3,326 research outputs found

    Alternate Double Single Track Lines

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    [EN] The paper discusses the advantages and shortcomings of alternate double single track (ADST) lines with respect to double track lines for high speed lines. ADST lines consists of sequences of double and single track segments optimally selected in order to reduce the construction and maintenance costs of railway lines and to optimize the timetables used to satisfy a given demand. The single tracks are selected to coincide with expensive segments (tunnels and viaducts) and the double tracks are chosen to coincide with flat areas and only where they are necessary. At the same time, departure times are adjusted for trains to cross at the cheap double track segments. This alternative can be used for new lines and also for existing conventional lines where some new tracks are to be constructed to reduce travel time (increase speed). The ADST proposal is illustrated with some examples of both types (new lines and where conventional lines exist), including the Palencia-Santander, the Santiago-Valparaíso-Viña del Mar and the Dublin-Belfast lines, where very important reductions (90 %) are obtained, especially where a railway infrastructure already exist.Moraga Contreras, P.; Grande Andrade, Z.; Castillo Ron, E. (2016). Alternate Double Single Track Lines. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat PolitÚcnica de ValÚncia. 527-536. https://doi.org/10.4995/CIT2016.2015.3426OCS52753

    Probabilistic Safety Analysis of High Speed and Conventional Lines Using Bayesian Networks

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    [EN] A Bayesian network approach is presented for probabilistic safety analysis (PSA) of railway lines. The idea consists of identifying and reproducing all the elements that the train encounters when circulating along a railway line, such as light and speed limit signals, tunnel or viaduct entries or exits, cuttings and embankments, acoustic sounds received in the cabin, curves, switches, etc. In addition, since the human error is very relevant for safety evaluation, the automatic train protection (ATP) systems and the driver behavior and its time evolution are modelled and taken into account to determine the probabilities of human errors. The nodes of the Bayesian network, their links and the associated probability tables are automatically constructed based on the line data that need to be carefully given. The conditional probability tables are reproduced by closed formulas, which facilitate the modelling and the sensitivity analysis. A sorted list of the most dangerous elements in the line is obtained, which permits making decisions about the line safety and programming maintenance operations in order to optimize them and reduce the maintenance costs substantially. The proposed methodology is illustrated by its application to several cases that include real lines such as the Palencia-Santander and the Dublin-Belfast lines.Grande Andrade, Z.; Castillo Ron, E.; Nogal, M.; O'connor, A. (2016). Probabilistic Safety Analysis of High Speed and Conventional Lines Using Bayesian Networks. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat PolitÚcnica de ValÚncia. 362-371. https://doi.org/10.4995/CIT2016.2015.3428OCS36237

    The planned TEN-T railway corridor "Baltic Sea - Black Sea - Aegean Sea" as an opportunity for economic development of Eastern Poland

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    Abstract: The article describes the basic requirements for the railway infrastructure of the comprehensive, extended core and core TEN-T network resulting from the draft of a new regulation of the European Parliament and of the Council (EU) on this matter. Then, the proposed TEN-T corridor “Baltic Sea – Black Sea – Aegean” is presented, which route is to lead largely through eastern and south-eastern Poland. This corridor, along with its considered link with the “Rail Baltica” route, fits well with the concept of the so-called eastern main line. The condition for creation of the corridor and the link is to ensure technical and operational parameters in accordance with the TEN-T requirements on the sections of railway lines included in their route, therefore the article assesses, what scope of investment works is related to the achievement of this goal and what adjustments and optimization measures should be considered. The creation of the corridor with the link may increase the transport accessibility of Polish regions located within their range of influence, and thus contribute to the economic development of these regions. Key words: accessibility, railway infrastructur

    Spartan Daily, May 10, 1982

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    Volume 78, Issue 60https://scholarworks.sjsu.edu/spartandaily/6903/thumbnail.jp

    Introduction to high speed railway services in the Czech Republic

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    Esta tesina pretende ser un estudio sobre la planificaciĂłn de los servicios ferroviarios de alta velocidad en la RepĂșblica Checa, atendiendo tanto a los aspectos constructivos y tecnolĂłgicos de la misma como los aspectos estratĂ©gicos de la fase de estudio, entendiendo por ello el anĂĄlisis de la oferta y la demanda, la afectaciĂłn sobre el territorio y la red actual existente, las relaciones con otros medios de transporte y la conexiĂłn con los paĂ­ses limĂ­trofes. Asimismo, se trata de hacer un anĂĄlisis econĂłmico de la propuesta para estudiar la viabilidad de la inversiĂłn, sin dejar de lado el impacto ambiental que dicha infraestructura ocasionarĂ­a. En todo momento se hace referencia al trĂĄfico de pasajeros y de mercancĂ­as, con objeto de realizar un estudio exhaustivo y completo

    Timetable coordination of first trains in urban railway network: A case study of Beijing

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    A model of timetable coordination of first trains in urban railway networks, based on the importance of lines and transfer stations, is proposed in this paper. A sub-network connection method is developed, and a mathematical programming solver is utilized to solve the suggested model. A simple test network and a real network of Beijing urban railway network are modeled to verify the effectiveness of our suggested model. Results demonstrate that the proposed model is effective in improving the transfer performance in that they reduce the connection time significantly

    Optimisation of automatic train protection systems.

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Garden Cities of the 21st Century

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    It has been more than 100 years since Ebenezer Howard published his epochal book on social reform that ultimately won him world recognition. Published first in 1898 as 'Tomorrow: A Peaceful Path to Real Reform', it was followed by revised publications in 1902, 1946 and 1965 under its present more evocative title, ‘Garden Cities of Tomorrow'. The multiplicity of editions testifies to a continued interest to secure a harmonious existence between humans and their natural environment. Influenced by the conventional wisdom of the time, deviations from the original 1898 publication by Howard of his town plan and his social and financial proposals affected the design and implementation of the prototype city of Letchworth built in 1903. Ignoring the drawings and writings of Howard’s book, the Letchworth model, because it was completed within the lifetime of Howard, was seen and accepted as the de facto model from which future garden cities could be reproduced. Duplication of the Letchworth prototype in Europe and North America, as a result of the deviations, led to incomplete, inaccurate or dysfunctional replications. The Letchworth concept of garden cities must be considered to have failed to reach the goal Howard had hoped to achieve: a distribution of sustainable, benign urban environments with an equitable and wholesome quality of life in a rural setting. More than a full century has elapsed since Howard wrote his book and the world has entered a new millennium. New technologies, changing demographics and, most importantly, emerging social and environmental circumstances raise the possibility that the concept of garden cities could be revisited to determine that, if adapted to meet the constraints and needs of the 21st century, could reach the goals envisaged by Howard. To reach this goal would require a return to the writings and drawings of his original work, 'Tomorrow: A Peaceful Path to Real Reform', and a departure, independent of previous attempts to interpret the content of Howard’s dream for all societies
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