, provides better availability of the system by reducing the downtime of the railway network; hence, an improvement in maintainability is also achieved.
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| 12. |
- Morant, Amparo, et al.
(author)
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Information logistics for maintenance of railway signalling systems : A case study
- 2013
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In: The international Journal of railway technology. - : Civil-Comp, Ltd.. - 2049-5358 .- 2053-602X. ; 2:2, s. 97-112
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Journal article (peer-reviewed)abstract
- The purpose of this paper is to explore the use of information logistics for railway signalling systems to improve the efficiency of their corrective maintenance. The signalling system is used to control, supervise and protect railway traffic; therefore, its reliability, maintainability and related maintenance support affect the availability of the railway network. The paper reviews the current status of the maintenance of railway signalling systems, looking at company surveys and company data for a specific case study and consulting relevant literature. It describes how and where data are processed and analyses corrective maintenance work orders to determine how much time is spent on corrective action and knowledge management Areas of improvement are identified and possible improvements are proposed. The efficiency of information logistics has a clear effect on the dependability of the railway signalling system. Signalling systems’ performance can be improved by having better control of and accessibility to the information required for each maintenance action.
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| 13. |
- Morant, Amparo, et al.
(author)
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Knowledge management in a railway network: The case of signalling systems
- 2014
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In: Proceedings of the Second International Conference on Railway Technology. - Kippen : Civil-Comp Press. - 9781905088591
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Conference paper (peer-reviewed)abstract
- The railway network is a complex system with several technologies and a multitude of stakeholders working together to solve problems created by the increasing demands on capacity, speed and mobility for the transportation of goods and passengers. However, the presence of many different stakeholders complicates knowledge management and transfer. The purpose of this paper is to analyse the potential for improving inter-organisational knowledge management in the maintenance of railway signalling systems and make concrete suggestions for improvements. Even if information logistics processes can disseminate explicit knowledge on the maintenance of railway signalling systems, they cannot handle the tacit knowledge transfer that often is crucial. The study finds considerable potential for improving the knowledge management process. It suggests possible measures and makes suggestions for future studies.
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| 14. |
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| 15. |
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| 16. |
- Palo, Mikael, et al.
(author)
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Maintenance performance Improvement for rolling stock wheels
- 2013
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In: PHM2013: 2013 Prognostic and System Health Management. - : AIDIC Servizi S.r.l.. - 9788895608242 ; , s. 727-732
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Conference paper (peer-reviewed)abstract
- The service life of a railway wagon wheel can be significantly reduced through failure or damage, leading to excessive costs and accelerated deterioration. In order to monitor the performance of wheels on heavy haul wagons, this paper proposes implementing the Plan, Do, Study, and Act (PDSA) maintenance performance improvement process. As a case study, it looks at wheels on the heavy haul wagons of a Swedish company, considering all factors that may influence the need for maintenance. After investigating the PDSA process, it proposes the use of Key Performance Indicators (KPIs) for both risk and economic reasons. The paper concludes that the PDSA process and KPIs are useful tools to improve the maintenance performance of railway wheels
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| 17. |
- Palo, Mikael, et al.
(author)
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Rolling stock condition monitoring using wheel/rail forces
- 2012
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In: Insight. - : British Institute of Non-Destructive Testing (BINDT). - 1354-2575 .- 1754-4904. ; 54:8, s. 451-455
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Journal article (peer-reviewed)abstract
- Railway vehicles are efficient because of the low resistance in the contact zone between wheel and rail. In order to remain efficient, train operators and infrastructure owners need to keep rails, wheels and vehicles in an acceptable condition. Wheel wear affects the dynamic characteristics of vehicles and the dynamic force impact on the rail. The shape of the wheel profile affects the performance of railway vehicles in different ways. Wheel condition has historically been managed by identifying and removing wheels from service when they exceed an impact threshold. Condition monitoring of railway vehicles is mainly performed using wheel impact load detectors and truck performance detectors. These systems use either forces or stress on the rail to interpret the condition. This paper will show measurements taken at the research station outside Luleå in northern Sweden. The station measures the wheel/rail forces, both lateral and vertical, at the point of contact in a curve with a 484 m radius at speeds of up to 100 km/h. Data are analysed to show differences for various wheel positions and to determine the robustness of the system.
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| 18. |
- Patra, Ambika Prasad, et al.
(author)
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Availability target of the railway infrastructure : an analysis
- 2010
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In: 2010 proceedings. - Piscataway, NJ : IEEE Communications Society. - 9781424451029
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Conference paper (peer-reviewed)abstract
- The railway has been accepted as one of the most environmentally friendly modes of transport for goods and passengers. However, the railway sector is striving to increase its capacity to meet the growing demand for the transport of goods and passengers with a high level of punctuality in its services. Higher availability requires the effective operation and maintenance of infrastructure, often necessitating the implementation of cost-effective preventive maintenance strategies. Therefore, a higher availability target means higher maintenance investment. However, the question of setting the availability target for the infrastructure is not easy, as it involves many influencing decision parameters, apart from a good understanding of the network configuration and traffic density. Railway networks that have a smaller number of trains and a low punctuality requirement do not require higher availability targets. The aim of this paper is to estimate the availability target for railway infrastructure based on the capacity and punctuality requirements of infrastructure managers and train operating companies. The objectives of the paper are to develop an approach to i) estimating the capacity of the infrastructure based on the design and operational characteristics and evaluating the influence of infrastructure availability on the required capacity and ii) estimating the volume of primary and secondary delay due to failures and maintenance of the infrastructure and establishing the relationship between availability and punctuality requirements. To achieve these objectives, an example is presented with parameters drawn from failure, maintenance and traffic data. Finally, a model has been developed in Petri-Nets to establish a relationship between availability, capacity and punctuality. Monte Carlo simulation is used to establish the relationship. The simulation results illustrate the effect of infrastructure availability on train delays and capacity.
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