Gateway node

Abstract

A connection node for a subsea cable, the connection node comprising: a housing arranged between first and second connection ends; a connection socket arranged to be stored within the housing; at least one aperture located within the housing configured to allow the connection socket to be accessed via the aperture; wherein the connection node is configured to be connected in-line with a subsea cable via the first and second connection ends.

Description

[0001] GATEWAY NODE

[0002] Field of Invention

[0003] The present invention relates to wet-mate connectors for subsea telecommunication cables.

[0004] Background

[0005] The ocean is a generally hostile environment for electrical assemblies. Saltwater in particular is very damaging due to its corrosive properties. If electrical components, such as connector contacts or parts of the metal connector body, are exposed to saltwater they will eventually corrode, causing electrical failure. Subsea connections between subsea cables therefore need to be able to be mated and de-mated within this hostile environment and a full ocean pressure.

[0006] A wet-mate connector is a specially designed connector which can be mated or unmated in wet environments. Generally, wet-mate connectors rely on a watertight seal at the junction where the subsea cable is most vulnerable to water ingress. Preventing the ingress of water prevents the electrical components from coming into contact with the sea water which helps reduce corrosion.

[0007] Wet-mate connectors greatly reduce the need to bring cables to the ocean surface by enabling safe subsea connection and disconnection of subsea cables. Wetmate connectors can reduce installation time and reduce the size of vessels required for cable management.

[0008] Wet-mate connectors have a wide variety of applications such as subsea control modules, umbilical terminations, and junction boxes.

[0009] Generally, if additional cables are to be connected to a main subsea cable system, branching unit assemblies can be combined with the wet-mate connectors. However, interfacing with the main backbone subsea cable generally requires a bespoke solution that requires non-standard telecoms deployment and installation.

[0010] It would be advantageous to provide a simpler mechanism for connecting further cables to a subsea cable system.

[0011] Summary of Invention

[0012] According to an aspect of the invention there is provided a connection node for a subsea cable. The connection node comprises a housing arranged between first and second connection ends, a connection socket arranged to be stored within the housing, and at least one aperture located within the housing configured to allow the connection socket to be accessed via the aperture. The connection node is configured to be connected in-line with a subsea cable via the first and second connection ends.

[0013] The connection node comprising a connection socket enables safe subsea connection and disconnection of subsea cables. The connection node acts to form a passive branching unit so that a branched or spur connection to a main subsea cable system can be made. The connection node can be used with both repeated and unrepeated backbone subsea cable systems. The connection node may be configured to connect with a subsea cable using standard telecommunication technology.

[0014] The connection socket of the connection node provides a pre-deployed connection point on the seabed, allowing for connection of spur cables, or commercial, scientific, or military equipment subsequent to the main cable being laid.

[0015] The connection node avoids the need to bring the subsea cable to the surface to make subsequent connections to the backbone cable. This significantly reduces device and array deployment and retrieval times leading to substantial cost savings. Having a pre-deployed connection point ready for use also means that connections can be made in a much shorter timeframe. This can allow connections to be made in waters with limited time windows e.g. due to tides. This may be particularly relevant for applications where changing tides or wave actions can limit access times.

[0016] Preferably the connection socket is a wet-mate connector. This allows a connection to be made between the connection node and an external connection point in wet environment, in particular in subsea environments. By external, we mean that the connection point is a connection point that is not part of the connection node for example, but not limited to, an additional subsea cable or a piece of scientific or monitoring equipment.

[0017] In some example, the connection socket may comprise a female connecting portion. In other examples, the connection socket may comprise a male connecting portion. This allows the connection node to be connected to a variety of external connection points. The connection node is not limited to being connected with a specific form of connector.

[0018] Preferably, the connection node may further comprise an optical fibre pair and a power conductor. The connection socket may be configured to communicate with a subsea cable via the optical fibre pair and power conductor. In this way, the optical fibre pair and power conductor may provide an opto-electrical connection between the subsea cable and the connection socket.

[0019] In some developments the optical fibre pair and power conductor may be located within a hose. The hose may be a flexible hose. The hose may be an oil-filled hose. The hose may provide flexibility to allow the connection socket to be removed from the housing. The hose may additionally provide a pressure- balanced environment for the optical fibre pair to help with optical fibre pair withstand the conditions of the subsea environment. The connection node may further comprise a breakout housing. The breakout housing may be configured to allow the optical fibre pair and power conductor to be broken out from a subsea cable and form a connection with the connection socket. The breakout housing may provide a hermetically sealed environment in which the breakout of the optical fibre pair and power conductor can be carried out safely.

[0020] The optical fibre pair and power conductor may be routed through the breakout housing via a flexible link. The flexible link may be located between a first bulkhead and a second bulkhead within the breakout housing.

[0021] The breakout housing may be arranged between the housing and a connection end of the connection node. Preferably, the breakout housing may be arranged between the housing and the first connection end of the connection node. This may allow the breakout to help transfer axial cable load from the subsea cable to the connection node.

[0022] The first and second connection ends of the connection node may be configured for connection with first and second universal joints of a subsea cable. This may allow standard cable termination technology to be utilised to provide termination of the cable strength members.

