Self-latching locking device for mating with a connecting structure, and locking system and methods for using it

Abstract

The disclosure relates to a self-latching locking device (18) for mating with a connecting structure, the locking device comprises: - a body member (15) with a receptacle end (35) comprising at least two parallel end members (35', 35") each comprising a locking aperture (42,43) - a framed member (22) at least partly surrounding, and attached to, the body member (15), wherein the framed member (22) comprises an aligning receptacle (40) adapted to receive and align a portion of connecting structure (10,14) to be locked, - a locking latch (52) pivotably attached to the framed member (22) or the body member (15) and adapted to intervene in the first and second locking apertures (42,43). The disclosure further relates to a locking system for locking at least a line to a connecting structure, a method for connecting a mooring element (11) to a connecting structure (10, 14), and a method for disconnecting a mooring element (11) and a connecting structure (10, 14).

Description

[0001]Title: Self-Latching Mooring Connector Technical field The present disclosure relates to a self-latching locking device for mating with a connecting structure and a locking system for locking at least a line to a connecting structure. More specifically, the disclosure relates to a self-latching locking device for mating with a connecting structure and a locking system for locking at least a line to a connecting structure as defined in the introductory parts of the independent claims. Background Renewable energy has a growing interest in the industry. For offshore energy harvesting main focus today is on wind energy, where wind turbines are placed on either bottom-fixed structures or on moored floating units. To obtain enough capacity of produced energy several of these structures / units are installed in the same area and connected together forming a wind farm / park. Cost for these offshore farms, and especially farms comprising moored floating units, is in general higher than onshore farms. To secure that offshore wind farms comprising moored floating units are competitive the technology must be optimized. This involves cost reduction in all areas, including cost for goods, cost for transport and cost for offshore installation. A moored floating device has typically three or more mooring lines, where each mooring line is connected to the floating unit at one end and to an anchor at the other end. The connection to the anchor depends on the anchor type. For some anchor types, such as suction anchors, the optimum connection point for the mooring line is below the mudline. This typically requires a chain segment at the lower end of the mooring line, because chain is more robust for interfacing with the soil than alternatives such as steel wire rope segments and synthetic rope segments. However, to reduce cost for the mooring system it is preferred to reduce the amount of chain, and if the chain towards the anchor is shorter than the water depth a subsea connector is required between the upper end of the mentioned chain and the next mooring line segment, which can be another chain segment, a steel wire rope segment, a synthetic rope segment or any other type of structures or components forming a part of the complete mooring line assembly. For suction anchors it is common to install the anchor with a very short chain segment, where the lower end is connected to an anchor padeye below the mudline and the upper end is temporary hung-off at the top of the anchor. This chain segment, which is later referred to as the anchor chain (or lower chain), is installed together with the anchor itself. The rest of the mooring line is then typically installed later by using an ROV (Remotely Operated Vehicle) operated H-link. The time to connect the mooring line to the anchor chain using the ROV operated H-link may take significant time, which is time that is highly beneficial to reduce when many mooring lines needs be installed during the same weather window or in same season. The invention therefore relates to a subsea mooring connector which requires minimal use of ROV, and with a self- latching locking device for efficient connection. In addition to the traditional ROV operated H-links other connector types are also available in the market. Examples of such prior arts are disclosed in patent documents WO2013093455, CA2899683, US10035568, US10883571, GB2555503 and US20230127233. A problem with the solutions of the prior art is that the traditional ROV operated H-links are no self-latching devices. There is thus a need for improved solution over the prior art that self-aligns and self-latches. Summary It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above mentioned problem. According to a first aspect there is provided a self-latching locking device for mating with a connecting structure, the locking device comprises: - a body member with a receptacle end comprising at least two parallel end members each comprising a locking aperture - a framed member at least partly surrounding, and attached to, the body member, wherein the framed member comprises an aligning receptacle adapted to receive and align a portion of connecting structure to be locked, - a locking latch pivotably attached to the framed member or the body member and adapted to intervene in the first and second locking apertures. According to some embodiments, the locking latch is rotatable around axis through hinge means on the framed member or the body member, wherein the axis is lateral offset a distance from a longitudinal centerline axis going through two parallel end members. According to some embodiments, the locking latch the locking comprises two contact surfaces adapted to being in contact with respective first and second corresponding contact surfaces in the perimeter of the first and second locking apertures. According to some embodiments, the locking latch comprises a latching body comprising: - a first contact surface adapted to be in locking contact with the first corresponding contact surface of the first locking aperture, wherein the a first contact surface and first corresponding contact surface DUH^DOLJQHG^DQG^DW^DQ^DQJOH^Į^WR^DQ^D[LV^^DQG^^- a second contact surface adapted to be in locking contact with the second corresponding contact surface of the second locking aperture, wherein the a second contact surface and second corresponding