A cable securing device for securing a submarine cable

Abstract

The application relates to a cable securing device (100, 200, 300, 500) for securing a submarine cable (110, 310, 510) during a pulling-in process of the submarine cable (110, 310, 510) during an installation of the submarine cable (110, 310, 510) to an offshore structure (112), comprising at least one fixing element (102) configured to fix the cable securing device (100, 200, 300, 500) to the offshore structure (112) and / or a cable installation tool (118), at least one cable feedthrough arrangement (104, 204, 304, 504) connected to the fixing element (102) and having at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) forming an intermediate space (128, 228, 328, 528), wherein the at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) are configured to allow the submarine cable (110, 310, 510) to move through the formed intermediate space (128, 228, 328, 528) during the pulling-in process in a pulling-in direction of the submarine cable (110, 310, 510), and wherein the at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) are configured to block a movement of the submarine cable (110, 310, 510) through the formed intermediate space (128, 228, 328, 528) in a direction opposite to the pulling-in direction.

Description

[0001] A cable securing device for securing a submarine cable

[0002] The application relates to a cable securing device for securing a submarine cable during a pulling-in process of the submarine cable during an installation of the submarine cable to an offshore structure. In addition, the application relates to an offshore structure, a use of a cable securing device and a method.

[0003] Nowadays, more and more offshore wind energy systems respectively offshore wind farms are being built. The advantage of an offshore site compared to an onshore site is, among other things, the regularly better wind conditions at an offshore site compared to an onshore site. These better wind conditions in turn lead to higher energy yields from the offshore wind farm.

[0004] The known offshore wind farms have each a plurality of offshore wind turbines. An offshore wind turbine may be a floatable or non-floatable offshore wind turbine. An offshore wind turbine is configured to convert kinetic wind energy into electrical energy.

[0005] The electrical energy thus generated is transmitted from an offshore wind turbine to an offshore feed point of the offshore wind farm via a submarine cable in the form of a power cable. As a rule, a plurality of offshore wind turbines is arranged in a string. One end of a string is connected to the offshore feed point. The other end of the string can be designed to be electrically connected to another end of another string as needed (e.g., in the event of a cable fault in one of the strings).

[0006] The generated electrical power is transmitted from the offshore wind turbines to the offshore feed point via a plurality of submarine cables. The offshore feed point is usually an offshore converter station or offshore substation. The offshore feed point can be connected to an (public) electrical grid via a grid connection (possibly with the interposition of an onshore grid connection point) and feeds the generated electrical energy respectively power into the connected electrical grid.

[0007] A problem with the offshore structures of an offshore wind farm, such as the offshore wind turbines and / or the offshore feed point, but also with other offshore structures that require a connection to a submarine cable, is the complex and costly installation of such a submarine cable to the offshore structure. More particularly, modern offshore structures, such as the offshore wind turbines and / or the offshore feed point, but also other offshore structures have a height of several meters up to more than 150 meters.

[0008] In order to install a submarine cable to such an offshore structure, it is necessary to pull-in the submarine cable from the seabed or from a vessel to a connection terminal of the offshore structure in a pulling-in process during the installation of the submarine cable. Usually, the submarine cable, in particular, the submarine cable end to be connected to the connection terminal of the offshore structure, is pulled-in by using a cable installation tool.

[0009] For instance, the cable installation tool comprises a winch or the like and a pulling wire. The pulling wire can be connected to the cable end of the submarine cable. Then, the pulling wire and thus the submarine cable can be pulled-in by using the winch of the cable installation tool.

[0010] In particular, it is common to pull-in the submarine cable vertically upwards from seabed level to a platform mounted inside or outside the offshore structure ata higher elevation using the cable installation tool.

[0011] In practice, occasionally a failure of a component of the cable installation tool, such as the winch or pulling wire, occurs during the pulling-in process. For example, the winch may fail or the pulling wire may break. This causes the submarine cable to fall down and sink to the seabed possibly being damaged in the process. Even if the submarine cable is intact then it still has to be salvaged at great expense and pulled-up again. To make matters worse, when the submarine cable falls down, it can damage the offshore structure and / or nearby vessels and injure the people involved in the installation process.

[0012] Therefore, it is an object of the present application to provide a possibility to reduce the previously described drawbacks of the prior art, and in particular, to increase the security of a pulling-in process of a submarine cable during the installation of the submarine cable to an offshore structure.

[0013] The object is solved according to a first aspect of the application by a cable securing device for securing a submarine cable during a pulling-in process of the submarine cable during an installation of the submarine cable to an offshore structure. The cable securing device comprises at least one fixing element configured to fix the cable securing device to the offshore structure and / or a cable installation tool. The cable securing device comprises at least one cable feedthrough arrangement connected to the fixing element. The cable feedthrough arrangement has at least two guide modules forming an intermediate space. The at least two guide modules are configured to allow the submarine cable to move through the formed intermediate space during the pulling-in process in a pulling-in direction of the submarine cable. The at least two guide modules are configured to block a movement of the submarine cable through the formed intermediate space in a direction opposite to the pulling-in direction.

[0014] In contrast to the prior art, the present application provides a way to reduce the previously described disadvantages and, in particular, to increase the safety of a pulling-in process of a submarine cable during installation of the submarine cable to an offshore structure by providing a cable securing device in which a submarine cable to be pulled-in can be moved through an intermediate space formed by at least two guide modules which are configured such that the submarine cable is movable only in the pulling-in direction. In other words, if a component of the cable installation tool fails and the submarine cable is at risk of falling down, the guide modules of the cable securing device ensure that a movement of the submarine cable in the direction opposite to the pulling-in direction is blocked and prevented, respectively. The submarine cable will therefore not fall down and sink to the seabed when using a cable securing device according to the application. A costly salvage process can be prevented. In addition, damages or injuries can be prevented.

