An adjustable marine aquaculture system

Abstract

A flexible elongated structure, the structure comprising an elongated fluid pouch provided inside a weave of coiled strands attached at each end to an anchor element. Increasing the volume of the pouch will expand the weave and thus shorten the distance between the anchor elements. This may be used as an actuator, a force sensor, a position sensor and / or as a power generator.

Description

[0001] AN ADJUSTABLE MARINE AQUACULTURE SYSTEM

[0002] The present invention relates to an adjustable marine aquaculture system or rather a flexible elongated structure which is controllable by a fluid flow and which may be employed as a one or any combination of a force sensor, a position sensor, an energy harvester, and an actuator.

[0003] Flexible elongated structures are known from e.g. mountaineering ropes which has ropes with a soft core surrounded by a weave of inextensible strands of material, so that the rope may be elongated whereby the soft core is compressed by the strands, until the core is sufficiently compressed. Ropes of this type are, however, not controllable. WO 2017 / 144858 Al relates to a flexible compliant line for providing a linkage between a first structure and a second structure. WO 2011 / 058178 discloses a pump comprises a flexible container filled with a fluid and having a fluid inlet and a fluid outlet, and a constricting device, preferably in the form of a braid tube, conforming the container to a generally circular cross-section and operable cyclically to reduce the diameter of the container to expel fluid from the outlet. However, further technical development is required to address additional functional and operational requirements beyond those disclosed in the cited documents.

[0004] A first aspect of the invention relates to a flexible elongated structure, the structure comprising:

[0005] an elongate, hollow and flexible container having an inlet,

[0006] a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements,

[0007] a fluid feederconfigured to feed fluid into and receive fluid from the elongate, flexible container via the inlet and a fluid conduit, the fluid feeder comprises a pump configured for feeding fluid into and / or out of the elongate, flexible container via the fluid conduit, and

[0008] a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase.

[0009] Inspicos / 10 / 03 / 2026 / 10:52In this context, a flexible sleeve is a structure which may be bent, stretched, compressed or the like. The present flexible sleeve is desired bendable to have its longitudinal axis bend. Additionally, it may be desired to allow the flexible sleeve structure to elongate or shorten, so that the distance between the first and second anchor elements is varied. This distance may be desired controlled and / or determined.

[0010] In some embodiments, the fluid feeder may further comprise a valve configured to block or allow flow. The valve may be configured for feeding fluid into and / or out of the elongate, flexible container via the fluid conduit. If the pressure difference is suitable, the valve may feed the fluid. Alternatively, or additionally, the pump may force the fluid flow.

[0011] The elongate, hollow and flexible container preferably is impermeable to the fluid so that it will contain an amount of the fluid even when the fluid is under pressure. The container is flexible so that it may expand at least in a direction at an angle to a longitudinal direction from the first anchor element to the second element. The container is hollow so as to be able to receive and hold the fluid. The flexible container may be of a non-stretchable material when still capable of obtaining the different shapes required by the distance variation between the first and second anchor elements and the variation in the cross-sectional area. One manner of obtaining this for a non-strechable material is to provide it with the desired shape and allowing it to have folds and the like inside the flexible sleeve, where a variation in one dimension may create or remove folds perpendicular to that dimension. An example of a material with low stretchability would be Dyneema, Polyester, ultra-high-molecular-weight-polyethylene (UHMWPE).

[0012] An alternative to a non-stretchable material clearly is providing a stretchable material which may stretch to accommodate the dimensional changes. An example of a very stretchable material would be rubber, and an example of intermediate stretchability materials could be Nylon and Nylon / Polyester blends.

[0013] The flexible container may be attached to one of or both anchor elements. One end of the flexible container may be attached to and closed by the first anchor element and the other end may be attached to and closed by the second anchor element. The flexible container may be formed from a tube and the inlet may be into the end of the flexible container engaged by the first anchor element.

[0014] Thus, the anchor element(s) may seal an opening in the flexible container, such as when the flexible container is formed from a tube of a flexible material where one end of the tube is attached to and closed by the first anchor element and the other end is attached to and closed by the second anchor element.

[0015] Inspicos / 10 / 03 / 2026 / 10:52The flexible container has an inlet which is an opening into the hollow inner of the flexible container. The inlet may be positioned at any position of the flexible container. It may be desired to have the inlet positioned at a portion of the flexible container engaging the first anchor element so that the inlet does not interfere with positions where the flexible container interacts with the flexible sleeve. The conduit may then extend through the first anchor element. Then, in the above tube example, the inlet may be an inlet into the end engaged by the first anchor element.

[0016] The anchor elements may be any type of element but are preferred to be configured to attach to or fix to other structures or elements, such as buoyancy elements, load elements, moorings, vessels, payloads, buoys, or the like. The buoyancy elements may comprise any type of interconnection element, such as hooks, screws, fastening eyes, snap locks, magnets, or the like.

[0017] The flexible sleeve is attached to the anchor elements. This attachment may be permanent or intermittent. Preferably, the attachment is capable of withstanding a predetermined minimum force, as the herein disclosed flexible structure may be used for anchoring / tethering elements while sensing a force / displacement thereof and / or adapting this distance.

[0018] The flexible sleeve has an inner space in which the flexible container is provided. Then, the flexible container is also positioned between the anchor elements. The flexible sleeve structure is flexible to be able to expand and contract at an angle to the above longitudinal direction. An increase in a volume of the flexible container may force the flexible sleeve to obtain a corresponding shape. Then, the flexible sleeve is simultaneously configured to reduce the distance between the first and second anchoring elements.

[0019] A number of different types of flexible sleeve may be employed. A preferred type is one comprising a plurality of strands of material each having a helical coil shape around the flexible container, each having a first end connected to the first anchor element and each having a second end connected to the second anchor element. The strands are then bendable to be able to follow any expansion and compression of the flexible container. Preferably, some strands have a different direction of rotation than others so that the strands may form a weave or braid around the flexible container. In this manner, the expansion of the flexible container at an angle to the longitudinal direction will expand the cross sectional area of the container and thus force the weave to expand. When the strands are at least substantially inextendible or unstretchable, the expansion of the flexible container will drag the two anchoring elements toward each other. On the other hand, a compression or reduction of the cross section of the flexible container will allow the anchor elements to distance more from

[0020] Inspicos / 10 / 03 / 2026 / 10:52each other. The expansion will alter the angle between the longitudinal direction and the direction of the strands.

