Stabilizers, subsea systems, and use of stabilizers

Abstract

A stabilization device 22 for a submarine cable unit 18 is disclosed. The stabilization device 22 extends between the seabed 17 and a cable inlet 13 on a submarine structure 11. The stabilization device 22 comprises at least one stabilization base portion 24, 25 and at least one pile element 54 for fixing the stabilization base portion 24, 25 to the seabed 17 or a scour-resistant layer 15. The stabilization device 22 further comprises a first clamping device 27 securely fixed to one end of the at least one stabilization base portion 24, 25. The first clamping device 27 is curved and at least partially surrounds the submarine cable unit 18 and holds the submarine cable unit 18 in the state in which the at least one stabilization device 24, 25 and the submarine cable unit 18 are installed. A second clamping device 28 is securely fixed to the other end of the at least one stabilization base portion 24, 25.

Description

Technical Field

[0001] The present invention relates to a stabilization device and a subsea system for stabilizing a cable and a cable protection system in a subsea environment.

Background Art

[0002] In the fixed offshore wind power industry, a series of state-of-the-art techniques related to cables, such as cable installation and protection, have been developed. For many reasons including cost, the industry has adopted a static cable design for so-called "interarray grids". This is a cable that interconnects individual wind turbines (WTGs) and substations. Also, export cables from offshore substations and landfall cables connecting to onshore substations are based on static cable designs. These static cable designs are operable only for extremely limited movements (i.e., dynamic behavior). Such movements are usually limited to very limited movements during winding and unwinding operations in the manufacturing and installation stages, as well as during the power generation operation stage (usually 20 to 40 years) and the decommissioning stage at the end of the offshore lease.

[0003] The dynamic life of a static cable design is defined by the cable design limits. In repeated motion (dynamic loading), a series of curvature and tension parameters define the fatigue life of the cable design. The more the cable is exposed to dynamic loading (increased curvature and / or increased tension), the shorter its fatigue life.

[0004] It has been demonstrated that in cable laying and operation, difficulties arise when the cable is not protected during handling during pulling-in operations or during operation when exposed to accelerated water particle velocities (tidal currents).

[0005] The most advanced cable protection method in the industry is burying cables in the seabed between foundations. In addition to complying with existing rules and regulations, the industry has also established several standards and recommended practices. Early wind turbines were equipped with J-tubes as standard as cable protection systems, but from an economic standpoint, monopile (J-tubeless) designs that omit J-tubes have been pursued. This method utilizes openings in the monopile wall to mechanically connect the so-called cable protection system.

[0006] The primary purpose of cable protection systems was to stabilize the cables within the system, specifically stabilizing them along their path from the opening of a J-tubeless monopile or the bellmouth of a J-tube to the seabed. However, "stabilization" is a misleading term. In reality, cable protection systems exposed to accelerated water particle velocities are not stable and move. While various bending strain management and limiting solutions within cable protection systems reduce their mobility, they can still move periodically, resulting in the cables housed within being forced to move along with the system.

[0007] Cable protection systems are forced to move along with surrounding water particles accelerated by marine weather conditions (wind, waves, and currents). Until 2020 and 2021, software such as Orcaflex was thought to be able to model these conditions and provide realistic scenarios regarding the scale and impact of water particle flow velocity.

[0008] The cable protection system is constructed in software (Orcaflex or similar software) as a model where the trajectory from the monopile opening or J-tube bell mouth to the seabed contact point or the actual scour prevention structure follows a catenary, and then continues through the scour prevention structure / seabed to the seabed burial point. These forces primarily act on the catenary because water particle velocity is highest at the point closest to the foundation and lowest at the seabed burial point further away from the foundation. The worst-case scenario occurs under the most extreme sea conditions and is represented as the ultimate limit state, namely the maximum tension and the most severe bending stress dynamically generated in the cable protection system.

[0009] This dynamic force exists as a tensile force in the seabed portion of the cable protection system. For the cable protection system to remain in place, an anchor strength greater than the maximum potential tensile force derived from the calculated ultimate limit state is required. This anchor strength is called the "holdback capacity" and requires that a portion of the cable protection system be buried in the seabed. The density, friction, and characteristics of the seabed determine the length of this buried portion. The modeled holdback capacity (the assumed value used in the analysis) assumes that the characteristics of the seabed are known and unchanging (i.e., that the characteristics of the seabed are constant or greater).

[0010] The current procedure essentially follows a flow where the cable protection system supplier conducts an analysis to prove the following (using Orcaflex or similar software):

[0011] (a) The limitations of the cable design (minimum bending radius and tensile force) are not compromised. (b) The fatigue life of the cable exceeds the project's lifecycle (typically, a safety factor of 10 is applied, so a 32-year project requires a minimum cable fatigue life of 320 years).

[0012] Since 2019, there has been an increase in cable protection system failures, and several cable failures have also been discovered. These are due to both environmental and technical factors. Two key environmental factors stand out.

[0013] (1) The acceleration of water particles around the vertical foundation is more severe than predicted by the analysis. Evidence supporting this is the protection of the scour. In recent years, D-90 stones (typically 275 kg in air) have been proposed, but 6-7 years ago, D-30 stones (typically 50 kg in air) were sufficient.

[0014] (2) Another environmental factor, and equally important to this invention, is the characteristics of the seabed. The characteristics of the seabed were largely unknown in the 2010s, at least in the top 2-3 meters of the seabed, and were only revealed through the Cone Penetration Test (CPT) campaign in 2017-2018.

[0015] The Cone Penetration Test (CPT) is an important tool for Cable Burial Risk Assessment (CBRA), primarily focusing on burial depths beneath existing / undeveloped seabed, providing predictions about the minimum depth to which cables can be lowered below undeveloped seabed levels.

[0016] However, the cone penetration test is misleading as an indicator for evaluating the impact of buried cable protection systems on seabed characteristics. This is because the undeveloped seabed from which cone penetration test CPT data is obtained is disturbed during installation and burial activities. Therefore, evaluations leading to the analysis of the buried portion of the cable protection system are based on models that must be set by assuming parameters for soil spring properties and holdback capacity. There is no way to actually verify that these assumed values ​​are not optimally chosen for the analysis to pass.

[0017] In addition to seabed characteristics, installation tolerances further increase uncertainty regarding the relative position of the cable protection system's burial location to the foundation. This amplifies uncertainties already assumed in the best-case scenario (such as the seabed characteristics, the non-finite nature of the soil spring seabed interface, and the unknown precise location of the soil springs during installation).

[0018] In addition to these uncertainties, there are unforeseen future changes that may occur throughout the operational life of the cable protection system. Up until 2021, at least most analyses suggested that the backfill on cable protection systems resembled undeveloped seabed (compressed solid) when buried up to the top of the trench (which, even in the best-case scenario, assumes much higher ball-sting weights than in reality, as well as unrealistic cable protection systems and cable coverings). Furthermore, assumed burial angles were often smaller than expected, leading to the assumption that the anchor strength of cable protection systems was higher than carefully calculated, and even further away from the structures of wind turbines and substations.

[0019] These two environmental conditions promoted and amplified the mobility of the cable protection system in the Scour protection and seabed environments. In other words, analyses previously presented as "conservative models" realistically underestimated the mobility of the cable protection system. As a result, the cable protection system behaves more dynamically, imposing higher curvature and tensile forces on the cable (which shortens the cable's fatigue life and may exceed the limits of the cable design). The increased curvature and tensile forces within the cable protection system further intensify the load on the soil springs of the seabed interface, placing a high force on the holdback capacity. Therefore, the tensile forces within the cable protection system exceed the holdback capacity of the anchor, pulling the buried portion away from its burial position. Consequently, the longer portions of the cable protection system are dynamically affected, transferring higher tensile forces with tighter curvature to the cable.

[0020] Furthermore, a series of technical deficiencies are at play. One of them is the use of bend restrictors. These are strictly defined by the American Petroleum Institute (API) 17, based on the API's recommended practices for flexible elements (Specifications and Recommended Practices for Flexible Pipe Accessories), as being applicable only to static sections (e.g., the "static" portion of a steep or gentle loop-type flexible riser, where the dynamic portion is separated by buoyancy from the surface, and the seabed touchdown portion is the portion not affected by the surface metocean).

[0021] The analysis assumes that the joints of the bending limiting device function like a uniform vertebra. Therefore, the analysis distributes all movement across the entire joint, but in reality, small differences between each link cause the interlocking section with the least friction to act first and most heavily. Next, as the row of bending limiting devices is dragged along the scour protection or the seabed, it rolls. Due to the repeated movement, the initial friction (between links) decreases, so the row of bending limiting devices becomes like a circular wheel. Thus, the friction when rolling along the scour protection or the seabed gradually decreases.

[0022] This movement, coupled with the designers' and analysts' assumption of a "clean seawater environment" within the cable protection system, hinders the understanding that in reality, turbid seawater near the seabed, silt and sand particles act highly abrasive. In reality, as the bending limiter rotates with the highly abrasive mixture of silt and sand, not only the bending limiter itself but also the cables within the cable protection system are worn down from the inside.

[0023] Following the discovery of these failures, the industry, particularly Orsted, has advanced the stabilization of cable protection systems and taken measures to prevent movement between the cable protection system and the cable (Orsted stabilized five wind farms in 2021 and 2022 that employed cable protection system designs based on bending limiters).

[0024] In response to this background, in 2022, the insurance industry for the offshore wind power industry claimed to impose cable protection systems and cable "stabilization" as conditions for issuing new insurance contracts.

Prior Art Documents

Patent Documents

[0025]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0026] Stabilization by rock solves the mobility of the cable protection system in scour protection and on the seabed, but changes the conditions of the cable protection system. The track on the seabed is stabilized, but the catenary (sag curve) part remains in a dynamic environment. Although the mobility of the part of the cable protection system existing under the rock is removed, the characteristics and position of the coil spring model remain uncertain. When the cable protection system is fixed with pins under stabilization, the local bending moment at the fixed part increases. When the cable protection system and the cable are fixed with pins under stabilized ballast, the local bending moment and tensile force at the pinning point and its periphery increase. As a result, not only does the fatigue life of the cable shorten, but the cable protection system may be loaded by uncalculated bending moments.

[0027] Another aspect of cable or cable protection systems and cable stabilization is the cost of stabilization materials and their installation. While the cost of stabilization materials and installation varies, it is estimated to be three to five times the cost of cable protection systems in the North Sea region of Europe. This cost can reach approximately three times in the Americas and about six times in the Asia-Pacific (APAC) region.

