摘要 |
An icebreaking additional propulsion system includes at least one retractable thruster capable of vertically moving into and out of a hull of a ship. The retractable thruster includes a pair of guide rods vertically installed within the hull, a column vertically movable along the guide rods, a drive unit mounted to an upper end of the column for vertically moving and swiveling the column, and a propeller attached to a lower end of the column for generating propelling power.
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