• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.58 no.1
• /
• pp.10-18
• /
• 2022

Fishery sea anchor is widely used for many fishing vessels. However, standardization of the dimension and terminology of the fishery sea anchor has not been achieved, reducing the reliability of the performance and safety of the fishery sea anchor. Therefore, this study researches the reality of usage of fishery sea anchor and then attempts to suggest the development direction of the standard draft as basic data. As a result of the survey on the reality of usage show that various terms were used for each part of the fishery sea anchor (including the incorrect form of non-standard words derived from Japanese) and that the production of this product in the fishery sea anchor market was concentrated on one specific manufacturer. In addition, the main specifications of the fishery sea anchor are set and manufactured based on conventional experience without standards. In the field, there was no standardized drawing for fishery sea anchor and users had low awareness of the main specifications of fishery sea anchor. Therefore, this study suggested the following regarding the fishery sea anchor: standard terms for each part including Korean and English names and standard drawing of sea anchor. It is hoped that this study will contribute to research for the standardization of fishery sea anchor, which will increase in reliability and lead to increased interest in standardization in the fishery field.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.58 no.4
• /
• pp.289-298
• /
• 2022

Sea anchor for fishery is commonly used in jigging fishery and purse seine. The study of sea anchor was studied for improvement of opening efficiency and drag by changing the type of shape and the diameter of vent. However, standard specification of sea anchor is not set and has not been studied for underwater stability. Therefore, this study aimed to improve underwater stability of sea anchor by changing a vent diameter and weight of sinker. The experiment was conducted in flume water tank. The experiment model of sea anchor was made from actual model of sea anchor which is used in fishery by similarity law. The model of sea anchor was designed to different types of vent diameter and weight of sinker in different current speed. The value of movement of side to side (X-axis), drag of sea anchor (Y-axis) and movement of up and down (Z-axis) was measured for 30 seconds. Each value of X, Y, Z-axis was analyzed through t-test and ANOVA analysis to verify that each value had a significant difference according to the difference compositions. There was correlation between the movement of X-axis and Z-axis. The drag of sea anchor was stronger as the current speed increased. However, the larger the vent diameter, the weaker the drag. From the result of the standard deviation, the movement of X-axis was inversely proportional to the vent diameter. However, movement of Z-axis was larger as the weight of sinker was the heaviest or lightest from the result of the standard deviation. These results suggest that the sea anchor should be combined with proper size of the vent diameter and the weight of sinker to improve the stability.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.59 no.2
• /
• pp.110-116
• /
• 2023

In this study, samples of sea anchor canopy cloth mainly used in Korean jigging fishing vessels were collected and tested for performance evaluation. The canopy cloth of sea anchor is a basic element of form composition that is known to have the greatest influence on anchor performance. In order to evaluate the performance of sea anchor canopy cloth, five types of samples were tested for new metric count, tensile strength, water vapour transmission rate and drying speed according to the national standard (KS), and some correlations were identified. As a result of the test, the new metric count of cloths was 335.5-443.4 denier in warp and 217-447.6 denier in weft, and the minimum tensile strength was 860 N in warp direction and 430 N in weft direction. The apparent number and tensile strength of cloth were proportional, the water vapour transmission rate of the sample was 206.8 g/m²h, and the drying speed was 90-100 min. This study partially confirmed the performance evaluation based on speculation by the standard test method, and further research is needed on the clear relationship between the research results and the performance of the sea anchor.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.22 no.8
• /
• pp.1041-1051
• /
• 1998

The fluid dynamic properties of a circular arc type sea anchor were calculated by a discrete vortex method. The flow for the surface of the sea anchor was represented by arranging bound vortices at adequate intervals. The simulations were performed by assuming that the separations occur at edges. With time, the drag coefficient was almost constant but the lift coefficient oscillated in a cycle by von Karman's vortex street. As the camber ratios increase, the drag coefficient and Strouhal number were almost constant but the oscillating amplitude of the lift coefficient increased largely.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.6 no.1
• /
• pp.77-83
• /
• 2000

En coastal area, many submarine facilities such as pipes and cables are installed on/under the sea bed. Also, there are heavy traffic due to numerous vessels which call in ports or navigate passages in adjacent water. Therefore, the frequency of dropping anchors will be increased to avoid various dangerous situations. When an anchor is dropped from vessel on the sea bed, the anchor strikes on the sea bed, and then, the anchor penetrates to certain depth into the sea bed. In this case, sometimes submarine facilities on/under the sea bed may be damaged by the strike or the maximum penetrating depth of anchor. In this paper, some approximate equations on the strike and the penetrating depth of anchors have been derived on the basis of actual data, and the results are expected to use as basic design data of related facilities.

