• Bulletin of the Society of Naval Architects of Korea
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• v.24 no.4
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• pp.71-83
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• 1987

There is at present a growing interest in the use of SWATH(Small Waterplane Area Twin Hull )ship for a variety of purposes due to their good seakeeping characteristics, small speed reduction in wave, and large deck area. Highly sophisticated design technology is requested to develop the SWATH ship. This paper describes the design technology for high speed coastal passenger SWATH ship which includes feasibility study, general arrangement and hull form design, resistance and propulsion test, motion test in regular waves, control fin design, and structural design.

• Journal of the Korean Institute of Navigation
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• v.20 no.4
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• pp.1-6
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• 1996

A vessel in distress might be well identified when both the variables affecting the drifting of the vessel and the extent to which the variables affect the drifted vessel are known. And also the disembarking place inside the ship might be easily located if the drifting poised is forecasted. The forecasting method of the drifting poise is resolved by combining the vectors of the current and the wind. It is, however, very hard to forecast the effect of the wind, which should be mainly determined by field survey. This study aims at identifying the drifting characteristics of medium/large ships, considering only the effect of the wind. The experiment revealed the following results. $\circled1$ The drifting poise is determined by the aspect ratio of the ship and the shape of the superstructure of the ship. $\circled2$ Drifting direction is quite stable when wind speed goes over a certain level. $\circled3$ Drifting speed is 3-7% of the wind speed in case of T/S Hannara.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.33-34
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• 2012

We need to develop intelligent smart card made unskilled general public's to the shelter on Passenger Ship. prior to development, we have to study passenger of characteristic. so we researched about domestic unskilled general public's of walking speed in refuge situation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.3-10
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• 2006

Recently it is coming to be hish reality on visual system in ship-handling simulator depending on the technical development of 3D computer graphics. Even with high reality, it is possible that visual information presented seafarers through screen or display is not equivalent to the real world. In docking maneuvering, visual targets or obstructs are sighted close to ship's operator or within few hundred meters, so it might be possible to affect visual information such as the difference between both eyes' and single eye's visual sight. Because it is not possible to perceive of very slow ship's movement by visual in case of very large vessels, so the Doppler Docking SONAR and/or Docking Speed and Distance Measurement Equipment were developed and applied for safety docking maneuvering. By the way, the simulator training includes the ship's maneuvering training in docking, but in Ship-handling Simulator and also onboard, there are some limitations of perception of ship's movement with visual information. In this paper, perception of ship's movement with visual system in Ship-handling Simulator and competition of performances of visual systems that are conventional screen type with Fixed Eye-point system and Mission Simulator. We got some conclusions not only on the effectiveness for visual system but also on the human behavior in docking maneuver.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.318-323
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• 2014

When a disabled ship is being towed in a seaway, the speed and direction of the towed ship are estimated by using the towing force and direction of the selected tug boats at the predicted sea conditions including the wind and currents. In this paper, prediction method at the towing conditions of the various towing operations for a disabled ship are studied. The proposed calculation method suggests firstly the method to import the speed and resistance of the forward direction of the towed ship calculated by the existing computer program, second, the method to calculate the speed and resistance of the towed direction of the towed ship acquired from the selected tug boats at the initial towing conditions and lastly, the method to calculate the speed and resistance of the towed direction for the towed ship at the stable towing conditions. These calculation methods have been applied to the computer program and this program has been approved to be a useful program, capable of appropriately predicting the towed ship's conditions.

• Journal of Ocean Engineering and Technology
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• v.29 no.6
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• pp.418-426
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• 2015