contact surface are aligned and at an DQJOH^ǃ^WR^DQ^D[LV^^DQG^^- a link contact surface on and opposite side of latching body from the first and second contact surface, wherein the link contact surface is adapted to contact and receive the load of the chain link or a chain to be locked, wherein the opposite angled contact surfaces are adapted to compress the two parallel ends of the body member when the load from a connecting structure acts on the locking latch. According to some embodiments, the locking latch further comprises a joining structure between the latching body and the hinge means distancing the latching body from the hinge means at least a radial distance from the axis. According to some embodiments, the latching body and the joining means together has a center of mass providing a rotational moment around the hinge means. According to some embodiments, a tension member is connected between the joining structure and the attachment structure or main body at the other end. According to some embodiments, the body member comprises at least a passive end adapted to receive fastening means for a mooring element. According to some embodiments, the locking latch further comprises a counterweight assembly the locking comprises a lever arm protruding from the locking latch, or parts thereof, and a weight element at an distal end of the lever arm. According to a second aspect there is provided a locking system for locking at least a line to a connecting structure, the system comprising the locking device according to the first aspect, a mooring element attached to the first passive end of the body member, and a connecting structure adapted to be locked to the self-latching locking device. According to some embodiments of the second aspect, the body member comprises at least a passive end to receive fastening means for a separate HOHPHQW^^ZKHUHLQ^WKH^PRRULQJ^HOHPHQW^FDQ^EH^DQ\^RQH^RI^^D^FKDLQ^^VWHHO^ wire rope, a socket for a steel wire rope, a synthetic rope, a thimble for a synthetic rope, a shackle, a mooring line buoyancy element, a mooring line clump weight, a rod structure of any kind, a chain, a chain element. According to some embodiments of the second aspect, the connecting structure can be chain link, the end of a chain, or a structure with a comparable interface as a chain link, such as an arched or bent rod or wire. According to some embodiments of the second aspect, the system further comprises a release tool. According to some embodiments of the second aspect, the release tool comprises - a connection structure, adapted to be attached to the body PHPEHU^RU^DWWDFKPHQW^VWUXFWXUH^^DQG^^- a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel and a piston rod, and / or a screw and a gear arrangement, the piston rod and / or a screw and a gear arrangement is arranged to forcibly move the locking device from a closed position and into an open position. According to further aspects, it is provided a method for connection a mooring element to a connecting structure, wherein the method the locking comprises the steps of: - providing a mooring element with the locking device according to any one of the - lower said locking device onto a portion of the connecting structure, - align, if the connecting structure is not aligned with the receptacle end, the connecting structure and receptacle end by the aligning receptacle, - mate the connecting structure and the receptacle end until the locking latch intervenes between the connecting structure and the receptacle end and locks into contact with the first and second inclined contact surface. According to further aspects, it is provided a method for disconnection a mooring element and connecting structure connected by a locking device, the method comprising the steps of: - releasing tension from the connecting structure and / or the locking device, - move the locking latch from its locked position to its unlocked position using an unlocking means, - removing the connecting structure from the receptacle end. According to some embodiments of the method for disconnection, the unlocking means is a counterweight assembly comprising a lever arm protruding from the locking latch, or parts thereof, and a weight element at an distal end of the lever arm and / or an release tool comprising connection structure, adapted to be attached to the body member or attachment structure, and a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel and a piston rod, the piston rod is arranged to forcibly move the locking device from a closed position and into an open position. According to some embodiments of the method for disconnection, the unlocking means is / are operated and / or actuated by an ROV. Effects and features of the second aspect are to a large extent analogous to those described above in connection with the first aspect. Embodiments mentioned in relation to the first aspect are largely compatible with the second aspect. The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure. Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps. Brief description of the figures The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings. Fig. 1 illustrates a typical general arrangement of a turret moored ship- shaped floater with its mooring lines, side view Fig. 2 illustrates a typical general arrangement of a spread-moored floating wind turbine with its mooring lines, perspective view Fig. 3 illustrates a typical composition of a mooring leg comprising a pile anchor and chain and steel wire rope segments Fig. 4 illustrates a typical composition of a mooring leg comprising a suction anchor and chain and synthetic rope segments Fig. 5 illustrates a typical suction anchor with a pre-installed anchor chain hung-off at the top of the anchor during anchor installation Fig. 6 illustrates two typical ROV operated H-links for connection of an upper mooring line segment to an anchor chain hung-off at the top of a pre-installed suction anchor Fig.7a-d illustrates a locking device in profile with different intersection views. Fig.8 illustrates an exploded view of invention locking device Fig.9a illustrates a locking device in use after connection to anchor chain and after lifted off hang-off structure on anchor Fig.9b illustrates a locking device in an intersected view in use after connection to anchor chain and after lifted off hang-off structure on anchor Fig.9c illustrates a locking device in an intersected view in use after connection to anchor chain and after lifted