CONNECTOR DEVICE AND METHOD FOR LAYING ROPE

Description

Field of the Invention

[0001] 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

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] 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

[0012] 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 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 wherein the pre-tensioning arrangement is configured to be locked in place in the second configuration, to passively maintain the pre-tensioning force.

[0013] In use to connect the first and second connector assemblies, once the first connector assembly is engaged with the second connector assembly (or at least proximal thereto), a portion of the pull line is coupled to the pre-tensioning arrangement, typically with the pull line taut, and the pre-tensioning arrangement reconfigured such that the pre-tensioning force is applied.

[0014] The pre-tensioning apparatus provides for efficient connection between the first and second connector assemblies, by pulling the pull line, and the application of a pre-tensioning force to retain the connection. 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. The pre-tensioning force prevents movement between the first and second connector assemblies, in use. For example, the first connector assembly may be connected in use to a mooring line, or other apparatus prone to applying forces to the first connector assembly which act to disengage the first connector assembly from the second connector assembly, or cause movement therebetween. Any such relative movement, which might otherwise cause damage or wear to the connector assembly or the structures associated therewith (e.g. a floating vessel) may be reduced or eliminated by applying a pre-tensioning force between the first and second connector assemblies. The pre-tensioning force and any additional loads applied to the first connector assembly are also distributed via the pull line to the pre-tensioning arrangement. The structural requirements for receiving such forces can be located away from the connector assemblies themselves. This design flexibility may be of particular benefit in floating applications, to avoid engineering compromises for example in hull design.

[0015] The pre-tensioning force may be applied by reconfiguring the pre-tensioning arrangement from the first configuration to the second configuration. In some embodiments, a first force between the first and second connector assemblies is applied to the pull line equal to or in excess of the pre-tensioning force, the pre-tensioning arrangement reconfigured from the first to the second configuration and the first force released, 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.

[0016] The connector apparatus may be configured for the coupling apparatus to be connected to the pre-tensioning arrangement when the pre-tensioning arrangement is in the first configuration and wherein, when the pre-tensioning arrangement is coupled to the pull line by the coupling apparatus, reconfiguring the pre-tensioning arrangement from the first configuration to the second configuration applies the said-pre tensioning force.

[0017] By reconfiguring, herein we refer to at least moving one or more parts of the pre-tensioning arrangement. Reconfiguring may include adding one or more components to the pre-tensioning arrangement, such as a retainer or spacer as discussed below.

[0018] The pre-tensioning arrangement may be extended from the first configuration to the second configuration, in some embodiments to apply the pre-tensioning force. The pre-tensioning arrangement may be contracted or otherwise reconfigured, in some embodiments in order to apply the pre-tensioning force.

[0019] The pull line may comprise a coupling portion. A coupling portion may for example comprise an aperture or other latching formation therein.

[0020] The coupling apparatus may be adapted to engage with the coupling portion. The coupling apparatus may for example comprise extendable latches, a clamp, or the like.

[0021] Any suitable latching arrangements may be used, such as one or more collars, plates or pin adapted to be received in a recess, channel, lip or other suitable formation on the coupling portion.

[0022] The coupling apparatus may comprise a latch pin; and the coupling portion may comprise a latch pin aperture extending from a first side to a second side thereof and sized to receive the latch pin.

[0023] The pre-tensioning arrangement may engage with the latch pin on the first and second sides of the coupling portion of the pull line.

[0024] The pull line coupling portion may be a part of the pull line, such as a chain link, or a terminal chain link wherein the pull line is a chain.

[0025] The pull line may extend to and terminate at the coupling portion.

[0026] The coupling portion may be a separate component. Accordingly, the it may be sized independently of the pull line, and thus any suitable dimensions for the latching apparatus may selected. For example, the width between the first and second sides, and any suitable diameter of latch pin and latch pin aperture, may be selected independently of the dimensions of the pull-line.

[0027] In use the pre-tensioning force will be transmitted to the latch pin and distributed across the portions of the latch pin which engage with the pre-tensioning arrangement. The latch pin and connector portion may therefore be dimensioned so as to distribute these forces more widely than has previously been possible.

