• Title/Summary/Keyword: Main hull form characteristics

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Study on Resistance Performance of Icebreaking Cargo Vessel in Pack Ice Condition according to Variation of Synthetic Ice Thickness and Hull Form Characteristics (합성얼음의 두께변화와 선형변화에 따른 Pack ice 상태에서의 쇄빙상선의 저항특성 연구)

  • Lee, Seung-Ho;Kim, Moon-Chan;Chun, Ho-Hwan;Cho, Jun-Cheol;Shin, Byung-Chul;Jung, Un-Hwa
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.5
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    • pp.471-478
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    • 2009
  • The present paper deals with characteristics of resistance performance according to the variation of synthetic ice thickness and hull form. The resistance test has been conducted with pack ice condition in Pusan National University towing tank. Stem angle has been chosen as main parameters for the variation of hull form characteristics, which is the most important factor especially in icebreaking cargo vessel. The serial comparisons of resistance test have been done with the variation of hull form parameter as well as with the different thickness of synthetic ice. The different trend of resistance performances with increasing of stem angle has been shown at each synthetic ice thickness. The present test results is expected to be confirmed by comparing the test results in ice tank in the near future.

A Preliminary Study about the Stern Hull Form Design of Ship with Transom Stern (트랜섬 선미를 가지는 선박의 선미선형 설계에 관한 기초적 연구)

  • Lee Young-Gill;Kim Kyu-Seok;Kang Dae-Sun;Jeong Kwang-Leol
    • Journal of Ocean Engineering and Technology
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    • v.20 no.3 s.70
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    • pp.88-95
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    • 2006
  • The resistance characteristics of a trimaran are studied, varying the bottom profile and transom stern of the main hull. The bottom profile is varied in three cases (convex, flat, concave). Using the experimental and numerical methods, the resistance performance of each hull form is compared. The experiments are carried out in ship model basin, and the numerical simulations are performed by a finite-difference method, based on the Marker and Cell scheme. Euler and continuity equationsare used for the governing equations of the flaw field around a trimaran with transom stern. The agreement of both results is good. The optimal bottom profiles for transom stern are presented for law-speed and high-speed regions, respectively.

Estimation of drafts and metacentric heights of small fishing vessels according to loading conditions

  • Kim, Dong Jin;Yeo, Dong Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.199-212
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    • 2020
  • A large percentage of maritime accidents in coastal seas are related to small fishing vessels. In order to investigate causes of maritime accidents, it is often necessary to carry out dynamic simulations for the estimation of trajectories and motions of vessels. Initial conditions of vessels such as main dimensions, loading conditions and hydrostatic properties are required for the accurate simulations. Small fishing vessels usually have few records of hydrostatic properties during their fishing operations. Therefore, in this study, estimation procedures for hydrostatic properties of small fishing vessels are proposed. At first, hull form characteristics of Korean small fishing vessels are investigated. Most of vessels have hard-chines and centerline skegs, they have similar hull forms. Bonjean curves of several small fishing vessels whose gross tonnages are below 10 tons are normalized with vessel breadths and depths. Representative bonjean curves are derived from normalized bonjean curves, and a representative hull plan is obtained as well. If the vessel loading conditions such as total weights and centers of gravity are given, fore and aft drafts can be calculated by using the representative bonjean curves with the constraint that weights and buoyancies are in equilibrium. Metacentric heights are also estimated by using the representative hull plan. Drafts and metacentric heights estimated by proposed iterative estimation procedures are compared with actual vessel data, estimated values are in good agreements with actual values. In addition, normalized fore and aft drafts, metacentric heights of vessels can be formulated as the linear functions of normalized total weights and centers of gravity. Empirical formulas of drafts and metacentric heights are proposed, and it is confirmed that the empirical formulas also provide reasonable results, which are similar to the results by iterative estimation procedures with representative bonjean curves and hull plan.

Characteristics of Korean Inshore Fishing Boats (한국(韓國) 연근해어선(沿近海漁船)의 특성(特性))

  • Keuck-Chun,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.8 no.1
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    • pp.67-94
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    • 1971
  • Korean fisheries industry holds 57,255 boats amounting to 269,079 tons in gross as of the end of 1967. The boats of the size under 30G.T., about sixty-two per cent of the total in tonnage, are utilized in coastal and their contribution to the total production of Korean fisheries industry is estimated at over seventy-five percent. Hull forms and construction method of them are partly in transition stage to the western tradition from the oriental tradition, which employs the chine-type straight-framed section, and tick and wide wooden planking fastened on naturally bent timber frames. And only about a half of them are mechanized. About fifty-seven per cent, 7,525 boats amounting to 91,751 gross tons, of the coastal and inshore fishing boats are those of the size ranging 5G.T. to 30G.T., which are engaged mostly in draft-and gill-netting, angling, longlining, anchovy seining, squid fishing and set-netting. The important fishing boats forming main structure of the inshore fishing fleets can be classified as 5G.T.-class multi-purpose boats, 10G.T.-class angling/longlining boats and 20G.T.-class drift-/gill-netters mostly utilized in the east-sea, 15G.T.-class anchovy seiner in the south-sea-sea, 20G.T.- and 28G.T.-class stow-netters in the west sea. Each of the three sea regions, east, south, and west, of Korean water has distinctly different characters from one another in topography, geology and sea aspects, and consequently in marine resources, fishing grounds and fishing tactics desired. Hence, the finishing boats in each sea region have also their own characters in hull form, structural features, deck design and equipments. In this report, analyzing the characteristics of the existing inshore fishing boats ranging 5G.T. to 30G.T. in size from view points of naval architecture and engineering, the author made an integrated investigation of their characteristics, covering size and principal dimensions, hull form, deck design, structural features and mechanization, in close connection with the natural circumstances of Korean water and local techno-socio-economic problems, and, finally, made some suggestions for the rational improvement or modernization of the inshore fishing boats. Further details of the characteristics of Korean inshore finishing boats are referred to the drawings of them compiled by the author and given in the reference[23] listed at the end of this report.

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The Floating Drilling, Production, Storage, and Offloading Vessel for the Large Deepwater Field Development

  • John Halkyard;Park, Guibog;Igor Prislin;Atle Steen;Phil Hawley
    • 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.

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