[0028] When constructing wind power plants in already challenging offshore logistics operations, stabilization is required relatively quickly after cable installation. This adds risk, complexity, and cost to the installation process. Many developers prioritize heavy machinery work, so delays in stabilization prolong the work and increase the risk of severe fatigue of cable protection systems and cables before they stabilize. [Means for solving the problem]

[0029] Therefore, the object of the present invention is to provide a cable protection system and / or cable stabilization that eliminates risks due to seabed characteristics and changes in the seabed. Furthermore, an object of the present invention is to provide a cable protection system and / or a cable with stabilization equipped with a bending control system, and to eliminate the risk of the cable's fatigue life being compromised. In other words, the objective is to eliminate the risk of cable failure during the cable's operational life.

[0030] Furthermore, another objective is to provide stabilization within the cable pull-in sequence. Another objective is to provide a cable protection system and / or cable stabilization without using ballast material (e.g., rocks, rock filter bags, mattresses, etc.).

[0031] Another objective is to provide a cable protection system and / or cable stabilization without using cranes or lifting operations. Another objective is to provide a cable protection system and / or cable stabilization while avoiding proximity to wind turbines and substations.

[0032] Furthermore, another objective is to provide a wide tolerance for the positioning of cable protection systems and / or cable stabilization devices. These objectives are achieved by using the stabilization device defined in claim 1, the subsea system defined in claim 20, and the stabilization device and subsea system defined in claim 24. Further embodiments of the present invention are defined in the dependent claims.

[0033] Therefore, the following stabilization device is provided. The stabilization device is used for submarine cable units extending between the seabed and the cable entrance of a submarine structure. The cable entrance is located above the seabed. The submarine cable unit consists of a submarine cable with a cable protection system, or a submarine cable alone. The stabilization device is, At least one stabilizing base section, A pile element for anchoring at least one stabilizing base to the seabed, wherein the pile element is driven into the seabed and is adapted to allow at least one stabilizing base to be securely anchored to the seabed, A first clamping device securely attached to one end of at least one stabilizing base, the first clamping device being curved and adapted to at least partially enclose and hold the submarine cable unit when the stabilizing device and the submarine cable unit are installed, A second clamping device securely attached to one end of at least one stabilizing base, the second clamping device being curved and adapted to at least partially enclose and hold the submarine cable unit when the stabilizing device and the submarine cable unit are installed, It is equipped with.

[0034] The first and second clamping devices can be attached to the stabilizing base. The first clamping device may be located closer to the seabed structure than the second clamping device. The first clamping device may be configured to be flexible.

[0035] Preferably, the second clamping device has higher rigidity than the first clamping device. Preferably, at least one stabilizing base portion is provided with at least one through-hole through which a pile element can pass.

[0036] The stabilization device preferably comprises at least one bracket arrangement (structure, arrangement), which comprises at least one through hole for the pile element.

[0037] The pile element may be equipped with an inflating device that applies force toward the seabed to at least one stabilizing base section. The inflatable device is adapted to inflate when the seabed is eroded, and it is preferable that it applies a continuous force toward the seabed to at least one stabilizing base.

[0038] The expansion device may, for example, include a spring element. Furthermore, the expansion device may include a hydraulic element. Furthermore, the inflation device may include an inflation element that expands (swells) in water.

[0039] The pile element is equipped with an adjustment device for adjusting the tension in the spring element, thereby allowing the force applied to at least one stabilizing base to be adjusted.

[0040] Preferably, the stabilization device further includes a cowl unit for controlling the bending of the submarine cable unit. This cowl is curved and surrounds the submarine cable unit at least partially along its circumferential direction. The cowl unit and the submarine cable unit are held together by first and second clamping devices.

[0041] The cowl unit can be further bent along the longitudinal direction of the submarine cable unit, while ensuring that the cable does not bend beyond a predetermined angle. Alternatively, the cowl unit can be substantially straight, but with flexibility on one side, allowing it to bend to conform to the catenary shape of the submarine cable unit after installation.

[0042] The cowl unit is equipped with at least one motion-stopping element (motion arresting element, motion-stopping member) on the side facing the submarine cable unit. This at least one motion-stopping element is pressed against the submarine cable unit.

[0043] The stabilization device comprises a first stabilization base and a second stabilization base, each having at least one through-hole for a pile element. This pile element, by fitting into at least one through-hole, can be driven into the seabed. Thus, the first and second stabilization bases are securely anchored (secured) to the seabed.

[0044] The first stabilization base and the second stabilization base are preferably located on both sides of the submarine cable unit. The first clamping device is preferably securely attached to the first stabilizing base at one end and to the second stabilizing base at the other end. The second clamping device is preferably securely attached to the first stabilizing base at one end and to the second stabilizing base at the other end.

[0045] The first clamping device includes at least one dynamic absorber, one end of which is anchored to the first and / or second stabilizing base and the other end to the cowl unit.

[0046] The first and / or second stabilization base section is provided with multiple through-holes for pile elements. These pile elements fit into each through-hole and can be driven into the seabed. This securely anchors the first and / or second stabilization base section to the seabed by the multiple pile elements.

[0047] Preferably, at least one through-hole is equipped with a guide element to facilitate the entry of the pile element during installation. Pile elements may be adapted to be handled by ROVs (remotely operated vehicles).

[0048] Submarine cable units may be equipped with cable protection devices. Preferably, the cable protection device is positioned to surround the cable. Cable protection devices preferably extend at least through the stabilization device. However, in some cases, they may not extend through the entire stabilization device.

[0049] The underwater structure is preferably firmly attached to the seabed. Furthermore, the following subsea system is provided: This system comprises a subsea structure firmly attached to the seabed and a subsea cable unit extending between the seabed and the cable inlet of the subsea structure. The cable inlet is located above the seabed. The subsea cable unit consists of a subsea cable with a cable protection system, or a subsea cable alone. The subsea system is equipped with the stabilization devices defined above, thereby stabilizing the subsea cable unit. This subsea system may have, or lack, one, some, or all of the additional features described above.

[0050] This subsea system may include multiple stabilization devices pre-positioned along the longitudinal direction of the subsea cable unit. Stabilization devices may be placed on top of a scour protection layer (scour protection layer) already installed on the seabed adjacent to the seabed structure.

[0051] In addition, stabilization devices are sometimes placed directly on the seabed. The seabed structures may be monopiles of wind turbines firmly attached to the seabed, or other seabed structures that are firmly attached to the seabed. Furthermore, the seabed structures may be semi-submersible structures, such as semi-submersible structures that operate in relatively shallow waters up to a depth of 200 to 250 meters.

[0052] Furthermore, a method is provided for stabilizing submarine power transmission cables from offshore wind farms using the stabilization devices and / or submarine systems described above. Therefore, the stabilization device according to the present invention provides a cable protection system and / or a foundation for stably anchoring cables to the seabed (fixed to the foundation of a wind turbine or substation, with or without scour protection). This enables specific and permanent bending stress relief regardless of current and future seabed features and changes. Furthermore, this stabilization device provides calculable bending stress relief without knowing or taking risks related to seabed features and changes.

[0053] This allows the normal seabed position adjustment tolerances during installation (related to foundation, opening height, scour protection, cables, and cable protection systems) to be incorporated and captured within the bending control system and stabilization device.

[0054] Therefore, the invention of this application has at least the following advantages. • Stabilization of the cable protection system is carried out in the scour protection and / or on the seabed. Bending stress is managed by built-in bending stress relaxation.

[0055] Stabilization is performed on the seabed (through the protection of the scaua or the moving seabed). • Bending stress relief and bending control are independent of seabed characteristics (designed bending control is maintained regardless of seabed characteristics) and are not affected by seabed changes (such as movement, erosion, sand waves, and seabed drop).

[0056] Stabilization is achieved without the use of rock (or other ballast material). Stabilization will be carried out while the cables are being installed. • The stabilization unit is designed to be recyclable (it can be retrieved during operation or at the time of disposal for cable replacement or other reasons).

[0057] • Stabilization is applicable to existing (operational) cable protection systems, thus facilitating the above-mentioned operational functions (stabilization with known bending management response). Stabilization is performed using a remotely operated vehicle (ROV) and tool skid, eliminating the need for nearby vessels (resulting in a very low risk of impact on foundations and cable / cable protection systems).

[0058] • Weather windows do not restrict access to the platform. Furthermore, the stabilization device according to the present invention facilitates the following: The stabilization device allows for the isolation of dynamic forces from the catenary portion of the cable protection system (curvature and tensile forces within the cable protection system terminate at the stabilization device). Therefore, the cable protection requirements of the cable protection system from the stabilization device to the burial point are freed from most risks and fatigue problems.

[0059] • This invention reduces the dynamic forces to which the catenary portion of a cable protection system is exposed. • The cable protection system will be subjected to less curvature and lower stress. The cable protection system is supported by a bending control system during landing (touchdown, grounding), i.e., in the stabilization device.

[0060] The tensile force from the cable protection system at the catenary is concentrated within the stabilization device. Therefore, the tensile force is removed from the cable protection system on the seabed. • Curvature and tensile stress on the cable are reduced.

[0061] • Cable fatigue life is extended. • The stabilization device enables type certification with cable protection systems (this allows a wide range of cable designs to have a broad installation tolerance to meet cable fatigue life requirements).

[0062] The stabilization device allows for the use of a flexible structure in the cable protection system, which may be made of polyurethane or other suitable materials. • Stabilization devices enable the design of cost-effective cable protection systems.

[0063] The stabilization device functions as a reliable subsea interface to, for example, fixed offshore wind turbine foundations, but is not limited to this purpose. It can, of course, be used for other types of installations and is applicable to other offshore industries that have fixed foundations. Furthermore, the stabilization device is also usable in other areas where the dynamics of meteorological and oceanographic conditions affect flexible lines such as cables and umbilicals at the subsea interface. This includes floating structures and other suitable offshore structures.

[0064] <Bending stress management / Bending stress relaxation> The objective of the present invention is to provide a specific bending curvature for cables and cable protection systems, regardless of the properties of the seabed or changes therein, thereby extending the fatigue life of cables beyond the minimum necessary without exceeding the design limits of cables and cable protection systems.

[0065] The bending control system, equipped with a cowling unit, provides bending stress relief functionality (similar to a typical bending reinforcement device) to the cable and cable protection system. This functionality is achieved even when covering up to 180 degrees of the circumference of the cable or cable protection system. The dynamic effects of seawater particles are, in most cases, directed towards horizontal movement perpendicular to the direction of the cable and cable protection system.

[0066] Furthermore, the stabilization device is capable of providing scour protection for cables and cable protection systems, or enclosing them in tension and compression against the seabed.

[0067] The stabilization device may include a bending reinforcement structure, or, for example, a device that resists compression / extension, and may also include alternatives for two-dimensional bending control (e.g., spring-type or hydraulic pressure absorber type devices).

[0068] Furthermore, the bending rigidity of the cowl unit may be a combination of several features (for example, the rigidity of the cowl unit and the rigidity of the stays (supports / reinforcements) and absorber cylinders).