Recently, shipping operators have been making efforts to reduce the fuel cost in various ways, such as trim optimization and bulb re-design. Furthermore, IMO restricts the hydro-dioxide emissions to the environment based on the EEDI (Energy Efficiency Design Index), EEOI (Energy Efficiency Operational Indicator), and SEEMP (Ship Energy Efficiency Management Plan). In particular, ship speed is one of the most important factors for calculating the EEDI, which is based on methods suggested by ITTC (International Towing Tank Conference) or ISO (International Standardization Organization). Many shipbuilding companies in Korea have carried out speed trials around the Korea Straits. However, the conditions for these speed trials have not been exactly the same as those for model tests. Therefore, a ship’s speed is corrected by measured environmental data such as the seawater temperature, density, wind, waves, swell, drift, and rudder angle to match the conditions of the model tests. In this study, fundamental research was performed to evaluate the ship resistance performance due to changes in the water temperature and salinity, comparing the ISO method and numerical simulation. A numerical simulation of a KCS (KRISO Container ship) with a free-surface was performed using the commercial software Star-CCM+ under three conditions that were assumed based on the water temperature and salinity data in the Korea Straits. In the simulation results, the resistance increased under low water temperature & high salinity conditions, and it decreased under high water temperature & low salinity conditions. In addition, the ISO method showed the same result as the simulation.

• Journal of the Korean Institute of Navigation
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• v.21 no.2
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• pp.11-17
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• 1997

In this paper, we studied to improve Inoue's[1] and Kijima's[2] model used to predict ship's manoeuvrability in initial design stage. To perform this work, we had PMM(Planar Motion Mechanism) test and rudder open water test for 12 Models of low-speed blunt-ship which have horn type rudder and bulb in afterbody. Using MMG(Mathematical Modelling Group) model, we analyzed hydrodynamic and MMG experimetnal coefficidnts used to search sensitivities and to estimate ship's manoeuvrability, adn the results are performed by the regression analysis of principle parameters. We varified them to analyze ship's manoeubbrability , had simulate manoeubrability to check revised MMG model and compared them wiht Inoue's method. the result of PMM test and sea trial. Then it is found that the revised method can predict the maneuverability more accurately even for an unstable ship.

• Journal of Navigation and Port Research
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• v.36 no.7
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• pp.571-575
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• 2012

Berthing and unberthing maneuver is essential work for marine pilots and securing the safety against risks during the maneuver is more important than anything else. Moreover, the maneuvering environment in ports and harbors has changed rapidly and got worse due to development of a new port, the advent of a new type or large-sized ship, and the rapid increase in harbor traffic. As one of measures taken to cope with such changes in the maneuvering environment and for each pilot to improve his own maneuvering ability, this paper developed laptop-based ship-handling simulator which is readily available anytime and anywhere. This paper is to develop a conning display for ship's maneuvering and electronic chart based display widely used nowadays to represent a model ship's movement. The displays were arranged appropriately considering pilot age, easy handling by mouse, using a maximum screen, proper arrangement of rudder, engine, thruster, tug etc and representation of information. Up to now thirteen (13) model ships were developed based on real-ship, whose mathematical model is Japanese MMG & pilots' low speed maneuver.

• Journal of Navigation and Port Research
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• v.33 no.8
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• pp.505-511
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• 2009

Vessels on anchoring are frequently dragged due to the increased area of wind pressure by enlargement of ship's size and sudden gust of winds in recent years. In the view point of the ship's navigators, the proper measurements corresponding to the dragging of anchor should be taken into account concerned about the time for the occurring of dragging by the external forces such as wind and wave, the pattern and speed of dragging and the possibility of collisions with any other vessels or obstacles. In this paper, it was examined the actual dragging anchor in T.S. HANBADA due to the wind and waves. From this case, it was found the critical external forces by which she was begun to dragged comparing the force by the wind, frictional resistance, drifting force and ship motion moment with the holding power. Also, through the analysis of the dragging pattern, it was known the alteration range of heading angle, swinging width and dragging speed etc.

• Journal of Navigation and Port Research
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• v.33 no.2
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• pp.99-104
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• 2009

The Kinematic GPS is well known to provide a quite good accuracy of positioning within an level. Although kinematic GPS assures high precision measurement on the basis of an appreciable distance between a reference station and an observational point, it has measurable distance restriction within 20 km from a reference station on land. Therefore, it is necessary to make out a simple and low-cost method to obtain accurate positioning information without distance restriction In this paper, the velocity integration method to get the precise velocity information of a ship is explained. The experimental results of Zig-zag maneuver and Williamson turn as the ship's maneuvering test, and other experimental results of ship's movement during leaving and entering the port with low speed were shown. From the experimental results, ship's course, speed and position are compared with those obtained by kinematic-GPS, velocity integration method and dead reckoning position using Gyro-compass and Doppler-log.