[0021] Also, the operation of the strands will be to act to contain the flexible container during this operation. It may be desired that a sufficient number of or density of strands is provided to support the flexible container also when fluid is forced into it. It would be desirable that the flexible container does not form outwardly directed pockets between the strands, as these pockets will take up an unknown amount of the fluid, so that the expansion of the flexible sleeve is undetermined. Also, this may lead to rupture of the flexible container and thus failure of the overall structure. Naturally, the density of such strands will depend heavily on the properties of the flexible container. If it is made of a sturdy material, the density need not be high, but if the container is made of a more flexible material, a higher density may be desired.

[0022] In one embodiment, a maximum distance of 50mm, such as 20mm, such as 10mm, such as 5mm, such as 2mm, such as 1mm, such as 0.5mm, exists from all portions of an outer surface of the flexible container between the first and second anchor elements and to a strand. Additionally or alternatively, the maximum distance may be comparable to a thickness of the material of the flexible container, as this may act to keep the flexible container within the sleeve.

[0023] Due to the relative movements or deformations of the flexible container and flexible sleeve, wear and the like may take place between these. This will depend on the materials chosen, dimensions and the like. If a suitable set of materials and properties is not easily determined, it may be desired to provide an inner sleeve between the flexible sleeve and the flexible container. This inner sleeve may have desired properties toward the flexible container, such as reduced friction and / or a sleeve structure providing the above minimum distances thus maintaining the flexible container inside the flexible sleeve. The inner sleeve clearly also should be able to follow the variation in length and cross sectional area, and this may be obtained in any desired manner, so that the inner sleeve may be of a stretchable or non-stretchable material or may be a braid, weave, laser-cut or the like.

[0024] Flexible sleeves may also be employed which are not made of individual strands, such as structures which are laser cut or the like. Mesh structures, structures which define components in the longitudinal direction between the first and second anchor elements as well as components in the transverse direction may be used, as long as these elements are interconnected with angled elements which extend at an angle to the longitudinal direction and at an angle to the direction perpendicular thereto. Such angled elements are configured to alter their angle to the longitudinal direction as a function of the expansion of the flexible

[0025] Inspicos / 10 / 03 / 2026 / 10:52container. One such type of structure would be a hexagonal structure which has three sets of parallel sides and which may be deformed along any direction, where an extension along one direction will result in a contraction along a direction perpendicularly thereto.

[0026] In some embodiment, the flexible sleeve is biased toward a state in which little or no fluid is present in the flexible container.

[0027] In some embodiment, the flexible sleeve is biased toward a state in which a distance between the first and second anchor elements is below a threshold distance, such as to a minimum distance.

[0028] In some situations a bias toward a shorter state may be achieved by a shorter length of the inner flexible container, which must then be stretched to achieve the longer state. In some embodiments, the flexible container has a biased length shorter than a length of the flexible sleeve in a longer, extended state. As such, the flexible container may be shorter than the flexible sleeve. Thus, when connected with the anchors elements, the flexible container may have an offset tension.

[0029] In some situations a bias toward higher pressures within an inner flexible container may be achieved by having the diameter of the inner flexible container smaller than the diameter of the flexible sleeve in the shorter state. In some embodiments, the flexible container has a biased diameter smaller than an inner diameter of the flexible sleeve in a shorter, compact state. Thus, when provided as the hydraulic rope, the flexible container will have an offset pressure towards the flexible sleeve.

[0030] These configurations of the inner flexible container may lead to an efficient way of controlling and improving the flexible elongated structure when it is operated for various purposes as described herein.

[0031] In some situations, it is desired that the flexible sleeve is biased toward a state in which little or no fluid is present in the flexible container. Then, the flexible sleeve is biased against a state in which the distance between the first and second anchor elements is maximum or above a threshold distance. In this situation, removal of fluid from the flexible container, or allowing the fluid to escape the flexible container, will reduce the cross section of the flexible container, allowing the flexible sleeve to move toward the biased state, often called rest state.

[0032] The biassing of the flexible sleeve may be obtained in a number of manners, such as by preheating the flexible sleeve while in this state. Cooling the flexible sleeve may result in the

[0033] Inspicos / 10 / 03 / 2026 / 10:52structure being biased toward this state and thus create a force toward this state when deformed away from the state.

[0034] In general, the distance between the first and second anchor elements may be controlled by the amount of fluid in the flexible container. When this amount is increased, the first and second anchor elements are forced toward each other. For example, the first and second anchor elements may be forced toward each other when a thread angle is between 0 and 54 degrees. Having the flexible sleeve to revert to the more extended state when fluid is removed would then require a force dragging the anchor elements from each other. However, employing the biassing of the flexible sleeve toward this state will force the anchor elements away from each other. Both translations or movements of the anchor elements may be determined or defined by the added or removed amounts of fluid.

[0035] In another embodiment, the flexible sleeve and / or the flexible container is biased toward a state in which a distance between the first and second anchor elements is minimum and / or below a threshold distance, so that if this distance is increased, the flexible sleeve and / or container will operate to again reduce the distance.

[0036] It is noted that in the preferred embodiment comprising a braided flexible sleeve, the angle between the individual strands of the braid may depend on the expansion there of and thus the distance between the anchor elements. A minimum angle to the longitudinal axis may be seen when the distance between the anchor elements is maximum. This angle may not be perpendicular to the longitudinal direction as the strands still extend around the flexible container. Similarly, the angle to the longitudinal direction may be maximum when the distance between the anchor elements is minimum. This angle may not be perpendicular to the longitudinal direction as the anchor elements still will have the flexible sleeve and container between them. It is presently assumed that the maximum angle may be on the order of 54 degrees.

[0037] As used herein, a hydraulic rope refers to a structure comprising flexible elongated sleeve, inner flexible elongated container, anchor elements at each end. The anchor elements may be configured to allow flow of fluid into the inner flexible elongated container at one or both ends. When the anchor elements are pulled apart, they are configured to deliver tension primarily onto the flexible elongated sleeve and to deliver compression on the inner flexible elongated container. The hydraulic rope may therefore be at least a part of the flexible elongated structure as disclosed herein.

