932 research outputs found

    Assessment of Railway Train Energy Efficiency and Safety Using Real-time Track Condition Information

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    This paper presents the use of track condition data from the virtual remote wireless sensor network within a simulation model of a battery-hybrid diesel-electric locomotive-driven freight train for a realistic mountain railway route simulation scenario. Simulation model includes the point-mass model of freight train longitudinal motion dynamics subject to wheel-to-track adhesion and head wind variations, the model of hybrid diesel-electric locomotive energy efficiency, and the model of real-time information provide to the virtual train driver about railway track conditions based on a narrow-band wireless remote sensor network. Simulation results are used to assess the possible benefits remote wireless sensor data for freight train energy-optimal control and to increase the transportation safety, including prediction of possible delays due to changed weather conditions en route

    Infrastructure Design, Signalling and Security in Railway

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    Railway transportation has become one of the main technological advances of our society. Since the first railway used to carry coal from a mine in Shropshire (England, 1600), a lot of efforts have been made to improve this transportation concept. One of its milestones was the invention and development of the steam locomotive, but commercial rail travels became practical two hundred years later. From these first attempts, railway infrastructures, signalling and security have evolved and become more complex than those performed in its earlier stages. This book will provide readers a comprehensive technical guide, covering these topics and presenting a brief overview of selected railway systems in the world. The objective of the book is to serve as a valuable reference for students, educators, scientists, faculty members, researchers, and engineers

    Comparative study between an alternating current (AC) and a direct current (DC) electrification of an urban railway

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    This study will evaluate technically, energetic and economically the traction electrification network of the line Barcelona – Vallès operated by Ferrocarrils de la Generalitat de Catalunya (FGC) in the existing voltage system (1500 Vdc) and a new electrification under alternative current (25 kVac) will be proposed to be as well studied. The results obtained will be compared in order to obtain decision factors on which system best fits

    Analysis, Evaluation and Simulation of Railway Diesel-Electric and Hybrid Units as Distributed Energy Resources

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    The objective of this paper involves the analysis, identification and evaluation of different possibilities offered by technology for the improvement and the management of the use of energy and hybridization in railways: On board generation, demand response and energy storage, both in traction and auxiliary loads, considering the aggregation of resources and its stochastic nature. The paper takes into account the importance of efficient use of energy in railways, both currently (trains in service, prototypes) and in the future, considering the trends driven by energy policy scenarios (2030–2050) that will affect service and operation of units during their lifetime. A new activity has been considered that will be relevant in the future in the framework of a new electricity supply paradigm: Smart-Grids. According to this paradigm, the interaction of the Electric Power System and the Railway Supply System (somehow embedded in the Power System) will bring new opportunities for the collaboration of these two systems to perform, in a wise economic fashion, a better and more reliable operation of the complete energy system. The paper is focused on a mixed profile with low-medium traffic (passenger and freight): The first part of the route is electrified (3 kV DC catenary) whereas the second part is not electrified. Results justify that complex policies and objectives bring an opportunity to make cost-effective the hybridization of railway units, especially in low/medium traffic lines, which improves their social and economic sustainability.Authors are very grateful to the information, data and technical discussions provided by Patentes Talgo S.A. (Spain). This work was supported by the Ministerio de Ciencia, Innovación y Universidades (Spanish Government) under research project ENE-2016-78509-C3-2-P; Ministerio de Educación (Spanish Government) under grant FPU17/02753 and especially EU FEDER funds. This work was supported by the Ministerio de Ciencia, Innovación y Universidades, Spanish Government) under research project ENE-2016-78509-C3-2-P; Ministerio de Educación through grant FPU17/02753 and EU FEDER funds. Authors have also received funds from these grants for covering the costs to publish in open access

    Train Braking

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    Analysis of Ballast Transport in the Event of Overflowing of the Drainage System on High Speed Lines

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    The transport of ballast caused by the overflowing of longitudinal drains is a prime example of the interactions between the railway track and its environment. In such conditions, water flowing from the platform, along with debris, may drag the ballast off the track foundation. The rate of ballast erosion rises when obstacles are placed along the platform. To better understand the phenomenon of ballast transport, research was undertaken in collaboration with Ecole Polytechnique Fédérale de Lausanne (EPFL). Systematic tests were performed on a physical model, using a 1:3 scale factor, under both normal and severe operational conditions, as well as in the case of a platform obstructed by obstacles. Numerical simulations were also run to evaluate different optimised configurations for the drainage system of the platform. The obtained results have improved the understanding of the phenomenon of ballast transport and have made it possible to identify at risk areas where the overflowing may negatively affect the railway traffic