[0023] In some developments, the housing may comprise a plurality of apertures. Each aperture of the plurality of apertures may be configured to allow the connection socket to be accessed via the aperture. This means that access to the connection socket via an aperture is not dependent on the orientation of the connection node.

[0024] The at least one aperture comprises a cover. If the housing comprises a plurality of apertures, one, some or all of the plurality of apertures may comprise a cover. The cover may reduce silting and help prevent foreign bodies from entering the housing. Preferably, the one or more covers are releasably attached to the housing. This allows the cover to be removed when access to the connection socket is required and replaced when access to the connection socket is not needed. In some cases, the one or more covers may be movable between an open position and a closed position. In this case, the one or more covers may be attached to the housing. This may prevents the cover from being lost or misplaced, in particular during times when the connection socket is being accessed.

[0025] The housing may comprise a dummy connection point configured to receive the connection socket. This may allow the connection socket to be securely and safely stored within the housing when the connection socket is not being used.

[0026] In some examples the connection node may further comprise a frame. The frame may be configured to support at least a portion of the connection socket within the housing. The frame me support the connection socket within the connection node to hold the connection socket stable relative to the connection node.

[0027] Preferably, the frame comprises at least one arm having a slot and a socket support. The socket support may be configured to receive the connection socket and may be further configured to move along the slot. The socket support may facilitate movement of the connection socket. The socket support may allows the connection socket to be moved between and stowed position in which the connection socket is located within the housing and a deployed position in which the connection socket at least partly extends through the aperture in the housing.

[0028] Throughout the disclosure, a connection node may also be referred to as a gateway node.

[0029] The connection node further comprises a multi-axis joint configured to allow multidirectional movement of the connection socket. Preferably, the multi-axis joint is a ball and socket style joint. The multi-axis joint may be configured to allow movement in three distinct directions. The multi-axis joint may comprise a frame having at least one slot arranged to allow movement of the connection socket along the slot. The frame may be referred to as a mounting ball. The frame may have a curved outer surface. The frame may have a round outer surface. The outer surface of the frame may facilitate smooth movement of the connection socket.

[0030] The connection node may comprise a socket support configured to support the connection socket. The connection node may be connected to an end of the socket support. The socket support may be configured to move along the slot to cause movement of the connection socket.

[0031] The multi-axis joint may comprise a disc portion having a curved surfaced complementary to a curved outer surface of the frame. The disc portion may be sized and shaped to slide smoothly over the outer surface of the frame to facilitate smooth movement of the connection socket.

[0032] Preferably, the socket support may be configured to pass through a hole in the disc portion. The hole may be a central hole. The socket support may be arranged to abut a portion of the disc portion. The socket support may be arranged to abut a circumference of the hole of the disc portion.

[0033] The frame may comprise a plurality of slots, preferably three slots. The plurality of slots are preferably equally spaced apart from each other around the frame.

[0034] The connection node may further comprise a second locking mechanism configured to prevent movement of the connection socket in a locked position and allow movement of the connection socket in an unlocked position.

[0035] The second locking mechanism may comprise a latch configured to engage with a portion of the multi-axis joint in the locked position. In the unlocked position, the latch may not be engaged with the multi-axis joint. The latch may comprise a ridge configured to engage with a lip on the disc portion when the second locking mechanism is in the locked position.

[0036] The latch may comprise a release configured to disengage the latch from the portion of the multi-axis joint. The latch may comprise a release configured to disengage the ridge from the lip on the disc portion. The release may also be referred to as a leaf. The release, or leaf, may comprise the ridge.

[0037] The release may be a leaf spring. Preferably, the leaf spring may comprise a bias, for example due to the material out of which the release is made, such that the second locking mechanism is biased in the locked position.

[0038] The cover may comprise a first locking mechanism configured to prevent the cover from being removed from the housing when the first locking mechanism is in a locked position and allow the cover to be removed from the housing when the first locking mechanism is in an unlocked position.

[0039] The first locking mechanism may comprise a rotatable locking element configured to adjust the first locking mechanism between the locked and unlocked positions. The rotatable locking element may be a form of actuator.

[0040] The rotatable locking element may comprise a receiving slot configured to receive a locking key.

[0041] The first locking mechanism may comprise at least one locking pin configured to engage with a portion of the housing when the first locking mechanism is in the locked position. When the first locking mechanism is in the locked position, the locking pin may be in a locked state. When the first locking mechanism is in the unlocked position, the locking pin may be in an unlocked state.

[0042] The rotatable locking element may comprise at least one cam profile comprising a steep side and a sloped side. The cam profile may also be referred to as a cam surface or simply a cam. The at least one locking pin is preferably configured to engage the at least one cam profile when the first locking mechanism is in the unlocked position.

[0043] The first locking mechanism may comprise a biasing element configured to bias the first locking mechanism in the unlocked position. The biasing element may be configured to bias the locking pin in its unlocked state. The biasing element may be configured to bias the locking pin towards an unlocked position of the locking pin.

