대한조선학회 특별논문집 (Special Issue of the Society of Naval Architects of Korea) (Special Issue of the Society of Naval Architects of Korea)
대한조선학회 (The Society of Naval Architects of Korea)
- 2년1회간
과학기술표준분류
- 기계 > 조선/해양시스템
대한조선학회 2009년도 특별논문집
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Recent growth in global economic situation has led dramatic increase in new buildings of large containerships. These increased new building orders have brought keen concerns of developing and improving the quality of design and increasing the productivity of the vessel in order to satisfy the ship Owner's various requirements. For the increment of productivity and quality of containership, the plastic type bearing pad of cargo hatch cover has been investigated intensively for years with the supplier of cargo hatch cover. The result of investigation showed that there are numbers of advantages for the Owner and Builder over the existing bronze bearing pads which are better corrosion resistance long life time, low friction coefficient, easy maintenance, easy installation, better production lead time and low maintenance cost.
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The present paper addresses development of a GTT NO96 membrane type 170K m3 LNG carrier targeted to operate in moderate ice infested seas including Baltic Sea, Sakhalin port of Sea of Okhotsk, Murmansk port of Barents Sea, etc. Critical design issues are covered in detail to meet the requirements coming from the missioned operation conditions comprising low design ambient temperature, harsh wave conditions, stringent environmental protection policies, etc.
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After the installation of electric cables at block, PE(pre-erection) and hull stages, the coating stains on the electric cable sheath were unavoidably occurred by additional painting process. According to class rules paint or coating applied on the electric cables shall not adversely affect the mechanical, chemical of fire resistant characteristics of the electric cable sheath. However, there has not been quantitatively studied about the effect of coating stains on properties of sheath materials. In this study, we tried to investigate the effect of coating stains on the performance and deterioration of sheath materials by using FTIR, SEM analysis, flame retardant, high potential voltage and tensile test. The results sowed that coating stains, which were occurred during painting work on site could not adversely affect on the performance and deterioration of sheath materials.
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The latest trend of development for submarine oil field is caused by the drained oil and gas for ground field, and FPSO is a keyword as the development for submarine oil field. FPSO (Floating Production Storage Offloading) is a kind of vessel type have a topside system for production of oil and gas and store them until the oil or gas can be offloaded onto a tanker or transported through a pipeline. Prior to the introduction of reinforcement under the pull-in winch on the STP extended top as the object of this paper, the technical background shall be introduced such as FPSO and the system and main equipments for STP as follows. The original structural concept for reinforcement of pull-in winch on the STP top and extended structure on moonpool was proposed by buyer's engineering team but it was much modified and improved in accordance with builder's fabrication and construction method.
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The fouling around the surface of hull and propeller caused by marine organism and sea water occur in the vessel which is taken up mooring in a quay for a quite long time. Moreover, those are able to give rise to the loss of speed performance. The purpose of underwater cleaning is to improve the performance of vessel and customer satisfaction through management for fouling condition of propeller and hull. Therefore, systematic approach in connection with underwater cleaning is required so as to obtain the stable speed performance. As a result, we evaluate the effect of propeller polishing to speed performance from the case of 115K COT and 4,250 TEU Container Ship. In addition, we issue the importance of underwater cleaning through comparison of speed results depending on conditions of hull surface painted by silicon.
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The GSCAD (Global Shipbuilding CAD) System used in Samsung Heavy Industries is based on the Relation and Rule. The design area where excellence of these Relation & Rule can be used fully is pipe support modeling. That's because, many rules are required to place a pipe support and it's supported by hull structural object. Samsung Heavy Industries has been customizing the Relation and Rule supported by SmarMarine3d(R) to model pipe support easily and satisfies standard. Also, the pipe support fabrication drawing program was developed to generate a drawing for the pipe support customized. This paper reviews the characteristics of pipe support modeling on GSCAD and the Rules customized also, fabrication drawing program will be introduced.
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It is well known that a rudder is influential devices to help ship maintain its stable performances, such as a course-keeping and maneuverability. In the procedures of a commercial ship design proper rudder dimensions (area and shape) ensuring better ship maneuverability have been settled in an initial concept design stage performed by a preceding department, without little structural consideration. It is true that there are time discrepancy between an initial design and a structural analysis stage. Therefore structural analysis results would sometimes cause a rudder to modify its dimensions. Most of these cases, however, ship design and performance tests had been finished. In this matter, only limited modifications of redder could be carried out. Besides, these could also cause bad effects on productivity. Finally, it is necessary to develop a new program considering co-relationship between an initial rudder design and a following work, a structural strength analysis, in order to enhance productivity and minimize a rate of redesign procedures.
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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.
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The propeller induced forces acting on a hull are surface forces and bearing forces. The bearing forces are the forces acting directly on the propeller which are transferred to the hull through the propeller bearings. The surface forces are those which act by fluid pressure directly on the various hull surfaces. Because the surface force is main source to oscillate stern constructions and deckhouse, the estimation of surface force is very important to predict response of forced vibration of that. The estimation methods were statistical analysis method, theoretical analysis method and method through model test.
