• Title/Summary/Keyword: very large container vessel

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The Introduction of Shaft Alignment Calculation for very Large Container Vessel (초대형 콘테이너선의 축계정렬 계산 사례 소개)

  • Kang Dong Chun;Park Kun Woo;Kim Kyoung Ho
    • Special Issue of the Society of Naval Architects of Korea
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    • 2005.06a
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    • pp.138-143
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    • 2005
  • Recently, it is much more required to approach the accurate shaft alignment analysis according to the tendency of active showing in large container vessel and that of the heavy weight of propeller in connection with it. Shaft alignment calculation lies upon how the pressure apply on bearings properly in operation of main engine and how the stress of shaft puts within that of limit of bearing material and how the movement of shaft is prospected owing to propeller forces and moments. Therefore, we have conducted the shaft alignment calculation of very large container vessel considering the deformation of hull structure and the propeller forces and moments and the static and dynamic condition of shaft. The calculation results show the pressure distribution of aft bush and the movement of shaft in bearing. The shaft alignment calculation helps the stable application of shaft alignment, which was proved in sea trial.

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Study on Hydrodynamic Forces Acting on a Very Large Container Vessel at Lower Depths in Both Still Water and Waves (정수중 및 파랑중 저수심에서의 초대형 컨테이너선에 작용하는 유체력 특성에 관한 연구)

  • Lee, Sangmin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.6
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    • pp.613-619
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    • 2017
  • Recently, the size of container ships has been progressively increasing, and much attention is required for safe navigation in shallow areas such as coastal waters and ports due to increases in draft. It is necessary to understand the characteristics of ship motion not only in still waters but also with waves. Especially in shallow regions, squat due to the vertical movement of the ship can be an important evaluation factor for the safe navigation, and wave drift force acting in the horizontal direction can have a great influence on the maneuverability of a ship. In this study, a numerical simulation using computational fluid dynamics has been performed for the wave exciting force acting in the vertical direction and the wave drift force acting in the horizontal direction for a very large container vessel sailing in shallow zone. As a result, it was found that total resistance in still waters greatly increased in shallow water. Wave drift force was shown to decrease given longer wavelengths regardless of water depth. It was observed that the wave exciting force in shallow water was considerably larger than at other water depths. As wave height against the central part of the ship lowered, the aft side rose.

A study on the estimation of container terminal capacity and its implication to port development planning of Korea (국내 컨테이너 부두시설 확보제도 개선방향 연구)

  • Yang, Chang-Ho
    • Journal of Korea Port Economic Association
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    • v.26 no.3
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    • pp.198-220
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    • 2010
  • This paper investigate the problems of standard container port handling capacity in establishing national port development plan in Korea. Considering container port developing, it's not easy to adopt container port service quality parameters such as lay time constraint of very large container ships by using the standard guideline of container port handling capacity. A simple methodology that connects vessel waiting to service time(w/s) and berth occupancy to costs has been used to evaluate the performance of a container terminal. But the total handling capacity have to be calculated by the performance of the handling system and number of equipments and layout of terminal by using computer simulation that represents of reality events needs to be performed by probabilistic techniques. A simulation model of estimation of container terminal capacity is introduced in order to establish a hub terminal for very large container ships that focus the port's quality of service and also suggest as tool for policy maker to justify a required port investment.

Economic evaluation analysis for accommodation re-arrangement of 9,600TEU Container ship (9,600TEU급 컨테이너선의 거주 공간 재배치에 의한 경제성 평가 분석)

  • Choi, Kyong-Soon;Im, Nam-Kyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.325-332
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    • 2005
  • As ship builder companies have a tendency to pursuit the effect of scale economy, recently the ultra-large sized container ship is discussed very actively among them. It is expected that these situation will be continued for the time being. The need of accommodation re-arrangement is carefully proposed according to the tendency of ultra-large sized ship. In this paper, accommodation re-arrangement of ultra-large container ship is examined in the view of economy. We proposed separation of engine room and accommodation part through review and supplementaition of drawing generation in intial design stage. Also we investigated its merits and demerits to find out whether it can be realized or not in the view of economical efficiency. The RFR(Required Freight Rate) is considered as the objective function to evaluate the re-designed vessel. The economical benefits for increasing the number of TEU(Twenty-foot Equivalent Units)'s and the re-arranged space are analyzed in the view of ship owner and shipyards respectively.

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Hydroelastic Responses for a Ship Advancing in Waves (파랑중 전진하는 선박의 유탄성 응답)

  • 이호영;임춘규;정형배
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.4
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    • pp.16-21
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    • 2003
  • The very large container ships have been built recently and those ships have very small structural rigidity compared with the other conventional ships. As a result, the destruction of ship hull is occurred by the springing including to warping phenomena due to encounter waves. In this study, the solutions of hydrodynamic coefficients are obtained by solving the three dimensional source distribution method and the forward speed Green function representing a translating and pulsating source potential for infinite water depth is used to calculating the integral equation. The vessel is longitudinally divided into various sections and the added mass, wave damping and wave exciting forces of each section is calculated by integrating the dynamic pressures over the mean wetted section surface. The equations for six degree freedom of motions is obtained for each section in the frequency domain and stiffness matrix is calculated by Euler beam theory. The computations are carried out for very large ship and effects of bending and torsional ridigity on the wave frequency and angle are investigated.

