GB2493935A - Buoyant structure with rapidly releasable seabed fixing arrangement - Google Patents

Buoyant structure with rapidly releasable seabed fixing arrangement Download PDF

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Publication number
GB2493935A
GB2493935A GB1114453.2A GB201114453A GB2493935A GB 2493935 A GB2493935 A GB 2493935A GB 201114453 A GB201114453 A GB 201114453A GB 2493935 A GB2493935 A GB 2493935A
Authority
GB
United Kingdom
Prior art keywords
releasable
buoyant structure
gravity base
buoyant
taut
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB1114453.2A
Other versions
GB201114453D0 (en
Inventor
David Bone
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tamacrest Ltd
Original Assignee
Tamacrest Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tamacrest Ltd filed Critical Tamacrest Ltd
Priority to GB1114453.2A priority Critical patent/GB2493935A/en
Publication of GB201114453D0 publication Critical patent/GB201114453D0/en
Publication of GB2493935A publication Critical patent/GB2493935A/en
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
    • B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
    • B63B1/04—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull
    • B63B1/048—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull with hull extending principally vertically
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
    • B63B21/24—Anchors
    • B63B21/26—Anchors securing to bed
    • B63B21/29—Anchors securing to bed by weight, e.g. flukeless weight anchors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
    • B63B21/50—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers
    • B63B21/502—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers by means of tension legs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B22/00—Buoys
    • B63B22/04—Fixations or other anchoring arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03D—WIND MOTORS
    • F03D13/00—Assembly, mounting or commissioning of wind motors; Arrangements specially adapted for transporting wind motor components
    • F03D13/20—Arrangements for mounting or supporting wind motors; Masts or towers for wind motors
    • F03D13/25—Arrangements for mounting or supporting wind motors; Masts or towers for wind motors specially adapted for offshore installation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
    • B63B1/02—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement
    • B63B1/04—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull
    • B63B2001/044—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving lift mainly from water displacement with single hull with a small waterline area compared to total displacement, e.g. of semi-submersible type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00—Components
    • F05B2240/90—Mounting on supporting structures or systems
    • F05B2240/93—Mounting on supporting structures or systems on a structure floating on a liquid surface
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00—Components
    • F05B2240/90—Mounting on supporting structures or systems
    • F05B2240/95—Mounting on supporting structures or systems offshore
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/72—Wind turbines with rotation axis in wind direction
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/727—Offshore wind turbines

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Revetment (AREA)

Abstract

A taut moored buoyant structure seabed fixing arrangement comprises a water surface piercing buoyant structure 1, a gravity base structure 2, flexible connectors 3, and a releasable locking mechanism that allows rapid release of the buoyant structure from a moored position. The flexible connectors attach the buoyant structure to the gravity base structure such that that the flexible connectors remain in tension in the moored position and a released position. A foundation template 4 may be fixed into and below the seabed and the gravity base structure may be fixed to the foundation template by releasable keys 7. If mobile hazards approach, the buoyant structure can be rapidly removed to a safe distance. When sufficiently deballasted with the keys released the buoyancy forces lift the gravity base structure from the foundation template with the flexible connectors remaining in tension.

