• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.863-870
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• 2023

Ship capsize accidents are common in coastal waters, particularly involving small fishing boats. To prevent there overturing accidents in small fishing boats, their stabilities must be assessed at the initial design step. However, the available information during the initial design step is limited, posing challenges in performing a reliable stability evaluation. Therefore, this study presents a plan to estimate the transverse metacenter (GM) of small fishing boats using parameters such as KM, KG, and TRIM that can be determined at the initial design step. Stability was evaluated by comparing GM with the minimum transverse metacenter (GMmin) specified in the standard safety evaluation criteria for fishing boats. To calculate the required trim value for hydrostatic characteristics using K-SHIP, a stability assessment program provided by the Korea Maritime Safety and Transportation Corporation, the initial trim state is estimated based on the ship lines using the commercial CFD program STAR-CCM+. GM is then calculated by assessing the hydrostatic characteristics in relation to the boat lines using K-SHIP. Furthermore, the stability of the fully loaded state is compared by subtrcating GM from GMmin. One constructed ship is designated as the standard ship, and the stability assessment method proposed in this study is applied to evaluate stability and validate its effectiveness. Consequently, the representative line of a 4.99-ton fishing boat and nine modular lines models derived from it were evaluated, ultimately identifying a relatively superior stability.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.172-178
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• 2014

This study suggests the minimum critical external forces based on the assessment of anchoring safety to single anchor situation for representative 8 number of ships in E-group anchorage of Ulsan port. Assessment of anchoring safety is compared holding powers of anchor with external forces of wind, wave and current. Holding powers was reflected materials of seabed, equipment numbers regarding anchor and chain weight, also external forces acting on a hull was calculated considering projected wind area and wetted surface area to the full and ballast conditions respectively. The results of anchoring safety assessments to single anchor showed that the minimum criteria of dragging anchor is a little different from ship's type, size and loading conditions. Bulk carrier can be dragged over the 15m/s of winds and Tanker can be dragged over the 13m/s of winds in case of less than 2knots of currents speed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.209-216
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• 2004

In A bridge which connects Mokpo North Harbor and Com Island is going to be constructed until 2009. For the bridges being built in the navigable water area, it is indispensible to carry out vessel traffic safety assessment from the viewpoint of shiphandlers, however, there exist no specific guidelines for the necessary conditions whim the bridge designers can rely on. In this paper, traffic safety assessment procedures for the layout of the bridge is briefly introduced, and the conditions whim should be taken into account at the initial design stage of the bridge is surveyed. For the safety assessment of the bridge design, ship navigation simulations, such as RTS(real time simulation} and FTS(fast time simulation), are carried out, the results of which are statistically analysed to estimate the probability of collision between the ship and the pier of the bridge.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.735-743
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• 2004

A bridge which connects Mokpo North Harbor and Goha Island is going to be constructed until 2009. For the bridges being built in the navigable water area, it is indispensible to carry out vessel traffic safety assessment from the viewpoint of shiphandlers, however, there exist no specific guidelines for the necessary conditions which the bridge designers can rely on. In this paper, traffic safety assessment procedures for the layout of the bridge are briefly introduced, and the conditions which should be taken into account at the initial design stage of the bridge are surveyed For the safety assessment of the bridge design, ship navigation simulations, such as RTS( real time simulation) and FTS(fast time simulation), are carried out, the results of which are statistically analysed to estimate the probability of collision between the ship and the pier of the bridge.

• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.247-252
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• 2003

This paper is mainly concerned with the assessment of safe navigation between ships moving each other in restricted waterways. The numerical simulation of manoeuvring motion was conducted parametrically to propose an appropriate safe speed and distance, which is required to avoid sea accident under the different conditions, such as ship-velocity ratios, ship-length ratios, separation and stagger between ships. As for the calculation parameters, the ratios of velocity difference between two ships were considered as 0.6, 1.2, 1.5 and the ones of ship-length difference were regarded were regarded as 0.5, 1.0, 1.18. From the inspection of this investigation, it indicates the following result. Firstly, the separation between ships is more needed for the small vessel, compared to the large vessel. Secondly, the lateral distance between ships is necessarily required for the velocity ration of 1.2, compared to the cases of 0.6 and 1.5. The manoeuvring characteristics based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in confined water.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.71-75
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• 2005

