Release mechanism and method of use of same

A method for disconnecting mooring lines of a moored vessel, comprising the steps of:

• a) providing a release mechanism comprising:
• a main body comprising first and second mating sections disconnectable along a line of disconnection, an end of each section having openings to which sections of said mooring line can be attached, each of said first and second sections having a transverse inwardly extending flange adjacent the line of disconnection;
• one or more movable locking shoes having a locking portion bridging said flanges and line of disconnection, said locking shoes having opposed surfaces for engaging said flanges, said shoes locking said first and second sections together when said opposed surfaces thereof are maintained in contact with said flanges;
• each of said shoes having an inwardly curved rocker portion at one end thereof adapted to contact side walls of the main body when moved radially outwardly, the outward movement of said rocker portion causing the locking portion to move radially inwardly and disengage the opposed surfaces of said locking portion from said flanges to thereby permit disconnection of said body sections;
• a button comprising an exterior cam surface located adjacent said locking shoes and in a first position holding said locking portion of said locking shoes in contact with said flanges, said cam surface being adapted to contact and move said rocker portion radially outwardly and cause said locking portion of said locking shoes to move away from said flanges and thereby permit separation of said sections, when said cam surface is in a second position;
• a remotely operable acoustic internal assembly for moving said button between said first and said second positions, said internal assembly connected to said button by a shaft;
• and
• a mechanical means for moving said button from said first position to said second position, wherein said locking shoes can move to a second unlocked position and said first and second sections of said release mechanism can disconnect, said mechanical means operable by application of an external force to said mechanical means;
• wherein said mechanical means for moving said cam comprises:
• (i) a pair of trigger rods disposed on said main body and longitudinally movable thereon;
• (ii) a pair of trigger arms rotatably mounted on said main body, one end of each of said trigger arms positioned proximal said button, the other end of each of said trigger arms disposed proximal one end of said trigger rods, and (iii) whereby longitudinal movement of said trigger rods pushes one end of said trigger arm and rotates same into contact with said button, and whereby continued longitudinal movement of said trigger rods and said trigger arm moves said button to its second position wherein said locking shoes move to a second, unlatched position and said release mechanism disconnects;
• b) installing said release mechanism in a subsea position in a mooring line, said mooring line extending from a moored vessel to an anchor, said moored vessel comprising a winch adapted to pull in said mooring line to said moored vessel, said moored vessel further comprising a mooring line fairlead through which said mooring line runs;
• c) pulling in said mooring line until said trigger rods of said release mechanism are contacted by said fairlead, and continuing to pull said release mechanism until said trigger rods push on and rotate said trigger arms, and said trigger arms push said button to its second, unlocked position, in turn moving said locking shoes to their second, unlocked position;
• and
• d) pulling said first and said second sections of said release mechanism apart, thereby disconnecting said mooring line.

A method for disconnecting mooring lines of a moored vessel, comprising the steps of:

• a) providing a release mechanism comprising:
• a main body comprising first and second mating sections disconnectable along a line of disconnection, an end of each section having openings to which sections of said mooring line can be attached, each of said first and second sections having a transverse inwardly extending flange adjacent the line of disconnection;
• one or more movable locking shoes having a locking portion bridging said flanges and line of disconnection, said locking shoes having opposed surfaces for engaging said flanges, said shoes locking said first and second sections together when said opposed surfaces thereof are maintained in contact with said flanges;
• each of said shoes having an inwardly curved rocker portion at one end thereof adapted to contact side walls of the main body when moved radially outwardly, the outward movement of said rocker portion causing the locking portion to move radially inwardly and disengage the opposed surfaces of said locking portion from said flanges to thereby permit disconnection of said body sections;
• a button comprising an exterior cam surface located adjacent said locking shoes and in a first position holding said locking portion of said locking shoes in contact with said flanges, said cam surface being adapted to contact and move said rocker portion radially outwardly and cause said locking portion of said locking shoes to move away from said flanges and thereby permit separation of said sections, when said cam surface is in a second position;
• a remotely operable acoustic internal assembly for moving said button between said first and said second positions, said internal assembly connected to said button by a shaft;
• and
• a mechanical means for moving said button from said first position to said second position, wherein said locking shoes can move to a second unlocked position and said first and second sections of said release mechanism can disconnect, said mechanical means operable by application of an external force to said mechanical means;
• wherein said mechanical means for moving said cam comprises:
• (i) a pair of trigger rods disposed on said main body and longitudinally movable thereon;
• (ii) a pair of trigger arms rotatably mounted on said main body, one end of each of said trigger arms positioned proximal said button, the other end of each of said trigger arms disposed proximal one end of said trigger rods, and (iii) whereby longitudinal movement of said trigger rods pushes one end of said trigger arm and rotates same into contact with said button, and whereby continued longitudinal movement of said trigger rods and said trigger arms moves said button to its second position wherein said locking shoes move to a second, unlatched position and said release mechanism disconnects;
• b) installing said release mechanism in a subsea position in a mooring line, said mooring line extending from a moored vessel to an anchor;
• c) installing a trigger sleeve around said mooring line between said moored vessel and said release mechanism, with a line running from said trigger sleeve to an intervention vessel
• d) with said intervention vessel, pulling said trigger sleeve into contact with said trigger rods on said release mechanism, and continuing to pull said trigger sleeve until said trigger rods push on and rotate said trigger arms, and said trigger arms push said button to its second, unlocked position, in turn moving said locking shoes to their second, unlocked position;
• and
• d) pulling said first and said second sections of said release mechanism apart, thereby disconnecting said mooring line.

A mooring line release apparatus, comprising:

• a main body having first and second mating sections disconnectable along a line of disconnection, an end of each section adapted to attach a section of mooring line thereto, the main body comprising:
• an acoustically operable release mechanism adapted to disconnect said first and second mating sections;
• and
• a mechanically operable release mechanism adapted to disconnect said first and second mating sections by an external force applied to said main body without the use of a subsea remotely operated vehicle,
• whereby said acoustically operable release mechanism and said mechanically operable release mechanism are both disposed at least partially within said main body, and
• wherein disconnection of said first and second mating sections is along said line of disconnection, when either said acoustically operable release mechanism or said mechanically operable release mechanism is actuated.

A method, comprising the step of:

• a) positioning a mooring line release apparatus in the mooring line of a moored vessel, said apparatus comprising:
• a main body having first and second mating sections disconnectable along a line of disconnection, an end of each section adapted to attach a section of mooring line thereto, the main body comprising:
• an acoustically operable release mechanism adapted to disconnect said first and second mating sections;
• and
• a mechanically operable release mechanism adapted to disconnect said first and second mating sections by an external force applied to said main body without the use of a subsea remotely operated vehicle,
• whereby said acoustically operable release mechanism and said mechanically operable release mechanism are both disposed at least partially within said main body, and
• wherein disconnection of said first and second mating sections is along said line of disconnection, when either said acoustically operable release mechanism or said mechanically operable release mechanism is actuated.