[0038] The hydraulic rope is preferably configured to be used in a body of water, even though the hydraulic rope may also be used on the ground. The hydraulic rope is fluid controllable and

[0039] Inspicos / 10 / 03 / 2026 / 10:52has the advantage that its buoyancy is easily controlled to have density above or below ambient water through the density of the fluid used to fill it.

[0040] For example, the hydraulic rope will be affected by the external pressure generated by the water depending on the depth at which the hydraulic rope sits. However, the fluid feeder may be provided with a fluid container, which is flexible and exposed the surrounding water pressure, the fluid feeder may be provided at least substantially at the same depth (such as if the fluid feeder is fixed to one of the anchor elements) so that the hydraulic rope is exposed to the same external pressure when not in tension. This makes movement of the fluid rather easy.

[0041] The fluid preferably is incompressible, such as water.

[0042] A fluid feeder is provided for feeding fluid from the feeder to the inlet of the hydraulic rope, via the conduit, or from the hydraulic rope to the feeder. Thus, the amount of fluid in the hydraulic rope may be controlled and optionally also determined or metered by the feeder. Then, the fluid feeder preferably comprises a pump for feeding fluid into the hydraulic rope.

[0043] In general, the hydraulic rope or the flexible elongated structure as descried herein may be used as a force sensor. When the hydraulic rope comprises fluid and the anchor elements are pulled away from each other, the fluid will be under pressure, as the flexible sleeve exerts a compression force to it. Clearly the force will depend heavily on material parameters and the like, but a range of pressure sensitivity to applied force by dragging the anchor elements apart will be obtainable (as seen on Figure 6 where pressure sensitivity to sleeve diameter and thread angle is calculated assuming constant external pressure and descried under drawings). Real values would be more complex, depending on thread properties and weave pattern and stretchability. Thus, the force is easily and precisely quantified.

[0044] The pressure change per increase of force may depend on the external water pressure and thus the depth of the structure, so it may be preferred to also determine a depth of the structure to use this parameter in the determination of the force or any other parameter determined. The pressure difference between a point inside and outside of the hydraulic rope anywhere along its length may be a function of pulling force between the hydraulic rope anchors independent of depth of that location.

[0045] The use of the word thread means a single thread or weave of threads collected together forming a whole making aforesaid thread angle to the direction between the end anchors. The use of the word thread may be used interchangeably with wording strand.

[0046] Inspicos / 10 / 03 / 2026 / 10:52During this use as a force sensor, fluid flow into and out of the hydraulic rope or the flexible container may be blocked, but it may also be allowed to allow length variation during the sensing.

[0047] All previous embodiments of the hydraulic rope may be useful as a force sensor, as any increase of the distance between the anchor elements will expel fluid from the flexible container, and the amount is defined by the distance of the increase. In addition or alternatively, a force acting to separate the anchor elements from each other will affect the pressure of the fluid in the flexible container, as this force will act on the flexible sleeve to compress the flexible container. This force may then be determined from the pressure of the fluid in the container. Then, different types of sensor may be obtained from the same set-up, such as depending on the manner in which fluid is allowed to exit the flexible container.

[0048] Then, for several reasons, it would be preferable to also provide means for quantifying an amount of fluid entering and / or exiting the flexible container and / or means for quantifying a pressure of the fluid in the flexible container.

[0049] In some embodiments the hydraulic rope can be attached to a Buoy-tube, which is a buoyancy structure, to which cultured organisms (e.g. shellfish or seaweed) are attached, also referred to as livestock.

[0050] In some embodiments, the flexible elongate structure, or the hydraulic rope, comprises a pressure sensor configured to measure a pressure of the fluid, such as in the flexible container or in the hydraulic rope. Internal pressure may be correlated with tensile force acting on the structure, subject to the geometric characteristics of the flexible sleeve. Accordingly, pressure measurement may be a basis for real-time calculation of pulling force and thereby facilitating a control of tension on the structure, such as on the flexible sleeve. Pressure within the hydraulic rope may be a measure of weight of livestock or provide a means to measure weight of livestock which is attached to a Buoy-tube.

[0051] In some embodiments, the flexible elongated structure, or the hydraulic rope comprises a sensor, such as a flow-meter, configured to measure amount of fluid moved into or out of the fluid feeder and / or the hydraulic rope and / or the flexible container and / or the buoyancy elements attached to the elongated structure or to the hydraulic rope. The fluid may be incompressible, and changes in measured fluid volume within the hydraulic rope may correspond to changes in axial length of the flexible sleeve, and therefore the depth of a buoyancy structure which it is attached to, such as Buoy-tube.

[0052] Inspicos / 10 / 03 / 2026 / 10:52This implies that the herein disclosed technology further relates to a system comprising a plurality of elongated structures (according to any one of the herein disclosed technology) attached to a buoyancy structure, the buoyancy structure comprising hollow elongated tube (Buoy-tube) comprising a plurality of water bags within the buoy tube and a first incompressible fluid, e.g. water within the water-bags.

[0053] At the beginning of a cultivation period, the livestock weight is known. During initial setup of the Buoy-tube, a target pressure can be measured or determined within each hydraulic rope. As the livestock of cultivated organisms, e.g. shellfish, grow and change in weight, the buoyancy of the overall structure may be configured to counter those changes in weight. Change in weight may influence the pressure within the hydraulic rope. Because the volume of the fluid within the hydraulic rope may be incompressible, the length remainsconstant (e.g. the overall structure may not move), but the pressures within the hydraulic ropes may change.

[0054] From here, measurement of livestock changes can be done in at least two ways as described in the following.

[0055] Firstly, if the hydraulic rope is vertical, the pressure deviation from target pressure may be calculated into force difference which is proportional to livestock weight change.

