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NAOSITE : Nagasaki University's Academic Output SITE > Faculty of Fisheries > Bulletin > Bulletin of the Faculty of Fisheries > 第35号 >

実船試験による小型漁船の耐航性について-1 : 以西底曳網漁船の動揺特性


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Title: 実船試験による小型漁船の耐航性について-1 : 以西底曳網漁船の動揺特性
Other Titles: On the Sea Keeping Qualities of Small Fishing Boat by Field Measurements―I The characters of fluctuation of the bull trawler
Authors: 西ノ首, 英之
Authors (alternative): Nishinokubi, Hideyuki
Issue Date: Aug-1973
Publisher: 長崎大学水産学部
Citation: 長崎大学水産学部研究報告, v.35, pp.91-102; 1973
Abstract: The condition of a fishing boat is very different between her departure and arrival, i.e., between outward and homeward voyage, during fishing operation, before and after transshipping of fish from catching boat to fish carrier, and therefore her motions are also different. This paper deals with the rolling, pitching and heaving motions of the response oscillation of the ship under various sea conditions. A series of field measurements were carried out on board three bull trawlers (No.97 Choyo Maru, Nos. 23 and 51 Tokai Maru; 140 G.T.). The variation of each oscillation was recorded continuously for about 12 minutes in the 4 channel data recorder, while the sea conditions were observed by naked-eyes. The characters of oscillation such as rolling, pitching and vertical accelerations were obtained by the method of statistical analysis of the stochastic processes. Accordingly, the several substantial results are: 1) Although it is assumed that measured values of respective rolling, pitching and heaving motions under a certain sea condition are much the same, different values were observed. For instance, the rolling values in the bow sea under the pitching values in the head sea fluctuated under same sea condition. 2) During a fishing operation period (about 3 hours) the change of three motions is very small. 3) The rolling and heaving motions of the fishing boat in the fishing operation are greater than those in the voyage. However, the pitching is less conversely. 4) The author found a comfort index from the result of the measurment of vertical acceleration. The greater is the comfort index, the comfort becomes worse. The comfort, based on the comfort index, is the best in the fishing commander's bed and then in wireless operater's bed. There is a tendency that the comfort becomes worse in proportion tothe distance from the center of the ship. / 以西底曳網漁船の実船試験によって,Rolling, Pitchingおよび上下加速度についての統計的動揺特性は次の通りであった。1. 目視観測による海況階級が等しく,波と船との各出合い角度別の3運動の動揺特性は,Head seaのとき,2回の計測結果ではRollingとHeavingは周期,振巾共に相違はないがPitchingは,周期は等しいが振巾は異なった。Bow seaのときは,Rollingの振巾が3回の計測で各々異なった値を示した。Beam seaのときは,3回の計測結果が3運動共に相違は少なかった。スペクトラムからPitchingにはRollingの固有周期が表われる。またHeavingのスペクトラムにはPitchingのスペクトラムの変動分がRollingのそれより多く含まれている。2. 約2時間30分の一曳網中における3運動の動揺特性には時間の経過に伴なう変化は認められない。従って魚の入網効果による運動の変化は無視できる。3. 操業中と航海中との運動の平均振巾値の比較は,Quartering seaの場合,RollingとHeavingは操業中の方が大きくPitchingはわずかながら航海中の方が大であった。4. 船の乗心地指標を乗組員の各寝台で計測された上下加速度をもって比較した場合,最も良好であったのは船橋の漁撈長の寝台で,次いで通信長および船長の寝台であった。一般乗組員の寝台問では明らかな順序はつけ難いが船首に近い程悪い傾向が認められる。
URI: http://hdl.handle.net/10069/30887
ISSN: 05471427
Type: Departmental Bulletin Paper
Text Version: publisher
Appears in Collections:第35号

Citable URI : http://hdl.handle.net/10069/30887

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