Patent ID: 9021970
Filing Date: 2015-05-05
Classification: B63B,B63H

Abstract:
1. A propulsion device of a ship, the propulsion device comprising: a port side screw propeller; and a starboard side screw propeller provided in a forward or backward direction in a longitudinal direction of the ship from said port side screw propeller, such that a part of propeller wings of said starboard side screw propeller overlaps with propeller wings of said port side screw propeller, wherein one of said port side screw propeller and said starboard side screw propeller, which is on a forward side in a longitudinal direction of the ship, is a forward screw propeller, and the other is a backward screw propeller, and wherein the number of propeller wings of said forward screw propeller is more than the number of propeller wings of said backward screw propeller.