• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.1
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• pp.1-8
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• 1999

During the last 10 years, the various type of high speed craft have been greatly developed, and since around of 1990 the large size of high speed passenger and/or cargo vessels are also introduced and took into the service in the various routes over the world. In a marine traffic way some bridge need to build across a rivers, cannals or a waterways. This one will be an obstruction and potential risk of collision in the way of high speed craft. Accordingly some of collision accident have been reported, which were caused by a lost control, wind and hydrodynamic forces, fog or human errors. In this paper a high speed craft having 40 m length is assumed to be collided with a circular type of bridge piers at right angle. The mode of deformation, penetration depth of collapse, impact forces, reduction of speed, loss of kinetic energy, and influence of scantlings, etc. have been calculated in each speed with a time variation to find a maximum values within a limit, and are graphically presented.

• Journal of Navigation and Port Research
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• v.29 no.2
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• pp.119-126
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• 2005

Ferry Golden Jindo collided with Ferry Princess near the No.7 light buoy of Incheon Port No.1 Passage in restricted visibility due to dense fog. The result was that Ferry Golden Jindo got a hole at the starboard midship section shell plating and Ferry Princess sustained damages at the starboard bow and 25 persons injured The aim of this paper is to investigate this collision accident, to clarify its causes, and to prevent such accident from occurring again In short, this collision resulted from Princess' high speed in restricted visibility, Golden Jindo's carelessness of watchkeeping, lack of proper safety training of crew, lack of instruction of supervisor, carelessness af PTMS Center and indifference of Korea Shipping Association, etc.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.71-78
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• 2003

In this study, the impact analysis for the steel fender system that designed for protection of collision between vessel and bridge was peformed. The size of objective collision vessel assumed as 3000 dead weight tonnage(DWT). The impact forces and the impact energies were estimated by formulas of several design codes, and the steel fender system was designed based on the estimated forces and energy. The bow of objective vessel was modeled as rigid body, and bridge substructure was modeled as fixed support. Since, the impact analysis have the dynamic nonlinear features, such as, material nonlinear, large deformation and contact, explicit structural analysis program was used. The analysis results presented that the impact forces formulas in codes have the sufficient conservativeness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.323-330
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• 2008

The ship collision analysis of steel pile group as protection system of bridge in navigable waterways was performed to analyze the structural characteristics of protective structure during ship collision. The analysis encompassed finite element modeling of ship and pile, modeling of material non-linearity, hard impact analysis, displacement-based analysis and soft impact analysis for collision scenarios. Through the analysis of hard impact with a rigid wall, impact load for each collision type of ship bow was estimated. In the displacement-based analysis the estimate of energy which protection system can absorb within its maximum horizontal clearance so as to secure bridge pier from vessel contact during collision was performed. Soft impact analysis for various collision scenarios was conducted and the collision behaviors of vessel and pile-supported protection system were reviewed for the design of protection system. The understanding of the energy dissipation mechanism of pile supported structure and colliding vessel would give us the optimized design of protective structure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.6
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• pp.691-697
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• 2011

In this study, the vessel collision protective structure and the vessel were modeled numerically and the quasi-static collision analysis was performed to evaluate the maximum protection capacity. In the modeling process of protective structure, the nonlinear behaviors of structure and the supporting conditions of ground including pull-out action were considered. In that of collision vessel, the bow of vessel was modeled precisely, because of the nonlinear behaviors were concentrated on it. For the efficient analysis, the mass scaling scheme was applied, also. To evaluate the differences and efficiency, the dynamic analyses were performed for the same model, additionally. Based on the obtained energy dissipation curves of the structure and the vessel, the moment that the collision force affected to the bridge substructures was determined and the maximum allowable collision velocity was evaluated. Because of the energy dissipation bound can be recognized clearly, this scheme can be used efficient in engineering work.