[0044] Brief Description of Drawings

[0045] Embodiments of the invention will be described by way of example only with reference to the accompanying drawings in which:

[0046] Figure 1 shows an example connection node;

[0047] Figure 2 shows a cross-section of part of a connection node;

[0048] Figure 3 shows part of a connection node;

[0049] Figure 4 shows part of a connection node;

[0050] Figure 5 shows an example application for a connection node;

[0051] Figure 6 shows another example application for a connection node;

[0052] Figure 7 shows another example application for a connection node;

[0053] Figure 8 shows another example connection node;

[0054] Figure 9 shows the other example connection node;

[0055] Figures 10a and 10b show part of a connection node;

[0056] Figures 11a and 11 b show part of a connection node;

[0057] Figure 12 shows part of a joint of a connection node;

[0058] Figures 13a and 13b show part of a connection node;

[0059] Figures 14a and 14b show part of a connection node;

[0060] Figure 15 shows a cover of a connection node;

[0061] Figure 16 shows a connection node;

[0062] Figures 17a and 17b show a cover of a connection node;

[0063] Figures 18a and 18b show a cover of a connection node; Figure 19 shows a connection node and cover;

[0064] Figures 20a and 20b show part of a connection node;

[0065] Figure 21 shows part of a locking mechanism;

[0066] Figure 22 shows part of a locking mechanism;

[0067] Figures 23a and 23b show part of a connection node;

[0068] Figures 24a and 24b show part of a locking mechanism;

[0069] Figure 25 shows a connection node and connection socket;

[0070] Figure 26 shows part of a locking mechanism;

[0071] Figure 27 shows part of a locking mechanism;

[0072] Figure 28 shows a connection node and connection socket; and Figure 29 shows a connection node and connection socket.

[0073] Detailed Description

[0074] Figure 1 shows an example connection node 2 to be used with subsea cables. The connection node 2 comprises a housing 4 arranged between a first connection end 6 and a second connection end 8. The connection node 2 further comprises a connection socket 10 which is arranged to be stored within the housing 4. An aperture 12 is located within the housing 4 and is configured to allow the connection socket 10 to be accessed via the aperture 12. The connection node 2 is configured to be connected in-line with subsea cables via the first and second connection ends 6, 8.

[0075] The connection node 2 is a form of wet-mate connector in that it provides an environmentally isolated connection point via the connection socket 10. The connection socket 10 allows a connection to be made between the main subsea cable system and an additional cable or component which branches off from the main system.

[0076] The connection node 2 generally provides a wet-mate hybrid optical I power interface or optical only I power only interface within a standard subsea telecommunications cable, utilising unlit or dedicated fibres (e.g. up to four fibre pairs). The connection node 2 is capable of being deployed in-line, in a similar manner as a standard subsea telecommunication repeater, without the need for specialist equipment. Once on the seabed the, the connection node 2 may be accessed by a remote operated vehicle (ROV), which is able to make a connection to external equipment or other telecommunications cable on demand via the connection socket 10.

[0077] Further details of the connection node 2 will now be described.

[0078] The first and second connection ends 6, 8 each connect with a main subsea cable via a universal joint style termination point 14. The connection node 2 therefore utilises a standard cable termination based on universal joint technology in order to provide termination of the cable strength members.

[0079] Bend limiters 16 are located at either end of the connection node 2, between the connection node 2 and the subsea cables, in order to limit the bending radius of the cable. This helps prevent excessive bending movements and stress in the subsea cable, as well as help transfer load through the structure of the connection node 2.

[0080] Generally, electrical power and optical connections between the subsea cable and the connection socket 10 are provided by a breakout of suitable cables from the main cable structure within the subsea cable, the breakout being provided by a breakout housing 18 located next to the housing 4 of the connection node 2. Typically, the breaking out involves breaking out an optical fibre pair and power conductor from the subsea cable which are used to form the connection socket 10. Axial cable load is transferred from the subsea cable via a bend limiter 16 to the breakout housing 18.

[0081] Optical and electrical connection between the universal joint termination 14 and the breakout housing 18 are achieved using a carrier tube 20, as shown in Figure 2. The carrier tube 20 may be referred to as a pigtail. The carrier tube 20 is a metal carrier tube. This allows the carrier tube 20 to have a dual functionality by providing both electrical continuity of the cable power conductor and hydrostatic pressure protection for the interconnecting optical fibres. Electrical insulation of the carrier tube 20 is achieved by an external polyethylene (PE) sheath which surrounds the carrier tube 20. The sheath is amalgamated to the universal joint termination insulation through PE overmoulding using standard jointing techniques.

[0082] The carrier tube 20 is routed from the subsea cable to the bend limiter 16 where it is free of the axial cable load and protected from external aggression. The carrier tube 20 is then hermetically terminated to a hermetic bulkhead at one end of the breakout housing 18 using a bespoke hybrid optical / high voltage penetrator.

[0083] The breakout housing 18 provides an environment in which to safely extract the dedicated optical fibre pair(s) and power conductor for power supply which are intended for connection to the connection socket 10. The breakout housing 18 also routes the remaining optical fibres and power wires for onward uninterrupted transmission.

