Drifting of a dead ship in wind

• Published in: Ship technology research = Schiffstechnik Vol. 70; no. 1; pp. 26 - 45
• Main Authors: Yasukawa, Hironori, Hirata, Noritaka, Nakayama, Yoshiyuki, Matsuda, Akihiko
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 02.01.2023
• Subjects: dead ship; Drift motion; free-drift model test; motion stability in wind; simulation model
• ISSN: 0937-7255; 2056-7111
• DOI: 10.1080/09377255.2021.1954835

The drift characteristics in wind of a dead ship that cannot sail on its own are investigated experimentally and theoretically. First, a free-drift test of a bulk carrier model in wind is conducted. Next, a time-domain simulation method is developed for predicting the drift motion of the dead ship in wind. Tank tests and motion simulations show that the dead ship drifts with a large hull drift angle over in wind, and the converged drift angle is independent of wind speed and initial ship heading angle. To explain why the dead ship drifts with a large drift angle in wind, a theoretical formula is derived for investigating the motion stability of the dead ship in wind. It is theoretically confirmed that the ship drifts stably with a large drift angle over in wind, whereas drift angles of and result in unstable motion. Thus the reason for the drift behaviour of the dead ship is clarified.