[0069] The bending stress control unit, or cowl unit, is positioned on the side of the stabilization base, or, if multiple stabilization bases exist, at the center of the multiple stabilization bases. The cowl unit is formed in a semi-conical shape to slide over the cable protection system. This semi-conical or dome-shaped structure is called a cowl.

[0070] This provides a bending management system that can be placed on a submarine cable unit. Because this system can be placed close to the landing point (where the cable, or the catenary portion of the cable protection system, makes contact with the seabed or scour protection), it does not require absolute positioning at the landing point (touchdown).

[0071] The cowl unit may have its tip set higher on a wing-like structure to maintain a smooth curvature, along with the cable protection system and cable catenary. The bending stiffness gradually increases from the tip. This structure provides the cable and cable protection system with a submarine interface that manages bending, i.e., a bending reinforcement device directed towards the stabilization position. As a result, the bending stress managed by the stabilization device is released from the cable and cable protection system.

[0072] The effect on cables and cable protection systems is that the curvature is limited to the bending moment allowed by the design of the stabilization device. Eliminating severe curvature reduces overall mobility, thus reducing local tension, slip, and compression of the cable conductor. This reduces cable wear, significantly extending the fatigue life of the cable.

[0073] The cowl is intended to contact the upper 180-degree circumference of the cable protection system and / or cable. However, the tip is equipped with a reinforced vertical wall to provide Z-axis stability in case the catenary of the cable protection system and / or cable falls below the arc of the cowl. This structure provides a wide tolerance for the landing (touchdown) of the cable and cable protection system, allowing for positional adjustments when placing the system over the cable protection system and cable.

[0074] At the rear end ("the side away from the wind turbine"), the structural rigidity should be very high and preferably solid. This allows the rigidity to gradually increase along the entire length of the cowl. The length of the bending stress management system provides the minimum curvature required for the cable's fatigue life (exceeding the design limits of the cable and cable protection system). The rigidity and length of the cowl structure are designed to provide a sufficiently low curvature to ensure the minimum fatigue life of the cable.

[0075] The bending rigidity of the cowl is preferably supported by an absorption device stage from the base. This increases the horizontal Z-axis rigidity and limits vertical (Y-axis) movement.

[0076] The rear end of the cowl may end in a solid (non-flexible) section, as described above. Preferably, this end is secured to one or more stabilizing bases. Furthermore, the stabilizing base (which may be of any shape) can be a closed structure having a flexible (elastic) front-end interface. Bending control is provided by the ability to absorb bending moments from the elastic interface, cowl structure, or a combination thereof, by providing the necessary stiffness (elasticity) to obtain a predetermined curvature limit.

[0077] Furthermore, the bending control system may be implemented as a cable protection system and / or as a gradual restriction of the free movement of the cable. This can be implemented as a semi-conical trumpet shape, or preferably as a series of bars that function based on their internal shape, structural stiffness, or a combination thereof. Preferably, this implementation is made of one or more rigid bars or similar arrangements to provide areas for tensile stress control.

[0078] <Stabilization base section> The purpose of the stabilization base is to provide an interface between the bending and tensile stress management system and the foundation on the seabed.

[0079] The purpose of the stabilizing base is to provide a structure that is located on or buried above the subsea material (scour protection and / or seabed) when it is held toward the seabed and / or the scour protection.

[0080] This device consists of at least one solid stabilizing base (open frame or block). This can be placed on one side of the bending control system, or on both sides if there are multiple stabilizing bases.

[0081] The stabilizing base preferably has a vertical opening for at least one pile element on its surface or on the side of the stabilizing base. The interface of the stabilizing base is positioned as a substantially vertical hole for at least one pile element, or as a reinforced opening inside or outside the base. Alternatively, another mechanical interface to at least one pile may play a role in transmitting the stability of the foundation to the stabilizing base.

[0082] Vertical holes or mounting points may be spaced apart to allow for initial penetration on either side of the large armorstones present in the upper layer of the scour protection. Each stabilizing base may have one or more slots to provide a variable position for driving at least one pile. Alternatively, the fixing device may be a clamp or bracket not fixed to the stabilizing base. These are attached to the pile-driving foundation to secure the stabilizing base when anchoring work is carried out on the seabed.

[0083] Furthermore, the stabilization base (of any shape) may be a closed structure with a fixed rear-end interface to the cowl unit, or the rigid portion of the cowl unit may be integrated into the base. The stabilization base may be located on both sides of the bending control system, i.e., the cowl unit, or on one side or both sides.

[0084] The stabilization base can be designed to provide the full anchoring capability with a single stabilization base. Alternatively, options for one or more stabilization bases can be provided.

[0085] Preferably, the stabilizing base is equipped with guide means, such as (but not limited to) guides for multiple pile elements. <(Tensile stress control) / (Friction or mechanical fastening)> The purpose of the friction function is to arrest the submarine cable unit in the longitudinal direction. Dynamic forces are terminated at the friction point. This prevents the dynamic forces acting on the catenary section's trajectory from being transmitted to the cable or cable protection system. Furthermore, it prevents tensile effects on the routed cable and cable protection system.

[0086] The cowl unit may have multiple feature elements to facilitate the following functions: The cowl unit, which curves towards the catenary as a high, upward-pointing arc at its tip, has low bending stiffness initially, and then increases in bending stiffness towards the anchor plate.

[0087] At the rear end, as it moves away from the cable protection system and / or the cable's catenary section, the cowl unit's bending stiffness increases, eventually becoming rigid. At this rigid "rear end," the cowl restrains the submarine cable unit.

[0088] The rigid friction areas of the cowl unit may have layers or pads to provide grip against the cables or cable protection system. Force is applied from at least one pile element and an inflatable device to press the cowl unit against the surface of the cable protection system.

[0089] Providing the cowl unit with a surface corresponding to the cable protection system and / or the outer surface of the cable (for example, providing an internal convex surface that conforms to the concave shape of the cable protection system and / or the cable, or providing a projection that fits into a groove) makes it possible to mechanically secure the cable protection system within the cowl unit. This provides a firm anchor (solid anchoring) of the cable protection system and / or the cable within the rigid portion of the cowl.

[0090] The stabilization device in operation, i.e., the cable protection system and the cowl unit installed with the cable system, preferably has a section of high-friction pads during operation. These pads are compressed onto the surface of the cable protection system during the installation of the stabilization base. The use of compression plates allows for adjustments to the cable protection system, marine organism attachment, and silt.

[0091] If the cable protection system or cable has a variable diameter outer shape, the cowl unit is made to reflect this shape. This allows the cable protection system to prevent longitudinal movement when under tension.

[0092] For cable protection systems tailored to specific purposes, positioning can be achieved by a set of cams and grooves. The rigid section of the cowl secures the cable protection system by having friction pads or structures inside to provide sufficient friction over the upper 180 degrees of the cable protection system.

[0093] The dedicated cable protection system interface has a grooved section. This grooved interface interacts with the interface structure inside the cowl unit (for example, a cam protruding into the groove secures the cable protection system, preventing longitudinal movement of the cable protection system when subjected to tension).

[0094] Foundation The purpose of a foundation is to provide a fixed horizontal position for seabed structures such as wind turbines and substations, and to maintain that position regardless of the movement or changes in the seabed.

[0095] The recommended method for the foundation is to use at least one pile element, ground screw, or similar structure. At least one pile element allows a remotely operated vehicle (ROV) to mount the base / bending management system and foundation (pile / screw, etc.) onto a tool skid and to be powered by the ROV. The tool skid can carry the stabilizing base / cowl unit and the required pile element / screw / anchor for one cable end.

[0096] The operation is preferably performed remotely, that is, a starting and penetration drive means (preferably vibro-piling, torque screw, or suction anchor pile driving) is used.

[0097] At least one pile element may be of the type of typical pile (e.g., steel or concrete, or other material having the ability to protect the seabed and / or penetrate it), ground screw (a pile-type structure that penetrates the seabed by rotation), or suction pile anchor.

[0098] Preferably, each pile element, screw, etc., has the ability to fix the stabilizing base to the seabed and to maintain its position until the end of the project. This ability includes, but is not limited to, shock absorption during installation and longitudinal and transverse compressive forces during operation.

[0099] During the installation of at least one pile element, hammering, vibration, screwing, suction, or a combination thereof may be used. At least one pile element can have any shape or profile, such as an H-beam, X-beam, sheet pile, wooden pile, or pipe (driven in with a hammer or vibrated). For example, at least one pile element may be a ground screw, suction pile, or cone. At least one pile may also be anchored to solid rock.

[0100] At least one pile element may be equipped with an expansion device, such as an expandable (compressible) coupling. Compression is achieved by the force of at least one pile as the pile is driven into the seabed.

[0101] Preferably, the expansion device is compressed before installation and attached to a pile or the like. The arrangement for retaining this compression is set up so that it deteriorates or is released shortly after installation, thereby releasing the compressive force to the base.

[0102] Alternative foundation Furthermore, alternative foundation devices are provided for submarine cable units (cables, or cables equipped with cable protection systems). These alternative foundation devices mitigate seabed dropping without altering the catenary shape of the installed submarine cable units. Seabed dropping can occur in the area beneath or around submarine cable units due to localized seabed erosion or scouring.

[0103] This alternative foundation device has the advantage of allowing installation in locations where seabed erosion has allowed the cable unit to have free span between the landing site (already installed location) and the original pre-erosion seabed level or the Scour Formation level. Therefore, this alternative foundation device provides the cable and cable protection system (CPS) above seabed level by allowing the seabed cable unit to be installed suspended above seabed level. Thus, it provides an artificial landing base without altering the catenary shape (and therefore without changing the cable tension).

[0104] This foundation device may be used when erosion due to localized water flow conditions is expected, or to prevent excessive bending of submarine cable units when laying them over depressions in the seabed.

[0105] Therefore, a foundation device for a submarine cable unit is provided, which consists of a submarine cable with a cable protection system, or a submarine cable alone. The foundation device comprises the following:

[0106] • Pile elements adapted for driving into the seabed or scour-resistant layer, • Mounting unit attached to the top of the pile element, • A support element attached to the mounting unit, which is adapted to support the submarine cable unit when the foundation device is installed. The mounting unit includes a locking element attached to the mounting unit, which is adapted to lock at least the submarine cable unit to the foundation unit.

[0107] Furthermore, a bending reinforcement device unit is provided which includes a bending reinforcement. The bending reinforcement is attached to the submarine cable unit and is adapted to control the bending of the submarine cable unit. The bending reinforcement device unit further includes at least one mounting element which is attached to the bending reinforcement and extends outward from the outer surface of the bending reinforcement. This mounting element is adapted to be positioned between a support element and a locking element.