[0056] Secondly, an amount of first fluid may be moved into or out of the buoyancy elements (Buoytube), such that pressures measured within the hydraulic ropes reach target pressures again. That amount is proportional to a change in livestock weight. The amount of the fluid transferred to the water-bags of the Buoy may be measured by means of a fluid flow meter. The amount of the first fluid, that is in the water-bags, may be used to increase or decrease buoyancy, such as by transferring fluid into or out of water-bags of the Buoy-tube. During this use as a force sensorof the herein described elongated structure, the structure thus may further be connected to a Buoy-tube having a plurality of water-bags and fluid flow into and out of the hydraulic rope or the flexible container may be blocked. But the fluid in a and out of the water-bags may be allowed to increase and decrease buoyancy. In both cases, the buoyancy of the Buoy-tube may be adjusted to reach the initial target pressure value. Both embodiments may be used simultaneously to improve precision and / or for diagnostic purposes. Also both embodiments may work for increase and / or decrease in estimation of total weight of livestock, regardless of whether increased amount of livestock causes added or decreased weight in buoyancy of the livestock e.g. mussels or seaweed.

[0057] Summing up those changes may result in known livestock weight above sea level during cultivation period. Notice that the first fluid used within the buoyancy elements may be the

[0058] Inspicos / 10 / 03 / 2026 / 10:52same fluid as the one used for the hydraulic ropes, but it does not have to be. Buoy tubes and water bags are further described in relation with the drawings below.

[0059] In some embodiments, the structure comprises a control unit configured to receive sensor data from the pressure sensorand / or the flowmeter. The length of the flexible sleeve may be a function of material parameters and further geometrical construction and an inner volume of the elongate flexible container. Thus, the control unit may be configured to convert the pressure sensor data to the applied force on the ends of the flexible sleeve based on the geometry of the flexible container.

[0060] The force may forexample be pulling force by the flexible sleeve at both ends. The control unit may be configured to determine the force and based on the increase in the force, a weight change of livestock can be calculated. The control unit may be configured to activate a pump or a valve which allows fluid in or out of attached buoyancy elements. Advantageously, the structure may be maintained at a desired maximum height above bottom resulting in a known minimum depth from mean sea level (MSL). This is further described here below and also in relation with drawings.

[0061] In some embodiments, the structure comprises means configured to determine a force exerted by a hydraulic rope based on pressure measured within the elongate flexible container and the volume of fluid within the elongate flexible container.

[0062] In some embodiments, the control unit is configured to operate the pump to feed fluid into or out of the elongate, flexible container or a hydraulic rope, based on received sensor data representing volume of the fluid within the flexible container.

[0063] Based on pressure variation within hydraulic ropes, buoyancy of the structure (i.e. buoyancy elements) may be actively adjusted to maintain fixed pressure within the hydraulic ropes and thereby compensate for the increased / decreased weight of livestock.

[0064] In some embodiments, the control unit is configured to adjust the amount of fluid within a hydraulic rope, such as in the flexible container, in order to set a length of the hydraulic rope and thus set a maximum height of a structure above bottom, e.g. where submerged. The control unit may do this using a pump or if pressure difference allows by opening a valve. Thus, in some embodiments, the control unit is configured to adjust maximum height of a structure above bottom by changing volume within the elongate flexible container.

[0065] In some embodiments, the structure comprises pressure sensors configured to measure pressure ata reference reservoir and at a position on the structure and wherein the control

[0066] Inspicos / 10 / 03 / 2026 / 10:52unit is configured to determine a relative depth of the structure based on measured pressures. The structure may be submerged. The control unit may be configured to calculate the relative depth based on pressure difference between said measured pressures. Thus, the control unit may be configured to operate a pump or a valve or any other fluid displacement device to vary internal volume of hydraulic ropes, thereby adjusting its length and thereby to control the depth of the structure based on said volumetric measurements.

[0067] The pressure sensors may be configured to measure pressure within at least one hydraulic rope, wherein both pressure and transferred fluid volume may be a basis to determine a mechanical state of the structure. The control unit may be configured to adjust internal pressure, length, tension, or buoyancy of the structure. The control unit may be operatively connected to the pump and to vary the quantity of the fluid within the flexible container. The controller may be configured to operate the pump in response to sensor data representing displacement, pressure, fluid flow, or load. The control unit may be configured to calibrate a relationship between internal pressure of the flexible container, axial length of the flexible sleeve and / or the hydraulic ropes, and tensile force of the structure based on sensor data. The control unit may be configured to maintain a target structural parameter selected from axial length, tensile force, depth, or buoyancy.

[0068] In addition to the sensing and actuating embodiments, the hydraulic rope may additionally act as a power generator or as a pump.

[0069] Thus, a second aspect of the invention relates to a power generator comprising a flexible elongated structure according to the first aspect further comprising means for deriving energy from a flow of fluid into and / or out of the flexible container, e.g. the hydraulic rope.

[0070] Energy may be derived from a fluid flow in a host of manners, such as flowing the fluid through a turbine.

[0071] A pump is obtained when the pressure generated by the forced fluid is used for pumping that or another fluid, for example.

[0072] A third aspect of the invention relates to method of operating an actuator comprising a flexible elongated structure, or a hydraulic rope, the structure comprising:

[0073] an elongate, hollow and flexible container having an inlet,

[0074] a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements, and

[0075] Inspicos / 10 / 03 / 2026 / 10:52a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,

[0076] the method comprising operating a fluid feeder comprising a pump configured to feed fluid into and / or out of the elongate, flexible container via the inlet and a fluid conduit to alter a distance between the first and second anchor elements.

[0077] Clearly, the flexible elongated structure may be that of the first aspect, and all embodiments, situations, considerations and the like of the first aspect are equally relevant to this aspect.

[0078] A fourth aspect of the invention relates to a method of operating a sensor comprising a flexible elongated structure, the structure comprising:

[0079] an elongate, hollow and flexible container having an inlet,

[0080] a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements,

[0081] a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,

[0082] the method comprising determining an amount of fluid transported between the flexible container and a fluid feeder, via a fluid conduit and the inlet, when a distance between the first and second anchor elements varies. From the amount of fluid, the distance between first and second anchor may be determined.

[0083] Clearly, the flexible elongated structure may be that of the first aspect, and all embodiments, situations, considerations and the like of the firstand second aspects are equally relevant to this aspect.

[0084] A fifth aspect of the invention relates to a method of operating a sensor comprising a flexible elongated structure, the structure comprising:

[0085] Inspicos / 10 / 03 / 2026 / 10:52an elongate, hollow and flexible container having an inlet,

[0086] a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements,

[0087] preferably a fluid feeder-configured to feed fluid into and receive fluid from the elongate, flexible container via the inlet and a fluid conduit, and

[0088] a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,

[0089] the method comprising determining a pressure of the fluid in the flexible container.