Description

RELEASABLE BUOYANT STRUCTURE
This invention relates to offshore taut moored buoyant structures, generally for use in energy industries where there is a power, support, or control requirement, or for surveillance.
Currently, taut moored structures are anchored to a gravity base on the seabed and have a buoyant structure piercing the water surface and attached to the gravity base structure using flexible mooring lines (tethers). The tethers are pre-tensioned and maintained in a taut condition from the buoyancy of the buoyant structure which is pulled down appropriate'y lower in the water than its natural floating position. This usually requires at least eight tethers and a large pre-tension force.
Also, the gravity base structure must provide sufficient downward force to prevent sliding or overturning motions, and thus is necessarily very heavy or / and requires additional piling to the seabed. Consequently, in order to re-locate or temporarily move the gravity base structure a considerable effort is needed, requiring the use of multiple vessels and taking a considerable time. In the event of a large uncontrollable hazard for example an ice berg approaching the buoyant structure, it would be necessary to move the structure quickly and allow the hazard to pass before repositioning the structure in its initial location. Similar problems are encountered if it is attempted to move the buoyant structure by itself and leave the gravity base structure in situ for subsequent re-connection. Considerable force would be required to disconnect the buoyant structure and tethers from the gravity base, and.vessels would be required. Also the buoyant structure would need additional support from further vessels, and the trailing tethers would become prone to damage.
We have now devised a means of alleviating the above problems. The invention provides a quick release method and equipment for a taut moored buoyant structure for avoidance of large mobile hazards.
According to the present invention there is provided a taut moored releasable buoyant structure comprising a water surface piercing buoyant structure, a gravity base structure, flexible connectors, and a releasable locking mechanism that allows rapid release of the buoyant structure from its installed operational position, arranged such that the flexible connectors attach the buoyant structure to the gravity base structure and such that the connectors remain in tension during normal operation, with said gravity base structure being secured to the seabed by gravity, a ballast weight, or including a connection means.
In one embodiment of the invention the connection means for securing the gravity base to the seabed is formed using a foundation template which is itself secured to the seabed by gravity or by a template to seabed connection means. The foundation template is inserted into and below the surrounding seabed and can provide protection for other equipment located underneath e.g. wellheads and trees. The template to seabed connection means can be suction piles, ordinary piles, a large ballast weight or combination thereof In one embodiment the foundation template has guidance devices located on its top sides for aid of installation of the gravity base structure. These can be metal frames that form a slope inwards towards the template so as to slide the gravity base structure in the desired direction.
In one embodiment of the invention the releasable locking mechanism is formed using a lock and key device in combination with the foundation template. In this case the gravity base structure has a recess in its side for location of a large metal key, and the foundation template has a large metal block retaining the key through which the key can travel into the gravity base recess to lock the two together. On removal this process is reversible.
In another embodiment the releasable locking mechanism is formed using a lock and key device incorporated into the gravity base. In this case a connection frame forms part of the gravity base and is attached to and anchors the bottom ends of the tethers. The connection frame is releasably attached to the gravity base using the lock and key device. In this case the lock and key device can consist of a recess in the gravity base or the connection frame and a key in the connection frame or gravity base. There can be more than one key and more than one recess, and a recess could be horizontal or vertical. The key can have a shaped end that can be twisted into a vertical recess to resist upward motion. In this embodiment the top of the gravity base can have guidance devices located to aid installation of the connection frame.
The releasable locking mechanism can be operated remotely using a hydraulic actuator.
In one embodiment the taut moored buoyant structure is an unmanned facility with controls that can be remotely accessed and monitored, and with a hull that has a water surface piercing tubular section. The hull provides housing under the water surface for location of fluids, power sources, control means, production equipment, or combinations thereof.
In another embodiment the taut moored buoyant structure is an unmanned facility with a hull that supports a telescopically extendable shaft, with excess buoyancy (used to ensure taut mooring) provided by the hull or additionally provided by buoyancy devices attached to the hull.
In one embodiment a power source is provided by a wind turbine. The wind turbine can be located on the taut moored buoyant structure.
Alternatively, a power source is provided by diesel generators, or by gas turbines, by gas engines, or by a combination.
In one embodiment a central pull down connector is included for temporary connection between the buoyant structure and the gravity base structure. This can be used to aid installation and removal.
