• 제목/요약/키워드: Hauling net

검색결과 46건 처리시간 0.019초

트롤어선의 예망속도 향상을 위한 추진기 구조개선 (Redesigning nozzle propeller of trawl vessel for improving towing speed)

  • 홍진근;강일권;김형석;정성재
    • 수산해양기술연구
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    • 제46권4호
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    • pp.476-486
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    • 2010
  • Fishing efficiency of a trawl vessel can be enhanced by increasing the swept area per unit time, which can be attained either by increasing the mouth size of the net, or by increasing the towing speed. To improve fishing and fuel efficiency of trawl vessels targeting fishes of greater mobility, in which the towing speed is more critical in determining fishing efficiency, we conducted a series of model tests to evaluate the performance of the newly-designed nozzle propeller before installing it in a trawl vessel to verify its towing speed and fuel efficiency in the sea. By conducting further model tests in the experimental basin, we redesigned the propeller of stern trawler to improve the resistance and propulsion performance. Through actual fishing operations, we evaluated the improvement in fuel and fishing efficiency by installing the new nozzle propeller. The trawling speed increased by 0.6kts at the same engine power (RPM), while the engine margin increased by more than 20%. The increased towing speed by installing the redesigned propeller is expected to enhance fishing performance through increasing the number of hauling- and casting operations per unit times, while shortening the towing duration. Analysis of the Catch-Per-Unit-Effort (CPUE) data indicated that the mean CPUE of trawl fishery increased from 3.04kg/m in year 2007 to 6.15kg/m in year 2008, confirming enhanced fishing efficiency by adopting the redesigned propeller.

설문조사를 통한 우리나라 연안복합어선의 조업 실태 (Operating status of Korean coastal composite fishing boats by the questionnaire survey)

  • 황보규;장호영;김민선
    • 수산해양기술연구
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    • 제54권4호
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    • pp.324-332
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    • 2018
  • We conducted a questionnaire survey to analyze the current status of the coastal composite fisheries, as well as the improvement point in designing a new type coastal composite fishing boat suitable for Korean fishing environments from April to August 2017. The questionnaire composed of 20 questions about the features of the coastal composite fishing boat and fishing work. The survey sites were selected to cover all parts of the country by considering the geographical position. The significance testing for the response results was accessed by ${\chi}^2$ test and ANOVA. The results revealed that more than half (59.1%) of the fishermen operated one day per voyage and operating alone topped with 22.5% in the number of crews, followed by 2 persons (20.3%) and 5 persons (22.1%). The navigation devices had a high rate of installation and GPS plotter ranked first in the devices. In addition, fish finder ranked first in fishing equipment, followed by net hauler. The most inconvenient work that they felt during the fishing operation was fish handing at 49.8% and other general fishing works like setting and hauling line, deck cleaning accounted for about 25%. The hardest work was the accident by ropes wrapped around propeller and the engine trouble came in second. The most inconvenient facilities to the present design of fishing boat was wheelhouse (76.7%), followed by fish hold (38.5%), and deck (35.1%). Furthermore, inconvenient points related to the movement of fishing gear, noise and vibration of engine, slippery deck and small fish hold exceeded 50%.

우리나라 다랑어선망어선의 어선원 안전 위험요소 분석 (Analysis of safety risk factors of fishermen on the Korean tuna purse seiner)

  • 김오태;조현수;장호영;이유원
    • 수산해양기술연구
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    • 제58권3호
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    • pp.251-261
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    • 2022
  • Tuna purse seine fishery (TPF) constitute more than 60% of distant water fishery production in Korea based on a statistic of 2018, and 28 ships from four different companies were under operation at the western and central Pacific Ocean. On this research, common risk factors during TPF were investigated via enumeration of five years Korean fisherman's insurance payment statement, followed by some counterplans to diminish the accident rate. The accident rate of TPF on the Pacific Ocean peaked by 43.0% in 2014 and constantly decreased to 23.0% until 2018, presenting an average of 33.6%. Meanwhile, the accident rate on the Indian Ocean reached the highest point 55.1% in 2014 and declined to 11.6% in 2016, having an average of 24.7%. The average accident rate of the Indian Ocean scored 8.9% lower than the rate of the Pacific Ocean, but no statistic significance was observed. Depending on the process of operation, 'casting or hauling of net' was the most frequent part that people received an injury (40.4%). When the accidents were classified by their types, 'falling down' was the most recurrent cause of the injuries (28.5%). At the point of severity, the worst injuries were induced by crush hazard. Considering aforementioned accident frequency and severity, all the factors on the accident type list were divided into three different groups including high risk, moderate risk, and common risk. This study is expected to contribute to the reduction of occupational accidents during the work of fishermen and establishment of a safety management system for distance water fishing vessels.

