Patent ID: 7681748

Claim:
A hoisting device with a vertical motion compensation function that is located on a ship, comprising: a hydraulic motor rotating a drum having a wire wound thereon, which is rotatable in normal and reverse directions; a hydraulic pump directly connected, and supplying operating oil to said hydraulic motor; an electric motor rotationally driving said hydraulic pump; a wire speed sensor detecting a speed of the wire; a vertical motion sensor detecting a vertical motion of a hanging point of the wire payed out and hung from the drum, the vertical motion being caused by a vertical motion of the ship; and a control unit paying out or rolling up the wire by controlling a discharge amount of said hydraulic pump based on a detected signal of the vertical motion sensor and a detected signal of the wire speed sensor to eliminate effects of the vertical motion of the hanging point operating on the wire, wherein the hanging point of the wire is a point from which the wire hangs.