Heave plate on floating offshore structure

Abstract

A floating offshore structure having a buoyant hull with an open truss frame having heave plates vertically spaced along the truss frame. One or more of the heave plates include a skirt plate that is attached around the outer perimeter of the heave plate and increases the effectiveness of the heave plate at trapping water mass between the heave plates for reducing heave motions of the floating offshore structure. A skirt plate is attached to one or more heave plates at essentially a right angle to the heave plate. The skirt plate may extend beyond the upper and lower surfaces of the heave plate or be positioned so as to be flush with the one surface of the heave plate and extend only beyond the opposite surface of the heave plate.

1 . In a floating offshore structure having a buoyant hull, an open truss frame rigidly attached to and extending below the hull, and at least two horizontally oriented heave plates attached to and spaced vertically apart along the length of the open truss frame, a skirt plate rigidly attached to the outer edge of at least one heave plate at essentially a right angle to the heave plate and extending beyond at least one surface of the heave plate. 
     
     
         2 . The skirt plate of  claim 1 , wherein the skirt plate is attached around the full perimeter of the heave plate. 
     
     
         3 . The skirt plate of  claim 1 , wherein at least one skirt plate is flush with the one surface of the heave plate and extends beyond the opposite surface of the heave plate. 
     
     
         4 . In a floating offshore structure having a buoyant hull, an open truss frame rigidly attached to and extending below the hull, and at least two horizontal heave plates attached to and spaced vertically along the length of the open truss frame, a skirt plate rigidly attached to the outer edge of at least one heave plate at essentially a right angle to the heave plate and extending beyond at least one surface of the heave plate, with the skirt plate attached around the full perimeter of the heave plate.