[0108] The bending reinforcement device unit preferably comprises at least two mounting elements positioned on one side of the bending reinforcement. These mounting elements are spaced apart in the longitudinal direction of the bending reinforcement. Preferably, the distance between these two mounting elements is adjusted to the size of the locking element, i.e., the conical shape of the locking element.

[0109] The support elements and / or locking elements are preferably adjustablely mounted to the mounting unit. The mounting unit is threaded, and the support elements and / or locking elements are equipped with corresponding threads. This allows the position of the support elements and / or locking elements to be adjusted on the mounting unit.

[0110] The support element may have a conical contact surface on which the submarine cable unit rests. The conical shape of the support element is adjusted to provide optimal support for the submarine cable unit, taking into account the inclination position of the pile element relative to the seabed or scour-resistant layer after installation.

[0111] The bending stiffener body of the bending stiffener unit is preferably semi-domed. This means that when the bending stiffener unit is attached to the submarine cable unit, the bending stiffener body substantially covers the upper half of the outer surface of the submarine cable unit.

[0112] The bending reinforcement device unit preferably includes wedge-shaped mounting elements, each of which has a contact surface with the locking element, adjusted to contact the locking element. The locking element preferably has a locking surface that faces a mounting element or group of mounting elements of a bend reinforcement unit, which has a conical shape.

[0113] Preferably, the locking surface of the locking element comes into contact with the contact surface of the mounting element of the bend reinforcement unit after the foundation device has been installed. Preferably, the bend reinforcement unit further comprises four mounting elements, two of which are positioned on both sides of the bend reinforcement body and four which are positioned at intervals along the longitudinal direction of the bend reinforcement body.

[0114] Preferably, the distance between the two pairs of mounting elements on either side of the bending reinforcement is adapted to the size of the locking element, i.e., to the conical shape of the locking element positioned or attached to the mounting unit of the two pile elements.

[0115] A method for providing a foundation for a submarine cable unit is also provided. The submarine cable unit comprises a submarine cable with a cable protection system, or a submarine cable alone. The method comprises the following steps.

[0116] A step of providing two base devices according to any of the above embodiments, A step of partially positioning the pile elements of the foundation device on the seabed and / or scour prevention layer so that they are inclined with respect to the seabed or scour prevention layer, and so that the support elements already positioned on the mounting unit are in a position to support the seabed cable unit, If the submarine cable unit has not yet been installed, the process involves installing the submarine cable unit so that it is supported by the support elements (support elements, support members) of the foundation device. The method includes the step of arranging a locking member on the mounting unit of each pile element so that the submarine cable unit is fixed in a predetermined position on the support element.

[0117] Furthermore, this method includes a step of placing a bending reinforcement unit on the submarine cable unit before placing the locking element on the mounting unit, so that the mounting element is adjacent to the mounting unit of the pile element.

[0118] The locking elements are preferably positioned on the mounting unit of each pile element. The locking elements contact the mounting element of the bending reinforcement unit, thereby fixing the bending reinforcement unit and the submarine cable unit in place.

[0119] The two pile elements should preferably be positioned so that the support elements support the submarine cable unit after installation. The position of the support elements is adjustable to the desired position on the mounting section to support the submarine cable unit.

[0120] It is preferable that the bending reinforcement body be positioned on top of the submarine cable unit such that the mounting elements of the bending reinforcement unit are adjacent to the mounting units on the pile elements, after the two pile elements have been positioned in their predetermined locations and the support elements have supported the submarine cable.

[0121] Multiple pile elements are positioned at an inclination relative to the seabed or scour-resistant layer. This gives the pile elements a scissor-like shape. The arrangement of these two foundation devices provides stable support for the submarine cable unit.

[0122] Compression onto the seabed. The purpose of this feature is to maintain vertical seabed contact between the base and the bending management system in the event of a decrease in the level of the scour prevention layer or seabed.

[0123] To retain the cable protection system within the cowling, the stabilization device must be compressed against the seabed or scour-prevention structure below. To prepare for potential sinking of the scour-prevention structure or sinking and scouring of the mobile seabed, the vertical foundation of the base is connected to at least one pile element, rod, or column via a pre-tensioned inflator. This inflator pushes the stabilization base downward towards the seabed or scour-prevention structure, ensuring that the stabilization base remains at seabed level or scour-prevention level even if the seabed level or scour-prevention level drops. The inflator may consist of a compression spring mechanism (such as a spring element) or other devices capable of simultaneously inflating in length while pushing the stabilization base downward towards the seabed or scour-prevention layer. The inflation length should preferably be designed to be greater than or equal to the maximum possible drop in the seabed or scour-prevention layer water level.

[0124] The inflation device is held in a pre-compressed state by a disassemblable clip or rope that is released after a predetermined period of time has elapsed since installation. <Allowance for wind turbine foundation settlement (sinking into the seabed).> The purpose of this function is to maintain the cable protection system and cable curvature without compression, even if the wind turbine foundation sinks to the seabed after the cable has been laid.

[0125] The curvature of the cable protection system is predetermined, and the base is positioned on a catenary within the contact points of the cable protection system. Therefore, a large radius of curvature can be maintained while absorbing the reduction in opening height. At the same time, it is ensured that the cable path distance (route distance) within the cable protection system and the MP (monopile) foundation is not shortened. This prevents compression of the internal cable design (a factor that increases cable fatigue).

[0126] Installation features. The purpose of these features is to minimize the impact on critical stages of the offshore construction campaign, mitigate risks, and stabilize existing cables and cable protection systems.

[0127] Since the stabilization device is designed to be installed on top of the cable or cable protection system, the cable or cable protection system laid on the seabed is covered by the structure. The versatility of seabed anchors allows for a stable foundation for the stabilization base (stabilization base) by selecting a single or multiple pile elements.

[0128] Both the stabilization device and the pile element are transportable by a remotely operated vehicle (ROV) and are equipped with a tool skid that allows the stabilization device and pile element to be docked before the ROV is deployed. At the underwater installation site, the stabilization device is released, for example, using a manipulator arm, and placed on a cable protection system. Then, the tool skid raises at least one pile element upright, and once its bottom end is within the interface of the stabilization base, the ROV's power unit (hydraulic unit for hydraulically driven ROVs, electric unit for electrically driven ROVs, etc.) drives the pile into the ground.

[0129] This installation method eliminates the need for lifting heavy objects or for surface vessels to approach offshore seabed structures. Furthermore, stabilization can be performed simultaneously with cable pull-in, allowing it to be integrated into the pull-in procedure without disrupting the critical path. For example, it can be carried out within the time frame between the time the cable protection system is secured to the opening or bellmouth and the establishment of a temporary cable suspension (hang-off) state. Typically, a 30-60 minute slot for the remotely operated vehicle (ROV) to monitor the seafloor interface is sufficient, and using this slot for foundation installation does not affect cable laying efficiency. This means that stabilization of the cable protection system and / or the cable can be provided within the cable pull-in process. This can be achieved by utilizing an idle observer ROV during the typical 30-60 minute waiting time between the latching / interlocking of the cable protection system and the temporary cable suspension within the tower. In this method, the stabilization device is outside the critical path of cable laying, thus achieving immediate stabilization during pull-in without delaying cable laying.

[0130] The installation does not affect the cables within the cable protection system. For example, because stabilization can be performed after locking in the cable protection system, the cables can still be routed to the switchgear (switching device) even after stabilization.

[0131] Furthermore, installation from a CLV (cable laying vessel) using a remotely operated underwater vehicle (ROV) is also possible. <Materials. > Cost is a major barrier to offshore wind power generation. This invention enables the use of "low-grade" commercially available industrial materials such as glass fiber reinforced epoxy resin and carbon steel. It can provide designs that use steel in combination with anodes and designs that allow for water absorption to meet design criteria that include end-of-life requirements. Therefore, the use of high-cost steels, composite materials, polymers, and other special materials can be avoided.

[0132] By using general-purpose industrial materials that are not specialized for cable protection or other niche markets, not only are material costs reduced, but industrial production becomes possible in most regions. This reduces transportation costs and CO2 emissions, and creates opportunities for localized supply chains within the areas where wind power plants are installed.

[0133] Type approval. This invention facilitates arbitrary type approval for a wide range of cable designs (within a broad tolerance range regarding the height of the base interface, the catenary length, and the location of the invention). Such type approval is possible because stabilization through a predetermined bending response eliminates the need to handle curvature and stress at the catenary landing point from the cable protection system. This allows for the incorporation of engineer capacity to prepare for worst-case scenarios, thereby reducing the bending moments and tensions acting on and managed by the cable protection system. This capacity can be designed to meet cable fatigue life requirements even in the most demanding cable designs.

[0134] This enables the optimization of cable boundary conditions considered during the cable design phase. Since it eliminates the need to consider extreme curvatures and tension parameters in cable design, it becomes possible to determine design parameters that optimize the cable's primary function (power and signal transmission) and cost.

[0135] Regarding installation, this stabilization device offers the following advantages: • The work on the foundation ship will not be in close proximity. • Heavy lifting of ballast materials is unnecessary.

[0136] • Immediate stabilization is possible (integrated into cable laying work). • The work is done quickly (completed in 15-25 minutes). • Can be implemented on the seabed or through scour-preventing structures.

[0137] The installation of operational cable protection systems and stabilization devices on cable systems can be carried out from any support vessel with remotely operated vehicle (ROV) capabilities, which offers the following advantages:

[0138] 1. Work on the foundation ship does not require close proximity. 2. Lifting heavy ballast materials is unnecessary. 3. No personnel are required to be stationed inside the tower.

[0139] 4. The work is done quickly (completed in 15-25 minutes). Therefore, the present invention offers numerous advantages. • Eliminate risks associated with seabed topography and changes, while also providing cable protection systems and / or cable stabilization.

[0140] ○ By stabilizing seafloor protection systems and / or cables, eliminate the impacts, risks, and uncertainties of seafloor topography, including (but not limited to) seafloor movement and fluctuations.

[0141] • By eliminating the risk of reduced cable fatigue life (risk of cable failure during operation), the bending management system provides stabilization. ○ Provides a cable protection system and / or a bending control system that frees cables from excessive curvature. This reduces the effects of localized tension, slippage, and compression on cables, and improves cable fatigue life.

[0142] • Provides stabilization functions integrated into cable laying operations. ○ The stabilization device enables immediate stabilization integrated into cable laying operations without affecting the critical path.

[0143] • Stabilization is achieved without using ballast materials (rocks, rock filter bags, mattresses, etc.). ○ The stabilization device functions without requiring ballast material.

[0144] • Achieves stabilization without the need for crane or lifting operations. ○ Eliminate the need for lifting and crane operations. • Stabilization is achieved without requiring access to wind turbines or substations.

[0145] ○ Eliminate the need for surface vessel work near offshore foundations. • The tolerance for positioning is wide. ○The complex and often impossible positional accuracy required becomes unnecessary.