[0028] For example, conventional pre-tensioning or latching is achieved by introducing a pin through a chain link, or a loop in a pull line. In such arrangements, the forces are typically applied via an interface between two generally rounded bodies and so stresses are relatively focussed. Moreover, the dimensions of the latch pin may be limited by the size of the chain links.

[0029] The latch pin aperture may be generally tubular. A tubular aperture may transmit the pre-tensioning force along a length of the latch pin, in use.

[0030] The latch pin may fit closely within the latch pin aperture. The pre-tensioning forced may thereby be distributed over as large a surface area of the latch pin as possible. For example, the internal diameter of the aperture may similar to the external diameter of the latch pin, to provide a close, or interference fit therebetween.

[0031] Where the latching apparatus comprises a latch pin, the pre-tensioning arrangement may be configured to engage along all or substantially all of the length of the latch pin extending from the latch pin aperture, in use, so as to distribute the transmitted pre-tensioning forces.

[0032] The pre-tensioning arrangement may comprise first and second jacking plates, moveable in relation to the second connector assembly to engage with the respective ends of the latch pin extending from the latch pin aperture to the first and second sides of the coupling portion.

[0033] The jacking plates may, in use, be positioned adjacent to the coupling portion of the pull line. The skilled person will understand that a gap between the jacking plates and the coupling portion may be desirable to facilitate pulling of the pull line (e.g. via a temporarily attached pilot line), but are desirably as close as possible so as to minimise the unsupported length of latch pin.

[0034] The first and second jacking plates may form part of a jacking plate collar, sized to extend around and to at least the first and second sides of the coupling portion. The jacking plate collar may include a port sized to extend entirely around the coupling portion, or may be open-sided (e.g. defining a U-shaped portion for receiving the coupling portion).

[0035] The first and second jacking plates may be provided with receiving formations, such as recesses, to engage with the ends of the latch pin.

[0036] The pre-tensionable connector apparatus may comprise first and second support plates, in fixed relation to the second connector assembly, the first and second support plates corresponding to the first and second jacking plates, wherein the pre-tensioning arrangement is configured to apply a the pre-tensioning force between the support plates and the jacking plates.

[0037] The first and second support plates may form part of a support plate collar, sized to extend around and to at least the first and second sides of the coupling portion. The support plate collar may include a port sized to extend entirely around the pull line or coupling portion thereof, or may be open-sided (e.g. defining a U-shaped portion for receiving the pull line or coupling portion).

[0038] The pre-tensioning force may be applied by any suitable means, including by hydraulic actuator(s), mechanically or electromechanically. For example, the pre-tensioning arrangement may include one or more hydraulic rams disposed between the support and jacking plates, operable to extend and move the jacking plates into engagement with the latch pin in use. Torqueing nuts and / or tensioning bolts may be used to reconfigure (either by pushing or pulling) the pre-tensioning arrangement. The pre-tensioning arrangement may be reconfigured by levering, for example by rotating a cam.

[0039] When connecting the first and second connector assemblies, a tensioning force may be applied by a winch, such that the pre-tensioning arrangement may be coupled to the pull line terminator, the winch released and the pre-tensioning force thereafter applied by the pre-tensioning arrangement.

[0040] The pre-tensioning arrangement is configured to be locked in place in the second configuration, to maintain the pre-tensioning force. Stated differently, the pre-tensioning arrangement is passively retained in the second configuration.

[0041] The term "passively retained" herein refers to the pre-tensioning arrangement being retained or locked in the second configuration without a hydraulic, electrical or any other type of mechanism requiring to be energised in order to maintain the pre-tensioning force. A passively retained pre-tensioning arrangement, may more reliably maintain the pre-tensioning force over a prolonged period (months or years), as might be required for example for semi-permanently moored vessels such as tidal generators, oil rigs and the like.

[0042] Passively maintaining, or locking, the pre-tensioning arrangement in the second configuration may also provide safety benefits, by avoiding risks otherwise associated with mechanical failure of energised apparatus for applying the pre-tensioning force.

