To provide a boat lifting device suppressing any turn of a boat to be lifted when the boat is lifted or lowered.
The boat lifting device comprises: a first winch device 5 for winding/delivering a plurality of first wire ropes 8, 9 connected to a first boat to be lifted; a second winch device 6 for winding/delivering a second wire rope 10 connected to a second boat to be lifted; a portal davit 4 which is constituted in a portal shape of a pair of stays and a beam stretched between the stays and tiltably mounted on a deck of a lifting boat; hydraulic cylinders 7a, 7b for controlling the tiltation of the portal davit 4; and a control device for controlling the winding/delivery so that the plurality of first wire ropes 8, 9 are also connected to the second boat and the tension of the plurality of first wire ropes is equal to or less than the predetermined value when lifting/lowering the second boat to be lifted by winding/delivering the second wire rope 10 connected to the second boat by the second winch device 6.
Masahiro Fujii
Masaaki Iida
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