[0084] All the optical fibre and power connections are routed through the breakout housing 18 via a flexible link 22 between two bulkheads 24a, 24b within the breakout housing 18, from one bulkhead 24a to the other bulkhead 24b. Thus, at this stage, the dedicated optical fibre pair(s) and power conductor for the connection socket 10 have not yet been extracted. Each bulkhead 24a, 24b provides suitable storage for spare optical fibre, splices, and insulated power connection. A first bulkhead 24a at one end of the breakout housing 18 is a standard single gland bulkhead and feedthrough using a composite optical I power penetrator 28a. A second, opposing bulkhead 24b of the breakout housing 18, at the other end of the breakout housing 18, is a double feedthrough bulkhead to be used with both a hermetic penetrator 26 and hybrid optical I high voltage penetrator 28b. The hybrid optical I high voltage penetrator 28b is identical to the penetrator 28a used with the first bulkhead 24a. In some developments the flexible link may be replaced with an internal amplifier unit and suitable electronics. This may be required in examples where additional electronics or amplification is required for communication, such as for communication with sensors. As can be seen in Figures 2 and 3, at the second bulkhead 24b of the breakout housing 18, one or more selected optical fibre pairs are routed and connected to the connection socket 10, which forms the wet-mate connector, along with a power conductor to supply power to the connection socket 10 where required. The remaining transmission optical fibre pairs 32, along with power wires, are connected to the high voltage penetrator 28b for onward transmission via an extension of the carrier tube 20.

[0085] As already discussed, the connection node 2 comprises a housing 4. The housing 4 is located between the breakout housing 18 and a bend limiter 16, providing a connection between the breakout housing 18 and the bend limiter 16. This bend limiter 16 comprises a further cable termination, similar to that described previously in relation to the other bend limiter 16.

[0086] Generally, the housing 4 provides continuation of the axial load transfer between both ends of the subsea cable via the breakout housing 16, protecting both the optical and power routing through the structure of the connection node 2. The housing 4 provides additional crush protection to the internally mounted connection socket 10 during deployment and recovery.

[0087] As shown in Figure 3, internal to the housing 4, and external to the breakout housing 18, the wet-mate penetrator 26 is connected to the connection socket 10 via an oil filled, pressure balanced hose 34. The optical fibre pair and power conductor that have been broken out from the main subsea cable are located within the hose 34. The oil-filled hose 34 provides sufficient flexibility to allow the connection socket 10 to be extracted from the housing 4 so that the connection socket 10 can be mated with another, external connection point 36 as shown in Figure 4. The connection socket 10 can take the form of a plug (i.e. a male connection point) or a socket (i.e. a female connection point). Mating of the connection socket 10 with another cable is typically carried out by a ROV. The aperture 12 within the housing 4 allows the ROV to access the connection socket 10 from within the housing 4. In some cases, multiple apertures 12 can be provided around the external surface of the housing 4 so that the connection node 2 does not need to be orientated in a particular manner for the ROV to access the connection socket 10 within the housing 4. Each aperture may also comprise a cover, which may be removable by the ROV. The cover may reduce silting and foreign body ingress into the housing 4 until access is required.

[0088] A dummy connection point is provided within the housing 4, configured for connection with the connection socket 10, in order to allow the connection socket 10 to be securely stowed away during deployment and / or recovery of the connection node 2. The housing 4 has sufficient internal space to allow for storage of the oil-filled hose 34 when the connection socket 10 is not in use.

[0089] The connection socket 10 illustrated in at least Figures 1 to 4 is essentially freely floating, in that connection 10 can be moved around as a result of the flexibility provided by the oil-filled hose 34. The connection socket 10 is not held in place and so it is free to move around within the aperture 12 when the connection socket 10 has been extracted from the housing 4 and extends through the aperture 12, for example as showing in Figure 3.

[0090] In an alternative arrangement, as shown in Figures 8 and 9, the connection socket 10 can be held within a frame 38. The frame 38 comprises a plurality of support arms 40, each arm 40 having a slot 42 along which a socket support 44 can move. The connection socket 10 is held within the socket support 44 as shown in Figure 8. The frame 38 rests against an internal surface of the housing 4 using a plurality of frame feet 46. The socket support 44, which can move along the slots 42, allows the connection socket 10 to be moved between a deployed position illustrated in Figure 8 and a stowed position illustrated in Figure 9.

[0091] In the deployed position, the socket support 44 has moved along one of the slots 42 to allow the connection socket 10 to extend through the aperture 12. The socket support 44 helps retain the connection socket 10 in a substantially fixed position relative to the connection node 2 which can help facilitate connections between the connection socket 10 and an external connection point 36. The socket support 44 and the frame 38 may therefore help to stabilise the connection socket 10 when the connection socket is deployed.

[0092] In the stowed position, in Figure 9, the socket support 44 holds the connection socket substantially centrally with respect to the frame 38, such that the connection socket is substantially axially aligned within the connection node 2. The socket support 44 and the frame 38 may help to secure the connection socket 10 within the housing 4 when the connection socket 10 is not in use. This may help prevent the connection socket 10 from becoming damaged.

[0093] In summary, the connection node 2 provides a wet mate hybrid power and optical connection port (in the form of the connection socket 10) within a telecommunication cable, the connection port being deployed in-line with the donor system cable without the need for specialist equipment or operation. The proposed in line design would allow for sheave deployment and recovery of the port using both cable drum and linear cable engine (LCE) without impeding or delaying the lay speed of the vessel.

