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Railway System (railway + system)
Selected AbstractsEnergy Saving and Environmental Measures in Railway Technologies: Example with Hybrid Electric Railway VehiclesIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 1 2008Masamichi Ogasa Member Abstract The electric railway system is the highest class of energy efficient transportation means. This is due to two important points: (i) low running resistance (including low energy losses) and (ii) energy regeneration in braking. Regenerative braking of railway electric vehicles is effective when the other powering ones, in other words electrical load, exist near the regenerating train on the same electrified line. So, early in the morning and at midnight, or in the low-density district lines, regeneration cancellation phenomenon often occurs and the regenerative brake force cannot be operated in accordance with the recommended value. Newly appeared high-performance energy storage devices press the issues of energy storage and reuse technologies on ground and on vehicles. Hybrid energy source is one effective solution. In this paper, as an example, we show our trolley and on-board battery hybrid controlled tramcar, developed to reduce regeneration cancellation. With the trolley line collective power as well as charge and discharge power of the on-board lithium ion rechargeable battery, the hybrid energy providing and regenerating technology is achieved. The running test results show a maximum regenerative ratio of 44%, which is top class value in an electric railway system. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Network service scheduling and routingINTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 6 2004G. Groves Abstract Real-life vehicle routing problems generally have both routing and scheduling aspects to consider. Although this fact is well acknowledged, few heuristic methods exist that address both these complicated aspects simultaneously. We present a graph theoretic heuristic to determine an efficient service route for a single service vehicle through a transportation network that requires a subset of its edges to be serviced, each a specified (potentially different) number of times. The times at which each of these edges are to be serviced should additionally be as evenly spaced over the scheduling time window as possible, thus introducing a scheduling consideration to the problem. Our heuristic is based on the tabu search method, used in conjunction with various well-known graph theoretic algorithms, such as those of Floyd (for determining shortest routes) and Frederickson (for solving the rural postman problem). This heuristic forms the backbone of a decision support system that prompts the user for certain parameters from the physical situation (such as the service frequencies and travel times for each network link as well as bounds in terms of acceptability of results) after which a service routing schedule is suggested as output. The decision support system is applied to a special case study, where a service routing schedule is sought for the South African national railway system by Spoornet (the semi-privatised South African national railways authority and service provider) as part of their rationalisation effort, in order to remain a lucrative company. [source] Remapping German-Jewish Studies: Benjamin, Cartography, ModernityTHE GERMAN QUARTERLY, Issue 3 2009Todd Presner By examining the entangled places of encounter, exchange, and contamination between German and Jewish, this article argues that German modernity and Jewish modernity are deeply, precariously, and indissociably intertwined. Drawing on its methodology from the field of "mobility studies" (the study of bodies moving through spaces), I argue that we must interrogate the medium in which cultural history is composed and turn our attention to the visualization of narratives of movement, dislocation, and dispersal. I look to Walter Benjamin's urban reflections, the history of modern cartography, the emergence of the railway system, and a web-based mapping project called "HyperCities" in order to show how the history of German/Jewish modernity might be mapped as layered networks and sites of encounter. [source] Optimization of Train Speed Profile for Minimum Energy ConsumptionIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2010Masafumi Miyatake Member Abstract The optimal operation of railway systems minimizing total energy consumption is discussed in this paper. Firstly, some measures of finding energy-saving train speed profiles are outlined. After the characteristics that should be considered in optimizing train operation are clarified, complete optimization based on optimal control theory is reviewed. Their basic formulations are summarized taking into account most of the difficult characteristics peculiar to railway systems. Three methods of solving the formulation, dynamic programming (DP), gradient method, and sequential quadratic programming (SQP), are introduced. The last two methods can also control the state of charge (SOC) of the energy storage devices. By showing some numerical results of simulations, the significance of solving not only optimal speed profiles but also optimal SOC profiles of energy storage are emphasized, because the numerical results are beyond the conventional qualitative studies. Future scope for applying the methods to real-time optimal control is also mentioned. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Effect of metallised carbon content of collector strip on the wear of contact wire,collector strip pair in railway systemsLUBRICATION SCIENCE, Issue 1 2007B. Pizzigoni Abstract Among the topics related to the interaction between the contact wire of the overhead line and the collector strip, the wear that takes place at the contact interface, depending on both electrical and mechanical quantities, represents an important aspect of maintenance costs, affecting the mean lifetime of collectors, in terms of travelled kilometers (in terms of tenth of thousands), and contact line duration, in terms of years (between 15 and 40). Due to its importance in the global maintenance of both rolling stock and infrastructure, this topic deserved the attention of several regulations in the last decade. In order to investigate the effects of electro-mechanical wear on both contact wire and contact strip, a new test equipment has been designed and installed at Politecnico di Milano. A series of tests have been performed, involving different kinds of collector strip materials and contact conditions, tested at varying speeds and current intensities. This investigation concerned different collector strip configurations intended for 3kV D.C. lines. The combination of different contents of copper and metallised carbon in the collector has been found to influence the wear rate of both collector strip and contact wire. Differences in wear up to four times for the former and up to six times for the latter have been found depending on the composition of the collector. Copyright © 2006 John Wiley & Sons, Ltd. [source] Personnel Discipline and Industrial Relations on the Railways of Republican ChinaAUSTRALIAN JOURNAL OF POLITICS AND HISTORY, Issue 1 2001Stephen L. Morgan The Chinese National Railways of Republican China (1912-37) had a personnel administration the equal of any of the major railway systems of the period. Railways require a sophisticated personnel bureaucracy to train, monitor and enforce codes of conduct which would ensure the safety of passengers, freight and the huge investment in rolling stock and fixed capital. Only the military had previously administrative structures approaching the modern railway companies, the first modern business to organise on such a scale large numbers of employees over vast geographic areas. In China the railway introduced not only a new transport technology but also played a major role in creating the new industrial working class through the regimes of work and discipline their administration created. Drawing on neglected railway personnel archives, this paper examines the work organisation and structures of discipline that governed the working day of Chinese railway employees. [source] | |||||||||||||