off hang-off structure on anchor Fig.10 shows an upper mooring line with the invention connected to the lower end when approaching an anchor chain hung-off at the top of a pre-installed suction anchor Fig.11 illustrates the main steps during mating of the invention with an anchor chain hung-off at the top of a pre-installed suction anchor, perspective view Fig.12 illustrates the main steps during mating of the invention with an anchor chain hung-off at the top of a pre-installed suction anchor, section view Fig.13 illustrates disconnection of the invention from a chain link, alternative with hydraulic cylinder device Fig.14 illustrates disconnection of the invention from a chain link, alternative with a weight on a lever arm Fig.15 shows two alternative designs of main body of invention Fig.16 illustrates alternatives, including chain link, of the structure to mate with the invention Detailed description of preferred embodiments Preferred embodiments of the invention are described below with reference to the attached figures in which preferred example embodiments of the disclosure are shown. Note that the description of the invention refers mainly to an embodiment where the active side of the device and system shall connect to a vertically aligned chain link, and where the passive side of the invention is also attached to a chain link. These interfacing parts do not provide a limitation to the invention, and other examples of the embodiment and interfacing parts are therefore described at the end. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person. Passive side of the invention refers to the side where the mooring line is pre- connected to the invention, typically manually connected, before the device with the mooring line is over-boarded from the installation vessel. The active side is the side where the invention is provided with the self-latching device for connection to a mating structure located below the sea surface, typically at or close to the seabed. Figs. 1-2 illustrates typical mooring system arrangement, where Fig. 1 refers to a mooring system for a ship-shaped vessel and Fig. 2 refers to a mooring system for a floating wind turbine. In these figures the floating unit 1 at the sea surface 2 is moored to the seabed 3 with mooring lines 4 connected to the floating unit 1 at the upper end and to anchors 5 at the lower end. In Fig. 2 also power cables 6 are illustrated. Types of floating units can be semi-submersible platforms, SPAR platforms, ship-shaped units or barges for oil & gas or energy industry, such as floating production and storage units, floating storage units, floating liquified natural gas production vessel, floating storage and re-gasification units, floating nuclear power plants, floating gas power stations, etc.. Figs. 3-4 illustrates typical arrangements of a mooring leg. The mooring leg comprises an anchor 5 and a mooring line 4. The mooring line 4 is in Fig. 3 connected to a driven pile anchor 8 with an anchor chain 10. The anchor chain 10 is at the upper end connected to a mooring element 11, (illustrated as another chain segment) via a connecting element 7. This connecting element can be a triplate, H-link, or similar. The mooring element 11 is further connected to a steel wire rope, which is then connected to the floating unit 1. Fig. 4 shows a similar arrangement, but in this case the anchor is a suction anchor 9 connected to an anchor chain 10, and further to the mooring element 11, illustrated as another chain segment , via a connecting element 7. Connecting element 7 is in this arrangement typically an ROV operated H-link 12. The mooring line 4 further comprises synthetic rope segments and yet another chain segment before connected to the floating unit 1 at the upper end. Fig. 5b shows a typical assembly of a suction anchor 9 with a pre-installed connecting structure 10, 14 such as an anchor chain 10 with an uppermost chain link 14. This reflects the lower part of the mooring leg arrangement shown in Fig.4. In this embodiment the anchor chain is hung-off at the top of the anchor to a hang-off structure 13 with the uppermost chain link 14 resting on the hang-off structure. The uppermost chain link 14 is vertically aligned, i.e. the length-axis of the chain link is vertical, or close to vertical. Fig. 5a shows the same as Fig. 5b, however the connector 12 with the mooring element 11 (chain) connected to the passive side has mated with the uppermost chain link 14 of anchor chain 10. After the mating of connector 12 to the anchor chain the anchor chain will be lifted off the hang-off structure 13 and pulled into the seabed. Fig. 6 shows two typical ROV operated H-links. Both of them comprise an H- link body 15 and a permanent or detachable structure 17 for guiding and installation of an ROV operated pin, where the pin locks the connector 12 to the chain link 14. When the connector 12 has been lowered over the chain link 14 and is resting on the hang-off structure 13 together with the chain link 14 the ROV pushes the pin through the chain link 14 and locks it in place. The ROV then typically removes the structure 17 (if detachable) and brings it to surface, but it can also be designed as a permanent structure. The hang-off structure 13 may also have guideposts 16 or any other guide arrangement for easy docking of the connector 12 onto the chain link 14. Fig. 7 shows the locking device 18. The device may comprises three main parts, i.e. the body member 15, the locking segment 19 and the framed member 22. In Fig. 7a the active side with a receptacle end 35 adapted for receiving and mating has mated with the uppermost chain link 14 of the anchor chain 10. The passive side 34 of the locking device 18is connected to the upper chain (mooring element 11). Fig. 7b and Fig. 7d show cross section views of the invention where the locking segment 19 is in locked position 21. Fig. 7c shows a side view of the invention just with the locking segment 19 in open position 20. Fig. 8 provides an exploded view of the locking device 18. The invention comprises three main parts, i.e. the body 15, the locking segment 19 and the framed member 22. The body 15 is very similar to the H-link body shown in Fig.6, expect that the interfacing part with the locking segment 19 is different than the interfacing part for the pin of the H-link. The upper chain (mooring element 11) is connected to the passive end 34 of the locking device 18 via the pin 25. The uppermost link 14 of the anchor chain 