• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.2
• /
• pp.138-144
• /
• 2013

Large and small marine accidents which are related to vessel's navigation are happening continuously and these maritime accidents have caused loss of lives and properties, and serious maritime environmental pollution damage. It is also true that maritime pollution damage is increasing due to these accidents, probability of growth of seaborne volume and complicated maritime traffic environment. Korea, recently, is developing an evaluation index which can assess sea risk through the evaluation of maritime traffic environment and provide danger and general information with relation to maritime traffic environment on target sea area to evaluate maritime traffic safety. In this paper, we intend to confirm the validity of maritime traffic safety on the basis of vessel navigator's risk consciousness and various sailing conditions by using the ship handling simulator. To confirm the validity of sailing vessel's maritime traffic safety, we use analysis of variance. By using analysis of variance, we analyze vessel navigator's characteristics, distance, speed and encounter type between vessels. Through multiple comparison of each factor's risk difference, we can confirm the change of numerical value of risk difference in statistical aspect.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.17 no.4
• /
• pp.297-305
• /
• 2014

In this study, we installed the Automatic Identification System (AIS) receiver on the Ieodo Ocean Research Station (IORS) from November 21 to 30, 2013 in order to monitor marine traffic and fishery activity in the jurisdictional sea area. The collected AIS raw data consist of static data report (MMSI, IMO NO., Call Sign, Ship Name, etc.) and position information report (position, speed, course, etc.), and the developed program was applied to classify ships according to ship flag and type information. The nationalities are released from the first three-digit numbers (MID) of MMSI, but in general most of small ships do not send an exact ship flag through Class B type AIS, a simplified and low-power equipment. From AIS data with flag information, ships under the flag of China had the highest frequency and the second was Korean flag, while in ship type cargo and fishing vessels were dominant in sequence. As for the ships without flag information, we compared the tracks with others in order to estimate ship flags. It can be said that fleets of ships with Chinese frequently appear sail together for fisheries over the waters, because the unknown ships followed a similar moving pattern with Chinese fishing vessels.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.6
• /
• pp.587-593
• /
• 2020

The securing safety of ferry ships on the domestic coast is evaluated by comparing the external force applied and the securing device based on the cargo weight and hull acceleration that can exist at the loaded position. The hull acceleration based on the domestic standard, which is the basis for securing safety evaluation, is applied without reflecting the characteristics of the ship and the sailing conditions. In this study, a total of 12 acceleration measurements were performed at four points of the hull of a ship with a DWT 6,800 ton class 15.5 knots passing through Busan-Jeju to analyze the hull acceleration of the domestic coastal ferry ship. Data were collected for the buoy. For a theoretical comparative analysis of the limited measurement results, the response amplitude operator (RAO) was analyzed through frequency-response analysis by numerical simulation, and acceleration analysis for the four points was performed using the RAO results. Based on the acceleration comparison, differences in the degree of each position were observed, but in the case of the Y-axis acceleration, the analysis was 1.81 m/s², and the measurement was 1.47 m/s². The analyzed simulation result was as high as 0.34 m/s². Moreover, analysis was performed at 22 % level, and measurement at 18 % level.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.662-669
• /
• 2018

Recently, the installation of submarine power cables is under consideration due to the increase of electric power usage and the development of the offshore wind farm in island areas, including Jeju. In order to protect power cables installed on the seabed, it is necessary to calculate the burial depth based on the characteristics of anchoring, dragging and fishing, etc. However, there is no design standard related to the size of target ships to protect the cables in Korea. In this study, we analyzed the design standards for the protection of domestic submarine pipelines similar to submarine cables, and developed the risk matrix based on the classification by emergency anchoring considering the installation environment, then designed the size of target ships according to the cumulative function scale by ship size sailing through the sea concerned. Also, we linked marine accident conditions, such as anchoring, dragging, etc. and the environmental conditions such as current, sea-area depth of installation etc. to the criteria of the protection of submarine cable, and examined the size of specific target ships by dividing the operating environment of ships into harbor, coastal and short sea. To confirm the adequacy and availability of the size of target ships, we verified this result by applying to No. 3 submarine power cables, which is to be installed in the section from Wando to Jeju Island. This result is expected to influence in the development of a protection system for submarine cables and pipelines as well as the selection of anchor weight according to the determination of burial depth.

• Journal of Korean Society of Transportation
• /
• v.30 no.5
• /
• pp.91-100
• /
• 2012

Although Korea's coastal areas increasingly experience marine accident due to frequent ship encounters, increased vessel traffic and large vessel, there is a no specific model to evaluate the navigating vessel's risk for the given situation. The maritime transport environmental assessment is necessary due to the amended marine traffic law. However, marine safety diagnosis is now evaluated by foreign models. In this paper, therefore, we suggest a domestic model catering to and reflecting the characteristics of Korea's costal areas as well as those of vessel navigator's risk. We can evaluate subjective risks using this model, and can establish the model output as maritime risk exposure assessment system. We have performed analyses of variance and multiple comparison to identify the factor affecting subjective risks. As a result, measurable subjective risks of maritime traffic accident based on our suggested model can be expressed using the maritime risk exposure assessment system with geographic information system.

