• 대한조선학회논문집
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• 제48권2호
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• pp.158-164
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• 2011

The study on the improvement of resistance performance is very important for coastal fishing boats in Korea, because the prices of fuel oil are gradually risen and the demand of high-speed fishing boats is increased lately. This study is concerned with the improvement of the resistance performance for Korean high-speed small coastal fishing boats. A semi-planing hull form of Korean small coastal fishing boat is selected in the role of initial hull. From the modification of the hull form parameters and the local characteristics of the hull form, the improvement of the resistance performance is achieved. The resistance performances of the initial and the modified hull forms are estimated by using a numerical simulation method. Also, ship model tests are carried out in ship model basin.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.232-233
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• 2005

Stainless steel has been stably used closed by passivity oxidation films($Cr_2O_3$) is made by neutral atmospheric environment. However, passivity oxidation films of the surface of stainless steel occasionally comes to be destroyed in seawater which is influenced by an environment having halogen ion like $Cl^-$, then, localization corrosion comes to occur. Stainless steel 304 for shaft system material of the small-size FRP fishing boat on seawater environments made an experiment on simulation of sacrifical anode(Al, Zn). Through these experiment and study, following results have been obtained ; According to the field inspection and corrosion simulation, the corrosion on the 2nd class stainless steel shaft(STS 304) in FRP fishing boat has been verified to occur by crevice corrosion and galvanic corrosion etc.. According to the comparison and analysis of Stainless steel 304 shaft materials after simulation leaving unprotected and applying cathodic protection, unprotected shaft specimen of stainless steel 304 was severely corroded, but, protected shaft specimen was not totally corroded. This result is assumed to be made by the facts that anodic reaction, $Fe{\rightarrow}Fe^{2+}$ + $2e^-$, has been restricted by the cathodic protection current of sacrificial anode material.

• 대한조선학회논문집
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• 제60권3호
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• pp.175-185
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• 2023

Many small vessels such as fishing boats operate in the world's oceans; accordingly, interest in these small vessels' exhaust-gas problem is increasing. Research on the application of electric-propulsion technology has been steadily conducted; however, the subject is limited to research ships or leisure boats, while research on application efficiency remains insufficient. This study attempts to apply lithium-battery electric-propulsion technology to small ships. A gross tonnage of 9.77, a representative fishing boat, is to be redesigned as a fully electrified ship. Without changing the main cabin's dimensions and fuel tanks, the ship's propulsion system is redesigned based on a lithium-battery electric-propulsion system. In addition, the redesigned system is compared with the original sample ship's diesel-propulsion system for application-effect analysis. The results indicate that under controlled sailing conditions, the weight and volume of the electric-propulsion system are 9.5 and 10.5 times those of the diesel-propulsion system, respectively. These values indicate that the system cannot meet fishing boats' high endurance requirements. Therefore, under the existing technical conditions, applying the full lithium-battery electric-propulsion system to solve the problem of high emissions from fishing boats shows limited feasibility.

• 한국항해항만학회지
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• 제32권3호
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• pp.223-228
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• 2008

한국에서 건조되는 대부분의 소형 연안 어선의 경우 경험에 기초하여 건조되어지기 때문에 구조적 안전성 문제가 발생하곤 했다. 본 논문에서는 이들 어선의 구조강도를 증가시키고 생산 및 운용비를 줄이기 위하여 최적설계를 수행하였다. 어선의 무게와 구조부재의 주요치수들을 각각 목적함수와 설계변수로 선택하였다. 해석과정 중에 극소점을 피하고 CPU 시간을 줄이고자 전역 탐색법과 지역 탐색법을 결합한 하이브리드 최적화 알고리즘이 개발되었다. 또한 최적화 루프의 각 iteration 단계에서 제한조건을 결정하기 위하여 유한요소해석을 수행하였다. 최적화 결과는 초기 어선 모델과 비교하였으며 최적설계의 효과가 구조강도, 재료비 관점에서 검토되었다.

