Abstract: In a system for mooring offshore drilling units, a first mooring assembles installed at a first drilling venue, after which the mobile offshore drilling unit is moored by connection to the mooring lines. A second mooring assembly is installed at a second drilling venue while drilling operations are carried out at the first drilling venue. In this manner the mobile offshore drilling unit can be relocated between successive drilling venues with minimum down time. Less than complete mooring assemblies can be used to temporarily secure the mobile offshore drilling unit.

Abstract: In a system for mooring offshore drilling units, a first mooring assembly is installed at a first drilling venue, after which the mobile offshore drilling unit is moored by connection to the mooring lines. A second mooring assembly is installed at a second drilling venue while drilling operations are carried out at the first drilling venue. In this manner the mobile offshore drilling unit can be relocated between successive drilling venues with minimum down time. Less than complete mooring assemblies can be used to temporarily secure the mobile offshore drilling unit.

Abstract: In a system for mooring offshore drilling units, a first mooring assembles installed at a first drilling venue, after which the mobile offshore drilling unit is moored by connection to the mooring lines. A second mooring assembly is installed at a second drilling venue while drilling operations are carried out at the first drilling venue. In this manner the mobile offshore drilling unit can be relocated between successive drilling venues with minimum down time. Less than complete mooring assemblies can be used to temporarily secure the mobile offshore drilling unit.

Abstract: An anchor installation vessel transports anchors and mooring lines to an installation site and installs the anchors at diametrically opposed points in an anchor array. Following installation the mooring lines are directed to the vessel from opposite sides and are preloaded using winches mounted on the vessel.

Abstract: In a method of and apparatus for anchor installation, a plate anchor is mounted at the bottom of a suction follower comprising a hollow cylinder having an open lower insertion end and a closable upper suspension end. The suction follower and the anchor secured thereto are engaged with the sea floor, whereupon water is pumped out of the suction follower causing the suction follower and the anchor to penetrate into the sea floor to a predetermined depth. The anchor is then disengaged from the suction follower, whereupon water is pumped into the suction follower to disengage the suction follower from the sea floor for recovery to the surface, leaving the anchor embedded in the sea floor.

Abstract: A taut leg bow mooring system includes an anchor positionable on the floor of the sea. A riser line is normally secured to and extends upwardly from the anchor, and a submerged buoy is secured to the end of the riser line remote from the anchor. A line extends upwardly from the submerged buoy to a surface buoy. A mooring line is pivotally connected in the line extending from the submerged buoy to the surface buoy.

Abstract: A taut leg bow mooring system (40) includes an anchor (42) positionable on the floor of the sea. A riser line (44) secured to and extending upwardly from the anchor, and a submerged buoy (46) secured to the end of the riser line from the anchor. The ratio of the net buoyancy of the surface buoy to the buoyancy of the submerged buoy is at least 2 to 1. A buoyant connector line (50) is secured to and extends upwardly from the submerged buoy. A surface buoy (52) is secured to the end of the connector line remote from the submerged buoy, and a hawser (56) is secured to and extends from the surface buoy.