Author(s)

H. Zeraatgar

Abstract

For some kind of ship such as container vessel time schedule is very rigid. Delay causes penalties. Due to rough sea conditions, it is not so easy to calculate the exact time length of a trip. In this work an attempt has been made to predict ship service speed in the real seaway by taking into account hydrodynamic effects of sea waves and winds on ship service speed. To do this a mathematical model is presented which takes into account voluntary and involuntary speed reduction. Having known a route, ship and its propulsion system specification and all sea waves and winds during the ship trip, all speed reduction is calculated. A mathematical model based on probabilistic approach has been developed to add the share of each speed reduction due to single wave and wind. The final speed reduction of a ship in specified route may be achieved based on the le

Keywords