1,199 research outputs found

    Modelling rail track deterioration and maintenance: current practices and future needs

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    As commercialisation and privatisation of railway systems reach the political agendas in a number of countries, including Australia, the separation of infrastructure from operating business dictates that track costs need to be shared on an equitable basis. There is also a world-wide trend towards increased pressures on rail track infrastructure through increases in axle loads and train speeds. Such productivity and customer service driven pressures inevitably lead to reductions in the life of track components and increases in track maintenance costs. This paper provides a state-of-the-art review of track degradation modeling, as well as an overview of track maintenance decision support systems currently in use in North America and Europe. The essential elements of a maintenance optimisation model currently under development are also highlighted

    Modeling the energy consumption of trains by applying neural networks

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    [EN] This paper presents the training of a neural network using consumption data measured in the underground network of Valencia (Spain), with the objective of estimating the energy consumption of the systems. After the calibration and validation of the neural network using part of the gathered consumption data, the results obtained show that the neural network is capable of predicting power consumption with high accuracy. Once fully trained, the network can be used to study the energy consumption of a metro system and for testing the hypothetical operation scenarios.The realization of this paper was possible thanks to the collaboration agreement signed between the Universitat Politecnica de Valencia and Ferrocarrils de la Generalitat Valenciana, and funding obtained by the Spanish Ministry of Economy and Competitiveness, through the project "Strategies for the design and energy-efficient operation of railway and tramway infrastructure'' (Ref. TRA2011-26602).Pineda-Jaramillo, JD.; Insa Franco, R.; Martínez Fernández, P. (2018). Modeling the energy consumption of trains by applying neural networks. Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit. 232(3):816-823. https://doi.org/10.1177/0954409717694522S816823232

    System energy optimisation strategies for DC railway traction power networks

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    Energy and environmental sustainability in transportation are becoming ever more important. In Europe, the transportation sector is responsible for about 32% of the final energy consumption. Electrified railway systems play an important role in contributing to the reduction of energy usage and C02_2 emissions compared with other transport modes. Previous studies have investigated train driving strategies for traction energy saving. However, few of them consider the overall system energy optimisation. This thesis analyses the energy consumption of urban systems with regenerating trains, including the energy supplied by substations, used in power transmission networks, consumed by monitoring trains, and regenerated by braking trains. This thesis proposes an approach to searching energy-efficient driving strategies with coasting controls. A Driver Advisory System is designed and implemented in a field test on Beijing Yizhuang Subway Line. The driver guided by the DAS achieves 16% of traction energy savings, compared with normal driving. This thesis also proposes an approach to global system energy consumption optimisation, based on a Monte Carlo Algorithm. The case study indicates that the substation energy is reduced by around 38.6% with the system optimised operations. The efficiency of using regenerative braking energy is improved to from 80.6 to 95.5%

    Maximum risk reduction with a fixed budget in the railway industry

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    Decision-makers in safety-critical industries such as the railways are frequently faced with the complexity of selecting technological, procedural and operational solutions to minimise staff, passengers and third parties’ safety risks. In reality, the options for maximising risk reduction are limited by time and budget constraints as well as performance objectives. Maximising risk reduction is particularly necessary in the times of economic recession where critical services such as those on the UK rail network are not immune to budget cuts. This dilemma is further complicated by statutory frameworks stipulating ‘suitable and sufficient’ risk assessments and constraints such as ‘as low as reasonably practicable’. These significantly influence risk reduction option selection and influence their effective implementation. This thesis provides extensive research in this area and highlights the limitations of widely applied practices. These practices have limited significance on fundamental engineering principles and become impracticable when a constraint such as a fixed budget is applied – this is the current reality of UK rail network operations and risk management. This thesis identifies three main areas of weaknesses to achieving the desired objectives with current risk reduction methods as: Inaccurate, and unclear problem definition; Option evaluation and selection removed from implementation subsequently resulting in misrepresentation of risks and costs; Use of concepts and methods that are not based on fundamental engineering principles, not verifiable and with resultant sub-optimal solutions. Although not solely intended for a single industrial sector, this thesis focuses on guiding the railway risk decision-maker by providing clear categorisation of measures used on railways for risk reduction. This thesis establishes a novel understanding of risk reduction measures’ application limitations and respective strengths. This is achieved by applying ‘key generic engineering principles’ to measures employed for risk reduction. A comprehensive study of their preventive and protective capability in different configurations is presented. Subsequently, the fundamental understanding of risk reduction measures and their railway applications, the ‘cost-of-failure’ (CoF), ‘risk reduction readiness’ (RRR), ‘design-operationalprocedural-technical’ (DOPT) concepts are developed for rational and cost-effective risk reduction. These concepts are shown to be particularly relevant to cases where blind applications of economic and mathematical theories are misleading and detrimental to engineering risk management. The case for successfully implementing this framework for maximum risk reduction within a fixed budget is further strengthened by applying, for the first time in railway risk reduction applications, the dynamic programming technique based on practical railway examples