[0043] A pre-tensioning arrangement may be passively retained for example by way or torqueing or tensioning nuts. Star washers or other retainers (e.g. a retainer applied to the head of the a retaining bolt) may be used to retain the tensioning nuts in the position, when the second configuration has been reached. A rotating cam may also be maintained or locked in position in an analogous manner.

[0044] A pre-tensioning arrangement may be passively retained by latching or introducing wedges, spacers, plates other members between components of the pre-tensioning arrangement, to block movement from the second to the first configuration. For example, the jacking plates as disclosed below may be lifted by means of a hydraulic or electromechanical actuator or the like, and one or more spacers introduced between the jacking plates and the support plates to passively retain the pre-tensioning arrangement in the second configuration, such that the actuator(s) need not remain energised.

[0045] The connector apparatus may comprise a spacer structure extending between the second connector assembly and the pre-tensioning arrangement. The spacer structure may extend for example between the second connector assembly and the support plates, and at least in part maintain the second connector assembly and support places in their fixed relation to one another.

[0046] The pre-tensioning arrangement and second connector assembly may be retained in fixed relation to the spacer structure. The pre-tensioning arrangement may be attached to, or fixed proximal to, one end of the spacer structure, and the second connector assembly may be attached to, or fixed proximal to, the other end of the spacer structure.

[0047] The spacer structure may further provide a pathway for pulling the pull line, in order to bring the first and second connector assemblies into engagement with one another.

[0048] The spacer structure may be a generally tubular structure, such as a moon pool through the hull of a floating vessel, as disclosed herein.

[0049] The support plate(s) may be attached to, or proximal to, an end of the tubular structure.

[0050] The pre-tensioning arrangement (e.g. support plate(s) thereof) may be attached to, or fixed proximal to, an upper end of the tubular structure or moon pool.

[0051] The pre-tensionable connection apparatus may be for use in securing a mooring line to a floating vessel.

[0052] The pull line may be flexible. For example, the pull line may comprise a length of cable, chain or the like. A flexible pull line assists in puling the first and second connector assemblies together from a range of respective alignments: For example, where one or both of the first and second connector assemblies may be prone to move during connection, such as when connecting a mooring line to a floating vessel.

[0053] The first connector assembly may be a male connector assembly. The second connector assembly may be a female connector assembly.

[0054] The first and second connector assemblies may be adapted to be brought together from a range or respective alignments. For example, one or both may be tapered, as disclosed herein.

[0055] The first and second connector assemblies may be male and female connector assemblies as disclosed herein.

[0056] The connector apparatus may further comprise a shield or cover, for enclosing the pre-tensioning arrangement and coupling portion of the pull line. The shield or cover may be removable or retractable, so that the upper end of the coupling apparatus can be covered once the coupling apparatus has been pre-tensioned.

[0057] The connector apparatus may be configured for one or more further lines, such as hydraulic lines, electrical distribution lines or the like, to be connected, and to pass the male and / or female connector assemblies. For example, the male connector assembly may comprise one or more further connectors, or channels.

[0058] The invention extends in a second aspect to a moon pool for a floating vessel according to claim 10.

[0059] The moon pool may comprise a female connector assembly at or proximal to the lower end of the tubular structure.

[0060] The female connector assembly may define a female longitudinal axis and having a connector collar configured to cooperatively engage around an intermediate portion of a male connector assembly; the female connector assembly comprising a first pin receptor on a first side of the female connector assembly and a second pin receptor on an opposite second side of the female connector assembly; wherein the pin receptors are configured to engage with outwardly extending pins of a said male connector assembly.

[0061] The female longitudinal axis may be coaxial with the longitudinal axis of the tubular structure. The moon pool may comprise a pre-tensioning arrangement positioned in fixed relation to the female connector arrangement, at or proximal to the upper end of the tubular structure; the pre-tensioning arrangement being reconfigurable between a first configuration and a second configuration, 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, as disclosed herein in relation to the first aspect.

