Abstract: A releasable latch-type connector for a tension leg platform tether. A tether portion of the latch is provided with an annularly arranged set of shear lugs. The tether portion of the latch is adapted to be received within a generally cylindrical second portion of the latch. The second portion of the latch is also provided with an annularly arranged set of shear lugs. The two sets of shear lugs are arranged so that the tether portion of the latch may be inserted into the second portion of the latch and then rotated and lifted to cause the two sets of shear lugs to come into abutment, preventing further withdrawal of the tether portion of the latch. This connector is particularly well suited for securing the lower end of a tension leg platform tether to a foundation on the ocean bottom.

Abstract: A vibration-isolating apparatus for protecting equipment from excessive vibrations. The apparatus discloses an equipment-carrying frame attached by shock-absorbing members to a guide member. The guide member is loosely fastened in operational relationship wth a drillpipe or casing to permit movement of the apparatus. The apparatus is lowered along the drillpipe or casing by a cable or other locomotive means controlled from the surface. Vibration of the drillpipe created by ocean currents or waveloading forces causes the drillpipe to impact and vibrate the guide member of the apparatus. The shock-absorbing members protect equipment attached to the frame by attenuating the excessive vibrations induced by the drillpipe on the apparatus. Shock-absorbing members of varying stiffness can be substituted to attenuate the differing vibrational forces exerted by each particular drillpipe.

Abstract: A buoyancy system for a tension leg platform tether 10 or other element extending a significant vertical distance through a body of water. A series of bulkheads 25 divide the interior of the tether 10 into individual buoyancy cells 31. A central access tube 32 extends along the central axis of the tether 10, passing through a sealed penetration in each bulkhead 25. A series of cascade conduits 42 are provided the lower portion of each buoyancy cell 31 in fluid communication with the buoyancy cell 31 immediately above. A tool 82 is provided for injecting air into a selected buoyancy cell 31. As air is injected, water exists through the central access tube 32 until the buoyancy cell 32 is emptied of water, at which point air passes through the cascade conduit 42 into the adjacent upper buoyancy cell. The tool 82 can also be used to selectively flood individual buoyancy cells 31.

Abstract: A fairing for elongated elements is disclosed for reducing current-induced stresses on the elongated element. The fairing is made as a stream-lined shaped body that has a nose portion in which the elongated element is accommodated and a tail portion. The body has a bearing connected to it to provide bearing engagement with the elongated element. A biasing device interconnected with the the bearing accommodates variations in the outer surface of the elongated element to maintain the fairing's longitudinal axis substantially parallel to the longitudinal axis of the elongated element as the fairing rotates around the elongated element. The fairing is particularly adapted for mounting on a marine drilling riser having flotation modules.