• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.1-6
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• 2015

In this study, with the awareness of the limitations set in the currently operated calculations of holding power and the holding power coefficient of anchors of naval ships due to its simple application of a specific value, various factors that impact the holding power and its coefficient were verified based on existing data analysis of literature research and numerous experiment results from anchor manufacturers, research institutes and academic community in order to overcome the aforementioned limitations. In addition, holding power and holding power coefficient were compared and analyzed by the shape of anchors. As a result, we came to know that the holding power of AC-14 type anchor is stronger than that of ASS type anchor or U.S. Navy Standard type anchor which makes it possible to reduce the weight of the anchor and therefore ease the process of naval shipbuilding. Furthermore, we confirmed the fact that U.S. Navy Standard type anchor does not react sensitively to the weight change of the anchor. Lastly, we found out that Danforth type anchor's holding power coefficient is in inverse proportion to the weight. Moreover, instructions for managing anchor are arranged easily for your information. The results of this study is expected to provide anchor - operating naval crew with a reliable theoretical basis pertaining to an anchor's holding power and its coefficient and contribute much for the safety of their act of anchoring.

• Journal of Navigation and Port Research
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• v.35 no.8
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• pp.613-618
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• 2011

Vessels on anchoring are sometimes dragged due to the increased external forces. For preventing the dragging, it is required to enhance the holding power of the anchor. The holding power depends on the type and weight of the anchor and the seabed condition. Especially, the holding power of AC-14 type anchor is known to be 2~2.5 times bigger than that of ASS type anchor. However, these coefficients was determined nearly by the result of the model test, so there is a need to verify that by sea trial. Therefore actual dragging case was analyzed and then compared with the coefficients in use, it was found that the two of them are much alike.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.683-688
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• 2014

The vessel should prevent dragging anchor against the external forces by utilizing the anchor and secure the stability of it. A fundamental understanding on the embedding motion and holding power of the anchor is necessary to perform the safe operating of anchor work. In this study, the embedding motion and holding power of the anchor according to an initial position in an experimental tank of 6m long in sand are tested by using two types of different anchor models(ASS and AC-14), which are generally applied to the commercial vessel nowadays. The anchor flukes seem to rotate and to be embedded into soil up to the maximum depth and maintaining a constant depth in case of the same direction and perpendicular to the towing direction, regardless of the form of an anchor. In case of the opposite direction to the towing direction, it is noted that the coefficient of holding power becomes smaller than the other initial positions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.95-105
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• 2001

A series of experiment is carried out to determine the holding power of the existing anchors used in the stationary gear in the coast of the South sea. The experiment apparatus is made of the pulling machine, the load cell, the personal computer and three water tanks the bottom of which are mud, sand and m & s respectively. The result obtained are as follows : 1. On the tension and holding power of the existing anchors, B-type of the stock anchor with two fluke shows the greatest and gets smaller on order of A-type one with a fluke. The holding power of the anchors shows the greatest in the mud and gets smaller in order of m & s, sand. And, the holding power depending upon the length of anchor rope increase as the length does up to the 4 times of depth. 2. On the holding power per fluke area of the existing anchors in case of ration of length of anchor rope to depth is 2, 3 and 4, A-type anchor shows about 310-320 kg/m supper(2), 470-480 kg/m supper(2), 590-640 kg/m supper(2) respectively, B-type one 260-265 kg/m supper(2), 390-450 kg/m supper(2), 630-700 kg/m supper(2) respectively, and C-type one 70-100 kg/m supper(2), 150-180 kg/m supper(2), 210-270 kg/m supper(2) respectively. The holding power per fluke area of the anchors increase as the length of anchor rope does. 3. On the coefficient of holding power of the existing anchors, A-type anchor shows the greatest and gets smaller in the order of B-type one, C-type one.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.309-316
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• 2017

In this paper, numerical modeling is conducted to analyze the tension of an anchor line by varying the size and drag coefficient of a buoy when the trapnet is influenced by the wave and the current simultaneously. A mass-spring model was used to analyze the behavior of trapnet underwater under the influence of waves and current. In the simulation of numerical model, wave height of 3, 4, 5 and 6 m, a period of 4.4 s, and the flow speed of 0.7 m/s were used for the wave and current condition. The drag coefficients of buoy were 0.8, 0.4 and 0.2, respectively. The size of buoy was 100, 50 and 25% based on the cylindrical buoy ($0.0311m^3$) used for swimming crab trap. The drag coefficient of the trapnet, the main model for numerical analysis, was obtained by a circular water channel experiment using a 6-component load cell. As a result of the simulation, the tension of the anchor line decreased proportional to buoy's drag coefficient and size; the higher the wave height, the greater the decrease rate of the tension. When the buoy drag coefficient and size decreased to one fourth, the tension of the anchor line decreased to a half and the tension of the anchor line was lower than the holding power of the anchor even at 6 m of wave height. Therefore, reducing the buoy drag coefficient and size appropriately reduces the trapnet load from the wave, which also reduces the possibility of trapnet loss.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.23-24
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• 2013

