Positioning system for pipe-laying ships - uses winches and electric motor driven propellers to eliminate rocking motion of ship

摘要

The positioning system for ships laying pipes in deep water controls the winches that hoise the ship's anchor cables such that the ship moves in the reouired direction. A compensation force is exerted on the ship by the winches by driving in conjunction with the forces produced by the winches. The course, direction and magnitude of the compensation force is controlled by electric propellors in conjunction with the forces produced by the winches such that the resulting force acts against the central elastic force and the oscillating motion of the ship is nullified. The positioning propellers are driven by electric motors.