• Journal of Ship and Ocean Technology
• /
• 제10권1호
• /
• pp.27-37
• /
• 2006

Current loads acting on offshore vessels are important for predicting the hydrodynamic and structural responses of the vessels. It is also true for analyzing the behavior of moored systems under the action of ocean current. Unfortunately there are few standardized current load coefficients for offshore vessels and it is extremely difficult to be applied to arbitrary hull shapes, if any. Therefore current load coefficients for three hull shapes are calculated in this study using a CFD code, which is well known in the shipbuilding industry. In order to validate the present approach, a typical VLCC is taken as numerical example and resulting current coefficients are compared with experiment together with the OCIMF data. The comparison shows a good agreement in the qualitative sense. Two additional models considered herein are a shuttle tanker and a FPSO under deepwater condition $(WD/T{\geq}6)$. The present numerical approach may be utilized for practical design of offshore vessels.

• 해양환경안전학회지
• /
• 제23권3호
• /
• pp.231-241
• /
• 2017

The purpose of this study was to analyze traffic safety assessments for fishing vessels near the southwest offshore wind farm. This study applied a collision model for safety assessment. It also involved a spatiotemporal analysis of vessels engaged in fishing to identify fishing hotspots around the offshore wind farm. This study used data from fishing vessel location transmission devices gathered over 1 year in 2014. As a result, in September, when the average number of vessels engaged in fishing is high, 62 ships were operating in fishing section 184-6 and 55 ships in section 184-6. In addition, in fishing sections 184-8 and 192-2, where an offshore wind farm was located, there were 55 and 38 ships operating, respectively. As the recovery period for a seaway near wind farm turbines is 55 years, it was determined that safety measures are required in order to reduce collision frequency while allowing fishing vessels to navigate through offshore wind farms. Meanwhile, the return period of Seaway B between the groups of generators considered was 184 years. A safety zone for offshore wind farms should be installed covering a distance of at least 0.3 NM from the boundary of turbines. Then, the collision return period was derived to be close to 100 years. Through this traffic safety assessment, it has been concluded that such measures would help prevent marine accidents.

• 수산해양기술연구
• /
• 제59권2호
• /
• pp.172-180
• /
• 2023

Although it is highly dependent on the production of coastal and offshore fishing, the Fishing Vessels Safety Fisheries Act was enacted in 2019 due to the continuous increase in marine accidents of coastal and offshore fishing vessels. However, the law is too focused on fishing and navigation in certain waters and does not contain accident-preventive content. Ministry of Oceans and Fisheries proposes a plan to revise the Fishing Boat Safety Fishing Act through legal comparison with Japan's Seafarers' Labor Sanitation Rules. It also proposes an amendment that includes the content of the Seafarers Act on post-accident action obligations. Under the Fishing Vessels Safety Fishing Act, the safety fishing education is implemented for specific people and adopts a method of delivery education after completing the education. The reason for this is that the educational requirements are not sufficient compared to the number of education personnel. Moreover, four hours of education are conducted once a year, which is not suitable for insufficient educational conditions. For efficient safety fishing education, improvement measures are proposed compared to education in the United States and the United Kingdom.

• 수산해양교육연구
• /
• 제27권3호
• /
• pp.821-832
• /
• 2015

The aims of this study are to estimate the optimal vessel reduction scales and these direct economic effects of coastal and offshore fisheries in the Republic of Korea. To estimate respectively optimal fishing efforts of individual fishery by species in coastal and offshore fisheries, we adopted appropriate fishing power of each species published by National Fisheries Research and Development Institute and also considered biological and socio-economic factors such as the bycatch rate, the profit rate, the efficiency of resource use, the average age of fishing vessel, the intention of vessel reduction, and the annual changes in vessels by other factors. The direct economic effects of the optimal vessel reduction in coastal and offshore fisheries based on maximum sustainable yield and 2/3 maximum sustainable yield was calculated by a cost-benefit analysis. This study showed that optimal reduction numbers of vessels engaged in coastal and offshore fisheries were 4,431 and 374 vessels and the direct economic effects in coastal and offshore fisheries were about 371.7 and 569.4 billion won and these NPV and BCR were 111.7 billion won and 1.65 and 342.6 billion won and 4.97 respectively.

• 수산해양기술연구
• /
• 제54권1호
• /
• pp.65-72
• /
• 2018

This study analyzed the condition of marine accident and disaster rate of crew of Korean fishing vessels by vessel type, and checked the Australian safety management system and relevant regulation in Korea to suggest measures to build coastal/offshore fishing vessel safety management system in Korean coastal/offshore fishery. As a result, the power and production amount of Korean coastal/offshore fishing vessel is consistently decreasing while marine accident is increasing. Disaster rate of crew was higher than land industry, especially, the disaster rate of coastal/offshore fishing vessel was very high (100.0‰). Australia applies safety management system differed by vessel type and operation waters which fully considers the characteristics of pertinent vessel. The average accident rate of fishing vessels with gross tonnage over 20 tons among the Korean coastal/offshore fishing vessel was 13.6%, which was significantly higher than fishing vessels with gross tonnage below 20 tons (1.4%). Such result indicates it is urgent to implement safety management system to fishing vessel with gross tonnage over 20 tons and introduce fishing vessel safety supervisor. Establishing safety management system of coastal/offshore fishing vessel will contribute to consistent industrial development by achieving the general goal of reducing marine accident and spreading safety culture.

