Offshore structures, especially floating offshore structures

Abstract

1. An offshore structure (100, 200, 300, 400, 500, 600, 700, 800), in particular a floating offshore structure (200, 300, 400, 500, 600, 700, 800), comprising at least one subsea cable connector (102, 203, 302, 502, 602, 702, 802) configured to connect a subsea power cable (108, 208, 308, 508, 608, 708, 808) to an electrical device (104, 204) of the offshore structure (100, 200, 300, 400, 500, 600, 700, 800), The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) further comprises at least one messenger line (114, 214, 314, 514, 614, 714), and a first end (101, 201, 301, 501, 601, 701) of the messenger line (114, 214, 314, 514, 614, 714) is connected to a submarine power cable (108, 208, 308, 508, 608, 708, 808) and a further end (103, 203, 303, 503, 603, 703) of the messenger line (114, 214, 314, 514, 614, 714) is fixed to the offshore structure (100, 200, 300, 400, 500, 600, 700, 800).

Description

[Technical Field]

[0001] The present application relates to an offshore structure, particularly a floating offshore structure, comprising at least one subsea cable connector configured to connect a subsea power cable to an electrical device on the offshore structure. Further, the present application relates to a messenger line system, a subsea power cable system, and a power generation system. [Background technology]

[0002] Currently, power generation systems are increasingly used to provide electrical energy, the generation of which is based on so-called renewable energy sources. A power generation system comprises at least one power generation device, preferably several power generation devices.

[0003] For example, wind energy systems or wind power plants having at least one wind turbine as an energy generating device are used as electrical energy generating systems. Specifically, the wind turbine is configured to convert the kinetic energy of wind into electrical energy. In addition to wind power plants, photovoltaic systems or photovoltaic power plants are also increasingly being built as electrical energy generating systems, and typically include multiple photovoltaic modules for electrical energy generation.

[0004] Such power generation systems are increasingly being located offshore as well as on land. There are many reasons for choosing offshore locations, for example, the availability of space on land may be limited. Furthermore, it has been shown that wind power plants, for example, can increase the amount of energy produced. Offshore locations are usually characterized by relatively uninterrupted wind conditions and high average wind speeds, which is why offshore wind power plants are increasingly being built. For example, offshore photovoltaic power plants may be located due to space constraints.

[0005] Typically, an offshore power generation system has multiple (stationary) offshore structures, such as multiple offshore wind turbines and at least one offshore electrical substation (also called converter station), which can electrically connect the offshore wind farm to, for example, an onshore substation or another offshore substation.

[0006] Furthermore, onshore substations can be connected to the public power grid.To transmit power between two offshore structures or between an offshore structure and an onshore structure, power cables are laid between said structures in the form of subsea power cables.

[0007] While it has been common practice to anchor not only offshore wind turbines and offshore substations, but also other offshore structures such as photovoltaic platforms, platforms for gas or oil exploration, and platforms for hydrogen production, to the waterbed, specifically on or in the seabed, by foundation structures (e.g., monopile foundations, tripod foundations, tripile foundations, jacket foundations, etc.), there is increasing consideration of installing floating or buoyant offshore structures, for example, floating power generation devices such as floating offshore wind turbines or floating photovoltaic platforms.

[0008] One of the reasons for using floating offshore structures is that such structures can be installed in areas with great water depths, for example, greater than 150 meters.

[0009] The buoyant or floating offshore structure may comprise at least one floating foundation having at least one float. The offshore structure, in particular an offshore device supported by the foundation, may have at least one subsea power cable connector. In a variant, a subsea power cable connection may also be arranged in the foundation. The subsea power cable connector is configured to connect a subsea power cable, in particular with an electrical device of the offshore structure.

[0010] For example, a transformer device having at least one transformer, a wind power generation device, a photovoltaic device, a hydrogen production device, etc. can be installed as an offshore device on the foundation of an offshore structure.

[0011] In particular, (mechanical) disconnection of a subsea power cable from a subsea cable connection may occur in the case of floating offshore structures, but also in the case of non-floating offshore structures (and those installed on the seabed via conventional foundations). Mechanical disconnection of a subsea power cable may have various causes. For example, mechanical disconnection may be intentional, such as in the case of maintenance or repair. However, mechanical disconnection of a subsea power cable from an offshore structure may also include (unintentional) breakage of the subsea power cable.

[0012] As will be explained herein below, the risk of such (unintentional) damage is particularly high in the case of floating offshore structures. For (permanent) stationary operation of a floating offshore structure at a particular installation location, the floating offshore structure is attached to the subsea bottom (typically the seabed) by at least one mooring mechanism. The at least one mooring mechanism is configured to stabilize the floating offshore structure relative to the seabed in the offshore structure's moored or installed state.

[0013] To that end, the mooring arrangement may comprise at least one anchor connection extending between the anchor at least partially buried in the seabed and the floating offshore structure. The offshore structure may comprise at least one anchor connector. The anchor connector may be configured to connect at least one anchor connection for anchoring the floating offshore structure to the seabed. In a preferred variant, two or more anchor connections may be connected or attached to each anchor connector of the offshore structure.

[0014] A problem with the described floating offshore structures is that the anchor connections may break or become detached during operation of the floating offshore structure, for example due to high mechanical loads acting on the anchor connections during operation, accidents with ships, etc.

[0015] As a result of the failure of the anchor connection, the connected subsea power cable may also break or break. When a subsea power cable breaks, it sinks to the seabed, which is particularly problematic when the water depth is great. Locating a subsea cable at great depth is complex and time-consuming. Once the subsea cable has been located, a complex salvage operation is then required. It should be noted that subsea power cables may also become detached from the non-floating offshore structure, for example due to high mechanical loads.

[0016] It is therefore an object of the present application to provide the possibility of reducing the effort required to salvage a subsea power cable that has been mechanically disconnected from an offshore structure. Summary of the Invention [Means for solving the problem]

[0017] According to a first aspect of the present application, the object is achieved by an offshore structure, in particular a floating offshore structure, as set forth in claim 1. The offshore structure comprises at least one subsea cable connector configured to connect a subsea power cable to at least one electrical device on the offshore structure. The offshore structure further comprises at least one messenger line, a first end of which is fixed to the subsea power cable and a further end of which is fixed to the offshore structure.

[0018] Unlike the prior art, according to the present application, the possibility of reducing the effort of salvaging a subsea power cable that has been mechanically disconnected from an offshore structure, specifically a broken subsea power cable, is provided by providing a messenger line between the offshore structure and the subsea power cable. The messenger line is specifically configured to hold the broken subsea power cable. Since the messenger line is connected to the subsea power cable after the break, there is no need for complex location identification of the broken subsea power cable. Also, the salvage operation of the disconnected subsea power cable, which is still linked to the offshore structure, is facilitated.

[0019] The offshore structure is in particular a stationary offshore structure during operation, i.e. after installation of the offshore structure. In particular, vehicles such as ships, vessels, etc. are not offshore structures according to the present application. Preferably, the offshore structure is a floating (stationary) offshore structure that floats at a specific installation location.

[0020] An offshore structure according to the present application includes at least one subsea (power) cable connector. For example, two subsea power connectors may be provided. The subsea power connectors are configured specifically for connecting subsea power cables during operation of the offshore structure. For example, two subsea power cables may be connected to the offshore structure, each with a subsea power connector.

[0021] In particular, the subsea power cable is configured to transmit electrical energy or power. The subsea power cable is preferably a medium voltage subsea power cable (in particular between 3 kV and 30 kV) or a high voltage subsea power cable (60 kV to 110 kV). The power capacity of the subsea power cable according to the present application is preferably between 3 MW and 2.5 GW. Furthermore, the subsea power cable may be equipped to transmit data.

[0022] In particular, a subsea power cable according to the present application may extend from a subsea cable connector to the subsea floor and then through the subsea floor for a particular depth range. If the further structure connected to the subsea power cable is also an offshore structure, the subsea power cable may extend from the subsea floor to a further subsea cable connector on the further (floating) offshore structure. If the further structure connected to the subsea power cable is an onshore structure, the subsea power cable may extend substantially through the bottom to a further subsea cable connector on the onshore structure.

[0023] The at least one subsea cable connector is configured to connect the subsea power cable to one or more electrical devices of the offshore structure. The offshore structure may preferably comprise a foundation configured to support at least one offshore device comprising the at least one electrical device.

[0024] The floating offshore structure may comprise an offshore device disposed on the foundation. The offshore device may comprise at least one subsea cable connector. Preferably, the offshore device may comprise at least one electrical device in the form of a power generation device or an electrical consumer. Non-exhaustive exemplary offshore devices include a substation device comprising at least one electrical transformer, a wind power generation device (e.g., comprising a tower, a nacelle, a rotor, a generator, etc.), a photovoltaic device (preferably comprising a plurality of photovoltaic modules), and a hydrogen production device, in particular a water electrolysis device.

[0025] According to a preferred embodiment of the (floating) offshore structure according to the present application, the foundation may be a floating foundation comprising at least one floating body. The floating or buoyant body is independently buoyant, in particular by the buoyancy of the displacement according to Archimedes' principle. The floating body may, for example, be hollow and filled with a gas, for example air, or with a lightweight solid. In particular, the buoyant foundation may substantially form the floating body.

[0026] Preferably, the floating foundation may be a so-called barge foundation, semi-submersible foundation, spar foundation, and / or tension-tethered platform (TLP) foundation, although it is understood that other types of floating foundations may be provided in other variations of the present application.

