• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.555-560
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• 2006

This study finds out and suggests success factors for the application of RIMS project through the case study of Seoul Metro and literature survey. The successful application of RIMS needs expert knowledge and concept of BOM, standardization of maintenance planning, check lists of heavy maintenance inspection, organization structure of rolling stock maintenance offices, material management system of warehousing and the process of parts repairing between offices, connection of material ordering system, problem solving of circular spare parts administration among inspection, maintenance, and material organizational units, systemic serial number management of parts with RFID, daily closing diary connected with work process chart, and sufficient period of RIMS's test run. RIMS contributes to real time management of rolling stock maintenance, transparency of management, reliability of train operation, customer satisfaction, and management innovation.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1864-1870
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• 2007

The inspection periods for the metro EMU maintenances vary variously according to the countries and railway operators. And the inspection systems vary according to the safety, economical, technical aspects, and also the social environments like passengers and maintenance qualities, etc. Also, in economic point of view, maintenance requires the man power, facilities, equipments, purchasing of parts and the loss of not being in revenue service during the maintenance period. Recently, there is a tendency that the inspection periods are extended gradually owing to the increased reliabilities of the equipments and parts of EMUs. Even if it is the EMUs that are already be in service, once the inspection method is innovated, the inspection time can be reduced. The inspection management innovation scheme includes such methods as the complete module to module replacement when trouble shooting a faulty parts before putting the EMU back to revenue service, the replacements of parts in complete set unit for the heavy maintenance, the establishments of exchange periods for the wasting parts, modernization of inspection equipments, introduction of RAMS for the reliability improvement and computerization of EMU maintenance management, etc. I think it is possible to optimize the inspection scopes and periods per parts and equipments by the introduction of RAMS.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.378-382
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• 2005

The opening of high speed railway upgraded our land transportation speed limit, causing lots of changes including living and culture and also paving the way for stepping up the railway technology. However, it is also true that we had a limit to adopt the existing railway system structured for 150km/h to the new structure requiring a higher speed of approximate 300km/h due to technological, based on the time and experience. More importantly, heading toward a step of operating such a high speed railway system, it has been practically and quickly proposed that the railway needs high speed railway engineering, maintenance technology of parts of the vehicles to have a stable maintenance foundation and localization of major parts. Therefore, this study was intended to research the actual displacement characteristics in runningg on an actual track for the purpose of developing the protective and maintenance technology of springs and dampers, which are core parts among suspension elements of a high speed railway vehicle. For this, it was researched the actual vehicle test and its interpretation centered on primary spring, which is used for the suspension system of a bogie, body-body dampers and body-bogie yaw damper. Also, to analyze the displacement characteristics of suspension system in the actual conditions of high speed railway vehicles, a vehicle‘s dynamic characteristics was analyzed and interpreted. At the same time, a tester for measuring the actual displacement of such suspension elements was designed and attached to actual vehicles, to measure the displacements that occur in running it on the Seoul-Busan line, one of major lines serviced by KTX. The displacement data gained from the test with actual vehicles was analyzed for its displacement distribution depending on the service sections and frequency, with which the valuable data necessary for any potential breakdown or maintenance in the future could be obtained.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.566-571
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• 2012

The door systems in urban railway vehicles, through heavy maintenance checks by six years, 75 parts for 34 part types in 75 units have to be replaced periodically, and the remaining 68 parts for 40 part types to be replaced occasionally based on the necessity. Even though this process makes the door systems almost to be initial status, the systems have complicated mixes of components with new parts and used and then have different property from the original ones. This study suggested a burn-in test as a subsidiary tool to improve the reliability of urban railway vehicles, and suitable for testing conditions and the proposed new target value.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.358-364
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• 2004

The standardization of the urban transit maintenance system consists of BOM System, maintenance parts code system, and accident/trouble code system standardization. This paper is described only the result of BOM System, maintenance parts code system, and accident/trouble code system standardization. The results of standardization are using urban transit maintenance IT system and apply Expert System, RAMS System, and DATABASE contents of various kinds.

