• Journal of Ocean Engineering and Technology
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• v.13 no.1 s.31
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• pp.18-22
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• 1999

One of the problem areas in designing a barge is its resistance and corese stability when it is towed by a tugboat. In this paper, as a part of design of a incinerating vessel, the results of some experimental studies on the effect of various kinds of anti-yawing skegs to the course keeping stability and on the additional resistance caused by them were summarized.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.351-356
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• 1999

An elasto-plastic constitutive model was Proposed, in which the behavior at small-to-large strain level can be modeled. From a mathematical approach it was proved that the model includes the previous successful models. The experimental results of a series of resonant column tests, torsional shear tests and triaxial tests were verified and as a result the proposed model could predict small-to-large strain behavior more consistently and accurately than the hyperbolic model and the Ramberg-Osgood model for a weathered granitic soil.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.291-305
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• 2010

A three-dimensional time-domain calculation method is of crucial importance in prediction of the motions and wave loads of a ship advancing in a severe irregular sea. The exact solution of the free surface wave-ship interaction problem is very complicated because of the essentially nonlinear boundary conditions. In this paper, an approximate body nonlinear approach based on the three-dimensional time-domain forward-speed free-surface Green function has been presented. The Froude-Krylov force and the hydrostatic restoring force are calculated over the instantaneous wetted surface of the ship while the forces due to the radiation and scattering potentials over the mean wetted surface. The time-domain radiation and scattering potentials have been obtained from a time invariant kernel of integral equations for the potentials which are discretized according to the second-order boundary element method (Hong and Hong 2008). The diffraction impulse-response functions of the Wigley seakeeping model advancing in transient head waves at various Froude numbers have been presented. A simulation of coupled heave-pitch motion of a long rectangular barge advancing in regular head waves of large amplitude has been carried out. Comparisons between the linear and the approximate body nonlinear numerical results of motions and wave loads of the barge at a nonzero Froude number have been made.

• Journal of Environmental Impact Assessment
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• v.9 no.2
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• pp.127-142
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• 2000

This research was performed for analyzing the transport of suspended solids during the harbor construction. In behalf of the research, we have analyzes the characteristics of suspended solids movement in sand reclamation of breakwater according to age of tide and tidal period at the construction spot of Pusan new harbor. In the process of sand reclamation, soil was dumped by a dumping device which direct soil from the barge to the bottom of the sea. According to the results from this research, suspended solid concentration was very high in the range of 5m from the dumping point right after the dumping. However these suspended solids settled very quickly and the solids concentration was very beyond 10m from the dumping point. It is deduced that the movement of solids dumped from barge has the tendencies as following; 1) Most of the dumped solids precipitated quickly after the dumping 2) The rest of the suspended solids are diffused slowly toward the bottom of the water being figured smoothing curve 3) The diffusion movement of suspended solids tend to proceed toward the shore line in a parallel motion with tidal current at the sea-bottom That is to say, most of the suspended solids precipitated very quickly even though highly concentrated solids produced at the bottom of the solids which did not precipitated spread with the tidal current horizontally along the bottom of the sea.

• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.274-280
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• 2017

Generally, global performance analysis in offshore platforms is performed using potential-based numerical tools, which neglect hydrodynamic viscous effects. In comparison with the potential theory, computational fluid dynamics (CFD) methods can take into account the viscous effects by solving the Navier-Stokes equation using the finite-volume method. The open-source field operation and manipulation (OpenFOAM) C++ libraries are employed for a finite volume method (FVM) numerical analysis. In this study, in order to apply CFD to the global performance analysis of a hull-mooring coupled system, we developed a numerical wave basin to analyze the global performance problem of a floating body with a catenary mooring system under regular wave conditions. The mooring system was modeled using a catenary equation and solved in a quasi-static condition, which excluded the dynamics of the mooring lines such as the inertia and drag effects. To demonstrate the capability of the numerical basin, the global performance of a barge with four mooring lines was simulated under regular wave conditions. The simulation results were compared to the analysis results from a commercial mooring analysis program, Orcaflex. The comparison included the motion of the barge, catenary shape, and tension in the mooring lines. The study found good agreement between the results from the developed CFD-based numerical calculation and commercial software.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.681-689
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• 2012