[0027] In accordance with the present application, it has been recognized that the effort required to salvage a damaged subsea power cable can be reduced if at least one messenger line or messenger wire is connected between the offshore structure and the subsea power cable connected to a subsea cable connector on the offshore structure. The connection of the messenger line to the offshore structure can be a direct connection or an indirect connection (e.g., by a buoy associated with the offshore structure).

[0028] According to the present application, a first end of a messenger line is (rigidly) fixed to the subsea power cable, a further end of the messenger line is (rigidly) fixed to the offshore structure, and the messenger line is connected to the subsea power cable and to the offshore structure in particular such that in the event of a break in the subsea power cable there is still a link between the subsea power cable and the offshore structure via the messenger line.

[0029] According to a further embodiment of the offshore structure according to the present application, the first end of the messenger line can be fixed to the subsea power cable in an end region of the first end of the subsea power cable that is connected to the subsea cable connector. The length of the end region (starting from the subsea cable connector of the offshore structure) is in particular between 0 and 40 m, particularly preferably between 0 and 20 m. It has been recognized that if a subsea power cable breaks, it will usually break at a point on the cable within a distance of 0 to 20 m, in particular 0 to 1 m, from the subsea cable connector.

[0030] Alternatively or additionally, the first end of the messenger line can be secured to the subsea power cable at a cable connector (particularly a plug of the subsea power cable) of the subsea power cable (connected to the subsea cable connector of the offshore structure). It has been particularly recognized that if a subsea power cable breaks, it will usually break at a point on the cable between the respective cable connectors. Furthermore, the messenger line can be simply secured to the cable connector of the subsea power cable.

[0031] According to a preferred embodiment of the offshore structure according to the present application, the subsea power cable may comprise a weak link, particularly in an end region of a first end of the subsea power cable. The weak link is particularly a predetermined severance point. The weak link may be a region of the subsea power cable that is configured (mechanically and / or structurally) so that the tensile strength at said weak link is lower than in the remaining cable region of the subsea power cable. By providing a specially designed weak link, it may be particularly ensured that, in the event of a break in the subsea power cable, the subsea power cable will (at least likely) break (only) at the weak link.

[0032] Preferably, the first end of the messenger line may be secured to the subsea power cable downstream of the weak link, starting from the subsea cable connector on the offshore structure, to ensure that in the event of a break in the subsea power cable (at the weak link), a link still exists between the offshore structure and the subsea power cable via the connected messenger line.

[0033] According to a further embodiment, the offshore structure may comprise at least one switching device configured to mechanically disconnect the subsea power cable upon receiving a disconnect command. The switching device may be connected, for example, at the weak link. In order to prevent uncontrolled cable breakage, a disconnect command may be transmitted to the switching device, in particular upon detection of an (imminent) cable break (e.g., by detecting an indication of anchor connection breakage). The switching device then immediately performs a controlled disconnection at the cable location designated therefor (e.g., at the weak link). Preferably, a first end of the messenger line may be anchored to the subsea power cable, starting from a subsea cable connector at the offshore structure, downstream of the cable location designated therefor (e.g., the weak link). In one embodiment, the weak link may be a hang-off at the offshore structure.

[0034] According to a further embodiment of the offshore structure according to the present application, the first end of the messenger line can be secured to the subsea power cable via at least one anchoring module, the at least one anchoring module comprising: - at least one eyelet attached to the cable connector; - at least one eyelet attached to the subsea power cable, in particular to the cable sheath of the subsea power cable; - at least one additional (cable) sheath of the submarine power cable, into which the first end of the messenger line is integrated; - at least one Chinese finger incorporating a first end of a messenger line; The compound may be selected from the group comprising:

[0035] It is possible to provide a secure fixation that is at the same time easy to establish.

[0036] Similar fastening modules (eg, eyelets, Chinese fingers, welded connections, etc.) can be used to fasten the further end of the messenger line to the offshore structure.

[0037] Furthermore, according to a further embodiment of the offshore structure according to the present application, a further end of the messenger line can be secured to the offshore structure at at least one structural element (at least associated with the offshore structure), the at least one structural element comprising: - Hang-off of offshore structures and - Airtight decks of offshore structures; - a hollow structure (preferably a J-tube) configured to guide the subsea power cable from the subsea cable connector along the offshore structure; - (floating) foundations for offshore structures; - At least one buoy associated with the offshore structure; The compound may be selected from the group comprising:

[0038] The offshore structure hang-off (system) can be configured to stabilize the subsea power cable on top of the offshore structure foundation / cable deck. The offshore structure airtight deck can be incorporated into an offshore device, particularly located above the offshore structure service platform.

[0039] The offshore structure may be provided with a hollow (guiding) structure for guiding the subsea power cable connected to the subsea cable connector in a defined manner towards the seabed. The subsea power cable may extend through the hollow structure from the subsea cable connector to an outlet of the hollow structure. The further end of the messenger line may be fixed inside the hollow structure or outside the hollow structure.

[0040] Alternatively or additionally, a further end of the messenger line may be fixed to at least one foundation (in particular a foundation wall) of the offshore structure.

[0041] At least one buoy can be associated with the offshore structure. A buoy can be associated with an offshore structure if the buoy is permanently located in a certain vicinity (e.g., within a radius of X meters) of the (installed) offshore structure at the installation site. The advantage of a buoy (not permanently connected to the floating offshore structure) is that even if the floating offshore structure drifts (significantly) away from its original installation site or position, no breakage of the messenger line occurs because the subsea power cable is connected to the buoy via the messenger line. Even if the floating offshore structure drifts, the salvage process can be facilitated.

[0042] In order to maintain the messenger line connection between the offshore structure and the subsea power cable in the event of a break in the subsea power cable, in accordance with an embodiment of the offshore structure according to the present application, the messenger line may be configured to tolerate a maximum force of at least 1000 kN, preferably at least 1500 kN, e.g., a length of 1500 m, a cross-sectional area of ​​2000 mm 2 Based on a 275kV subsea cable, the messenger line can be configured to tolerate a maximum force of at least 1500kN.

[0043] Specifically, to tolerate such maximum forces, according to an embodiment of the offshore structure of the present application, the messenger line: - Metals, especially steel, - Plastic and - Fiber-reinforced plastics, in particular carbon fiber-reinforced polymers, glass fiber-reinforced polymers and / or aramid fiber-reinforced polymers; The material may be selected from the group including:

[0044] Particularly preferred are steel ropes and / or fiber reinforced plastic ropes. Preferably, two or more steel ropes and / or fiber reinforced plastic ropes may be twisted together to form the messenger line.

[0045] It has been recognized that although subsea power cables may have certain weak links, they may occasionally break at other points on the cable. A further problem that sometimes arises is that messenger lines also break. To enable the location of a broken subsea power cable in these cases, in accordance with embodiments of the offshore structure of the present application, the subsea power cable may be equipped with at least one tracking transmitter. In particular, the offshore structure may comprise a subsea power cable.

[0046] The at least one tracking transmitter may be a sonar-based tracking transmitter and / or an electromagnetic-based tracking transmitter. Preferably, the tracking transmitter may be an emergency locator beacon, such as an Emergency Position Indicating Radio Beacon (EPIRB). The tracking transmitter may be capable of automatically activating upon damage. The tracking transmitter may be battery-powered. Upon activation, the tracking transmitter may be configured to broadcast its location (e.g., to an accuracy of 100 m).

[0047] Alternatively or additionally, the offshore structure may include two messenger lines each connected to the same subsea power cable. A respective first end of each messenger line may be fixed to the subsea power cable (preferably at different distances to the subsea cable connector), and a respective further end of each messenger line may be fixed to the offshore structure. In other words, two or more messenger lines may be provided for each subsea power cable.

[0048] Alternatively or additionally, the subsea power cable may be additionally equipped with at least one inflatable float. The at least one inflatable float may be arranged in at least one cable end region of the subsea power cable. The inflatable float may include at least one inflatable bladder configured to inflate upon receiving a trigger command. The inflatable float may include an inflatable bladder configured specifically to inflate when the subsea power cable is broken. The inflated inflatable float carries the broken subsea power cable in an inflated state above the sea surface, thereby facilitating the salvage operation of the severed subsea power cable.

[0049] Preferably, the inflatable float can be secured to the subsea power cable downstream of the weak link (starting from or viewed from the cable connector of the subsea power cable or the subsea cable connector of the offshore structure in a connected state). The inflatable float can be secured to the subsea power cable via at least one anchoring module. The at least one anchoring module comprises: - at least one eyelet attached to the cable connector; - at least one eyelet attached to the subsea power cable, in particular to the cable sheath of the subsea power cable; - at least one additional sheath in which the inflatable floatation body is at least partially integrated; - at least one Chinese finger at least partially incorporating an inflatable float; - Welded connections, - Sticky connection and The compound may be selected from the group comprising:

[0050] According to a preferred embodiment of the offshore structure of the present application, the inflatable float may include at least one gas generator and at least one inflatable bladder. The at least one inflatable bladder or hull is, in particular, an airbag. The gas generator may be configured to fill the inflatable bladder with gas. The gas generator may provide gas to fill the inflatable bladder, in particular the airbag. In particular, upon (immediately after) activation of the inflatable float, the gas generator may inject gas into the inflatable bladder. After the inflatable bladder is essentially fully inflated (i.e., the inflatable bladder is in an inflated state), the inflatable float may be configured to seal the inflated bladder so that the gas remains in the inflated bladder.