[0015] The cable securing device of the present application can be used during a pulling-in process respectively pulling-up process of a submarine cable to be installed to an offshore structure.

[0016] The offshore structure is preferably an offshore wind energy structure, such as an offshore wind turbine or an offshore converter station and substation, respectively. In other variants of the application, the offshore structure may also be another offshore structure, such as an offshore photovoltaic structure (preferably comprising a plurality of photovoltaic modules) or an offshore hydrogen production structure, in particular, with a water electrolysis device.

[0017] The submarine cable is preferably a submarine power cable. In particular, a submarine power cable is configured to transmit electrical energy and power, respectively. The submarine power cable is preferably a medium-voltage submarine power cable (in particular between 3 kV to 30 kV) or a high-voltage submarine power cable (e.g. 60 kV to 110 kV) or a cable operating at an even higher voltage, such as an extra-high voltage cable (e.g. up to 500 kV).

[0018] The power capacity of a submarine cable according to the application is preferably between 3 MW and 2.5 GW. In addition, a submarine power cable may also be equipped for data transmission. During the installation of a submarine cable to an offshore structure, a cable end (comprising a plug) of the submarine cable is connected to a connection terminal of the offshore structure. In order to connect the cable end of the submarine cable to the cable terminal of the offshore structure a pulling-in process is conducted, in particular, by means of a cable installation tool. The cable installation tool may comprise at least a winch or the like and a pulling wire and pulling rope, respectively.

[0019] One end of the pulling wire can be connectable to the cable end of the submarine cable. After connecting the pulling wire to the cable end of the submarine cable, by means of the winch or a similar device, the submarine cable, in particular, the cable end of the submarine cable, can be pulled-in to the cable terminal (which can be several meters above the water surface, e.g. more than 50 meters above the water surface). In particular, the submarine cable can be pulled-in vertically upwards from seabed level to a platform (having said cable terminal) mounted inside or outside the offshore structure at a higher elevation using the cable installation tool.

[0020] The cable securing device according to the application comprises at least one fixing element. The fixing element is configured to fix and fasten, respectively, the cable securing device to the offshore structure or the cable installation tool. In a fixed state of the cable securing device, the cable securing device can be fixed to an outer side of the offshore structure, such as an outer wall or the like of the offshore structure, or it can be fixed within the offshore structure and an inner side of the offshore structure, respectively, such as an inner wall or the like.

[0021] Preferably, the cable securing device can be fixed by the at least one fixing element to the offshore structure. In principle, the fixing element respectively fastening element can be designed in any way, as long as it is ensured that the cable securing device is held securely, even if the weight of the submarine cable (e.g. due to a rupture of the pulling wire) acts on the cable securing device and thus on the at least one fixing element. For example, the fixing element can be configured to enable a screw connection, a welded connection and / or the like. Furthermore, the cable securing device according to the application comprises at least one cable feedthrough arrangement. This arrangement is connected to the at least one fixing element.

[0022] The cable feedthrough arrangement comprises at least two (cable) guide modules forming an intermediate space. In particular, the formed intermediate space serves as a guiding space for guiding the submarine cable to be installed through the cable feedthrough arrangement.

[0023] The at least two guide modules of the cable feedthrough arrangement are configured to allow and enable, respectively, the submarine cable to move through the formed intermediate space during the pulling-in process in a pulling-in direction of the submarine cable. In other words, during the pulling-in process, the submarine cable can be pulled-in through the formed intermediate space by means of the cable installation tool, such as the described pulling wire and winch. The pulling-in process is essentially unaffected by the cable securing device, i.e. essentially the same force has to be applied to pull up the submarine cable as without a cable securing device according to the application.

[0024] Further, the at least two guide modules of the cable feedthrough arrangement are configured to block a movement of the submarine cable through the formed intermediate space in a direction opposite to the pulling-in direction. In other words, during the pulling-in process, the submarine cable cannot be moved (i.e. fall) through the formed intermediate space in the opposite direction due to the configuration of the at least two guide modules as one-way guide modules.

[0025] A pulling-in direction is, in particular, a vertically upward direction (seen from the seabed) and the opposite direction is, in particular, a vertically downward direction. In particular, the at least two guide modules are configured and cooperate with each other in such a way that they hold the submarine cable clamped as soon as the submarine cable attempts respectively begins to move in the direction opposite to the pulling-in direction. In other words, the guide modules may contact the submarine cable such that a movement of the submarine cable in the direction opposite to the pulling-in direction is prevented due to the established frictional connection between the submarine cable and the at least two guide modules. In the pulling-in direction, a frictional connection cannot be established between the submarine cable and the at least two guide modules.

[0026] In a preferred embodiment, the cable feedthrough arrangement has exactly two guide modules. In other variants, the cable feedthrough arrangement comprises three or more guide modules forming the intermediate space. By providing three or more guide modules (e.g. four), the submarine cable can be accurately guided through the formed intermediate space. Further, the friction can be increased between the submarine cable and the cable securing device by using three or more guide modules (e.g. four).

[0027] Furthermore, according to a preferred embodiment, a distance between (the contact surfaces of) the first guide module and the second guide module may be between 90 % and 100 % of the diameter of the submarine cable, preferably between 95 % and 99 % of the diameter of the submarine cable.