[0062] In use, the moon pool may further comprise a male connector assembly.

[0063] The male connector assembly may be connected, typically via an upper end portion, to a pull line, by which the male and female connector assemblies may in use be pulled into engagement with one another. In use the pull line may extend through the tubular structure.

[0064] The pull line may comprise a coupling portion being adapted to be coupled to the pre-tensioning arrangement by coupling apparatus.

[0065] The male connector assembly may have an upper end portion for attachment to a pull line; and a lower end portion for attachment to a mooring line; a first pin portion extending from the connector body normal to a male longitudinal axis extending between the upper and lower ends of the connector body; and a second pin portion extending from an opposite side of the connector body normal to the male longitudinal axis; the male assembly being couplable to the female connector assembly; wherein, when the male connector assembly is connected to the female assembly, the collar cooperatively engages around the intermediate portion of the male connector assembly, the first and second pin portion engage with the respective first and second pin receptors.

[0066] A mooring line may be attached to the male connector assembly. The mooring line may be attached to the male connector assembly via the pivotable coupling, optionally via two or more pivotable couplings in series.

[0067] The mooring line may be retained at the sea bed by an anchor.

[0068] Two or more mooring lines may be attached to the male connector assembly.

[0069] Also disclosed is a floating vessel comprising the moon pool of the second aspect.

[0070] The moon pool may extend through the hull of the vessel, such that the lower end of the moon pool is submerged. Accordingly, the female connector assembly and male connector assembly may in use be submerged.

[0071] The upper end of the moon pool may be on a deck of the vessel, or within the vessel.

[0072] The moon pool may be of wider diameter than the tubular structure, for example to facilitate connection of other services, such as power distribution cables.

[0073] The vessel may be a floating water current power generator, such as a tidal turbine. The vessel may include downwardly depending support structures to which are mounted nacelles and rotatable turbines. The turbines may be configured to have adjustable or reversible pitch. The floating water current power generator may for example be generally as disclosed in WO2009 / 141617 (Scotrenewables (Marine Power) Limited), or as disclosed in WO 2018 / 115806 (Orbital Marine Power Limited).

[0074] Floating vessels of this type are subject to large forces applied by water currents, which may act to move the male and female coupling assemblies in relation to one another, by causing pitch or roll and consequent tension via the mooring lines. Pre-tensioning forces reduce or eliminate any such movement between the male and female connection assemblies.

[0075] The invention is not restricted to any particular type of vessel, however, any may be used for example in connection with a floating wind turbine, a wave generator, a floating offshore production platform or service vessel or the like.

[0076] The vessel may include more than one moon pool. For example, the vessel may include a moon pool at or near the bow of the vessel and / or at or near the stern of the vessel.

[0077] A third aspect of the invention relates to a method of connecting the pre-tensionable connection apparatus according to claim 11.

[0078] The method may comprise coupling the pull line to the pre-tensioning arrangement 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.

[0079] The method may comprise reconfiguring the pre-tensioning arrangement to both bring the first and second connector assemblies into full engagement (by which we mean their final positions in relation to one another) and apply the pre-tensioning force.

[0080] The method may comprise applying a first force to the pull line between the first and second connector assemblies, wherein the first force is equal to or greater than the pre-tensioning force, coupling the pre-tensioning arrangement 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.

[0081] In some embodiments, the pre-tensioning arrangement is coupled to the pull line when the pre-tensioning arrangement is in the first configuration. In some embodiments, the pre-tensioning arrangement is coupled to the pull line when the pre-tensioning arrangement is in the second configuration.

[0082] The method may comprise tensioning the pull line, for example using a winch secured to the pull line (e.g. to the coupling portion), then coupling the pull line to the pre-tensioning arrangement. Where the pull line is tensioned by applying the first tensioning force before coupling to the pre-tensioning arrangement, the tensioning is then released such that the pre-tensioning force remains and is applied or maintained by (i.e. in such embodiments taken up by) the pre-tensioning arrangement.