[0051] Preferably, the at least one gas generator comprises: - a compressed air reservoir; - a pyrotechnic gas generator; - a cryogenic gas generator; - Hybrid gas generator and is selected from the group comprising:

[0052] The compressed air reservoir may be provided with a valve that can be opened to fill the inflatable float with air stored in the compressed air reservoir. Such an embodiment may be advantageous, as a compressed air reservoir with such an actuatable valve can simplify the design and practicality of the inflatable float. In particular, a particularly fast inflation process is usually not required.

[0053] The pyrotechnic gas generator may include an ignition unit and a solid accelerant. The ignition unit may be activated by a current pulse. The current pulse may ignite the solid accelerant. The solid accelerant may be in the form of a tablet. The resulting hot gas (e.g., about 1350°C) may flow from the gas generator into an inflatable bladder. Expansion may reduce the temperature of the gas flowing into the inflatable bladder (e.g., to about 150°C).

[0054] The cryogenic gas generator may include a gas reservoir and an activator. For example, a helium-argon mixture may be stored under high pressure. When the inflatable float is triggered, an explosive device may rupture the membrane, allowing cryogenic gas to flow into the inflatable bladder. A hybrid gas generator is specifically a combination of a pyrotechnic gas generator and a cryogenic gas generator. It is understood that other gas generators may be used.

[0055] According to a further embodiment of the offshore structure of the present application, the inflatable floating body may comprise at least one controller configured to receive a trigger command, and the controller may be configured to drive at least one gas generator (in particular at least one of the gas generators described above) to cause the gas generator to fill the inflatable bladder with gas.

[0056] Furthermore, according to an embodiment of the offshore structure of the present application, the inflatable float may include at least one trigger sensor configured to detect at least one trigger event. A trigger (break) event according to the present application is specifically an event indicating that the subsea power cable is (actually) broken. The trigger sensor may be configured to generate a trigger command upon detection of the trigger event. In other words, the trigger command may represent (or may be caused by) the detection of a broken subsea power cable. Generating the trigger command may include providing, specifically transmitting, the trigger command to a controller (to activate the inflatable float).

[0057] Alternatively, but preferably additionally, the inflatable float may comprise at least one receiving module configured to receive trigger event information. The trigger event information is information generated upon a trigger event (e.g., detected by a trigger sensor not provided on the inflatable float but provided, for example, by the offshore structure (particularly in the form of a detection mechanism described in more detail herein below)) indicating that the subsea power cable has been broken. The receiving module may be configured to generate a trigger command upon receipt of the trigger event information. Generating the trigger command may include providing, particularly transmitting, the trigger command to a controller (to activate the inflatable float).

[0058] According to a further embodiment of the offshore structure according to the present application, the at least one trigger sensor comprises: - an acceleration sensor; - a water contact sensor; - Ripcord sensor and a hollow structure sensor configured to detect that the inflatable float is no longer present within a hollow structure configured to guide the subsea power cable from the subsea cable connector of the offshore structure along the offshore structure; and The compound may be selected from the group comprising:

[0059] In general, the trigger sensor may be configured to (continuously) measure or monitor at least one parameter indicative of a subsea power cable break. The trigger sensor may be configured to evaluate whether at least one (continuously) measured or monitored parameter (value) satisfies a broken cable criterion (e.g., a predetermined parameter value range and / or at least one predetermined limit parameter value). If at least one (continuously) measured or monitored parameter (value) satisfies a broken cable criterion, the trigger sensor detects said trigger event. If at least one (continuously) measured or monitored parameter (value) does not satisfy a broken cable criterion, the trigger sensor does not detect said trigger event.

[0060] For example, an acceleration sensor may (continuously) measure at least one acceleration parameter of the inflatable float. If the at least one acceleration parameter exceeds a predetermined acceleration limit, the acceleration sensor may detect the trigger event. In particular, it may be expected that the acceleration sensor integrated into the inflatable float will reach an acceleration greater than the acceleration limit only if the subsea power cable breaks, e.g., falls into the sea.

[0061] Furthermore, the water contact sensor means can (continuously) measure or monitor at least one humidity parameter. The inflatable float can be positioned such that, in an unbroken state of the subsea power cable, the inflatable float, and therefore the water contact sensor, is not in contact with water at all times. If at least one humidity parameter exceeds a predetermined humidity limit, the water contact sensor can detect said trigger event. In particular, it can be assumed that the water contact sensor incorporated in the inflatable float may reach a humidity value greater than the humidity limit only if the subsea power cable breaks and falls into the sea.

[0062] The ripcord sensor can be connected to a ripcord, with a first end of the ripcord connected to the ripcord sensor and the other end connected to a structural element of, for example, an offshore structure. In particular, the ripcord is connected to the ripcord sensor so that if the power cable is broken, the ripcord is also disconnected, which can be monitored by the ripcord sensor. A criterion for a broken cable can be a faulty ripcord (or the like). If this is detected, the ripcord sensor can detect the trigger event.

[0063] The hollow structure sensor (e.g., optical sensor, contact sensor, etc.) can be configured to detect when the inflatable floater is no longer present in a hollow structure (e.g., a J-tube) configured to guide the subsea power cable along the offshore structure from a subsea cable connector on the offshore structure. The inflatable floater can be positioned such that, in an unbroken state of the subsea power cable, the inflatable floater, and therefore the water contact sensor, is within the hollow structure. In particular, the hollow structure sensor can evaluate at least one monitored parameter based on at least one broken cable criterion, whether or not the hollow structure sensor is outside the hollow structure.

[0064] In particular, it can be assumed that during normal operation the inflatable float, and therefore the hollow structure sensor, is within the hollow structure. If the hollow structure sensor detects that the hollow structure sensor, and therefore the inflatable float, is no longer within the hollow structure, it can be assumed that the subsea power cable has broken and fallen out of the hollow structure. A further advantage of the sensor is that it can ensure that the inflatable float is not activated until it is outside the hollow structure, preventing damage from the hollow structure to an already inflated float.

[0065] A time delay trigger (e.g., dependent on the length of the hollow body) may also be used to ensure that the inflatable float is only activated after it has left the hollow structure (and upon another sensor (e.g., acceleration sensor, ripcord sensor, water contact sensor, and / or detection mechanism as subsequently described)).

[0066] Furthermore, according to a further embodiment of the offshore structure of the present application, the inflatable bag has a height of 0.5 m in an inflated state (or activated state). 3 and 500m 3 Between, preferably 1.5m 3 and 150m 3 Such a volume can ensure sufficient buoyancy so that the cable end can float on the water surface. Alternatively, and preferably additionally, the inflatable bag can have a volume between 0.001 m and 0.001 m in its uninflated (or inactivated) state. 3 and 10m 3 Between, preferably 0.01m 3 and 4m 3 An inflatable float having such a small volume inflatable bag can be attached to a subsea power cable in a simple manner.

[0067] According to a preferred embodiment of the offshore structure of the present application, the length, specifically the design of the length, of at least one messenger line of the floating offshore structure is based on the water depth at the installation site of the floating offshore structure, the number of anchor connections of the floating offshore structure, and / or the shape of the path of the anchor connections from the floating offshore structure to the anchors fixed to the subsea floor. In the case of a floating offshore structure, it has been recognized that a break in the subsea power cable may occur if one of the anchor connections of the floating offshore structure breaks. In that case, the floating offshore structure typically drifts from its original installation point to a maximum drift position defined by the remaining anchor connections. To avoid breakage of the link between the offshore structure (e.g., foundation, airtight deck, hang-off (not associated buoy), etc.) and the subsea power cable due to the drift of the offshore structure, the length of the messenger line is determined based on at least one of the above parameters. For example, the offshore structure may include a messenger line compartment for receiving the messenger line when it is unused, i.e., when the subsea power cable is undamaged.

[0068] Preferably, the length of at least one messenger line of the floating offshore structure can be at least greater than the maximum distance that the floating offshore structure may move or drift when one of the plurality of anchor connections of the floating offshore structure is broken.

[0069] According to a further embodiment of the offshore structure according to the present application, the offshore structure may be a floating offshore structure. The floating offshore structure may comprise at least one anchor connector configured to connect at least one anchor connection for anchoring the floating offshore structure to a subsea floor. The floating offshore structure may comprise at least one detection mechanism configured to detect an indication of anchor connection failure. The floating offshore structure may comprise at least one switching device configured to at least electrically disconnect an electrical connection to a subsea power cable connected to the subsea cable connector upon or after detection of an indication of anchor connection failure.

[0070] By providing a detection mechanism for detecting indications of anchor connection failure, in particular a broken or disconnected anchor connection, and a switching device for interrupting the current through the connected subsea power cable upon such detection, safety during operation of the floating offshore structure can be improved; failure of live subsea power cables can be (safely) prevented; and unintentional short circuits can be avoided.

[0071] Preferably, if an optional switching device configured to mechanically disconnect the subsea power cable is provided, the detection mechanism may be configured to send the described disconnect command to the switching device in order to cause a (defined) disconnection of the subsea power cable from the offshore structure.

[0072] The floating offshore structure comprises at least one anchor connector. In particular, the foundation may comprise at least one anchor connector. The anchor connector is configured to (mechanically) connect at least one anchor connection. During operation, the offshore structure is attached or anchored to the subsea floor via the at least one anchor connection.

[0073] The anchor connection according to the present application is preferably an anchor rope and / or an anchor chain. The anchor rope may be made of metal, in particular steel, and / or plastic, in particular at least one fiber composite material. Preferably, two or more anchor ropes may be twisted together to form the anchor connection. A sheath may be provided to protect at least one anchor rope.