[0094] The connection node 2 can be thought of as a plug-and-play solution, providing a pre-installed connection point for use with a variety of different equipment and applications. The connection node 2 provides a pre-deployed connection point on the seabed which allows for post-lay connection of either a spur cable or commercial / military assets at a later time of convenience.

[0095] The connection node 2 is predominately designed for inclusion within new systems to provide a pre-planned connection point within the system. However, the connection node 2 may also be retrofitted to the cable if desired. Thus, advantageously, the connection node 2 is applicable to both unrepeated and repeated telecommunication cable systems.

[0096] The connection node 2 can be used for a number of different applications, some of which will be briefly described. In example telecommunication applications, as shown in Figure 5, an unrepeated spur cable 50 can be connected to the main backbone cable system at a later date, after the main cable system has been laid, via the connection socket 10 of the connection node 2. Thus, for telecommunication application, the connection node 2 removes the need to lay in a spur cable ahead of a branching unit deployment for later connection, and so spur cable can be deployed at a later date on demand.

[0097] In example science applications, as shown in Figure 6, a data sensor, observatory, or ocean monitoring equipment can be connected to the main cable system via the connection socket 10 in the connection node 2.

[0098] In example defense applications, as shown in Figure 7, the connection node 2 may provide a strategic connection point, via the connection socket 10, for coastal defense monitoring equipment or AUV charging and / or submersible communications without the need for resurfacing. For military applications, the inline deployment of the connection node 2 allows for covert installation of military equipment without the need for an installation vehicle, such as a ship, to loiter.

[0099] As mentioned in relation to Figures 8 and 9, the connection socket 10 can be held within a frame 38 comprising a plurality of slots 42 along which the socket support 44 can move in order to move the connection socket 10 along the slots 42. The frame 38, slots 42, and socket support 44 behave like a multi-axis joint, allowing multi-directional movement of the connection socket 10.

[0100] Another exemplary multi-axis joint 60 will now be described. Looking at Figure 10a the connection socket 10 is connected to a multi-axis joint 60, which is shown as a ball and socket style joint 60. As with previous arrangements, the connection socket 10 can be accessed via apertures 12 within the housing 4 as shown in Figures 11a and 11 b, and can be stowed in the housing 4 when not in use (as seen in Figures 10a and 10b). Figure 10b shows a front-on view of the multi-axis joint 60. Turning to Figure 12, the multi-axis joint 60 comprises a curved frame portion 62 having a hemispherical outer surface and a disc portion 64 which is also curved. The disc portion 64 has a curve complementary to the curved frame portion 62 such that the disc portion 64 can easily slide over the outer surface of the curved frame portion 62.

[0101] As with Figures 8 and 9, the connection socket 10 is attached to a socket support 44 which is sized to slide along a plurality of slots 66 within the curved frame portion 62. The socket support 44 passes through a central hole 68 in the disc portion 64, a lip 70 of the socket support 44 arranged to abut a part 72 of the surface of the disc portion 64. The abutment between the lip 70 and the part 72 of the disc portion helps prevent the connection socket 10 from retracting into the main body of the curved frame portion 62 or into any of the slots 66 in the curved frame portion 62, as well as helping ensure that the connection socket 10 does not get caught on any part of the curved frame portion 62. The disc portion 64 may also contribute towards smooth movement of the socket support 44 through the slots 66 by providing a smooth interface between the outer surface of the curved frame portion 62 and the inner surface of the disc portion 64.

[0102] As can be seen in partly in Figure 12, and in Figures 11 b, 13a-b, and 14a-b, the multi-axis joint 60 has three slots 66 equally spaced apart from each other around the curved frame portion 62 allowing the connection socket 10 to be moved in three different directions. The slots 66 in this arrangement are about 120 degrees apart from each other. Each slot 66 is associated with a corresponding aperture 12 (not shown in Figures 11 b, 13b, and 14b) allowing the connection socket 10 to be accessed by the respective aperture 12. This means that access to the connection socket 10 is not dependent on the orientation of the connection node 2 on the seabed. Instead, regardless of the orientation of the connection node 2, there will always be an aperture which is accessible such that the connection socket 10 is accessible.

[0103] It has been found that three slots 66, and three apertures 12, equally spaced around the curved frame portion 62 and housing 4 provides an optimized compromise between providing 360-degree accessibility to the connection socket 10 and maintaining the strength and structural integrity of the housing 4 which gets weakened due to the presence of the apertures 12. Thus, while preferably the housing 4 has three apertures 12 associated with three slots 66, other numbers of apertures 12 and slots 66 are also possible for example two or four.

[0104] As in previous examples, each aperture 12 may comprise a removable cover 74, which can help prevent silting and foreign body ingress into the housing 4 until access is required. The removeable cover 74 also provides rigidity and structural support to the housing 4 during deployment and recovery of the connection node 2, as well as providing protection to the stowed connection socket 10 and associated components.

[0105] Figure 11a shows the housing 4 with the cover 74 of the uppermost aperture 12 (e.g. at 0 degrees) removed, allowing the connection socket 10 to be accessed via this aperture 12 (as shown in Figure 11 b). Figure 11 b shows the covers 74 on the remaining two apertures (e.g. at 120 degrees and 240 degrees).