[0090] Clearly, the flexible elongated marine structure may be that of the first aspect, even though the fluid feeder is not required in this aspect of the invention. However, still, all embodiments, situations, considerations and the like of the first and second aspects are equally relevant to this aspect.

[0091] Naturally, the fluid feeder may be provided as in the remaining aspects, so that the structure may also comprise a fluid feeder configured to feed fluid into and receive fluid from the elongate, flexible container via a fluid conduit.

[0092] A sixth aspect of the invention relates to a method of generating power using a flexible elongated structure, the structure comprising:

[0093] an elongate, hollow and flexible container having an inlet,

[0094] a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements, and

[0095] a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,

[0096] Inspicos / 10 / 03 / 2026 / 10:52the method comprising generating power from a flow of fluid between the flexible container and a fluid feeder connected to the flexible container via a fluid conduit and the inlet when a distance between the first and second anchor elements varies.

[0097] Clearly, the flexible elongated marine structure may be that of the first aspect, even though the fluid feeder is not required in this aspect of the invention. However, still, all embodiments, situations, considerations and the like of the first and second aspects are equally relevant to this aspect.

[0098] The fluid feeder may be embodied as the above fluid feeder or it may be a second container according to the above embodied fluid feeder. The second container may be configured to provide a fluid therein with a predetermined pressure or minimum pressure so that fluid may flow therefrom to the flexible container when the distance between the first and second anchoring elements drops. Usually, the second container is a sealed container so that the fluid cannot escape the system.

[0099] A seventh aspect of the invention relates to a mooring system comprising a plurality of submersed flexible elongated structures according to any of preceding embodiments, further comprising:

[0100] • at least one sensor configured to detect displacement of the flexible elongated structure; and

[0101] • a controller unit operatively connected to the pump and configured to:

[0102] o receive displacement data from said at least one sensor, and

[0103] o control the pump to modify an internal volume within a selected flexible elongated container

[0104] Clearly, the flexible elongated marine structure may be that of the first aspect and all embodiments, situations, considerations and the like of the above aspects are equally relevant to this aspect.

[0105] In some embodiments, the controller unit is configured to control internal volume of each of the elongated flexible container separately via the fluid conduit of each of the flexible elongated structure.

[0106] In some embodiment, the method comprises selectively varying an internal volume within the plurality of the elongate flexible containers by controlling the pump and modifying an axial length and tensile force of the respective flexible container.

[0107] Inspicos / 10 / 03 / 2026 / 10:52Displacement of the elongated structure may be caused by sea currents, wave motion, tidal variation, or other movement of seawateracting on the structure. The sensor may comprise one or more of a position sensor, depth sensor, force sensoror pressure sensor. The sensor may be configured to provide displacement data to a control unit operatively connected to a fluid displacement device, such as a pump, in fluid communication with the flexible elongated container disposed within the flexible sleeve.

[0108] The control unit may be configured to receive the displacement data and to control operation of the pump. The pump may be selectively vary the quantity of fluid within the flexible container. By increasing or decreasing the volume of fluid within the container, the internal pressure may be modified, such as may be maintained at a target level. Due to the geometry of the flexible sleeve, modification of internal pressure results in a corresponding change in axial length and / or tensile force of the structure.

[0109] In this manner, the system may be able to actively counteract detected displacement by adjusting the effective length and tension of the structure.

[0110] Moreover, the herein disclosed technology further relates to a system comprising a plurality of hydraulic ropes, attached to a buoyancy structure. The buoyancy structure comprises hollow elongated tube (Buoy-tube) comprising a plurality of water bags within the hollow elongated tube and a first incompressible fluid, e.g. water within the water-bags. The hydraulic ropes may comprise a predefined amount of fluid which may preferably be sealed within the flexible containers. Based on pressure variation within hydraulic ropes, a volume of the water-bags may be adjusted. Clearly, the hydraulic rope may be the flexible elongated structure of the first aspect, and all embodiments, situations, considerations and the like of the any other aspects are equally relevant to this aspect.

[0111] In the following, preferred embodiments will be described with reference to the drawing, wherein:

[0112] Fig. 1 illustrates a structure according to the first aspect of the invention in extended and contracted states,

[0113] Fig. 2 illustrates the extended structure of figure 1 without the weave,

[0114] Fig. 3 illustrates an alternative to the weave of figure 1,

[0115] Fig. 4 illustrates the fluid feeder in greater detail, and

[0116] Fig. 5 illustrates a number of use situations of the structure of the invention, Fig. 6 illustrates pressure sensitivity of a length of the structure for different thread angles and different sleeve diameters,

[0117] Fig. 7 illustrates a balance drive and a buoy-tube

[0118] Inspicos / 10 / 03 / 2026 / 10:52Fig. 8 illustrates an embodiment of a buoy-tube.

[0119] Figure 1 illustrates a flexible elongated structure 10 according to the invention, the structure comprising two anchor elements 12 interconnected by a weave 18 of wires or threads forming a number of helical springs or woven rope, with two different directions of rotation, around a flexible container 14 which may receive fluid from a fluid feeder 20 via a conduit 22.

[0120] The operation of the flexible container 14 and the weave 18 is that when a low amount of fluid is present in the container 14, the weave 18 is allowed to stretch allowing a larger distance between the anchor elements 12 (left illustration), whereas if the amount of fluid in the container 14 is higher, the container 14 will widen in diameter and will thus cause the weave 18 to widen its circumference but shorten in length (right illustration).

[0121] When broadening the weave, the angle, a, between the weave strands and the longitudinal direction, D, of the flexible elongated structure 10 increases. Then, the distance along the longitudinal direction which the strands can make (the strands having a fixed length) becomes lower.

[0122] Thus, by adding or removing fluid from the container 14, the length, L, of the structure may be controlled. Thus, in one situation, a pulling force on the anchor elements 12 may be controlled.

[0123] The fluid controlling the length of the structure is fed from the feeder 20 via a conduit 22 which preferably passes through an anchor element 12. In this manner, the container may be fixed to the anchor element and an opening from the container to the conduit 22 may be inside the anchor element.

