WO2018197510A1

WO2018197510A1 - Barrier structure assembly and method of construction

Info

Publication number: WO2018197510A1
Application number: PCT/EP2018/060499
Authority: WO
Inventors: Michele Grassi
Original assignee: Elements Works Srl
Priority date: 2017-04-24
Filing date: 2018-04-24
Publication date: 2018-11-01
Also published as: GB201706454D0

Abstract

A barrier structure assembly (10) for use underwater, the assembly comprising a barrier screen (15) and a set of upper floats (17), which, in use, are connected to an upper edge of the barrier screen, a set of lower anchoring elements (20), which, in use, are connected to a lower edge of the barrier screen, a set of intermediate floats (19), which, in use, are connected to a first fold-line of the barrier screen between the set of upper floats and the set of lower anchoring elements. A first lower portion (22) of the barrier screen (15) extends between the set of lower anchoring elements (20) and the set of intermediate floats (19). The assembly also includes a set of intermediate weights (18), which, in use, are connected to a second fold-line of the barrier screen between the set of intermediate floats (19) and the set of upper floats (17). A second middle portion (23) of the barrier screen is provided between the set of intermediate weights (18)and the set of intermediate floats (19), and a third upper portion (24) of the barrier screen extends between the set of the intermediate weights and the set of upper floats.

Description

BARRIER STRUCTURE ASSEMBLY AND METHOD OF CONSTRUCTION

FIELD OF THE INVENTION

[0001] The present application relates to a barrier structure assembly. The present application relates to a barrier for underwater use whose height can be changed for example to accommodate for changes in the depth of the water. Embodiments of the invention are especially advantageous when used near a shoreline as a barrier to sharks or jellyfish although the invention is also applicable in other locations and as a barrier to other species such as algae. Embodiments of the invention are also suitable for use as fish pens used in, for example, fish farming. Further embodiments of the invention may be used to disrupt or deflect water currents in locations prone to coastal erosion.

BACKGROUND OF THE INVENTION

[0002] Underwater barriers are needed or desired in various situations for separating two bodies of water and controlling the passage of species between the two. Jellyfish and other so- called ocean stingers are common examples of such species. Jellyfish invasion of beaches is a problem in parts of the world. An incursion of jellyfish into the shallow waters of beaches can put a halt to all bathing and swimming, in turn reducing the presence of people on the beach. Besides causing significant problems for vacationers and the like, the economic activities of local business such as bars, hotels, restaurants, etc., can be severely affected.

[0003] This has led to the development of so-called jellyfish nets, which create a physical barrier between people and jellyfish. The jellyfish net forms a path through a body of water, separating water on one side of this path from water on the other side of the path, and isolating an inner body of water. The jellyfish net comprises a net which spans the entire depth of the water; the top of the net being held at the surface of the water by a set of floaters, and the bottom of the net being held to the ground beneath the water via an anchoring system. The anchoring system comprises either a set of weights or a set of fixings to the ground beneath.

[0004] Jellyfish nets often employ a 'taut net' arrangement. In this arrangement, the net is held taut between the floaters and the weights or fixing points such that the net is effectively fixed in place. CN102730170 discloses a method for constructing a jellyfish net which uses the taut net arrangement. The jellyfish net of CN102730170 is constructed next to a shoreline, isolating an rectangular area of water, as viewed from above, from the surrounding waters. The net is intended to block sharks, jellyfish, and the like, to render the area safe for swimming.

[0005] The taut net arrangement, of CN102730170 for example, suffers several limitations. In order to hold the net taut throughout, the dimensions of the net as well as the points of connection to the anchoring apparatus must be chosen carefully so as to avoid any loose sections of net. This requires that, prior to installation, the depth of the water is measured at each point above which the net will be positioned. Specialized equipment will likely be needed to obtain this information. Furthermore, installation of such a barrier almost invariably requires the intervention of specialized personnel and, in most cases, also scuba divers. As a result, the design and installation stages are complicated and expensive. In addition, they prevent the possibility of a purely online business model for the production and distribution of such a barrier, since specialized personnel will need to be supplied for installation together with the hardware. In addition, the expense associated with the installation will often make it infeasible to use the barrier on a temporary basis. A further limitation is that, due to the taut and inextensible nature of the arrangement, an increase in the water depth, due to waves or tides, can submerge the upper edge of the net, creating an access route for jellyfish. On the other hand, an increase in the water depth could cause the surface floaters to lift the weights of the anchoring system from the floor.

[0006] So-called shark nets are often similar to jellyfish nets but have a sturdier nature. The net in this case will be stronger and so typically heavier, in turn requiring larger surface floaters and stronger anchoring systems. A taut net arrangement is often used for shark nets too, and suffers the same previously identified limitations.

[0007] A more practical barrier arrangement is desirable. One alternative option is to erect a fully-rigid fence in the water, with a height equal to a maximum anticipated depth of water. This would result in an upper section of the fence protruding above the surface of the water, which is undesirable for many reasons. Aside from the visual impact, such an arrangement is unsuitable because it does not allow for passage across the fence. In touristic beach scenarios, it may, for example, be necessary to allow passage of lifeboats across the fence.

[0008] Another alternative arrangement is a variable-height barrier. The variable -height barrier is similar to the taut net arrangement, except the net is slack, at least in a vertical direction, such that the surface floaters are free to rise and fall with the surface of the water whilst the anchoring apparatus remain at the bottom of the water. The 'net' used in a variable- height barrier may be a conventional net comprising fibres woven in a grid-like structure or, alternatively, the net may have a different nature, comprising for example rigid plates joined using hinges.

