Patent ID: 11915595
Assignee: JAPAN HAMWORTHY & CO., LTD.
Field: Transport (Mechanical engineering)
Classification: CPC G  B | IPC B  G

Claim 5:
6. A collision-avoidance maneuvering system for a single-propeller twin-rudder ship, the single-propeller twin-rudder ship comprising a propulsion propeller disposed at a stern of an own ship, a pair of right and left high-lift rudders disposed behind the propulsion propeller, a pair of rotary-vane steering engines for driving the respective high-lift rudders, a steering controller for controlling a direction of a ship motion by combining rudder angles of the two high-lift rudders, and a ship radar,
wherein in a collision-avoidance maneuvering mode for navigation in congested water, the steering controller performs collision-avoidance maneuvering in response to a collision alarm signal transmitted from the ship radar when another ship crossing a course of the own ship is likely to collide with the own ship, the own ship being decelerated so as to avoid collision with the other ship by astern power against an inertial force applied in a forward direction of the own ship, the own ship being continuously navigated on a current target course while viewing the other ship on a starboard side with the propulsion propeller always rotated forward, the astern power being generated as propulsion of a propeller slipstream with rudder angles formed at the high-lift rudders,
in the decelerating maneuvering, the rudder angles formed at the high-lift rudders are set at a rudder angle for applying a maximum propeller slipstream as the astern power, a number of revolutions of the propulsion propeller is changed with a constant forward rotation, the astern power that changes with the number of revolutions of the propeller is controlled according to a distance from the other ship, and a speed of the own ship is reduced so as to obtain a time required for the other ship to cross the course of the own ship, and
the rudder angles of the high-lift rudders are controlled so as to continuously navigate the own ship on the target course by using the propulsion of the propeller slipstream as the ahead power after the other ship crosses the course of the own ship.