• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.318-325
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• 2015

Korea has very strong shipbuilding industry in the world, so many new ships are constructed in Korean shipyards. These built vessels are carrying out sea trial at sea before delivering to shipowner, and sea trial ships cause navigation risk to other passing vessels to accomplish sea trial tests as quick turning, zigzag maneuvering and crash astern etc. in traffic congestion conditions. It occurred more than 1 collision accident related sea trial for recent 5 years. It has been increased about 30% of risk because of navigation of sea trial vessel by marine traffic flow simulation. This paper analyzed marine traffic density surveyed by AIS data for 7 days, and investigated position of marine accidents for 5 years in Korean coastal waterway, it established the sea trial prohibition areas as 10/100 level of total marine traffic volume, which is considered no danger for ship operator. This analyzed maritime safety law for setting of the prohibition waters to propose the basic legal system. It makes contribution to marine pollution prevention by setting of the sea trial prohibition water to improve the ship's navigation safety.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.71-78
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• 2007

Towing vessels have carried out the important role and service in the maritime industry construction, such as port and sea bridge construction, fairway dredging and sea reclamation etc. Furthermore, tugboat takes the largest portion in number of vessel at the domestic registry and barges as big as the general merchant vessel, which are getting specialized and larger, are in operation. In spite of the increase of marine accidents under this situation, there has been no proper measure for the safe navigation of tugboat in the aspect of a nation. This paper aims to propose the measure for the safe navigation of tugboat according to the frequent marine accident of tugboat with sea bridge. Therefore, we show an example of the sailing schedule and operation checklist based on the analysis of statistics and precedent of marine accident and the investigation of the actual operation state of tugboat in the aspect of a contract of carriage and a personnel setup, which should be checked by the operator of tugboat, to pass through sea bridge safely and propose the safe traffic supporting system based on electronic chart system to improve the safe navigation of tugboat.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.309-316
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• 2020

Waterway design should prioritize appropriate channel width to ensure preferential safe passage for the arrival and departure of vessels. To calculate the minimum channel width required for safe passage a comprehensive review of several factors is required. These factors include vessel maneuverability, determined by vessel size, type and speed; environmental factors such as wind, tide, and wave action; human factors, including personal experience and operator judgment as well as marine traffic and navigation support facilities for decision making. However, the Korean channel width design standard is based only on vessel length, and requires improvement when compared with the standards of PIANC, USA, and Japan. This study aims to estimate the appropriate channel width required for one-way traffic in a straight channel, considering various vessel and environmental factors, using Fast Time Simulation (FTS). When the wind speed is 25 knots, with a current speed of 2 knots and a normal vessel speed of 10 knots FTS shows that a 150K GT Cruise Ship requires a minimum channel width of 0.67-0.91 the vessel length (L), whereas a 120K TEU Container Ship and a 300K DWT VLCC require 0.79-1.17 and 1.02-1.59, respectively. Such results can be used to calculate the minimum channel width required for safe passage as an improved Korean design standard.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.101-108
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• 2007

Tugboat has carried out the important role and service in the maritime industry construction, such as port and sea bridge construction, fairway dredging and sea reclamation etc. Furthermore, tugboat takes the largest portion in number of vessel at the domestic registry and barges as big as the general merchant vessel, which are getting specialized and larger, are in operation. In spite of the increase of marine accident under this situation, there has been no proper measure for the safe navigation of tugboat in the aspect of a nation. This paper aims to propose the measure for the safe navigation of tugboat according to the frequent marine accident of tugboat with sea bridge. Therefore, we show a example of the sailing schedule and operation checklist based on the analysis of statistics and precedent of marine accident and the investigation of the actual operation state of tugboat in the aspect of a contract of carriage and a personnel setup, which should be checked by the operator of tugboat, pass through sea bridge safely and propose the safe traffic supporting system based on electronic chart system to improve the safe navigation of tugboat.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.1
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• pp.137-150
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• 1996

Safety is built in to the activities of the prudent ship operator. Ant investment made towards this end is likely to have a measurable payback in positive terms. That there must be an investment is inevitable, because the industry at large has let things slip too far too long. Those who have not allowed it to slip too far and who are the first to recognize that safety, far from costing money, in the long term actually preserves it, will be wieners. Too many seem to have lost sight of the fact that every one hundred pennies saved is a full one hundred pennies profit. Every hundred pennies of additional revenue contributes no more then fifteen pence to profit. Environmental protection is not so simple, nor so financially attractive. Man needs the minerals of the Earth as well as the products of the soil and sea survive. We(the human race) are still not in the position, politically or financially to manage the Earth's assets without causing damage. The evidence of our damage is evident in many different parts of the Glove and will in some cases haunt several generations still to come. We have learned a lot, and continue to learn, but despite the best intentions some Government needs for their people will be at the expense of people in another region for the foreseeable future. We sailors ply the seas with the raw materials of commerce as well as the finished and part finished goods. It does not always sit well to consider too deeply what effect the ship and the cargo it carries is having, or may have, on some communities, or on the sea through which sail. None my generation can hold up his head and claim to be without blame in the pollution of the seas. Times are changing though, and Governments are turning their attention more to the protection of our planet and its precious resources. This will not be without cost. The investment will have to be made not for our benefit, but for the benefit of generations yet to come, however the cost will have to be borne by society as a whole, not by the shipping community alone. The debate surrounding the choice between engineering our way to a better tomorrow, or adapting our working practices will continue. Each method has the same goal as its target and as long as we attain the goal does it really matter how we get there?

