• Title/Summary/Keyword: Dead weight tonnage

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Dynamic Behavior of a Breasting Dolphin with Various Dolphin Heights and Slopes (돌핀의 높이와 경사에 따른 돌핀의 거동 특성)

  • Yoon, Gyeong-Seug;Cho, Won-Chul;Jo, Chul-Hee
    • Journal of Ocean Engineering and Technology
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    • v.23 no.6
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    • pp.44-52
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    • 2009
  • In this study, the behavior of a breasting dolphin with various dolphin heights and formations in the coastal area of Incheon was investigated. The dynamic deflection, shear stress, and moment of the pile were analyzed using the coefficient of the horizontal subgrade reaction that resulted from loading tests of different DWT (Dead Weight Tonnage). In the case of a vertical pile type dolphin, the deflection, shear stress, and moment increased as the dolphin height increased. In the case of the battered pile type dolphin, small values of shear stress and moment were shown at a low dolphin height, and the characteristics of the dynamic behavior of the dolphin showed that the deflection, shear stress, and moment increased as the pile slope of the dolphin decreased or the DWT increased.

Dynamic Behavior of the Breasting Dolphin Caused by Wave Power (파력에 의한 돌핀의 거동 특성)

  • Cho, Won Chul;Yoon, Gyeong Seug
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.281-287
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    • 2009
  • In this study, the behavior of breasting dolphin caused by the maximum wave height in the coastal area of Incheon has been investigated. The dynamic deflection, shear stress and moment of pile are analyzed using the coefficient of horizontal subgrade reaction resulted from loading tests for different DWT (Dead Weight Tonnage). The dynamic characteristics of pile in accumulated and dredged soils show almost the same pattern. It is shown that the resistance of dolphin to external load increases as the diameter of pile increases. The bettered pile dolphin is more than 10 times stable than the vertical pile type based on the study of dynamic characteristics of dolphin.

A bridge-vessel collision force of steel fender system (강재 충돌방호공의 선박충돌력산정)

  • Lee Gye Hee;Ko Jae Yong;Yu Won Jin
    • Proceedings of KOSOMES biannual meeting
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    • 2003.11a
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    • pp.127-133
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    • 2003
  • In this study, the impact analysis for the steel fender system that designed for protection of collision between vessel and bridge was performed The size of objective collision vessel assumed as 3000 dead weight tonnage(DWT). The impact forces and the impact energies were estimated by formulas of several design codes, and the steel fender system was designed based on the estimated forces and energy. The bow of objective vessel was modeled as rigid body, and bridge substructure was modeled as fixed support. Since, the impact analysis have the dynamic nonlinear features, such as, material nonlinear, large deformation and contact, explicit structural analysis program was used The analysis results presented that the impact forces formulas in codes have the sufficient conservativeness.

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A bridge-vessel collision analysis of steel fender system (강재 충돌방호공의 선박충돌해석)

  • 이계희;홍현석;백종균
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.71-78
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    • 2003
  • In this study, the impact analysis for the steel fender system that designed for protection of collision between vessel and bridge was peformed. The size of objective collision vessel assumed as 3000 dead weight tonnage(DWT). The impact forces and the impact energies were estimated by formulas of several design codes, and the steel fender system was designed based on the estimated forces and energy. The bow of objective vessel was modeled as rigid body, and bridge substructure was modeled as fixed support. Since, the impact analysis have the dynamic nonlinear features, such as, material nonlinear, large deformation and contact, explicit structural analysis program was used. The analysis results presented that the impact forces formulas in codes have the sufficient conservativeness.