[0083] The pull line may be tensioned prior to coupling to a smaller amount than the pre-tensioning force ultimately applied by the pre-tensioning arrangement. For example, the pull line may be tensioned, the pre-tensioning arrangement coupled thereto; the pre-tensioning arrangement optionally at least partially reconfigured, the tensioning released, and the pre-tensioning arrangement further reconfigured to increase the applied tension to the pre-tensioning force.

[0084] As disclosed herein. the method may comprise temporarily over tensioning the pull line (i.e. by a first tensioning force greater than the pre-tensioning force), then coupling the pre-tensioning arrangement and the pull line, reconfiguring the pre-tensioning arrangement and then releasing the over tensioning applied to the pull line.

[0085] The method may comprise placing a latch pin through a latch pin aperture in the coupling portion. The method may comprise engaging the pre-tensioning arrangement with the latch pin to the first and the second sides of the coupling portion.

[0086] The latch pin may be inserted through the latch pin aperture before, or after, the coupling portion has been moved adjacent to the pre-tensioning arrangement.

[0087] The method may comprise pulling the pull line to bring the first and second coupling assemblies into engagement with or into proximity to one another. In some embodiments, a pilot line may be attached to the pull line and the pilot line used to pull the pull line and bring the first and second connector assemblies into engagement with or proximity to one another. The method may comprise pulling the pull line via a moon pool on a floating vessel. Thus, the pull line may be pulled from above the water line of the floating vessel, to bring a subsurface first connector assembly into engagement with or proximity to the second connector assembly.

[0088] When connected together, the first and second connector assemblies may share a common axis. The method may comprise bringing them into engagement from non-axially aligned positions (non-aligned in terms of their orientation and / or lateral positions). A flexible pull line facilitates the alignment of the first and second connector assemblies.

[0089] As disclosed herein, the connector assemblies may be provided with tapered surfaces to facilitate alignment, and provide some degree of tolerance to being urged together from non-aligned positions.Description of the Drawings

[0090] Example embodiments will now be described with reference to the following figures in which: Figure 1 shows a floating water current power generator; Figure 2 shows a floating vessel (a further water current power generator) comprising connection apparatus in bow and stern moon pools; Figure 3 shows a cross sectional perspective view of a moon pool, comprising connection apparatus; Figures 4(a) and 4(b) show perspective "X-ray" and partial cross sectional views of a connector assembly; Figure 5 shows a perspective view of a body of a male connector assembly; Figure 6 shows a perspective view of a female connector assembly; Figure 7 shows the connector apparatus while the male connector assembly is being pulled towards the female connector assembly; Figure 8 shows a perspective cross sectional view of the connector apparatus, viewed from below the vessel of Figure 2; Figure 9 shows a perspective cross sectional view of a pre-tensioning arrangement for applying a pre-tensioning force between connector assemblies; Figure 10 shows a coupling portion at the end of a pull line; and Figure 11 shows a perspective view of a pre-tensioning arrangement, from above. Detailed Description

[0091] Figure 1 shows a side view of a floating vessel 1, in this instance a water current power generator 1, extracting energy from flowing water. In normal use, the apparatus floats on a body of water 2 and is moored to the bed (not shown) of the body of water via mooring line, in this instance cables 4, attached to eyelets 6, in a conventional manner.

[0092] The vessel 1 is a marine tidal turbine, adapted to extract energy from a tidal flow. The vessel has a buoyancy vessel 3, and a turbine assembly 5 coupled to each side of the buoyancy vessel. Each turbine assembly 5 has a nacelle 7, to which a turbine rotor 9 is rotatably mounted. The rotors 9 comprise rotor blades 17 attached to a hub 19. The nacelle 7 is coupled to the outboard end 10 of a support structure 11. At its inboard end 12, the support structure is coupled to the buoyancy vessel 3. The forces applied to the buoyancy vessel 3 by water flowing past the rotors 9 can be considerable.

[0093] Figure 2 shows a side view of a floating vessel 1', having a moon pool 10 towards the bow and stern sections thereof (shown in outline), which incorporates an embodiment of connection apparatus 50, which provides for improved engagement with a mooring line and facilitates connection of the mooring line when the vessel is moving for example due to waves.