[0009] Jellyfish and shark nets often make use of the variable -height barrier arrangement, however the variable -height barrier would be equally useful in many more scenarios. In fisheries, for example, a variable -height barrier would be suitable for containing fish being reared in tidal waters. In another use, a variable -height barrier may be employed nearby a touristic beach where it is required to screen dead algae from the surrounding waters which would otherwise engulf the beach. In yet another use, the variable -height barrier could be used to surround waters used by surfers, screening aggressive animals whilst allowing waves to pass through the barrier towards the surfers. In a different scenario, the variable -height barrier can be suitable for disrupting water currents, such as ocean currents or storm-induced currents, with the aim of reducing coastal erosion. Whilst reducing coastal erosion in this manner, the barrier may still allow waves to pass through, thereby limiting the impact on the geophysical equilibrium of the coast.

[0010] Variable -height barriers can take several forms. FR3025777 discloses one such arrangement, making use of a square mesh 'net'. In this case, the bottom of the net is held to the ground below via anchors, whilst the net itself is made from buoyant material such that no surface floaters are needed.

[0011] There are several issues with the net of FR3025777, which are also issues common to typical variable -height barriers in general. In order to operate effectively in water with a changing depth, due to waves and tides, the net must have enough slack to be able to expand to the maximum anticipated depth of the water. In scenarios where the depth of the water changes significantly, there will be a significant amount of slack net material when the depth of water approaches its minimum value. This slack material gives rise to several issues. For one, the excess material is prone to rubbing on the ground beneath the water which could incur damage to the material. Limitations are therefore placed on the types of materials that the net can be constructed from. In addition, the excess material can accumulate nearer to the surface of the water, where it is liable to entangle with surface structures, animals or, worse, with divers.

[0012] An alternative form of a variable -height barrier is disclosed in EP3003851. In this example, the 'net' comprises a fine mesh structure and the net is sectioned between rigid vertical columns. The net is attached to the columns via connectors which can move vertically along the column, thereby allowing for vertical movement of the net. WO2015127493 discloses a similar barrier to that of EP3003851 , however instead of a fine mesh structure, the net is semi-rigid and folds in a concertina-like manner.

[0013] The incorporation of columns into barrier apparatus introduces several problems. For one, installation of the barrier is a much harder task. The columns must be carefully positioned and oriented to be parallel. This is especially important for WO2015127493 since if these requirements are not met the folding net may break and or no longer be able to slide along the columns effectively. Installation may therefore require large marine systems like barges, and almost invariably requires the intervention of specialized personnel and, in most cases, also scuba divers. As a result, the design and installation stages are complicated and expensive. In addition, they prevent the possibility of a purely online business model for the production and distribution of such a barrier, since specialized personnel will need to be supplied for installation together with the hardware. In addition, the expense associated with the installation will often make it infeasible to use the barrier on a temporary basis. Furthermore, the depth of the water must be precisely known at each point along the path over which the barrier will be deployed. This requires inspection with specialized equipment. If the depth is non-uniform along this path, the columns and or net may require a custom cut. In addition, the more complex mechanical nature of the barriers comprising columns leaves them susceptible to mechanical wear. The repetitive vertical motion of the net in the presence of waves or tides will be liable to wear down many of the mechanical parts, in particular the sliding connectors between the net and columns, as well as the hinges and other joints of the net itself. Besides mechanical wear, the inclusion of so many moving parts, especially in the case of WO2015127493, makes the barrier prone to failure, be it due to faulty manufacture or foreign waterborne bodies interfering with the joints. Furthermore, the columns of the barriers will always be in view above the surface of the water, even more so when the tide is low, which incurs a damaging visual impact. [0014] US 2015/0321737 belongs to a separate class of variable height barriers, whereby an array of upstanding (i.e. vertically extending) elongate members is used to deter sharks despite the gaps between the elongate members being large enough for a shark to swim through. The elongate members span the full height of the water and can be articulated such that their height varies to match that of the water. Buoyant material is used to keep the elongate members extended vertically. The elongate members may also comprise magnets. Magnets can over- stimulate certain sharks' electro-sensory systems and so have been found to deter certain shark species. One main limitation of such an arrangement is that, since there is enough space for sharks to swim through the barrier, there is less assurance that sharks will be blocked by the barrier. Furthermore, the barrier is not necessarily suitable for deterring marine species other than sharks.

[0015] Thus, there remains a need for an underwater barrier which overcomes one or more of various above-identified problems present in the prior art.

SUMMARY OF INVENTION

[0016] The present invention in a first aspect provides a barrier structure assembly as disclosed in claim 1 to which reference should now be made. An advantage of the barrier structure assembly is that it offers a variable height without significant risk of mechanical wear, since extension and contraction of the barrier doesn't involve rubbing surfaces or hinges or the like.

[0017] In addition, the barrier structure assembly affords a substantial degree of flexibility in the sense that the first lower second middle and third upper portions of a barrier are able to move relative to each other. This has the advantage that if a shark or other large marine creature were to swim into the barrier, the barrier would oppose the shark with a less firm initial reaction, being able to deform to some extent to accommodate for the shark. This is beneficial on several levels. Firstly, the less firm initial reaction reduces the likelihood of shark entanglement as well as the likelihood of damage to the barrier. Secondly, the less firm initial reaction is beneficial since it reduces the chance of the lower anchoring elements being lifted from the ground below during the collision. If the lower anchoring elements were lifted from the ground, harmful marine creatures such as sharks could pass through the resultant gap.

[0018] Preferably, the assembly further comprises at least one tensioning apparatus for connecting the assembly to at least one support, wherein each support may be above or below the surface of the water.

[0019] Preferably, the support, or one of the supports, is the ground. Alternatively, the support, or one of the supports, comprises a winch and or fixing to the ground. Usefully, incorporation of a winch makes it simple to adjust the tension applied to the barrier structure assembly, both during and after installation of the assembly.