• Journal of Advanced Marine Engineering and Technology
• /
• v.28 no.8
• /
• pp.1258-1269
• /
• 2004

The fluid dynamic characteristics of a circular arc type sea anchor were calculated by a discrete vortex method. The flow for the surface of the sea anchor was represented by arranging bound vortices at adequate intervals. The simulations were performed by assuming that the separations occur at edges. With time, the drag coefficient was almost constant but the lift coefficient oscillated in a cycle due to von Karman's vortex street. As the camber ratios increase, the drag coefficient and Strouhal number were almost constant but the oscillating amplitude of the lift coefficient increased largely.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.32 no.2
• /
• pp.132-147
• /
• 1996

The optimal design of floating type fisheries facilities in the open sea is demanded considering with the severe hydrodynamic forces on floating body, mooring tension and holding force of anchor. For conserving the facilities in most effective state, design and selection of anchor system is one of the most important fundamental subject. To enhance the design procedure of anchor system the holding forces of anchor are investigated by the hydraulic model test and are compared with the typical conventional results for various anchors. Applicability of previous estimation methods of holding force are checked and holding mechanism of anchor is discussed. Using the results a new computational concept of holding force is suggested considering mainly the effects of passive soil pressure (resistance), steady soil pressure, and surface friction etc. The new estimation method is proved as a feasible one by comparing the results of hydraulic model experiments. Applicability of various anchors to the anchor system on open sea fisheries structures is comprehensively reviewed using the present model tests and previous study results in the viewpoint of economy, construction and stability etc. Using the results, fundamental anchoring system design procedures are suggested to apply huge marine ranching complex with increase of the holding capacity of anchor under the optimum cost.

• Journal of Ocean Engineering and Technology
• /
• v.31 no.4
• /
• pp.308-314
• /
• 2017

The purpose of this study was to investigate the sea floor using a seismic profiler in the northern part of Chagwi-do of Jeju Island in order to select the optimal location for the 60-m-class berth of a sea test bed for wave energy converters and provide basic environmental data for designing a suction anchor. The echo types of the seismic profiles were classified based on the study of Kim et al. (2016a), and the location for installing the suction anchor was selected based on a sediment thickness of more than 10 m. The physical properties of the surface sediments were determined by analyzing the sediment samples obtained from 16 grab sample points. Based on the investigation and analysis, we proposed a survey area in the North-Eastern sea as an optimum location for the 60-m-class berth where the suction anchor could be installed.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.6
• /
• pp.1761-1771
• /
• 2016

In respect of the existing relation between Sea-going Vessels and Vessels at anchor, Korean Maritime Safety Tribunal has applied 'Ordinary Practice of Seamen' that is regulated by the article No. 2 of COLREG. That is, general navigation rule is not applied between the two vessels, and the action to avoid collision of vessels by utilizing experience knowledge of the seamen. However, the content of the Ordinary Practice of Seamen included in the revised plan in the process of 2011 "Maritime affairs Safety Act" revision was deleted in the screening of the Office of Legislation due to the reason that it could not specified when the content of deed is not concertized. Furthermore, prior application regulation of international treaty included in the existing "Sea Traffic Safety Act"(Article 5) was deleted in the screening of the National Assembly. So, doubt about whether the Ordinary Practice of Seamen could be continuously applied according to the regulation of the international treaty, nevertheless not specified in domestic law, has been continuously raised. In this situation, recently Central Maritime Safety Tribunal changed precedent by applying of Article 96(3) of Maritime Safety Act without applying Ordinary Practice of Seamen in the Case No. 2015-001. Accordingly, this study intended to review propriety of precedent change and legal issue with the decision of Central Maritime Safety Tribunal excluding Ordinary Practice of Seamen for a collision between Sea-going Vessels and Vessels at anchor.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.4
• /
• pp.6-22
• /
• 2022

In this paper classifies the types of 228 anchor stones discharged from the west and south coasts, assumes a combined method by type, routes through discharge locations, and It attempted to estimate the burial site. Prior to classification of types, the weight, thickness, width, and length of the anchor stone were measured, and the largest Young in the tomb The scent weight was classified into I~V groups, and the shape of the anchor stone was classified into 1-6 types. All of these weight and shape correlations It was classified into 17 types. The combined method by type is 180kg or less depending on the morphological characteristics of the reference value of the extracted anchor stone, and the type An anchor of type 1 or 2 is used in combination with an anchor, and a anchor of type 3 or 6 weighs more than 180kg and is combined with an anchor The dragon was assumed to be an anchor. Along with this, the route and burial site are identified through past records and testimony of local residents It was checked against the data. The route was largely consistent with past records, but the new route was apparent in waters near the island or inland It was also drawn. In the case of burial sites, small and large in Taean Mado Sea and Jindo Byeokpajin Sea, where anchor stones are concentrated, Considering the pattern of the type anchor stones being discharged, it was consistent with the testimony that ships of various sizes were mysterious in the two seas. Based on this type classification, a study on the spatiality of the anchors was conducted. First, a comparison and analysis was done on whether actual real data, such as anchor stones, old ships, and relics, were identified on the Joun-ro route and international trade routes as recorded in the past literature. Where there was no record, the route was estimated based on real data. To this end, routes estimated based on the testimony of local residents and modern ship workers were analyzed as to whether ships traveled there in the past and whether they could actually sail. Next, the location of each seedling was estimated by ship size according to the weight of the anchor stone. In the case of the Taean Mado Sea and Jindo Byeokpajin Sea, both small and large anchor stones were discharged from the coastline and were far away.