Icebreaking additional propulsion system and icebreaking ship having the same

Abstract

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.

1 . An icebreaking additional propulsion system comprising: at least one retractable thruster capable of vertically moving into and out of a hull of a ship. 
   
   
       2 . The icebreaking additional propulsion system of  claim 1 , wherein 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.   
   
   
       3 . The icebreaking additional propulsion system of  claim 2 , wherein the drive unit includes a motor for swiveling the column and a cylinder for vertically moving the column. 
   
   
       4 . The icebreaking additional propulsion system of  claim 2 , wherein the retractable thruster further includes a bottom cover attached to a lower surface of the propeller and shaped to conform to a lower surface of the hull so that, when the retractable thruster is retracted, the bottom cover becomes flush with the lower surface of the hull. 
   
   
       5 . An icebreaking ship comprising:
 an icebreaking additional propulsion system; and   a side tunnel for maneuvering of the ship, wherein the extra propulsion system includes at least one retractable thruster capable of vertically moving into and out of a hull of the ship.   
   
   
       6 . The icebreaking ship of  claim 5 , wherein 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.   
   
   
       7 . The icebreaking ship of  claim 6 , wherein the drive unit includes: a motor for swiveling the column; and a cylinder for vertically moving the column. 
   
   
       8 . The icebreaking ship of  claim 6 , wherein the retractable thruster further includes a bottom cover attached to a lower surface of the propeller and shaped to conform to a lower surface of the hull so that, when the retractable thruster is retracted, the bottom cover becomes flush with the lower surface of the hull. 
   
   
       9 . The icebreaking ship of  claim 6 , wherein the retractable thruster is designed to ensure that the propeller comes into alignment with and communicates with the side tunnel when the retractable thruster is in a retracted state for maneuvering of the ship.