10 is connected to the receptacle end 35 of the locking device 18 via the locking device 19. The latching body 19 is fixed to a joining structure 23. The joining structure 23 is further connected to the framed member 22 via a hinge 24. This allows the latching body 19 to rotate relative the framed member 22 and the main body 15 around a rotation axis 51 defined by the axle of the hinge means 24. The latching body 19 will then in an open position 20 not interfere / lock the chain link 14. In a closed position 21 the latching body 19 will lock the chain link 14 to the main body 15. The joining structure 23 might comprise feet 56 with a weight element and / or a protrusion in direction towards the centerline from the hinge 24, such that either the weight alone provides rotational force to aid in the locking of the latching body 19 , and / or the protrusion can protrude a distance inside the aligning receptacle 40, such that when a connecting structure 10,14 or parts thereof, enters the aligning receptacle 40, the connecting structure 10,14 or parts thereof, pushes on the protrusion of the feet 23 and rotates the locking latch 52 towards locking. The opening of the latching body 19 is by physical contact between the locking device and the chain link 14 during lowering of the locking device 18 onto the chain link 14. Lower part of the framed member 22 is a guide structure with an aligning receptacle 40. This guide structure rotates and aligns the locking device 18 relative the chain link 14 such that the locking device gets positioned correctly relative the chain link 14. The weight of the locking segment 19 is much less than the total weight of the locking device 18. Hence, the weight of the invention will secure that the locking device opens during the lowering process of the invention onto the chain link 14. When the upper part of the chain link 14 has passed the open locking segment 19 the locking segment will rotate back into the main body 15 into the inner opening of the chain link and thus prevent the chain link from releasing from the locking device 18. The locking of the latching body 19 is either by gravity (the center of gravity of the locking device including the joining structure is always on the same side relative the axis 51 going through the hinge 24, by tension member 37, or by the combination of the two. The tension member 37 can be any type of member adapted to apply a restoring force on the locking latch 52, such as a spring or the like. The purpose of the tension member 37 is to secure that the locking device closes on its own or automatically from an open position, at which the effect of gravity is at the lowest, when a connecting structure 10, 14 is introduced into the receptacle end 35 of the locking device 18 for mating. The tension member 37 is in this embodiment (Fig. 8) shown as a rubber string fixed to both a connection structure 39 on the joining structure 23 and to connection structures 38 on the attachment structure. The connection structure 39 is in Fig. 8 shown as a small horizontal tube, inside which the rubber string can be routed / treaded. As shown in Fig. 8 the locking device 19 is a non-circular structure, and thus very different from the pin 25. One of the functions of the non- circular shape of the latching body 19 and the non-circular openings 42 and 43 in the main body 15 is to prevent any rotation of the locking device around its longitudinal axis 45 when in closed position. The longitudinal axis 45 is perpendicular to the axis 44 of the main body 15. The axis 44 is parallel to a centerline CL centered between the two parallel end members 35’, 35’’. Fig. 9a illustrates the locking device 18 after it has been connected to the uppermost chain link 14 of the anchor chain 10, and just after the entire arrangement has been lifted off the hang-off structure 13. Fig. 9b illustrates the locking device 18 with the interfacing surfaces 41 and 41’ between the latching body 19 and the main body 15. The interfacing surfaces are preferably inclined relative the longitudinal axis 45 for locking device in closed position. These inclined surfaces will prevent any movements along the axis 45 when the chain link 14 pushes on the locking device with a force F. As seen in Fig. 9b, the force F is absorbed by the interfacing surfaces 41 and 41’, wherein each of the interfacing surfaces 41 and 41’ withstands a force of about F / 2. As the surfaces are inclined, the forces of about F / 2 will force the ends 35’, 35’’ towards each other. A protrusion or lump 46 may protrude from the latching body 19 on (see Fig. 8) and it has at least two main functions. The first is to provide a center of gravity of the latching body 19 and joining structure 23 which is suitable for self-locking by gravity, and the second is to provide a secondary lock (in addition to the inclined surfaces) against sideways movement of the locking device. The main body 15, the latching body 19 with the joining structure 23 and axle 24 as shown in the embodiment in Fig. 8 and Fig. 9 are arranged such that after the locking device 18 has connected to the chain link 14 any compression in the system leading to the invention pushing on the chain link 14 it is not possible to push the locking device into open position, i.e. unintentional opening of the locking device is basically impossible. As seen in Fig. 8, the locking latch 52 is illustrated comprising a latching body 19 comprising a first contact surface 41 adapted to be in locking contact with the first corresponding contact surface 54 of the first locking aperture 42, wherein the a first contact surface and first corresponding contact surface are DOLJQHG^DQG^DW^DQ^DQJOH^Į^(see Fig. 9c) WR^DQ^D[LV^^^^^DQG^^- a second contact surface 41’ adapted to be in locking contact with the second corresponding contact surface 55 of the second locking aperture 43, wherein the a second contact surface and second corresponding contact surface are aligned and at DQ^DQJOH^ǃ^^VHH^Fig. 9c) to an axis 51^^DQG^^- a link contact surface 53 on and opposite side of latching body 19 from the first and second contact surface, wherein the link contact surface 53 is adapted to contact and receive the load of the connecting structure 10,14 or a chain to be locked, wherein the opposite angled contact surfaces are adapted to compress the two parallel ends 35,35’ of the body member 15 when the load from a connecting structure 10,14 acts on the locking latch 52. Fig. 9c illustrates the locking device 