• 한국항해학회지
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• 제19권1호
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• pp.1-8
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• 1995

The motion of a small boat in seas is affected in relatively higher degrees than the case of a larger ship by the specific characteristics of sea waves, i.e., the wave length and height. Ship's motion caused by sea waves is a matter of special importance to small fishing boats, because they carry out fishing job in rough seas frequently. This is an experimental study on the rolling and pitching motions of full scale ship. In the experiment, the ship's motions were measured for head, how, beam, quarter and following seas. The experiment were carried out on board the training ship Pusan 404(160 GT) in the adjacent waters off NAM HYENG JAE DO on Dec. 13th 1994. The sea condition during the measurements was that wave height 2.5m, no swell and the wind velocity of 12 m/sec. Some statistic considerations were given to the observed data by the series analysis methods and discussed in this paper.

• 대한조선학회논문집
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• 제51권6호
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• pp.521-529
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• 2014

In this study, numerical simulations and model tests are performed for the hull-form development of a G/T 29ton class coastal angling fishing boat. The numerical simulations are mainly used for the design of bow hull-form and the resistance performance is improved by the adoption of high bulbous bow. And, the resistance performances of the existing boat and the designed boat are verified by the model tests. The results of the experiments and calculations show that the effective power of the designed boat is 13.6% less than that of the existing boat at design speed. Therefore, the results of this research could be used as one of the fundamental data for the design of G/T 29ton class coastal angling fishing boat.

• 해양환경안전학회지
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• 제26권1호
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• pp.22-30
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• 2020

2016년 3월 6.67톤 어선이 크레인 작업을 하던 중 복원성 상실로 인한 전복 사고가 발생하였다. 전복은 충돌, 접촉, 좌초, 화재 및 폭발의 결과로 발생한 사고는 제외하고 선박이 뒤집힌 것을 말한다. 지난 9년동안(2010-2018), 전복 사고는 전체 해양사고의 2.34%를 차지하고 있으며 증가와 감소를 반복하고 있다. 10톤 미만 소형어선의 주된 전복사고 원인은 부적절한 선적에 따른 복원성 상실이다. 어선법에 따르면 소형 어선은 복원성과 1톤 미만 제한 하중 크레인에 대해서 복원성과 예비검사를 면제해 주고 있다. 본 연구는 고성에서 발생한 소형 어선의 전복 사고 재결서의 원인으로 언급된 사항 중 크레인 증량에 따른 복원 모멘트 감소에 대해 실제 제원이 비슷한 어선을 모델링하여 이를 통해 사고 전·후의 어선 상태를 가상하여 복원성을 비교하였다. 그 결과 기존 보다 무거운 크레인으로의 교체 시에는 복원 모멘트 감소와 현단몰입각의 감소로 전복의 위험성이 증가되었다. 표준재화 상태에서는 입·출항시 보다는 어로 활동을 하고 있는 상황에서의 복원 모멘트가 감소되는 것을 확인하였다.

• 한국기계기술학회지
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• 제13권4호
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• pp.63-69
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• 2011

Hull forms for catamaran type small fishing boat powered by electric motor are newly developed by experimental approaches. Model tests for two hull forms having different length are made at circulating water channel. Resistance performance and wave patterns are compared to carry out an analysis of the effect of extension of main body. The results show that the extension of main body can give better resistance performance above a certain velocity.

• 대한조선학회지
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• 제8권1호
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• pp.17-28
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• 1971

The coefficients of equations of heave, pitch and coupled motion are evaluated for the small typical fishing boat(KIST-MARK Fishing Boat) with transom stern in regular head sea. And the results of computations based on eight models of strip theory are compared one another for the forward speed Froude number 0.30. There are some distinctive differences among those theories for the hydrodynamic and coupling coefficients. The former seems to be caused by the effects of the transom stern and the latter of the foward speed.

• 수산해양기술연구
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• 제45권4호
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• pp.267-275
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• 2009

According to the recent statistics of marine casualties in Korea, fishing boats are more likely to be ended in the casualties, and small fishing boats especially cause much more accidents in sinking and capsizing than any other big vessels. These casualties were mainly produced from the ignorance on the lack of own ship stability. From this view, this study aims to analyze the characteristics of stability on the crab trap fishing boat receiving transverse wave by means of carrying out the water tank test. The rolling angle of the model ship was affected largely with the displacement and the wave period of it, and the trends were shown that the magnitude of the angle was proportional to the displacement, but inversely to the wave period. And the wave height had effect on the rolling angle just in the specific range of the wave period. The force of steady wind didn't have influence on the rolling variation significantly.