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EP-4065457-B1 - MOORING LINE CONNECTOR APPARATUS AND METHOD

EP4065457B1EP 4065457 B1EP4065457 B1EP 4065457B1EP-4065457-B1

Inventors

  • MEASON, Jonathan
  • MILLER, Calum
  • ANNAL, WILLIAM

Dates

Publication Date
20260513
Application Date
20201124

Claims (14)

  1. A pre-tensionable connector apparatus (50), comprising: a first connector assembly (100); a second connector assembly (200) for connection to the first connector assembly; a pre-tensioning arrangement (302) positioned in fixed relation to the second connector assembly, for applying a pre-tensioning force between the first and second connector assemblies; wherein the pre-tensioning arrangement is reconfigurable between a first configuration and a second configuration; a pull line (150) extending from the first connector assembly and adapted to be coupled to the pre-tensioning arrangement by coupling apparatus; and coupling apparatus for coupling the pull line to the pre-tensioning arrangement; wherein, when the first and second connector assemblies are engaged or proximal to one another, a portion of the pull line is positionable in relation to the pre-tensioning arrangement such that the pull line may be coupled thereto by the coupling apparatus; and wherein, when the pre-tensioning arrangement is coupled to the pull line by the coupling apparatus, and the pre-tensioning arrangement is in the second configuration the said-pre tensioning force is applied by the pre-tensioning arrangement between the first and second connector assemblies via the pull line; and characterized in that the pre-tensioning arrangement (302) is configured to be locked in place in the second configuration, to passively maintain the pre-tensioning force.
  2. The pre-tensionable connector apparatus (50) of claim 1, wherein the pre-tensioning force is applied by reconfiguring the pre-tensioning arrangement (302) from the first configuration to the second configuration.
  3. The pre-tensionable connector apparatus (50) of claim 1 or 2, configured for the coupling apparatus to be connected to the pre-tensioning arrangement (302) when the pre-tensioning arrangement is in the first configuration and wherein, when the pre-tensioning arrangement is coupled to the pull line (150) by the coupling apparatus, reconfiguring the pre-tensioning arrangement from the first configuration to the second configuration applies the said-pre tensioning force.
  4. The pre-tensionable connector apparatus (50) of claim 2 or 3, wherein the pre-tensioning arrangement (302) is extended in use to reconfigure the pre-tensioning arrangement from the first to the second configuration, optionally wherein the pre-tensioning arrangement is extended in use to apply the pre-tensioning force.
  5. The pre-tensionable connector apparatus (50) of any preceding claim, wherein pull line (150) extends to and terminates at a coupling portion (160), optionally wherein the pull line is flexible, optionally wherein the pull line comprises a length of cable or chain.
  6. The pre-tensionable connector apparatus (50) of claim 5, wherein the coupling apparatus comprises a latch pin (166) and the coupling portion (160) comprises a generally tubular latch pin aperture (164) extending from a first side to a second side through the coupling portion and sized to receive the latch pin and wherein, in use the pre-tensioning arrangement (302) may engage with the latch pin on the first and second sides of the coupling portion.
  7. The pre-tensionable connector apparatus (50) of claim 6, wherein the pre-tensioning arrangement (302) comprises first and second jacking plates (320a, 320b), moveable in relation to the second connector assembly (200) to engage with the respective ends of the latch pin (166) extending from the latch pin aperture (164), optionally wherein the first and second jacking plates are provided with receiving formations (324a, 324b) to engage with the ends of the latch pin.
  8. The pre-tensionable connector apparatus (50) of any preceding claim, wherein the connector apparatus further comprises a spacer structure extending between the second connector assembly (200) and the pre-tensioning arrangement (302), optionally wherein the spacer structure provides a pathway for pulling the pull line (150), in order to bring the first and second connector assemblies (100, 200) into engagement with one another in use.
  9. The pre-tensionable connector apparatus (50) of claim 8, wherein the spacer structure is a generally tubular structure or a moon pool through the hull of a floating vessel, optionally wherein the pre-tensioning arrangement (302) is attached to, or fixed proximal to, an upper end of the tubular structure or moon pool.
  10. A moon pool for a floating vessel, the moon pool comprising: a tubular structure having an upper and a lower end and defining a longitudinal axis; and connector apparatus according to any preceding claim.
  11. A method of connecting the pre-tensionable connection apparatus (50) according to any one of claims 1 to 9, comprising: bringing the first connector assembly (100) into engagement with the second connector assembly (200); reconfiguring the pre-tensioning arrangement (302) from the first configuration to the second configuration; and coupling the pull line (150) to the pre-tensioning arrangement; applying a pre-tensioning force between the first and second connector assemblies via the pre-tensioning arrangement, when the pre-tensioning arrangement is in the second configuration, wherein the pre-tensioning force is a residual force applied between the connector assemblies via the pull line to retain them in connection with one another; and passively maintaining the pre-tensioning arrangement in the second configuration.
  12. The method of claim 11, comprising coupling the pull line (150) to the pre-tensioning arrangement (302) when the pre-tensioning arrangement is in the first configuration; and reconfiguring the pre-tensioning arrangement from the first configuration to the second configuration to apply the pre-tensioning force.
  13. The method of claim 11, comprising: applying a first force to the pull line (150) between the first and second connector assemblies (100, 200), wherein the first force is equal to or greater than the pre-tensioning force; coupling the pre-tensioning arrangement (302) to the pull line; reconfiguring the pre-tensioning arrangement from the first to the second configuration; and releasing the first force, whereby the pre-tensioning force such that the pre-tensioning force between the first and second connector assemblies is maintained by the pre-tensioning arrangement, in the second configuration thereof, optionally wherein the first force is applied by a winch.
  14. The method of any one of claims 11 to 13, comprising pulling the pull line (150) to bring the first and second coupling assemblies (100, 200) into engagement with or into proximity to one another, optionally comprising pulling the pull line via a moon pool on a floating vessel.