18 that the locking latch 52 is rotatable around axis 51 through hinge means 24 on the framed member 22 or the body member 15, wherein the axis 51 is lateral offset a distance D1 from a longitudinal centerline axis 44 going through two parallel end members 35’,35’’. Thereby, when the locking device 18 is mating, the angled first and second corresponding contact surfaces 54, 55 of the first and second locking apertures 42, 43 aligns with the first and second contact surfaces 41, 41’ of the latching body 19, as the respective angles are aligned. It should be understood that the angles Į and ǃ may and may not be equal. The operation of the locking device 18 during connection to the anchor chain is further illustrated in Figs.10, 11 and 12. Fig. 10 shows the installed anchor structure 9 with the pre-installed anchor chain 10, which is connected to an anchor padeye at the lower end and hung- off in the hang-off structure 13 at the upper end. The lower end of the rest of the mooring line 4 comprises a mooring element 11, such as a chain segment with the locking device 18 connected at the lower end. Fig. 10b is a close up of Fig.10a. The figure shows the situation just before the locking device 18 is lowered onto the chain link 14. A Remotely Operated Vehicle (ROV) 26 may be required to rotate the locking device 18 around its longitudinal axis 44 such that it lands correctly onto the chain link 14. However, the framed member22 has a aligning receptacle 40 which will rotate the locking device 18 by itself in most scenarios, i.e. without the help of an ROV. The aligning receptacle 40 is illustrated as a framed part at least partly surrounding and protruding the receptacle end 35 of the body member 15 with a first set two parallel sides protruding further than a second set parallel sides, as illustrated in Fig. 8. The aligning receptacle 40 may thereby proved a set or two pairs of shoulders for a portion of connecting structure 10, 14 to abut, and thus align by rotation, against. Both Fig.11 and Fig.12 show the connection process step-by-step. Fig. 11 provides a perspective view while Fig. 12 shows a cross sectional view of the device and system and the position of the locking device for the different time instances (steps). Fig. 11a and Fig. 12a show the situation just before the locking device 18 is lowered onto the chain link 14 – the first step. Fig.11i and Fig. 12j show the situation after the connection is completed and the anchor chain 10 with the chain link 14 is fully hanging in the invention, i.e. the anchor chain 10 with the chain link 14 is no more in contact with the hang-off structure 13 – the last step. The figures in-between show different time instants on the way from the first step to the last step. Fig. 12 shows specifically how the latching body 19 is pushed open by the chain link 14 when the connecting structure 10, 14 is introduced into the , and how it falls into locked position when the chain link 14 has sufficiently moved into the main body member 15. As can be seen in Fig. 12a, the locking latch 52 is in the locked state, and in Fig.12b, the chain link 14 enters the aligning receptacle 40 and in between the two parallel end members 35,35’, slightly pushes the locking latch 52 upwards and rotating it around hinge 24. As the chain link 14 enters the locking device 18, the locking latch 52 further opens until it is in a maximum rotated and open state, as illustrated in Fig. 12g. In Figs. 12a to 12f, the chain link 14 interacts with the protrusion 46. Fig.12h illustrates that the uppermost part of the chain link 14 is passed the locking latch 52, and the locking latch 52 closes and positions itself in-between the chain link 14. At this stage, the second chain link of the chain 10 might interact with the feet 56 of the locking latch 52 to aid in the closing. Fig. 12j illustrates the chain link 14 fully resting and contacting he link contact surface 53 is adapted to contact and receive the load of the connecting structure 10,14. After the last step in Fig. 11 and Fig. 12 the rest of the mooring line 4 will be installed, and the locking device 18 will either be pulled into the soil, rest on the soil or be in the water column between the seabed 3 and the sea surface 2. Disconnection of the mooring line 4 at the locking device 18 is not a planned activity. Main scenario requiring disconnection is if the mooring line 4 has been damaged such that the mooring line must be separated at the location of the locking device 18. In many cases a repair of a mooring line can be conducted without disconnecting at the point of the locking device 18. However, disconnection can be done with the proper equipment or method, as disclosed herein. Fig.13 and Fig.14 show two alternatives for disconnection. In Fig.13 a release tool 27 comprising a connection structure 28 and a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel 29 and a piston rod 30. The connection structure 28 will be fixed to the main body member 15 or the framed member 22 of the locking device 18. Also the hydraulic cylinder barrel 29 will be fixed to the connection structure 28. The position and dimensions of the release tool 27 will be such that the piston rod 30 can push the latching body 19 into open position. In Fig. 13a the release tool is attached to the locking device 18, preferably with the help of an ROV. The piston rod 30 is in its innermost position, i.e. not engaged with the latching body 19. In Fig.13b the piston pushes on the latching body 19, and the latching body 19 will push the chain link 14 further into the main body member 15 (upwards in the figure). In Fig. 13c the piston 30 is at its outermost position and the latching body 19 is fully open. The chain link 14 is no longer hanging on the locking device but has fallen onto the piston rod and thus resting on the piston rod. In Fig. 13d the piston rod is moved back and such that the chain link 14 gets fully free, implying that the latching body 19 is no longer connected to the chain link 14. Fig.14 shows an alternative method for disconnection. In this embodiment the entire arrangement is lifted back onto the hang-off structure 13. A counterweight assembly 31 comprising a lever arm 32 and a weight element 33 is attached to the joining structure 23, preferably with the help of an ROV. This counterweight assembly 31 provides a moment relative the hinge 24 which is larger than the moment provided by the weight of the latching body 19. When the locking device 18 is fully