[0020] Preferably, the, or one of the, tensioning apparatus comprises a tension line and a float, the tension line for connecting the upper edge of the barrier screen to the support, or one of the supports, and the float for connecting to the tension line at a point between the upper edge and the support, or one of the supports.

[0021] Preferably, the, or one of the, tensioning apparatus comprises a tension line and a float, the tension line for connecting the first fold-line of the barrier screen to the support, or one of the supports, and the float for connecting to the tension line at a point between the first fold- line and the support, or one of the supports.

[0022] Preferably, in use the assembly is near to a shoreline and forms a barrier across the body of water as viewed from above, such that the assembly separates water on one side of this barrier from water on the other side of the barrier, and wherein each end of this barrier is fixed to land or a shore by one of the tensioning apparatus such that the assembly separates a first body of water from a second body of water. Such a barrier structure assembly will be able to isolate the first body of water from the second body, such that species in the second body of water can only pass to the first body of water if they can pass through the barrier. In this manner, the barrier is able to control the type of species present in the first body of water.

[0023] Preferably, the assembly forms a substantially three-sided barrier through the body of water as viewed from above, having two vertices, one vertex at each of the two points where the sides of the barrier meet one another, and wherein at each of the two vertices one of the tensioning apparatus connects to the barrier. [0024] Preferably, the tensioning apparatus connected to each of the vertices of the barrier apply tension to both sides of the barrier that meet at the vertex by applying a tension which is directed, as viewed from above, to have a first resolved component parallel to one of the sides and a second resolved component parallel to the remaining side. In conjunction with this, the tensioning apparatus may be installed such that tension in tension lines connecting to the first fold-line of the assembly is greater than tension in tension lines connecting to the upper edge. In this arrangement, the tensioning apparatus may keep the first fold-line horizontally separated from the upper edge at all points along the barrier. As a result, the first fold-line may be horizontally separated from the second fold-line at all point along these fold-lines, which is desirable in order to avoid entanglement of these two fold-lines during expansion and contraction of the barrier.

[0025] Preferably, in use, the set of upper floats is arranged to float on or near the surface of the body of water. When this is the case, the barrier structure assembly design is such that it is able to rapidly extend and contract so that the set of upper floats always remain at the surface of the water.

[0026] Preferably, in use, the set of lower anchoring elements is arranged to lie on or near the ground beneath the water. Usefully, the barrier structure assembly allows for local variations in the extension of the barrier; that is, if the barrier is used in a position where the depth of the water varies across the width of the barrier, for example due to an uneven ground beneath the water, the set of upper floats can still remain at the surface of the water whilst the set of lower anchoring elements remain at the ground beneath the water.

[0027] The ability of the barrier structure assembly to allow for local variations in extension means that the assembly can be installed in a new location with only an approximate knowledge of the water depth in the new location. An approximate knowledge of the water depth in the new location is sufficient because the barrier will be able to accommodate for changes of height resulting from the uncertainty in this approximation. For many barriers in the prior art, scuba divers or specialized equipment are needed to obtain a detailed knowledge of the water depth in a location before the barrier can be designed and installed in that location. In contrast, with the barrier according to the present invention there is not an essential need for such specialized personnel. As a result, the design and installation stages are significantly less complicated and expensive. In addition, this creates the possibility of distance sale of the barrier, which would allow for a change in the business model of the sector which currently relies on a case by case handling of clients. The ease of installation also makes it feasible to use the barrier on a temporary, for example seasonal, basis.

[0028] Preferably, no sets of floats or weights are attached to the barrier screen in between the set of intermediate weights and the set of intermediate floats such that, when the assembly is in use, the second middle portion of the barrier screen hangs between the set of intermediate weights and the set of intermediate floats. Alternatively, additional sets of floats and weights may be attached to the barrier screen in between the set of intermediate floats and the set of intermediate weights, such that the second middle portion of the barrier screen, when the assembly is in use, assumes a folded configuration.

[0029] Preferably: (i) the set of upper floats has a buoyancy which is greater in magnitude than the resultant weight, when the assembly is in use, of the second middle and third upper portions of the barrier screen and the set of intermediate weights, wherein the resultant weight is the weight less the buoyancy less any upward tensile forces exerted by tensioning apparatus; (ii) the set of lower anchoring elements is able to exert a force on the barrier screen which is greater in magnitude than the resultant buoyancy, when the assembly is in use, of the barrier assembly, wherein the resultant buoyancy is the buoyancy, less the weight, plus any upward tensile forces exerted by tensioning apparatus; (iii) the set of intermediate floats has a buoyancy which is greater in magnitude than the resultant weight, when the assembly is in use, of the first lower and second middle portions of the barrier screen and the set of intermediate weights, wherein the resultant weight is the weight less the buoyancy less any upward tensile forces exerted by tensioning apparatus.

[0030] The advantage of choosing the sets of floats, weights and lower anchoring elements in this manner is that it will ensure that, despite the changing height of the water, the first lower and third upper portions of the barrier screen remain taut, whilst the set of upper floats remains at the surface of the water and the set of lower anchoring elements remains at the ground beneath the water.

[0031] Preferably, the barrier screen comprises a material with holes, such as a net or mesh, which is suitable for filtering out solid species in water. Usefully, this allows for controlling the maximum size of the solid species which are allowed to pass through the barrier. For example, the holes can be chosen small enough to block dead algae suspended in the water. Alternatively, the barrier screen comprises material suitable for filtering out liquid species from water. [0032] In any case, the barrier screen may comprise rigid plates which are connected using hinges. An advantage of this is that a barrier structure assembly using rigid plates may be able to withstand greater forces incident on the assembly. For example, the assembly may be less likely to break in the case that a shark swims into the barrier. In addition, the rigid plates may offer greater resistance to water currents incident on the barrier, which may be desirable in applications aimed at disrupting water currents.

