Estimation and Evaluation of Ship Performance in Actual Seas

Recently, the author reported a new method to estimate and evaluate long term ship performance in actual seas, including fouling and aging effect of hull, propeller and main engine. In the present paper, previous works are reviewed, concerning time depending effect in surface roughness of hull and propeller as well as log book analysis to verify for the method to be quantitatively reasonable as compare with these results. The calculation using the new method is carried out for five ships with different particulars of hull and propeller, to evaluate the influence of ship type and size on the fall of ship performance due to fouling, aging effect and sea condition.