[0028] According to a further embodiment of the cable securing device according to the application the at least two guide modules are evenly spaced in the circumferential direction of the formed intermediate space. In particular, in the case of exactly two guide modules, the two guide modules can be arranged on opposite sides of the formed intermediate space. In a simple manner, an intermediate space can be formed. In case of three or more guide modules which are evenly spaced in the circumferential direction the submarine cable can be guided particularly safely through the formed intermediate space. According to a preferred embodiment of the cable securing device according to the application, a first guide module (of the at least two guide modules) may comprise a first guide roller rotatable in one direction only (thereby allowing the submarine cable to move through the formed intermediate space during the pulling-in process only in the pulling-in direction of the submarine cable). A second guide module (of the at least two guide modules) may comprise a second guide roller rotatable only in one direction, (thereby allowing the submarine cable to move through the formed intermediate space during the pulling-in process only in the pulling-in direction of the submarine cable). For example, a guide roller with a ratchet mechanism or similar can provided.

[0029] In particular, the at least two guide rollers and guide wheels, respectively, each rotatable in one direction only are adapted to each other such that the submarine cable is allowed to move through the formed intermediate space during the pulling-in process only in the pulling-in direction of the submarine cable). In the other direction, a movement of the submarine cable can be prevented, since the guide rollers cannot be rotated in this direction.

[0030] Preferably, the first guide module can comprise a first roller support element arranged to support the first guide roller by a bearing element. Further, preferably, the second guide module can comprise a second roller support element arranged to support the second guide roller by a further bearing element. The first and / or second roller support element / s may be connected to the fixing module. If there are more than two guide modules with a guide roller, each guide module can be formed accordingly.

[0031] A bearing element of a respective guide roller may be configured such that the respective guide roller can only rotate in one direction. In the other direction, a rotation of the guide roller is, in particular, blocked. According to a further preferred embodiment of a cable securing device according to the application, during the pulling-in process, the first guide roller and the second guide roller may be configured to contact the submarine cable (in particular, by a contact surface in form of a running surface). The first guide roller and the second guide roller may be configured such that during the pulling-in process, a movement of the submarine cable in the pulling-in direction causes a rotating of the first guide roller and the second guide roller thereby allowing the movement of the submarine cable in the pulling-in direction.

[0032] In particular, each guide roller may be configured to allow unidirectional rotation only, as described hereinbefore. The first guide roller and the second guide roller may be configured such that during the pulling-in process, a movement of the submarine cable in the direction opposite to the pulling-in direction causes a blocking of rotating of the first guide roller and the second guide roller thereby blocking the movement of the submarine cable in the direction opposite to the pulling-in direction. In particular, a falling submarine cable can be held by the at least two guide rollers.

[0033] In particular, in order to prevent a movement of the submarine cable in the direction opposite to the pulling-in direction, according to a preferred embodiment, a distance between the first guide roller (in particular, the contact surface respectively running surface of the first guide roller) and the second guide roller (in particular, the contact surface respectively running surface of the second guide roller) is between 90 % and 100 % of the diameter of the submarine cable, preferably between 95 % and 99 % of the diameter of the submarine cable.

[0034] By providing a cable feedthrough arrangement with such a distance between the first and a second guide rollers, the submarine cable can be pulled-in through the formed intermediate space due to the guide rollers being rotatable in the pulling-in direction. In addition, a movement in the other direction can be prevented since the rollers are not rotatable in the other direction and the submarine cable is clamped between the rollers due to the distance smaller than the diameter of the submarine cable. A submarine cable can be easily pulled-in while the safety can be improved.

[0035] In a further embodiment, the cable feedthrough arrangement may comprise a distance adjustment mechanism configured to amend the distance between the first guide module and the second guide module between at least two distance values. Preferably, three or more different distances are settable by the distance adjustment mechanism. This enables to use the cable securing device for at least two different submarine cables with different cable diameters.

[0036] According to one embodiment, the cable securing device may comprise at least one roller pressing mechanism (e.g. with a spring element or the like ] configured to exert a first force on the first guide roller in the direction of the submarine cable arranged in the intermediate space and to exert a second force on the second guide roller in the direction of the submarine cable arranged in the intermediate space (thereby ensuring that the guide rollers are in contact with the submarine cable during the pulling-in process).

[0037] According to a further embodiment of the cable securing device according to the application, a running surface of the first guide roller and / or the second guide roller may be an uneven surface. In particular, each guide roller of the cable securing device may comprise an uneven running surface.

[0038] Preferably, an uneven surface may comprise spikes and / or ribs. In particular, a plurality of spikes may be substantially uniformly distributed over the entire running surface of a guide roller. Alternatively, a plurality of ribs may be substantially uniformly distributed over the entire running surface of a guide roller. In a variant of the application, a running surface may comprise both a plurality of spikes and a plurality of ribs. By providing an uneven running surface of a guide roller which contacts the submarine cable when arranged in the formed intermediate space, the friction between the submarine cable and the first guide roller and the second guide roller can be increased. Thereby, in case of a failure of a component of the cable installation tool a falling down of the submarine cable can be prevented in an even more secure manner.

[0039] According to a further embodiment of the cable securing device according to the application, a running surface of the first guide roller and / or of the second guide roller may be formed from a rubber material. Tests have shown that such a material is particular suitable for forming at least the respective running surfaces of a guide roller. In variants of the application, the whole guide roller can be made of rubber. In particular, the friction between the submarine cable and the first guide roller and the second guide roller can be increased. In other variants of the application, other materials can be used, such as a plastic material.

[0040] According to a further embodiment of the cable securing device according to the application, the first guide module may comprise a first tooth support element and a first tooth element connected to the first tooth support element at a first pivot. The second guide module may comprise a second tooth support element and a second tooth element connected to the second tooth support element at a second pivot. In particular, such a configuration can be used as an alternative to the previously described rolling configuration.