From the viewpoint of navigation safety, it would be best if it's possible to build a bridge whose main span is wide enough, however, sometimes it may not be possible due to geographical or economic reason To construct the bridge on the shipping route, consideration factors for marine traffic safety must be investigated and examined from the viewpoint of marine traffic engineering. This study aims to secure marine traffic safety and maintain smoothly traffic flow through assessment qf these factors. As the first step, examination factors such as traffic volume, ship size and bridge width were assessed quantitatively using marine traffic flow simulation technique.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.21-32
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• 2002

In accordance with the development plans of Ulsan harbor, Ulsan new harbor will be contructed considering supporting Ulsan harbor as a safe berthing and departure at single buoy mooring(SBM). In this study, we used a full-mission ship handling simulator adopting 300,000 DWT VLCC manoeuvered at the planned Ulsan SBM. Five masters who have had a long experience of ship maneuvering were called to carry out the simulations, of which each scenario were tried one, completed total of 68 times. The marine traffic safety was assessed in terms of 1) the closest point of approach(CPA) to other SBM and breakwater in the vicinity and the probability of crossing the restricted area of the closest SBM and fairway limit, 2) subjective evaluation such as the mental burden and the maneuvering difficulty of shiphanders, and 3) the opinions of shiphandlers. From the result of this simulation, we have a conclusion as follows; First, because crude oil berthing angle is so small by current S-OiL Co. crude oil buoy by SK Co. No 3 crude oil buoy different view SK Co. No 3 crude oil buoy and interference of current KNOC crude oil buoy, Berthing is impossible, and Emergency departing is very dangerous too operation impossible. Second it is desirable that SK Co. No 2 and No 3 Single buoy Mooring that do different view controls position so that to be not put in straight line each other. Third, SK Co. No 1 and 2 single buoy mooring that do different view to Onsanhang berthing and departing is seized by single buoy mooring by external force ship that set sail does faith control need.

• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.151-158
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• 2012

The objective of this paper is to propose a method of how to perform risk assessment in the early stage of defense research and development for the acquisition of weapon systems. An advanced method for risk assessment and its associated objective functions are developed first based on the concept of systems engineering. The developed method is then applied to carry out the analysis of alternatives in the trade-off environments. As a case study, the multi-purpose training ship is considered, where it is performed using the notions of technology readiness levels, degrees of difficulty, and technology need values to facilitate design space visualization and decision maker interaction. It is noted that decision makers can benefit from our approach as an improved risk assessment method in the context of multi-criteria decision making.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.254-261
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• 2004

Until now, there are different kinds of design and evaluation method criteria for ship hulls and ship strength based on allowable stress design using past experiences. But for many sinking accidents of large ships in operation, it has also a doubt about allowable stress design. It is recognized that structural plastic collapse caused by large external force is a main cause of that accidents. Therefore, there is the need for new design criteria based on ultimate limit state with a consideration about progressive collapse behavior as a safety assessment of ship hulls. Also many aluminum alloy ships is built for the purposes of lightweight of ship hulls, with that, a developing of criteria based on ultimate limit state should be made. In this study, the ultimate strength characteristics of aluminum ship hull are investigated by the ALPS/USAS program using already developed design formula for aluminum plate and stiffened panel.

• Journal of Navigation and Port Research
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• v.34 no.9
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• pp.699-704
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• 2010

Recently, the navigation risk is increasing significantly with growing of vessels' volume and propelling marine facilities, water bridges and port development etc. As a result, Ministry of Land, Transport and Maritime Affairs enacted a new law called MSA(Maritime Safety Audit) as a comprehensive maritime traffic safety management scheme in order to ensure safety improvements from the early planning stage to post managing of the development which affect the maritime traffic environment. MSA as a tool for improving maritime traffic safety is a formal safety diagnosis assessment in the existing or future ship's fairway by an independent audit institute. It examines the potential hazards of maritime traffic safety about the port development, if necessary, and is to ensure the implementation of appropriate safety measures. The primary purpose of MSA is to identify potential risk elements affecting safe navigation. This paper is aimed to introduce the backgrounds, the necessity and efficiency of MSA and also to describe some technical standards and diagnostic procedures.