• Journal of Ocean Engineering and Technology
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• v.22 no.2
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• pp.85-90
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• 2008

Ships in bad weather conditions are likely to be subjected to accidental loads, such as high bending moment, collision, and grounding. Once she has damage to her hull, her ultimate strength will be reduced. This paper discusses an investigation of the effect of collision damage on the ultimate strength of a ship structure by performing a series of collapse tests. For the experiment, five box-girder models with stiffeners were prepared with a cross section of $720mm\;{\times}\;720mm$ and a length of 900mm. Of the five, one had no damage and four had an ellipse shaped damage area that represented the shape of the bulbous bow of a colliding ship. The amount of damage size was different between models. Among the damaged models, the damage in three of them was made by cutting the plate and stiffener, and in one by pressing to represent collision damage. Experiments were carried out under a pure bending load and the applied load and displacements were recorded. The ultimate strength was reduced as the damage size increased, as expected. The one with the largest amount of damage had damage to 30% of the depth, and its ultimate strength was reduced by 19% compared to the undamaged one. The pressed one has higher ultimate strength than those that were cut. This might be due to the fact that the plate around the pressed damage area contributes to the ultimate strength, whereas the cut one has no plate to contribute.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.313-319
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• 2019

As vessels become larger and competition between ports intensifies, there has been an increase in the number of cases where vessels that exceed the available berths are berthed at the pier. Therefore, there has been an increase in the number of cases in which the bow or stern of a ship is projected and moored. The risk of overhanging berthing is that mooring safety can be compromised because it is not possible to connect the bow and stern mooring line to the ship properly. In addition, collision accidents may occur between moving vessels if the view of a vessel moving in the port is obstructed. Therefore, in this study, the simulation of mooring safety was performed according to the overhanging range in Piers No. 6 and 7 in Ulsan's main port to propose the overhanging limit and operational standards according to each ship. As a result of the assessment, 30,000 DWT bulkers are able to overhang up to 0.75B, and 50,000 DWT bulkers can overhang up to 0.50B. The results of this study are expected to be used as basic data for setting the allowable overhang limit, as well as clear usage criteria for safe unloading operations.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.3
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• pp.223-228
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• 2009

By the typhoon "MAEMI" in 2003, a lot of marine accidents such as stranding, collision etc. occurred to the vessels at anchor in "JINHAE MAN" which was considered one of the most safe sheltering anchorage in Korea. These accidents resulted from the dragging of anchor by the strong winds. It needs to compare the external forces with the holding powers of anchors to estimate if the anchor will be dragged or not. However, the calculation of the force by the wind on the ship, in particular, on the wind pressure area which changes by the swinging of her bow is not yet set on a thesis. Therefore, this paper verified that how many times the front wind pressure area should be applied to calculate the force by the wind on the ship at anchor by comparing and analyzing the numerical calculation with, the actual ship's data which was really dragged by the strong wind.

• Journal of the Korean earth science society
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• v.39 no.3
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• pp.241-249
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• 2018

As the international trade increases, vessel traffics around the Korean Peninsula are also increasing. Maritime accidents hence take place more frequently in the southern coast of Korea where many big and small ports are located. Accidents involving ship collision and sinking result in a substantial human and material damage as well as the marine environmental pollution. Therefore, it is necessary to locate the ships quickly when such accidents occur. In this study, we suggest a new ship detection index by comparing and analyzing the reflectivity of each channel of the Korea MultiPurpose SATellite-2 (KOMPSAT-2) images of the area around the Gwangyang Bay. A threshold value of 0.1 is set based on a histogram analysis, and all vessels are detected when compared with RGB composite images. After selecting a relatively large ship as a representative sample, the distribution of spatial reflectivity around the ship is studied. Uniform shadows are detected on the northwest side of the vessel. This indicates that the sun is in the southeast, the azimuth of the actual satellite image is $144.80^{\circ}$, and the azimuth angle of the sun can be estimated using the shadow position. The reflectivity of the shadows is 0.005 lower than the surrounding sea and ship. The shadow height varies with the position of the bow and the stern, perhaps due to the relative heights of the ship deck and the structure. The results of this study can help search technology for missing vessels using optical satellite images in the event of a marine accident around the Korean Peninsula.