[0146] • To detect settlement of the MP (monopile) foundation after installation. ○The cable protection system and / or cable compression that causes the wind turbine monopile to sink (drop) is eliminated.

[0147] In short, this system provides a solution to conditions that threaten cable protection systems and / or cable fatigue life. It eliminates uncertainty at the seabed interface and eliminates the need for ballast material. This results in a stable bending control system that absorbs changes in the seabed and variations during installation.

[0148] Not only does this eliminate the need for ballast material, transportation, and installation, but it also eliminates the risks and uncertainties to cables and / or cable protection systems associated with stabilization by ballast material.

[0149] Non-limiting embodiments of the present invention will be described with reference to the attached drawings. [Brief explanation of the drawing]

[0150] [Figure 1] Side view of the stabilization device and the seabed system. [Figure 2] Perspective view of the stabilization device and the seabed system. [Figure 3] This shows a stabilization device. [Figure 4] This diagram shows a stabilization device comprising a pile element and its expansion device. [Figure 5] The diagram shows pile elements driven into the seabed and / or scour-resistant layer, along with stabilizing devices. [Figure 6] This shows the cowl unit of a stabilization device equipped with first and second clamping devices. [Figure 7] This shows a stabilization device without pile elements. [Figure 8] Figure 7 shows the stabilization device as viewed from the front. [Figure 9] This shows a stabilization device comprising two stabilization bases already positioned on both sides of the cowl unit, namely a first stabilization base and a second stabilization device. [Figure 10] The stabilization device is shown, which includes a separate loose clamping (loose, movable) element having at least one hole for a pile element. [Figure 11] Figure 10 shows a stabilization device equipped with separated loosening clamp elements, viewed from below. [Figure 12] The stabilization device is shown, which has separate loose clamp elements of different designs and similarly has holes for at least one pile element. [Figure 13] This shows a stabilization device equipped with a dynamic absorber (dynamic absorber, dynamic absorption device). [Figure 14] The diagram shows a stabilization device comprising a cowl unit and two dynamic absorbers attached to a first stabilization base and a second stabilization base, respectively. [Figure 15] The image shows a motion-retaining element provided on the cowl unit of the stabilization device, which is adapted to engage with a submarine cable, or, if a cable protection system is provided on the submarine cable, to engage with a cable protection system. [Figure 16] Figure 15 shows how the motion-retaining element is installed on the cowl unit, viewed from a slightly different angle. [Figure 17]This shows a motion-retaining element in the shape of a slot / cavity / groove / recess, provided in the cowl unit and adapted to engage with a cable protection system and / or a portion of a cable passing through the cowl unit. [Figure 18] This shows a centrally positioned stabilization device above the cable protection system and / or the cable's landing (touchdown) point. [Figure 19] The stabilization devices already in place are shown outside the cable protection system and / or the landing point of the cable system. [Figure 20] The central position of the stabilization device is shown in two locations in the diagram: outside the landing point of the cable protection system and / or cable system on the left side of the diagram, and inside the landing point of the cable protection system and / or cable system on the right side of the diagram. [Figure 21] This shows the stabilization device already installed on the scour prevention structure. [Figure 22] This shows a stabilization base section, with guide elements provided in each hole for the pile element. [Figure 23] The figure shows the expansion device of the stabilization device, with the center representing the compressed state and the right side representing the relaxed state. [Figure 24] This shows a stabilization device already installed on the scouring seabed. [Figure 25] This diagram shows two positions of the stabilization device in the event of a seabed drop. The upper diagram shows the installation height relative to the seabed level at the time of installation, while the lower diagram shows the state after the seabed has dropped. [Figure 26] This shows the stabilization device used during installation, before the seabed level dropped. [Figure 27] This shows the stabilization device after the seabed level has been lowered. [Figure 28] Figures 1 to 26 show a bending control system that can be used as a replacement for the cowl unit. [Figure 29] Figure 28 shows the bending control system, viewed from the side. [Figure 30]This describes a stabilization system equipped with multiple clamping devices that form a semi-trumpet shape, that is, a shape in which the length gradually increases from one end to the other. [Figure 31] Figure 30 shows a stabilization system equipped with multiple clamping devices, viewed from above. [Figure 32] This shows a restraining device that reinforces longitudinal restraint by reliably deforming the outer surface of the cable protection system. [Figure 33] Figure 32 shows the stabilization device viewed from below. [Figure 34] This shows a submarine cable equipped with a cable protection system, already installed on the seabed or on a seabed erosion prevention layer. [Figure 35] Figure 34 shows a cable equipped with a cable protection system, illustrating a situation where, for example, the seabed or scour-resistant layer has been lowered by a distance D due to erosion, causing the cable and cable protection system to be suspended above the seabed or scour-resistant layer. [Figure 36] The diagram shows a submarine cable unit already positioned on the seabed and / or scour-resistant layer, along with two foundation devices. These are inclined relative to the seabed or scour-resistant layer and form a scissor shape, supporting the submarine cable unit suspended above the seabed or scour-resistant layer. [Figure 37] The image shows the submarine cable unit being supported by two support elements already positioned on two pile elements of the foundation, and a bending reinforcement unit being lowered onto the top of the submarine cable unit. [Figure 38] Figure 37 is a side view showing the same process, namely, the bending reinforcement unit being lowered onto the top of the submarine cable unit. [Figure 39] This shows a state in which a bending reinforcement unit is installed on a submarine cable unit, and both units are fixed in place by locking members already positioned on the pile element. [Figure 40a] A front view showing the same object as in Figure 39. [Figure 40b]A side view showing the same object as in Figure 39. [Modes for carrying out the invention]

[0151] First, it should be noted that the submarine cable unit 18 of the present invention may be a cable alone, or a cable equipped with a cable protection system 20. Figures 1 and 2 show a stabilizing device 22 and a subsea system 10 according to the present invention. This subsea system 10 comprises a monopile 12. A specific application of the stabilizing device 22 according to the present invention is a known cable protection system 20 (referred to as "J-tubeless") for monopile 12 foundations without J-tube configuration in the offshore wind power industry. Here, at a cable entry or aperture hole 13 provided in the monopile 12, the cable protection system 20 of the subsea cable unit 18 is mechanically locked into the aperture hole 13 by a mechanical connector / latch / interface unit 14 of the cable protection system 20.

[0152] The stabilization device 22 is installed on the seabed 17 by one or more pile elements 54. These pile elements 54 penetrate the upper layer, the highly mobile surface layer, and, if applicable, the scour protection layer 15.

[0153] While this stabilization device 22 is shown as being applicable to a submarine cable unit for a monopile foundation (12), it provides a similar basis for other foundation structures and interfaces. For example (but not limited to), this applies to J-type bellmouth interfaces for wind turbines. It is also applicable to other submarine interfaces where underwater lines (cables, flexible tubes, umbilicals, etc.) benefit from a controlled bending management system.

[0154] Figure 3 shows details of the stabilization device 22 according to the present invention. The stabilization device 22 is preferably designed to fit on top of a submarine cable unit 18 located on top of a cable protection system 20. Preferably, the stabilization device 22 is fixed in a position relative to a wind turbine generator or substation foundation using pile elements 54. The upper part 56 of the pile elements 54 is provided with a handling interface 57 (see Figure 23) for handling and uprighting, for example, by a remotely operated vehicle (ROV). One or more pile elements 54 provide horizontal stability to the stabilization device 22. The pile elements 54 also provide vertical stability to the stabilization device 22 with respect to the seabed 17 and / or scour protection layer 15. Preferably, the upper part 56 of the pile elements 54 of the stabilization device 22 may be provided with an expansion device 59 with expansion capability. This applies a vertical force to at least one stabilization base section (24, 25) of the stabilization device 22. Therefore, even if the level of the seabed 17 is lowered due to erosion, for example, the stabilization device 22 is guaranteed to maintain a compressed state toward the seabed 17.

[0155] The stabilization device 22 provides a bending stress relief function to the submarine cable unit 18. This function is preferably provided as a cowl unit 45, which is a dome-shaped structure. The cowl unit 45 covers up to 180 degrees, preferably beyond 180 degrees, of the upper circumference of the submarine cable unit 18. To provide a bending control system, the cowl unit 45 may be assisted by a flexible interface, which preferably has the form of a first clamping device 27 attached to at least one stabilization base section (24, 25). In the direction of the submarine cable unit 18 and / or the cable catenary, i.e., in the direction of the other end of at least one stabilization base section (24, 25) (i.e., the end away from the submarine cable unit catenary), a more rigid interface (preferably in the form of a second clamping device 28) is provided. The second clamping device 28 has a higher bending moment than the first clamping device 27.

[0156] As shown in Figure 4, the stabilization device 22 is positioned to be mounted on top of the submarine cable unit 18, i.e., on top of the cable protection system 20 and / or the cable. At least one stabilization base section (24, 25) of the stabilization device 22 is positioned on one side of the submarine cable unit 18, or on both sides as shown in Figure 4. Dual-sided stabilization base sections (24, 25), i.e., consisting of a first stabilization base section 24 and a second stabilization base section 25 positioned on both sides of the submarine cable unit 18 passing through the stabilization device 22, are adapted for improved stability on uneven surfaces (not limited to, for example, large-diameter armored rock (such as D90 rock with a diameter of 900 mm)). The first and second stabilization base sections 24, 25 are provided with at least one mounting device (e.g., a through-mounting device). This makes it possible to fix a submarine cable unit 18, which includes, but is not limited to, large-diameter armored rocks such as D90 rocks with a diameter of 900 mm, to the stabilization device 22. The first and second stabilization base sections 24 and 25 are provided with at least one mounting device (e.g., through-hole 42) for a pile element 54. In Figure 4, the first and second stabilization base sections 24 and 25 are each provided with three through-holes 42, through which a pile element 54 can be passed. In this example, the first and second stabilization base sections 24 and 25 are each stabilized by one pile element 54, but it is also possible to provide a pile element 54 in each through-hole 42. The upper part 56 of the pile element 54 is long enough to accommodate an expansion device 59, as shown in the figure. This expansion device 59 is compressed when the pile element 54 is driven into the ground. Alternatively, it is preferable to provide an expansion device 59 with a pre-set compression length before installing the stabilization device 22.

[0157] As shown in Figure 5, the stabilization device 22 is positioned on the seabed without a scour prevention layer 15, and the pile element 54 penetrates the seabed 17. The penetration length 55 of the pile element 54 maintains its horizontal position relative to the monopile 12 of the wind turbine or substation foundation, while the expansion device 59 fixes the vertical position of at least one stabilization base section (24, 25). This holds the cowl unit 45 and the first and second clamping devices 27, 28 relative to the submarine cable unit 18.