• Journal of Navigation and Port Research
• /
• v.34 no.6
• /
• pp.487-492
• /
• 2010

Ulsan Port is the biggest base port for liquid cargoes in Korea and is pushing in earnest for the development of the 'Ulsan New Port' and 'Northeast Asia Oil-Hub' to prepare for continuous shipment growth. However, Ulsan is in the situation which the harbour limit and anchorages are narrower than other trading ports and the occurrence probability of marine accidents is very high due to heavy marine traffic. We will find and suggest the plan to enlarge the harbour limit essentially needed to expand anchorages considering the geomorphological features of Ulsan and the volume of marine traffic in this research. For the enlargement of harbour limit needed to expand anchorages, the anchorage area needed for Ulsan New Port was calculated after the quantitative analysis of enlargement range through the mutual comparison of the area of harbour limit and anchorages with berths and the volume of marine traffic. The reasonable type of harbour limit, which is based on the survey by a group of experts, was also determined after the decision of the range of harbour limit to accommodate the relevant anchorages.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.2
• /
• pp.539-549
• /
• 2016

This study analyzed ship's passing characteristics in relation with incoming and outgoing routes in Yeosu Gwangyang Port, and examined the risk factors and measures for safety management of marine traffic. The number of passing ships in Yeosu Gwangyang Port was about 60,000 ships annually based on 2014, and the tonnage rose 73% from 447,000 thousand tons in 2005 to 770,000 thousand tons in 2014. Actually, the number of large passing ships was revealed to enormously increase. As a result of marine traffic survey in Yeosu Gwangyang Port for three days in August 2015, daily average passing ships were 408 ships, and 77% of the total passing ships passed between 04:00 and 20:00. The chemical ships and general cargo ships took up the most at 58% of the total incoming and outgoing ships, followed by other work ships at 21%, tankers at 8%, fishing vessels at 7.5% and container ships at 5.5%. Concerning the size of passing ships, ships less than 1,000 tons accounted for 58.6% of the total passing ships. Ships of 1,000-5,000 tons were 20.1%, and those of 5,000-10,000 tons were 6.8%, and more than 10,000 tons were 14.4%. Especially, ships of 500 tons and less using mainly coastal passing routes took up 49% of the total passing ships. As for ship's passage ratio by route, Nakpo sea area where many routes meet accounted for 27.2%, specified area 49%, costal route 8%, specified area's incoming and outgoing sea area around Daedo 4.5%, and Dolsan coastal ara and Kumhodo sea area 8.5%. The number of ships standing by for anchoring in the six designated anchorages was 230 for three days. The standby rate for anchoring was 25% based on the specified area passing ships. In Nakpo sea area, where many routes meet, parallel passing and cross passing between ships occurred the most frequently. In the specified area, many cases, in which incoming and outgoing cargo ships at the starting and ending parts and incoming and outgoing work ships and fishing vessels at the coastal routes cross, took place. Consequently, the following measures are urgently needed: active passing management in the Nakpo sea area, where passing routes are complex, specified areas and costal traffic routes, the elimination of rocks in the route close to Myodo, an effort to improve routes including shallow depth area dredging, and rational safety management for small work ships frequently incoming and outgoing the passing routes of large ships, and fishing vessels operated in the sea areas around those passing routes.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.433-438
• /
• 2006

When we consider to develop a new harbor, the most important factor, we think, is the lowest water depth of waterway and approaching channel for safe navigation of vesse. The existing harbors have been being dredged to meet the international trend of jumbo sized vessels by adopting the new design criteria. As the dredged materials over the expected at the design level were common and there are still lack of land based reclamation area, we have no choice to discharge the dredged materials in open sea area. In this study, we analysed the behavior of discharged materials at the dumping area of offshore open sea, which were collected from the dredging work at the waterway in Busan New Port. We measured the tidal currents and analyzed the waters of dumping site after the dumping work. these were used to evaluate the numerical models. Suspended Solids(SS) were introduced to the diffusion model. Because of the characteristics of the dumping site, the speed of initial diffusion and settle down of the discharged materials was so fast. Therefore, we believe that the dumped materials do not cause a significant impact to the marine environment.

• Journal of Navigation and Port Research
• /
• v.37 no.6
• /
• pp.637-645
• /
• 2013

Masan bay with a semi-enclosed waters has serious water quality problems due to the low flow and river pollution load from land, and shows the vulnerable locational characteristics to storm surge. We are seeking the way of both operating disaster prevention facilities and water quality improvement measures in the bay. That is, the water was exchanged using the head difference occurred by operating disaster prevention facilities. The location of disaster prevention facilities was assumed to be in the inlet of the bay, in the vicinity of Machang bridge, and in the vicinity of Dot island and the operation time was assumed to be early morning hours(01~05) considering the number of shipping passage and annual tide, and spring tide of the largest head difference. In addition, the experiment case of water exchange including the in-outflow feeder pipe was tested. According to the simulation results, water exchange rate in all experiments has shown a steady increase. Water exchange rate of the whole of Masan bay in the case of present is 38.62%. The water exchange rate of the inside of Masan bay compared with the inlet of bay, appeared to be very low. Thus, we judged that the characteristics of semi-enclosed waters were well reproduced. On the results of the experiment of disaster prevention facilities and in-outflow feeder pipe, the case of the operation of disaster prevention facilities, water exchage rate is high compared with the case of present. And, the higer the operating frequency, the more water exchange is appeared. The cases of water exchange prevention facilities through the in-outflow feeder pipe caused by the head difference, also showed the higest improvement of the water quality. Compared with the south of Machang bridge, the effect of water exchange was better in the inlet of Masan bay and Dot island. On the other hand, the inlet of Masan bay is higer than Dot island as for water exchange of the whole of Masan bay, but opposite, water change rate including Masan inside was higher in the case of Dot island.