[0094] In this embodiment, the cables 4 are attached to the lower portion of a male connector assembly 100, which is coupled to a female connector assembly 200 at the base of the moon pool. The male and female connector assemblies 100, 200 are pre-tensioned against one another, by a pre-tensioning arrangement indicated generally as 300.

[0095] The features of the male and female connector assemblies 100, 200 and the pre-tensioning arrangement 300 will be described in further detail below, with reference to Figures 3-10.

[0096] Figure 3 shows a perspective cross sectional view of a moon pool 10. The moon pool has a tubular structure 12, which extends through the hull of the buoyancy vessel 3, in this embodiment through to the upper deck 8.

[0097] The connection apparatus 50 includes, attached to the lower end 14 of the tubular structure, male and female connector assemblies 100, 200. A pull line 150 (in this instance, a chain) extends from an attachment (eyelet 102) at the upper end portion 104 of the male connector assembly, along a longitudinal axis L to a pre-tensioning arrangement 302, at the upper end 16 of the tubular structure 12. In the embodiment shown the pre-tensioning arrangement is secured directly to the tubular structure, which serves in part to act as a spacer to maintain the pre-tensioning arrangement 302 in fixed relation to the female connector assembly 200. In alternative embodiments, the pre-tensioning arrangement may be attached to another part of the vessel 1.

[0098] In the configuration shown, the connector assemblies 100, 200 are cooperatively engaged and a pre-tensioning force to hold them together is applied by the pre-tensioning arrangement 302, via the pull line 150.

[0099] Figures 4(a) and 4(b) show a perspective view of the connector apparatus 50 at the lower end 14 of the tubular structure, with Figure 4(b) shown in partial cross section. The male connector assembly 100 includes a connector body 101. An intermediate portion 106 of the body 101 is cooperatively engaged with a collar 202 of the female connector assembly 200.

[0100] A first pin portion 108 of a pin 110 extends laterally from the male connector assembly 100, normal to a male longitudinal axis M extending through the assembly 100. A second pin portion of the pin 110 extends laterally from the opposite side of the assembly 100 and is not visible in the figure.

[0101] The collar 202 of the female connector assembly 200 is attached by a flange portion 204, to a corresponding flange 18, at the bottom of the tubular structure, by bolts 20. The collar 202 defines a female longitudinal axis F, and is profiled so as to cooperatively engage with the intermediate portion 106 of the body 101.

[0102] The female connector assembly 200 also includes a first pin receptor 208, which is connected to and extends below the flange portion 204. A second pin receptor is positioned on the diametrically opposite side of the female connector assembly 200.

[0103] When the male and female connector assemblies 100, 200 are coupled so that the collar 202 cooperatively engages the intermediate portion 106, as in Figure 4(a) and (b), the first pin portion 108 is engaged with the first pin receptor 208, and the second pin portion engages with the second pin receptor on the opposite side of the apparatus 50. The interaction between the pin portions and pin receptors restricts rotational motion between the male and female connector assemblies.

[0104] Figure 5 shows a perspective view of the body 101 of the male connector assembly. The body has an upper end portion 104, which includes an eyelet 102 for attachment to the pull line 150. The intermediate portion 106, includes a tapered, frustoconical surface 106', angled towards the collar 202 in use.

[0105] The lower end portion 108 of the body 101 is provided with a series of co-axial eyelets 112a-c, sized to receive the pin 110. The eyelets extend through corresponding outer coupling formations 114a, 114c and an intermediate coupling formation 114b. The coupling formations form the female components of pivotable couplings, which are able to rotate around the pin 110.

[0106] Figure 6 shows a perspective view from below the female connector assembly 200, showing more clearly an inwardly facing, frustoconical surface 206 configured to cooperatively engage with the corresponding surface 106' of the body 101.

[0107] The first 208 and second 212 pin receptors can also be seen in Figure 6(b). The pin receptors are formed as a U-shaped member, which defines pairs of abutting members 214 extending below the collar. A bolt hole 220 is located at the "base" of the U-shaped portion of each of the receptors 208, 212, by which they are bolted to the flange portion 204 and the flange 18.