    COLLABORATIVE MULTI-SCALE 3D CITY AND INFRASTRUCTURE MODELING AND SIMULATION

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    Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

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    This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski, Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy), Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy

    Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

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    This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process

    Development of a maintenance possession scheduler for a railway

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    Thesis (MEng)--Stellenbosch University, 2022.ENGLISH SUMMARY: Maintenance of rail infrastructure is an important element in rail operations in order to keep tra c moving. However, maintenance causes infrastructure to be taken out of service, which impacts tra c ow. In this study, the requirements of a maintenance possession scheduler for a South African application was investigated, and a proposed solution was subsequently developed. The main objective of the scheduler was to minimise the deviation of the train service on a subset of rail infrastructure while ensuring that the required maintenance is done. To achieve this, a literature study was done on a number of themes, which include an overview of the local railway operator with a look at the role of industrial engineering as a function in the railway operator business, railway infrastructure and operations, planning of railway operations, and maintenance in the context of rail operations. The topic of possession scheduling was then studied; the previous themes helped the researcher to learn the bigger picture while understanding possession scheduling is critical for this study. Past and recent works were studied and research areas and trends were synthesised, including time span of possession scheduling in optimisation models, and whether it was done on microscopic, mesoscopic or macroscopic level. The various optimisation objectives formulated by researchers were also noted, among other subthemes. An application case was identi ed as the railway infrastructure between Bellville and Wellington in the Western Cape province of South Africa. A novel mixed-integer linear programming model was formulated for this case and implemented in Cplex, after which it was validated. The model can do possession scheduling for 24 hours on a microscopic level. Finally, several experiments were conducted to investigate the performance and results of the model. It was found that the model delivered optimal results in less than eight minutes, which makes it a feasible maintenance possession scheduler for day-to-day work in the immediate planning horizon.AFRIKAANS OPSOMMING: Instandhouding van spoorinfrastruktuur is 'n belangrike element in spoorwegoperasies ten einde verkeervloei te verseker. Instandhouding veroorsaak egter dat infrastruktuur uit diens geneem word wat verkeer weer belemmer. In hierdie studie was die vereistes van 'n besitskeduleerder vir instandhouding vir 'n Suid-Afrikaanse toepassing ondersoek, en die voorgestelde oplossing was daarna ontwikkel. Die hoofdoelwit van die skeduleerder was om die afwykings van die trein diens te minimeer op 'n gedeelte van spoorinfrastruktuur terwyl verseker word dat die nodige instandhouding gedoen word. Om dit te bereik is 'n literatuurstudie op 'n aantal temas gedoen. Dit sluit in 'n oorsig van die plaaslike spoorwegoperateur en die rol wat bedryfsingenieurswese as funksie daarin vervul, spoorweginfrastruktuur en operasies, en instandhouding in die konteks van spoorwegoperasies. Die onderwerp van besitskedulering was daarna bestudeer; die vorige temas het die navorser gehelp om die groter prentjie te verstaan, terwyl die studie van besitskedulering kritiek was vir hierdie studie. Navorsingswerk uit die verlede asook onlangse werk was bestudeer en navorsingsareas en tendense is deur sintese bepaal. Dit sluit in die tydsduur van besitskedulering in optimeringsmodelle en of dit op mikro-, meso- of makroskopiese vlak gedoen word. Die verskillende optimeringsdoelwitte wat navorsers formuleer het is ook waargeneem, asook met ander subtemas. 'n Gevallestudie vir toepassing van 'n besitskeduleerder vir instandhouding is identi seer as die spoorweginfrastruktuur tussen Bellville enWellington in die Wes-Kaap provinsie van Suid-Afrika. 'n Nuwe gemengde heeltal-line^ere programmeringmodel was geformuleer vir hierdie gevallestudie en in Cplex implementeer, waarna dit gevalideer is. Die model kan besitskedulering vir 24 uur doen op mikrovlak. Verskeie eksperimente is uiteindelik uitgevoer om die prestasie en resultate van die model waar te neem. Dit is bevind dat die model optimale resultate in minder as agt minute kon lewer, wat dit 'n aanvaarbare instandhouding besitskeduleerder maak vir dag-tot-dag werk in die nabye beplanningshorison.Master
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