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"Kemampuan Manuver Kapal dengan Sarat Kecil pada Kecepatan Angin Konstan. Gaya dan momen yang ditimbulkan oleh angin dapat mengakibatkan kecepatan operasi kapal berkurang secara drastis, sudut geser yang besar serta sudut kemudi yang besar untuk mempertahankan arah gerak kapal. Kapal dengan sarat yang kecil mempunyai kemungkinan yang lebih besar untuk mengalami masalah manuvering tersebut dibandingkan dengan kapal dengan sarat yang besar. Tulisan ini membahas performa manuvering kapal dengan sarat kecil pada kondisi angin dengan kecepatan konstan. Lima perbandingan kecepatan angin dan kecepatan kapal tersebut, yaitu 1,0, 5,0, 10,0, 15,0 dan 20,0 digunakan untuk simulasi. Arah data angin terhadap kapal divariasikan mulai dari 0° sampai 180°. Sudut geser kapal bertambah besar dengan bertambahnya kecepatan angin. Arah angin juga mempunyai pengaruh yang signifikan terhadap sudut geser khususnya pada sudut datang angin lebih kecil dari 140°. Fenomena yang sama terjadi pada kasus sudut kemudi. Sudut kemudi yang diperlukan untuk mempertahankan arah gerak kapal maksimum terjadi pada sudut datang angin 60° untuk perbandingan kecepatan angin dan kecepatan kapal (v/c) sama dengan atau lebih besar dari 20.0.

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Wind force and moment may force a ship to drastically decrease its speed and use a large drift angle as well as a large rudder angle in order to maintain its course. Ships with a small draught might have more risk in maneuvering to its point of view compared with a ship with a larger draught. This paper discusses maneuverability of a ship with a small draught in steady wind. The effect of wind on ship speed, drift angle, and rudder angle are investigated in a steady state condition. Five different ratios of wind velocity to ship speed from 1.0 to 20.0 are used in the simulation. The variation in wind direction is examined from 0° to 180°. Results of the numerical simulation show that the wind has a significant effect on the reduction in ship speed with a wind direction less than 100°. The drift angle increases due to increasing wind velocity in the same wind direction. Wind direction also has a significant effect on the drift angle especially when the wind direction is less than 140°. The same phenomenon was found for the rudder angle. The necessary rudder angle is greater than the maximum rudder angle of the ship when the wind direction is 60° with a wind velocity to ship speed ratio of 20 or more."

"A ship usually performs maneuvers under the influence of external forces and moments, such as wind, waves, and current. Therefore, it is important to understand the maneuvering behavior of ships under the action of external forces. This paper discusses the turning maneuvers of an Indonesian roro ferry under the combined influence of constant wind and regular waves using the mathematical modelling group (MMG). The ship’s position relative to the wave trough is added to the original MMG model to estimate the exciting forces and moment induced by the waves. The results of a numerical simulation show that the effect of wave height on turning ability is more significant for a small wavelength; this effect decreases as the wavelength increases. The effect of wavelength on the sway force and yaw moment is more significant compared with its effect on the surge force. The ship’s initial position relative to the wave trough does not have a significant effect on the turning characteristic and it can be neglected for the present study’s subject ship. Overall, the results of the present work compare well with published data."