[0041] Furthermore, according to an embodiment of the cable securing device according to the application, the first guide module may comprise a first tooth pressing mechanism configured to exert a first force on the first tooth element in the direction of the submarine cable arranged in the intermediate space. The second guide module may comprise a second tooth pressing mechanism configured to exert a second force on the second tooth element in the direction of the submarine cable arranged in the intermediate space. A (first and / or second) tooth pressing mechanism may comprise a spring element. For instance, the (first and / or second) pivot may comprise a tooth pressing mechanism, for example, a torsion spring.

[0042] According to a further embodiment of the cable securing device according to the application, each of the first tooth element and second tooth element may comprise a contact surface contacting the submarine cable during the pulling-in process. The first tooth element and the second tooth element may be arranged at the respective pivot (e.g. each pivot comprising the tooth pressing mechanism, such as a torsion spring) such that during the pulling-in process, a movement of the submarine cable in the pulling-in direction causes a force acting on the respective contact surfaces radially outward from the cable axis of the submarine cable thereby allowing the movement of the submarine cable in the pulling-in direction. In particular, said force acting on the respective contact surfaces caused by the movement of the submarine cable may be greater than a spring force of the pressing mechanisms.

[0043] The first tooth element and the second tooth element may be arranged at the respective pivot (e.g. each pivot comprising the pressing mechanism, such as a torsion spring) such that during the pulling-in process, a movement of the submarine cable in the direction opposite to the pulling-in direction causes a force acting on the respective contact surfaces radially inward from the cable axis of the submarine cable thereby blocking the movement of the submarine cable in the direction opposite to the pulling-in direction. The force can be caused by the pressing mechanism. The submarine cable can be held by establishing a frictional connection between the contact surfaces and the submarine cable. In case of a failure of a component of the cable installation tool a falling down of the submarine cable can be prevented in an even more secure manner.

[0044] Generally, each tooth element may have an arbitrary form as long as it has a suitable contact surface for contacting the submarine cable. Preferably, each tooth element may have a wedge-shaped form. Further, each tooth is preferably formed from a rubber material. In other variants of the application, other materials can be used, such as a plastic material.

[0045] According to a further embodiment of the cable securing device according to the application, the cable feedthrough arrangement may comprise at least one release mechanism. The release mechanism may be configured to release a submarine cable from the formed intermediate space. For instance, the release mechanism may be a manually operable mechanism.

[0046] In particular, the release mechanism may be configured to release a submarine cable clamped by the at least two guide modules. In particular, after a failure of a component of the cable installation tool the submarine cable may be held in a clamped manner between the at least two guide modules. For instance, after securing the clamped submarine cable e.g. by a repaired cable installation tool or a new cable installation tool or the like, the release mechanism can release the submarine cable such that it can be removed from the cable securing device.

[0047] According to a further embodiment of the cable securing device according to the application, the fixing element may only be configured to temporarily fix the cable securing device to the offshore structure and / or the cable installation tool. In other words, the cable securing device is preferably a mobile cable securing device. This allows to use the mobile cable securing device for different installation processes e.g. at different offshore structures.

[0048] According to a further embodiment of the cable securing device according to the application, the cable securing device may comprise two or more cable feedthrough arrangements arranged above each other and connected to the at least one fixing element. In particular, a cable securing device can be provided with two or more (previously described) cable feedthrough arrangements arranged in series such that the submarine cable can be guided (without a deflection) through the intermediate spaces formed by each cable feedthrough arrangement. If necessary, the submarine cable can be held even more securely and prevented from falling.

[0049] A further aspect of the application is an (previously described) offshore structure or a (previously described) cable installation tool, comprising at least one previously described cable securing device.

[0050] A further aspect of the application is a use of at least one previously described cable securing device during the pulling-in of a submarine cable at an offshore structure for installing the submarine cable to the offshore structure.

[0051] A still further aspect of the application is a method for installing a submarine cable to an offshore structure, comprising: providing at least one previously described cable securing device, fixing the at least one securing device to the offshore structure by the fixing element of the cable securing device, and pulling-in the submarine cable through the formed intermediate space of the cable securing device.

[0052] In variants of the application, two or more previously described cable securing devices can be provided and used during the pulling-in process. In particular, after finishing the pulling-in process of the submarine cable, the submarine cable can be connected to a connection terminal of the offshore structure (in a conventional manner).

[0053] The cable securing device of the present application only allows movement of the submarine cable upwards during normal operation. As described in one embodiment, when the submarine cable moves upwards, relative to the device, e.g. the gripping teeth are pushed outwards and do not impede the cable's movement. However if the cable attempts to fall downwards the gripping teeth are forced into the cable thus holding it in position. There may be instances where it is desirable to release the cable and in these cases the user can manually pull back the teeth to prevent them gripping the cable by a release mechanism. Another embodiment of the application employs rollers respectively wheels which can only rotate in one direction, e.g. by use of a ratchet mechanism or similar. As the wheels can only rotate unidirectionally the cable is prevented from falling by the friction between the wheel and cable outer surface. It is noted that expressions such as "first", "second", etc. do not specify a series order, but only serve to distinguish between two elements (e.g. guide modules, guide rollers, etc.).

[0054] The features of the cable securing devices, offshore structures, uses and methods can be freely combined with one another. In particular, features of the description and / or the dependent claims, even when the features of the dependent claims are completely or partially avoided, may be independently inventive in isolation or freely combinable with one another.

[0055] These and other aspects of the present patent application become apparent from and will be elucidated with reference to the following figures. The features of the present application and of its exemplary embodiments, as presented above, are understood to be disclosed also in all possible combinations with each other.

