• Korean Journal of Computational Design and Engineering
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• v.15 no.1
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• pp.70-83
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• 2010

Recently, floating cranes are mainly used to erect heavy blocks or cargos for constructing ships in many shipyards. It is important to estimate the dynamic motion of the heavy cargo suspended by a floating crane and the tension of the wire ropes between the floating crane and the heavy cargo. In this paper, the coupled dynamic equations of motion are set up for considering the 6 degree-of-freedom floating crane and the 6-degrees-of-freedom heavy cargo based on multibody system dynamics. Depending on the cargo weight, the motion of the floating crane would be changed to nonlinear state. The nonlinear terms in the equation of motion are considered. In addition, the nonlinear hydrostatic force, the linear hydrodynamic force, wire rope force, mooring force and gravity force are considered as the external forces. As the result of this paper, we analyze the engineering effect for erecting the heavy cargo by using the floating crane.

• Journal of Korea Port Economic Association
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• v.33 no.3
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• pp.35-52
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• 2017

Interest and demand in heavy cargo logistics is increasing and becoming more diverse as economic scales have expanded and manufacturing activity has increased. Although cargo moves via maritime and/or land transportation, there is currently insufficient research on the actual condition of heavy cargo logistics. The purpose of this study is to carry out an in-depth analysis of heavy cargo laws, systems, logistics patterns, and current transportation status. By proposing measures to solve existing problems, this study aims to make an important and ongoing contribution to the scarcely studied field of heavy cargo logistics. The result of regression analysis on the main seven factors show that transportation frequency and law/system structure have a positive effect on working conditions. Furthermore, the result of correlation analysis on the main seven factors show that the cargo weight variable is highly positively correlated with cargo size. Also, the working conditions variable is highly positively correlated with the law/system structure. Detailed proposal measures to solve existing problems are summarized as follows. First, it is necessary to establish a clear concept of heavy cargo as numerous existing definitions differ. Second, laws and provisions relating to maritime and land transportation of heavy cargo need to be established and consolidated as current applicable legislation is insufficient. Third, the classification system for heavy cargo transportation needs improvement. Fourth, it is necessary to improve transportation performance statistics and the aggregate criteria system. Finally, the management system of heavy cargo also needs improvement.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.95-100
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• 2011

In general, thickness of bottom floor in fore/aft cargo hold region for container ship has been determined based on FEM analysis result of mid cargo hold region. But this approach has room for improvement because section shape and frame spacing in fore/aft cargo hold of container ship are quietly different from those of mid cargo hold. From this study, correlation between FEM result and grillage analysis result has been investigated and simple method for thickness determination of bottom floor in fore/aft cargo hold using newly improved grillage analysis is proposed.

• Journal of the Korean Institute of Navigation
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• v.20 no.2
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• pp.15-32
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• 1996

The Internation Maritime Organization (IMO) has required that ships other than cellular-ships which carry cargo units and other entities should be provided with a cargo securing manual. A number of serious accidents has resulted from improper stowage and insufficient securing of heavy cargo. The cargo claims caused by the accidents stated above not only reduce the number of shippers but also reduce their benefits. The following four basic safe items should be considered carefully in the carriage by sea in case of two tiers loading of heavy cargoes packed with wooden case if it is a general cargo ship. a) Safe stowing place b) Safe lashing c) Protecting crushing goods d) Adequate dunnage. All operators of cargoes must be reminded that only the proper stowge and securing of heavy cargos can prevent from the occurrence of such accidents in the future. This paper intends to analyze the unigue damage mechanism for two tiers loading of heavy cargoes on the general cargo ships encountered in the rough sea, and suggest the countermeusere to prevent the identical accidents in the future.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.160-172
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• 2023

In contemporary global warfare, the significance and imperative of air transportation have been steadily growing. The Republic of Korea Air Force currently operates only light and medium-sized military cargo planes, but does not have a heavy one. The current air transportation capability is limited to meet various present and future air transport needs due to lack of performance such as payload, range, cruise speed and altitude. The problem of population cliffs and lack of airplane parking space must also be addressed. These problems can be solved through the introduction of heavy cargo planes. Until now, most studies on the need of heavy cargo plane and increasing air transport capability have focused on the necessity. Some of them suggested specific quantity and model but have not provided scientific evidence. In this study, the appropriate ratio of heavy cargo plane suitable for the Korea's national power was calculated using principal component analysis and cluster analysis. In addition, an optimization model was established to maximize air transport capability considering realistic constraints. Finally we analyze the results of optimization model and compare two alternatives for force structure.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.52-58
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• 2009

Openings for access to cargo holds are cut on horizontal stringers in every bulkhead of container carriers. But, they are positioned at the edge of stringer width to make minimum space for access and these openings are required to be stiffened by owners and classifications respectively. In this paper, the cargo hold bulkhead stringers with openings for 6,500 TUE container carriers were reviewed by FE analysis to be conducted with the results of hold analysis for 6,500 TUE container carriers classed to GL, DNV, LR and BV respectively, and purpose of this paper is to establish yard's standard of the reinforcement for these openings.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.75-83
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• 2011

This research explores the relative importance of factors and service items that influence the air cargo service quality for provision services by the Skyteam Cargo in the Korean market. In general, the Skyteam Cargo provides a package of services which are different functions and operations of service such item as Equation Heavy (heavy and large express freight), Equation (small express freight), Variation (special freight), and Dimension (general freight). To carry out the research, the expert questionnaire survey, the Analytic Hierarchy Process (AHP) analysis had adopted to evaluate the level of quality for the provision air cargo operation services by the Skyteam Cargo at Incheon International Airport. Based on an expert survey and the AHP, five core service factors, namely, infrastructure as installed facilities, reliability, promptness, efficiency, and safety are defined.

• Journal of Ship and Ocean Technology
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• v.12 no.1
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• pp.35-44
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• 2008

As arctic energy resource is attracting public attention, arctic shipping market will also be growing in large as expected to increase in LNG trade from Arctic area to the western countries by shipping. During the voyages through such routes, collision with icebergs may be possible. In the present report, ice collision analyses are carried out from a practical point of view to verify the safety of hull structural strength of LNG carriers equipped with GTT $MKIII^{TM}$ membrane type cargo containment system. From the results of collision analyses and the operation-friendly design concept of no-repairing of cargo containment system, a safe operating envelope against ice collision is proposed for LNG carriers of membrane type cargo containment system. Based on the currently proposed safety criteria, it is concluded that LNG carriers with membrane tank type can operate safely with regard to the integrity of CCS in regions where collision between LNG carrier and iceberg is expected.

• 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 Ship and Ocean Technology
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• v.5 no.3
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• pp.36-44
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• 2001

The collision energy absorbing characteristics of side structure of the LNG carriers which have the cargo containment systems of the spherical and the membrane types are compared. A failure mechanism of the double hull side structures of 130, 000 $m^3$ class LNG carriers under sideways collision event has been simulated by using the detailed finite element calculations. In ship collision analysis, the finite element method based on explicit time integration has been use[1 with much success. Finite element modeling techniques for detail description of structural members antral ship motion regarding the dynamic behavior allowed to investigate the effect of bow shape and the initial contact position on side shell of collided ship. In the numerical simulations of the ship-to-ship sideways collision, the effect of the colliding bow shapes and the change of the colliding ship draft are investigated. The critical collision energy which is absorbed by a side structure of a collided ship until the fore-end of colliding ship arrives at the boundary of the cargo tank is calculated. The critical speed of specified colliding ships which can not penetrate the boundary of the LNG cargo tank of the collided ship under collision accident if evaluated.