• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1418-1425
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• 2011

Subway operators in the country have their own heavy maintenance facilities for maintaining rolling stock(EMU). However, it is true that the heavy maintenance facilities are not utilized 100% with the recent trend of lengthening maintenance cycle(intervals). With the fact, this enabled the existing maintenance facilities to be utilized for other purposes. By taking advantage of spare facilities and the maintenance staff with rolling stock assembly abilities, subway operators can assemble rolling stock by procuring parts for the assembly instead of purchasing trains from other companies. It is estimated that this will enhance the operator's technology and have a great impact on the management skill as well. This study attempts to find out how the heavy maintenance factory can be utilized for rolling stock assembly.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.322-325
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• 2005

TTX(Tilting Train eXpress) is being designed for improving the speed of conventional railway. The purpose of this study is to evaluate energy absorbing capacity and driver's survivability for a design candidate of the front end structure of TTX. A FE model with honeycomb block, under frame, and body frame is generated for crash simulation. Based on a level-crossing accident scenario, numerical simulation is performed using LS-DYNA. The results of crash analysis show that strength improvement of the current front end structure design candidate is needed to ensure driver safety.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.393-397
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• 2005

Since the braking system of rolling stock is directly linked to it's safety, ensuring reliability of braking system and evaluation of performance of it are very important. To develope the performance of braking system, it is required advanced technology and gradually various factors in the field test result. This study is designed to analyze the air pressure control about braking force in rolling stock, also, by comparing braking force of high speed railway with that of high speed train. This paper suggests to establish a method of computation of braking force form the air pressure control. And The high speed train researches into patterns of braking system such as the train of speed up and introduction of electric and pneumatic braking system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.220-230
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• 2015

Rolling stock RAMS is a field of engineering which integrates reliability, availability, maintainability and safety (RAMS) characteristics into an inherent product design property through rolling stock system engineering process. It is implemented to achieve operational objectives successfully, and recently the RAMS has become a rapidly growing engineering discipline because it has a great potential to ensure safety and improve cost effectiveness. However, the Korean rolling stock industry has not yet implemented RAMS management in the rolling stock engineering process, despite the issue having been addressed since the introduction of the KTX. Thus, this paper discusses the processes, methods and techniques for RAMS assessment in three parts. Firstly, it outlines a process of the overall RAMS performance assessment for achieving technical RAMS design criteria. Secondly, it discusses a process for assessing the operational RAM and allocating the RAM. This paper also proposes a model for assessing safety-based risk management, which includes five analytic techniques for identifying the causes and consequences of a system failure. Finally, a case example is provided for the risk assessment of the pneumatic braking device.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.116-126
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• 2010

The Korean rolling stock safety regulation stipulates that the collision deceleration of a car body should be maintained under average 5g and maximum 7.5g during train collisions. One-dimensional dynamic model of a full rake train, which is made up of nonlinear springs/bars-dampers-masses, is often used to estimate the collision decelerations of car bodies in a basic design stage. By the way, the previous studies have often used some average force-deformation curve for energy absorbing structures in rolling stock. Through this study, we intended to analyse how much the collision deceleration levels are influenced by the initial peak force modeling in the one-dimensional force-deformation curve. The numerical results of the one-dimensional dynamic model for the Korean High-Speed Train show that the initial peak force modeling gives significant effect on the collision deceleration levels. Therefore the peak force modeling of the force-deformation curve should be considered in one-dimensional dynamic model of a full rake train to evaluate the article 16 of the domestic rolling stock safety regulations.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.775-783
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• 2010

The Yong-san rolling stock depot in which KORAIL does the maintenance of PP was required to move to the other place, so there are some disputes how to treat PP rolling stock, that is, early scraping, extending life-span or introduction of intercity EMU, but introducing a new train are very expensive and also very risky, so executed economical analysis for the precision political decision. For the specific analysis, set some scenario, first uses PP to their life span, second, introduces new intercity EMU, third, extends the life-span of PP by rolling stock precision diagnosis. Largely, maintenance cost, operation cost, rolling stock value are used for the economical analysis. This research is the specific case of KORAIL, but this result can be a valuable data in the perspective of operation cost between diesel rolling stock and electric rolling stock.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.489-494
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• 2011

In this paper, a method is proposed to evaluate a number of alternatives for light-weight rolling stock recommended from experts in rolling stock and to decide an optimal alternative. At first, many customer needs from various fields in railroad are drawn and weights of customer needs are decided by AHP. Secondly, technical requirements that should be real specifications for light-weight rolling stock are set and weights of technical requirements are decided by QFD. Finally, we evaluate some proposed alternatives and conclude an optimal alternative of light-weight rolling stock with TOPSIS.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1525-1538
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• 2008

Currently, it has been a fashion to include RAMS of rolling stock in the order for purchasing the rolling stock. However, it's only to suggest a qualitative value or an ideal target without giving or demonstrating actual RAMS target, with only demonstrating passive RAMS by the data provided by the manufacturer. In the case of KTX project of 100 cars of KTX-II contracted in June 2006, their target has been suggested from the previous RAMS application standard and it aimed to achieve the reliability level of equivalent high speed rolling stock. Afterward, as actual KTX-II RAMS Plan and RAMS Demonstration Plan has been prepared and approved, it has been the first problem to secure the reliability and safety in order to introduce the new high speed rolling stock(KTX-II) successfully and we actually tried to apply overseas RAMS standard, KTX samples, electric railcar MTRC and rolling stock samples. This Report was dealt world trends of Railway RAMS standard, KTX-II RAMS Specifications, the present condition of KTX-II RAMS performance and development a way of KTX-II RAMS, We hope the "KTX-II RAMS Application Standard for Safety of Passenger Transportation Service" is served as an opportunity for the basic research for establishing and demonstrating RAMS target of components or parts composing the rolling stock system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.78-87
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• 1999

A mathematical model for the stress free surface profile in Over-Round and Round-Oval grove rolling, which can be used effectively in the calculation of pass area, is presented. The new model has generality, simplicity and accuracy for practical usage. The stress free surface profile of an outgoing stock can be modeled when the maximum spread of it known a priori. The equation for the stress free surface profile is formulated from the linear interpolation of the radius of curvature of an incoming stock and that of roll groove to the axis direction. In developing the analytical model, the effect of rolling temperature and friction between roll and work piece(stock) were not considered since the geometry of roll groove and the incoming work piece were assumed a dominant factor which decides the stress free surface profile of the outgoing stock. A simulation with the analytical model developed also has been carried out to demonstrate the stress free surface profile of the outgoing stock.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.407-415
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• 2001

A case of air pollution study of estimation of emission rate for source to railroad rolling stock and emissive character about is unusual. Recent emission rate of railroad rolling stock was estimated with emission factor of EPA in three region(Seoul, Incheon, and Gyeonggido). But this EPA factor could be incorrect because Korea and America have a different railroad environment in the variety of fuel and character of railroad rolling stock In this study, emission rate of each line, car and region(district) with omission factor of Korean case(National Railroad Administration, 1997) was estimated. In Busan Metropolitan City, railroad rolling stocks were divided accoding to, each line, car and service. Particularly, the Idle fuel rate omitted in the preceding study was included in calculation fuel rate. Total emission rate of Busan Metropolitan City was 887.41 t/year Each emission rates of Kyeongbu line, Donghaenambu line, Gaya line, Uam line, Bujeon line, and idle was 489.15t, 196.46t, 33.94t, 12.66t, 6.47t, and 48.75t, respectively.