[0074] One end of the anchor connection portion may be connected to an anchor connector (in the installed state of the floating offshore structure), and the other end of the anchor connection portion may be connected to an anchor (e.g., a weight anchor, a torpedo anchor, etc.). The anchor may be at least partially buried in the subsea floor. Preferably, the floating offshore structure may have three (or more) anchor connections, which may be attached to, for example, a corresponding number of anchor connectors on the offshore structure.

[0075] The detection mechanism can be used for direct and / or indirect monitoring of at least one anchor connection, in particular all anchor connections, of the floating offshore structure, and in particular is configured to detect a broken or severed anchor connection.

[0076] Detecting an indication of anchor connection failure specifically refers to detecting a specific event or parameter that indicates a failed (actual or potential) anchor connection or an anchor connection that will fail with a high probability (e.g., >95%) (e.g., due to the current load on the anchor connection exceeding a predetermined maximum allowable load). Specifically, a potentially failed anchor connection exists when the detection mechanism detects a parameter or event that is indicative of a failed anchor connection, but which may also have other contributing factors, such as a flaw in the detection mechanism (e.g., measurement error or the like).

[0077] Upon or after detecting an indication of at least one anchor connection failure, an electrical disconnection of at least one of the connections of the offshore structure to the subsea power cables or electrical systems connected to the offshore structure is effected by the switching device. In particular, a disconnection of the electrical flow or an interruption of the energy flow through the at least one subsea power cable connected to the offshore structure occurs. In other words, the at least one subsea power cable is de-energized, preferably by the switching device.

[0078] Specifically, the switching device may include at least one load break switch. The at least one load break switch may specifically operate as a switching module. The load break switch may be configured to switch an electrical load. The load break switch may include at least one arc extinguishing module.

[0079] A switching operation and / or cable disconnection operation by the switching device can be triggered upon or (shortly after) detection of an indication of anchor connection failure. The time period can be at least less than 10 seconds, in particular less than 5 seconds, and particularly preferably less than 1 second. In other words, the switching device can preferably be configured to immediately (i.e., in particular within a time period of less than 1 second) disconnect the electrical connection upon or after detection of an indication of anchor connection failure.

[0080] According to a preferred embodiment of the offshore structure according to the present application, the detection mechanism may comprise at least one position sensor, which may be configured to detect the (instantaneous) position of the floating offshore structure.

[0081] The detection mechanism can include at least one position estimation module that can be configured to detect an indication of anchor connection failure based on the detected position and a predetermined range of acceptable positions.

[0082] The at least one location sensor may in particular be a satellite-based location sensor, for example a GPS sensor, a Galileo sensor, or the like.

[0083] In particular, the at least one position sensor may be configured to substantially continuously detect the instantaneous geographic position of the offshore structure.

[0084] The detected positions or detected position data, particularly in the form of geographic coordinates (e.g. GPS data), may be (continuously) provided to a position assessment module, which is configured to assess the detected positions in order to detect indications of anchor connection failure.

[0085] Preferably, the allowable (geographical) position range of the floating offshore structure is predetermined. In particular, the allowable position range can be determined before and / or during the installation of the offshore structure. In particular, the allowable position range defines the maximum movement radius of the floating offshore structure anchored to the seabed by at least one anchor connection, and can vary depending on parameters such as the length of the at least one anchor connection (e.g., more than 1000 m), the number of anchor connections, and / or the length of the buffer provided for the at least one subsea power cable.

[0086] The allowable position range may be equal to the maximum movement radius or, preferably, slightly (e.g., 5%) larger than it. The allowable position range specifically ensures that small position deviations, caused not only by measurement inaccuracies but also by weather conditions at the installation site, do not lead to the triggering of the switching device. Only larger deviations that may endanger the subsea power cable lead to the triggering of the switching device. The allowable position range may specifically be defined by limiting position data (e.g., geographic coordinates such as GPS coordinates). As long as the detected position data of the offshore structure is within the allowable position range, it can be assumed that at least one anchor connection is intact or not damaged. In this case, the current is not interrupted and the subsea power cable is not mechanically disconnected by the switching device.

[0087] On the other hand, if the detected position data of the offshore structure is outside the acceptable position range, an event or parameter may be detected that indicates that at least one anchor connection is (potentially or actually) broken.

[0088] In a variant of the present application, it may be provided that the switching device is triggered in the described manner only if the detected position of the offshore structure is outside the acceptable position range for a certain (predetermined) period of time (for example between 0.5 and 10 seconds). In the event that the detected position of the offshore structure is again within the acceptable range before the stipulated period has elapsed, the switching device may not be triggered.

[0089] According to a further embodiment of the (floating) offshore structure according to the present application, the detection mechanism may comprise at least one anchor connection structural sensor configured to detect at least one anchor connection structural parameter of the anchor connection. The detection mechanism may comprise at least one anchor connection structural evaluation module configured to detect indications of anchor connection failure based on the at least one detected anchor connection structural parameter and at least one predetermined allowable anchor connection structural parameter range.

[0090] The at least one anchor connection structure sensor specifically includes: - at least one electrical sensor configured to detect at least one electrical parameter of an electrical conductor being guided at least partially along the anchor connection; - at least one optical sensor configured to detect at least one optical parameter of a light guide guided at least partially along the anchor connection; and - at least one mechanical sensor configured to detect at least one mechanical parameter of a measuring rope that is guided at least partially along the anchor connection; and The compound may be selected from the group comprising:

[0091] The electrical sensor may be part of an electrical sensor arrangement. The electrical sensor arrangement may further comprise an electrical (measurement) conductor, e.g., having a forward line and a return line. In one embodiment, the offshore structure may comprise at least one electrical sensor arrangement.

[0092] The forward line of the electrical conductor can preferably extend from the end of the anchor connection portion connected to the anchor connector to the other end of the anchor connection portion attached to the anchor. The return line can continue on from the forward line and extend from the other end of the anchor connection portion to the end of the anchor connection portion connected to the anchor connector. An electrical sensor can be connected to the forward line and the return line.

[0093] The conductors may be arranged in the anchor connection in such a way that if the anchor connection breaks, the conductors also break (at least approximately simultaneously). In the case of an anchor rope, for example, the conductors may be integrated into the anchor rope. In the case of an anchor chain, the conductors may for example be guided through eyelets attached to the chain links.

[0094] Specifically, the electrical sensor may include a generator configured to apply a specific voltage and / or current to the electrical conductor, and may further include at least one measurement module for detecting, specifically measuring, at least one electrical parameter (e.g., voltage, current, magnetic field, electric field, etc.) resulting from the electrical parameter applied by the generator and the state of the electrical conductor (e.g., cracked or not).

[0095] The breakdown of the electrical conductor may cause a detectable change in at least one sensed electrical parameter, specifically, the breakdown of the electrical conductor may cause a change in the sensed electrical parameter such that the sensed electrical parameter (value) is no longer within a specified range of acceptable electrical parameters.

[0096] Specifically, the acceptable electrical parameter range defines a parameter range of a measured electrical parameter (e.g., voltage, current, magnetic field, electric field, etc.) within which the electrical conductor is intact or free of cracks. Specifically, at least one electrical limit parameter value may be predetermined.

[0097] As long as the detected electrical parameter value of the at least one detected electrical parameter is within an acceptable parameter range, it can be assumed that the at least one anchor connection is intact. No triggering of the switching device by sending a disconnect command occurs. On the other hand, if the at least one detected electrical parameter value is outside the acceptable parameter range, an event or parameter can be detected that indicates that the at least one anchor connection is (potentially or actually) broken or disconnected (or is at risk of immediate breakage with a high probability (>95%)). The switching device is then directly triggered.

[0098] Further, an optical sensor mechanism may be provided, which may include an optical sensor and additionally at least one light guide. The offshore structure may include the optical sensor mechanism (and specifically one anchor connection monitored thereby).

[0099] In particular, the light guide may be a linear condition sensor. The light guide may comprise at least one optical fiber, which may be surrounded by a protective layer. In particular, the light guide may be configured to allow detection of at least one optical parameter indicative of at least the mechanical and / or structural condition of the anchor connection.

[0100] For example, vibrations (or acoustic emissions) of anchor connections can be detected, which can then be evaluated to draw conclusions about the mechanical or structural condition of the anchor connections of the offshore structure.

[0101] In particular, the light guide can be integrated into the anchor connection and can for example be at least (radially) surrounded or enclosed by the (outer) sheath of the anchor rope. Alternatively or additionally, the light guide can be guided along the anchor connection by guiding means (e.g. eyelets).

[0102] Preferably, the light conductor can extend substantially along the entire anchor connection (when viewed in the longitudinal direction of the anchor connection), in other words, at least one light conductor can preferably extend substantially from a first end of the anchor connection attached to the anchor connection to the other end of the anchor connection, the other end being connected to or comprising an anchor (e.g., a foundation).

[0103] The optical sensor can include at least one measurement signal generator. The measurement signal generator can be configured to provide an optical measurement signal to at least one light conductor of the anchor connection being monitored. The sensor can include an optical measurement module configured to receive and specifically evaluate a sensor signal generated in response to the optical measurement signal of the light conductor. Specifically, the sensor signal can be based on the measurement signal and the state of the light conductor, and therefore the state of the anchor connection (e.g., cracked or not). By evaluating the sensor signal, a broken anchor connection can be detected.