우리나라 근해 대형트롤 어선의 갑판 레이아웃 차이에 따른 어로작업의 비교 분석 (Comparative analysis of fishing operation with the difference of deck layout of Korean coastal large trawler)

  • 김민선;강경미;이주희;신현옥
    • 수산해양기술연구
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    • 제49권3호
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    • pp.311-326
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    • 2013
  • For providing a basic data concerning with a fishing deck layout design of a trawler the authors conducted the video observations about the working activities of crews on the deck in the different layout of two Korean coastal large stern trawlers (gross tonnage: 139). The winch of the trawler-A was installed on the aft of the fishing deck and the trawler-B, on the forward of the fishing deck. The work and activities of the deck hands on both trawlers were observed using the CCD (charge coupled device) camera installed on each trawler's deck for one month from August 3, 2010. The video data was analyzed by the hierarchical task analysis (HTA) method. In results, numbers of tasks to require deck hands during the hauling net and the casting net were 25 and 28 for the trawler-A and 27 and 48 for the trawler-B, respectively. The working processes were represented a same in both of the trawlers. Location for controlling the deck machineries, the location installed trawl winch, kinds of deck machineries, crew's custom for using deck machineries were the factor affecting to the number of the task. In the case of the improvement suggested in the results is carried out, the reduction percentages of the number of task in the trawler-A and trawler-B were estimated as 24.5% and 51.3%, respectively. Through this study it was found that the quantitative analysis is possible for the work processes, work methods and the work contents in the trawler. Also the suggestion for improving the fishing deck layout design of the trawler was possible by finding out the factors increasing the number of tasks and removing the tasks. We expect that the results of this paper are used as a basic data for designing the layout of deck machineries in the trawler in the future.

巾着網漁船의 船型과 操船의 基礎的 硏究 (A Fundamental Study on the Types of Ship and the Steerage of Purse Seiners)

  • 김진건
    • 수산해양기술연구
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    • 제30권1호
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    • pp.13-24
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    • 1994
  • Purse seiner detects a fish school navigating in full speed with the aid of fish finder, sonar, helicopter, etc., and casts a net quickly to enclose the fish school in purse seine net according to the movement of the fish school, wind, and current. At this moment, if the time of casting a net, direction, speed, and turning circle are net suitable, it is unavoidable to lose fish school founded with hard efforts and we only consume our efforts of casting and hauling the net. Therefore, in order to enclose the fish school to enhance the amount of fish for each casting, the author investigated the type of ships equipped with purse seiners and examined maneuvering tests so that we provide some basic information to figure out the ability of steerage correctly. The results obtained are summarized as follows: 1. Block coefficients of pelagic tuna purse seiners with gross tonnage between 500 and 1500 tons are recorded between 0.50 and 0.55 which are greater than those of off shore purse seiners recorded as between 0.44 and 0.54 and less than those of various cargo ships recorded as between 0.56 and 0.84. 2. L/B, L/D, B/D, B/T, and T/D of the class of gross tonnage between 75 and 130 tons are respectively 4.49, 11.00, 2.45, 2.85 and 0.86 as their average and those of the class of between 500 and 1500 tons are 4.89, 10.53, 2.15, 2.73 and 0.75 respectively, which are quite different from those of various cargo ships recorded as 6.0~7.5, 11.0~12.0, 1.6~2.0, 2.2~2.8 and 0.65~0.75 respectively. 3. Rudder area ratio of purse seiners of the class of between 75 and 130 tons is 1/24~1/31 and that of the clase of between 500 and 1500 tons is 1/36~1/42 which is greater than that of various cargo ships recorded as 1.45~1.75. 4. On speed-length ratio of purse seiners. 111 Dong-a has the biggest value 2.94 the class of 130 tons has 2.52 the class of between 75 and 100 tons has 2.30~2.35 and the class of between 500 and 1500 tons has 1.99~2.05. 5. Turning circle of stern trawlers Pusan 404 and Haelim 3 are measured as below according to rudder angles 5$^{\circ}$, 15$^{\circ}$, 25$^{\circ}$ and 35$^{\circ}$ respectively. Advances are 11.3~13.6, 6.0~7.1, 3.6~4.8 and 2.5~3.5 times of LPP respectively. Tactial diameters are 15.2~18.6, 6.9~8.0, 4.2~4.9 and 2.9~3.5 times of LPP. Purse seiner 111 Dong-a with rudder angle 35$^{\circ}$ has a good yaw with quick responsibility since its advance is 2.2~2.3 times of LPP and since its tactial diameter is 2.0~2.1 times of LPP. 6. In full ahead going of purse seiner 111 Dong-a, it takes about 2 minutes and 10.6 times of LPP from the reverse turning its engine into full astern to the ship speed 0. In its full astern going, it takes about 1 minute and 5.1 times of LPP from the reverse turning its engine into full ahead to the ship speed 0. In its full ahead going, it takes about 2 minutes and 50 seconds and 12.3 times of LPP from stopping its engine to the dead slow ahead speed 3.2 knots.