[0108] Each of the members 214 include a ramped guide surface 216, which serve in use to guide the pin portions towards their final positions in the rounded recess 218 at the base of each pair of abutting members 214. In the embodiment shown, the opposed ramped guide surfaces 216 define a tapered entrance to the pin receptors 208, 212, which narrows towards the recesses 218.

[0109] The abutting members 214 are thus able to "capture" an approaching pin portion from within a range of rotational angles (i.e. between an axis defined along the pin portions, or pin, and extending between the recesses 218), as the male and female connector assemblies are moved together. In addition to this rotational tolerance, a degree of lateral tolerance is also provided by the ramped surfaces (i.e. distance between the axis along the pin portions and the female longitudinal axis, as the male connector assembly approaches.

[0110] The length of the connector body along the axis M is also relatively small, in comparison to its with. In particular, the longitudinal distance along the male longitudinal axis M between the intermediate portion 106 and the upper end 105 of the male connector assembly 100 is relatively small compared to the diameter (at its narrowest point) of the collar 202. In the embodiment shown, the ratio of this length to diameter is around 3:1.

[0111] Figure 7 shows the connector apparatus while the male connector assembly is being pulled towards the female connector assembly. The pull line 150 is omitted for clarity. Figure 7 illustrates the lateral (T L ), rotational (T R ) and angular (T A ) tolerance provided by the above described dimensions of the male connector assembly in relation to the female connector assembly; and the guide arrangements associated with the pin receptors.

[0112] Figure 8 shows a further perspective cross sectional view of the apparatus 50, viewed from below the vessel 1', with the male and female connector assemblies 100, 200 cooperatively engaged.

[0113] The male connector assembly 100 includes a pivotable coupling at its lower end portion, which includes a medial member 120, having an eyelet 122 through which the portion 112 of the pin 110 extends. The medial member 120 is pivotable around the pin 110.

[0114] At the opposite end of the member 120, is another eyelet 124, perpendicular to the eyelet 122.

[0115] The assembly 100 further incudes a connecting arm 126, having plates 126a and 126b, with eyelets 128a-d at the ends thereof. A connector pin 130 extends through the eyelets 128c, 124 and 128d, to pivotably couple the connecting arm 126 to the medial member 120, and thereby provide a further pivotable coupling is provided in series with the coupling around the pin 110. The medial member 120 in effect provides the inner part of a clevis joint at each of its ends, with the outer parts being provided at one end by the formations 114a and 114b, and at the other end by the ends of the connecting plates 126a and 126b.

[0116] At the distal ends of the plates 126a,b, a mooring line 4 can be connected (not shown), via a pin, in a conventional manner.

[0117] As can be seen in most clearly in Figures 4(a)-(b) and 7, the male connector assembly also includes two pairs of pivotable couplings in parallel, including a medial member 120' and connecting arm 126' similarly coupled to the pin portion 108, between the formations 114b and 114c of the body 10. Accordingly, in the embodiment shown, two mooring lines may be connected to the male connector assembly 100.

[0118] Figure 9 shows a perspective cross sectional view of the pre-tensioning arrangement 302. Figure 10 shows a coupling portion 160 at the end of the pull line.

[0119] The pre-tensioning arrangement 302 includes a support plate collar 304, having an outer flange 306 by which the support plate collar 304 is fixed to the top of the tubular structure 112, to maintain the pre-tensioning arrangement in fixed relation to the female connector assembly.

[0120] The support plate collar 304 includes a lower liner section 308 which extends into the top part 116 of the tubular structure, and an upper section 310, which defines a port 312 to the moon pool. Triangular bracings extend between the upper section 310 and the liner section 308, around the port 312, to distribute pre-tensioning forces and other loadings applied via the pull line, in use. The uppers surface of the upper section 310 defines a support plate 316, having first and second support plate regions 316a and 316b, on opposite sides of the port 312. In alternative embodiments, separate first and second support plates may be provided.