A Study on Key Factors Affecting VLCC Freight Rate (초대형 원유운반선 운임에 영향을 미치는 주요 요인에 관한 연구)

  • AHN, Young-gyun;KO, Byoung-wook
    • The Journal of shipping and logistics
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    • v.34 no.4
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    • pp.545-563
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    • 2018
  • This study analyzes the major factors affecting the freight rates of Very Large Crude-Oil Carriers (VLCC) using co-integration and vector error correction models (VECM). Particularly, we estimate the long-term equilibrium function that determines the VLCC freight rate by conducting difference conversion. In the VECM regression analysis, the error term converges toward long-term balance irrespective of whether the previous period's freight rate is bigger or smaller than the long-term equilibrium rate. Thus, even if the current rate is different from the long-term rate, it eventually converges to the long-term balance irrespective of a boom or recession. This study follows Ko and Ahn (2018), which analyzed the factors affecting the chemical carrier freight rate and was published in the Journal of Shipping and Logistics (Vol. 34, No. 2). It is expected that an academic comparison of the results of each study will be possible if further research is conducted on other vessel types, such as container ships and dry cargo vessels.

Full Scale Measurement Data Analysis of Large Container Carrier with Hydroelastic Response, Part I - Identification of Modal Parameters (대형 컨테이너 선박의 유탄성 실선 계측 데이터 분석 Part I - 모달 파라미터 추정)

  • Kim, Byounghoon;Choi, Byungki;Park, Junseok;Park, Sunggun;Ki, Hyeokgeun;Kim, Yooil
    • Journal of the Society of Naval Architects of Korea
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    • v.55 no.1
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    • pp.37-44
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    • 2018
  • To understand the dynamic characteristics of the vessel with hydroelastic response, it is very important to estimate the dynamic modal parameters such as mode shapes, natural frequency, and damping ratio. These dynamic modal parameters of full scale ship are a priori unknowns, hence to be estimated directly based upon the full scale measurement data. In this paper, dynamic modal parameters were extracted by signal processing of acceleration and strain data measured from a large container ship whose loading capacity is 9400TEU. The mode shapes of the vibrating hull were identified using the proper orthogonal decomposition and the vibration response of hull was decomposed into its modal magnitudes. Natural frequencies of specific modes were derived via Fourier transform of these modal magnitude. Also, the free decay signal of the vibrating hull was obtained through the random decrement technique and the damping ratio was estimated with accuracy.

Fatigue Strength Assessment of A Longitudinal Hatch Coaming in a 3800 TEU Containership by ABS Dynamic Approach

  • Cui, Weicheng;Yang, Chunwen;Hu, Jiajun
    • Journal of Ship and Ocean Technology
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    • v.3 no.4
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    • pp.35-51
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    • 1999
  • Fatigue strength assessment procedures have been implemented in the ship design rules by many classification societies. However, a large variation tin the details of the different approaches exists in practically all aspects influding load history assessment, stress evaluation and fatigue strength assessment. In order to assess the influences of thesd variations on the prediction of fatigue lives. a comparative study is organized by the ISSC Committee III.2 Fatigue and Fracture. A pad detail on the top of longitudinal hatch coaming of a panamax container vessel is selected for fatigue calculation. The work described in this paper is one set of results of this comparative study in which the ABS dynamics approach is applied. Through this analysis the following conclusions can be drawn. (1) With the original ABS approach, the fatigue life of this pad detail is very low, only 2.398 years. (2) The treatment of the stillwater bending moment in the ABS approach might be a source of conservatism. If the influence of stillwater bending moment is ignored, then the fatigue life for this pad detail is 7.036 years. (3) The difference between the nominal stress approach and the hot spot stress approach for this pad detail is about 26%.

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Analytical Study on the Structural Strength of an Air Compressor for Main Engine Starting of 22000TEU Class Container Ships (22000TEU급 컨테이너선박의 메인 엔진 시동용 공기압축기의 구조 강도 해석에 관한 연구)

  • Kim, Soon-Kyoung;Lee, Jin-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.5
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    • pp.60-67
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    • 2015
  • The compressor is used for many fields not only in the industrial sector, but also as a general household product. The energy consumption required for the compressor operation is very large. The reciprocation compressor is widely used as an air compressor. Regarding the reciprocating air compressor, the discharge of the gas compacted by the method of compressing the gas by using the oscillation of the piston is generated by the piston reciprocation 1 church 1 number. When compressing after compressing the air by the oscillation of the piston, the marine reciprocating air compressor is the vibration generated in the compressor and surrounding structure due to the energy of the generated inertia. If the effect of these harmful elements can be reduced, it supports the service of the vessel. In addition, accidents generated by the noise of the vibration can be prevented. Therefore, in this research, firstly, the structural analysis of the piston part was performed, the safety factor in all results was drawn based upon this, and the reliability of the interpretation was examined in order to create the optimal design for the air compressor.