In this study, we performed a simulation of the dynamic response of a multibody system to calculate the tension acting on wire ropes connecting floating cranes and a heavy cargo such as a Giga Block weighing over 5000 tons when the cargo is salvaged using parallel connected floating cranes. In this simulation, we supposed that the motion of the floating cranes, barge ship, and heavy cargo has 6 degrees of freedom and that the interaction is determined by constraints among them. In addition, we considered independent hydrostatic and hydrodynamic forces as external forces acting on the floating cranes and barge ship. The simulation result can be a basis for verifying the safety of construction methods in which heavy cargo is salvaged by parallel connected floating cranes, and it can also be used to guide the development of such construction methods.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.6
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• pp.595-602
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• 2009

Great number of ships has been built by Korean Shipyards since early of 2,000 due to the expanding worldwide trade. Most of shipyards have enlarged the weight of erection block and many blocks have been assembled in block fabrication factories outside the shipyards to reduce the shipbuilding period. Especially, Giga blocks that exceed 2,000 tons are often assembled by the block fabrication factories outside the shipyard. Generally, the blocks are transported to building dock in shipyard by towing barges. Accident can be occurred during the sea transportation and it may bring about not only the delay of delivery but also a disaster on the ocean environments. Transportation condition of GPE (Grand Pre-Erection) block differs from the ocean going conditions of marine vessels. Special consideration should be included before transportation work in order to guarantee the safety of GPE blocks and barge carriers. In this paper, several examples, which have been investigated to set up the safety standard of transportation of the GPE blocks on coastal routes, are introduced. For the barge transportation on coastal sea route, the design criteria are discussed, considering the design wave, the acceleration induced by wave, structural strength, and the fixture condition of blocks.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.343-352
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• 2018

In this study, a motion control problem for the vessels towed by tugboats or towing ships on the sea is considered. The towed vessel looks like the barge ship, which is used for many purposes. In these vessels, basically, the power propulsion system is not installed but just towed by a towing vessel such as tugboats with ropes and wires. It means that the motions of towed vessel are basically dependent on the tracking route of towing boat. Therefore, in some cases, undesirable and unpredictable motions may be made by environmental factors such as wave, wind attack and so on. As a result, a collision accident with others may occur during maneuvering situation. Based on these facts, the authors try to encourage the steering performance of the towed vessel by using controllable rudders without any propulsion system. In this study, especially, a controllable vessel with three rudders is considered, and a mathematical model is induced for the future study. The model is described as surge, sway motion and inertia moment by following the general representation method for the surface ship.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.768-773
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• 2009

Measuring method being applied for off-shore works is performed by using data logger or manual measuring instrument with wiring the cable connected from the sensor up to the position where measuring is allowed.(upper part of embankment or marine structure) Measuring management by using existing measuring method may be acceptable on the condition that the ground deformation volume(vertical, horizontal) is generally minimal and the site condition is good. But loss of measuring instrument, sensor cable failure or cutting is taken place frequently due to significant change of ground behavior caused by an external force change(embankment, excavation) under very soft ground condition(N value below 0-4). In case of the marine works, in particular, loss rate of measuring instrument is highly represented due to the factors of working barge anchoring, constructional interference and natural disaster. In order to solve these problems, measuring management was performed with employing underground wireless system at the immersed tunnel site. Measuring data was obtained freely under the marine environment by using underground wireless communication and cable cutting potential by ground behavior could be reduced. Measuring cost savings and its installation convenience were maximized by way of off-shore tower installation or cabling and by minimizing constructional interference of off-shore working barge. This case of measuring management was accomplished successfully.

• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.303-308
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• 2009

Recently, unmanned systems have been studied and developed in various areas including aircrafts, automobiles and vessels. In addition, many researches about unmanned systems in Korea have been studying actively with the advancement of IT However, it is not satisfied with the result of the researches and developments. Bemuse of the reason we've here tried to make a very small USV which is a barge type. We applied the Great circle navigation calculation based on GPS to the autonomous navigation algorithm and used the LabVIEW 8.2 developed by NI corp. for programming The engine and rudder were controlled by pulse width modulation method. The engine system was composed of the DC motor and ESC(Electronic Speed Controller). It was also applied by the direct cooling system using DC motor pump. A very small USV was designed and made by ourself and it was verified the effectiveness of autonomous navigation algorithm through the tests at the sea.