Elucidation of the mechanism of anchor dragging of ships in adverse weather conditions and its prevention

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02370
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 24020:Marine engineering-related
• Research Institution: Hiroshima University
• Principal Investigator: Yasukawa Hironori 広島大学, 先進理工系科学研究科(工), 教授 (40363022)
• Co-Investigator(Kenkyū-buntansha): 佐野 将昭 広島大学, 先進理工系科学研究科(工), 准教授 (40582763) ; 平田 法隆 広島大学, 先進理工系科学研究科(工), 助教 (80181163)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 漂流 / 走錨 / 水槽試験

Outline of Final Research Achievements

The purpose of this study is to elucidate the mechanism of ship drifting after dragging anchor under wind and waves. The study was achieved through tank tests using a scale ship model and motion simulations of the ship based on dynamics/hydrodynamics. The flow of the research is as follows: 1. simulations of anchor dragging under wind and waves by the tank tests and understanding of subsequent ship drifting phenomenon, 2. development and validation of the calculation model for ship drifting in wind and waves, 3. theoretical consideration for mechanism of the phenomenon.
As a result, when the ship begins to drift after dragging the anchor, it drifts almost sideways regardless of the disturbance conditions. It turned out that this is because the condition drifting sideways is kinematically the most stable. In addition, a theoretical calculation method for such movements was developed.

Free Research Field

海洋工学

Academic Significance and Societal Importance of the Research Achievements

今まで，走錨後の船の漂流の特徴を明らかにした人はおらず，また，それらの現象を理論計算によってシミュレートした人もいなかった。今回の研究により，浮体の運動学の視野が大きく広がったと考えられる。
社会的には，走錨発生後の船の漂流のメカニズムが解明されたことによって，その防止法を策定することが容易となった。運悪く走錨後に船の漂流が始まると，船は真横に流されてゆくので，その特性を踏まえて，事故の対策を取る必要がある。この船の漂流の予測には，今回開発した理論計算法が使用できる。これによって，強風下における船舶の海難事故の低減が期待できる。