[0106] In a similar manner, Figures 13a and 13b relate to the multi-axis joint 60 when the cover 74 at the lower right position (e.g. 120 degrees) is removed. Figure 13a shows a front-on view of the multi-axis joint 60 with the cover 74 to be removed identified in shading in order to allow the connection socket 10 to be accessed via its corresponding aperture 12 (as shown in Figure 13b). Figures 13a and 13b show the covers 74 on the remaining two apertures (e.g. at 0 degrees and 240 degrees).

[0107] Similarly, Figures 14a and 14b relate to the multi-axis joint 60 when the cover 74 at the lower left position (e.g. 240 degrees) is removed. Figure 14a shows a fronton view of the multi-axis joint 60 with the cover 74 to be removed identified in shading in order to allow the connection socket 10 to be accessed via its corresponding aperture 12 (as shown in Figure 14b). Figures 14a and 14b show the covers 74 on the remaining two apertures (e.g. at 0 degrees and 120 degrees). The multi-axis joint 60 comprises several locking features which help improve the multi-axis joint 60. A first locking mechanism 75 secures each aperture 12 to the housing 4 to reduce the likelihood of the apertures 12 accidentally becoming dislodged. A second locking mechanism 102 secures the position of the connection socket 10 in use, to provide a more stable connection point between the connection socket 10 and any additional cables or components. These locking mechanisms will be described in turn, starting with the first locking mechanism 75.

[0108] As can be seen at least in Figures 15 and 16, each cover 74 comprises a first locking mechanism 75 which includes a rotatable locking element 76 having a receiving slot 78 that can be used to rotate the locking element 76 between a locked position and an unlocked position. The locking element 76 can be actuated by a locking key 82 having protrusion 84 which is sized and shaped to fit into the receiving slot 78. The protrusion 84 can be inserted into the receiving slot 78, as shown in Figure 16, and then the locking key 82 can be used to turn the locking element 76 to lock and unlock the cover 74 from the housing 4. A handle portion 80 on the cover 74 can be used to facilitate removal of the cover 74 from the housing 4 when the cover 74 is unlocked from the housing 4.

[0109] The locked position of the first locking mechanism 75 is shown in more detail in Figures 17a (showing a cross-section through the side of the first locking mechanism 75) and 17b (showing a view from the underside of the first locking mechanism 75). The underside of the locking element 76, shown in Figure 17b, comprises a plurality of uniformly spaced cam surfaces 86. Each cam 86 comprises a steep side 88 and a gentle sloped side 90.

[0110] A plurality of locking pins 92 are positioned on opposite sides of the locking element 76 such that the locking element 76 is located between the locking pins 92. The locking pins 92 are biased towards the locking element using a biasing element 94, such as a spring, such that a first end 96 of each locking pin 92 abuts a part of the cam 86 of the locking element 76. Specifically, when the locking element 76 is in the locked position as shown in Figures 17a and 17b, the first ends 96 of the locking pins 92 abut the outermost edge of the sloped sides 90 of the cam 86. In this position, second ends 98 of the locking pins 92 protrude through corresponding holes 100 in the cover 74, engaging part of the housing 4. The second ends 98 of the locking pins 92 retain the cover 74 in place. Thus, in the locked position, locking pins 92 of the locking mechanism 75 engage with the housing 4 to lock the cover 74 in place.

[0111] In order to unlock the cover 74 from the housing 4, the locking element is rotated using the locking key 82, for example in the direction shown by arrow A in Figure 17b. In this example, a rotation of 90 degrees anticlockwise is shown in order to move the locking element 76 from the locked position to the unlocked position shown in Figures 18a and 18b.

[0112] As the locking element 76 is rotated, due to the biasing element 94 acting on the locking pins 92, the first ends 96 of the locking pins 92 will ride along the sloped sides 90 of the cam 86 until the first ends 96 of the locking pins 92 abut the steep sides 88 of the cam 86 and further rotation of the locking element 76 is prevented.

[0113] When the first ends 96 of the locking pins 92 abut the steep sides 88 of the cam 86 the second ends 98 of the locking pins 92 no longer protrude through their corresponding holes 100 in the cover 74. In this configuration, the cover 74 can be removed from the housing 4 (as shown in Figure 19) as the locking pins 92 are no longer retaining the cover 74 in place, and so the cover 74 is unlocked. Thus, in the unlocked position the locking pins 92 of the locking mechanism 75 do not engage with the housing 4.

[0114] The design of the locking element 76 provides a simple and effective locking mechanism in which the locking pins 92 to easily slide over the gentle sloped slide 90 and lock against the steep side 88. The locking element 76 is machined to provide a plurality of rotating cam surfaces 86 which the biased locking pins 92 follows as the locking element 76 is rotated. The first ends 96 of the locking pins 92 are shaped to match the profile of the cam 86. In particular, the first ends 96 of the locking pins 92 are hemispherical in shape such that they match the profile of the cam surface within locking element 76.

[0115] In the illustrated example, two locking pins 92 and two cams 86 are shown. To relock the locking element 76 from the unlocked position, the locking element 76 is simply rotated in the opposite direction (e.g. in the clockwise direction) until the locking pins 92 engage the housing again.

