Floating structure having propulsive devices for moving the same while sailing and mooring

Abstract

Disclosed is a floating system. The floating system comprises a floating body, a first propeller and a second propeller. The first propeller is pivotally secured to the floating body. The second propeller is pivotally secured to the floating body and distanced from the first propeller in a first direction and in a second direction perpendicular to the first direction. The first and second directions are generally parallel to a surface of water on which the floating system floats.

1 . A ship comprising:
 a hull having a length in a longitudinal direction and a width in a lateral direction perpendicular to the longitudinal direction;   a first propeller secured to the hull and configured to propel the ship; and   a second propeller secured to the hull and configured to propel the ship, wherein the second propeller is distanced from the first propeller both in the longitudinal and lateral directions.   
   
   
       2 . The ship of  claim 1 , wherein at least one of the first and second propellers is configured to pivotally rotate while secured to the hull. 
   
   
       3 . The ship of  claim 1 , wherein the first and second propellers are closer to a rear end of the ship than to a front end of the ship. 
   
   
       4 . The ship of  claim 1 , wherein a first distance from the first propeller to a rear end of the ship is smaller than a second distance from the second propeller to the rear end of the ship. 
   
   
       5 . The ship of  claim 1 , wherein the hull comprises a center line extending in the longitudinal direction between front and rear ends thereof, wherein the first propeller is on one side of the center line and the second propeller is on the other side of the center line. 
   
   
       6 . The ship of  claim 5 , wherein the center line is closer to the second propeller than to the first propeller. 
   
   
       7 . The ship of  claim 1 , wherein the first and second propellers are arranged along an imaginary straight line which is substantially tilted from the longitudinal direction. 
   
   
       8 . The ship of  claim 7 , wherein the imaginary line is tilted from the longitudinal direction forming an angle therebetween from about 10° to about 80°. 
   
   
       9 . A floating system comprising:
 a floating body;   a first propeller pivotally secured to the floating body; and   a second propeller pivotally secured to the floating body and distanced from the first propeller in a first direction and in a second direction perpendicular to the first direction, wherein the first and second directions are generally parallel to a surface of water on which the floating system floats.   
   
   
       10 . The floating system of  claim 9 , wherein the floating body comprises a stem and a stern, wherein the first and second propellers are located closer to the stem than to the stem. 
   
   
       11 . The floating system of  claim 9 , wherein the floating body comprises a stem and a stern, wherein the floating body generally extends in the first direction from the stem and the stem. 
   
   
       12 . The floating system of  claim 9 , wherein the first and second propellers are arranged along an imaginary line which is slanted with respect to the first direction. 
   
   
       13 . The floating system of  claim 12 , wherein the imaginary line and the first direction define an angle from about 10° to about 80°. 
   
   
       14 . The floating system of  claim 13 , wherein the angle is from about 30° to about 60°. 
   
   
       15 . The floating system of  claim 9 , further comprises a mooring structure configured to be fixed to a seabed or land, wherein the floating body is pivotally connected to the mooring structure. 
   
   
       16 . The floating system of  claim 15 , wherein the first and second propellers are configured to, in combination or alone, apply a propulsive force to the floating body so as to move around the mooring structure. 
   
   
       17 . The floating system of  claim 9 , wherein the first propeller is configured to pivot with respect to the floating body between a first sailing position and a first mooring position, wherein the second propeller is configured to pivot with respect to the floating body between a second sailing position and a second mooring position. 
   
   
       18 . The floating system of  claim 17 , wherein the floating body is configured to sail substantially straight when the first and second propellers are set in the first and second sailing positions. 
   
   
       19 . The floating system of  claim 17 , wherein the floating body is configured to move around the mooring structure when the first and second propellers are set in the first and second mooring positions. 
   
   
       20 . The floating system of  claim 17 , wherein the first propeller is configured to apply a first propulsive force to the floating body at the first sailing position generally in a fourth direction, wherein the second propeller is configured to apply a second propulsive force to the floating body at the second sailing position generally in a fifth direction, wherein the floating body further comprises a rudder configured to control sailing of the floating body in the first direction. 
   
   
       21 . The floating system of  claim 20 , wherein the fourth and fifth directions are substantially parallel to the first direction. 
   
   
       22 . The floating system of  claim 17 , wherein the first propeller is configured to apply a first propulsive force to the floating body at the first sailing position generally in a fourth direction, wherein the second propeller is configured to apply a second propulsive force to the floating body at the second sailing position generally in a fifth direction, wherein the fourth and fifth directions are substantially nonparallel. 
   
   
       23 . The floating system of  claim 9 , wherein the floating body is selected from the group consisting of an LNG tank ship, an LNG RV, an LNG FPSO and an LNG FSRU. 
   
   
       24 . A method of operating a floating system, the method comprising:
 providing the floating system of  claim 9 ;   engaging the floating body with a mooring structure fixed to a seabed; and   running the first and second propellers so as to rotate the floating body around the mooring structure while the floating body s engaged with the mooring structure.   
   
   
       25 . The method of  claim 24 , further comprising:
 disengaging the floating body from the mooring structure; and   running the first and second propellers so as to sail the floating body away from the mooring structure.   
   
   
       26 . The method of  claim 25 , further comprising:
 pivoting the first propeller with respect to the floating body to a first sailing position; and   pivoting the second propeller with respect to the floating body to a second sailing position, wherein running the first and second propellers so as to sail the floating body comprises:
 operating the first propeller to apply a first propulsive force to the floating body at the first sailing position generally in a fourth direction; and 
 operating the second propeller to apply a second propulsive force to the floating body at the second sailing position generally in a fifth direction, 
 wherein the fourth and fifth directions are substantially parallel to the first direction. 
   
   
   
       27 . The method of  claim 25 , further comprising:
 pivoting the first propeller with respect to the floating body to a first sailing position; and   pivoting the second propeller with respect to the floating body to a second sailing position,   wherein running the first and second propellers so as to sail the floating body comprises:
 operating the first propeller to apply a first propulsive force to the floating body at the first sailing position generally in a fourth direction; and 
 operating the second propeller to apply a second propulsive force to the floating body at the second sailing position generally in a fifth direction, 
 wherein the fourth and fifth directions are substantially nonparallel. 
   
   
   
       28 . The method of  claim 24 , wherein the floating system comprises a LNG tank configured to contain LNG, wherein the method further comprises loading or unloading LNG into or from the LNG tank while the floating system moors. 
   
   
       29 . The method of  claim 24 , wherein the floating system comprises a LNG tank containing LNG and a LNG vaporizer, wherein the method further comprises vaporizing the LNG and transmitting the vaporized LNG to a valve port connected to an onshore LNG supplying system.