Semi-submersible vessel

Abstract

An uncrossed-braced, column stabilized semi-submersible and improved methods of operation of the same are disclosed. The semi-submersible vessel provides necessary strength to resist hydrodynamic forces via a unitized support system. Improved elliptically shaped columns, haunch supports and reinforcing members provide stability and resist transverse forces. A skirt design minimizes the reduced stability at the transition point. Improved deck designs reduce environmental impacts and provide additional support against transverse forces.

What is claimed is:  
     
         1 . A vessel comprising: 
 at least one elliptically shaped column wherein: 
 said column compromises a first end and a second end; and  
 said second end of said column is flared, whereby said second end has a greater surface area than said first end;  
   at least one pontoon, wherein said second end is connected to said pontoon; and    a deck, wherein said deck is connected to said first end.    
     
     
         2 . The vessel of  claim 1 , wherein said deck is connected to said first end by a haunch.  
     
     
         3 . The vessel of  claim 1 , wherein said column comprises a skin, wherein said skin flares inboard toward said deck at said first end to provide structural support.  
     
     
         4 . The vessel of  claim 3 , wherein said skin flares inboard at an angle between twenty and sixty degrees.  
     
     
         5 . The vessel of  claim 4 , wherein said pontoon comprises a front and an aft end, wherein said front end is tapered.  
     
     
         6 . A vessel comprising: 
 at least one pontoon, wherein said pontoon comprises a length and a width;    at least one column, wherein said column comprises: 
 a height, width, and depth, wherein the width of said column is greater than the depth of said column; and  
 a first end and a second end, wherein said first end is connected to said pontoon and oriented such that the width of said column is generally parallel to the length of said pontoon, whereby said column is elliptically shaped; and  
 a deck connected to said second end.  
   
     
     
         7 . The vessel of  claim 6 , wherein said length of said pontoon is greater that the width of said column.  
     
     
         8 . The vessel of  claim 7 , wherein said column comprises an outer skin, and said outer skin flares inboard.  
     
     
         9 . The vessel of  claim 7  wherein said column is connected to said deck by a haunch.  
     
     
         10 . The vessel of  claim 7 , wherein said column width is at least one and one-half times greater than said column depth.  
     
     
         11 . The vessel of  claim 10 , wherein said deck is a horizontal box, wherein said horizontal box comprises a first deck, a second deck and a wet deck, wherein said wet deck and said second deck are connected by a plurality of support members.  
     
     
         12 . The vessel of  claim 11 , wherein said first end of said column is flared.  
     
     
         13 . The vessel of  claim 12 , wherein said vessel is a semi-submersible vessel.  
     
     
         14 . The vessel of  claim 13 , wherein said columns comprise a plurality of internal supports.