[0124] Figure 2 illustrates the flexible elongated structure 10 without the weave 18.

[0125] The container may be made of Thermoplastic Elastomers (TPE), Polyurethane (PU), Latex Rubber, Nitrile Rubber (NBR), EPDM (Ethylene Propylene Diene Monomer) Rubber, Fluoroelastomers (FKM), Polyvinyl Chloride (PVC), Santoprene® (TPV), Styrene -Butadiene Rubber (SBR), silicone, and the like.

[0126] The weave 18 is merely one manner of obtaining a structure which is capable of extending around a flexible core, having a longitudinal direction and widening in circumference perpendicular to the longitudinal direction while contracting along the longitudinal direction. Figure 3 illustrates an alternative structure capable of the same, in the shape of a honeycomb structure.

[0127] Inspicos / 10 / 03 / 2026 / 10:52It is noted that the weave 18, irrespective of how it is implemented or embodied, may have a rest shape, such as that of the elongated state (left illustration of figure 1), so that if the fluid is allowed to flow freely into and out of the container, the sleeve structure will move towards the elongated state. Moving toward the compressed state then is obtained by forcing fluid into the container 14.

[0128] Clearly, a flexible elongated structure 10 as illustrated may be used for a number of purposes. One purpose is obtained when the amount of fluid, and hence inner pressure, in the container 14 is varied, causing a change in the pulling force on anchor elements 12. In this situation, the distance between the anchor elements 12 changes. Then, the flexible elongated structure forms an actuator.

[0129] Alternatively, the feeder 20 may present a predetermined counter pressure against fluid leaving the container 14. In this manner, a flexible sleeve is obtained allowing the distance between the anchor elements 12 to change only if the force is large enough.

[0130] Yet alternatively, a pressure of the fluid in the container 14, the conduit 22 or the feeder 20 may be determined, as this is a measure of any force acting to elongate the flexible elongated structure 10.

[0131] Figure 4 illustrates the fluid feeder20 in further detail. A pump 202 is provided for delivering fluid to or drawing fluid from the conduit 22 and the container 14. This pump 202 may be used to control pressure and flow of fluid as well as the direction of the flow. Valves may also be provided either in the feeder20 for preventing fluid flow into or out of the feederor in the conduit 12 or container 14 for preventing fluid flow therein or into / out of it. Thus, both controlling and sensing is possible.

[0132] Further, a pressure sensor204 may be provided for determining a pressure of the fluid in the conduit 12 or container 14. This pressure is described above.

[0133] Additionally, a flowmeter 206 may be provided for determining the amount of fluid moved into or out of the feeder 20 and / or the container 14.

[0134] Also, the flexible elongated structure may be used for energy harvesting, as a continued elongation and compression of the structure will create a flow of fluid into and out of the container 14. This movement may be used for driving e.g. a turbine 208 or the like for harvesting energy.

[0135] Inspicos / 10 / 03 / 2026 / 10:52In addition thereto, the feeder 20 may comprise a controller 210, communication elements (antenna or the like) 212, battery 214 as well as the storage 216 for the fluid, and the like for supporting the desired operation thereof.

[0136] Figure 5 illustrates a system 30 for growing bivalves and illustrates a number of manners in which the structure of the invention may be used.

[0137] The system 30 comprises a number of culturing lines 36 for seed mussels which over time will grow to be harvested. The culturing lines 36 are maintained at a desired horizontal position by moorings 35 and in a vertical position by e.g. a buoyancy of a buoyancy tube 31, the buoyancy of which may be controlled by a controller 33 altering the buoyancy of the tube 31 by adding or removing a liquid therefrom.

[0138] The Buoy-tube 31 comprises a number of water bags 221 (as shown in figure 8) for controlling a buoyancy of the tube 31. A plurality of water bags 221 are provided along a length of the tube 31.

[0139] In order to not have a longitudinal strain on the tube 31, the culturing lines hang from a long line 37 extended by two buoys 32 attached via lines 38 to the moorings 35. The upwardly directed force by the tube 31 is transmitted to the long line 37 via intermediate lines 39.

[0140] A communication buoy 34 sits on the surface 41 and facilitates the communication of status, sensor readings and the like between the controller 33 and a remote central. The buoy 34 is connected to the mooring via cable 40 and communicates with the controller via cable 341.

[0141] The controller 33, shown in fig. 5, may be a balance drive or alternatively the balance drive 24 (shown in fig. 7) comprises a controller 244. The buoyancy of the tube 31 is controlled by the balance drive 24 comprising a fluid container 241 and a gas container 242 for supplying gas and / or fluid to different parts of the tube 31 for maintaining the buoyancy thereof.

[0142] The balance drive 24 is illustrated in figure 7 and it comprises a container 241 for a first fluid, an optional container 242 for a second fluid and a controlling portion 243 comprising a controller 244 (or 33) and usually also one or more pumps, a battery, a plurality of different valves, a flow meter and the like for performing its desired operation. The balance drive 24 is connected to a flexible container(s) via conduits 25.

[0143] Measuring changes in volume of first fluid in buoytube bags to maintain constant average pressure within each of the hydraulic ropes (which pressure depends on geometry for each rope), is proportional to change in livestock weight. Weight of livestock at beginning of each

[0144] Inspicos / 10 / 03 / 2026 / 10:52cultivation period is known. Summing up changes from initial weight of livestock gives an estimation for weight over time. Movement of first fluid volume is measured using a flow meter.

[0145] The operation of the system 30 generally is that as the culturing lines will be maintained below a desired distance from surface , e.g. below approximately 10 meters depth for bivalves. The cultured organism (e.g. bivalves, seaweed and others) will gain weight over time, so that the buoyancy of the tube 31 must be adapted to take this weight increase into account.

[0146] There may, however, during this growth season be situations where the vertical position of the culturing lines in the body of water is to be altered. Also, it may be desired to know the weight of the culturing lines and / or bivalves during the growth phase.

[0147] Altering a height of the culturing lines in the body of water could be obtained by embodying lines 38 according to the invention. In this situation, the length of the lines 38 may be varied by varying an amount of fluid in the container 14.