[0104] The optical sensor can be operated in particular according to the OTDR method. For example, the measurement signal generator can supply at least one light pulse, in particular a laser pulse (for example having a duration of 3 ns to 20 μs), to the light guide as a measurement signal. In particular, the measurement module can measure backscattered light as a sensor signal over time. The (continuously) detected optical parameter can in particular be a sensor signal in the form of a detected reflection parameter, for example a backscattered light parameter or a parameter determined therefrom.

[0105] The light pipe can be attached to the anchor connection such that if the anchor connection breaks, the light pipe also breaks (at least substantially simultaneously). Breaking the light pipe can cause a detectable change in at least one optical parameter. Specifically, breaking the light pipe can cause a change in the detected optical parameter such that the detected optical parameter (value) is no longer within a predetermined acceptable optical parameter range.

[0106] In particular, the allowable optical parameter range defines an optical parameter range within which the light guide and therefore at least one anchor connection is intact or crack-free. In particular, at least one optical limit parameter value may be predetermined.

[0107] As long as the detected optical parameter value of the at least one detected optical parameter is within an acceptable parameter range, it can be assumed that the at least one anchor connection is intact. No triggering of the switching device by sending a disconnect command occurs. On the other hand, if the at least one detected optical parameter value is outside the acceptable parameter range, an event or parameter can be detected that indicates that the at least one anchor connection is (potentially or actually) broken (or is at risk of immediate breakage with a high probability (>95%)).

[0108] Specifically, the optical evaluation module can be configured to (continuously) compare the detected optical parameter value with an acceptable parameter range, and can trigger a switching device if the detected parameter value is determined to be outside the acceptable position range.

[0109] Alternatively or additionally, a mechanical sensing mechanism can be provided, comprising a mechanical sensor and at least one measuring rope, which can extend, for example, from one end of the anchor connection to the other end of the anchor connection, in particular extending parallel to the anchor connection.

[0110] The measuring rope can be attached to the anchor connection in such a way that if the anchor connection breaks, the measuring rope also breaks. Before the break, the tension in the measuring rope detectable by the mechanical sensor and / or the distance traveled by the measuring rope detectable by the mechanical sensor may change, specifically due to the broken anchor connection, which can be detected by the mechanical sensor and evaluated by the mechanical evaluation module. Specifically, the break in the anchor connection causes a detectable change in the detected machine parameter (value), such that the detected machine parameter (value) no longer lies within a specified range of acceptable optical parameters.

[0111] Specifically, the allowable mechanical parameter range defines a parameter range (e.g., maximum allowable stress range, maximum allowable movement range, etc.) within which at least one anchor connection remains intact or unbroken. Specifically, at least one optical limit parameter value (e.g., stress limit, movement limit) can be defined.

[0112] As long as the detected machine parameter value of the at least one detected machine parameter is within an acceptable parameter range, it can be assumed that the at least one anchor connection is intact. No triggering of the switching device by sending a disconnect command occurs. On the other hand, if the at least one detected machine parameter value is outside the acceptable parameter range, an event or parameter can be detected that indicates that the at least one anchor connection is (potentially or actually) broken (or at risk of immediate breakage with a high probability (>95%)).

[0113] The mechanical evaluation module may in particular be configured to (continuously) compare the detected machine parameter value with an acceptable parameter range, and if the detected parameter value is determined to be outside the acceptable parameter range, the switching device may be (immediately) triggered in the described manner.

[0114] A further aspect of the present application is a messenger line system comprising at least one buoy (associated with an offshore structure (as described above)), and at least one messenger line (as described above), a first end of the messenger line securable to the subsea power cable, and a further end of the messenger line secured to the buoy.

[0115] A further aspect of the present application is a subsea power cable system. The subsea power cable system comprises at least one subsea power cable (as described above). The subsea power cable system comprises at least one messenger line (as described above), in particular at least one messenger line system (as described above). A first end of the messenger line is secured to the subsea power cable.

[0116] A further aspect of the present application is a power generation system, the power generation system comprising at least one offshore structure (as described above), the power generation system comprising at least one subsea power cable system (as described above).

[0117] In particular, the power generation system comprises two or more subsea power cable assemblies and / or two or more offshore structures.

[0118] Preferably, the power generation system may be a floating offshore wind power generation system that can be installed and floatable. Specifically, the floating offshore wind power generation system may include two or more floating wind turbines connected via an undersea power cable. The power generation system may also be a floating offshore photovoltaic system that can be installed and floatable, or a floating offshore hydrogen production system that can be installed and floatable. It is understood that the aforementioned systems may be combined. For example, an offshore wind energy system may include at least one photovoltaic device and / or at least one hydrogen production device.

[0119] The features of the offshore structure, the messenger line arrangement, the subsea power cable arrangement, and the power generation system may be freely combined with one another. In particular, the features of this specification and / or the dependent claims may be inventive in their own right, either separately or in free combination with one another, even when the features of the dependent claims are wholly or partially avoided.

[0120] These and other aspects of the present patent application will become apparent from and be described with reference to the following figures: It is understood that the features of the present application and its exemplary embodiments, as presented above, are disclosed in all possible combinations with each other. [Brief explanation of the drawings]

[0121] [Figure 1] 1 is a schematic diagram of one embodiment of an offshore structure according to the present application. [Figure 2] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application; [Figure 3A] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application in normal operating condition; [Figure 3B] FIG. 3B is a schematic diagram of the embodiment of FIG. 3A with the subsea power cable in a broken state. [Figure 4] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application; [Figure 5] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application; [Figure 6] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application; [Figure 7] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application; [Figure 8] 1 is a schematic diagram of a further embodiment of an offshore structure according to the present application; DETAILED DESCRIPTION OF THE INVENTION

[0122] Like reference numerals refer to like elements in the various figures. Furthermore, z represents the vertical direction and x represents the horizontal direction.

[0123] In the following embodiments, an offshore wind turbine is shown as the offshore structure, although the following description may be applied to other offshore structures, such as offshore photovoltaic structures, offshore hydrogen production structures, etc.

[0124] FIG. 1 shows a schematic diagram of an embodiment of a (non-floating) offshore structure 100 according to the present application.

[0125] The offshore structure 100 comprises a foundation 106 (e.g., a monopile anchored to the seabed 124), which is configured to support an offshore device (e.g., a turbine tower with a nacelle) comprising at least one electric device 104 (e.g., a generator). The offshore device is specifically a power generation device, which in this example is a wind turbine. The wind turbine is configured to convert wind kinetic energy into electrical energy. The electric device 104 is electrically connected to at least one subsea cable connector 102.

[0126] In the illustrated installation of the offshore structure 100, a subsea power cable 108 (e.g., a medium or high voltage cable) is connected to the subsea cable connector 102 via a cable connector 112 in the form of a plug 112 on the subsea power cable 108. In this example, generated electrical energy can be supplied from the electrical device 104 to the subsea power cable 108 via the subsea cable connector 102. Energy flow can alternatively or additionally occur in the opposite direction.

[0127] In this embodiment, the plug 112 may include a frangible link 120. In other variations, the frangible link may be located downstream of the plug 112. The frangible link 120 serves to provide a defined break area when a force applied to the subsea cable 108 is great enough to cause the subsea cable 108 to break.

[0128] For example, the subsea power cable 108 may include three-phase conductors for transmitting electrical power. Additionally, the subsea power cable 108 may incorporate at least one optical fiber as an (optical) communication conductor. It is understood that the subsea power cable 108 may include additional cable elements, such as at least one insulation layer, at least one shielding layer, at least one armor layer, an outer jacket, a filler material, and / or the like.

[0129] According to the present application, the offshore structure comprises at least one messenger line 114, for example made from steel and / or fiber reinforced plastic, in particular carbon fiber reinforced polymer, glass fiber reinforced polymer, and / or aramid fiber reinforced polymer.

[0130] A first end 101 of the messenger line 114 is anchored to the subsea power cable 108 and a further end 103 of the messenger line 114 is anchored to the offshore structure 100 .

[0131] Preferably, the first end 101 of the messenger line 114 is fixed to the subsea power cable 108 below or behind the weak link 120 (starting from the subsea cable connector 102). In particular, the first end 101 of the messenger line 114 is fixed in a first end region 110 of the subsea power cable 108, the (cable) length of which is specifically between 0 and 40 m (starting from the subsea cable connector 102), particularly preferably between 0 and 20 m.

[0132] In this embodiment, the first end 101 of the messenger line 114 is secured to the plug 112 via at least one securing module 116. In this exemplary case, the securing module is an eyelet 116. It is to be understood that in other variations, the securing module may be at least one eyelet attached to the subsea power cable, in particular the cable sheath, at least one additional sheath into which the first end of the messenger line is incorporated, or at least one Chinese finger into which the first end of the messenger line is incorporated.

[0133] As already explained, the further end 103 of the messenger line 114 is fixed to the offshore structure, in particular to the structural elements 106, 118. In this case, the further end 103 of the messenger line 114 is fixed to the foundation 106 of the offshore structure 100, in particular to the foundation wall 118, for example via an eyelet. In other variations of the present application, other fixing modules can be used to fix the further end 103 of the messenger line 114 to the structural element. Furthermore, in other variations of the present application, the further end 103 of the messenger line 114 can be fixed to another structural element, such as a hang-off of the offshore structure 100, an airtight deck of the offshore structure 100, a hollow structure (e.g., a J-tube) configured to guide the subsea power cable from the subsea cable connector along the offshore structure, or at least one buoy associated with the offshore structure 100 (see, for example, FIG. 2 ).

[0134] By providing the messenger line 114, it is ensured that a link still exists between the offshore structure 100 and the subsea power cable 108 even if the subsea power cable 108 is damaged.

