• Journal of the Society of Naval Architects of Korea
• /
• v.55 no.2
• /
• pp.144-152
• /
• 2018

This study aims to establish a mathematical formula to provide rapid and safety estimation of the damaged double hull tankers under ship-ship collision. Difference in heights between the striking and struck ships 'h' and penetration depth 'x' were considered as the main parameters. In ship-ship interaction, Large oil tankers are selected as target struck vessels, and they are struck by Very Large Crude-Oil Carrier (VLCC) class oil tanker. The residual strength of damaged ship at several locations and collision scenarios were carried out using Intelligent Supersize Finite Element Method (ISFEM) which considers the progressive collapse behavior of ship hulls strength. Based on these results, satisfactory was achieved and empirical formula was successfully established using the regression analysis method by deploying the height difference 'h' and penetration depth 'x' as the observed parameters.

• Journal of the Society of Naval Architects of Korea
• /
• v.56 no.3
• /
• pp.263-272
• /
• 2019

The aim of this study is to develop a rapid calculation technique of the residual strength in order to prevent sequential events under grounding accidents. Very Large Crude-Oil Carrier (VLCC), Suezmax, and Aframax double hull oil tankers carrying large quantities of crude oil were selected for target structures. The rock geometries are chosen from the published regulation by Marine Pollution Treaty (MARPOL) of the International Maritime Organization (IMO). Oceanic rocks as the most frequently encountered obstruction with ships are applied in this work. Damage condition was predicted using ALPS/HULL program based on grounding scenario with selected parameters, i.e. depth of penetration, damage location and tanker type. The results of the scenarios are quantified to form an empirical formula which can evaluate the residual strength. The proposed formula is validated by applying a series of random grounding scenarios.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2013.12a
• /
• pp.1-7
• /
• 2013

In past decades, a maximum standard vessel size for chemical tankers is not normally larger than 55,000 TDW due to the characteristic of chemical product shipment which is so variable but small quantity unlike single product carries such as crude oil tankers. These days, as demand of very large chemical tanker is rising due to the change of market trend of chemical product shipment, 75,000 TDW class chemical tanker has been developed. The newly developed vessel's structure has been designed based on CSR (Common Structural Rule) for double hull oil tankers (hereafter CSR) published by IACS (International Association of Classification Societies). However, due to the large difference from typical oil tankers, many items should be specially considered such as on deck transverse and corrugated bulkheads. In addition, two longitudinal bulkheads without upper stool have been constructed in order to maximise the number of cargo tanks and the volume of each cargo tanks. In this study, key word of the vessel has been briefly reviewed and the structural reliability of the proposed vessel has been investigated.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.5
• /
• pp.467-475
• /
• 2013

In order to seize quantitative materials as part of studies on measures for oil pollution prevention and control, the statistics of oil pollution incidents in Korean coastal waters for 10 years from 2003 to 2012 were analyzed with relation to the number of oil spills and the volume of oil spilt according to causes, sources and sea areas of spills. Total number and total volume of oil spills for 10 years were found to be 2,833 cases and 17,877 kL, respectively. 50.4 %(1,429 cases) of total number of oil spills were caused by negligence, although oil spillage due to negligence was 294 kL(1.7 %). While oil spillage caused by marine accidents was 17,400 kL(97.3 %), marine accidents accounted for 27.9 %(790 cases) of total number of oil spills. While negligence had a great influence on the number of oil spills, marine accidents had a huge impact on the amount of oil spilt. Fishing boats accounted for 42.7 %(1,210 cases) of the number of oil spills, and although oil tankers accounted for 9.2 %(261 cases) of the number of oil spills, oil spillage from oil tankers was 15,488kL(86.7 %). It means that oil tankers such as VLCC or ULCC may be the main sources of major oil spills and a few very large spills are responsible for a high percentage of the amount of oil spilt. While the number of oil spill incidents was closely related to the accidents of fishing boats, the volume of oil spilt was greatly affected by the major oil spill incidents of oil tankers such as M/T Hebei Spirit. The number and volume of oil spills were shown to be 1,613 cases(56.9 %) and 3,804 kL(21.3 %) in South Sea, 700 cases(24.7 %) and 13,501 kL(75.5 %) in West Sea, and 520 cases(18.2 %) and 572 kL(3.2 %) in East Sea of Korea, respectively. The highest number of oil spills was found in South Sea and the most volume of oil spilt was shown in West Sea of Korea for 10 years.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.7 no.2
• /
• pp.23-37
• /
• 2001

Marine environment has been polluted and damaged by many sources such as industrial waste, natural seepage, oil spill and offshore production etc. Among them, oil spill from oil tankers is one of most harmful sources to marine lives as its input amount is huge at a limited area for short period. In Korea, the port of Yeosu is known to be very vulnerable to oil spill with large amount of petroleum transported across the harbour. In this regards, the author analyzed and reviewed marine environment and appropriate response to marine oil spill at this area. For these purposes, oceanographic and meteorologic features as well as regional characteristics of harbor facilities, shipping routes, marine traffic and fisheries were investigated, also traffic densities were analyzed in order to check marine accident probabilities making direct observations for 72 hours visual1y and by portable radar.