[0056] In the figures show:

[0057] Fig. 1 a schematic view of an embodiment of an offshore structure according to the application with an embodiment of a cable securing device according to the application,

[0058] Fig. 2 a schematic top view of a further embodiment of a cable securing device according to the application, Fig. 3a-c schematic views of a further embodiment of a cable securing device according to the application in different states of an exemplified pullingin process,

[0059] Fig. 4a a schematic view of an exemplified running surface of a guide roller of an embodiment of a cable securing device according to the application,

[0060] Fig. 4b a schematic view of a further exemplified running surface of a guide roller of an embodiment of a cable securing device according to the application,

[0061] Fig. 5a-c schematic views of a further embodiment of a cable securing device according to the application in different states of an exemplified pullingin process, and

[0062] Fig. 6 a diagram of an embodiment of a method according to the application.

[0063] Similar reference signs in different Figures indicate similar elements. In addition, z denotes the vertical direction and x denotes a horizontal direction.

[0064] In the following embodiments, offshore wind turbines are depicted as offshore structures. However, the following explanations can be transferred to other offshore structures, such as offshore photovoltaic structures, offshore hydrogen production structures, etc.

[0065] Figure 1 shows a schematic view of an embodiment of an offshore structure 112, in particular, in the form of an offshore wind turbine according to the present application.

[0066] The offshore structure 112 comprises a foundation (e.g. a monopile anchored in the seabed 132) configured to support an offshore device (e.g. turbine tower with nacelle, etc.) comprising at least one (not shown) electrical device (e.g. a generator). The offshore device is in particular an electrical power generation device. The offshore wind turbine is configured to convert the kinetic energy of the wind into electrical energy.

[0067] The offshore structure 112 is shown during an installation process. In particular, as can be seen from Figure 1, a submarine cable 110 (e.g. a medium or high voltage cable) is being installed.

[0068] In order to install the submarine cable 110 to the offshore structure 112, it is generally necessary to (electrically and mechanically) connect a cable end 134 (e.g. in form of the plug) of the submarine cable 110 to a connection terminal 114 (e.g. in form of a socket) of the offshore structure 112.

[0069] For connecting the cable end 134 to the connection terminal 114, the submarine cable 110 is pulled-in respectively pulled-up, in particular, by a cable installation tool 118. For example, the cable installation tool 118 may comprise a winch 120 and a pulling wire 122 coupled to the winch 120, wherein the pulling wire 122 may be coiled and uncoiled by the winch 120. In variants, the cable installation tool can comprise other or more components.

[0070] One end of the pulling wire 122 can be coupled to the submarine cable 110, in particular, to the cable end 134 of the submarine cable 110. In particular, the submarine cable 110 can be pulled-in vertically upwards (i.e. in pulling-in direction 124) from seabed level to a platform 116 mounted inside or (presently) outside the offshore structure 112 at a higher elevation using the cable installation tool 118.

[0071] After completing the installation of the submarine cable 110, the generated electrical energy can be fed from the electrical device off the offshore structure 112 into the submarine power cable 110 via the connection terminal 114. In order to improve the safety during a pulling-in process of the submarine cable 110, at least one cable securing device 100 is provided and used. In variants of the application, two or more cable securing devices 100 can be used.

[0072] The depicted cable securing device 100 comprises at least one fixing element 102. As can be seen from Figure 1, the cable securing device 100 is fixed to the offshore structure 112 by means of the fixing element 102 (e.g. by welding, by a screw connection, etc.). The cable securing device 100 is fixed at an outer wall of the offshore structure 112 in a height above the water line 130 and below the platform 116 and below the connection terminal 114. In other variants of the application, the cable at least one securing device 100 can be fixed in another height (e.g. also at or below the water line).

[0073] The fixing element 102 is connected with at least one cable feedthrough arrangement 104 of the cable securing device 100. In other variants of the application, the cable securing device may comprise more than one cable feedthrough arrangement. The fixing element 102 and the cable feedthrough arrangement 104 can be welded together, formed in one piece or the like.

[0074] The cable feedthrough arrangement 104 is configured to guide the submarine cable 110 through the cable feedthrough arrangement 104 during the pulling-in process. In order to guide the submarine cable 110, the cable feedthrough arrangement 104 comprises at least two guide modules 106, 108. The first guide module 106 and the second guide module 108 are arranged such that an intermediate space 128 is formed between them.

[0075] As can be further seen from Figure 1, the submarine cable 110 is, in the depicted state, arranged within the formed intermediate space 128. In particular, the at least two guide modules 106, 108 are configured to allow the submarine cable to move through the formed intermediate space 128 during the pulling-in process in a pulling-in direction 124 (which is essentially a vertical direction) of the submarine cable 110. The at least two guide modules 106, 108 are further configured to block and prevent, respectively, a movement of the submarine cable 110 through the formed intermediate space 128 in a direction 126 (which is essentially a vertical direction) opposite to the pulling-in direction 124.

[0076] In particular, the at least two guide modules 106, 108 are configured and cooperate with each other in such a way that they hold the submarine cable 110 clamped as soon as the submarine cable attempts to move in the direction 126 opposite to the pullingin direction 124, e.g. due to a component failure of the cable installation tool 118.

[0077] Preferably, the guide modules 106, 108 are configured to contact the submarine cable 110 (directly) during the pulling-in process. The guide modules 106, 108 can be configured in such a way that movement of the submarine cable 110 in the pulling-in direction 124 is permitted despite the (continuous) contact with the guide modules 106, 108 during the pulling-in of the submarine cable 110 (i.e. vertically upwards), while a movement (in particular, a falling) of the submarine cable 110 in the opposite direction 126 is blocked respectively prevented by establishing a frictional connection between the guide modules 106, 108 and the submarine cable 110 (based on the contact of the guide modules 106, 108 with the submarine cable).

