• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.130-137
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• 2018

In long freight trains, there is a brake time delay in the neighboring freight cars that causes damage and fractures of couplers, especially the knuckle of them. If there is a problem for couplers in the cars, this could cause a derailment and lead to damage of human life and property damage. In this study, maximum forces on the couplers are studied when a long freight car brakes, with brake delay time and coupler gap. We have made a dynamic model of 50 freight cars and couplers, applying contact between couplers and a characteristic curve for expressing force and displacement of buffers with SIMPACK, a multi-body dynamics program. We use EN 14531-2 from the British Standards Institution, a standard of freight car brakes for the verification of the dynamic model. We also use a simplified method to analyze the dynamic model of 50 freight cars. With changing coupler gap and brake delay time, we do comparative analysis with AAR M-201 from the Association of American Railroads, a standard of AAR couplers. From this result, we find that the standard on fatigue limit is satisfied, such that the brake delay time is within 0.06 second if the coupler gap of the AAR coupler is within 20 millimeters.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.65-72
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• 2019

In long freight trains, there is a brake time delay in neighboring freight cars, which causes damage and fractures in the couplers, especially at their knuckle. A problem in the couplers of the cars can cause derailment and damages of human life and property. In this study, maximum forces on the couplers are studied when a long freight car brakes with the brake delay time and coupler gap. We make a dynamic model of 50 freight cars and couplers, applying contact between the couplers and a characteristic curve to express the force and displacement of the buffers using SIMPACK, which is a multi-body dynamics program. We use EN 14531-2, which is a standard of freight car brakes, to verify the dynamic model. Then, we compare the analyzed impact force with the coupler knuckle standard after applying the two carriages of a locomotive in the model based on the dispersed double head control system. The result shows that all coupler gap conditions satisfy the infinite lifetime of the material when the brake delay time is 0.1 second.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.138-143
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• 2013

Recently, the demand for rail freight has gradually decreased. In particular, the demand in Korea for open freight cars, which classification includes gondola cars, hopper cars and gravel cars has been significantly reduced. The role of gondola cars in the rail transportation market shrank to 14.5% in 2010 from 23.3% in 2001. The transportation demand of gondola cars in the long term is expected to be reduced further. Because some gondola cars have been converted to container cars and various containers are being developed to transport bulk cargo by container cars. However, gondola cars still play an important role in rail freight transport. Therefore, the management planning of gondola cars is needed in order to prepare for the long-term declining demand. In this study, we propose a future direction for the management planning of gondola cars through the effectiveness analysis of gondola cars operation.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.280-285
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• 2003

The process of railway traffic planning is composed of several steps such as long-term, mid-term. short-term, and real-time plan. The planning of vehicle and manpower resources is a main research topic in tactical short-term planning step. Railway vehicle is usually consisted of a power car, passenger/freight cars and human resource is composed of engine driver, cabin crew, ground personnel. So far, power car was main research target in railway vehicle scheduling problem. Recently according as the light electric railway or high-speed railway is introduced, the operational planning of trainset vehicles become important, In this paper, we introduce the conceptional model for trainset restoring problem and developed heuristic algorithm.

• Proceedings of the Safety Management and Science Conference
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• 2003.05a
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• pp.53-61
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• 2003

The process of railway traffic planning is composed of several steps such as long - term, mid - term, short - term, and real - time plan. The planning of vehicle and manpower resources is a main research topic in tactical short - term planning step Railway vehicle is usually consisted of a power car, passenger/freight cars and human resource is composed of engine driver, cabin crew, ground personnel. So far , power car was main research target in railway vehicle scheduling problem. Recently according as the light electric railway or high - speed railway is introduced, the operational planning of train set vehicles become important . In this paper , we introduce the conceptional model for trainset restoring problem and developed heuristic algorithm.