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Maneuverability of a DWT 8,000-ton oil/chemical tanker by real sea trials - A comparison between the semi-balanced rudder and the flap rudder - (실선시험에 의한 DWT 8,000톤 선박의 조종성능 - Semi-balanced rudder and flap rudder -)

  • An, Young-Su;Lee, Hyeong-Geun;Park, Byung-Soo;Jang, Choong-Sik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.2
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    • pp.257-264
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    • 2015
  • This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test, Z" maneuvering test, man overboard rescue maneuver test, inertia stopping test. Consequently, $2^{st}$ Overshoot yaw angle of the semi balanced rudder and flap rudder in ${\pm}20^{\circ}$ zig-zag test showed $22.2^{\circ}$ and $18.0^{\circ}$, respectively. The maneuverability of the vessel was good in the flap rudder. The man overboard rescue maneuver maneuverability test was most favorable in the flap rudder and the full load condition. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.

A study on the turning ability of a DWT 8,000-ton oil/chemical tanker by real sea trials - A comparison between the semi-balanced rudder and the flap rudder - (실선시험에 의한 DWT 8,000톤 선박의 선회성능 - Semi-balanced rudder and flap rudder -)

  • Lee, Hyeong-Geun;An, Young-Su;Park, Byung-Soo;Jang, Choong-Sik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.2
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    • pp.245-256
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    • 2015
  • This study is intended to provide navigator with specific information necessary to assist the avoidance of collision and the operation of ships to evaluate the maneuverability of dead weight tonnage 8,000 tons Oil/Chemical tanker. The actual maneuvering characteristics of ship can be adequately judged from the results of typical ship trials. Author carried out sea trials based full scale for turning test in ballast condition and full load condition, semi balanced rudder and flap rudder. The turning circle maneuvering were performed on the starboard and port sides with $35^{\circ}$ rudder angle at the normal continuous rating. The results from tests could be compared directly with the standards of maneuverability of IMO and consequently the maneuvering qualities of the ship is full satisfied with its.

A study on the analysis of bearing reaction forces and hull deflections affecting shaft alignment using strain gauges for a 50,000 DWT oil/chemical tanker (스트레인 게이지를 이용한 5만 DWT급 석유화학제품운반선의 베어링 반력 및 선체변형량 분석에 관한 연구)

  • Lee, Jae-Ung
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.4
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    • pp.288-294
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    • 2016
  • In modern ships, the shafting system often becomes stiff owing to the high engine power, whereas the hull structure becomes more flexible owing to optimization using high-tensile-strength thick steel plates; therefore, more sophisticated shaft alignments are required. In this study, strain gauge-based measurement was conducted under five vessel operating conditions and bearing reaction forces and hull deflections affecting shaft alignment were analyzed for a 50,000 dead weight tonnage oil/chemical tanker that has gained repute as an eco-friendly vessel in recent years. Furthermore, the analytical results from each technique-theoretical calculation, jacking ups, and strain gauges-were cross-checked against each other in order to enhance the degree of accuracy and reliability of the calculation.

A Study on the Difference in Ballasting Time Arising from the Installation of an Ultraviolet Ballast Water Management System on Existing Ships (현존선에 자외선 평형수처리장치 설치로 인한 평형수 처리시간 변화에 관한 연구)

  • Seo, Kil-Cheon;Lee, Kyoung-Woo;Rho, Beom-Seok;Cho, Ik-Soon;Lee, Won-Ju;Pham, Van Chien;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.5
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    • pp.576-585
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    • 2020
  • This study quantitatively investigated the increase in ballasting time through numerical calculations when an ultraviolet (UV) ballast water management system (BWMS) is installed on an existing vessel. The calculation results indicate that the ballasting time of a gas carrier having 55,000 dead weight tonnage was 2.152 hours without installation of the UV BWMS and implementation of a flow control function. Ballasting time increased by 14.2% after installing the UV BWMS, and it increased by 20.4% with both its installation and implementation of a flow control function. If actual conditions are taken into account, ballasting time after installing the UV BWMS is estimated to increase by at least 30% compared with current ballasting time. Therefore, when concerned parties select a UV type BWMS, it is advisable for them to minimize ship operation losses from an increase in ballasting time by considering the capacity of the actual ballast pumps on board and the flow energy loss of the UV BWMS. Additionally, it is recommended that a BWMS with larger capacity, larger pipes, and pipes with inside coatings be used to minimize the increase in ballasting time after installation of the BWMS.