resting on the hang-off structure 13 the chain link 14 will not rest on the latching body 19. In this scenario the counterweight assembly 31 will open the latching body 19 and the invention can be lifted free from the chain link 14. Fig. 14a shows the scenario where the counterweight assembly 31 is attached to the joining structure 23 but the chain link 14 is still fully engaged with the latching body 19. In Fig. 14b the invention is lowered fully onto the hang-off structure 13 such that the chain link 14 is pushed into the main body member 15. The counterweight assembly 31 then starts to open the locking device 18. In Fig. 14c the latching body 19 is fully open and the lift off of the invention has started. In Fig.14d the invention is lifted fully clear of the chain link 14. For the arrangements in Fig.13 and Fig.14, and other workable arrangements, it is likely that the invention must be cleaned before the tools are attached. In the embodiment of the invention described above the mooring line type connected to the passive end 34 is exemplified as a chain. Other mooring line types, such as steel wire rope segments and synthetic rope segments, are equally applicable. Fig. 15a shows a typical main body member 15 where the passive end 34 interfaces with the thimble / spool 36 for a synthetic rope. Fig. 15b shows a main body member 15 where the passive end would fit an open socket of a steel wire rope or a shackle. The main body 15 can also be directly connected to any other types of structures at the passive end 34, such as buoyancy elements, clump weights, steel rods, etc.. In the embodiment of the invention described above the interfacing structure 14 connected to the receptacle end 35 is exemplified as a chain link. As long as this interfacing structure has a shape comprising an opening in the center, in which the locking device can enter into when closing, it does not need to be a chain link as shown in Fig. 16a. It can also be structures, but not limited to, similar to those shown in Fig. 16b and 16c. In addition to the opening in the center, common features of these interfacing structures 14 is that they have a first end 49 at which the latching body 19 locks the structure to the locking device 18, and a second end 50 which may be connected to an anchor chain 10, another type of mooring line component, anchor structure, etc.. Another common feature is the outer extremity 47 of the interfacing structure 14, which pushes the latching body 19 into open position when the locking device 18 is pushed onto, dropped onto or lowered onto the interfacing structure 14. Then, when the first end 49 has passed the open latching body 19 the locking device will rotate into locked position and lock the interfacing structure via contact with the inner extremity 48 of the interfacing structure 14. The first aspect of this disclosure shows a self-latching locking device 18 for mating with a connecting structure, the locking device comprises: - a body member 15 with a receptacle end 35 comprising at least two parallel end members 35,35’ each comprising a locking aperture 42,43 - a framed member 22 at least partly surrounding, and attached to, the body member 15, wherein the framed member 22 comprises an aligning receptacle 40 adapted to receive and align a portion of connecting structure 10,14 to be locked, - a locking latch 52 pivotably attached to the framed member 22 or the body member 15 and adapted to intervene in the first and second locking apertures 42,43. As seen in Figs.12a-12j the locking latch 52 is rotatable around axis 51 through hinge means 24 on the framed member 22 or the body member 15, wherein the axis 51 is lateral offset a distance d1 from a longitudinal centerline axis 44 going through two parallel end members 35’,35’’. The body member 15 may comprise an H-shaped member and wherein the two parallel end members 35’, 35’’ of the receptacle end 35 is the downwards protruding portion of said H-shaped member, wherein each of the two parallel end members 35’,35’’ comprises the first and second locking apertures 42,43. Each of the first and second locking apertures 42,43 may comprise corresponding contact surfaces 54,55 aligned at an angle Į, ǃ (see Fig.9c). The locking latch 52 of the locking device 18 may comprises two contact surfaces 41,41’ adapted to being in contact with the respective first and second corresponding contact surfaces 54,55 in the perimeter of the first and second locking apertures 42,43. As seen further in Fig.8 the locking latch 52 is illustrated with a joining structure 23 between the latching body 19 and the hinge means 24 distancing the latching body 19 from the hinge means 24 at least a radial distance D2 (see Fig. 9c) from the axis 51, wherein the latching body 19 and the joining means 23 together has a center of mass providing a rotational moment around the hinge means 24. The tension member 37 is connected between, and / or to, the joining structure 23 and the attachment structure 22 or main body 15, such that it may pretension the locking latch 52 towards a locking state, however not to the degree that the locking latch 52 latches and locks without the introduction and mating of a portion of connecting structure 10,14. On the top of the connection device 18, the body member 15 comprises a passive end 34 adapted to receive fastening means 25 for attachment of a mooring element 11, such as a mooring chain or the like, to the connection device 18. Thereby connecting the connecting structure 10,14 with the mooring element 11 when the connection device 18 mates said two elements. The locking latch 52 may further comprises a counterweight assembly 31 comprising a lever arm 32 protruding from the locking latch 52, or parts thereof, and a weight element 33 at an distal end of the lever arm 32, as seen in Figs.14a-14d. Said counterweight assembly 31 may be used to un-lock the locking latch, and may be accessible and operable by an ROV 26 or a line (not shown). The second aspect of this disclosure shows a locking system for locking at least a mooring element 11, such as a line to a connecting structure 10,14, the system comprising the locking device according to the first aspect, a mooring element 11 attached to the passive end 34 of the body member 15, and a connecting structure 10,14 adapted to be locked to the locking device according to the first aspect. In both the first and second aspect, the body member 15 comprises at least a first passive end 34 comprising fastening means 