Off Vessel Tensioning System and Method

Abstract

Floating vessels or structures are moored to the sea floor by mooring line assemblies connecting the floating vessels to anchors fixed the seafloor. Disclosed is a method of tensioning the mooring line assemblies to a desired tension, without applying tension forces from the vessel or structure being moored.

I claim: 
     
         1 . A method, comprising the steps of:
 a) providing a mooring line assembly attached to an anchor, said anchor fixed to an ocean floor and said mooring line assembly run out on said ocean floor;   b) connecting an anchor handling vessel to said mooring line, said anchor handling vessel taking on at least a portion of a weight of said mooring line assembly;   c) positioning said anchor handling vessel proximal a floating vessel or structure to be moored, connecting said floating vessel or structure to said mooring line, and transferring said portion of said mooring line weight assembly to said floating vessel or structure;   d) moving said anchor handling vessel away from said floating vessel or structure to be moored, while the anchor handling vessel remains connected to the floating vessel or structure to be moored by a line, said anchor handling vessel moving to a selected position over mooring line assembly;   e) connecting the anchor handling vessel to said mooring line assembly by a hold-back line, said connection made at a point on said mooring line assembly between floating vessel or structure to be moored and said anchor;   f) tensioning said hold-back line from the anchor handling vessel, thereby applying a desired tension to said mooring line assembly;   g) connecting said mooring line assembly to said floating vessel or structure to be moored, so as to maintain said desired tension in said mooring line assembly;   h) slacking off of said hold-back line from said anchor handling vessel; and   i) disconnecting said hold-back line from said mooring line assembly.