Description

Field of the Invention The invention relates to an apparatus and method for connecting a mooring line to a floating structure, such as a floating renewable energy generating apparatus, in particular a tidal turbine or other water current power generating apparatus. Background to the Invention In offshore renewable energy industries, there is increasing focus on the use of semi-permanent floating structures, in preference over those anchored directly to the sea bed. Floating structures can be more quickly and cost effectively deployed, and can be readily towed to shore for decommissioning or repair or relocated to another tidal, wind resource. Floating structure need to be moored to the sea bed by mooring lines (typically chains, wires or the like). Typically, there is also a requirement to connect additional lines, such as electrical distribution cables, to the floating structure. WO 2009/141617 (Scotrenewables Marine Power Limited) describes a mooring connector with a "moon pool" (i.e. a bore extending through the deck and hull of the vessel), into which a buoyant frustoconical connector can be cooperatively received. The connector is latched into position around an annular channel on its outer surface, which enables rotation of the connector in relation to the vessel. This arrangement is of particular benefit in the context of floating tidal turbines which must be rotated end-to-end with each cycle of the tides. Where the turbine apparatus need not be rotated in this way, for example in use in a constantly flowing body of water such as a river or estuary, or where the turbine blades themselves can rotate in order to obviate the requirement to rotate the entire vessel, a rotatable connector such as described in WO 2009/141617 is not required. So-called "turret" systems are known for use in the oil and gas industry, which take the form of tubular housings extending through the vessel hull to the deck. However conventional systems are not optimised for the particular requirements of floating water current power generation, or the particular stresses transferred via to the mooring connectors of such apparatus by the flowing water acting on turbine blades. WO 2016/180866 (Single Buoy Moorings Inc.) describes a mooring like connector which has a rotatable guiding body around a central connector body. The connector body is pulled into a tubular housing and locked in place by a complex set of internal end external guide formations and pins, forming part of the guiding body and tubular housing. The connector is specifically adapted to minimise torque, by the provision both of a universal joint at the base of the connector body, and rotational independence between the guide formations and the connector body. Any axial play in the system is prevented only by the weight of the connector and mooring lines. Moreover, the concentric arrangement of guide formations, bearings and connector body takes up the substantial portion of the diameter of the housing. GB 2500904 (Sigma Offshore Limited) describes a similar mooring line connector, in which a male component is pulled into a tubular female component and latched into place by an array of hydraulic latch elements. Relative axial motion is restricted by the latches, but in order to provide a fail-safe, the latch elements are biased away from abutment with the male connector. US5356321 describes a mooring turret in which a spider buoy is pulled into engagement with the base of the turret 10. A tension connector includes hydraulic cylinders and driving bear locks. The tension connector is lowered into the turret and latched using the hydraulic cylinders and driving bear locks. WO 2006/037964 describes a riser inboarding system in which a floatation cannister is pulled into a lower housing of a connector, using a connector line, and retained by a locking mechanism. WO96/30253 A1 describes a mooring device in which a buoy is retained in a socket at the lower end of a shaft. A tensioning means 18 includes hydraulic jacks tighten a fastening cable that extends between the buoy and the tensioning means. Prior art systems of this type are not optimised for use in the field of tidal power generating apparatus, or similar applications in which comparatively extreme forces are applied between the moorings and the vessel during normal operation. Summary of the Invention According to a first aspect of the invention there is provided a pre-tensionable connector apparatus, comprising: a first connector assembly;a second connector assembly for connection to the first connector assembly;a pre-tensioning arrangement positioned in fixed relation to the second connector assembly, for applying a pre-tensioning force between the first and second connector assemblies; wherein the pre-tensioning arrangement is reconfigurable between a first configuration and a second configuration;a pull line extending from the first connector assembly and adapted to be coupled to the pre-tensioning arrangement