PURPOSE: To prevent a mooring wires on the ice sea from being broken by a method wherein a stem mooring wire is held by a bollard on a deck of an ice-sea structure of single leg having a dash plate for preventing the ice from riding thereon, and a stern mooring wire is held by a mooring buoy fixed to an anchor driven into the seabed.

CONSTITUTION: When mooring the ship 10 to the one-leg ice-sea structure 1, the deck 3 having the dash plate 4 for preventing ice blocks from riding thereon is provided around the structure 1, and the stem mooring wire 6 of the ship 10 is held by the bollard 5 provided on the deck 3. On the other hand, the stern mooring wire 7 is held by the mooring buoy 9 fixed to an anchor 8 driven into the seabed. The mooring wires 6, 7 are present above the ice sea surface, they are not applied with large forces from drift ice, and such accidents as breaking of the wires can be prevented.