[0033] The present invention also provides a method for installing a barrier structure assembly as disclosed in claim 18 to which reference should now be made. Usefully, the method of installation of the barrier structure assembly is such that it is tolerant to misplacement of the lower anchoring elements and or tensioning apparatus. This has the advantage that installation of the assembly is simpler, such that specialized personnel such as scuba divers are not necessarily required in order to construct and install the assembly.

[0034] Preferably, the method further comprises using tension lines to connect the assembly to at least one support, wherein each support may be the ground and may be above or below the surface of the water. Preferably, a point along the upper edge of the barrier screen is connected to the support, or one of the supports. Preferably, a point along the first fold-line of the barrier screen is connected to the support, or one of the supports.

[0035] Preferably, the method further comprises using the assembly near to a shoreline and arranging the assembly such that it forms a barrier across the body of water as viewed from above, such that the assembly separates water on one side of this barrier from water on the other side of the barrier, fixing each end of this barrier to land or a shore such that the assembly separates a first body of water from a second body of water.

[0036] Preferably, the method further comprises arranging the assembly into a substantially three-sided barrier through the body of water as viewed from above, having two vertices, one vertex at each of the two points where the sides of the barrier meet one another, by connecting each of the two vertices of the barrier to one of the supports. Preferably, at each of the vertices of the barrier, a connection to one of the supports is arranged which applies tension to both sides of the barrier that meet at the vertex by applying a tension which is directed, as viewed from above, to have a first resolved component parallel to one of the sides and a second resolved component parallel to the remaining side.

[0037] Preferably, the set of upper floats is arranged to float on or near the surface of the body of water. Also preferably, the set of lower anchoring elements is arranged to lie on or near the ground beneath the water.

[0038] Preferably, no sets of floats or weights are attached to the barrier screen in between the set of intermediate weights and the set of intermediate floats such that the second middle portion of the barrier screen hangs between the set of intermediate weights and the set of intermediate floats. Alternatively, the method further comprises attaching additional sets of floats and weights to the barrier screen in between the set of intermediate floats and the set of intermediate weights, such that the second middle portion of the barrier screen assumes a folded configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described by way of non-limiting examples with reference to the accompanying figures in which like numerals represent like components and in which:

[0039] Figure 1 is a schematic view of a shoreline at low tide with a barrier structure assembly embodying the invention;

[0040] Figure 2 is a top view of the barrier structure assembly of Figure 1 ;

[0041] Figure 3 is a schematic view of a shoreline at mid tide with the barrier structure assembly of Figure 1 ;

[0042] Figure 4 is a schematic view of a shoreline at high tide with the barrier structure assembly of Figure 1 ;

[0043] Figure 5a is a view along direction 'Bl ' illustrated on Figure 1 of a central section of the barrier structure assembly of Figure 1 ; [0044] Figure 5b is a cross-sectional view of surface 'CI ' illustrated on Figure 1 of a central section of the barrier structure assembly of Figure 1 ;

[0045] Figure 6a is a view along direction 'B2' illustrated on Figure 3 of a central section of the barrier structure assembly of Figure 3;

[0046] Figure 6b is a cross-sectional view of surface 'C2' illustrated on Figure 3 of a central section of the barrier structure assembly of Figure 3;

[0047] Figure 7a is a view along direction 'B3' illustrated on Figure 4 of a central section of the barrier structure assembly of Figure 4;

[0048] Figure 7b is a cross-sectional view of surface 'C3' illustrated on Figure 4 of a central section of the barrier structure assembly of Figure 4;

[0049] Figure 8 is a schematic illustration of the barrier structure assembly of Figure 1 in absence of any tensioning apparatus and with all folds of barrier screen opened outwards such that the barrier screen is substantially fiat;

[0050] Figure 9 is a schematic view of a section of the barrier structure assembly of

Figure 1 marked as 'A' on Figure 1 ;

[0051] Figure 10 is a schematic view of an alternative embodiment of the section of the barrier structure assembly of Figure 1 marked as 'A' on Figure 1 ;

[0052] Figure 1 1 is a schematic view of a curved shoreline with a barrier structure

assembly embodying the invention;

[0053] Figure 12 is a schematic view of a land-type tensioning apparatus of the barrier structure assembly of Figure 11 ;

[0054] Figure 13 is a schematic view of an enclosed barrier structure assembly

embodying the invention in a body of open water.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0055] Referring to Figure 1 , the barrier structure assembly 10 isolates a first body of water 12 from a second body of water 13. The barrier structure assembly 10 comprises a folded barrier screen 15 which is attached to a set of upper floats 17, a set of intermediate weights 18, a set of intermediate floats 19 and a set of lower anchoring elements 20.

[0056] The set of upper floats 17 lies on the surface of the water whilst the set of lower anchoring elements 20 lies on the ground beneath the water. A first lower portion 22 of the barrier screen 15 extends between the set of lower anchoring elements 20 and the set of intermediate floats 19. The set of intermediate floats 19 has enough buoyancy to keep the first lower portion 22 of the barrier screen 15 in tension but not enough buoyancy to lift the lower anchoring elements 20 from the ground beneath the water. A third upper portion 24 of the barrier screen 15 extends between the set of intermediate weights 18 and the set of upper floats 17. The set of intermediate weights 18 has enough weight to keep the third upper portion 24 of the barrier screen 15 in tension but not enough weight to pull the upper floats 17 below the surface of the water. A second middle portion 23 of the barrier screen 15 extends between the set of intermediate weights 18 and the set of intermediate floats 19.