[0135] It is noted that reference number 122 represents the average waterline.

[0136] Figure 2 shows a schematic diagram of a further embodiment of a (floating) offshore structure 200 according to the present application. To avoid repetition, the following will essentially describe only the differences between the embodiment of Figure 1 and the embodiment of Figure 2. For other elements of the offshore structure 200, reference is made to the previous embodiment.

[0137] In this embodiment, the offshore structure 200 shown in an installed state is a floating offshore structure 200. Here, the offshore structure 200 comprises a floating foundation 206 having at least one floating body 205.

[0138] As can be seen, the illustrated offshore wind turbine 200 includes two subsea cable connectors 202, each connected to a subsea power cable 208. In this example, the subsea power cables 208 extend from the subsea cable connectors 202, preferably in an S-shape, to the surface of the seabed 224. To this end, at least one buoyant body 246 may be provided, and in particular may be attached to the subsea power cables 208.

[0139] As further shown in FIG. 2, at least one subsea power cable 208 is laid on the subsea floor 224 at a particular depth range and extends to further structures (not shown) of the power generation system 215, such as further buoyant or non-buoyant offshore or onshore structures.

[0140] The power generation system 215 comprises at least one offshore structure 200 and at least one subsea cable system 213. The subsea cable system 213 may comprise at least one messenger line 213 and at least one subsea power cable 208.

[0141] Furthermore, the floating offshore structure 200 includes at least one anchor connector 240. In this example, three anchor connectors 240 are provided. In this embodiment, an anchor connection part 242 is attached to each anchor connector 240. Specifically, the anchor connection part 242 is part of the mooring mechanism 238. The offshore structure 200 can include at least one mooring mechanism 238.

[0142] Specifically, the mooring arrangement 238 includes at least one anchor connection portion 242 and an anchor 244. In the illustrated installed and operating condition of the floating offshore structure 200, the anchor 244 of the mooring arrangement 238 is at least partially anchored to the subsea floor 224. A first end of the anchor connection portion 242 is attached to the anchor connector 240, and the other end of the anchor connection portion 242 is attached to the anchor 244.

[0143] Further, the offshore structure 200 comprises at least one messenger line 214, here two messenger lines 214. A respective first end 201 of each messenger line 214 is fixed to a respective subsea power cable 208 (e.g., via an eyelet 216 attached to the cable sheath in the cable end region), and a respective further end 203 of each messenger line 214 is (indirectly) fixed to the offshore structure 200.

[0144] In this example, there is provided at least one buoy 232 associated with the offshore structure 200 (e.g., a respective buoy 232 for each subsea power cable 208). This specifically means that at least one buoy 232 is permanently located within a specific proximity (e.g., a radius of x meters) of the (installed) offshore structure 200 at the installation location. Specifically, the offshore structure 200 includes at least one buoy 232.

[0145] As can be seen, the further end 203 of the messenger line 214 is secured to a buoy 232. Each buoy 232 may be anchored to the seabed via a buoy rope (or chain) 234 and a buoy anchor 236. It is understood that other securing means may be used. It is further understood that only one buoy may be provided for two or more subsea power cables.

[0146] The messenger line system 211 includes at least one buoy 232 and at least one messenger line 214 .

[0147] Additionally, at least one subsea power cable 208 may be equipped with a tracking transmitter 207 (described above), which is preferably located below a fixed point on the further end 203 of the messenger line 214 (starting from the connector 202).

[0148] It is to be noted that according to a variant of the present application, optionally at least one inflatable float (not shown) having at least one inflatable bladder configured to inflate upon receipt of a trigger command can be attached to the subsea power cable as previously described herein.

[0149] FIG. 3A shows a schematic diagram of a further embodiment of an offshore structure 300 according to the present application in normal operating conditions, i.e., without any break in the subsea power cable 308 .

[0150] The illustrated embodiment is similar to the embodiment of Figure 2. The main difference is that each messenger line 314 is not connected to a buoy associated with the floating offshore structure 300. Instead, each further end 303 of each messenger line 314 is connected to a floating foundation 306 (wall).

[0151] Figure 3B illustrates the embodiment of Figure 3B in a broken state for the subsea power cable 308. As can be seen in Figure 3B, at least one subsea power cable 308 of the floating offshore structure 300 has broken (at a weak link) due to a broken anchor connection 342. The broken anchor connection 342 may cause the floating offshore structure to drift (indicated by the arrow) from its original installed position (shown in Figure 3A) to the drifted position shown in Figure 3B.

[0152] The length of at least one messenger line 314 of the floating offshore structure 300 is preferably designed to be at least greater than the maximum distance that the floating offshore structure could potentially move if one of the anchor connections 342 of the floating offshore structure 300 were to break.

[0153] Figure 4 shows a schematic diagram of a further embodiment of an offshore structure 400 according to the present application. To avoid repetition, the following essentially describes only the differences between the previous embodiment and the embodiment of Figure 4. In particular, it is noted that for the sake of overview, certain details of the floating offshore structure 400, such as subsea power cables, messenger lines, anchor connections, etc., have been omitted.

[0154] The detection mechanism 450 of the floating offshore structure 400 comprises at least one position sensor 458, at least one position evaluation module 460, and at least one memory module 452. The at least one position sensor 458 is specifically configured to detect (specifically measure) the (instantaneous) geographic position of the floating offshore structure 400. The at least one position sensor 458 is specifically a satellite-based position sensor 458 (e.g., a GPS sensor, a Galileo sensor, etc.). The satellites 449 can continuously transmit encoded signals. The position sensor 458 can calculate the instantaneous position of the floating offshore structure 400 from information contained in the signals.

[0155] In particular, the at least one position sensor 458 is configured to substantially continuously detect or calculate the instantaneous position of the buoyant offshore structure 400 .

[0156] The position assessment module 460 can be configured to assess the detected position, specifically to detect the presence of an indication of anchor connection failure. Specifically, the detection of the indication of anchor connection failure is based on the detected geographic position of the floating offshore structure 400 and a predetermined allowable geographic position range. Specifically, the position range or corresponding position data can be stored in the memory module 452. The memory module 452 can be accessed by the position assessment module 460.

[0157] Specifically, the allowable geographical location range is the maximum range of movement of the floating offshore structure 400 in its installed state without damaging the anchor connections. This range is indicated by dashed line 462 in FIG. 4. Specifically, for example, if one of the anchor connections is damaged, the maximum range of movement of the floating offshore structure 400 increases, and therefore the floating offshore structure 400 may move outside of the area 462. Therefore, a position monitoring system can be used to reliably detect signs of anchor connection damage.

[0158] In particular, the allowable position range may vary depending on parameters such as the length of the at least one anchor connection, the number of connected anchor connections, the buffer length of the at least one subsea power cable provided, and / or the like. For example, the longer the anchor connection or the greater the water depth at the installation location of the offshore structure 400, the greater the maximum range of motion of the floating offshore structure 400.

[0159] The subsea power cable may have a buffer of a corresponding length, such as having an S-shaped path as shown in Figure 2. When the offshore structure 400 moves within the maximum range of movement, it can be ensured that the subsea power cable is not damaged.

[0160] The detected geographic location, in particular in the form of geographic coordinates (e.g. GPS data), is here (continuously) provided to a location evaluation module 460. The location evaluation module 460 can (continuously) compare the provided location data with an acceptable location range, which may also be defined by the location data.

[0161] If the detected position data is within or satisfies the acceptable position range (i.e., the offshore structure 400 is located within the range 462), it can be determined that at least one anchor connection is intact, and the switching device 456 is not triggered.

[0162] On the other hand, if the position data of the offshore structure 400 is outside the acceptable position range (in this case the offshore structure 400 is located outside the range 462, e.g., at position X), an event or parameter may be detected that indicates that at least one anchor connection is (potentially or actually) broken or disconnected (or is about to break).

[0163] If the detected position of the floating offshore structure 400 is determined to be outside the range of acceptable positions, the switching device 456 may be preferably immediately triggered or activated. Upon detection, and in particular upon detection of an indication of anchor connection failure, an electrical disconnection of at least the electrical connections to the subsea power cables is performed by the switching device 456. Preferably, a corresponding electrical disconnection is performed for all subsea power cables connected to the offshore structure 400. In other words, at least one subsea power cable is de-energized.

[0164] Specifically, in addition to electrical disconnection by the switching device 456, the switching device may mechanically disconnect at least one subsea power cable upon the described detection of an indication of anchor connection failure.

[0165] Figure 5 shows a schematic diagram of a further embodiment of a floating offshore structure 500 according to the present application. To avoid repetition, essentially only the differences from the already shown embodiments will be described below. Otherwise, reference is made to the description of Figures 1 to 4. It is particularly noted that certain details have been omitted to allow for an overview. For ease of reference, only one mooring mechanism 538 and one subsea power cable 508 are shown as examples.

[0166] The illustrated floating offshore structure 500 comprises a detection mechanism 550. In this case, an electric sensor 561 may be provided, formed by the electric detection mechanism 550 and an electric evaluation module 568. In particular, the electric sensor 561 comprises a generator 566 and a measurement module 570.

[0167] In the present example, an anchor chain 542 is provided as the anchor connection 542. In a variant of the present application, an anchor rope can also be provided as the anchor connection.

[0168] Furthermore, in this embodiment, an electric sensor mechanism may be provided, which may be formed by an electric sensor 561 and at least one electric (measuring) conductor 574. The floating offshore structure 500 may comprise at least one electric sensor and / or at least one mooring mechanism 538.

