Subsea dynamic load absorber

A subsea load absorber system arranged to act between relatively-movable subsea bodies, the system comprising a load absorber on one of the subsea bodies and an actuating member on another of the subsea bodies, wherein:

• the actuating member is cooperable with the load absorber to define an actuating chamber of variable volume that is flooded with water when the system is submerged in use;
• the load absorber comprises a hollow structure that defines an internal flow path for water, communicating with the actuating chamber;
• a flow restrictor acting on the flow path is positioned to restrict an outward flow of water along the flow path from the actuating chamber in use, which outward flow is caused by relative convergent movement between the actuating member and the load absorber that reduces the volume of the actuating chamber;
• and
• the flow restrictor comprises a shuttle element that is arranged to restrict the flow path and is movably mounted to the structure for automatic movement relative to the structure from a first state to a second state in response to an increase in water pressure in the actuating chamber, the shuttle element in the first state effecting greater restriction of outward flow along the flow path and in the second state effecting lesser restriction of outward flow along the flow path, the shuttle element being mounted for progressive movement from the first state to the second state as the water pressure in the actuating chamber progressively increases, so as to effect progressively less resistance to the outward flow, thereby dampening the relative movement to a progressively lesser degree.

A submersible or subsea body comprising:

• the submersible or subsea body being fitted with at least one load absorber or with a subsea load absorber system wherein:
• the at least one load absorber for dampening relative movement between subsea bodies, which load absorber is cooperable in use when on one of the subsea bodies with an actuating member on another of the subsea bodies, and the at least one load absorber for dampening comprises:
• a hollow structure that defines an internal flow path for water, communicating with a proximal opening;
• and
• a flow restrictor acting on the flow path that is positioned to restrict a distal flow of water along the flow path from the proximal opening in use, which distal flow is caused by relative convergent movement between the actuating member and the load absorber;
• wherein the flow restrictor comprises a shuttle element that is arranged to restrict the flow path and is movably mounted to the structure for automatic movement relative to the structure from a first state to a second state in response to an increase in water pressure at the proximal opening, the shuttle element in the first state effecting greater restriction of the distal flow along the flow path and in the second state effecting lesser restriction of the distal flow along the flow path, the shuttle element being mounted for progressive movement from the first state to the second state as the water pressure at the proximal opening progressively increases, so as to effect progressively less resistance to the distal flow, thereby dampening the relative movement to a progressively lesser degree;
• or
• the subsea load absorber system is arranged to act between relatively-movable subsea bodies, the subsea load absorber system comprises:
• a load absorber on one of the subsea bodies and an actuating member on another of the subsea bodies, wherein:
• the actuating member is cooperable with the load absorber to define an actuating chamber of variable volume that is flooded with water when the system is submerged in use;
• the load absorber comprises a hollow structure that defines an internal flow path for water, communicating with the actuating chamber;
• a flow restrictor acting on the flow path is positioned to restrict an outward flow of water along the flow path from the actuating chamber in use, which outward flow is caused by relative convergent movement between the actuating member and the load absorber that reduces the volume of the actuating chamber;
• and
• the flow restrictor comprises a shuttle element that is arranged to restrict the flow path and is movably mounted to the structure for automatic movement relative to the structure from a first state to a second state in response to an increase in water pressure in the actuating chamber, the shuttle element in the first state effecting greater restriction of outward flow along the flow path and in the second state effecting lesser restriction of outward flow along the flow path, the shuttle element being mounted for progressive movement from the first state to the second state as the water pressure in the actuating chamber progressively increases, so as to effect progressively less resistance to the outward flow, thereby dampening the relative movement to a progressively lesser degree.

A vessel comprising:

• a launch and recovery system having a cursor or a landing platform, the cursor or the landing platform being fitted with at least one load absorber or with a subsea load absorber system wherein
• the at least one load absorber for dampening relative movement between subsea bodies, which load absorber is cooperable in use when on one of the subsea bodies with an actuating member on another of the subsea bodies, and the at least one load absorber for dampening comprises:
• a hollow structure that defines an internal flow path for water, communicating with a proximal opening;
• and
• a flow restrictor acting on the flow path that is positioned to restrict a distal flow of water along the flow path from the proximal opening in use, which distal flow is caused by relative convergent movement between the actuating member and the load absorber;
• wherein the flow restrictor comprises a shuttle element that is arranged to restrict the flow path and is movably mounted to the structure for automatic movement relative to the structure from a first state to a second state in response to an increase in water pressure at the proximal opening, the shuttle element in the first state effecting greater restriction of the distal flow along the flow path and in the second state effecting lesser restriction of the distal flow along the flow path, the shuttle element being mounted for progressive movement from the first state to the second state as the water pressure at the proximal opening progressively increases, so as to effect progressively less resistance to the distal flow, thereby dampening the relative movement to a progressively lesser degree;
• or
• the subsea load absorber system is arranged to act between relatively-movable subsea bodies, the subsea load absorber system comprises:
• a load absorber on one of the subsea bodies and an actuating member on another of the subsea bodies, wherein:
• the actuating member is cooperable with the load absorber to define an actuating chamber of variable volume that is flooded with water when the system is submerged in use;
• the load absorber comprises a hollow structure that defines an internal flow path for water, communicating with the actuating chamber;
• a flow restrictor acting on the flow path is positioned to restrict an outward flow of water along the flow path from the actuating chamber in use, which outward flow is caused by relative convergent movement between the actuating member and the load absorber that reduces the volume of the actuating chamber;
• and
• the flow restrictor comprises a shuttle element that is arranged to restrict the flow path and is movably mounted to the structure for automatic movement relative to the structure from a first state to a second state in response to an increase in water pressure in the actuating chamber, the shuttle element in the first state effecting greater restriction of outward flow along the flow path and in the second state effecting lesser restriction of outward flow along the flow path, the shuttle element being mounted for progressive movement from the first state to the second state as the water pressure in the actuating chamber progressively increases, so as to effect progressively less resistance to the outward flow, thereby dampening the relative movement to a progressively lesser degree.