[0121] A jacking plate collar 320 is slideably mounted above the support plate 316, on bolts 322. The jacking plate collar 320 defines first and second jacking plate regions 320a and 320b, above the first and second support plate regions 316a and 316b.

[0122] The coupling portion 160 is attached at its lower end to the pull line. In the embodiment shown, the pull line is a length of chain 150 secured within a clevis in the lower end of the coupling portion 160 by a pin 162.

[0123] The coupling portion further includes a latch pin aperture 164, extending therethrough. When the coupling portion 160 is aligned with the pull line, the latch pin aperture is perpendicular to the pull line. A latch pin 166 extends through the latch pin aperture, and the lengths of the pin 166a and 166b extending to either side of the coupling portion 160, rest upon the first and second jacking plate portions 320a and 320b. A recess 324a, 324b is provided on each jacking plate portion, to assist in seating the latch pin.

[0124] Hydraulic jacks 330 are disposed between the support plate 316 and the jacking plate 320, (see Figure 11) and may be extended to reconfigure the pre-tensioning apparatus form the first configuration shown in the figure to the second configuration in which the jacking plates abut the ends of the bolts 332. Other means of reconfiguring the pre-tensioning arrangements disclosed herein may also be used, such as screw actuators, levers or the like, which may be electromechanically or hydraulically, or mechanically actuated.

[0125] In use, to couple the male and female connector assemblies together, the pull line is pulled up through the tubular member 112, by a pilot line (not shown) which drops through the moon pool 110. As shown by way of example in Figure 7, when the male and female connector assemblies are close to one another and within the axial, radial and lateral tolerance, they are guided into alignment by the guide arrangements associated with the pin receptors, by further pulling upon the pull line.

[0126] When the male and female assemblies 100, 200 are close to being engaged, or loosely engaged, and before the pre-tensioning arrangement 302 has been extended (i.e. when in the first configuration), the coupling portion 160 is pulled sufficiently for the latch pin aperture 164 to be above the jacking plate 316. The latch pin 166 is then inserted through the latch pin aperture 164 and either the jacking plate raised, or more typically the coupling portion slightly lowered, such that the latch pin ends 160a 160b rest in the recesses 324a and 324b.

[0127] At this stage the male and female connector assemblies 100, 200, may be loosely engaged. For example, the portions 108, 112 of the pin 110 may be within the pin receptors, but not fully engaged in the recesses 218. Similarly, the collar 206 and intermediate potion 106 may be slightly disengaged, and / or the axes M, F and / or L slightly misaligned. In addition, the pull line 150 may have some slack.

[0128] The pre-tensioning arrangement may then be extended to the second configuration, by actuating the hydraulic jacks 330. This at least applies a pre-tensioning force, and in the embodiment shown, pulls the male and female connector assemblies into full cooperative engagement.

[0129] As can be seen from Figure 9, the interior of the latch pin aperture is generally tubular, such that the coupling portion 160 engages with the latch pin over a portion of the length of the latch pin extending therethrough (rather, for example, at a single point, as between links formed between two members of round cross section). In addition, a substantial portion of the exposed ends 166a and 166b of the latch pin 166 are supported by the jacking plate.

[0130] The pre-tensioning force (and any additional force applied via the mooring lines in use) is therefore effectively transmitted via these contacting lengths, to the jacking plate and outwardly to the support plate collar 304 from the upper part 310 to the lower part 308, via the plates 314. Similarly, the counter forces are distributed via the comparatively wide diameter coupling portion 160 to the pull line, chain 150, rather than directly and in a more focussed manner, to a chain link.

[0131] Spacers 332 can be inserted between the jacking plate 320 and support plate 316, to passively retain the pre-tensioning arrangement in the second configuration, to obviate the need to maintain hydraulic pressure, or to safeguard against a loss of hydraulic pressure. Whilst the invention has been described in connection with the foregoing illustrative embodiments, various modifications, additions and alterations may be made to the invention by one skilled in the art without departing from the scope of the claimed invention as defined by the following claims.

Claims

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.