[0116] As mentioned above, the second locking mechanism 102 secures the position of the connection socket 10 after the connection socket 10 has been removed from the housing 4 via an aperture 12. The second locking mechanism 102 has an unlocked position, shown in Figures 20a and 20b, in which the connection socket 10 can move via the multi-axis joint 60 and a locked position, shown in at least in Figures 23a and 23b, in which the connection socket 10 is fixed in place along one of the slots 66 in the multi-axis joint 60.

[0117] In more detail, the second locking mechanism 102 comprises a latch 104 including a load stop 106 and a leaf 108. A latch 104 is provided for each slot 66 in the multiaxis joint 60, and so there are the same number of latches 104 in the second locking mechanism 102 as there are slots 66 in the joint 60. In the illustrated example having three slots 66, three latches 104 are provided.

[0118] The leaf 108 is attached to the base 62 at a first end 107 while a second end 109 of the leaf 108 is free (as best seen In Figure 21). The leaf 108 is made of a material which allows the leaf 108 to flex towards the load stop 106 when a force is applied to the second end 109 and return to its original position when the force is removed. In this way, the leaf 108 behaves as a leaf spring. The load stop 106, also attached to the base 62, prevents over loading of the leaf 18.

[0119] Each leaf 108 comprises a ridge 110 configured to be engaged by a lip 112 that extends around the circumference of the disc portion 64. In particular, with reference to Figures 20a and 20b, when the connection socket 10 is desired for use, the socket support 44 is moved along one of the slots 66 to remove the connection socket 10 from the housing 4. As the socket support 44 travels along the slot 66, the lip 112 of the disc portion 64 travels along part of the length of the leaf 108 from the first end 107 towards the second end 109, as shown in Figure 21. At this point, lip 112 has not yet reached the ridge 110 and so the socket support 44 can continue to move along the slot 66 in both directions. Since the socket support 44, and therefore the connection socket 10, can still move the second locking mechanism 102 and latch 104 are in the unlocked position.

[0120] Looking at Figure 22, when the socket support 44 has moved sufficiently far along the length of the slot 66, the lip 112 of the disc portion 64 will have travelled sufficiently far along the length of the leaf 108 such that the lip 112 engages the ridge 110, as shown in Figures 23a and 23b. In this configuration, movement of the socket support 44 in the opposite direction towards the center of the joint 60 is prevented and so the connection socket is retained in position by the engagement between the lip 112 and the ridge 110. The second locking mechanism 102 and the latch 104 are now in the locked position. In this way, the connection socket 10 is locked in place when part of the multi-axis joint 60 engages part of the second locking mechanism 102. The locked position is shown again in Figures 24a and 24b. In this locked position, additional cables or components can be connected to and disconnected from the connection socket 10 as needed.

[0121] To stow the connection socket 10, when not in use, the second locking mechanism 102 first needs to be unlocked so that the socket support 44 can travel back along the slots 66 and the connection socket 10 returned to the housing 4.

[0122] As shown in Figure 26, to unlock the second locking mechanism 102, a force is applied to the second end 109 of the leaf which causes the lip 112 to disengage from the ridge 110. When the disc portion 64 is no longer engaging any part of the latch 104, the lip 112 is free to travel back along the length of the leaf 108 towards the first end 107, as shown in Figure 27. The socket support 44 can move back along the slot 66, returning the connection socket 10 to the housing 4 as shown in Figure 28. The cover 74 of the aperture can be replaced, as shown in Figure 29.

[0123] The process of deploying and stowing the connection socket 10, including operation of the first and second locking mechanism, can be summarized as follows.

[0124] To deploy the connection socket 10, access to the appropriate aperture 12 (determined based on the orientation of the connection node 2) must be gained by removing its cover 74. This is achieved by inserting the locking key 82 and rotating the locking element 76 which allows biased locking pins 92 to disengage a portion of the housing 4. The cover 74 can then be lifted, using the handle portion 80 if necessary, away from the housing 4 to expose the connection socket 10 through the aperture 12. The connection socket 10 can be gripped and manipulated in a manner which causes rotation about the multi-axis joint 60. The socket support 44 slides along the appropriate slot 66 until the latch 104 is engaged and the second locking mechanism 102 is in the locked state. The connection socket 10 is now in its operation state and external subsea connections to equipment or cable infrastructure can be made.

[0125] To return the connection socket 10 to its stowed configuration, the second locking mechanism 102 is unlocked by disengaging the latch 104, allowing the connection socket 10 to rotate about the multi-axis joint back into the housing 4. Once the connection socket 10 has returned to the housing 4, the cover 74 can be replaced and locked into position by rotating the locking element 76, using the locking key 82, which causes the locking pins 92 to engage the housing 4.

[0126] Operation of the locking key 82, removal and replacement of the cover 74, and manipulation of the connection socket 10 are carried out by an ROV.

[0127] In some examples, a loop-back connector 120 is provided with the connection node 2, which is configured to mate with the connection socket 10 and be stored within the housing 4 when the connection socket 10 is not in use. Before use of the connection socket 10, the loop-back connector 120 can be removed by the ROV and subsequently replaced after use.