[0148] Furthermore, a tension of the lines 38 may be determined when these are embodied as sensors as described above. Then, when combined with knowledge of the buoyancy of the tube 31, a weight of the assembly below the tube (lines 36, 37 and 39) may be determined.

[0149] Furthermore, adjusting the tension of the lines 38 to be a set value of for example 10-50 kgf (kiloforce) upwards, that force will act against current forces in the lateral direction when the longline shifts with lateral currents. This force can then be adjusted as required depending on currents where deployed.

[0150] The tension of the lines 38 may also be indicative of sideways forces such as caused by current in the water.

[0151] Lines 38 may be connected to any portion of the load carrying structure. Allowing the lines 38 to not be vertical has the advantage that a longer length may be provided in more shallow depths allowing a sufficiently large range of operation or sensing. Also, resistance against sideways forces acting along the length of the longline will then be in addition to what the end mooring lines provide, like a small version of float 32 are added along the length of the longline 37.

[0152] As the downwardly directed forces created by the culturing lines 36 are taken up by the intermediate lines 39, implementing lines 39 according to the invention will cause the lines

[0153] Inspicos / 10 / 03 / 2026 / 10:5239 to experience a force acting to stretch the lines 39. Then, when embodying these lines according to the invention, and as mentioned above, this force may be determined from an internal pressure of the fluid in the container 14, whereby this force may be determined. Also, from this, the weight of the produce on the culturing lines 36 may be determined. Clearly, the same types of lines may then be used for allowing the tube 31 to displace vertically independently of the culturing lines 36.

[0154] Yet another manner of using the structure of the invention is as the line 40. The buoy 34 sits on the surface, whereby its height above the bottom 42 will vary with both tides and waves. Embodying this line as the structure of the invention will allow power generation for e.g. powering the operation of the buoy 34 and controller 33. By providing a structure biased toward its compressed state but allowing the structure to extend by allowing fluid to exit the container 14 but passing the water through a turbine, the exiting and entering flow of fluid will drive the turbine and generate power.

[0155] Naturally, irrespective of in how many places the lines are embodied as structures according to the invention, the controller 33, which will already have therein one or more fluid containers, one or more pumps, one or more flow meters, a controller, a battery and the like, for controlling the buoyancy of the tube 31, may be used as the feeder 20, the contents of which could then be provided in the controller 33.

[0156] It is noted that when used submerged, the weight of the structure of the invention need not be high, such as if the fluid used in the container 14 is the same as that of the surrounding water, or if the fluid in the container e.g. was lighter, such as sweet water or fresh water, which is lighter than salt water.

[0157] The feeder20 may comprise a flexible fluid container, such as a flexible bag. Then, this bag and the container 14 would be experiencing the same external pressure, unless they are positioned at very different heights in the body of water, so that the bias ing by the weave 18 toward the compressed state may be sufficient to contract the container 14 by moving the fluid to the feeder 20.

[0158] Pulling force on a hydraulic rope may be calculated using a function

[0159] Force = FPull(Press, Vol, StructOuterSleve, StructlnnerContainer) where Force is the force pulling on a hydraulic rope anchor, Press is the measured pressure at a position within the hydraulic rope, Vol is the volume within the flexible inner container, StructOuterSleve comprises structure parameters that describe the makup of the flexible outer sleeve, e.g.

[0160] Inspicos / 10 / 03 / 2026 / 10:52• Nhelix : number of rounds that the threads make over the length of the hydraulic rope (independent of length or tension)

[0161] • LSIeeveLong: length of sleeve in its longest configuration

[0162] • DSIeeveLong: diameter of sleeve in its longest configuration

[0163] • Nthreads: total number of threads in the hydraulic rope

[0164] • Athreads: average area of a thread

[0165] • YMthreads: Youngs modulus of threads

[0166] and StructlnnerContainer are structure parameters of inner flexible container comprising e.g.

[0167] • IDHose: inner diameter of hose when relaxed

[0168] • ODHose: outer diameter of hose when relaxed

[0169] • LHose: length of hose when relaxed

[0170] • nuHose: Poisson's ratio for hose material

[0171] In order to estimate change in pulling force this function may be applied on Press before and after change of livestock weight.

[0172] Moreover, in order to estimate change in pulling force, a change in pulling force (deltaF) may be calculated as a function of change in pressure within the hydraulic rope (deltaP) for different angles and diameters as shown in Figure 6. Figure 6 illustrates a simplified pressure sensitivity for a structure, which could be seen as a hydraulic rope, according to the invention with a weave of flexible rope strands. The pressure sensitivity is calculated using deltaP = Press2 - Pressl

[0173] deltaF = FPull(Press2, ...) - FPull(Pressl, ...)

[0174] pressure sensitivity = deltaP / deltaF

[0175] Since both the thread angle and weave diameter change when the distance between the anchoring elements changes, the sensitivity of a given structure changes with length also. The values depend on thread properties, weave pattern and the state in which the system is assembled, for example the proportion LHose I LSIeeveLong, or the proportion ODHose I DSIeeveLong.

[0176] The flexible sleeve has a movement range between LSIeeveShort (length of the sleeve at the short, compact extended state, the minimum sleeve length) and LSIeeveLong (length of the sleeve at the long, elongated, extended state) restricted by the weave pattern. At minimum

[0177] Inspicos / 10 / 03 / 2026 / 10:52sleeve length the sleeve has its largest diameter while at LSIeeveLong it has its smallest diameter.

[0178] The flexible container (Hose) in its relaxed state has a length LHose and outer diameter DHose. When assembling the structure, LHose can be chosen to be shorter than LSIeeveLong so that when the structure is LSIeeveLong long, the flexible container is stretched resulting in a contracting force defined by flexible container wall thickness and Youngs Modulus. These sizes can be selected so that the structure either stretches, compresses or folds in both transverse direction and / or along the length of the structure when the structure length changes.