[0158] As shown in Figure 6, the cowl unit 45 of the bending control system is arranged in a dome shape. A flexible tip 46 is preferably provided along the longitudinal direction of the cowl unit 45 to allow the dome shape of the cowl unit 45 to follow the catenary trajectory of the submarine cable unit 18. When the dome center 47 and horizontal section 48 of the cowl unit 45 are pushed down around the submarine cable unit 18, the less rigid tip 46 of the cowl unit 45 ensures tapered bending stress relief that (a) follows the catenary shape of the submarine cable unit 18 and (b) minimizes stress concentration at the dome origin. The side sections 49 of the dome are configured to hang down like a curtain, allowing the submarine cable unit 18 to be guided even if it is not compressed towards the dome roof of the cowl unit 45.

[0159] The rigidity of the cowl unit 45 of the bending control system is configured to increase along the length of the dome-shaped cowl unit 45, as with conventional bending stress relief, since it has a soft tip 46. At the end opposite to the soft raised tip (46), the bending stress relief is preferably terminated by a rigid end section. This rigid end may be an integral part of at least one stabilizing base section (24, 25) (not shown in Figure 6), or it may be connected to at least one stabilizing base section (24, 25) via a rigid support frame in the form of a second clamping device 28, as shown in Figure 6.

[0160] This configuration is similar to the rigid end section of conventional bending stress relief devices / end reinforcements. Here, the base is a rigid metal flange structure, and the rigidity of the bending stress relief device / end reinforcement is designed to provide a predetermined curvature to flexible bodies such as flexible flow lines, umbilicals, cables, and lines, depending on the tensile force and angle (usually shown in polar coordinates). To give flexible flow lines, umbilicals, cables, or lines sufficient fatigue life, the bending control system must satisfy its design limits and fatigue curvature-tension combination.

[0161] This is made possible by a dome-shaped cowl unit 45 that maintains sufficiently enhanced rigidity along its entire length. Alternatively, the dome can be supported by a flexible support or damping device positioned between the tip and the rigid end (shown as the dome center 47 in Figure 6). This allows the integrated management system to ensure sufficiently low curvature of the flexible flow line, umbilical, cable, or line, thereby providing a sufficient fatigue life.

[0162] Due to the nature of the stabilization device 22, free movement is limited to the upper 180 degrees only. The seabed 17 (or scour prevention structure 15) and the trajectory of the submarine cable unit 18 from the foundation interface restrict the movement of the submarine cable unit 18 to the lateral (all directions) and upward (lifting) directions. Therefore, the dome-shaped cowl unit 45 must control the dynamic movement of the submarine cable unit 18 to only these directions.

[0163] Figures 7 and 8 show the stabilizing surface 26 of at least one stabilizing base portion (24, 25) with a through hole 42 for the pile element 54 already formed and positioned in the open structure. One or more guide elements (members) 43 (not shown in Figures 6 and 7, see Figure 22) can be provided in the through hole 42 to facilitate the insertion of the pile element 54 into the through hole 42.

[0164] The horizontal section 48 of the dome-shaped cowl unit 45 is designed to fix the submarine cable unit 18 toward the seabed 17 (or scour prevention device 15), as will be described later. Alternatively, at least one stabilizing base portion (24, 25) may be provided on only one side of the cowl unit 45. The number of through holes 42 for the pile element 54 can be one or more, as described above.

[0165] Alternatively, stabilizing base sections (24, 25) can be placed on both sides of the cowl unit 45. Similarly, the number of through holes 42 for the pile element 54 in each stabilizing base section (24, 25) can be one or more.

[0166] As an alternative, two stabilizing bases (24, 25) can be provided on both sides of the cowl unit 45, as shown in Figure 9. As shown in Figures 10 and 11, the stabilizing base sections (24, 25) can also be designed without providing designated through-holes 42 for the pile elements 54. Instead, one or more loosening clamp elements (39) can be used, each having at least one through-hole 42 for a pile element 54.

[0167] The clamp element 39 is provided with a groove 40 for holding the opening of at least one stabilizing base portion (24, 25). Alternatively, a projection of at least one stabilizing base portion (24, 25) may be fitted into the groove 40, recess, or slot, or vice versa, to be combined with a groove or slot of at least one stabilizing base portion (24, 25).

[0168] Alternatively, as shown in Figure 12, at least one stabilizing base portion (24, 25) can be fixed by a clip-type clamping element 39 having at least one through hole 42 for the pile element 54.

[0169] As shown in Figures 13 and 14, the cowl unit 45 of the bending control system can be supported by two absorbers 30 as shown in Figure 14, or by one absorber 30 as shown in Figure 13, instead of the flexible first clamping device 27. This depends on whether the stabilizing device 22 has two or one stabilizing base section (24, 25), thereby allowing the desired curvature to be obtained. The absorber 30 can be fixed at one end to a first anchor section 31 on a single stabilizing base section (24, 25) as shown in Figure 13, or to both stabilizing base sections (24, 25) as shown in Figure 14, and at the other end to a second anchor section 32 on the cowl unit 45.

[0170] In conventional bending stress relief / end reinforcement materials, the flexible portion is mechanically terminated to a fixing device, giving the end portion of the bending stress relief / end reinforcement material rigidity. In contrast, when this bending management system replicates a bending stress relief / end reinforcement material, it is preferable that the stabilization device 22 is adapted to restrain (restrain) the submarine cable unit 18 in its longitudinal direction. This ensures that the dynamic motion in the catenary of the submarine cable unit does not force a change in the position of the submarine cable unit 18. This function also ensures that the tension acting on the submarine cable unit 18 is not transmitted to the submarine cable unit 18 located on the opposite side of the stabilization device 22.

[0171] The longitudinal restraint of the submarine cable unit 18 is achieved by a motion-restraining element 51, which takes the form of a high-friction layer provided, for example, within the horizontal section 48 of a dome-shaped cowl unit 45, as shown in Figures 15 and 16. The entire ceiling of the cowl unit 45 can be fitted with a high-friction material or substance (not limited to, for example, natural rubber or neoprene (preferably EDS-6 hardness grades 67, 73, and 78)).

[0172] As shown in Figures 15 and 16, friction can also be provided by motion arresting elements (motion stopping elements, motion restraining members) 51, which are positioned inside the dome-shaped ceiling of the cowl unit 45 in the form of panels or friction pads. Thus, the dome-shaped cowl unit 45 is compressed against the submarine cable unit 18 while it is being stabilized on the seabed 17 or the scour prevention layer 15. Consequently, the submarine cable unit 18 is pressed against the friction pads after it falls onto the cable protection system 20 due to the vertical foundation force acting on at least one stabilizing base section (24, 25). This increases friction, preventing the submarine cable unit 18 from slipping and preventing the transmission of tension from the stabilizing device 22.

[0173] Alternatively, as shown in Figure 17, the submarine cable unit 18 is held inside a dome-shaped cowl unit 45, preferably within the horizontal portion 48 of the cowl unit 45, by a motion-retaining element 51 having a slot / cavity / groove / recess shape. This motion-retaining element 51 is configured to fit into a specific length section of the submarine cable unit 18.

[0174] As shown in Figure 18, the stabilization device 22 can be positioned near or above the landing point (touchdown point, grounding point) 34 of the submarine cable unit 18. In this figure, the stabilization device 22 is positioned above the center of the landing point 34 of the submarine cable unit 18. This positioning requires high installation precision. To ensure flexibility in the installation position of the submarine cable unit 18 relative to the landing point 34, the flexibility of the bending control system is designed to allow for a wide tolerance.

[0175] In Figure 19, the center 35 of the stabilization device 22 is positioned outside the landing point 34 of the submarine cable unit 18. The capacity (tolerance) of the bending control system can be designed to accommodate the required maximum horizontal outward position.

[0176] Alternatively, the center 35 of the stabilization device 22 can be positioned inside the landing point 34 of the submarine cable unit 18. The capacity of the bending control system can be designed to accommodate the required minimum horizontal inward position.

[0177] As shown in Figure 20, this provides a large degree of freedom in the horizontal positioning of the stabilization device 22 on the submarine cable unit 18. This is shown by two alternative positions of the center 35 of the stabilization device 22. This horizontal degree of freedom also allows for variability in the cable protection system and the cable direction (orientation).

[0178] As shown in Figure 21, in the open-type option for the stabilization base, it is possible to place the box-shaped first stabilization base 24 and second stabilization base 25 on top of the submarine cable unit 18 on both sides of the cowl unit 45 of the bending management system.

[0179] One or more pile elements 54 extend from the upper parts of the first and second stabilizing base sections 24 and 25, penetrating deeply to a stable seabed (indicated by reference no. 17). For example, they reach the seabed by passing through the scour-resistant layer 15.

[0180] As shown in Figure 22, the through holes 42 for the pile elements 54 present in at least one stabilizing base portion (24, 25) may be provided with guide elements 43 to help the pile elements 54 enter their respective through holes 42.

[0181] The compression system of the stabilization device 22 is equipped with an expansion device 59, and as shown in Figure 23, when driving in a foundation type (i.e., pile elements 54 or screws, etc.), the expansion device 59 changes from a relaxed state 61 to a compressed state 60, and its length can be reduced. Alternatively, the expansion device 59 may have the ability to expand toward an uncompressed state when applied in a compressed state.

[0182] If the seabed 17 shifts or the scour-prevention layer 15 sinks further into the seabed 17, the compressed installation length of the inflator 59 is made capable of expanding from the compressed length of the inflator toward its full length. This expanded length provides the stabilization device with vertical drop capability to follow the fall of the seabed 17 or the scour-prevention layer 15.

[0183] As shown in Figure 24, the compressed expansion device 59 releases its expansion as force downward toward at least one stabilizing base section (24, 25) and upward toward the upper part 56 of the pile element 54. This figure shows that the stabilizing device 22 is installed on the seabed 17 without a scour protection layer 15, and that a scour pit / scour hole 16 is occurring near the monopile 12.

[0184] Figure 25 shows that the stabilization device 22 is installed from its installation level 36 at seabed level to the first catenary 52 of the submarine cable unit 18, along with the compressed expansion device 59. As the seabed level decreases, the stabilization device 22 follows down to the lower level of the stabilization device 22. At this time, the expansion device 59 extends from a compressed state 60 to a further relaxed state 61 and changes to an expanded length. Thus, at least one stabilization base section (24, 25) moves from the installation level 36 of the stabilization device 22 to a new level 37 at the newly lowered seabed height. Thus, the submarine cable unit 18 is forced to deform into a new second catenary shape (53).

[0185] This causes the natural catenary shape of the submarine cable unit 18's touchdown point 34 to shift, but the bending control system's capabilities continue to control it. Therefore, even if the tension at the second catenary 53 of the submarine cable unit 18 increases, its control is maintained.

