• Title/Summary/Keyword: Oscillation quantity of moored ship

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Evaluation of Effective Working Days in a Harbor Considering Harbor Resonance and Moored Ship Motion (항만공진주기와 선박동요량을 고려한 항만가동율 산정)

  • Kwak, Moonsu;Moon, Yongho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.1
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    • pp.14-24
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    • 2015
  • This study proposed an estimation method of allowable wave height for loading and unloading of the ship and evaluation of effective working days considering moored ship motion that is affected by sip sizes, mooring conditions, wave periods and directions. The method was examined validity by comparison with wave field data at pier $8^{th}$ in Pohang New Harbor. The wave field data obtained with wave height of 0.10~0.75 m and wave period of 7~13 s in ship sizes of 800~35,000 ton when a downtimes have occurred. On the other hand, the results of allowable wave height for loading and unloading of the ship in this method have obtained with wave heights of 0.19~0.50 m and wave periods of 8~12 s for ship sizes of 5,000, 10,000 and 30,000 ton. Thus this method well reproduced the field data respond to various a ship sizes and wave periods. And the results of this in Korea are didn't respond to various the ship sizes and wave periods, and we h method tended to decrease in 16~62 percent when have considered long wave, and it is decreased in 0~46 percent when didn't consider long wave than design standards in case of the ship sizes of 5,000~30,000 ton, wave period of 12 s and wave angle of $75^{\circ}$. The allowable wave heights for loading and unloading of the ship proposed by design standards in Korea have found that overestimated on smaller than 10,000 ton. On the other hand, the rate of effective working days considering ship motion at pier $8^{th}$ in Pohang New Harbor reduced in 6.5 percent when compare with the results without considering ship motion.

A Study on Estimation of Allowable Wave Height for Loading and Unloading of the Ship Considering Ship Motion (계류선박의 동요량을 고려한 하역한계파고 산정 방법에 관한 연구)

  • Kwak, Moon Su;Moon, Yong Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.3
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    • pp.873-883
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    • 2014
  • This study proposed an estimation method of allowable wave height for loading and unloading of the ship considering ship motion that is affected by ship sizes, mooring conditions, wave periods and directions. The method was examined validity by comparison with wave field data at pier $8^{th}$ in Pohang new harbor. The wave field data obtained with wave height of 0.10~0.75m and wave period of 7~13s in ship sizes of 800~35,000ton when a downtimes have occurred. On the other hand, the results of allowable wave height for loading and unloading of the ship in this method have obtained with wave heights of 0.19~0.50m and wave periods of 8~12s for ship sizes of 5,000, 10,000 and 30,000ton. Thus this method well reproduced the field data respond to various a ship sizes and wave periods. And the results of this method tended to decrease in 16~62% when have considered long wave, and it is decreased in 0~46% when didn't consider long wave than design standards in case of the ship sizes of 5,000~30,000ton, wave period of 12s and wave angle of $75^{\circ}C$. The allowable wave heights for loading and unloading of the ship proposed by design standards are didn't respond to various the ship sizes and wave periods, and we have found that the design standards has overestimated on smaller than 10,000ton.

A Study to Improve the Operation Criteria by Size of Ship in Ulsan Tank Terminal (울산항 위험물 취급부두의 선박크기별 운용기준 개선방안에 관한 연구)

  • Kim, Seungyeon;Kim, Jongsung;Kim, Youngdu;Lee, Yunsok
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.6
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    • pp.639-646
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    • 2016
  • In order to establish an operational standard based on ship size, this study considered a specific safety management plan for Ulsan along with international standards, analyzed the results of mooring safety assessment at four vulnerable piers and suggests cargo stoppage and emergency unberthing standards as follows. In accordance with ship characteristics, ships of less than 10,000 tons are recommended to limit their activities for wind speeds of 18-21 m/s and wave heights of 1.0-1.5 m. Ships from 10,000-50,000 tons are recommended to observe wind speeds of 17-20 m/s and wave heights of 1.2-1.5 m, while, ships of 50,000-100,000 tons are recommended wind speeds of 15-19 m/s and wave heights of 1.5 m. Ships of more than 100,000 tons are recommended wind speeds of 14-18 m/s and wave heights of 1.5 m.