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In case that tug boat pushes side structures of other large vessels to maneuver, it is required that contacted side structures of the maneuvered vessels have enough structural safety against tug push loads. The objective of this study is to evaluate the structural effect of carling which is installed between side longitudinal stiffeners. A comparative study of side structures with carling and without carling is performed to evaluate the effect of carling member by both FE analysis. According to the result, it is found that the carlings play effective role in the strength of side plates and side longitudinal stiffeners against tug push loads.
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The world-wide ship construction market is forecast that the considerable portion of shipbuilding and oceanic plant industry will be transferred consequently in China after 5 or 10 years. This point of view where the Korean ship construction industry seizes the initiative from the world-wide ship construction/oceanic field, we must cultivate technical power of base technology, and focus our interests on the development of core parts. In this study, our proprietary remotely operated valve actuator system with power line technology was developed to enhance the installation and commissioning process by our own technology. This paper describes the new design and functions of the remotely operated valve system for shipbuilding and offshore market especially for FPSO.
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In order to improve productivity of large container ship construction, large heat input and/or high productive welding technologies are necessary. This can be achieved by the joint research and cooperation among steel maker, welding consumable company, welding equipment company and ship yards. Two electrodes SAW process is effective the plate butt welding and partial joint welding, while FGB welding process is for the connection of block to block joint. The higher strength and thicker steel is developed, the more reliable welding procedure such as two electrodes EGW including light weight welding equipment should be developed.
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CSR for bulk carrier has been required 25 years operation life in North Atlantic condition. As the fatigue life requirement of ship structure is increased it is necessary to study to satisfy the fatigue life which is much severe. Therefore from the fatigue analysis, especially fatigue strength for double bottom & lower stool connection area is not enough. To satisfy the fatigue life, it needs to increase double bottom strength or insert thicker plate. In this study, the consideration though structure modification have been doe with 81K bulk carrier and to find the solution of fatigue problem.
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Foundation structure for the main engine heavy spare parts in the engine room is susceptible to resonance problem due to outfitting weight. In addition the deck floor has a large opening for the main engine installation and maintenance, which further weakens the foundation structure. To reinforce the weak structure, two types of approaches have been used; 1) insert an H-pillar below or above the floor and 2) increase the stiffener size. In this paper, the H-pillar approach is used to solve the vibration problem of the foundation structure in the engine room opening area. A commercial program is used to analyze the vibration problem ad to find the location and the size of the H-pillar. Modal test at the quay and on-board vibration measurement during the sea trial have confirmed the validity of inserting an H-pillar below the floor.
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Many production methods are tried to enhance the productivity efficiency. Parallel connected floating cranes are one of the examples to lift mega-blocks quickly and efficiently. However, a general operation manual to operate parallel connected floating cranes and a method to consider risks during lifting operation are not confirmed. And if each floating crane is operated by itself, it is very hard to cooperate. Therefore, Synchronized operation system is installed to control parallel connected floating cranes simultaneously and to be informed of each floating cranes data. And weighting factor is calculated by considering all hazards during the operation and the general operation manual is confirmed based on the factor. This paper introduces the procedure for lifting operations by parallel Connected Floating Cranes using synchronized operation system, and its applications to lifting operation of a heavy cargo such as barge lifting test, floating dock installation and 900 ton goliath crane replacement operation, etc.
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In the recent large block are used to build the ship to improve productivity. For this reason, two or more floating cranes that are connected in parallel is the trend. Typically, when working with floating crane load safety factor is considered. Even in the parallel operation, load safety factor is calculated similar to working alone. For this reason, operations do not guarantee the reliability or excessive safety factor applied. Therefore, the subdivided cases for calculating the safety factor are defined when parallel connected floating cranes are operated. Based on those cases, the operation standard is made about procedure using parallel connected floating cranes. And to verify this, dynamics simulation was performed for verification using the dynamics simulation program.
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In shipbuilding process, automated marking systems are used to print steel part information on the steel plate. Especially, an automated marking system with a moving ink-head prints characters on each block, which divide the steel plate into a fixed size. Therefore it is necessary to split characters, because some characters can be extended into several blocks. Particularly the algorithm, which splits characters, must guarantee its printing quality in any direction since characters can be printed by any angle.
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Ship painting procedures can be divided into two categories; Out-shell plate painting of the hull and the interior painting of each double gull blocks. It is really hard to apply standardized and automated operations to the latter because the double hull blocks contains a variety of complicated supportive materials and pipes to strengthen the ship structure. In addition their poor working conditions cause painting workers to avoid working in them, resulting in the waste of paints and additional pollution issues. So this research, successfully focused on overcoming the difficulties in working in the complicated blocks and the tough working conditions introduces the main details of automatic equipment systems and their transfer algorism which show how the equipment paints the inner sides of a longitudinal stiffener and moves to another automatically.