• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1126-1131
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• 2006

Risk assessment of a railway system should be periodically conducted managing a large amount of accumulating accident/incident data and scenarios, which generally requires enormous time and efforts. Therefore, special information management system is essential for railway risk assessment, where data needed for decisions on managing the railway safety could be promptly supported. The objective of this study is to develop a railway accident analysis program for risk assessment. The program is application running on the web which links railway accident analysts throughout the railway industry to a central database. Data entered, together with associated code tables. is stored on MS-SQL database. The program uses the concepts of accident, safety events, causes, related factors(vehicle, person, infrastructure, tool/equipment), recommendations to bring together the various elements of railway accidents. The program will be useful in finding hazard conditions, accident scenarios, quantitatively assessing the risk, and providing pertinent risk measures, eventually serving to prevent railway accidents and reduce severities of railway accidents.

• International Journal of Railway
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• v.1 no.4
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• pp.157-168
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• 2008

The creation of a single European rail transport market it is important to increase confidence between the actors on the market and between member states who shall ensure that railway safety is generally maintained and, where reasonably practicable, continuously improved. For this purpose the European railway safety directive introduces a mechanism to adopt a Common Safety Targets (CST) expressed in risk acceptance criteria for individuals and for society. This paper focuses on the apportionment of safety targets for European railway system. We develop a generic approach based on the Functional Hazard Analysis (FHA), to analyse the safety of railway systems for a unified European network and to comply with the CSTs required by the European railway Safety Directive. We suggest to combine the FHA technique with the functional railway architecture to allocate the safety targets to the railway functions.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.70-78
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• 2014

Recently, the Korean government is considering a policy of adopting competition in railway transportation, such as the establishment of a subsidiary company to Korail as a company to operate a part of the KTX line, the separation of deficit-running lines of local railways and the opening of railway transportation to private operators. The termination of local railway service, which is a major provider of public transportation, will not only deprive the public of a means of transportation but also lead to a decline in the quality of public transit in general. The termination of local railway service is being decisively affected by the national railway policy. The purpose of this thesis is to clarify local railway policy in Japan by studying the development and philosophy of the local railway policy of the Japanese National Railway (JNR).

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1940-1945
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• 2007

The wheelsets are one of most important component: damages in wheel tread and press fitted axle are a significant cost for railway industry. Since failure in railway wheelset can cause a disaster, regular inspection of defects in wheels and axles are mandatory. Ultrasonic testing, acoustic emission and eddy current testing method and so on regularly check railway wheelset in service. However, it is difficult to use this method because of its high viscosity and because its sensitivity is affected by temperature. Also, due to noise echoes it is difficult to detect defects initiation clearly with ultrasonic testing. It is necessary to develop a non-destructive technique that is superior to conventional NDT techniques in order to ensure the safety of railway wheelset. In the present paper, the new NDT technique is applied to the detection of surface defects for railway wheelset. To detect the defects for railway wheelset, the sensor for defect detection is optimized and the tests are carried out with respect to surface and internal defects each other. The results show that the surface crack depth of 1.5 mm in press fitted axle and internal crack in wheel could be detected by using the new method. The ICFPD method is useful to detect the defect that initiated in the tread of railway wheelset.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.331-340
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• 2009

This study is objected by suggesting rationalization method of management and maintenance cost for railway investment assessment. The estimate of rational benefit and cost are a work of vital importance to decide railway investment as preliminary feasibility investigation is institutionally reinforced since January 2007. In particular, railway management and maintenance cost have to be applied to realistic and detail cost as railway investment assessment guide. For example, types of railway, construction of new line, improvement of conventional line, double tracking, railway electrification. However, railway investment assessment is inconsistency because of estimating the railway management and maintenance cost using existing unrealistic management and maintenance cost. Therefore, this study is performed parametric analysis effecting on the railway management and maintenance cost considered new technique, enhanced facilities and improved standard. Also, it suggests the itemized standard management and maintenance cost. Finally, it will be helped to establish the base of railway investment through the rationalization method of management and maintenance cost.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.409-417
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• 2009

This paper is focused on a relationship between the noise and vibration of a wheelset and the railway irregularity of a high speed railway using a time-varying frequency transform for a preliminary research of the railway condition monitoring by an in-service high-speed railway vehicle. Generally, the monitoring has been performed by a special railway inspection vehicle or industrial engineers for railway maintenance. However, they have been limited at night due to the in-service high-speed railway vehicles, and too slow to monitor all of the section. To solve this problem, the monitoring should be performed by an in-service high-speed railway vehicle. For the research, the noise and vibration of a wheelset are utilized, because they are closely related to the railway condition. They are measured by using some microphones and accelerometers, and stored in an on-board data acquisition system. The signals are post-processed by a time-varying frequency analysis and compared with the result of a railway geometry and profile measurement system. From the comparison, it is able to observe the relationship between the noise and vibration of a wheelset and the irregularity of a high-speed railway. Also, some distinct frequency components are observed, which are not observed in the railway geometry and profile.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.193-198
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• 2012

As a result of investment in railway safety since 2004, railway accidents have been reduced by half and we reached a high level of safety compared to other countries. But people are still worries about railway accident, and want safer railway. It is difficult to determine which level of safety must be achieved due to lack of comparative studies on railway safety among different countries and other transportation modes. In this study, a comparative study on railway accident statistics and various transportation modes is performed. The results of this research can be used for the determination of weak areas of railway safety and the level of safety to be achieved.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.38
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• pp.1-6
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• 2007

Railway wheels in service are regularly checked by ultrasonic testing, acoustic emission and eddy current testing method and so on. However, ultrasonic testing is sometimes inadequate for sensitively detecting the cracks in railway wheel which is mainly because of the fact of crack closure. Recently, many researchers have actively fried to improve precision for defect detection of railway wheel. The development of a nondestructive measurement tool for wheel defects and its use for the maintenance of railway wheels would be useful to prevent wheel failure. The induced current focusing potential drop(ICFPD) technique is a new non-destructive tasting technique that can detect defects in railway wheels by applying on electro-magnetic field and potential drops variation. In the present paper, the ICFPD technique is applied to the detection of surface and internal defects for railway wheels. To defect the defects for railway wheels, the sensor for ICFPD is optimized and the tests are carried out with respect to 4 surface defects and 6 internal defects each other. The results show that the surface crack depth of 0.5 mm and internal crack depth of 0.7 mm in wheel tread could be detected by using this method. The ICFPB method is useful to detect the defect that initiated in the tread of railway wheels

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1101-1104
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• 2005

The overall objectives for Korean railway system of the future are speedup, capacity management, increase safety, environmental protection. and enhancement efficiency. To achieve these, interconnection within the railway system must be optimised and designed on a customer-friendly basis. This principles applies to both passenger and freight traffic. for which cost-effective and time-efficient facilities must be provided. As the result. Korean railway network modernization is based on seeking out optimum conditions for improving railway business.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.252-257
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• 2005

As the Korea Railroad (KR) was privatized at the beginning of 2005, the Korean Railway Standards (KRS), which was managed previously by KR, have been managed by the Korean Ministry of Construction and Transportation. According to Railway Safety Law and ordinances, which are for the guarantee of safety in railway applications, the management of KRS including enactment and revision of technical standards for railway vehicle and components, was committed to Korea Railroad Research Institute. In this investigation, the detailed management plan and contents are introduced for the effective management of KRS.