• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.55-62
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• 2011

Although the performance of the commercial vessel has been dramatically improved through innovations, there has been no big changes on the traditional anchoring method of commercial vessels, both on design and operation until now. In this paper, two cases of design modifications were introduced for optimized design of pocket type anchor handling, which resulted in improved performance of the vessel's anchoring. From the first time fully balanced type anchors were applied on vessels in Korean shipyard, main design problem on this application was that the anchor doesn't normally slide into the pocket when the anchor fluke is not in line with pocket, as the anchor freely rotates by the swivel on forerunner. In order to prevent the problem, swivel has been deleted on the forerunner to prevent anchor rotation until now, but this solution caused problems such as twist lock of anchor chain, restriction of windlass direction, etc. On this paper, one of the solution is introduced to overcome the design problem by tilting the hawse pipe to some extent, which makes anchor turned at the time anchor ring touches the pocket skirt and that it properly slides into the pocket. Secondly, one of the solution is introduced to overcome misalignment problem between anchor chain cable and roller of chain compressor, which has been frequently occurred, by modification of roller design.

• Journal of Ocean Engineering and Technology
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• v.19 no.5 s.66
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• pp.34-42
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• 2005

The cable connection zone of the cable-stayed bridge transfers deal-load, live-load, and second-load to the cables on the structural joint zone of the cables and the main girders are the most critical parts in which big cable tensile forces are generated by those loads. Therefore, it is necessary to thoroughly check the main girder, structurally to secure the required stability. Because of the heavy tensile force of cables linked in the connection zone of the cable-stayed bridge, locally concentrated stress, as well as the dispersion of stress, occurs in the structurally contacted point of cable and main girder thus, we need to make a thorough investigation through a detailed structural analysis. Directly delivering the tensile force to the connection zone of the cable, the consequently big effect in the tensile force fluctuation caused by the live-load will make it necessary to review the fatigue strength. As the connection zone of the cable is designed to resist the tensile force of the cable, which is applied to a connecting section as a concentrated force, thick plates are used. These plates are frequently made of welded structure, thus, the investigation of the welding workability is inevitable.

• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.744-754
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• 2016

Asphalt concrete track (ACT) is a track system connecting wide sleepers and concrete panels on top of an asphalt concrete layer; such a system requires adequate resistance force against various longitudinal and lateral external loads. In this study, a series of experiments were carried out to assess the longitudinal and lateral resistance force of a wide sleeper and concrete panel type ACT. The required shear resistance force of the horizontal displacement restraint device (HDRD) was evaluated. Furthermore, a concrete block type anchor and a steel pipe type anchor were developed as HDRDs. The shear resistance force was decided based on the experimental results of horizontal shear tests for each anchor system. In addition, proper numbers and arrangement design guidelines for the HDRDs were suggested considering the shear resisting capacity and economics for HDRDs applied to ACT.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.1-6
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• 1999

Nearshore and offshore pipelines are often applied to carry oil, gas, water and combined products. The thermal and pressure gradients of the fluid inside pipeline cause pipeline expansion. This expansion produces stress to connecting structures with pipeline. Should this stress exceeds the yield strength of connecting components or the allowable displacement of the system, a damage can occur. As most pipelines contain hazardous and toxic fluids, the damage usually leads to fatal accidents involving great economic loss as well. Even subsea pipelines can be easily applied to transport liquid type fluid without time and space constraint, they should be designed and maintained carefully to be functional safely during design lifetime. In this paper, various theories estimating pipeline thermal expansion are investigated and the effects of pipe components to expansion are studied.