[0169] The conductor 574 can be guided at least partially along the anchor connection portion 542. As can be seen in FIG. 5 , in this case, the conductor 574 is guided along the entire length of the anchor connection portion 542, i.e., from a first end of the anchor connection portion 542 connected to the anchor connector 540 to the other end of the anchor connection portion 542 connected to the anchor 544. Specifically, for this purpose, a plurality of eyelets 572 can be disposed in the anchor connection portion 542. The conductor 574 can be guided through the eyelets 572, with a first end of the conductor 574 connected to the detection mechanism 550 and the other end of the conductor 574 connected to the anchor 544. Specifically, the other end of the conductor 574 can extend into the anchor 544 so that a portion of the conductor 574 always remains within the anchor 544 when the conductor 574 is disconnected from the anchor 544.

[0170] The electrical conductor 574 may include an insulator in the form of a protective layer, specifically a forward line and a return line electrically isolated from each other. A first end of the forward line may be connected to the generator 566, and the other end of the electrical conductor 574 may be connected to the other end of the return line, the first end of which may be connected to the generator 566, specifically forming a closed circuit. Furthermore, a measurement module 570 may be coupled to the first ends of the forward line and the return line to measure electrical parameters.

[0171] Specifically, generator 566 is configured to apply a particular voltage and / or current to electrical conductor 572. For example, a particular voltage can be applied to the forward line and the return line. Specifically, measurement module 570 is configured to detect, and specifically measure, at least one electrical parameter (e.g., voltage, current, magnetic field, electric field, etc.) present in electrical conductor 574. For example, measurement module 570 can measure current.

[0172] Specifically, failure of anchor connection 542 also results in failure of electrical conductor 574. Failure of electrical conductor 574 results in a measurable change in an electrical parameter present in electrical conductor 574. Specifically, an acceptable electrical parameter range may be predetermined, which may vary depending on, among other things, the (predetermined) electrical parameter, the resistance of electrical conductor 574, and / or the length of electrical conductor 574.

[0173] The allowable electrical parameter range can define a parameter range within which at least one anchor connection 542 is intact. As long as the detected electrical parameter value of at least one detected electrical parameter is within the allowable parameter range, e.g., if the detected electrical parameter value does not exceed (or is below) a limit parameter value, it can be assumed that at least one anchor connection 542 is intact. On the other hand, if at least one detected electrical parameter value is outside the allowable parameter range, e.g., if the detected electrical parameter value exceeds (or is below) a limit parameter value, an event or parameter indicating (potentially or actually) damage (or impending damage) to at least one anchor connection 542 can be detected. At that time, the switching device 556 can be triggered in the manner described above.

[0174] Figure 6 shows a schematic diagram of a further embodiment of a floating offshore structure 600 according to the present application. To avoid repetition, essentially only the differences from the already shown embodiments will be described below. Otherwise, reference is made to the description of Figures 1 to 5. It is particularly noted that certain details have been omitted to allow for an overview. For ease of reference, only one mooring mechanism 638 and one subsea power cable 608 are shown by way of example.

[0175] Specifically, instead of the electrical sensor of FIG. 5, an optical sensor 671 is provided as the anchor connection structure sensor.

[0176] In this embodiment, the optical sensor 671 formed by the optical detection mechanism 650 comprises a measurement signal generator 680 and a measurement module 678. Furthermore, the detection mechanism 650 can comprise an optical evaluation module 676.

[0177] Further, in this case, at least one anchor connection 642 is formed as an anchor rope 642. The anchor rope 642 can incorporate a light conductor 682. As can be seen, the illustrated light conductor 682 extends from a first end of the anchor rope 642 attached to the anchor connector 640 to the other end of the anchor rope 642 attached to the anchor 644. Specifically, the first end of the light conductor 682 can be coupled to the sensor 671. The sensor 671 and the light conductor 682 can form an optical sensor mechanism. Specifically, the other end of the light conductor 682 can extend into the anchor 644 such that if the light conductor 682 breaks from the anchor 644, a portion of the light conductor 682 always remains with the anchor 644.

[0178] The measurement signal generator 680 is here configured to provide an optical measurement signal to at least one light conductor 682 of the anchor connection 642 being monitored. The light measurement module 678 is here configured to receive and, in particular, evaluate a sensor signal generated in response to the optical measurement signal of the light conductor 682. In particular, the evaluation can be based on the measurement signal and the sensor signal causing the measurement signal to determine whether the anchor connection 642 is broken or not.

[0179] The illustrated optical evaluation module 676 can be configured to detect a broken anchor connection 642 based on at least one detected optical parameter and at least one predetermined acceptable optical parameter range.

[0180] Specifically, the optical sensor 671 is operated according to the OTDR method. For example, the measurement signal generator 680 can provide at least one laser pulse (e.g., having a duration of 3 ns to 20 μs) to the light conductor 682 as the measurement signal. Specifically, the measurement module 678 can measure the backscattered light as the sensor signal over time. The time dependence of the sensor signal can, for example, be converted into a position dependence, allowing a spatially resolved determination of the state of the mechanical structure of the anchor connection 642 (e.g., based on vibration data, audio data, etc. obtained from the measurement signal). Specifically, the (continuously) detected optical parameter is the sensor signal, which can be, for example, a detected reflection parameter, such as a backscattered light parameter or a parameter determined therefrom.

[0181] Light conductor 682 can be attached to, and particularly can be incorporated into, anchor connection 642 such that if anchor connection 642 breaks, light conductor 682 also breaks. Breaking of light conductor 682 can cause a detectable change in at least one sensed optical parameter. Specifically, breaking light conductor 682 can cause a change in the sensed optical parameter such that the sensed optical parameter (value) is no longer within a predetermined acceptable optical parameter range.

[0182] In particular, the acceptable optical parameter range defines a parameter range within which at least one anchor connection 642 is intact. In particular, at least one optical limit parameter value may be predetermined.

[0183] As long as the detected optical parameter value of the at least one detected optical parameter is within an acceptable parameter range, i.e., specifically, does not exceed (or is below) an optical limit parameter value, it can be assumed that the at least one anchor connection 642 is intact. On the other hand, if the at least one detected optical parameter value is outside the acceptable parameter range, it can be assumed or detected that the at least one anchor connection 642 is (potentially or actually) damaged (or at high risk of immediate damage), for example, if the optical limit parameter value is exceeded (or is below). At that time, the switching device 656 can be triggered in the manner described above (see, e.g., FIG. 4 ).

[0184] Figure 7 shows a schematic diagram of a further embodiment of a floating offshore structure 700 according to the present application. To avoid repetition, essentially only the differences from the previously shown embodiments will be described below. Otherwise, reference is made to the description of Figures 1 to 6. It is particularly noted that certain details have been omitted to allow for an overview. Also, for ease of reference, only one mooring mechanism 738 and one subsea power cable 708 are shown as examples.

[0185] Specifically, in the illustrated embodiment, a mechanical sensor 775 is provided as the anchor connection structure sensor instead of the electrical sensor of Figure 5 or the optical sensor of Figure 6. In variations of the present application, different sensors can be provided.

[0186] In this example, the anchor connection is a combination of an anchor chain 742.1 and an anchor rope 742.2. According to the preferred embodiment shown, e.g., using eyelets 772 as guiding elements, a measuring rope 790 is guided along the entire length of the anchor connections 742.1, 742.2. A first end can be coupled to a mechanical sensor 775. The sensor 775 and the measuring rope 790 can form a mechanical sensor. The other end of the measuring rope 790 can be attached to the anchor 744.

[0187] In this case, the mechanical sensor 775 formed by the mechanical detection mechanism 750 may comprise a mechanical sensor module 788 coupled to the measuring rope 790. In particular, the mechanical sensor module 788 is configured to detect at least one mechanical parameter of the measuring rope 790.

[0188] In this embodiment, the detection mechanism 750 further comprises at least one mechanical evaluation module 786. The mechanical evaluation module 786 may be configured to detect a broken anchor connection 742.1, 742.2 based on at least one detected mechanical parameter and at least one predetermined acceptable mechanical parameter range.

[0189] The measuring rope 790 can be attached to the anchor connections 742.1, 742.2 such that a break in the anchor connections 742.1, 742.2 will result in a break in the measuring rope 790. Prior to a break in the measuring rope 790, the tension in the measuring cable detectable by the mechanical sensor module 788 and / or the travel distance of the measuring rope 790 detectable by the mechanical sensor module 788 may change, specifically due to the broken anchor connections 742.1, 742.2. This can be detected by the mechanical sensor module 788 and evaluated by the mechanical evaluation module 786. Specifically, the break in the anchor connections 742.1, 742.2 will cause a change in the detected machine parameter such that the detected machine parameter (value) no longer falls within a predetermined acceptable optical parameter range.

[0190] Specifically, the allowable mechanical parameter range defines a parameter range (e.g., maximum allowable stress range, maximum allowable movement range, etc.) within which at least one anchor connection 742.1, 742.2 remains intact. Specifically, at least one mechanical limit parameter value (e.g., stress limit value, movement limit value) may be predetermined.

[0191] As long as the detected machine parameter value of at least one detected machine parameter is within an acceptable parameter range, i.e., specifically, a limit parameter value is not exceeded (or not exceeded), it can be assumed that at least one anchor connection 742.1, 742.2 is intact. On the other hand, if at least one detected machine parameter value is outside the acceptable parameter range, i.e., for example, if a limit parameter value is exceeded (or not exceeded), an event or parameter indicating (potentially or actually) damage (or a high risk of immediate damage) of at least one anchor connection 742.1, 742.2 can be detected. Preferably, the switching device 756 can then be immediately triggered as described above.