[0057] Referring to Figure 2, when looking from above the barrier structure assembly 10 is substantially three-sided, having one portion 30 parallel to the shoreline and two portions 31 , 32 perpendicular to the shoreline. The barrier is held in this three-sided shape by means of land- type 34, 35 and water-type 37, 38 tensioning apparatus. At each of the two vertices of the barrier structure assembly 10 where the parallel portion 30 meets the perpendicular portions 31, 32, water-type tensioning apparatus 37, 38 pull the barrier outwards approximately perpendicularly to each other and at an angle of approximately 45 degrees away from the shoreline. Angles other than 45 degrees may be chosen, provided that each water-type tensioning apparatus 37, 38 still applies tension to both portions that meet at the vertex, due to applying a tension which is directed, as viewed from above, to have a first resolved component parallel to one of the sides and a second resolved component parallel to the remaining side. At each end of the barrier structure assembly 10, where the barrier meets the shore, land-type tensioning apparatus 34, 35 connect the barrier to an inland location. The shoreline is assumed to be linear for ease of description of the barrier structure assembly 10, but this is not a requirement. Where the shoreline is non-linear, the "perpendicular portions" 31, 32 of the barrier structure assembly 10 may not meet the shoreline at an angle of 90 degrees, and the "parallel portion" 30 may not be substantially parallel to the shoreline. However, the "perpendicular portions" 31 , 32 of the barrier structure assembly 10 will remain approximately parallel to one another and approximately perpendicular with respect to the parallel portion 30. Furthermore, the water-type tensioning apparatus 37, 38 will remain applying tension directed approximately perpendicularly to each other and approximately 135 degrees away from the adjacent sides of the barrier structure assembly 10.

[0058] Returning to Figure 1 , the barrier structure assembly 10 is depicted in a contracted configuration, whereby the set of intermediate weights 18 are at a lower height than the set of intermediate floats 19. If the depth of water increases, the set of upper floats 17 will rise accordingly, bringing with them the set of intermediate weights 18. The set of lower anchoring elements 20 and the set of intermediate floats 19 remain at the same height throughout. The barrier structure assembly 10 therefore extends vertically and is able to reach a configuration, depicted in Figure 3, in which the set of intermediate weights 18 are at a similar height to the set of intermediate floats 19. If the depth of water increases further, the set of intermediate weights 18 can rise to a height above the set of intermediate floats 19, as depicted in Figure 4. Starting from Figure 4, if the depth of water decreases, the process is reversed and the barrier structure assembly 10 can return to the configuration of Figure 3 and subsequently that of Figure 1. In this manner, the barrier structure assembly 10 is able to respond to changes in the depth of the water. The barrier structure assembly 10 is able to accommodate for both slow variations in depth, for example due to tides, and rapid variations in depth, for example due to waves.

[0059] Figure 5 depicts the portion 30 of the barrier structure assembly 10 of Figure 1 which is parallel to the shoreline. Figure 5a depicts a view of this portion 30 from the shoreline (illustrated on Figure 1 as Bl) whilst Figure 5b depicts a cross-sectional view of the portion 30 (illustrated on Figure 1 as CI). Figures 6a and 6b depict views equivalent to 5a and 5b but for the barrier configuration of Figure 3 in which the depth of water is greater. Similarly, Figures 7a and 7b depict views equivalent to 5a and 5b but for the barrier configuration of Figure 4 in which the depth of water is still greater.

[0060] Comparing Figures 5a, 6a, and 7a, the difference in height between the set of upper floats 17 and the set of intermediate weights 18 is substantially unchanged in each case. Similarly, the difference in height between the set of intermediate floats 19 and the set of lower anchoring elements 20 is substantially unchanged. Further still, the height of the set of intermediate floats 19 is substantially unchanged in each configuration. However, the height of the set of upper floats 17 moves with the surface of the water and therefore the height of the set of intermediate weights 18 follows accordingly. In Figure 5a, the set of intermediate floats 19 is at a greater height than the set of intermediate weights 18. As the depth of water increases, the set of intermediate weights 18 rises to match the height of the set of intermediate weights 18 (see Figure 6a) and subsequently rises above the height of the set of intermediate weights 18 (see Figure 7 a).

[0061] The dimensions of the parallel portion 30 of the barrier structure assembly 10 are chosen such that at the lowest anticipated depth of water, there will still be a gap between the intermediate weights 18 attached to the parallel portion 30 and the ground beneath the barrier. In contrast, where the perpendicular portions 31 , 32 of the barrier structure assembly 10 meet the shore, the intermediate weights may be touching the ground. In addition, the dimensions of the barrier structure assembly 10 are chosen such that at the largest anticipated depth of water, the set of upper floats 17 are still at the surface of the water (rather than being submerged, which could occur if the water depth exceeded the maximum height of the barrier). In order to calculate the required barrier dimensions as described here, an approximate knowledge of the range of water depths is necessary. In an alternative embodiment, the barrier design may be such that the intermediate weights attached to the parallel portion touch the ground when the water approaches its lowest anticipated depth.

[0062] Referring to Figures 5b, 6b and 7b, the barrier structure assembly 10 has a staggered nature in which the set of lower anchoring elements 20 is nearest to the second body of water 13. Moving inwards, towards the first body of water 12, the set of intermediate floats 19 is next, followed by the set of intermediate weights 18 and finally the set of upper floats 17. As further discussed below, the sets of weights 18 and floats 17, 19 are maintained in this order by the water-type tensioning apparatus 37, 38. This order is also maintained for the two portions 31, 32 of the barrier structure assembly 10 perpendicular to the shoreline. Keeping the sets of weights 18 and floats 17, 19 in this order avoids the sets interfering or entangling with one another. An alternative embodiment is considered in which both the first lower portion 22 and the third upper portion 24 are substantially vertical and still staggered such that the first lower portion is nearer to the second body of water 13 than the third upper portion 24. A further, still staggered, embodiment could also be chosen, in which the set of lower anchoring elements 20 is farthest from the second body of water 13 and the set of upper floats 17 is the nearest to the second body of water 13. In any embodiment, it is essential that the set of intermediate weights 18 is staggered, i.e. displaced horizontally, relative to the set of intermediate floats 19 across the entire span of these sets. This is to ensure that the set of intermediate weights 18 and the set of intermediate floats 19 do not contact one another during contraction and expansion of the barrier structure assembly 10, potentially causing entanglement.