[0186] Figure 26 shows the seabed 17 at the time of installation of the stabilization device 22 (the state and location of the seabed at the time of installation of the stabilization device 22). At least one stabilization base (24, 25) is placed on a submarine cable unit 18 having a first catenary shape (52) and is fixed to the seabed by a pile element 54, and the inflator 59 is in a compressed state 60.

[0187] As shown in Figure 27, when the height of the seabed 17 and / or the scour prevention layer 15 decreases, the upper part 56 and the underwater lower part 55 of the pile element 54 remain unchanged. Therefore, as the seabed 17 sinks, at least one stabilizing base section (24, 25) follows the level of the seabed 17 by the expansion of the compressed expansion device 59. Thus, the height of the upper part 56 of the pile element 54 remains similarly elevated above the stabilizing base sections (24, 25) as the level of the seabed 17 sinks.

[0188] The expansion device 59 may preferably consist of a compression spring (as shown above and in the figures) or may consist of any expandable material that can be installed or compressed in its retracted form. In this way, mechanical limitations can be eliminated after installation, for example, by degradation in water after a predetermined period of time or by the expansion of the substrate by immersion in seawater.

[0189] As shown in Figures 28 and 29, the bending control system of the stabilization device 22 can be configured as a bending reinforcement device of a known bending stress relaxation type, for example, based on the American Petroleum Institute API_17. The bending stress relaxation base 68 is fixed to or integrated with the stabilization base 70. The bending reinforcement portion 69 of the bending control system gradually increases the bending stiffness from the tip, where the bending stiffness is lowest, to the solid base where the bending stiffness increases.

[0190] The bending stress relief device can be pre-installed on the cable protection system before pull-in. Alternatively, a preferred method uses the bending stress relief base portion 68 and bending reinforcement portion 69 of the open slot, thereby allowing the stabilization device 22 to be placed on top of the submarine cable unit 18. This method not only provides operational advantages by separating the stabilization device 22 from critical routes and the cable highway of the cable landing station CLS during installation, but also enables stabilization for already installed submarine cable units 18.

[0191] As shown in Figures 30-31, the bending control system may be configured as a gradual restriction on the free movement of the submarine cable unit 18. This can be configured as a trumpet-shaped semicone 72, preferably as a series of bars 73 based on its internal shape, structural rigidity, or a combination thereof. Preferably, it can be configured as one or more rigid bars 73 or a similar arrangement to provide areas for tensile stress control.

[0192] The longitudinal friction lip provides an upward force to the cable protection system 20, causing a slight deformation on both sides of the cable protection system 20 toward the friction pad / layer, thereby firmly (securely) securing it to the slippery surface of the cable protection system 20.

[0193] As shown in Figure 32, the stabilization device 22 may include a deformation device 64 that actively deforms the outer surface of the cable protection system 20 of the submarine cable unit 18. This strengthens longitudinal fixing and can also be used in combination with other motion-retaining elements 51 such as the friction pads / layers mentioned above.

[0194] Lateral stays 65 (for example, three on each side, although there may be one or more lateral stays 65) positioned laterally to the longitudinal direction of the cowl unit 45 are pressed down into the first and second stabilization base sections 24, 25 by the pile elements 54 and their expansion devices 59, with one end firmly attached to the cowl unit 45 at their respective mounting points 67. The other end of the lateral stays 65 is connected to a compression area 66 or pad area positioned on the first and second stabilization base sections 24, 25. When the lateral stays 65 are not pressed down, the compression area 66 is maintained in a substantially horizontal position, thereby allowing it to fit to the cable protection system 20 of the submarine cable unit 18.

[0195] As the pile element 54 applies pressure to the lateral stay 65, the lateral stay 65 applies pressure to the first and second stabilizing base portions 24 and 25, causing the other end of the lateral stay 65 to be pressed against the surface of the cable protection system 20 of the submarine cable unit 18 (as shown in Figure 33). This provides a firm grip on the outer surface of the cable protection system 20, thereby preventing movement of the submarine cable unit 18.

[0196] As shown in Figures 34 to 40, an alternative foundation device (74) for the submarine cable unit 18 is provided. This alternative foundation device (74) can accommodate either the cable alone or the cable with a cable protection system, and can mitigate the fall of the seabed 17 and / or the scour protection layer 15 without altering the catenary shape of the installed submarine cable unit 18. The fall of the seabed 17 and / or the scour protection layer 15 can occur in the area below or around the submarine cable unit 18 due to seabed erosion or scour.

[0197] This alternative foundation device (74) has the further advantage of enabling the installation of the submarine cable unit 18 in locations where erosion has created a free span between the landing point of the submarine cable unit 18 and the construction position of the submarine cable unit 18 at the time of installation. Therefore, this alternative foundation device (74) enables the installation of the submarine cable unit 18 while suspended above the level of the seabed 17 or the level of the scour protection layer 15. Since it can provide an artificial landing base that elevates the submarine cable unit 18 above the level of the seabed 17 or the level of the scour protection layer 15, installation can be carried out without changing the catenary shape (and therefore without changing the tension of the submarine cable unit 18).

[0198] The foundation device 74 may also be used when erosion is expected due to localized water flow conditions. In this case, the foundation device 74 is installed before the installation of the submarine cable unit 18, or at the same time as the installation of the submarine cable unit 18, using the same procedure.

[0199] Figure 34 shows that a submarine cable unit 18 is installed, and that the submarine cable unit 18 extends from a position above the seabed 17 or the scour prevention layer 15, for example, from a submarine structure (not shown in the figure), down to the seabed 17 or the scour prevention layer 15.

[0200] Over time, as erosion of the seabed 17 and / or the scour protection layer 15 progresses, the submarine cable unit 18 may become suspended (hanging) above the seabed 17 or the scour protection layer 15. This is shown in Figures 35 and 38, where the submarine cable unit 18 is located at a distance D above the seabed 17 or the scour protection layer 15. This condition can increase tension on the submarine cable unit 18 and cause changes in its catenary shape. As a result, the wear of the submarine cable unit 18 may increase.

[0201] As shown in Figures 36 to 40, the foundation device 74 can be used to mitigate erosion problems of the seabed 17 and / or the scour protection layer 15 around the submarine cable unit 18.

[0202] Figure 36 shows two foundation devices 74, each equipped with a pile element 75. The pile element 75 is located in the seabed 17 and / or the scour protection layer 15 at its lower section 79. A free section 78 exists between the upper section 76 and the lower section 79.

[0203] An attachment unit 77 is attached to the upper part 76 of the pile element 75. This attachment unit 77 is securely attached to the pile element 75 using appropriate means (e.g., bolts or welding).

[0204] Each base unit 74 further includes a support element 80 that is attached to a mounting unit 77 and supports a submarine cable unit 18. The support element 80 is preferably adjustable to the mounting unit 77, but may also be securely attached to the mounting unit 77 by bolts or other suitable fastening means. To position the support element 80 adjustablely on the mounting unit 77, corresponding screws are provided on the support element 80 and the mounting unit 77, and the support element 80 can be adjusted to a desired position by being screwed in vertically on the mounting unit 77. Once the support element 80 is in a predetermined position, it can be secured to the mounting unit 77 by a suitable locking mechanism (not shown in the figure).

[0205] The support element 80 preferably has a conical support surface 81 as shown in the figure. The pile element 75 is positioned at an inclination with respect to a vertical line with respect to the seabed 17 and / or scour prevention layer 15. The angle of the conical support surface 81 can be adjusted to match the inclination angle of the pile element 75 so that the submarine cable unit 18 rests on a nearly horizontal surface.

[0206] As shown in Figure 36, the two foundation devices 74 are installed at an angle to each other and to the seabed 17 or scour-preventing layer 15, clearly forming a scissor shape. Furthermore, the submarine cable unit 18 rests on the support surface 81 of the support element 80.

[0207] Figures 37 and 38 further illustrate the installation of the bend stiffener unit 85. The bend stiffener unit 85 comprises a bend stiffener body 86. This bend stiffener body 86 has an approximately semi-domed cross-sectional shape so as to fit on top of the submarine cable unit 18. In Figure 38, it is clearly shown that the submarine cable unit 18 is supported by support elements 80 at a distance D above the level of the seabed 17 or the scour protection layer 15.

[0208] The bending reinforcement unit 85 further comprises four attachment elements 87 that are securely attached to the bending reinforcement body 86 and extend outward from the bending reinforcement body 86. As shown in the figure, two attachment elements 87 are positioned on each side of the bending reinforcement body 86. The distance between two attachment elements 87 positioned on the same side in the longitudinal direction of the bending reinforcement body 86 is adjusted so that the attachment unit 77 and the locking element 82 fit between the two attachment elements 87.

[0209] The bending reinforcement device unit 85 reduces the risk of damage to the submarine cable unit 18 by controlling the bending of the submarine cable unit 18 after its installation.

[0210] Figures 39 and 40a to 40b show the bending reinforcement device unit 85 already positioned on the submarine cable unit 18. As mentioned above, the bending reinforcement body 86 of the bending reinforcement device unit 85 has a semi-dome shape, so it fits on top of the submarine cable unit 18.

[0211] When the bending reinforcement device unit 85 is placed on the submarine cable unit 18, the locking element 82 is placed on the mounting unit 77. This locks the bending reinforcement device unit 85 and the submarine cable unit 18 following the bending reinforcement device unit 85 in place.

[0212] The locking element 82 is preferably adjustably positioned on the mounting unit 77 along the longitudinal direction of the pile element 75. The locking element 82 and the mounting unit 77 are, for example, equipped with corresponding screws. The ability of the locking element 82 to be screwed up and down along the mounting unit 77 allows the bending reinforcement device unit 85 to be adjusted to lock in place on the submarine cable unit 18. Once positioned, the locking element 82 is secured to the mounting unit 77 by a suitable locking mechanism (not shown in the figure).

[0213] The mounting element 87 is preferably wedge-shaped and has a mounting element contact surface 88 as shown in the figure. Furthermore, the locking element 82 has a locking element contact surface 83. Since this locking element contact surface 83 is conical, it contacts the mounting element 87 located on the opposite side of the locking element 82 after the bending reinforcement device unit 85 is installed. The wedge-shaped mounting element 87 ensures a favorable angle between the locking element contact surface 83 and the mounting element contact surface 88, thereby achieving better cooperation. [Explanation of symbols]

[0214] 10…Underwater systems. 11...Undersea structure. 12... Monopile / Monopile foundation.

[0215] 13…Cable entry / opening (inside a monopile for a submarine cable unit). 14… Connector / latch / interface unit (cable protection system at cable entry / opening).

[0216] 15…Scour protection layer. 16...Scouer Pit / Scouer Hall. 17...Undersea.

[0217] 18… Submarine cable unit. 19... Cable. 20…Cable protection system.

[0218] 22...Stabilizer. 24...First stabilization base section. 25...Second stabilization base section.

