In order to estimate the effective horse power(EHP) in towing net of a bottom trawl ship, the ship's resistance was calculated by using a series data of Yamagata and Wigley formula. Also the effective horse power for a ship(EHPs) was estimated versus the ship speed in sailing and the propulsive efficiency was calculated with the brake horse power and the effective horse power. Then the effective horse power for a ship and a trawl net were estimated in the application of the propulsive efficiency in towing net. The total effective horse power(EHPT) was average 187.6kW and the effective horse power for a 1.awl net(EHPn) was average 176.7kW at a smooth sea state in towing net. The ratio of EHPn to EHPT was about 94.0% and the value was higher slightly than was already informed at a smooth sea state. The power for keeping up a townet speed was required more about 20% of a maximum continuous power at a rather rough sea state than a smooth sea state. In the future, if the residual resistance is considered with a sea state, EHPn will be estimated more correctly Also the data of EHP estimated by this method will be used as the basic data to design a trawl net.

• 왕우경 | Wang, Woo-Kyung