[0078] Figure 2 shows a schematic top view of a further embodiment of a cable securing device 200 according to the application. In order to avoid repetitions, in the following only the differences between the embodiment of Figure 1 and the embodiment of Figure 2 are essentially described. With regard to the other elements of the cable securing device 200 it is referred to the previous embodiment.

[0079] As can be seen from Figure 2, the cable feedthrough arrangement 204 connected to a fixing element 202 has at least two guide modules 206, 208 evenly spaced in the circumferential direction of the formed intermediate space 228. In particular, the two guide modules 206, 208 are arranged on opposite sides of the formed intermediate space 228. The distance 240 between the first guide module 206 and the second guide module 208 and the diameter of the formed intermediate space 228, respectively, can be designed such that it corresponds to the diameter of the (not shown) submarine cable to be guided through the formed intermediate space 228.

[0080] The distance 240 between the first guide module 206 and the second guide module 208 may be between 90 % and 100 % of the diameter of the submarine cable, preferably between 95 % and 99 % of the diameter of the submarine cable. In variants of the application, the feedthrough arrangement 204 may comprise a distance adjustment mechanism configured to amend the distance 240 between the first guide module 206 and the second guide module 208 between at least two distance values.

[0081] Figures 3a to 3c show schematic views of a further preferred embodiment of a cable securing device 300 according to the application in different states of an exemplified pulling-in process. In order to avoid repetitions, in the following only the differences between the embodiments of Figure 1 and / or 2 and the embodiment of Figure 3 are essentially described. With regard to the other elements of the cable securing device 300 it is referred to the previous embodiment.

[0082] The shown cable securing device 300 comprises a cable feedthrough arrangement 304 connected to a (not shown) fixing element. The cable feedthrough arrangement 304 comprises two guide modules 306, 308. In the present embodiment, the first guide module 306 comprises a first guide roller 354 respectively wheel rotatable in one direction only and the second guide module 308 comprises a second guide roller 352 respectively wheel also rotatable only in one direction.

[0083] Preferably, the first guide module 306 can comprise a first roller support element 350 arranged to support the first guide roller 354, in particular, by a bearing element 356. Further, preferably, the second guide module 308 can comprise a second roller support element 348 arranged to support the second guide roller 352, in particular, by a further bearing element 358. A bearing element 356, 358 of a respective guide roller 352, 354 may be configured such that the respective guide roller 352, 354 can only rotate in one direction. In the other direction, a rotation of the respective guide roller 352, 354 is, in particular, blocked.

[0084] As can be further seen from Figures 3a to 3c, the distance 340 between the first guide roller 354 and second guide roller 356 can be between 90 % and 100 % of the diameter 346 of the submarine cable 310, preferably between 95 % and 99 % of the diameter 346 of the submarine cable 310.

[0085] In Figure 3a, a state of the pulling-in process is depicted in which the submarine cable 310 being pulled-in by a pulling wire 322 has not yet reached the cable securing device 300, in particular, the intermediate space 328 formed between the first guide roller 354 and second guide roller 356.

[0086] In Figure 3b, a state of the pulling-in process is depicted in which the submarine cable 310 is within the formed intermediate space 328. In particular, during the pulling-in process, the submarine cable 310 is guided by the rotating guide rollers 352, 354 through the intermediate space 328. The rotating of the guide rollers 352, 354 is indicated by the arrows 364, 366. Due to the guide rollers 352, 354 rotating only when the submarine cable 310 is pulled-in the pulling-in direction 324, the submarine cable 310 can be easily pulled-in by the (not shown) cable installation tool.

[0087] In Figure 3c, a state of the pulling-in process is depicted in which a failure of a component of the cable installation tool occurs. For example, the pulling wire 322 breaks, as indicated in Figure 3c. Without the cable securing device 300 the submarine cable 310 would now fall down and sink to the seabed. The cable securing device 300 is configured to block such a movement of the submarine cable 310 in the direction 326 opposite to the pulling-in direction 324. As indicated in Figure 3c, the guide rollers 352, 354 cannot rotate in the other direction. Such a rotation is blocked. This (and in particular the selected diameter 340) causes that the guide rollers 352, 354 to hold the submarine cable 310 clamped as soon as the submarine cable 310 starts to move in the direction 326 opposite to the pulling-in direction 324. In particular, a frictional connection is established between the guide rollers 352, 354 and the submarine cable 310.

[0088] In order to provide a sufficient friction for establishing the frictional connection between the guide rollers 352, 354, the running surfaces 360, 362 of a respective guide rollers 352, 354 which contact the submarine cable 310 can be made of rubber (or a similar material) and / or can be uneven surfaces.

[0089] Figure 4a shows a schematic view of an exemplified running surface 462 of a guide roller 462 of an embodiment of a cable securing device according to the application, which can be used e.g. in Figure 3.

[0090] As can be seen from Figure 4a, the running surface 462 comprises a plurality of spikes 470. The spikes 470 can be made of rubber or another suitable material. In particular, the whole running surface 462 together with the spikes 470 are made from the same material. Preferably, the plurality of spikes 470 are evenly distributed over the total running surface 462 of the guide roller 462.

[0091] Figure 4b shows a schematic view of a further exemplified running surface 462 of a guide roller 454 of an embodiment of a cable securing device according to the application, which can be used e.g. in Figure 3.