Claims

Claims1 . A connection node for a subsea cable, the connection node comprising: a housing arranged between first and second connection ends; a connection socket arranged to be stored within the housing; at least one aperture located within the housing configured to allow the connection socket to be accessed via the aperture; wherein the connection node is configured to be connected in-line with a subsea cable via the first and second connection ends; wherein the connection node further comprises a multi-axis joint configured to allow multi-directional movement of the connection socket.

2. The connection node according to claim 1 wherein the connection socket is a wet-mate connector.

3. The connection node according to claim 1 or claim 2 wherein the connection socket comprises a female connecting portion.

4. The connection node according to claim 1 or claim 2 wherein the connection socket comprises a male connecting portion.

5. The connection node according to any preceding claim further comprising an optical fibre pair and power conductor, wherein the connection socket is configured to communicate with a subsea cable via the optical fibre pair and power conductor.

6. The connection node according to claim 5 wherein the optical fibre pair and power conductor are located within a hose.7 The connection node according to claim 6 wherein the hose is a flexible hose.

8. The connection node according to claim 6 or claim 7 wherein the hose is an oil- filled hose.

9. The connection node according to any of claims 5 to 8 further comprising a breakout housing, wherein the breakout housing is configured to allow the optical fibre pair and power conductor to be broken out from a subsea cable and form a connection with the connection socket.

10. The connection node according to claim 9 wherein the optical fibre pair and power conductor are routed through the breakout housing via a flexible link.11 . The connection node according to claim 10 wherein the flexible link is located between a first bulkhead and a second bulkhead within the breakout housing.

12. The connection node according to any of claims 9 to 11 wherein the breakout housing is arranged between the housing and the first connection end of the connection node.

13. The connection node according to any preceding claim where the first and second connection ends are configured for connection with first and second universal joints of a subsea cable.

14. The connection node according to any preceding claim wherein the housing comprises a plurality of apertures, and wherein each aperture of the plurality of apertures is configured to allow the connection socket to be accessed via the aperture.

15. The connection node according to any preceding claim wherein the at least one aperture comprises a cover.

16. The connection node according to claim 15 wherein the cover is releasably attached to the housing.

17. The connection node according to any preceding claims wherein the housing comprises a dummy connection point configured to receive the connection socket.

18. The connection node according to any preceding claim wherein the multi-axis joint is a ball and socket style joint, preferably configured to allow movement in three distinct directions.

19. The connection node according to any preceding claim wherein the multi-axis joint comprises a frame having at least one slot arranged to allow movement of the connection socket along the slot.

20. The connection node according to claim 19 further comprising a socket support configured to support the connection socket and further configured to move along the slot to cause movement of the connection socket.

21. The connection node according to any of claims 19 or 20 wherein the multiaxis joint further comprises a disc portion having a curved surfaced complementary to a curved outer surface of the frame.

22. The connection node according to claim 22 wherein the socket support is configured to pass through a hole in the disc portion and abut a portion of the disc portion.

23. The connection node according to any of claims 19 to 22 wherein the frame comprises a plurality of slots, preferably three slots, and the plurality of slots are equally spaced apart from each other around the frame.

24. The connection node according to any of claims 19 to 23 wherein further comprising a second locking mechanism configured to prevent movement of the connection socket in a locked position and allow movement of the connection socket in an unlocked position.

25. The connection node according to claim 24 wherein the second locking mechanism comprises a latch configured to engage with a portion of the multi-axis joint in the locked position.

26. The connection node according to claim 25 wherein the latch comprises a ridge configured to engage with a lip on the disc portion when the second locking mechanism is in the locked position.

27. The connection node according to any of claims 25 or 26 wherein the latch comprises a release configured to disengage the latch from the portion of the multi-axis joint.

28. The connection node according to claim 27 wherein the release is a leaf spring.

29. The connection node according to claim 28 wherein the leaf spring comprises a bias such that the second locking mechanism is biased in the locked position.

30. The connection node according to any of claims 16 to 29 wherein the cover comprises a first locking mechanism configured to prevent the cover from being removed from the housing when the first locking mechanism is in a locked position and allow the cover to be removed from the housing when the first locking mechanism is in an unlocked position.

31. The connection node according to claim 30 wherein the first locking mechanism comprises a rotatable locking element configured to adjust the first locking mechanism between the locked and unlocked positions.

32. The connection node according to claim 31 wherein the rotatable locking element comprises a receiving slot configured to receive a locking key.

33. The connection node according to any of claims 30 to 32 wherein the first locking mechanism comprises at least one locking pin configured to engage with a portion of the housing when the first locking mechanism is in the locked position.

34. The connection node according to any of claims 30 to 33 wherein the rotatable locking element comprises at least one cam profile comprising a steep side and a sloped side.

35. The connection node according to claim 34 wherein the at least one locking pin is configured to engage the at least one cam profile when the first locking mechanism is in the unlocked position.

36. The connection node according to any of claims 30 to 35 wherein the first locking mechanism comprises a biasing element configured to bias the first locking mechanism in the unlocked position.

37. The connection node according to claim 36 wherein the biasing element is configured to bias the locking pin towards an unlocked position of the locking pin.

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