본 연구에서는 해군함정에서 투묘 시 함정별 묘의 파주계수와 그에 파주력 그리고 외력의 세기를 고려한 묘쇄의 적정 신출량을 구할 수 있는 수리모델을 정립하여 제시하고, 이것을 해군이 보유하고 있는 전 함정 승조원들로 하여금 쉽게 사용할 수 있는 적정 묘쇄 신출량을 그래프한 자료를 제시하였다. 본 연구 결과는 해군함정이 투묘시 바로 적용될 수 있을 뿐만 아니라, 이론적인 근거를 제공하는 참고자료로 유용하게 활용될 수 있을 것이다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.600-613
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• 2015

The Fishing gear loss has been repeated every year in the West Sea; however, there has been no solution. So fisher men have undergone economic loss every year. Thus it is required to reduce the loss of fishing gear. In this study to find out the reason that the fishing gear is lost in the Sea, 10 years data of wave and current for 6 locations in the West Sea were investigated and a numerical modelling were conducted into the behaviour of a gillnet in wave and current. The fishing gear was modelled with the mass spring model. As a result, it came out into the open that the location where fishing gear loss occurred most frequently was Choongnam province. The height of the maximum significant wave in this province was 6.7 m and the period of that was 4.4 second. The maximum current speed was 0.7 m/s. As a result of simulation with these data, it was revealed that the buoy is one of the reasons to decrease the holding power of the gillnet. For example, the tension of anchor rope was decreased to 50% while the drag coefficient or volume of buoy was decreased to 25%. So it is predicted that an improvement of the buoy contributes to the reduction of the gillnet loss.

• Women's Health Nursing
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• v.2 no.1
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• pp.5-24
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• 1996

The Delivery Process can be viewed as one of the developmental crisis that forces the majority of women. During the labor and delivery process the women may face a variety of problems and pain with all its subjectivity. This developmental crisis may lead a pregnant women to have a negative experience in delivery. For nurses, to help to pregnant women check with the crisis and perceived support and to positive experience. This study intended to analyze the pregnant women's delivery experience according to supporter during labor. The subjects for this study were 45 pregnant women who had normal delivery without complications, within 37 to 42 weeks of pregnancy. Data Collection was done from April 24th to May 20th 1995 by two instruments, a support measurement scale and a delivery experience measurement scale which were consisted it 18-items scale developed by researcher. The data was analyzed by SPPS program using descriptive statistic Kruskal-Wallis one way analysis and Spearman Correlation Coefficient. The result of this study are as follows. 1. Support distribution by support contents is shown is order of holding the hands (97.8%), help to urination(86.7%), bed arrangement(57.8%), massaging the arms and legs(55.6%), changes in posture(44.4%), teaching how to produce power(44.4%), while emotional support is disclosed in order of sympathy(97.8%), encouragement(82.2%), hearing the needs(60.0%), However, information support was as low as less than 33.3%. 2. The extent of delivery experience a Pregnant woman perceives is revealed in order of a sense of comfortableness(44%), satisfaction(43.2%), reduction of fear(43.2%), familiarity (42.8%), self-confidence (42.5%), decrease of laborpain(39.9%). 3. The extent of delivery support a pregnant woman perceives reveals that physical support($x^2$=22.4452, P=.000) and information support($x^2$=7.5187, P=.0233) Show a significant difference among the mothers group, the mothers-in-law group, the husbands group, but to significant difference was found in emotional support among them. 4. The extent of delivery experience a pregnant woman perceives represents a significant difference in order of the mothers group, the mothers in-law group, and the husbands group($x^2$=13.4255, P=.0012). 5. A positive correlation was manifested between the extent of support and delivery experience a pregnant woman perceives(r=.8643, P=.000). This information can be utilized as data to further the understanding delivery experience according to supporter. In Consequence, it is recommended that the range of family support limited to husband should be expended including mother and mother-in-law.