• Title/Summary/Keyword: fishing vessel

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The Stability Analysis of the 8 Ton Class Fishing Vessel in Seaway (파랑중 8톤급 어선의 복원력 분석)

  • 이희상
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.147-155
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    • 1999
  • In this study, the stability analysis of a fishing vessel in a seaway was done. The stability analysis is an important item in the ship design, and so the ship registers of each nation constrain the ships to be followed the stability criterion. Stability variation, exciting forces due to wave and wind, and the broaching phenomena cause the capsizing of a ship. In this study, the stability analysis to study of the capsizing of a fishing vessel was performed. The relation between the speed of the ship and the wave length, that makes the encountering frequency vanish, was obtained. It was found that the encountering frequency tend to be zero when the wave whose length and direction are similar to those of ship. In this case, the possibility of dangerous situation becomes high. The calculated restoring arm becomes small when the ship is located near the wave crest. In general, the selected small fishing vessel is better than the large ship with respect to the stability, however the wave height becomes relatively high because of her small length Kim(l994) calculated the stability variation of the large cargo ship, the results of which showed the changes in stability great. But in the selected small fishing vessel in this study, the changes was small in comparison with the larger ship. This reason seems to be the shape of her midship section. In large cargo ships, the block coefficient is large, but that of the fishing vessel is relatively small and the small fishing vessel has chine, therefore the center of buoyancy moves much when the ship is inclined. It is desirable that the dynamic stability analysis for a fishing vessel, whose speed and direction are similar to those of waves, shall be done in the near future.

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The improvement of the shellfish dredge vessel in Jeonnam province (전남 지역의 패류 형망어선의 개량)

  • PARK, Sang-Jun;JANG, Choong-Sik;AN, Young-Su;JIN, Song-Han;CHO, Youn-Hyoung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.162-171
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    • 2019
  • This study is aimed to develop an improved shellfish dredge vessel considering the increase of the fishing safety and welfare of fishermen in Jeonnam province. We visited five fishing village societies in Korea, and conducted field surveys and survey questions to investigate the current status. In order to solve the problems presented by the investigation, a general arrangement of the improvement vessel was written and adopted after meeting between the fishermen and research team, and calculated the initial stability in five loading conditions by using the Napa program. As a result of field surveys and survey questions, the existing vessel have buoyant materials under the bow and the warp pass through the wheel-house. In addition, most fishing equipment and nets are concentrated on a narrow stern, making it difficult to work efficiently. According to the survey, fishermen also responded that operation of casting and hauling is very inconvenient. The fishing equipment of the improvement vessel was rearranged, the size of the wheel-house and the crew room was increased, and we secured a basic welfare space. As a result of the initial stability test, the stability criteria of the fishing vessel were satisfied in all loading condition.

Allocation of the skipper's attention depending on the longline fishing process of the coastal composite fishing vessel (연안복합어선의 연승조업과정에 따른 선장의 주의 배분)

  • KIM, Min-Son;HWANG, Bo-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.2
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    • pp.175-184
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    • 2022
  • This study analyzed the allocation of the skipper's attention during fishing operation in the wheelhouse of a Korean coastal composite fishing vessel by using video observation. To summarize the results, the ratio of lookout, radar and GPS monitoring, which is essential for prevention of collision at sea, was significantly lower than that of other fishing operation due to the attention concentration on the work place during hauling line. In order to reduce exposure to risk of collisions due to concentration of attention to certain tasks such as line hauling, it is necessary to develop an alert system that can notify the approach of other ships or obstruction throughout the ship using information from radar or the automatic identification system. In addition, the order of attention allocation to devices and facilities obtained in this study is expected to be used as basic data for device or facility layout based on the principle of usage frequency in designing wheelhouse for coastal composite fishing vessels in the future.