[0063] Whilst Figures 5 to 7 only depict the portion 30 of the barrier structure assembly

10 parallel to the shore, the two remaining portions 31, 32 perpendicular to the shoreline behave in a similar manner. The main difference is that these two perpendicular portions 31, 32 are also subject to a gradual increase in water depth while moving away from the shoreline.

[0064] Figures 1 to 7 depict the barrier structure assembly 10 changing its height in a uniform manner. On top of this uniform height adaptation, the barrier structure assembly 10 is able to locally adapt its height so as to accommodate for local variations in depth. Consider, for example, the portion 30 of the barrier structure assembly 10 in Figure 1 which is parallel to the shoreline. If the depth of water is variable along this portion 30, the portion is able to assume a more contracted configuration at positions of a lesser water depth and a more extended configuration at positions of a greater water depth. This is equally true for the two portions 31 , 32 of the barrier structure assembly 10 in Figure 1 which are perpendicular to the shoreline. If, on top of the uniformly increasing water depth along these two portions 31, 32, there are local variations in depth, these portions are able to adapt in an analogous manner. Such variable water depth can be due to non-uniform wave patterns or due to a non-uniform ground beneath the water. Indeed, it is likely that the ground beneath the water will comprise of peaks and troughs rather than a flat surface uniformly sloping away from the shore.

[0065] The ability of the barrier structure assembly 10 to locally adapt its height means that a barrier according to the present invention can be designed and manufactured for use in a new location, and subsequently installed, without requiring a detailed knowledge of the water depth in that location. An approximate knowledge of the water depth in the new location is sufficient because the barrier will be able to accommodate for changes of height resulting from the uncertainty in this approximation. For many barriers in the prior art, scuba divers or specialized equipment are needed to obtain a detailed knowledge of the water depth in a location before the barrier can be designed and installed in that location. In contrast, with the barrier according to the present invention there is not an essential need for such specialized personnel. As a result, the design and installation stages are significantly less complicated and expensive. In addition, this creates the possibility of distance sale of the barrier, which would allow for a change in the business model of the sector which currently relies on a case by case handling of clients. The ease of installation also makes it feasible to use the barrier on a temporary, for example seasonal, basis.

[0066] In an alternative embodiment, the barrier structure assembly 10 of Figure 1 will be adapted such that the set of upper floats lies beneath the surface of the water. In this embodiment, a gap will exist between the set of upper floats and the surface of the water, whilst the set of lower anchoring elements keeps the barrier anchored to the ground. This could be achieved by designing a barrier such that the maximum barrier height is less than the depth of water. Alternatively, this could be achieved by careful design of the forces acting on the set of upper floats in relation to the buoyancy of the set of upper floats itself. For example, as the depth of water increases, the set of intermediate weights will rise relative to the set of intermediate floats. As a result, the set of intermediate floats support a lesser component of the weight of the set of intermediate weights and the set of upper floats support a greater component of the weight of the set of intermediate weights. In the embodiment of Figure 1, the buoyancy of the set of upper floats is great enough that it will remain at the surface of the water for all barrier configurations. In the presently discussed alternative embodiment, the buoyancy of the set of upper floats may be chosen such that it is not sufficient to support the component of the weight of the set of intermediate weights when the depth of water exceeds a certain value, causing the set of upper floats to be submerged. An alternative manner in which the set of upper floats is kept beneath the surface of the water is by use of active land-type and or active water-type tensioning apparatus, as discussed later, or by use of floats or weights of variable buoyancy. Such a gap, between the surface of the water and the set of upper floats, which could be created only temporarily, could be useful to allow passage of vessels such as lifeboats over the barrier or for other purposes.

[0067] In a further alternative embodiment, the barrier structure assembly 10 of Figure 1 will be adapted such that the set of lower anchoring elements lies above the ground beneath the water. In this embodiment, a gap will exist between the set of lower anchoring elements and the ground beneath the water, whilst the set of upper floats supports the entire weight of the barrier. This could be achieved by designing a barrier such that the maximum barrier height is less than the depth of water. Alternatively, this could be achieved by careful design of the forces acting on the set of lower anchoring elements in relation to the weight of the set of lower anchoring elements itself. For example, as the depth of water increases, the set of intermediate weights will rise relative to the set of intermediate floats. As a result, the set of intermediate floats support a lesser component of the weight of the set of intermediate weights and the set of lower anchoring elements experience a greater component of the buoyancy of the set of intermediate floats. In the embodiment of Figure 1 , the weight of the set of lower anchoring elements is great enough that it remains at the ground beneath the water for all barrier configurations. In the presently discussed alternative embodiment, the weight of the set of lower anchoring elements may be chosen such that it is not sufficient to hold down the component of the buoyancy of the set of intermediate floats when the depth of water exceeds a certain value, causing the set of lower anchoring elements to be lifted from the ground beneath the water. An alternative manner in which the set of lower anchoring elements is kept above the ground beneath the water is by use of active land- type and or active water-type tensioning apparatus, as discussed later, or by use of floats or weights of variable buoyancy. Such a gap, between the ground beneath the water and the set of lower anchoring elements, which could be created only temporarily, could be useful to prevent access to dangerous marine life which reside near the water's surface or to boats while allowing passage to benthic life or submarines.