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강북연안 정치망 어획량 변동에 관한 연구 (The Fluctuations of Catches in Set Nets Around Kyeongbuk Province)

  • 홍정표;이주희
    • 수산해양기술연구
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    • 제31권2호
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    • pp.153-165
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    • 1995
  • 경북 연안 정치망어업의 어획량 변동에 관한 연구를 위하여 1985~1989 연간 총 11통의 표본어장의 어획자료로부터 연도별, 월별, 지역별, 어종별, CPUE(1양망당 어획량), 어종조성 및 각 어장별 주요어종의 출현시기 및 해황 특징 등에 관한 연구 결과를 요약하면 다음과 같다. CPUE 변동은 연도별로 보면, 변동폭이 매우 크고 대체적으로 감소하는 경향이고, 지역별로는 죽변 지역이 높고 나머지 지역은 낮았다. 월별로 보면, 전체적으로는 8~11월이 높게 나타났고, 지역별로는 주변, 강구는 8~11월, 축산, 감포는 9~11월, 후포는 8~12월이 높게 나타났다. 연도별 CPUE 변동은 연도별로는 쥐치, 고등어, 참다랭이, 조피볼락, 방어는 감소 추세에 있고, 정어리, 전갱이, 청어는 증가 추세에 있으며, 오징어는 안정을 유지하면서 증가하는 경향에 있고, 갑오징어는 1987년 이후 낮은 수준에서 안정된 경향을 보였다. 월별로는 고등어, 전갱이, 참다랭이, 방어, 조피볼락은 9~10월, 쥐치와 오징어는 11~1월, 정어리는 4~5월, 청어는 3월, 갑오징어는 4월이 높게 나타났다. 연도별로 출현하는 주요어종의 어군크기는 1985년~1989년 전체적으로 볼 때 쥐치, 정어리, 전갱이, 고등어, 오징어, 참다랭이, 방어의 순 이였고, 연도별로는 1985년 쥐치, 1986년 정어리, 1987년에는 전갱이, 1988년에는 쥐치, 1989년에는 정어리가, 월별로는 1~7월까지는 정어리가, 8~10월에는 정어리, 고등어가, 그리고 11~12월에는 쥐치가 수위를 차지하고 있었다. 어종별 출현시기를 감포와 죽변 지역을 비교해 볼 때, 쥐치, 고등어, 오징어, 참다랭이, 갑오징어는 죽변 지역이 다소 빠르게 나타나고, 고등어와 방어는 감포 지역이 빠르게 나타났다. 특히 정어리의 경우는 출현시기가 약 3개월 차이를 보인 반면, 전갱이와 삼치는 동일한 시기에 출현하였다. 또한 경북 연안 정치망어업에서는 평년에 비해 난류세력이 강하고 수온전선이 연안을 따라 남북으로 길게 형성되는 해에 해황이 좋은 것으로 나타났다.

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