• Proceedings of the KSME Conference
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• 2003.04a
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• pp.479-484
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• 2003

A non-contact 6D motion tracking system is proposed. The system consists of two color cameras, a color image grabber and a host computer, Motions of a floating vessel was measured by the constructed system. The instantaneous forces of the floating vessel are analyzed. The floating vessel was put on the water in a small water container in free conditions. The measured forces are reconstructed by the measurement results. The system can be used to non-contact measurements for 6D dynamic analysis of floating vessels.

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.2
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• pp.85-93
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• 2015

The nonlinear time-domain analysis method was implemented to carry out a series of integrated simulations for a deep-water crane vessel system composed of four sub components, including a floating vessel, lifted equipment, hoisting cable and dynamic positioning (hereinafter DP) system. The analysis of the coupled dynamics consists of the crane vessel and equipment connected using the crane wire, and the DP is modeled according to the wind, wave and current conditions. The DP systems were numerically implemented using a classical PD feedback controller, and various simulations of the deepwater installation were conducted using different conditions in order to evaluate the global performance of the floating crane vessel combined with the DP system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.5
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• pp.552-567
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• 2017

The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. The dynamic tension induced by the lifted object also affects the motion responses of the floating crane vessel in return. In this study, coupled motion responses of a floating crane vessel and a lifted subsea manifold during deep-water installation operations were investigated by both experiments and numerical calculations. A series of model tests for the deep-water lifting operation were performed at Ocean Engineering Basin of KRISO. For the model test, the vessel with a crane control system and a typical subsea manifold were examined. To validate the experimental results, a frequency-domain motion analysis method is applied. The coupled motion equations of the crane vessel and the lifted object are solved in the frequency domain with an additional linear stiffness matrix due to the hoisting wire. The hydrodynamic coefficients of the lifted object, which is a significant factor to affect the coupled dynamics, are estimated based on the perforation value of the structure and the CFD results. The discussions were made on three main points. First, the motion characteristics of the lifted object as well as the crane vessel were studied by comparing the calculation results. Second, the dynamic tension of the hoisting wire were evaluated under the various wave conditions. Final discussion was made on the effect of passive heave compensator on the motion and tension responses.

• Ocean and Polar Research
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• v.37 no.3
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• pp.235-247
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• 2015

The main purpose of procuring the oceanographic research vessel with state-of-the-art technology is to provide a floating laboratory to conduct field work on the global oceans. The vessel should be properly utilized to locate and evaluate unexplored natural resources as well as to contribute international efforts to better understand and manage global environmental issues. Top priorities in the vessel design are high safety standards, noise and vibration control efficiency, and effective application of research equipment. For the accomplishment of all activities, the vessel length over all should be extended ~100 m with a gross tonnage of ~5,900 ton. In particular, the dynamic positioning system II will essentially operate at sea state 6. The high efficiency emissions reduction system will also be adopted in preparation for entry into force of 3rd exhaust emission control (Tier III). About 130 navigational and scientific instruments will be installed. The final design and model test of the new research vessel were reviewed and completed, respectively, in 2014. Currently, the ship is being built on schedule and expected to be delivered in December 2015. Within the near future, the new vessel will assume the role of carrying out multidisciplinary oceanographic researches of the highest standards in a technologically advanced and environment friendly manner.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.3 no.1
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• pp.1-7
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• 2000

A new alternative for large deepwater field development is described. This "Oil Box" (aka "Box Spar") is a multifunction vessel capable of floating drilling, production, storage and offloading (FDPSO). It is distinguished from other Floating Production, Storage and Offloading (FPSO) vessels by its unique hull form and oil storage system. It's main advantages are flexibility derived from the floatover deck option, use of proven top tensioned riser technology, and motion characteristics which make it operable in a wide range of environmental conditions.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.43-46
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• 2011

The noise characteristics of multi-purpose dive support vessel show the different patterns such as types of noise sources, accommodation arrangement and etc due to its operation. Especially, the tunnel and retractable thruster for the dynamic positioning should be considered at the noise analysis. The floating floor is selected as the main measure of noise reduction and is constructed at the deck near the noise sources. In this paper, the noise analysis of dive support vessel is based on the estimation of noise sources and floating floor and SEA (Statistical Energy Analysis) is used for analysis of the air-born noise and structure-borne noise. The noise analysis of air conditioning system is also carried out and the noise results of cabin room are reviewed.

• Ocean Systems Engineering
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• v.3 no.2
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• pp.137-147
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• 2013

Moonpools are vertical wells in a floating body used onboard many types of vessels like cable-laying vessels and offshore support vessels. Moonpool gives passage to underwater activities for different types of ships as per their mission requirements. It is observed that inside a moonpool considerable relative motions may occur, depending on shape, depth of the moonpool and on the frequency range of the waves to which the ship is exposed. The vessel responses are entirely different in zero and non-zero Froude number. Former situation is paid attention in this study as the mission requirement of the platform is to be in the particular location for long period of operation. It is well known that there are two modes of responses depending on the shape of the moonpool viz., piston mode for square shape and sloshing mode for rectangular shapes with different aspect ratios of opening like 1:1.5 and 1:2 ratios. Circular shaped moonpool is also tested for measuring the responses. The vessel moored using heavy lines are modeled and tested in the wave basin. The moored lines are provided with pre-tension and the dynamic tensions on the lines are measured. The different modes of oscillations of water column are measured using wave gauge and the vessel response at a particular situation is determined. RAOs determined for various situations provide better insight to the designer. The experiments done in the wave basin may also be compared with a software package meant for handling moored floating bodies.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.1
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• pp.8-13
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• 2013

Excessive yaw motion of a turret moored vessel was examined in this paper. The vessel was moored by an internal turret and catenary mooring lines. The experiments were conducted in regular waves. Turret moored vessel can oscillate from side to side or move to one particular direction, and eventually exhibit large yaw motion. The results showed that the excessive yaw occured for specific condition, ratio of wave lengths and vessel length. It was found that turret moored floating vessel was unstable for regular wave period from 14 to 18 sec and excessive yaw occurred to maximum 50 deg. The time series, trajectory, phase plot and qualitative analysis are performed. The analysis showed that the results of experiments agreed with the that of analytic method and the excessive yaw could be predicted by the stability analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.369-377
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• 2014

In this paper, to recognize the collision behavior between a submerged floating tunnel(SFT) and underwater navigation vessel(UNV), both structures are modeled and analyzed. The SFT of collision point is modeled tubular section using concrete with steel lining. The other part of SFT is modeled elastic beam elements. Mooring lines are modeled as cable elements with tension. The under water navigation vessel is assumed 1800DT submarine and its total mass at collision is obtained with hydrodynamic added mass. The buoyancy force on SFT is included in initial condition using dynamic relaxation method. The buoyancy ratio (B/W) and the collision speed are considered as the collision conditions. As results, energy dissipation is concentrated on the SFT and that of the UNV is minor. Additionally, the collision behaviors are greatly affected by B/W and the tension of mooring lines. Especially, the collision forces are shown different tendency compare to vessel collision force of current design code.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.117-122
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• 2000

In these days, the pollution of marine environment near island at Korean coastal zone caused by the trash, human waste and livestocks excreta become series problem. One of the most economic and efficient way to prevent this pollution problem is to set up island circulating incineration system. In this paper, the results of feasibility study on the application of turtle boat hull form to the incinearting vessel has been summarized especially for the resistance and course keeping point of view.