• Journal of the Society of Naval Architects of Korea
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• v.41 no.2
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• pp.98-105
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• 2004

This study focuses on an analytical approach to calculate four crane lifting forces for heavy ship hull blocks considering elongations of lilting slings. Four-crane-lifting is a redundant problem. During lifting procedures, in addition to the force and moment equilibrium equations, a compatibility condition is introduced to determine 4 unknown lifting forces. For verification of the method, a ship hull block with field measurements data is analyzed and the result shows that the information obtained by current method could be useful to engineers to conduct lifting work at shipyards.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.147-147
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• 2018

• Journal of Ocean Engineering and Technology
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• v.14 no.1
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• pp.17-22
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• 2000

This study focuses on a simple analytical approach to calculate crane lifting forces for a sunken ship. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the vessel including the effect of lug positions. The importance of the sunken ship salvage is explained from the statistics of ship casualties during last 15 years. Euler angles are introduced to represent the inclination of a sunken ship in developing the static force and moment equations,. Three dimensional examples with one redundant degree of freedom for a GT1500 oil tanker are analyzed and the results show that the information obtained by the method could be useful to salvors to conduct salvage work.

• Journal of Ocean Engineering and Technology
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• v.17 no.3 s.52
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• pp.33-38
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• 2003

This study focuses on an analytical approach to calculate crane-lifting forces for a sunken ship, with consideration to elongation of crane ropes. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the ship's hull, including the effect of lug positions. For lifting analysis, the Euler angles are defined to represent the inclination of a sunken ship in developing the static force and moment equations. An additional compatibility condition is introduced in order to solve an indeterminate lifting analysis problem with 4 cranes. A set of lifting forces along the 4 crane ropes is calculated. A 3-dimensional example of the G/T 1500 oil tanker is analyzed. The results show that the information obtained by the method could be useful to engineers when conducting salvage work.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.255-255
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• 2017

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.179-184
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• 2003

This study focuses on an analytical approach to calculate crane lifting forces for a sunken ship in consideration oj elongation of crane ropes. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the ship's hull including the effect of lug positions. For lifting analysis, the Euler angles are defined to represent the inclination of a sunken ship in developing the static force and moment equations. An additional compatability condition is introduced in order to solve an indeterminate lifting analysis problem with 4 cranes and a set of lifting forces along the 4 crane ropes is calculated. A 3-dimensional example of the G/T 1500 oil tanker is analyzed and the results show that the information obtained by the method could be useful to engineers to conduct salvage work.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.387-394
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• 2015

Before salvaging a wrecked ship, the physics-based simulation is needed to predict lifting force before real operation by floating crane or barge. Procedures affecting lifting force for the salvage can be divided into three stages. At the first stage, the bottom breakout force for the wrecked ship to escape from seabed sediment should be calculated. At the second step, the current force acting on the wrecked ship while lifting from the seabed to near sea surface should be considered. Finally, buoyancy change near at the sea surface when the wrecked ship start to escape from the water should be considered. In the previous studies, only the breakout force at the first stage was calculated based on simple assumption of embedment depth and contact area of the wrecked ship. Therefore, we develop a program for salvage simulation including whole stages. It is composed of four modules such as the equations of motion, time integration, force calculation, and visualization. As a result, it is applied to simulate lifting the wrecked ship according to various environmental loads including seabed sediments.

• Journal of Conservation Science
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• v.33 no.1
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• pp.35-42
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• 2017

The Yeongheungdo shipwreck was excavated in the sea of Seomeopbeol, Ongjin-gun, Incheon, Korea. Chemical characterization of timbers from the shipwreck occurred via maximum moisture content, chemical composition, FT-IR, solid state $^{13}C$ NMR, and XRD analyses. As maximum moisture content of the outer part of the timbers averaged 623%, a phenomenon in that lignin increased relatively, according to the decrease in cellulose, and the ash content increased, which is typical of waterlogged archaeological wood was shown. The results from the FT-IR and solid state $^{13}C$ NMR analyses showed that the cellulose band of the outer part had disappeared or had remarkably decreased. In addition, the bands assigned to lignin dramatically increased. However, regarding the inner part of the timbers, hemicellulose and some crystalline cellulose and amorphous cellulose bands decreased. Therefore, a large difference exists between the degradation levels of the outer and inner parts of the timbers of the Yeongheungdo shipwreck.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.77-82
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• 2007

선박의 해난에 의한 해양오염사고 발생시, 해양경찰은 민관 방제세력의 동원 및 방제조치, 방제지원시스템을 운용 등을 통하여 신속하고 체계적인 방제전략을 수립 시행함으로써, 사고로 인한 해양환경 피해를 최소화하고 있다. 본 연구에서는 2006년 7월 전북 군산시 새만금방조제 인근 해상에서 침몰한 700톤급 준설선 GA-P1 호에 대한 선체인양 및 해양오염사고 처리 과정에서 방제지원시스템을 이용한 대응 사례이다.

• Journal of Ocean Engineering and Technology
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• v.16 no.1
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• pp.71-75
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• 2002

대형 시추구조물의 건조는 보통 드라이도크에서 하거나, 해양에서 선체와 데크를 접합하는 방법을 사용한다. 그러나 적당한 해양 접합장소가 없거나 드라이도크의 공간부족으로 현대중공업에서는 드라이도크나 해양에서의 접합건조 대신 부유식 시추구조물을 지상에서 조립하는 방법을 채택하게 되었다. 현대중공업에서는 세 가지 단계를 통해 지상 데크조립을 수행하였다. 첫 번째는 네 개의 철골구조 리프팅타워 상에서 유압리프팅시스템을 이용하여 데크를 지상으로부터 38m 들어올린다. 두 번째는 마찰을 줄이기 위해 윤활제가 칠해진 합성 플라스틱으로 싸인 미끄럼틀(Skidway)을 이용하여 두 개의 6000톤 짜리 하부구조를 데크 아래로 끌어 들인다. 마지막 단계로 데크와 하부구조를 단단히 결합시킨다. 이 과정에 2주일이 소요되었으며 일련의 작업을 거쳐 중량 25,500톤급의 Deepwater Nautilus (RBS-8M) 시추선을 무사히 바다 위로 인도하였다. RBS-8M의 데크결합에 Super Lift를 적용하여 성공시킨 사례를 통해 현대중공업의 초대형 시추구조물 건조방식이 이상적이고, 작업 공기나 원가 측면에서 우위가 있음을 시사하고 있으며 이렇게 건조작업의 대부분을 지상에서 수행한 과정을 통해 작업관리, 품질관리, 일정관리에도 좋은 결과를 가져올 수 있었다.