Nippon Kokan Kabushiki Kaisha

Japan Marine Machinery Development Association

Takashi Watari

Satoshi Hoshino

Kazuhiko Yoshimi

Katsunori Kusumoto

Kazuyuki Shimizu

Hideki Namura

Morio Inoue

A method of controlling the speed of a ship equipped with a controllable pitch propeller at a predetermined value. A desired horsepower corresponding to a desired ship speed is obtained in accordance with the actual horsepower, the detected ship speed value and the preset ship speed value, and the rpm of the main engine is controlled in accordance with the desired rpm obtained in accordance with an engine loading function generator for minimum fuel consumption obtained in accordance with predetermined engine loading function generator for optimum propeller efficiency and a designed load characteristic function and the desired horsepower. A desired fuel rack position is obtained in accordance with the desired rpm and the desired horsepower and the desired fuel rack position is compared with the actual fuel rack position so as to control the blade angle of the propeller. By thus controlling the main engine rpm and the propeller blade angle, it is possible to maintain the speed of the ship at the value preset in accordance with the running schedule for all the changes in the running conditions and it is also possible to ensure the minimum fuel consumption for the preset ship speed.

Constant ship speed control method

A rigid marine sail has a rigid left sail portion and a rigid right sail portion, both of which are pivotally secured to a mast on a ship so as to be pivotable about one common pivot axis which extends substantially parallel to the mast of the ship. The common pivot axis is spaced ahead of the mast with respect to the direction of intended movement of the ship. The left and right sail portions are foldable to an operable position by pivoting them about the common pivot axis and are also foldable to a streamlined folded inoperable position by being pivoted about the one common pivot axis, the left and right sail portions being substantially parallel to each other and closely facing each other when they are in their streamlined folded inoperable positions. A shroud is provided ahead of the common pivot axis with respect to the direction of movement of the ship. When the left and right sail portions are in their folded inoperable position, the shroud spans a gap between them to reduce air resistance. When the sail portions are unfolded to their operable positions, only the left and right sail portions serve as sail members and they also shield the shroud from exposure to the wind.

Method for operating a rigid marine sail

Growing community of inventors

Kamakura, Japan

Takashi Watari