[0092] In this embodiment, the running surface 462 comprises a plurality of ribs 472. The ribs 472 can be made of rubber or another suitable material. In particular, the whole running surface 462 together with the ribs 472 are made from the same material. Preferably, the plurality of ribs 472 are evenly distributed over the total running surface 462 of the guide roller 462. Figures 5a to 5c show schematic views of a further preferred embodiment of a cable securing device 500 according to the application in different states of an exemplified pulling-in process. In order to avoid repetitions, in the following only the differences between the embodiments of Figure 1 and / or 2 and / or 3 and the embodiment of Figure 5 are essentially described. With regard to the other elements of the cable securing device 500 it is referred to the previous embodiment.

[0093] The shown cable securing device 500 comprises a cable feedthrough arrangement 504 connected to a (not shown) fixing element. The cable feedthrough arrangement 504 comprises two guide modules 506, 508. The first guide module 506 comprises a first tooth support element 580 and a first tooth element 584 connected to the first tooth support element 580 at a first pivot 588. The second guide module 508 comprises a second tooth support element 582 and a second tooth element 586 connected to the second tooth support element 582 at a second pivot 590.

[0094] Preferably, the first guide module 506 comprises a first tooth pressing mechanism 581, in particular, in the form of a spring element, such as a torsion spring. The first tooth pressing mechanism 581 may be configured to exert a first force on the first tooth element 584 in the direction of the submarine cable 510 arranged in the intermediate space 528. Preferably, the second guide module 508 comprises a second tooth pressing mechanism 583, in particular, in the form of a spring element, such as a torsion spring. The second tooth pressing mechanism 583 may be configured to exert a second force on the second tooth element 586 in the direction of the submarine cable 510 arranged in the intermediate space 528. In other words, the spring force urges a respective tooth element to the center of the intermediate space 528.

[0095] In Figure 5a, a state of the pulling-in process is depicted in which the submarine cable 510 being pulled-in by a pulling wire 522 has not yet reached the cable securing device 500, in particular, the intermediate space 528 formed by the first and second tooth element 584, 586. In Figure 5b, a state of the pulling-in process is depicted in which the submarine cable 510 is within the formed intermediate space 528. In particular, during the pulling-in process, the submarine cable 510 is guided by the tooth elements 584, 586. Each of the first tooth element 584 and second tooth element 586 may comprise a contact surface 592, 594 contacting the submarine cable 510 during the pulling-in process.

[0096] As can be further seen from Figure 5b, the first tooth element 584 and the second tooth element 586 are arranged at the respective pivot 588, 590 (with the tooth pressing mechanism 581, 583) such that during the pulling-in process, a movement of the submarine cable in the pulling-in direction 524 causes a force acting on the respective contact surfaces 592, 594 radially outward (indicated by arrows 596, 598) from the cable axis of the submarine cable 510 thereby allowing the movement of the submarine cable 510 in the pulling-in direction 524. The submarine cable can (thus) be easily pulled-in by the (not shown) cable installation tool.

[0097] In Figure 5c, a state of the pulling-in process is depicted in which a failure of a component of the cable installation tool occurs. For example, the pulling wire 522 breaks, as indicated in Figure 3c. Without the cable securing device 500 the submarine cable would now fall down and sink to the seabed. The cable securing device 500 is configured to block a movement of the submarine cable 510 in the direction 526 opposite to the pulling-in direction 524.

[0098] As can be seen from Figure 5c, the first tooth element 584 and the second tooth element 586 are arranged at the respective pivot 588, 590 (with the tooth pressing mechanism 581, 583) such that during the pulling-in process, a movement of the submarine cable 510 in the direction 526 opposite to the pulling-in direction causes a force acting on the respective contact surfaces 592, 594 radially inward (indicated by arrows 596, 598) from the cable axis of the submarine cable 510 thereby blocking respectively preventing the movement of the submarine cable 510 in the direction 526 opposite to the pulling-in direction. The acting forces cause the tooth elements 584, 586 hold the submarine cable 510 clamped as soon as the submarine cable 510 starts to move in the direction 526 opposite to the pulling-in direction. In particular, a frictional connection is established between the tooth elements 584, 586 and the submarine cable 510. In order to provide a sufficient friction for establishing the frictional connection between the tooth elements 584, 586, at least the contact surfaces 592, 594 of a respective tooth element 584, 586 can be made of rubber (or a similar material) and / or can be uneven surfaces.

[0099] Figure 6 shows a diagram of an embodiment of a method according to the application. In particular, a method for installing a submarine cable to an offshore structure is shown.

[0100] In step 601, at least one cable securing device (e.g. as described in Figures 1, 2, 3 and / or 5) is provided.

[0101] In step 602, a fixing of the at least one cable securing device to the offshore structure by the fixing element of the cable securing device is conducted, as described hereinbefore.

[0102] In step 603, a pulling-in of the submarine cable occurs through the formed intermediate space of the cable securing device.

[0103] In an optional step 604, the submarine cable is connected to the connection terminal of the offshore structure.

Claims

C l a i m s1. A cable securing device (100, 200, 300, 500) for securing a submarine cable (110, 310, 510) during a pulling-in process of the submarine cable (110, 310, 510) during an installation of the submarine cable (110, 310, 510) to an offshore structure (112), comprising: at least one fixing element (102) configured to fix the cable securing device (100, 200, 300, 500) to the offshore structure (112) and / or a cable installation tool (118), at least one cable feedthrough arrangement (104, 204, 304, 504) connected to the fixing element (102) and having at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) forming an intermediate space (128, 228, 328, 528), wherein the at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) are configured to allow the submarine cable (110, 310, 510) to move through the formed intermediate space (128, 228, 328, 528) during the pulling-in process in a pulling-in direction of the submarine cable (110, 310, 510), and wherein the at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) are configured to block a movement of the submarine cable (110, 310, 510) through the formed intermediate space (128, 228, 328, 528) in a direction opposite to the pulling-in direction.