A Study on the Initial Stability Evaluation of 4.99-Tons-Class Standard Fishing Vessels (4.99톤급 표준어선형 어선의 초기 복원성 평가에 관한 연구)

  • Hwewoo Kim;Sanghyun Kim;Sunwoo Lee;Hyeongseok Yoon;Hyogeun Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.2
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    • pp.176-183
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    • 2024
  • Assessing the stability of small fishing vessels is important to prevent capsize accidents in coastal waters that primarily occur on small fishing vessels. However, the regulations regarding stability assessment for small vessels under 24 m are inadequate according to the domestic Fisheries Act. Based on safety standards issued by the Ministry of Oceans and Fisheries in 2022 to enhance safety and welfare, vessels adhering to the enhanced safety standards for standard ship types are required to establish stability regardless of their length. This study aims to utilize these aforementioned standards to assess the stability of vessels under 24 m, investigating the suitability of applying these criteria to these vessels and examining the impact on various small vessels with different superstructures. Initially, a 4.99-ton fishing vessel designed according to the standard ship type was selected as the subject vessel. Compliance with the standards was evaluated based on the initial stability of the vessel using the transverse metacentric height (GM) and transverse restoring moment arm at the limit angle (GZα). Additionally, six types of small vessels with identical hull forms and specifications to the subject vessel were further examined using prevalent superstructure designs in small fishing vessels. The stability of the subject small vessel was also assessed. A study of a 4.99-ton standard fishing vessel confirmed that the safety standards for standard fishing vessels with enhanced safety welfare were applicable to small fishing vessels under 4.99-ton class and that the stability of small fishing vessels with superstructure modifications was not significantly changed.

A method of calculating the number of fishing operation days for fishery compensation using fishing vessel trajectory data (어선 항적데이터를 활용한 어업손실보상을 위한 조업일수 산출 방법)

  • KIM, Kwang-Il;KIM, Keun-Huyng;YOO, Sang-Lok;KIM, Seok-Jong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.4
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    • pp.334-341
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    • 2021
  • The fishery compensation by marine spatial planning such as routeing of ships and offshore wind farms is required objective data on whether fishing vessels are engaged in a target area. There has still been no research that calculated the number of fishing operation days scientifically. This study proposes a novel method for calculating the number of fishing operation days using the fishing trajectory data when investigating fishery compensation in marine spatial planning areas. It was calculated by multiplying the average reporting interval of trajectory data, the number of collected data, the status weighting factor, and the weighting factor for fishery compensation according to the location of each fishing vessel. In particular, the number of fishing operation days for the compensation of driftnet fishery was considered the daily average number of large vessels from the port and the fishery loss hours for avoiding collisions with them. The target area for applying the proposed method is the routeing area of ships of Jeju outer port. The yearly average fishing operation days were calculated from three years of data from 2017 to 2019. As a result of the study, the yearly average fishing operation days for the compensation of each fishing village fraternity varied from 0.0 to 39.0 days. The proposed method can be used for fishery compensation as an objective indicator in various marine spatial planning areas.

A Study on VDR System for a Small Fishing Vessel (소형어선을 위한 VDR 시스템에 관한 연구)

  • Yoo, Nam-Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.11
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    • pp.1025-1030
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    • 2016
  • The big problem of accidents at sea is negligent watch, it causes collision, fender bender, stranding, rollover, and sinking of fishing vessel. Most accidents happens without an eyewitness, it is difficult to identify the cause of the accident. VDR(: Voyage Data Recorder) is needed to identify a cause of the accident, the VDR is not usually used for fishing vessel because of high cost. Thus, this paper designs and develops a VDR system for fishing vessel. If the system is used, cause of a sea accident can be quickly identified. Also, a VDR system can be used for appropriate measures to fix a cause of the accident. Finally, it also can be helpful to prevent maritime accidents.

Safety countermeasures for the marine casualties of fishing vessels in Korea (우리나라의 어선 해양사고에 대한 안전대책)

  • Kang, Il-Kwon;Kim, Hyung-Seok;Shin, Hyeong-Il;Lee, Yoo-Won;Kim, Jeong-Chang;Jo, Hyo-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.43 no.2
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    • pp.149-159
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    • 2007
  • Marine casualties of fishing vessels were analyzed to reduce the sacrifice of human life using data of the Korean Maritime Safety Tribunal from 1995 to 2004 in Korea. The occurred number of fishing vessel casualties were likely to be higher portion than non-fishing vessels, but the occurring ratio of fishing vessel casualties were marked 2.96 times lower than that of non-fishing vessel casualties. The occurring ratios of bigger fishing vessel casualties were higher than smaller ones. Most marine casualties were resulted from the human factors such as poor watchkeeping, negligent action for engine and etc. The trend of marine casualties showed that the machinery damage hold the first and collision accidents took the second, but on a point of cause of them, operating errors took first and poor handling or inspection of machinery held the second place. Because those two casualties took major portion, and very important problems for safety of fishing vessels, so we ought to try to reduce the factors before everything else. In addition, since collision, sinking and capsizing in marine casualties have led to death, missing and injury of lives, it is necessary for navigation operators to take more educations and training intended to reduce the marine casualties systematically and continuously.