Also included in this invention is a method of removal and re-installation of the buoyant structure. In order to initiate removal (in the event that a hazard is approaching) the locking mechanism is activated so that the key is released from the recessed retaining lock. In the case where a foundation template is used this causes the gravity base structure to be unlocked from the foundation template. The gravity base structure is then de-ballasted until it lifts clear of the template and nearby surrounding seabed formations. The buoyant structure including gravity base structure is attached to tugs and towed to a safe location until the hazard has passed. In the case where a connection frame is used then the key release causes the connection frame to be unlocked from the gravity base. The buoy is ballasted (prior to key release) sufficiently to maintain a suitable draft in the water, then after key release the connection frame is de-ballasted if necessary until it gains clearance from the top of the gravity base and surroundings. The buoyant structure including the connection frame is then attached to tugs and towed to a safe location until the hazard has passed. Towing can be aided by outboard motors attached to the buoyant structure. The re-installation procedure is a reversal of the removal.
A specific embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings in which: -Figure 1 shows a general arrangement view of a releasable buoyant structure in situ.
Figure 2 shows a section view through a gravity base structure.
Figure 3 shows a perspective view of a foundation and installation template.
Figure 4 shows a side elevation view of a releasable buoyant structure during temporary removal for avoidance of a hazard.
Referring to the drawings, there is shown a releasable buoyant structure consisting of a taut moored buoyant structure 1, a gravity base structure 2, spiral strand wire tethers 3, a foundation template 4, foundation piles 5, locking blocks 6, releasable keys 7 (only one shown), and a temporary installation tether 10.
The gravity base structure 2 has built in recesses S (Figure 2, only one shown) for locating and locking the releasable keys 7.
The foundation template 4 has guidance frames 9 (Figure 3) located on its topsides in order to aid installation of the gravity base structure 2.
The taut moored buoyant structure 1 is an unmanned facility with controls that can be remotely accessed and monitored. There is a radio / satellite link attached at the top of the buoyant structure 1 well above the water splash zone. Exhausts for power equipment exit the buoyant structure I above the splash zone. Fuel is stored in the buoyant structure 1 and is replenished via umbilical. Said buoyant structure 1 consists of two tubular sections, one being a larger diameter storage chamber. Conical sections are used at the intersections of the tubulars and at the bottom of the structure, in order to reduce wave forces. The larger diameter chamber is used to store power-generating equipment needed for the control, monitoring and power systems. This chamber is located below the water surface at a level designed to avoid large forces from wave action. The upper surface piercing tubular section is small enough to minimise wave forces but large enough to allow access for maintenance.
The lower conical section is small enough to minimise wave forces, but large enough to allow storage of a quantity of fuel or ballast material. The quantity of ballast material stored can be adjusted to suit loealised wave conditions in order to stabilise the buoyant structure I motions. The size of the tubular sections is designed to provide adequate buoyancy to maintain tension in the flexible connectors (providing the taut mooring) and dynamic stability during adverse weather conditions. Thus the structure 1 can be adjusted to suit different locations with differing wave climates.
When in situ the gravity base structure 2 has sufficient weight and ballast to resist uplift and overturning forces and to hold it in position on top of the foundation template 4. However, it is also locked to the foundation template 4 as shown. The locking mechanism allows the gravity base structure 2 to be held in position whilst de-ballasted prior to quick release operations. The foundation template 4 is secured to the seabed using piles 5. The buoyant structure I is pulled down in the water below its natural floating position and is connected to the gravity base structure with eight wire tethers 3. The locking blocks 6 are attached rigidly or formed as a part of the foundation template 4. Each releasable key 7 is fixed between a locking block 6 and a gravity base recess 8 thus locking the gravity base 2 to the foundation template 4.
Each releasable key 7 is operated by a hydraulic actuator which causes the key 7 to disengage with the recess 8 by moving outwards. Each key 7 is spring loaded and failure of the hydraulic actuator would result in a key 7 being released i.e. not locked. This is so that disconnection of the gravity base structure 2 from the template 4 is zdways possible in the event of actuator failure.
When a hazard warning is given the release system is put into operation. The gravity base structure 2 is de-ballasted to the extent that it would lift off of the foundation template 4 if not locked to it. De-ballasting is achieved remotely using signals sent to control hydraulic valves and pipes connected to the gravity base structure 2. Control signals are sent from a remote location to a receiver positioned on the buoyant structure 1. Tug vessels are deployed at the same time in order to tie tow lines to the buoyant structure 1. Then the releasable keys 7 are released by hydraulic actuation. The gravity base structure 2 then lifts clear of the seabed and surrounding slopes, also raising the buoyant structure 1 higher in the water. The buoyant structure I including gravity base structure 2 can then be towed away from the path of the hazard, Once the hazard has passed the gravity base structure 2 and buoyant structure 1 can be re-located back onto the foundation template 4. To achieve this a ballast operation is required after the gravity base structure is hovered above the foundation template 4. The guides 9 aid re-installation by directing the lowered gravity base structure onto the foundation template 4.
Then the keys 7 are re-set to the locked position.