• 수산해양기술연구
• /
• 제50권1호
• /
• pp.21-29
• /
• 2014

The dynamic information of radar and automatic identification system (AIS) for targets obtained from the traffic vessels operating in the north outer harbor and surrounding waters of Busan port, Korea. The target information was analyzed to investigate the potential collision risk resulting from the invalid true heading (HDT) information of AIS and the integration ambiguity in the graphic presentation of both tracked data sets for two systems. An integrated display system (IDS) for supporting the navigator of offshore fishing vessels was also developed to find possible maneuvering solutions for collision avoidance by comparing radar data with AIS data in real-time at sea. Consequently, the multiple functions of IDS can provide additional information that is potentially valuable for taking action to avoid the collision in offshore fishing vessels. However, the integration criteria of radar and AIS targets in the IDS must be carefully established to eliminate the fusion ambiguity in the graphic presentation of both AIS and radar symbols such as the one or two physical targets which are very close to each other.

• 한국해양공학회지
• /
• 제38권3호
• /
• pp.124-136
• /
• 2024

As the number of offshore wind-power installations increases, collision accidents with vessels occur more frequently. This study investigates the risk of collision damage with operating vessels that may occur during the operation of an offshore wind turbine. The floater used in the collision study is a 15 MW UMaine VolturnUS-S (semi-submersible type), and the colliding ships are selected as multi-purpose vessels, service operation vessels, or anchor-handling tug ships based on their operational purpose. Collision analysis is performed using ABAQUS and substantiation is performed via a drop impact test. The collision analyses are conducted by varying the ship velocity, displacement, collision angle, and ship shape. By applying this numerical model, the extent of damage and deformation of the collision area is confirmed. The analysis results show that a vessel with a bulbous bow can cause flooding, depending on the collision conditions. For damage caused by collision, various collision angles must be considered based on the internal stiffener arrangement. Additionally, the floater can be flooded with relatively small collision energy when the colliding vessel has a bulbous bow.

• Ocean and Polar Research
• /
• 제36권4호
• /
• pp.343-351
• /
• 2014

The purpose of this study is to estimate the economic value and productivity achieved through a reduction in fishing vessels engaged in coastal and offshore fisheries. We found that the value of increasing catch by types in offshore and coastal fisheries was about 17,338 billion won. To examine the economic value, a cost-benefit analysis was applied. This is based on the total cost of vessel reduction (4,576 billion won) assumed to be invested equally each year for five years. BCR and NPV with a discount rate (5.5%) were used to compare the profit of fishery activities in offshore and coastal areas. The model results showed that the NPV and BCR in offshore and coastal fisheries was 5,522 billion won and 2.340 respectively.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제9권1호
• /
• pp.45-54
• /
• 2017

The purpose of this study is to evaluate various means of wind power turbines installation in the Korean west-south wind farm (Test bed 100 MW, Demonstrate site 400 MW). We presented the marine environment of the southwest offshore wind farm in order to decide the appropriate installation vessel to be used in this site. The various vessels would be WTIV (Wind turbine installation vessel), jack-up barge, or floating crane ${\cdots}$ etc. We analyzed the installation cost of offshore wind turbine and the transportation duration for each vessel. The analysis results showed the most suitable installation means for offshore wind turbine in the Korean west-south wind farm.

• 해양환경안전학회지
• /
• 제24권7호
• /
• pp.841-847
• /
• 2018

세계 에너지 소비와 에너지 수요가 급격히 증가함에 따라 환경문제와 지속가능성에 대한 관심이 요즘 더욱 중요해지고 있다. 신재생에너지 중 해상풍력발전과 같은 깨끗하고 재생가능한 에너지자원은 대체에너지 자원으로 주목받고 있다. 유지보수 및 운영상의 관점에서 해상풍력발전은 일반적으로 연근해해역에 설치될 계획이지만 해상풍력발전단지의 개발은 계획된 풍력단지를 따라 기존의 해상교통으로부터 다양한 해상교통 간섭에 직면해 있는 실정이다. 해상풍력발전단지 인근해역 및 단지 내에서 해상교통을 안전하고 효과적으로 통제하기 위해 선박이 해상풍력단지 내에서 통항할 수 있도록 표준 기준을 제안한다. 따라서, 본 연구의 목적은 국외 해상풍력발전단지의 현지 규정을 조사하여 해상풍력발전단지에 대한 선박통항 허용 및 안전구역 기준을 수립 하는데 있다. 풍력단지의 내측 안전구역은 풍력터빈 날개 회전직경의 150 %를 적용한 거리와 외측안전구역으로는 외곽에 위치한 풍력터빈으로부터 200 m의 범위의 거리를 제시하였으며, 또한 풍력단지 내 선박통항 허용기준은 풍력터빈 날개의 높이와 조위를 평가하여 향후 서남해 해상풍력발전단지의 실증단지 해역에서 Air draft 14.47 m가 선체 접촉을 피할 수 있는 최소 마진을 가진 기준을 제시하였다. 향후 연구과제로서, 단일 해상풍력단지 내의 선박 통항 기준과 더불어 인접한 해상풍력단지 간의 선박통항 기준마련을 위한 후속연구가 필요하다.