Apparatus and method of installation of a mono-column floating platform

Abstract

In a floating platform, temporary buoyancy modules detachably mounted on the hull of the floating platform are provided. Each temporary buoyancy module is provided with removable winches for developing initial pre-tension of pre-installed tendons for anchoring the platform at the installation site.

1 . A floating platform comprising a hull having a deck mounted on the upper end thereof extending above the water line and pontoons extending radially outwardly from the base of the hull, the improvement comprising temporary buoyancy means mounted on said pontoons at the distal ends thereof for maintaining the hydrostatic stability of said platform during installation.  
   
   
       2 . The floating platform of  claim 1  wherein said temporary buoyancy means comprises a removable ballast tank secured on said pontoons at the distal ends thereof.  
   
   
       3 . The floating platform of  claim 2  including a dry deck on said ballast tank supporting at least one winch thereon for connection with pre-installed tendons for developing initial pre-tension of said tendons.  
   
   
       4 . The floating platform of  claim 1  wherein said temporary buoyancy means is hingedly secured to said pontoons.  
   
   
       5 . A method of installing a floating platform, comprising the steps of: 
 a) providing said platform with removable temporary buoyancy means for maintaining hydrostatic stability of said platform while ballasting down to the installation draft of said platform;    b) towing said platform to an installation site;    c) ballasting down said platform to an installation draft;    d) connecting said platform to the pre-installed tendons;    e) removing said temporary buoyancy means; and    f) deballasting said platform to develop the tendon pre-tension required to provide stability to said platform.    
   
   
       6 . The method of  claim 5  including the step of providing winch means on said temporary buoyancy means for developing initial pre-tension in pre-installed tendons for anchoring said platform at the installation site.  
   
   
       7 . The method of  claim 5  including the step of rotating said temporary buoyancy means to a horizontal position prior to towing said platform to the installation site.  
   
   
       8 . The method of  claim 7  including the step of rotating said temporary buoyancy means to an upright position prior to ballasting down to the installation draft of said platform.  
   
   
       9 . The method of  claim 8  including the step of providing winch means on said temporary buoyancy means for developing initial pre-tension in pre-installed tendons for anchoring said platform at the installation site.  
   
   
       10 . The method of  claim 5  including the step of ballasting down said platform without using a heavy lift crane vessel to maintain the hydrostatic stability of said floating platform.