• Journal of Digital Convergence
• /
• v.19 no.10
• /
• pp.195-202
• /
• 2021

The purpose of this study is to classify national ships into passenger ships, cargo ships, oil tankers, tugboats, barges, and other ships by use, and compare the rate of change and direction respectively. In this study, a total of 123 monthly data were searched from January 2011 to March 2021 in Statistics Korea's KOSIS "Traffic Logistics => Operating Vessel Statistics => Possesion State of National Vessels". To this end, we calculated the rate of change from the previous month for each ship and performed numerical analysis and model analysis. In the correlation analysis, the Total showed a high relationship in the order of Towing, Barge, Oil, Cargo and Ferry. In the regression analysis, each ship was found to be statistically significant and varied independently of each other. The increase rate was highest in the order of Ferry, Oil, Towing, Barge and Cargo during the last analysis period. In the analysis of Scatter Charts, Towing and Barge showed more than a certain level of synchronization with respect to the Total. The synchronization phenomenon for each ships was calculated to be rather low, indicating that the correlation between each ships was low. However, the correlation between Oil and Towing, Oil and Barge and Towing and Barge is relatively high, indicating a relatively large correlation.

• Journal of the Society of Naval Architects of Korea
• /
• v.47 no.4
• /
• pp.598-605
• /
• 2010

The structural design of oil tankers and bulk carriers should be performed based on the Common Structural Rules(CSR) which were recently established by the International Association Classification Societies(IACS). At first, in the structural design viewpoint, the scantling and hullweight based on the CSR should be compared with those of existing rules, and then a minimum weight/cost design should be performed by considering the variation of the number of web and the material property. In this study, the optimum web space and material property will be proposed by performing a minimum weight/cost design of a large oil tanker, and the results will be compared with those of existing ship. The longitudinal members are determined by SeaTrust-Holdan developed by the Korean Register of Shipping(KR), and the transverse members are determined by NASTRAN and PULS.

• Journal of Ocean Engineering and Technology
• /
• v.38 no.1
• /
• pp.1-9
• /
• 2024

The vertical center of gravity (VCG) has a significant impact on the roll motion response of a surface ship, particularly oil tankers based on the oil level in the tanker after discharging oil at several stations or positional changes, such as changes in the superstructure and deck structure. This study examined the motion response of the Korea very large crude carrier 2 (KVLCC2) at various VCGs, especially roll motion when the VCG changed. The potential theory in the Ansys AQWA program was used as a numerical simulation method to calculate the motion response. On the other hand, the calculations obtained through potential theory overestimated the roll amplitudes during resonance and lacked precision. Therefore, roll damping is a necessary parameter that accounts for the viscosity effect by performing an experimental roll decay. The roll decay test estimated the roll damping coefficients for various VCGs using Froude's method. The motion response of the ship in regular waves was evaluated for various VCGs using the estimated roll-damping coefficients. In addition, the reliability of the numerical simulation in motion response was verified with those of the experiment method reported elsewhere. The simulation results showed that the responses of the surge, sway, heave, pitch, and yaw motion were not affected by changing the VCG, but the natural frequency and magnitude of the peak value of the roll motion response varied with the VCG.

• Journal of Navigation and Port Research
• /
• v.26 no.4
• /
• pp.407-417
• /
• 2002

Japanese oil companies have begun to set up a mutual support system to prepare for any large scale oil spillages due to the huge increase in size of tankers since 1973. In 1990, the Petroleum Association of Japan established the Oil Spill Response Department and has been conducting researches on management of oil spill combatting materials and the effective prevention of maritime oil disasters. Japan Coast Guard, in accordance with the regulations of the OPRC in 1995, formulated the national contingency plan and built a mutual-contact network among the related government institutions. Its Guard & Rescue Department. Disaster Prevention Section has been working for the maintenance of oil spill combatting materials and coordinating related work with private organizations. The Japanese government has been strengthening the maritime oil spillage management system since the Nakhodka wreck incident in 1997.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.1
• /
• pp.88-96
• /
• 2021

When oil tankers, large passenger ships and cargo ships sink under the sea owing to various maritime accidents, the residual cargo oil or fuel oil in the such vessels could pose direct risk to factor for the marine environment and it require safe and rapid removal. Although domestic and foreign salvage companies are adopting various recovery methods and technologies with customizations according to each site during recovery operations studies on reasonable assessment modules for the operation process are relatively insufficient. In this study, the data from trapped-oil recovery operations performed at different site conditions were collected and analyzed in order to designed an operation assessment module, define the operational process steps in terms of preparation, implementation and completion, and derive key factors for each detailed process. Subsequently, the module was designed in such a way as to construct performance indicators to assess these key factors. In order to exclude subjective opinions from the assessment as much as possible, the assessment each item was constructed with indicators based on data that could be evaluated quantitatively and its usefulness was verified by applying the module to the trapped-oil recovery operation cases. We expect this the method and the technology assessment module for the trapped-oil recovery operation on sunken vessels will help to verify the adequacy of the trapped-oil recovery such operation before or after. Furthermore, it is expected that the continuous accumulation of assessment data and feedback from past or future operation cases will contribute toward enhancing the overall safety, efficiency and field applicability of trapped-oil recovery operation.