Method of and apparatus for mooring a floating structure

A tension mooring system for a floating platform comprising:

• anchor means positioned upon the bed of a body of water;
• permanent mooring lines secured to said anchor means and extending upwardly;
• buoyant means directly connected to the upper ends of said permanent mooring lines at a location below a zone of high corrosive, high oxygen content water adjacent the surface of the body of water said connection location further being below the lowest portion of the platform and said permanent mooring lines being dimensioned to maintain said buoyant means in a submerged posture below the zone of high oxygen content water and the lowest portion of the platform;
• sacrificial mooring lines connected to a submerged upper portion of said buoyant means and extending upwardly to the floating platform;
• means for connecting sacrificial mooring lines to the floating platform wherein the floating platform is located with respect to said anchor means by tension applied through said sacrificial mooring lines and said permanent mooring lines;
• and
• means operably connected to the platform for selectively replacing said sacrificial mooring lines between said buoyant means and the floating platform upon damage to said sacrificial lines, said means being operable to selectively replace said sacrificial mooring lines without releasing said permanent mooring lines from a secure direct connection to said submerged buoyant means.

A mooring system for a floating platform comprising:

• anchor means positioned upon the bed of a body of water;
• at least one permanent mooring line secured to said anchor means and extending upwardly;
• buoyant means directly connected to the upper end of said at least one permanent mooring line, said buoyant means being retained by said at least one permanent mooring line in a submerged posture and at a location below a zone of high corrosive, high oxygen content water adjacent the surface of the body of water and below the lowest portion of the floating platform;
• at least one sacrificial mooring line connected to the submerged buoyant means and extending upwardly to the floating platform;
• means for connecting said at least one sacrificial mooring line to the floating platform wherein the floating platform is located upon the body of water with respect to said anchor means by said at least one sacrificial mooring line, said buoyant means and said at least one permanent mooring line;
• and
• means operably connected to the floating platform for selectively replacing said at least one sacrificial mooring line between said buoyant means and the floating platform upon damage of said at least one sacrificial mooring line, said means being operable to selectively replace said at least one sacrificial mooring line without releasing said at least one permanent mooring line from a secure direct connection to said submerged buoyant means.

The method of establishing a mooring system for a floating platform including the steps of:

• setting an anchor on the bottom of a body of water with guide lines extending from said anchor to the water surface;
• lowering permanenet mooring lines on said guide lines to position the lower end of the permanent mooring lines in contact with the anchor and the upper end of the permanent mooring lines being supported by a buoy at a level below the water surface;
• securing the lower end of the permanent mooring lines to the anchor;
• securing replaceable mooring lines to said buoys;
• reaving each replaceable mooring line from a first storage reel aboard the floating platform to be moored by such mooring system through a tensioning apparatus, around a sheave secured to said buoy and back to a second reel aboard said floating platform;
• and
• in the event it is desired to replace said replaceable mooring line, paying out replaceable mooring line from the first storage reel and taking up replaceable mooring line on the second storage reel.

A tension mooring system for a floating platform comprising:

• anchor means positioned upon the bed of a body of water;
• permanent mooring lines secured to said anchor means and extending upwardly;
• buoyant means connected to the upper ends of said permanent mooring lines at a location below a zone of high corrosive, high oxygen content water adjacent the surface of the body of water said connection location further being below the lowest portion of the platform and said permanent mooring lines being dimensioned to maintain said buoyant means in a submerged posture below the zone of high oxygen content water and the lowest portion of the platform;
• sacrificial mooring lines connected to a submerged upper portion of said buoyant means and extending upwardly to the floating platform;
• means for connecting sacrificial mooring lines to the floating platform wherein the floating platform is located with respect to said anchor means by tension applied through said sacrificial mooring lines and said permanent mooring lines;
• and
• means operably connected to the platform for selectively replacing said sacrificial mooring lines between said buoyant means and the floating platform upon damage to said sacrificial lines, said means for selectively replacing includes
• a sheave secured to said buoyant means and a sacrificial mooring line extending from said floating platform downwardly around said sheave and back to said platform;
• and
• means for taking up one end of the sacrificial mooring line and paying out the other end thereof until the length of sacrificial mooring line extending between the floating platform and said buoyant means is replaced.