Claims (1)

  1. <claim-text>CLAIMSI. A taut moored releasable buoyant structure comprising a water surface piercing buoyant structure, a gravity base structure, flexible connectors, and a releasable locking mechanism that allows rapid release of the buoyant structure from its installed position, arranged such that the flexible connectors attach the buoyant structure to the gravity base structure and such that the connectors remain in tension during normal operation, with said gravity base structure being secured to the seabed by gravity, a ballast weight, or including a connection means.</claim-text> <claim-text>2. A taut moored releasable buoyant structure as claimed in Claim I, wherein the connection means for securing the gravity base to the seabed is formed using a foundation template, said template being secured to the seabed by gravity or by a template to seabed connection means.</claim-text> <claim-text>3. A taut moored releasable buoyant structure as claimed in Claim 2, wherein the foundation template is inserted into and below the surrounding seabed.</claim-text> <claim-text>4. A taut moored releasable buoyant structure as claimed in Claim 2 or Claim 3, wherein the foundation template provides protection for other equipment located underneath.</claim-text> <claim-text>5. A taut moored releasable buoyant structure as claimed in any of claims 2 to 4, wherein the template to seabed connection means is formed using suction piles, ordinary piles, a large ballast weight or combination thereof 6. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein the releasable locking mechanism is formed using a lock and key device.7. A taut moored releasable buoyant structure as claimed in Claim 2, wherein the releasable locking mechanism is characterized in that the gravity base structure has a recess in its side for location of a large metal key, and the foundation template has a large metal block retaining the key through which the key can travel into the gravity base recess to lock the two together in a reversible operation.8. A taut moored releasable buoyant structure as c[aimed in Claim I, wherein the top of the gravity base structure incorporates a connection frame releasably attached by a lock and key device to form the releasable locking mechanism, said frame provides the bottom end attachment for the flexible connectors, said lock and key device consisting of a recess in the gravity base and a key in the connection frame or vice versa.9. A taut moored releasable buoyant structure as claimed in Claim 8, wherein the key has a shaped end that can be twisted into the recess to resist upward motion.10. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein the releasable locking mechanism can be operated remotely using a hydraulic actuator.1. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein the taut moored buoyant structure is an unmanned facility with controls that can be remotely accessed and monitored, and with a hull that has a water surface piercing tubular section.12. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein the taut moored buoyant structure has a hull providing housing under the water surface for location of fluids, power sources, control means, production equipment, or combinations thereof 13. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein the taut moored buoyant structure is an unmanned facility with a hull that supports a telescopically extendable shaft, with excess buoyancy (used to ensure taut mooring) provided by the hull or additionally provided by buoyancy devices attached to the hull.14. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein a power source is provided by a wind turbine.15. A taut moored releasable buoyant structure as claimed in Claim 14, wherein a wind turbine is located on the taut moored buoyant structure.16. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein a power source is provided by diesel generators, or by gas turbines, by gas engines, or by a combination.17. A taut moored releasable buoyant structure as claimed in Claim 2, wherein the foundation template has guidance devices located on its top sides for aid of installation of the gravity base structure.18. A taut moored releasable buoyant structure as claimed in CLaim 17, wherein the guidance devices are metal frames that form a slope inwards towards the template so as to slide the gravity base structure in the desired direction during installation.19. A taut moored releasable buoyant structure as claimed in any preceding claim, wherein a central pull down connector is included for temporary connection between the buoyant structure and the gravity base structure to aid installation and removal.20. A taut moored releasable buoyant structure substantially as herein described and illustrated in the accompanying drawings.21. A method of removal and re-installation of a taut moored releasable buoyant structure comprising a water surface piercing buoyant structure, a gravity base structure, flexible connectors, and a releasable locking mechanism that allows rapid release of the buoyant structure from its installed position, arranged such that the flexible connectors attach the buoyant structure to the gravity base structure such that the connectors remain in tension during normal operation, with said gravity base structure being secured to the seabed by connection means to a foundation template, said template being secured to the seabed by gravity or by a template to seabed connection means, said removal method being to activate the locking mechanism so that the gravity base structure is unlockçd from the foundation template, to dc-ballast the gravity base structure until it has sufficient uplift force to lift clear of the template and nearby surrounding seabed formations, to attach the buoyant structure to tugs, and then to tow to a safe location until any hazard has passed, the re-installation method being a reversal of the removal, 22. A method of removal and re-installation of a taut moored releasable buoyant structure comprising a water surface piercing buoyant structure, a gravity base structure, flexible connectors, and a releasable locking mechanism that allows rapid release of the buoyant structure from its installed position, arranged such that the flexible connectors attach the buoyant structure to the gravity base structure such that the connectors remain in tension during normal operation, with said gravity base structure being secured to the seabed by gravity, a ballast weight, or including a connection means, with the top of the gravity base structure incorporating a connection frame releasably attached by a lock and key device, said frame providing the bottom end connection for the flexible connectors, said removal method being to ballast the buoyant structure to reduce the force in the flexible connectors and attain a suitable draft in the water for stability, to activate the locking mechanism so that the connection frame is unlocked from the gravity base structure, to de-ballast the connection frame if necessary until it is lifted clear of the gravity base structure and nearby surrounding seabed formations, to attach the buoyant structure to tugs, and then to tow to a safe location until any hazard has passed, the re-installation method being a reversal of the removal.23. A method of removal and re-installation of a taut moored releasable buoyant structure as claimed in Claim 21 or Claim 22, wherein de-ballasting is achieved remotely by signals sent to control installed hydraulic valves and pipes.24. A method of removal and re-installation of a taut moored releasable buoyant structure as claimed in Claim 21 or Claim 22, wherein outboard motors are attached to the buoyant structure to facilitate or aid rapid removal.25. A method of removal and re-installation of a taut moored releasable buoyant structure, the method being substantially as herein described and illustrated in the accompanying drawings.</claim-text>
GB1114453.2A 2011-08-22 2011-08-22 Buoyant structure with rapidly releasable seabed fixing arrangement Withdrawn GB2493935A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1114453.2A GB2493935A (en) 2011-08-22 2011-08-22 Buoyant structure with rapidly releasable seabed fixing arrangement

