• Title/Summary/Keyword: Restricted waterways

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A study on the Manoeuvring Motion Under the Condition of External Forces in Restricted Waterways

  • Lee Chun Ki;Kang Il Kwon;Yoon Jeom Dong
    • Proceedings of KOSOMES biannual meeting
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    • 2003.11a
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    • pp.123-126
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    • 2003
  • In the present paper, the analysis is on the safe navigation between ships moving each other in restricted waterways under the external force, such as wind or current The numerical simulation of manoeuvring motion was carried out to propose an appropriate safe speed and distance between ships, which is required to avoid marine disasters from the viewpoint of marine safety. From the inspection q this investigation, it indicates the following result In case of proximal navigation between ships under the wind and current, the low-speed vessel is potentially hazardous because the rudder force if low-speed vessel needed for steady-state course-keeping is not sufficient, compared to the high-speed vessel The manoeuvring characteristic based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in restricted waterways.

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The assessment of Safe Navigation Regarding Hydrodynamic forces between ships in Restricted Waterways

  • Lee, Chun-Ki;Yun, Jong-Hwui;Yoon, Jeom-Dong
    • Proceedings of KOSOMES biannual meeting
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    • 2006.11a
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    • pp.143-149
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vesselsin restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transversedistance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the higher one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

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The Assessment of Safe Navigation Regarding Hydrodynamic forces between Ships in Restricted Waterways

  • Lee, Chun-Ki;Lee, Sam-Goo
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.2002-2009
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vessels in restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transverse distance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the bigger one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

The assessment of Safe Navigation Regarding Hydrodynamic forces between ships in Restricted Waterways

  • Lee, Chun-Ki;Yoon, Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.89-93
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    • 2006
  • This paper is primarily focused on the safe navigation between overtaking and overtaken vessels in restricted waterways under the external forces, such as wind and current. The maneuvering simulation between two ships was conducted to find an appropriate safe speed and distance, which is required to avoid collision. From the viewpoint of marine safety, a greater transverse distance between two ships is more needed for the smaller vessel. Regardless of external forces, the smaller vessel will get a greater effect of hydrodynamic forces than the bigger one. In the case of close navigation between ships under the forces of wind and current, the vessel moving at a lower speed is potentially hazardous because the rudder force of the lower speed vessel is not sufficient for steady-state course-keeping, compared to that of the higher speed vessel.

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The Interaction Effects Between Two Vessels in the Proximity of Bank Wall in Restricted Waterways (제한수역에서 측벽부근을 항해하는 두 선박간의 상호영향)

  • Lee Chun-Ki;Yoon Jeom一Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.49-55
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    • 2004
  • The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the water areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity if bank wall. The object if this paper is to propose a guideline of safe velocity if vessels and distance between them for navigating safely in confined sea areas.

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The Interaction Effects Between Two Vessels in the Proximity of Bank Wall in Restricted Waterways (제한수역에서 측벽부근을 항해하는 두 선박간의 상호영향)

  • Lee Chun- Ki
    • Journal of Navigation and Port Research
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    • v.29 no.1 s.97
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    • pp.17-22
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    • 2005
  • The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the waterway areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity of bank wall. The object of this paper is to propose a guideline of safe velocity of vessels and distance between them for navigating safely in confined sea areas.

Numerical study of hydrodynamic interaction on a vessel in restricted waterways

  • Lee, Chun-Ki
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.4 no.1
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    • pp.1-8
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    • 2012
  • The hydrodynamic interaction between ship and bank can't be neglected when a vessel is app- roached toward the tip of a wedge-shaped bank in restricted waterways, such as in a harbor, near some fixed obstacles, or in a narrow channel. In this paper, the characteristic features of the hydrodynamic interaction acting on a slowly moving vessel in the proximity of a wedge-shaped bank are described and illustrated, and the effects of water depth and the spacing between ship and wedge-shaped bank are summarized and discussed based on the slender body theory. From the theoretical results, it indicated that the hydrodynamic interactions decrease as wedge-shaped bank of angle ${\beta}$ in-creases. For water depth to draft ratio less than about 2.0, the hydrodynamic interactions between ship and bank in-crease sharply as h/d decreases, regardless of the wedge-shaped bank of angle ${\beta}$. Also, for lateral separation more than about 0.2L between ship and wedge-shaped bank, it can be concluded that the bank effects decrease largely as the separation increases.

A Study on the Safe Manoeuvring between Vessels under the Strong Current in Restricted Waterways (제한수역에서 강조류하에 근접항행중인 선박간의 안전조선(安全操船)에 관한 연구)

  • Lee, Chun-Ki;Yoon, Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.77-78
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    • 2007
  • The aim if the present research is to develop a guideline if a safe conducting distance according to separated distance and velocity if the two vessels to navigate safely in restricted waterways. The authors studied the hydrodynamic forces between two vessels running closely and calculated safe conducting distances according to separated distances and speeds if the vessels under the condition if wind and strong current.

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Assessment of Safe Navigation Including the Effect of Ship-Ship Interaction in Restricted Waterways (제한수역에서 두선박간의 상호간섭력을 포함한 안전항해의 평가)

  • Lee, Chun-Ki
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2003.05a
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    • pp.5-10
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    • 2003
  • This paper is mainly concerned with the assessment of safe navigation between ships moving each other in restricted waterways. The manoeuvring simulation was conducted parametrically to propose an appropriate sage speed and distance, which is required to avoid sea accident under the different conditions, such as ship-velocity ratios, ship-length ratios, separation and stagger between ships. The manoeuvring characteristics based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in confined water.

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Wave Field Near a Vessel in Restricted Waterway

  • Kim, Chang-Je
    • Journal of Navigation and Port Research
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    • v.35 no.7
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    • pp.557-562
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    • 2011
  • Shipwaves can have harmful effects on people who are using riverside and cause bank erosion, bank structures destruction in restricted waterways. The wave field near a vessel is consisted of a combination of a primary and secondary wave system in a shallow or restricted waterway. The water level depression(squat) and return current beside the hull are called the primary wave system. The secondary wave system, that is the wave height originates from a local disturbance point such as the bow of the ship. This study aims at investigating the characteristics of the wave field around a vessel in a restricted water in relation to navigation experimentally and theoretically. The return current and squat with a correction factor can be newly evaluated and the almost same high-sized wave heights take place on the whole waterway in a restricted water without regard to the distance from the sailing line.