    Failures in transport infrastructure embankments

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    To ensure that road and rail transport networks remain operational, both highway and railway embankments require continual maintenance and renewal to mitigate against ongoing deterioration and repair any sections damaged by realised failures. This paper provides a review of recent developments in the understanding of highway and railway embankment degradation and failure. Failures due to pore water pressure increase, seasonal shrink-swell deformation and progressive failure are considered. The material composition and construction of highway and railway embankments differ, which influences the dominant type and timing of embankment failure. There is evidence for highway embankment failures induced by pore water pressure increase, but not seasonal deformation and progressive failure. Some railway embankments are susceptible to pore water pressure increase, seasonal shrink-swell deformation and progressive failure due to the age and nature of the dumped clay fill used in their construction. The approaches used to measure and explore embankment failure mechanisms are compared and discussed. Field observations have been used to understand pore water pressure increase and seasonal shrink-swell deformation in embankments, while the investigation of progressive embankment failure has mainly utilised physical and numerical modelling approaches. Further field and laboratory investigation is required before the rigorous analysis of embankment failure can be routinely undertaken. However, progress is being made to empirically identify and evaluate the various risk factors affecting transport infrastructure embankment failure

    Numerical analysis of deformation and stability in the formation for railway tracks

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    Over the past few decades, the increasing demands of railways operations in the form of heavy loading and high speed have been noticed. Railway formation and ballast deform progressive under heavy axle cyclic loading, therefore the rail track needs proper design of ballast and formation bed to achieve the desire stiffness and stability for the safe and sound serviceability of the track. For the overall stability of the track on soft formation, the ground is improved by different techniques prior to the construction on that, in order to avoid the failure and differential settlement during the designed trains operation. The numerical analyses illustrate that the total deformation and bearing capacity of the railway tracks mostly depend on the changes in the friction angle and cohesion of the selected soils of the subgrade. To avoid failure in the formation of track under the design loads, the proper selection of types of soils, its layer thickness, well compaction during construction and provision of proper track drainage system are extremely important. For the construction of new railway tracks the soils having greater values of friction angle, cohesion and elastic stiffness with the well graded ballast cushion under the sleepers of designed side slopes can be used to reduce the maintenance cost, considerably increase the life time of the components of the tracks and ultimately give better performance of the tracks

    A New Multi-objective Solution Approach Using ModeFRONTIER and OpenTrack for Energy-Efficient Train Timetabling Problem

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    Trains move along the railway infrastructure according to specific timetables. The timetables are based on the running time calculation and they are usually calculated without considering explicitly energy consumption. Since green transportation is becoming more and more important from environmental perspectives, energy consumption minimization could be considered also in timetable calculation. In particular, the Energy-Efficient Train Timetabling Problem (EETTP) consists in the energy-efficient timetable calculation considering the trade-off between energy efficiency and running times. In this work, a solution approach to solve a multi-objective EETTP is described in which the two objectives are the minimization of both energy consumption and the total travel time. The approach finds the schedules to guarantee that the train speed profiles minimize the objectives. It is based on modeFRONTIER and OpenTrack that are integrated by using the OpenTrack Application Programming Interface in a modeFRONTIER workflow. In particular, the optimization is made by modeFRONTIER, while the calculation of the train speed profiles, energy consumption and total travel time is made by OpenTrack. The approach is used with Multi-objective Genetic Algorithm-II and the Non-dominating Sorting Genetic-II, which are two genetic algorithms available in modeFRONTIER. The solution approach is tested on a case study that represents a real situation of metro line in Turkey. For both algorithms, a Pareto Front of solution which are a good trade-off between the objectives are reported. The results show significant reduction of both energy consumption and total travel time with respect to the existing timetable

    Leveraging Connected Highway Vehicle Platooning Technology to Improve the Efficiency and Effectiveness of Train Fleeting Under Moving Blocks

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    Future advanced Positive Train Control systems may allow North American railroads to introduce moving blocks with shorter train headways. This research examines how closely following trains respond to different throttle and brake inputs. Using insights from connected automobile and truck platooning technology, six different following train control algorithms were developed, analyzed for stability, and evaluated with simulated fleets of freight trains. While moving blocks require additional train spacing beyond minimum safe braking distance to account for train control actions, certain following train algorithms can help minimize this distance and balance fuel efficiency and train headway by changing control parameters
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