• Journal of Korea Ship Safrty Technology Authority
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• s.23
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• pp.2-13
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• 2007

With the effectuation of the amendment of MARPOL 73/78 on 5 April 2005, enforcement regulations of Marine Pollution Prevention Act were revised in domestic on 12 March 2005 that double hull structure was required to the small single bottom oil tankers under DWT(deadweight tonnage) 500 ton for the protection of the marine pollution casualties. The objective of this study is to develop the double bottom structure of small oil tanker under DWT 500 ton with superior crashworthiness and to establish its suitable standard to double bottom structure. The promoting strategy of this R&D is classified into the crashworthy structural analysis of small oil tankers using LS/DYNA3D code and the examination of their damage stabilities according to tonnage. It could be thought that the desirable inner bottom height should be above the B/7.5 and its minimum height 0.65m for the domestic small oil tanker under DWT 500ton.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.05a
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• pp.117-122
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• 1995

원자력의 이용 분야 확대를 위하여 선박용 소형 동력로를 설계하였다. 본 연구에서는 다음의 제한 조건 및 설계 조건을 설정하여 핵적 개념 설계를 수행하였다. 노심의 부피는 국내 제작가능한 VLCC기종 유조선 기관실내에 배치 가능하도록 제한하였고, 선박의 정기 점검 기간에 맞춘 핵연료 재장전 주기 길이, 무붕산 노심 운전, 상용 가압경수로 보다 낮은 선출력과 출력 밀도, MUTSU호와 같은 1차 계통 열수력 조건, 등의 설계 조건을 설정하였다. 울진 3＆4의 핵연료 집합체의 길이만을 짧게 하여 사용하는 것에 대한 타당성 모색을 핵적 개념 설계 목표로 삼았다. 핵연료 집합체의 설계 및 반응단면적 생산은 CASMO-3 코트를, 노심 전체의 분석은 3차원 노달 코드인 KINS-3코트를 사용하였다. 개념 설계 결과, 노심 주기길이 690일을 달성할 수 있는 핵연료 집합체의 농축도와 갯수는 1.88%의 17개, 3.3%의 20개로 결정하였고, F$_{Q}$는 2.833이였고, 운전 상태에서의 감속재 온도 개수는 -24.8 pcm/$^{\circ}C$로 나타나서 한국형 원자로용 핵연료 집합체를 그대로 선박용 원자로에 사용 가능함을 볼 수 있었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.4
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• pp.204-209
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• 2008

Marine accidents show various causes and effects in Korea where 3 sides of the country are surrounded by the ocean. Every year, 600 to 700 marine accidents occur mostly by small fishing boats. There are repeated accidents which involve crashes of coastal ships with fishing boats, which produce casualties and massive environmental hazard and the need for underwater search for shipwrecks. From the beginning of 21st century, the decrease of large ships with large number of crews led to the emergence of digitalvessels and the digital data storage of the installed equipments on the vessels, marine digital forensic - the extraction and analysis of the stored digital data within digital vessels - became necessary. This article is intended to suggest marine digital forensics as a solution of collecting evidence for discovering the causes, liabilities and compensations of marine accidents.

• Journal of Fisheries and Marine Sciences Education
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• v.14 no.2
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• pp.149-160
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• 2002

I have been analyzed the marine accidents during 10years(1992~2001) based on the maritime inquire court decision, the results were as follows: 1. The rate of accident occuring were showed fishing boat(69.9%), freighter(12.3%), tanker(4.3%), tug boat(3.8%), passenger boat(2.1%) by the usage. 2. The marine accident had been showed operational fault(67.3%), mishandling of engine equipment(21.7%), meteorological condition, etc(11%) by the reason, most accidents had been occured by the operator fault and rack of experience. 3. The marine accidents had been showed damage of hull and engine(27.5%), collision(24%), foundering(11.3%), fire(3.9%), agrounding(10%), by the kind of accidents. 4. The accidents had been occured (74.6%) at the coastal sea, harbour and (25.4%) at the open sea by the sectors. The accidents of the vessel less than 500ton were much increased (54.3%) also, The accidents were much occured at the time between 0400~0800 hours by the time.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.4
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• pp.21-31
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• 2001

When an oil-spilling accident occurs at sea, it is of the primary importance to predict the amount of oil leakage for the swift response and decision-making. The simplest method of oil-leakage estimation is based on the hydrostatic pressure balance between oil inside the tank and seawater outside of leakage hole, that is the so-called Torricelli equilibrium relation. However, there exists discrepancy between the reality and the Torricelli relation, since the latter is obtained from the quasi-steady treatment of Bernoulli equation ignoring viscous friction. A preliminary experiment has been performed to find out the oil-leaking speed and shape. Soy-bean oil inside the inner tank was ejected into water of the outer tank through four different leakage holes to record the amount of oil leakage. Furthermore, a CFD (Computational Fluid Dynamics) method was utilized to simulate the experimental situation. The Wavier-Stokes equations were solved for two-density flow of oil and water. VOF method was employed to capture the shape of their interface. It is found that the oil-leaking speed varies due to the frictional resistance of the leakage hole passage dependent on its aspect ratio. The Torricelli factor relating the speed predicted by using the hydrostatic balance and the real leakage speed is assessed. For the present experimental setup, Torricelli factors were in the range of 35%~55% depending on the aspect ratio of leakage holes. On the other hand, CFD results predicted that Torricelli factor could be 52% regardless of the aspect ratio of the leakage holes, when the frictional resistance of leakage hole passage was neglected.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.31-38
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• 2020

The characteristics of ship traffic routes and the long term fluctuation in marine traf ic volume of the incoming and outgoing routes of the Yeosu Gwangyang Port were analyzed using vessel traffic data from the past 22 years and a real-time vessel traffic volume survey performed for 72 hours per year, for three years, between 2015 and 2017. As of 2017, the number of vessels passing through Yeosu Gwangyang Port was about 66,000 and the total tonnage of these ships was about 804,564 thousand tons, which is a 400 % increase from the 189,906 thousand tons shipped in 1996. Specifically, the dangerous cargo volume was 140,000 thousand tons, which is a 250 % increase compared to 1996. According to the real-time vessel traffic volume survey, the average daily number of vessels was 357, and traf ic route utilization rates were 28.1 % in the Nakpo sea area, 43.8 % in the specified sea area, and the coastal area traf ic route, Dolsan coastal area, and Kumhodo sea area showed the same rate of 6.8 %. Many routes meet in the Nakpo sea area and, parallel and cross passing were frequent. Many small work vessels entered the specific sea area from the neighboring coastal area traffic route and frequently intersected the path of larger vessels. The anchorage waiting rate for cargo ships was about 24 %, and the nightly passing rate for dangerous cargo ships such as chemical vessels and tankers was about 20 %. Although the vessel traffic volume of Yeosu Gwangyang Port increases every year, the vessel traffic routes remain the same. Therefore, the risk of accidents is constantly increasing. The route conditions must be improved by dredging and expanding the available routes to reduce the high risk of ship accidents due to overlapping routes, by removing reefs, and by reinforcing navigational aids. In addition, the entry and exit time for dangerous cargo ships at high-risk ports must be strictly regulated. Advancements in the VTS system can help to actively manage the traffic of small vessels using the coastal area traffic route.