[0179] Inspicos / 10 / 03 / 2026 / 10:52

Claims

23CLAIMS1. A flexible elongated structure (10), the structure comprising:• an elongate, hollow and flexible container (14) having an inlet,• a first and a second anchor element (12), the elongate, flexible container (14) being positioned between the first and second anchor elements (12),• a fluid feeder(20), configuredto feed fluid into and receive fluid from the elongate, flexible container (14) via the inlet and a fluid conduit (22), the fluid feeder comprises a pump configured for feeding fluid into and / or out of the elongate, flexible container (14) via the fluid conduit (22), and• a flexible sleeve (18) attached to the first and second anchor elements (12) and forming an inner space in which the flexible container (14) is provided, the flexible sleeve (18) being configured to reduce a distance between the first and second anchor elements (12) when a volume of fluid in the flexible container (14) and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements (12), increase.

2. A structure (10) according to claim 1, wherein the flexible sleeve comprises a plurality of strands of material each having a helical coil shape around the flexible container, each having a first end connected to the first anchor element and each having a second end connected to the second anchor element.

3. A structure (10) according to claim 2, wherein a maximum distance of 10mm exists from all portions of an outer surface of the flexible container between the first and second anchor elements and to a strand.

4. A structure (10) according to any of the preceding claims, wherein the fluid conduit extends through the first anchor element.

5. A structure (10) according to any of the preceding claims, wherein the fluid feeder further comprises a valve configured to block or allow fluid flow.

6. A structure (10) according to any of the preceding claims, comprising a pressure sensor configured to measure a pressure of the fluid in the flexible container.

7. A structure (10) according to any of the preceding claims, comprising a sensor, such as a flowmeter, configured to measure amount of fluid moved into or out of the fluid feeder and / or the flexible container and / or buoyancy elements attached to the structure.Inspicos / 10 / 03 / 2026 / 10:

528. A structure (10) according to any of the preceding claims, comprising a control unit configured to receive sensor data from the pressure sensor and / or the flowmeter.

9. A structure (10) according to claim 8, wherein the control unit is configured to operate the pump to feed fluid into or out of the elongate, flexible container based on received sensor data representing volume of the fluid within the flexible container.

10. A structure (10) according to claim 9, wherein the control unit is configured to adjust maximum height of a structure above bottom by changing volume within the elongate flexible container.

11. A structure (10) according to any one of the preceding claims, comprising means configured to determine a force exerted by a hydraulic rope based on pressure measured within the elongate flexible container and the volume of fluid within the elongate flexible container.

12. A structure (10) according to any of the preceding claims, wherein one end of the flexible container is attached to and closed by the first anchor element and the other end is attached to and closed by the second anchor element.

13. A structure (10) according to claim 12, wherein the flexible container is formed from a tube and the inlet is into the end of the flexible container engaged by the first anchor element.

14. A structure (10) according to any of the preceding claims wherein the fluid is an incompressible fluid, such as water.

15. A structure (10) according to any of the preceding claims, wherein the flexible container has a biased length shorter than a length of the flexible sleeve in a longer, extended state.

16. A structure (10) according to any of the preceding claims, wherein the flexible container has a biased diameter smaller than an inner diameter of the flexible sleeve in a shorter, compact state.

17. A structure (10) according to any of the preceding claims, wherein the flexible sleeve is biased toward a state in which little or no fluid is present in the flexible container.Inspicos / 10 / 03 / 2026 / 10:5218. A structure (10) according to any of the preceding claims, wherein the flexible sleeve is biased toward a state in which a distance between the first and second anchor elements is below a threshold distance, such as to a minimum distance.

19. A sensor comprising a structure according to any of the preceding claims, further comprising means for quantifying an amount of fluid entering and / or exiting the flexible container.

20. A sensor comprising a structure according to any of the preceding claims, further comprising means for quantifying a pressure of the fluid in the flexible container.

21. A power generator comprising a structure according to any of the preceding claims, further comprising means for deriving energy from a flow of fluid into and / or out of the flexible container.

22. A method of operating an actuator comprising a flexible elongated structure, the structure comprising:• an elongate, hollow and flexible container having an inlet,• a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements, and• a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,the method comprising operating a fluid feeder comprising a pump configured to feed fluid into and / or out of the elongate, flexible container via the inlet and a fluid conduit to alter a distance between the first and second anchor elements.

23. A method of operating a sensor comprising a flexible elongated structure, the structure comprising:• an elongate, hollow and flexible container having an inlet,• a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements,• a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve beingInspicos / 10 / 03 / 2026 / 10:5226configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,the method comprising determining an amount of fluid transported between the flexible container and a fluid feeder, via a fluid conduit and the inlet, when a distance between the first and second anchor elements varies.

24. A method of operating a sensor comprising a flexible elongated structure, the structure comprising:• an elongate, hollow and flexible container having an inlet,• a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements,• a fluid feeder-configured to feed fluid into and receive fluid from the elongate, flexible container via the inlet and a fluid conduit, and• a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,the method comprising determining a pressure of the fluid in the flexible container.

25. A method of generating power using a flexible elongated structure, the structure comprising:• an elongate, hollow and flexible container having an inlet,• a first and a second anchor element, the elongate, flexible container being positioned between the first and second anchor elements, and• a flexible sleeve attached to the first and second anchor elements and forming an inner space in which the flexible container is provided, the flexible sleeve being configured to reduce a distance between the first and second anchor elements when a volume of fluid in the flexible container and a cross sectional area in a plane perpendicular to an axis through the first and second anchor elements, increase,the method comprising generating power from a flow of fluid between the flexible container and a fluid feeder connected to the flexible container via a fluid conduit and the inlet when a distance between the first and second anchor elements varies.Inspicos / 10 / 03 / 2026 / 10:522726. The method according to any one of claims 22-25, wherein the flexible elongated structure is according to any one of claims 1-18.

27. A mooring system comprising a plurality of submersed flexible elongated structures according to any one of claims 1-18, further comprising:• at least one sensor configured to detect displacement of the flexible elongated structure; and• a controller unit operatively connected to the pump and configured to:o receive displacement data from said at least one sensor, ando control the pump to modify an internal volume within a selected flexible elongated container.

28. A mooring system according to claim 27, wherein the controller unit is configured to control internal volume of each of the elongated flexible container separately via the fluid conduit of each of the flexible elongated structure.

29. A method of operating a system according to claims 27-28, comprising the steps of:• selectively varying an internal volume within the plurality of the elongate flexible containers by controlling the pump;• modifying an axial length and tensile force of the respective flexible container.Inspicos / 10 / 03 / 2026 / 10:52

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