[0068] Comparing Figures 1 to 7, the parallel 30 and perpendicular 31 , 32 portions of the barrier structure assembly 10 each comprise two fold-lines when deployed in water. Alternative embodiments are considered in which the barrier would comprise four fold-lines or greater even numbers of fold-lines. In the case of a barrier with four fold-lines, the barrier would be structurally similar to the embodiment of Figure 1 , except for the addition of a second set of intermediate floats and a second set of intermediate weights. The second set of intermediate floats would be connected in between the set of intermediate floats and the set of intermediate weights such that a portion of the barrier screen extends between the second set of intermediate floats and the set of intermediate weights. The second set of intermediate weights would be connected in between the set of intermediate floats and the second set of intermediate floats such that a portion of the barrier screen extends between the second set of intermediate weights and the set of intermediate floats. Accordingly, when placed in a body of water, extension of the barrier can be achieved when the set of intermediate weights moves above the second set of intermediate floats and or when the second set of intermediate weights moves above the set of intermediate floats. Such an embodiment with four, or equally more than four, fold-lines may also be further adapted such that the set of upper floats lies beneath the surface of the water, and/ or such that the set of lower anchoring elements are separated from the ground beneath the water. Methods for achieving these adaptations are described above with regard to an embodiment having two-fold lines; these methods hold equally for embodiments having four or more fold- lines.

[0069] Referring to Figure 8, the barrier screen 15 is made from nine connected rectangular sections, each having long sides of 25 m and short sides of 3 m. Each section is made from nylon net having 4 mm wide holes. Three rectangular sections are placed end to end, their short sides touching, and stitched along adjacent sides. This forms a 75 m by 3 m rectangle which constitutes the first lower portion 22 of the barrier screen 15. Separately, the same process is repeated twice to form the second middle 23 and third upper 24 portions of the barrier screen 15. The first lower 22, second middle 23, and third upper 24 portions of the barrier screen 15 are placed side by side, their long sides touching, and stitched along adjacent sides. This forms a 75 m by 9 m rectangle which constitutes the entire barrier screen 15. Of course, the nine constituent rectangular sections can be stitched together in any order to give the final 75 m by 9 m rectangular barrier screen 15. In an alternative embodiment, one could begin with a rectangular piece of nylon net 75m by 9m which is continuous, instead of being together from smaller constituent rectangles.

[0070] The portion 30 of the barrier screen 15 which will be parallel to the shoreline is formed by the central three 25 m by 3 m rectangles which are joined along their long sides to form a 25 m by 9 m rectangular section. Similarly, the two portions 31, 32 of the barrier screen 15 which will be perpendicular to the shoreline are formed by the three 25 m by 3 m rectangles either side of the portion 30 parallel to the shoreline.

[0071] Intermediate floats are attached to the barrier screen 15 along the first fold-line of the barrier screen 15, which is located in between the first lower 22 and second middle 23 portions of the barrier screen, thereby forming the set of intermediate floats 19. The intermediate floats are connected directly to the barrier screen 15 along the first fold-line. In alternative embodiments, a tension line will be connected to the barrier screen 15 along the first fold-line and all of the intermediate floats will be connected to the tension line instead. The tension line will be capable of transmitting a tension. In the absence of a tension line, the barrier screen 15 itself will be capable of transmitting the tension. Referring back to the first fold-line, one intermediate float will be attached to the first fold-line at each of the two points where the parallel portion 30 of the barrier structure assembly 10 meets the perpendicular portions 31 , 32. Further intermediate floats will be added such that the support of the set of intermediate floats 19 is sufficiently distributed along the first fold- line. As a minimum requirement, the set of intermediate floats 19 must be sufficiently buoyant to support the resultant weight of the set of intermediate weights 18 and the first lower 22 and second middle 23 portions of the barrier screen 15. This resultant weight is equal to the gross weight less the buoyancy and less any upwards tensile forces exerted by the land-type 34, 35 and/ or water-type 37, 38 tensioning apparatus. The set of intermediate floats 19 are intended to be submerged at all times when the barrier structure assembly 10 is installed (aside from where the barrier meets the shore). This requires that the distance between the set of intermediate floats 19 and the set of lower anchoring elements 20, at all points along these sets, is less than the minimum anticipated depth of water at the location where the barrier structure assembly 10 is to be installed.

[0072] The types of intermediate floats used, and similarly the types of intermediate and upper floats and lower anchoring elements used, can be those known in the state of the art, including those used in conjunction with fishing nets and those used for underwater shark barriers and the like. More specifically, in the case of the lower anchoring elements, these may comprise either a fixing apparatus, such as a bolt for driving into the ground beneath the water, or a weight, such as a lead weight, or a hybrid apparatus comprising both weight and ground fixing. The choice will depend on the nature of the ground beneath the water. For example, bolts will likely be unsuitable for very soft ground. In terms of the connections used to connect the barrier screen 15 to the sets of weights 18 floats 17, 19 and lower anchoring elements 20, those connections known in the state of the art may be used, including those used in conjunction with fishing nets and those used for underwater shark barriers and the like.

[0073] Lower anchoring elements are attached to the lower edge of the barrier screen 15, which is the long side of the first lower portion 22 that is opposite to the first fold-line, thereby forming the set of lower anchoring elements 20. The lower anchoring elements are connected directly to the barrier screen 15 along the lower edge. In alternative embodiments, a tension line will be connected to the barrier screen 15 along the lower edge and all of the lower anchoring elements will be connected to the tension line instead. The tension line will be capable of transmitting a tension. In the absence of a tension line, the barrier screen 15 itself will be capable of transmitting the tension. Referring back to the lower edge, one lower anchoring element will be attached to the lower edge at each of the two points where the parallel portion 30 of the barrier structure assembly 10 meets the perpendicular portions 31 , 32. Further lower anchoring elements will be added such that the holding effect of the set of lower anchoring elements 20 is sufficiently distributed along the lower edge. As a minimum requirement, the set of lower anchoring elements 20 will provide sufficient downwards force to exceed the resultant buoyancy of the barrier screen 15, the set of intermediate floats 19, the set of intermediate weights 18, and the set of upper floats 17. This resultant buoyancy is equal to the gross buoyancy less the weight and plus any upwards tensile forces exerted by the land-type 34, 35 and/ or water-type 37, 38 tensioning apparatus.