2. Cable securing device (100, 200, 300, 500) according to claim 1, characterized in that the at least two guide modules (106, 108, 206, 208, 306, 308, 506, 508) are evenly spaced in the circumferential direction of the formed intermediate space (128, 228, 328, 528).

3. Cable securing device (100, 200, 300, 500) according to claim 1 or 2, characterized in that a distance between the first guide module (106, 206, 306, 506) and the second guide module (108, 208, 308, 508) is between 90 % and 100 % of the diameter of the submarine cable (110, 310, 510), preferably between 95 % and 99 % of the diameter of the submarine cable (110, 310, 510).

4. Cable securing device (100, 200, 300, 500) according to any one of the preceding claims, characterized in that a first guide module (106, 206, 306, 506) comprises a first guide roller (354, 454) rotatable in one direction only, and a second guide module (108, 208, 308, 508) comprises a second guide roller (352) rotatable in one direction only.

5. Cable securing device (100, 200, 300, 500) according to claim 4, characterized in that during the pulling-in process, the first guide roller (354) and the second guide roller (352) are configured to contact the submarine cable (110, 310, 510), wherein the first guide roller (354) and the second guide roller (352) are configured such that during the pulling-in process, a movement of the submarine cable (110, 310, 510) in the pulling-in direction causes a rotating of the first guide roller (354) and the second guide roller (352) thereby allowing the movement of the submarine cable (110, 310, 510) in the pulling-in direction, and wherein the first guide roller (354) and the second guide roller (352) are configured such that that during the pulling-in process, a movement of the submarine cable (110, 310, 510) in the direction opposite to the pulling-in direction causes a blocking of rotating of the first guide roller (354) and the second guide roller (352) thereby blocking the movement of the submarine cable (110, 310, 510) in the direction opposite to the pulling-in direction.

6. Cable securing device (100, 200, 300, 500) according to any one of the preceding claims 3 to 5, characterized in that a running surface (360, 362, 462) of the first guide roller (354) and / or the second guide roller (352) is an uneven surface, wherein the at least one uneven surface comprises, in particular, spikes and / or ribs.

7. Cable securing device (100, 200, 300, 500) according to one of the previous claims 3 to 6, characterized in that a running surface (360, 362, 462) of the first guide roller (354) and / or of the second guide roller (352) is formed from a rubber material.

8. Cable securing device (100, 200, 300, 500) according to any one of the preceding claims, characterized in that the first guide module (106, 206, 306, 506) comprises a first tooth support element (580) and a first tooth element (584) connected to the first tooth support element (580) at a first pivot (588), and the second guide module (108, 208, 308, 508) comprises a second tooth support element (582) and a second tooth element (586) connected to the second tooth support element (582) at a second pivot (590).

9. Cable securing device (100, 200, 300, 500) according to claim 8, characterized in that the first guide module (106, 206, 306, 506) comprises a first tooth pressing mechanism (581) configured to exert a first force on the first tooth element (584) in the direction of the submarine cable (110, 310, 510) arranged in the intermediate space (128, 228, 328, 528), the second guide module (108, 208, 308, 508) comprises a second tooth pressing mechanism (583) configured to exert a second force on the second tooth element (586) in the direction of the submarine cable (110, 310, 510) arranged in the intermediate space (128, 228, 328, 528).

10. Cable securing device (100, 200, 300, 500) according to claim 9, characterized in that each of the first tooth element (584) and second tooth element (586) comprises a contact surface (592, 594) contacting the submarine cable (110, 310, 510) during the pulling-in process, wherein the first tooth element (584) and the second tooth element (586) are arranged at the respective pivot (588, 590) such that during the pulling-in process, a movement of the submarine cable (110, 310, 510) in the pulling-in direction causes a force acting on the respective contact surfaces (592, 594) radially outward from the cable axis of the submarine cable (110, 310, 510) thereby allowing the movement of the submarine cable (110, 310, 510) in the pulling-in direction, and wherein the first tooth element (584) and the second tooth element (586) are arranged at the respective pivot (588, 590) such that during the pulling-in process, a movement of the submarine cable (110, 310, 510) in the direction opposite to the pulling-in direction causes a force acting on the respective contact surfaces (592, 594) radially inward from the cable axis of the submarine cable (110, 310, 510) thereby blocking the movement of the submarine cable in the direction opposite to the pulling-in direction.

11. Cable securing device (100, 200, 300, 500) according to any one of the preceding claims, characterized in that the fixing element (102) is only configured to temporarily fix the cable securing device (100, 200, 300, 500) to the offshore structure (112) and / or the cable installation tool (118). In other words, the cable securing device is preferably a mobile cable securing device.

12. Offshore structure (112) or cable installation tool (118), comprising: at least one cable securing device (100, 200, 300, 500) according to any one of the preceding claims 1 to 11.

13. Use of at least one cable securing device (100, 200, 300, 500) according to any one of the preceding claims 1 to 11 during pulling-in of a submarine cable (110, 310, 510) at an offshore structure (112) for installing the submarine cable (110, 310, 510) to the offshore structure (112).

14. Method for installing a submarine cable (110, 310, 510) to an offshore structure (112), comprising: providing at least one cable securing device (100, 200, 300, 500) according to any one of the preceding claims 1 to 11 fixing the at least one cable securing device (100, 200, 300, 500) to the offshore structure (112) by the fixing element (102) of the cable securing device (100, 200, 300, 500), and pulling-in the submarine cable (110, 310, 510) through the formed intermediate space (128, 228, 328, 528) of the cable securing device (100, 200, 300, 500).

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