[0219] 26... Stabilizing surface (of the first and / or second stabilizing base portion). 27…First clamping device. 28...Second clamping device.

[0220] 30… Absorbing device (included in the first and / or second clamping device). 31…First anchor section (for mounting the absorber to the first and / or second stabilization device).

[0221] 32...Second anchor section (for attaching the shock absorber to the cowl unit). 34... Landing point (the touchdown point of the submarine cable unit on the seabed or in the scour-resistant layer).

[0222] 35…The center of the stabilization device (if located above, near, outside, or inside the landing point of the submarine cable unit). 36…Installation level of the stabilization device (level of the seabed or scour prevention layer at the time of installation).

[0223] 37... The level of the stabilization device has decreased (after the seabed level has dropped). 39... Clamping element. 40… Groove (within the clamping element).

[0224] 42…Through-hole (for pile elements, in the first and / or second stabilizing base or clamp element). 43... Guide element (for pile elements).

[0225] 45… Cowling unit. 46… Tip (of the cowling unit (flexible tip)). 47… Dome center (of the cowling unit).

[0226] 48… Horizontal part (of the cowling unit). 49… Side part (of the cowling unit). 51… Movement restraining element (friction pad / friction layer provided in the cowling unit to restrain the movement of the subsea cable unit or slots / cavities / grooves / depressions provided in the horizontal part of the cowling unit).

[0227] 52… First catenary (of the subsea cable unit during installation). 53… Second catenary (after the subsea cable unit has dropped to the seabed level). 54… Pile element.

[0228] 55… Lower part (anti-scouring layer and / or part penetrated into the seabed). 56… Upper part. 57… Operation interface (for remotely operated vehicle ROV).

[0229] 59… Inflation device. 60… Compressed state (of the inflation device) 61… Relaxed state (of the inflation device).

[0230] 62… Adjustment device (for tension adjustment of the inflation device). 64… Deformation device. 65… Lateral stay.

[0231] 66… Compression area (on the stabilization base part). 67… Attachment point (where the lateral stay is attached to the cowling unit). 68… Bend stress relief base part.

[0232] 69… Bend reinforcement section. 70… Stabilization base part (integrated with the bend stress relief base part and / or the bend reinforcement section).

[0233] 72... A trumpet-shaped semi-cone (in place of the cowl unit). 73... Bar. 74... Foundation device (comprising a pile element with a mounting unit and support elements, and a locking element adjusted to be attached to the mounting unit).

[0234] 75…Pile element (penetrating the seabed and / or erosion-resistant layer). 76... Upper part (of the pile element). 77…Mounting unit (attached to the top of the pile element, for mounting the support element and locking element. For example, the mounting unit has threaded portions corresponding to the support element and / or locking element).

[0235] 78...Free portion (the portion of the pile element; the portion between the upper part and the seabed or the Scoua Formation). 79...Lower part (the pile element portion, located on the seabed and / or in the Skua Formation). 80...Support element (located in the mounting unit of the pile element, supporting the submarine cable unit).

[0236] 81...Support element support surface (the surface of the support element; it may have a conical surface on which the submarine cable unit rests). 82... Locking element (located on the support element and on the mounting unit of the pile element, locking the submarine cable unit and the bending reinforcement device unit in place).

[0237] 83... Locking element contact surface (the surface of the locking element; it may have a conical surface that contacts the mounting element). 85... Bending reinforcement device unit (controls the bending of submarine cable units).

[0238] 86... Bending reinforcement. 87…Mounting element (attached to the bending reinforcement unit, positioned between the support element and the locking element, and adapted / adjusted in shape to lock the bending reinforcement unit onto the foundation pile in the position of the submarine cable unit).

[0239] 88... Mounting element contact surface (the surface of the mounting element; it may have a conical surface that contacts the locking element).

Claims

1. A stabilization device (22) for a submarine cable unit (18), The submarine cable unit (18) extends between the seabed (17) and a cable inlet (13) on a submarine structure (11), the cable inlet (13) being located above the seabed (11), and the submarine cable unit (18) is configured to include a submarine cable equipped with a cable protection system (20) or to include only a submarine cable. The stabilizing device (22) is At least one stabilizing base portion (24, 25) and A first clamping device (27) is securely fixed to one end of at least one of the stabilizing base portions (24, 25), wherein the first clamping device (27) is curved and is configured to at least partially surround and hold the submarine cable unit (18) when at least one of the stabilizing devices (22) and the submarine cable unit (18) are installed, A second clamping device (28) securely fixed to one end of at least one of the stabilizing base portions (24, 25), wherein the second clamping device (28) is curved and is configured to at least partially surround and hold the submarine cable unit (18) when at least one of the stabilizing devices (22) and the submarine cable unit (18) are installed, and At least one pile element (54) for anchoring at least one of the stabilizing base portions (24, 25) to the seabed (17) or scour-resistant layer (15), wherein at least one of the stabilizing base portions (24, 25) is reliably anchored to the seabed (17) or the scour-resistant layer (15), and the pile element (54) is adapted to be driven into the seabed (17) or the scour-resistant layer (15) such that the stabilizing device (22) is positioned above the landing point (34) of the submarine cable unit (18) when the stabilizing device (22) is installed, A stabilization device equipped with the following features.

2. The first clamping device (27) and the second clamping device (28) are attached to at least one of the stabilizing base portions (24, 25), The first clamping device (27) is located closer to the seabed structure (11) than the second clamping device (28), The first clamping device (27) is flexible. The stabilization device according to claim 1.

3. The second clamping device (28) has higher rigidity than the first clamping device (27). A stabilization device according to claim 1 or 2.

4. At least one of the stabilizing base portions (24, 25) is provided with at least one through hole (42), At least one of the pile elements (54) is adapted to pass through the through hole (42), A stabilization device according to any one of claims 1 to 3.

5. The stabilizing device (22) comprises at least one clamping element (39) having at least one through hole (42) for at least one of the pile elements (54). A stabilization device according to any one of claims 1 to 4.

6. At least one of the pile elements (54) is equipped with an expansion device (59) that applies force to at least one of the stabilizing base portions (24, 25) in the direction of the seabed (17) or the scour prevention layer (15). A stabilization device according to any one of claims 1 to 5.

7. The expansion device (59) is adapted to expand in such a way that, when the seabed (17) or the erosion prevention layer (15) is eroded, it exerts a continuous force on at least one stabilizing base portion (24, 25) in the direction of the seabed (17) or the erosion prevention layer (15). The stabilization device according to claim 6.

8. At least one of the pile elements (54) is provided with an adjustment device (62) for adjusting the force applied to at least one of the stabilizing bases (24, 25) by adjusting the tension within the expansion device (54). The stabilization device according to claim 6 or 7.

9. The stabilization device (22) further includes a cowl unit (45) for controlling the bending of the submarine cable unit (22), The cowl unit (45) is curved and surrounds the submarine cable unit (22) at least partially in the circumferential direction, The cowl unit (45) and the submarine cable unit (22) are held by the first clamping device (27) and the second clamping device (28). A stabilization device according to any one of claims 1 to 8.

10. The cowl unit (45) is further curved along the longitudinal direction of the submarine cable unit (22) to prevent the submarine cable unit (22) from bending beyond a desired angle. The stabilization device according to claim 9.

11. The cowl unit (45) is provided with at least one motion-retaining element (51) on the side facing the submarine cable unit (22), At least one of the motion-retaining elements (51) is pressed against the submarine cable unit (22), The stabilization device according to claim 9 or 10.

12. The stabilization device (22) comprises a first stabilization base (24) and a second stabilization base (25), Each of the first stabilizing base portion (24) and the second stabilizing base portion (25) has at least one through hole (42) for at least one of the pile elements (54), At least one of the pile elements (54) is fitted into at least one of the through holes (42) and is adapted to be driven into the seabed (17) or the erosion prevention layer (15), This ensures that the first stabilizing base (24) and the second stabilizing base (25) are securely anchored to the seabed (17) or the scour prevention layer (15). A stabilization device according to any one of claims 1 to 11.

13. The first clamping device (27) is securely attached to the first stabilizing base (24) at one end and securely attached to the second stabilizing base (25) at the other end. The second clamping device (28) is securely attached to the first stabilizing base (24) at one end and securely attached to the second stabilizing base (25) at the other end. The stabilization device according to claim 12.

14. The first clamping device (4) comprises at least one dynamic absorber (30), the dynamic absorber (30) being anchored at one end to a first stabilizing base (24) and / or a second stabilizing base (25), and at the other end to a cowl unit (45). A stabilization device according to any one of claims 1 to 13.

15. The first stabilizing base portion (24) and / or the second stabilizing base portion (25) are provided with a plurality of through holes (42) for the pile element (54), The pile element (54) is fitted into the corresponding through hole (42) and is adapted to be driven into the seabed (17) or the scour prevention layer (15), thereby enabling the first stabilizing base (24) and / or the second stabilizing base (25) to be securely anchored to the seabed by the multiple pile elements (54). A stabilization device according to any one of claims 12 to 14.

16. At least one through hole (42) is provided with a guide element (43) to facilitate the insertion of at least one of the pile elements (54) into at least one of the through holes (42) when the stabilizing device (22) is installed. A stabilization device according to any one of claims 4 to 15.

17. At least one of the pile elements (54) is adapted for handling by a remotely operated vehicle (ROV). A stabilization device according to any one of claims 1 to 16.

18. The submarine cable unit (22) is equipped with the cable protection system (20). A stabilization device according to any one of claims 1 to 17.

19. The seabed structure (11) is securely installed within or on the seabed (17). A stabilization device according to any one of claims 1 to 18.

20. A submarine system (10), wherein the submarine system (10) is A seabed structure (11) that is located within or securely installed on the seabed (17), A submarine cable unit (18) extending between the seabed (17) and the cable inlet (13) on the submarine structure (11), It is equipped with, The cable entrance (13) is located above the seabed (17), The submarine cable unit (18) is configured to include a submarine cable equipped with a cable protection system (20), or to include only a submarine cable. The submarine system (10) is equipped with a stabilization device (22) according to any one of claims 1 to 19 for stabilizing the submarine cable unit (18). Submarine systems.

21. The stabilization device (22) is positioned on the scour prevention layer (15) which is already placed on the seabed (17) adjacent to the seabed structure (11). The seabed system according to claim 20.

22. The stabilizing device (22) is located directly on the seabed (17). The seabed system according to claim 20.

23. The aforementioned seabed structure (11) is a monopile (12) of a wind power plant securely fixed to the seabed (17). The seabed system according to any one of claims 20 to 22.

24. To stabilize the submarine cable unit (18) from the offshore wind power plant, Use of the stabilizing device (22) according to any one of claims 1 to 19, and / or Use of the subsea system (10) according to any one of claims 20 to 23.

Images