25 to fasten and secure a mooring element 11, wherein the mooring element 11 may EH^DQ\^RQH^RI^^D^ chain, steel wire rope, a socket for a steel wire rope, a synthetic rope, a thimble for a synthetic rope, a shackle, a mooring line buoyancy element, a mooring line clump weight, a rod structure of any kind, a chain, a chain element, a mooring line, a mooring chain. In both the first and second aspect, the connecting structure 10, 14 can be a chain link, the end of a chain, or a structure with a comparable interface as a chain link, such as an arched or bent rod or wire. The system may further comprise a release tool 27 adapted to open the locking latch 52, or move the locking latch 52 from a closed position to an open position. For instance, if the mooring element 11 and connecting structure 10, 14 are mated with the device, the release tool 27 can be used to free the locking latch 52 from the closed position. The release tool 27 may comprise a connection structure 28, adapted to be attached to the body member 15 or attachment structure 22, and a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel 29 and a piston rod 30 the piston rod 30 are arranged to forcibly move the locking body 19, and or locking latch 52 from a closed position and into an open position. The release tool might also comprise a screw and a gear arrangement attachable to the locking device 18 and being arranged to forcibly move the locking body 19, and or locking latch 52 from a closed position and into an open position. The release tool 27 and / or the counterweight assembly 31 can be controlled, powered and / or operated by a separate element, such as a controller or an ROV 26. In a further aspect, it is provided a method for connection a mooring element 11 to a connecting structure 10,14, wherein the method comprises the steps of: - providing a mooring element 11 with the locking device 18 according to the first aspect, or the system according to the second aspect, - lower said locking device 18 onto a portion of the connecting structure 10,14, - align, if the connecting structure 10,14 is not aligned with the receptacle end 35, the connecting structure 10,14 and receptacle end 35 by the aligning receptacle 40, - mate the connecting structure 10,14 and the receptacle end 35 until the locking latch 52 intervenes between the connecting structure 10,14 and the receptacle end 35 and locks into contact with the first and second inclined contact surface 41,41’. In a further aspect, it is provided method for disconnecting a mooring element 11 and connecting structure 10,14 connected by a locking device 18 according to the first aspect, or the system according to the second aspect, the method comprising the steps of: - releasing tension from the connecting structure 10,14 and / or the locking device, - move the locking latch 52 from its locked position to its unlocked position using an unlocking means 27,28,29,30,31,32,33, - removing the connecting structure 10,14 from the receptacle end 35. In the method for disconnecting according an aspect, the unlocking means 27,28,29,30,31,32,33 is a counterweight assembly 31 comprising a lever arm 32 protruding from the locking latch 52, or parts thereof, and a weight element 33 at an distal end of the lever arm 32 and / or an release tool 27 comprising connection structure 28, adapted to be attached to the body member 15 or attachment structure 22, and a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel 29 and a piston rod 30, the piston rod 30 is arranged to forcibly move the locking device 19 from a closed position and into an open position. Although specific embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents. For instance, the hang-off structure 13 may be a separate structure, which is not fixed to the anchor 5, but located away from the anchor. Further, the framed member 22 may be an integral part of the main body 15, or a separate but connectable and attachable element, as shown in the embodiment exemplified above. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims. Reference numerals 1 Floating unit 2 Sea surface 3 Seabed (also denoted mudline or sea floor) 4 Mooring line or part of mooring line 5 Anchor in general 6 Power cable 7 Connection element 8 Pile anchor 9 Suction anchor 10 Second mooring element, anchor chain (also denoted lower chain) 11 Mooring element, Chain segment connected to anchor chain via connector or connection element (also denoted upper chain) 12 Chain connector (also denoted connector) 13 Hang-off structure for anchor chain at anchor top 14 Chain link at upper end of anchor chain, which mates with chain connector (also denoted interfacing structure) 15 Main body of connector 16 Guide structure (part of hang-off structure) 17 Permanent or detachable structure for guiding and installation of ROV operated pin, where pin locks connector to chain link at upper end of anchor chain 18 Self-latching locking device 19 Latching body 20 Locking segment (in open position) 21 Locking segment (in closed position) 22 Attachment structure 23 Joining structure between locking segment and attachment structure via hinge. 24 Hinge 25 Pin for locking upper chain to main body of invention 26 Remotely Operated Vehicle (ROV) 27 Release tool 28 Connection structure of release tool 29 Hydraulic cylinder barrel of release tool 30 Piston rod of release tool 31 Counterweight assembly 32 Lever arm 33 Weight element 34 Passive end 35 Receptacle end 35’, 35’’ Parallel end members of receptacle end 36 Thimble / spool of synthetic rope segment 37 Tension member, spring 38 Tension member connection on attachment structure or main body 39 Tension member connection on joining structure 40 Guide structure of the attachment structure for rotating and aligning the device relative the mating structure (herein the uppermost chain link of the anchor chain) 41, 41’ First and second inclined contact surface 42 Opening for locking device in main body at opposite side of hinge 43 Opening for locking device in main body at same side as hinge 44 Longitudinal axis of main body (centerline) 45 Longitudinal axis of locking device 46 Lump on locking device 47 Outer extremity of interfacing structure 48 Inner extremity of interfacing structure 49 First end of interfacing structure 50 Second end of interfacing structure 51 Axis through hinged point 52 Locking latch 53 Link contact surface 54 First corresponding contact surface 55 Second corresponding contact surface 56 Feet of joining structure