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.822-831
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• 2021

Although programs have been developed to evaluate the risk of dragging anchors, it is practically difficult for VTS(vessel traffic service) operators to calculate and evaluate these risks by obtaining input factors from anchored ships. Therefore, in this study, the gross tonnage (GT) that could be easily obtained from the ship by the VTS operators was set as an independent variable, and linear and nonlinear regression analyses were performed using the input factors as the dependent variables. From comparing the fit of the polynomial model (linear) and power series model (nonlinear), the power series model was evaluated to be more suitable for all input factors in the case of container ships and bulk carriers. However, in the case of tanker ships, the power supply model was suitable for the LBP(length between perpendiculars), width, and draft, and the polynomial model was evaluated to be more suitable for the front wind pressure area, weight of the anchor, equipment number, and height of the hawse pipe from the bottom of the ship. In addition, all other dependent variables, except for the front wind pressure area factor of the tanker ship, showed high degrees of fit with a coefficient of determination (R-squared value) of 0.7 or more. Therefore, among the input factors of the dragging anchor risk assessment program, all factors except the external force, seabed quality, water depth, and amount of anchor chain let out are automatically applied by the regression analysis model formula when only the GT of the ship is provided.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.256-265
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• 2021

Ground, sea and air mobility, such as vehicles, ships, and airplanes, are generally operated by people. Based on the innovative development of autonomous decision-making systems and artificial intelligence (AI) following the recent fourth industrial revolution, research and development on maritime autonomous surface ships (MASS) is been actively performed around the world. Before the realization of the commercialization of MASS in international maritime transport, it is urgent to clarify the characteristics of this ship and its international legal status. This paper aims to analyze the concern of whether a ship without crew members will eventually be operated as a fully unmanned ship or can be recognized as a ship under international law as the number of crew members is gradually reduced owing to the development stage of autonomous ships. Consequently, based on the United Nations Convention on the Law of the Sea (UNCLOS) and the regulations of the International Maritime Organization (IMO), it was found that MASS has the same international legal status as general ships. In addition this paper presents the working principles of enacting and revising the IMO Conventions and international legal measures necessary for the safe operation of MASS.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.395-402
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• 2019

The development and operation of the MASS (Maritime Autonomous Surface Ship) is being actively discussed for more efficient and safer maritime transportation solutions. The autonomous navigation technology has positive aspects such as the prevention of marine accidents, improvement of fuel efficiency of ships and cost reduction, and negative aspects such as job loss, task change, and security problems. It is expected that there will be new human element issues such as the situation awareness of remote operators, because the shore-based control will be conducted when fully autonomous ships are in operation. In this paper, we consider major human element issues that should be factored in the development and operation of MASS, and suggest a method of HRA (Human Reliability Analysis) for P IFs (Performance Influencing Factors) of the remote operators that are expected according to the shore-based control.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.452-459
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• 2015

It is important to use bench test results in the design process of anti-rolling tanks. Traditional bench tester is usually designed to perform only roll motions about a fixed axis and relatively small so that the viscous effects may not be neglected. Novel bench tester which could adjust the motion center to realize the coupled motion of sway and roll has been devised and manufactured therefore, large scaled bench tester could be utilized for designing the passive anti-rolling tanks. The time history of the reference signal from the rotation sensor of the bench tester have been recorded and processed to determine the phase angle to derive the Response Amplitude Operator(RAO) of the stabilized ship. The breadth of ART tank model should be large up to 2 m to diminish viscous scale effect and the vertical position of the tank can be varied with the ship's center of motion. The periods and the amplitude of roll motion can be varied from 1.5 sec to 5 sec and up to ±20°, respectively. The components of the tester was expressed in three dimensional digital mockup (DMU) and assembled together in the CAD space. The final configuration of the bench tester has been determined by confirming the smooth operation of the moving parts without interference through the animation in CAD space. New analytic logic are introduced for the determination of hydrodynamic moment and phase difference due to fluid motion in ART and verified through the test. The developed bench tester is believed to be effective and accurate for the verification of stabilization effect of ART taking into the consideration of the sway effect in the design stage.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.4
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• pp.260-271
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• 1993

Due to depletion of fish resources as time goes on, the trawl fishing industries which have caught the demersal fish is confronting with financial difficulties. For the purpose of breaking these difficulties, trawlers are expanding the fishing targets to the midwater from bottom stock. The trawlers become to be able to detect the fish schools not only vertical but also horizontal direction by equipping the sonar system on board. Even though the operator locates the fish school by sonar, it is not easy to make a desirable catch of the fish school which is detected, for the reason of the maneuverring characteristics of trawler. For the purpose of enhancing the efficiency of a fish catch, the auther performed a series of on board experiments to investigate the maneuverablilites of midwater trawaler. The obtained results are summerized as follows: 1. The higher the RPM of main engine, the smaller the magnitude of turning circle. And it is smaller in the right than in the left turning 2. Towing speed varies irregularly under turning novenment. When the RPM of main engine being 560, 680 the angular velocities are 11.3deg/min, 22.5deg/min respectively. 3. The difference of new course distance between calculated by maneuverring indices and measured by experimental ship is high when altering course being large and towing speed low. 4. The faster the towing speed is, the shorter the new course distance becomes. When towing speed is same in right and left turning movement, the now course distance is shorter in case of right turning movement than in left. 5. It is considered to be convenient for a navigator to utilize the curves for altering course in order to steer the ship rapidly and accurately.