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

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.6
• /
• pp.1103-1107
• /
• 2016

The automatic tensioning device of the catenary system constantly maintains the tension of the trolley wire by absorbing the variations due to the elasticity of the line caused by temperature variation. The tension plays an important role in affecting the electric motorcar operation directly. This paper suggests the methodology of the life cycle extension and the maintenance of the automatic tensioning device by means of performance diagnosis of the pulley type automatic tensioning device which has been commonly used for the electric railway system. Through conducting performance diagnosis and comparative test for the wornout pulley type automatic tensioning device by replacing the components such as the bearing and the bearing shaft without replacing all the assembly, the tensioning device is analyzed whether it is properly functioned. Provided that the maintenance regulation is reinforced so as to implement the bearing replacement through periodical precise inspection along with random check-up inspection which is now carried out by the operating organizations, it is ensured that the life cycle extension and the reduction of maintenance cost of the tensioning device could be achieved.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.358-364
• /
• 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
• /
• v.13 no.6
• /
• pp.608-616
• /
• 2010

Seoul Metropolitan Rapid Transit Corporation, managing the line number 5,6,7 and 8 has inspected and maintained for the maintenance of the facilities spread in the extended 152km and 148 stations. Despite the thorough inspection for prevention of the facility failure, the failure has continuously occurred, due to the environmental factors of the underground, mechanical worn-out caused by frequent use, aging facilities, system error, negligence on use, etc. We have achieved a 53.4% reduction in the number of failure by the end of June, 2010 by breaking the conventional way of inspections and maintenance and by adopting quantitative goal management and new way of work. In this paper, we will analyze the problems of inspections and maintenance of the railway facilities, the failure reduction strategy and the performance of each strategy.

• Journal of the Korean Society for Railway
• /
• v.18 no.1
• /
• pp.43-52
• /
• 2015

In this study, to minimize both the costs associated with track maintenance and the energy consumption for train operation, a numerical method that evaluates the optimal vertical stiffness of a fastener for concrete track is presented. A progress model of the track damage is established in order to calculate the concrete track maintenance cost according to the fastener stiffness. Also, the quantitative relationship between the progress of the track damage and the maintenance of the concrete track is derived. The wheel load is more exactly evaluated by using the advanced vehicle-track interaction model, which can precisely consider the behaviors of the track components. An optimal range for the stiffness of the fastener, a range that is applicable to the design of concrete track for domestic high speed lines, is proposed.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.2
• /
• pp.110-121
• /
• 2016

In the decision-making, such as selection of structure, construction method, or time and scheme of maintenance, the evaluation of life-cycle cost(LCC) is of great importance. The maintenance cost occupy a large portion of the LCC of the railway track as well as the initial construction cost. Futhermore, the proportion of the maintenance cost is much higher in the ballasted track. Thus, the importance of the LCC evaluation is higher than in any other engineering structures. In this study, a LCC model that can consider various design parameters such as the type of track structure, annual traffic volume, axle load, train speed, and proportion of curve sections and engineering structures has been developed. Fundamental data for calculating costs also have been presented. Based on the model and data proposed, the trends in the variation of LCC according to the design parameters were examined and the most important design parameters in the LCC analysis of railway track were investigated. The results show that the proportion of renewal and operational costs is much higher in the ballasted track than in the concrete track, and the annual traffic volume and ballast taming period are most significant factors on the LCC of the ballasted track. On the contrary, it is revealed that the proportion of the initial construction costs in the concrete track is much higher, and the LCC of the concrete track is less sensitive to the traffic volume, train speed, and axle load.

• Journal of the Korean Society for Railway
• /
• v.12 no.1
• /
• pp.88-94
• /
• 2009

Life cycle costing is one of the most effective approaches for the cost analysis of long-life products such as the railroad vehicle. Life cycle costing includes the cost of concept design, development, manufacture, operation, maintenance and disposal. Especially, life cycle costing in the railroad industry has been focused on the maintenance cost. In this paper, the standard, guide and maintenance information of railroad vehicle were investigated, and the unique corrective and preventive maintenance templates of railroad vehicle were proposed. Maintenance cost of an auxiliary power supply system of EMU was predicted by using the proposed templates. The results show that the preventive maintenance, PM, cost is much higher compare to corrective maintenance, CM, cost because of daily and monthly maintenance tasks which require lots of labor work. It is expected that these templates can help railroad operators make maintenance strategies with consideration of the cost parameter.

• Structural Engineering and Mechanics
• /
• v.46 no.4
• /
• pp.571-594
• /
• 2013

Railway truss bridges are amongst the essential structures in railway transportation. Minimization of the construction and maintenance costs of these trusses can effectively reduce investments in railway industries. In case of railway bridges, due to high ratio of the live load to the dead load, the moving load has considerable influence on the bridge dynamics. In this paper, optimization of the railway truss bridges under moving load is taken into consideration. The appropriate algorithm namely Hyper-sphere algorithm is used for this multifaceted problem. Through optimization the efficiency of the method successfully raised about 5 percent, compared with similar algorithms. The proposed optimization carried out on several typical railway trusses. The influences of buckling, deformation constraints, and the optimum height of each type of truss, assessed using a simple approximation method.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.713-718
• /
• 2007

This paper is described the System of effective RAMS Management established for AREX Railway System. This system for AREX's E&M system contains FRACAS(Failure Reporting, Analysis and Corrective Action Plan) and computation of RAMS indices. This procedure is applying to improve the Reliability, Availability, Maintainability and Safety for railway system in operation stage. Furthermore, this system would be a basis of RCM(Reliability Centred Maintenance).

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1046-1051
• /
• 2004

As a method to execute efficient maintenance of steel railway bridge, in this paper, program for fatigue assessments of structural member of steel railway bridge were developed. This program is composed with 3 unit module program which variable stress analysis, fatigue assessment and fatigue crack propagation. The validity of developed program was verified from evaluating the result of filed measurement and program output.