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Application Number Priority Date Filing Date Title
GB1114453.2A GB2493935A (en) 2011-08-22 2011-08-22 Buoyant structure with rapidly releasable seabed fixing arrangement

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GB201114453D0 GB201114453D0 (en) 2011-10-05
GB2493935A true GB2493935A (en) 2013-02-27

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016177783A1 (en) * 2015-05-04 2016-11-10 Gicon Windpower Ip Gmbh Buoyant heavy weight anchor for anchoring a supporting structure floating in the open sea bearing a wind turbine, service station, or converter station
EP3153399A4 (en) * 2014-05-27 2018-05-30 Esteyco S.A.P. Floating substructure for a wind generator and method of installing same
CN116353796A (en) * 2023-04-19 2023-06-30 广东海洋大学 Floating self-rescue device under extreme typhoons of offshore platform

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1510425A (en) * 1975-08-11 1978-05-10 Texaco Development Corp Tension leg platform with quick release mechanism
GB2173466A (en) * 1985-03-27 1986-10-15 Shell Int Research Tension leg platform anchoring method and apparatus
GB2388820A (en) * 2002-05-03 2003-11-26 Ocean Technologies Ltd Remote subsea wellhead power support system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1510425A (en) * 1975-08-11 1978-05-10 Texaco Development Corp Tension leg platform with quick release mechanism
GB2173466A (en) * 1985-03-27 1986-10-15 Shell Int Research Tension leg platform anchoring method and apparatus
GB2388820A (en) * 2002-05-03 2003-11-26 Ocean Technologies Ltd Remote subsea wellhead power support system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3153399A4 (en) * 2014-05-27 2018-05-30 Esteyco S.A.P. Floating substructure for a wind generator and method of installing same
WO2016177783A1 (en) * 2015-05-04 2016-11-10 Gicon Windpower Ip Gmbh Buoyant heavy weight anchor for anchoring a supporting structure floating in the open sea bearing a wind turbine, service station, or converter station
CN116353796A (en) * 2023-04-19 2023-06-30 广东海洋大学 Floating self-rescue device under extreme typhoons of offshore platform
CN116353796B (en) * 2023-04-19 2024-05-31 广东海洋大学 Floating self-rescue device under extreme typhoons of offshore platform

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Publication number Publication date
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