Estimation of drafts and metacentric heights of small fishing vessels according to loading conditions

  • Kim, Dong Jin;Yeo, Dong Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.199-212
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    • 2020
  • A large percentage of maritime accidents in coastal seas are related to small fishing vessels. In order to investigate causes of maritime accidents, it is often necessary to carry out dynamic simulations for the estimation of trajectories and motions of vessels. Initial conditions of vessels such as main dimensions, loading conditions and hydrostatic properties are required for the accurate simulations. Small fishing vessels usually have few records of hydrostatic properties during their fishing operations. Therefore, in this study, estimation procedures for hydrostatic properties of small fishing vessels are proposed. At first, hull form characteristics of Korean small fishing vessels are investigated. Most of vessels have hard-chines and centerline skegs, they have similar hull forms. Bonjean curves of several small fishing vessels whose gross tonnages are below 10 tons are normalized with vessel breadths and depths. Representative bonjean curves are derived from normalized bonjean curves, and a representative hull plan is obtained as well. If the vessel loading conditions such as total weights and centers of gravity are given, fore and aft drafts can be calculated by using the representative bonjean curves with the constraint that weights and buoyancies are in equilibrium. Metacentric heights are also estimated by using the representative hull plan. Drafts and metacentric heights estimated by proposed iterative estimation procedures are compared with actual vessel data, estimated values are in good agreements with actual values. In addition, normalized fore and aft drafts, metacentric heights of vessels can be formulated as the linear functions of normalized total weights and centers of gravity. Empirical formulas of drafts and metacentric heights are proposed, and it is confirmed that the empirical formulas also provide reasonable results, which are similar to the results by iterative estimation procedures with representative bonjean curves and hull plan.

Change of relative fishing power index from technological development in the offshore large powered purse seine fishery (근해대형선망어업에서 어로기술개발에 따른 어획성능지수 변동)

  • SEO, Young-Il;HWANG, Kang-Seok;CHA, Hyung-Kee;OH, Taeg-Yun;JO, Hyun-Su;KIM, Byung-Yeob;RYU, Kyong-Jin;LEE, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.1
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    • pp.12-18
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    • 2017
  • Lots of fishery stocks are overexploited and the overcapacity exists in Korean fishing fleets. One of the reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore large powered purse seine fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. Fishing gear material was changed to the knotless webbing to settle faster. Fishing equipments was modernized and supply rate was also increased. Therefore the relative fishing power index in the offshore large powered purse seine fishery increased from 0.4 in 1970 to 1.0 in 1980, to 1.5 in 2000 and to 1.6 in 2010, but the rate of increase slowed down gradually. The results are expected to contribute to reasonable fishery stock management.

A Statistical Approach for the Determination of Location and Range of Fishing Grounds in the Coastal Vessel Fishery (통계학적 접근에 의한 연안어업의 조업어장 위치 및 범위결정 에 관한 연구)

  • Kang, Y.J.;Kim, K.S.;Yi, S.B.
    • The Journal of Fisheries Business Administration
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    • v.38 no.1 s.73
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    • pp.97-113
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    • 2007
  • This study attempts to suggest a new approach of the the determination of location and range of fishing ground in the coastal vessel fishery using the anaiysis of variance(ANOVA) and least significant difference test(LSD test) in statistics. The important result of the empirical study is that there is no significant difference in fisfishing ground based on between fishermen's argument and spot investigation. But there is stastitically significant difference in fisfishing ground based on between fishermen's argument and the official documents of fishing records for past three years. The results suggest us that there exists a possibility of misuse of tax free oil providied for subsidizing fisheries. But because of the range limitation of data, it is impossible for us to generalize the above results.

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