Ship Speed Control to Minimize Fuel Consumption-V : Effects of Winds and Waves

Abstract

It is said that the sea margin of a ship amounts up to 15% of fuel consumption in still water. The margin is devided into four parts: effects of winds and waves, fouling, ocean currents, and unknown factors. In this report, the effects of winds and waves are estimated from log-book of a tanker sailing between Japan and Persian Gulf. The performance curves of ship speed loss and fuel increase on a constant revolution of propeller are obtained. When these curves, estimated fouling effect and the r.m.s. of errors is reduced under the half of the original value. The frequency distribution of seasonal fuel increase due to winds and waves are also shown.