[0192] The described embodiments of Figures 1 to 7 can be combined with each other, for example the example embodiment of Figure 4 can be combined with the example embodiment of Figures 5 to 7.

[0193] 8 shows a detailed schematic fragmentary view of a further embodiment of an offshore structure 800 according to the present application, with details such as messenger lines omitted for clarity.

[0194] 8, an offshore structure 800 includes a subsea cable connector 802 coupled with a plug 812 of a subsea power cable, the subsea power cable being guided from the subsea cable connector 802 towards the seabed through a hollow structure (e.g., a J-tube). Also shown is the already-described weak link 820. In this example, the weak link may be located in a hang-off of the offshore structure.

Claims

1. An offshore structure (100, 200, 300, 400, 500, 600, 700, 800), in particular a floating offshore structure (200, 300, 400, 500, 600, 700, 800), at least one subsea cable connector (102, 203, 302, 502, 602, 702, 802) configured to connect a subsea power cable (108, 208, 308, 508, 608, 708, 808) to at least one electrical device (104, 204) of an offshore structure (100, 200, 300, 400, 500, 600, 700, 800); In an offshore structure (100, 200, 300, 400, 500, 600, 700, 800) comprising: The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) further comprises: - at least one messenger line (114, 214, 314, 514, 614, 714) Equipped with a first end (101, 201, 301, 501, 601, 701) of said messenger line (114, 214, 314, 514, 614, 714) is fixed to said subsea power cable (108, 208, 308, 508, 608, 708, 808) and a further end (103, 203, 303, 503, 603, 703) of said messenger line (114, 214, 314, 514, 614, 714) is fixed to said offshore structure (100, 200, 300, 400, 500, 600, 700, 800); An offshore structure (100, 200, 300, 400, 500, 600, 700, 800).

2. the first end (101, 201, 301, 501, 601, 701) of the messenger line (114, 214, 314, 514, 614, 714) is fixed to the subsea power cable (108, 208, 308, 508, 608, 708, 808) in an end region (110) of the first end of the subsea power cable (108, 208, 308, 508, 608, 708, 808) that is connected to the subsea cable connector (102, 203, 302, 502, 602, 702, 802); the length of said end region (110) is between 0 and 40 m, in particular between 0 and 20 m; The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to claim 1.

3. the first end (101, 201, 301, 501, 601, 701) of the messenger line (114, 214, 314, 514, 614, 714) is secured to the subsea power cable (108, 208, 308, 508, 608, 708, 808) at a cable connector (112, 212, 312, 412, 512, 612, 712) of the subsea power cable (108, 208, 308, 508, 608, 708, 808); The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to claim 1 or 2.

4. the subsea power cable (108, 208, 308, 508, 608, 708, 808) comprises a frangible link (120, 220, 320, 420, 520, 620, 720) in the end region (110) of the first end of the subsea power cable (108, 208, 308, 508, 608, 708, 808), and the first end (101, 201, 314, 514, 614, 714) of the messenger line (114, 214, 314, 514, 614, 714) 01, 501, 601, 701) is secured to the submarine power cable (108, 208, 308, 508, 608, 708, 808) downstream of the weak link (120, 220, 320, 420, 520, 620, 720) starting from the submarine cable connector (102, 203, 302, 502, 602, 702, 802) of the offshore structure (100, 200, 300, 400, 500, 600, 700, 800). An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 3.

5. the first end (101, 201, 301, 501, 601, 701) of the messenger line (114, 214, 314, 514, 614, 714) is fixed to the subsea power cable (108, 208, 308, 508, 608, 708, 808) via at least one fixing module (116, 216, 316, 416, 516, 616), and the at least one fixing module (116, 216, 316, 416, 516, 616) at least one eyelet attached to said cable connector (112, 212, 312, 412, 512, 612, 712); at least one eyelet attached to said submarine power cable (108, 208, 308, 508, 608, 708, 808), in particular to the cable sheath of said submarine power cable (108, 208, 308, 508, 608, 708, 808); at least one additional sheath in which said first end (101, 201, 301, 501, 601, 701) of said messenger line (114, 214, 314, 514, 614, 714) is incorporated; at least one Chinese finger incorporating said first end (101, 201, 301, 501, 601, 701) of said messenger line (114, 214, 314, 514, 614, 714); Selected from the group comprising An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 4.

6. - said further end (103, 203, 303, 503, 603, 703) of said messenger line (114, 214, 314, 514, 614, 714) is fixed to said offshore structure (100, 200, 300, 400, 500, 600, 700, 800) by at least one structural element, said at least one structural element comprising: - Hanging off the offshore structure (100, 200, 300, 400, 500, 600, 700, 800), an airtight deck of said offshore structure (100, 200, 300, 400, 500, 600, 700, 800); a hollow structure configured to guide the subsea power cable from the subsea cable connector (102, 203, 302, 502, 602, 702, 802) along the offshore structure (100, 200, 300, 400, 500, 600, 700, 800); - the foundation of the offshore structure (100, 200, 300, 400, 500, 600, 700, 800), at least one buoy associated with said offshore structure (100, 200, 300, 400, 500, 600, 700, 800); Selected from the group comprising An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 5.

7. said messenger lines (114, 214, 314, 514, 614, 714) - metals, especially steel, - Plastic and - fiber-reinforced plastics, in particular carbon-, glass- and / or aramid-fiber-reinforced polymers; made from a material selected from the group comprising An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 6.

8. said submarine power cable (108, 208, 308, 508, 608, 708, 808) comprises at least one tracking transmitter (207); An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 7.

9. The length of the messenger line (114, 214, 314, 514, 614, 714) of the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) is determined based on the water depth at the installation location of the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800), the water depth at the installation location of the floating offshore structure (100, 200, 300, 400, 500, 6 ... the number of anchor connections (242, 342, 542, 642, 742) of the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) and / or the shape of the path of the anchor connections (242, 342, 542, 642, 742) from the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) to the anchors (244, 344, 544, 644, 744) fixed to the subsea floor, the length of the at least one messenger line (114, 214, 314, 514, 614, 714) of the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) is at least greater than the maximum possible distance of movement of the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) in particular when one anchor connection (242, 342, 542, 642, 742) of the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) breaks; An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 8.

10. The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) is a floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800), and the floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) further comprises: at least one anchor connector (240, 340, 540, 640, 740) configured to connect at least one anchor connection (242, 342, 542, 642, 742) for anchoring said floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800) to a subsea floor; at least one detection mechanism (450, 550, 650, 750) configured to detect an indication of anchor connection failure; at least one switching device (456, 556, 656, 756) configured to at least electrically disconnect an electrical connection to said subsea power cable (108, 208, 308, 508, 608, 708, 808) connected to said subsea cable connector (102, 203, 302, 502, 602, 702, 802) upon or after detection of an indication of said anchor connection failure; An offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 9, characterized in that it comprises:

11. - said detection mechanism (450, 550, 650, 750) comprises at least one position sensor (458) configured to detect the position of said floating offshore structure (100, 200, 300, 400, 500, 600, 700, 800); said detection mechanism (450, 550, 650, 750) comprises at least one position assessment module (460) configured to detect an indication of a failure of said anchor connection based on said detected position and a predetermined range of acceptable positions; The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to claim 10.

12. - said detection mechanism (450, 550, 650, 750) comprises at least one anchor connection structure sensor configured to detect at least one anchor connection structure parameter of said anchor connection; said detection mechanism (450, 550, 650, 750) comprises at least one anchor connection structural evaluation module configured to detect an indication of said anchor connection failure based on said at least one detected anchor connection structural parameter and at least one predetermined acceptable anchor connection structural parameter range; said at least one anchor connection structure sensor in particular at least one electrical sensor (561) configured to detect at least one electrical parameter of an electrical conductor (574) guided at least partially along said anchor connection (242, 342, 542, 642, 742); at least one optical sensor (671) configured to detect at least one optical parameter of a light guide (682) guided at least partially along said anchor connection (242, 342, 542, 642, 742); at least one mechanical sensor (775) configured to detect at least one mechanical parameter of a measuring rope (790) guided at least partially along said anchor connection (242, 342, 542, 642, 742); Selected from the group comprising The offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to claim 10 or 11.

13. at least one buoy (232); at least one messenger line (114, 214, 314, 514, 614, 714), wherein a first end (101, 201, 301, 501, 601, 701) of said messenger line (114, 214, 314, 514, 614, 714) is fixable to a subsea power cable (108, 208, 308, 508, 608, 708, 808) and a further end (103, 203, 303, 503, 603, 703) of said messenger line (114, 214, 314, 514, 614, 714) is fixed to said buoy (232); A messenger line mechanism (211) comprising:

14. at least one subsea power cable (108, 208, 308, 508, 608, 708, 808); at least one messenger line (114, 214, 314, 514, 614, 714), in particular a messenger line arrangement (211) according to claim 14, wherein a first end (101, 201, 301, 501, 601, 701) of said messenger line (114, 214, 314, 514, 614, 714) is fixed to said subsea power cable (108, 208, 308, 508, 608, 708, 808); A subsea power cable mechanism (213).

15. at least one offshore structure (100, 200, 300, 400, 500, 600, 700, 800) according to any one of claims 1 to 12, and - at least one subsea power cable system (213) according to claim 14; A power generation system (215) comprising:

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