Claims

Claims 1. A self-latching locking device (18) for mating with a connecting structure (10, 14), the locking device comprises: - a body member (15) with a receptacle end (35) comprising at least two parallel end members (35’, 35’’) each comprising a locking aperture (42, 43) - a framed member (22) at least partly surrounding, and attached to, the body member (15), wherein the framed member (22) comprises an aligning receptacle (40) adapted to receive and align a portion of the connecting structure (10, 14) to be locked, - a locking latch (52) pivotably attached to the framed member (22) or the body member (15) and adapted to intervene in the first and second locking apertures (42, 43).

2. The locking device according to claim 1, wherein the locking latch (52) is rotatable around axis (51) through hinge means (24) on the framed member (22) or the body member (15), wherein the axis (51) is lateral offset a distance (d1) from a longitudinal centerline axis (44) going through two parallel end members (35’, 35’’).

3. The locking device according to claim 1 or 2, wherein the locking latch comprising two contact surfaces (41, 41’) adapted to being in contact with respective first and second corresponding contact surfaces (54, 55) in the perimeter of the first and second locking apertures (42, 43).

4. The locking device according to any one of the previous claims, wherein the locking latch (52) comprises a latching body (19) comprising a: - a first contact surface (41) adapted to be in locking contact with the first corresponding contact surface (54) of the first locking aperture (42), wherein the a first contact surface and first corresponding contact surface are aligned and at an angle ɲ to an axis (45), and; - a second contact surface (41’) adapted to be in locking contact with the second corresponding contact surface (55) of the second locking aperture (43), wherein the a second contact surface and second corresponding contact surface are aligned and at an angle ɴ to an axis (51), and; - a link contact surface (53) on and opposite side of latching body (19) from the first and second contact surface, wherein the link contact surface (53) is adapted to contact and receive the load of the connecting structure (10, 14) or a chain to be locked, wherein the opposite angled contact surfaces are adapted to compress the two parallel ends (35, 35’) of the body member (15) when the load from a connecting structure (10, 14) acts on the locking latch (52).

5. The locking device according to any one of the previous claims, wherein the locking latch (52) further comprises a joining structure (23) between the latching body (19) and the hinge means (24) distancing the latching body (19) from the hinge means (24) at least a radial distance (d2) from the axis (51).

6. The locking device according to any one of the previous claims, wherein the latching body (19) and the joining means (23) together has a center of mass providing a rotational moment around the hinge means (24).

7. The locking device according to any one of the previous claims, wherein a tension member (37) is connected between the joining structure (23) and the attachment structure (22) or main body (15) at the other end.

8. The locking device according to any one of the previous claims, wherein the body member (15) comprises at least a passive end (34) adapted to receive fastening means (25) for a mooring element (11).

9. The locking device according to any one of the previous claims, wherein the locking latch (52) further comprises a counterweight assembly (31) comprising a lever arm (32) protruding from the locking latch (52), or parts thereof, and a weight element (33) at an distal end of the lever arm (32).

10. A locking system for locking at least a line to a connecting structure, the system comprising the locking device according to any one of the claims 1-9, a mooring element (11) attached to the first passive end (34) of the body member (15), and a connecting structure (10, 14) adapted to be locked to the self-latching locking device.

11. The locking system according to claim 10, wherein the body member (15) comprises at least a first passive end (34) to receive fastening means (25) for a separate mooring element (11), wherein the mooring element (11) can be any one of; a chain, steel wire rope, a socket for a steel wire rope, a synthetic rope, a thimble for a synthetic rope, a shackle, a mooring line buoyancy element, a mooring line clump weight, a rod structure of any kind, a chain, a chain element.

12. The locking system according to claim 10 or 11, wherein the connecting structure (10, 14) can be a chain link (14), the end of a chain (10), or a structure with a comparable interface as a chain link, such as an arched or bent rod or wire.

13. The locking system according to any one of the claims 10-12, wherein the system further comprises a release tool (27). 14- The locking system according to claim 13, wherein the release tool (27) comprises - a connection structure (28), adapted to be attached to the body member (15) or attachment structure (22), and; - a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel (29) and a piston rod (30), and / or a screw and a gear arrangement, the piston rod (30) and / or a screw and a gear arrangement is arranged to forcibly move the locking device (19) from a closed position and into an open position.

15. A method for connecting a mooring element (11) to a connecting structure (10, 14), wherein the method comprising the steps of: - providing a mooring element (11) with the locking device (18) according to any one of the claims 1- 9, - lower said locking device (18) onto a portion of the connecting structure (10, 14), - align, if the connecting structure (10, 14) is not aligned with the receptacle end (35), the connecting structure (10, 14) and receptacle end (35) by the aligning receptacle (40), - mate the connectingstructure (10, 14) and the receptacle end (35) until the locking latch (52) intervenes between the connecting structure (10, 14) and the receptacle end (35) and locks into contact with the first and second inclined contact surface (41, 41’).

16. A method for disconnecting a mooring element (11) and connecting structure (10, 14) connected by a locking device (18) according to any one of the claims 1-9, the method comprising the steps of: - releasing tension from the connecting structure (10, 14) and / or the locking device, - providing unlocking means (27, 28, 29, 30, 31, 32, 33), - move the locking latch (52) from its locked position to its unlocked position using the unlocking mean (27, 28, 29, 30, 31, 32, 33), - removing the connecting structure (10, 14) from the receptacle end (35) 17. The method according to claim 16, wherein the unlocking means (27, 28, 29, 3031, 32, 33) is a counterweight assembly (31) comprising a lever arm (32) protruding from the locking latch (52), or parts thereof, and a weight element (33) at an distal end of the lever arm (32) and / or an release tool (27) comprising connection structure (28), adapted to be attached to the body member (15) or attachment structure (22), and a hydraulic cylinder, where the hydraulic cylinder comprises a hydraulic cylinder barrel (29) and a piston rod (30), the piston rod (30) is arranged to forcibly move the locking device (19) from a closed position and into an open position.

18. The method according to claim 165 or 17, wherein the unlocking mean (27, 28, 29, 3031, 32, 33) is operated and / or actuated by an ROV (26).

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