• Journal of the Korean Society for Railway
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• v.4 no.4
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• pp.138-146
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• 2001

For the purpose of the effective maintenance of surface irregularities of rail, this paper investigates the rail service life to a bending fatigue failure of welding parts of rail on the slab track by the structures laboratory testing to derive S-N curves, a GTDAP(General Track Dynamic Analysis Program) to calculate the stresses and a modified Miner's rule to predict a fatigue life. The useful guides for maintenance of rail welded parts on the slab track are proposed in terms of a grinding period and the depth of rail surface irregularities. This study also proposed the guides for maintenance of rail welded part on the ballast track. The effects of fatigue service lives are compared one another.

• International Journal of Railway
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• v.9 no.1
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• pp.10-14
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• 2016

Life cycle cost analysis is compulsively required for the system operation. System operation costs are consisted of acquisition, operation, maintenance and so on. In the beginning of the system planning, we need to take into account of various costs following the system operating. To implement LCC, we need to analyze system life cycle to identify all costs during system life. The costs can be divided into three parts. The first part is purchasing cost, the second for operating cost and the last for disposal cost. The second operating cost can be decomposed of operating cost included labor, energy consumption cost for system running, maintenance costs to keep systems healthy, delay cost caused from maintenance and hazard cost, and so on. In this paper, we carried out for railway locomotives which operate over more 30years and which cost about 10 million USD. We decompose the life cycle of the locomotives and break down the locomotives into subsystems to require maintenance or not, and subsystems to need energy or not. We showed how to decide optimal locomotives through cost identification and system breakdown.

• Journal of the Korean Society of Systems Engineering
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• v.18 no.1
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• pp.1-13
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• 2022

The Yongin Light Rail train was manufactured by Bombardier Transportation in Canada in 2008 and is a privately invested railway line that has been operating in Yongin-si, Gyeonggi-do, since 2013. When the frequency of train failure increases due to aging, and there is a delay in the delivery period of imported parts used in the Bombardier manufactured trains, timely vehicle maintenance may not be performed due to lack of parts. To solve this problem, it is necessary to build a 'vehicle parts maintenance demand forecasting system' that analyzes the accurate and actual maintenance demand annual based on the condition of vehicle parts. The full scope of analysis in this paper analyzes failure data from various angles after opening of Yongin light rail vehicle to analyze failure patterns for each part and identify replacement cycles according to possible failures and consumption of parts. Based on this study, it is expected that Yongin Light Rail's maintenance system will change from the existing time-based replacement (TBM) concept to the condition-based maintenance (CBM) concept. It is expected that this study will improve the efficiency of the Yongin Light Rail maintenance system and increase vehicle availability. This paper is a fundamental for establishing of a system for predicting the replacement timing of vehicle parts for Yongin Light Rail. It reports the results of data analysis on some vehicle parts.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.23-26
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• 2011

The efficiency and performance of electric facilities in electric railway tunnels are quite important factors for operation and maintenance of railway since most of maintenance works for railways are doing during the night. Specially, in the railways like Gyeong-Chun Line passing through many mountains, many parts of railways are constructed with tunnels. So, this paper proposes the efficient electrical installation design scheme for railway tunnel considering the system performance, economics, and the reliability of power supply to tunnel electric facilities. Finally, the proposed design scheme is implemented to the tunnel design for Gyeong-Chun Line (Electric Railway).

• Geomechanics and Engineering
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• v.14 no.6
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• pp.563-570
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• 2018

Ballast layer has an important role in vertical stiffness and stability of railway track. In most of the Middle East countries and some of the Asian ones, significant parts of railway lines pass through desert areas where the track (particularly ballast layer) is contaminated with sands. Despite considerable number of derailments reported in the sand contaminated tracks, there is a lack of sufficient studies on the influences of sand contamination on the ballast vertical stiffness as the main indicator of track stability. Addressing this limitation, the effects of sand contamination on the mechanical behavior of ballast were experimentally investigated. For this purpose, laboratory tests (plate load test) on ballast samples with different levels of sand contamination were carried out. The results obtained were analyzed leading to derive mathematical expressions for the strain modulus ($E_V$) as a function of the ballast level of contamination. The $E_V$ was used as an index for evaluation of the load-deformation characteristics and bearing capacity of track substructure. The critical limit of sand contamination, after which the $E_V$ of the ballast reduces drastically, was obtained. It was shown that the obtained research results improve the current track maintenance approach by providing key guides for the optimization of ballast maintenance planning (the timing of ballast cleaning or renewal).