[0074] Intermediate weights are attached to second fold-line of the barrier screen 15, which is located in between the second middle 23 and third upper 24 portions of the barrier screen, thereby forming the set of intermediate weights 18. The intermediate weights are connected directly to the barrier screen 15 along the second fold-line. In alternative

embodiments, a tension line will be connected to the barrier screen 15 along the second fold-line and all of the intermediate weights will be connected to the tension line instead. The tension line will be capable of transmitting a tension. In the absence of a tension line, the barrier screen 15 itself will be capable of transmitting the tension. Referring back to the second fold-line, one intermediate weight will be attached to the second fold-line at each of the two points where the parallel portion 30 of the barrier structure assembly 10 meets the perpendicular portions 31 , 32. Further intermediate weights will be added such that the holding effect of the set of intermediate weights 18 is sufficiently distributed along the second fold-line. As a minimum requirement, the set of intermediate weights 18 will provide sufficient downwards force to overcome any upwards tensile forces exerted on the barrier screen 15 by the water-type 37, 38 and land-type 34, 35 tensioning apparatus. The set of intermediate weights 18 are intended to not touch the ground beneath the water at any time when the barrier structure assembly 10 is installed (aside from where the barrier meets the shore). This requires that the distance between the set of intermediate floats 19 and the set of intermediate weights 18 is no greater than the distance between the set of lower anchoring elements 20 and the set of intermediate floats 19 at all points along these sets.

[0075] Upper floats are attached to the upper edge of the barrier screen 15, which is the long side of the third upper portion 24 that is opposite to the set of intermediate weights 18 , thereby forming the set of upper floats 17. The upper floats are connected directly to the barrier screen 15 along the upper edge. In alternative embodiments, a tension line will be connected to the barrier screen 15 along the upper edge and all of the upper floats will be connected to the tension line instead. The tension line will be capable of transmitting a tension. In the absence of a tension line, the barrier screen 15 itself will be capable of transmitting the tension. Referring back to the upper edge, one upper float will be attached to the upper edge at each of the two points where the parallel portion 30 of the barrier structure assembly 10 meets the perpendicular portions 31 , 32. Further upper floats will be added such that the support of the set of upper floats 17 is sufficiently distributed along the upper edge. As a minimum requirement, the set of upper floats 17 must be sufficiently buoyant to support the resultant weight of the set of intermediate weights 18 and the second middle 23 and third upper 24 portions of the barrier screen 15. This resultant weight is equal to the gross weight less the buoyancy and less any upwards tensile forces exerted by the land-type 34, 35 and/ or water-type 37, 38 tensioning apparatus. Any barrier weight which is not supported by the set of upper floats 17 will be supported by the set of intermediate floats 19 or by an upwards tensile forces exerted by the land-type 34, 35 and/ or water-type 37, 38 tensioning apparatus.

[0076] As a consequence of the above -discussed design considerations for the sets of weights 18, floats 17, 19 and lower anchoring elements 20, the set of intermediate floats 19 will float in the body of water whilst the set of lower anchoring elements 20 remain at the ground beneath the water, thereby holding the first lower portion 22 of the barrier structure assembly 10 taut. Similarly, the set of upper floats 17 will remain at the surface of the body of water whilst the set of intermediate weights 18 apply a downwards force on the barrier screen 15, thereby holding the third upper portion 24 of the barrier structure assembly 10 taut. Further provisions must be introduced to ensure that the second middle portion 23 of the barrier structure assembly 10 will be held taut at all times between set of intermediate weights 18 and the set of

intermediate floats 19. Specifically, this taut nature of the second middle portion 23 of the barrier structure assembly 10 is ensured by using the water-type 37, 38 and land-type 34, 35 tensioning apparatus to position the set of upper floats 17 such that the horizontal displacement between the set of lower anchoring elements 20 and the set of upper floats 17 exceeds the width of the second middle portion 23 of the barrier structure assembly 10 at all points along these sets. The width of the second middle portion 23 of the barrier structure assembly 10 is defined as the distance between the set of intermediate floats 19 and the set of intermediate weights 18. This taut nature of the first lower 22, second middle 23 and third upper 24 portions of the barrier structure assembly 10 is true for all water depths for which the barrier is designed, the only exception being where the barrier meets the shore. Where the barrier structure assembly 10 meets the shore, in particular at low tide, the sections of the barrier screen 15 between the sets of floats, weights and lower anchoring elements may fall slack.

[0077] In alternative embodiments, the second middle portion 23 of the barrier structure assembly 10 could instead be constructed from a rigid material or, alternatively still, it could be allowed to become slack. A slack second middle portion 23 of the barrier structure assembly 10 would only be adopted if this does not risk entangling of the barrier structure assembly 10 or rubbing of the second middle portion 23 of the barrier structure assembly 10 on the ground. The amount of slack material in the second middle portion 23 would be less for greater separations between the intermediate weights and intermediate floats. As a consequence, when the barrier structure assembly 10 is at its lowest height the second middle portion 23 will have a minimal amount of slack material and so is not expected to rub on the ground.

[0078] Subject to the requirements set out so far, the number of floats and weights used in each set can be chosen at will - the number of floats and weights illustrated in the drawings is purely representative and is not to be interpreted as a suitable design choice. For example, in one embodiment, the set of upper floats 17 could comprise two upper floats; one at each point where the parallel portion 30 of the barrier structure assembly 10 meets the two perpendicular portions 31 , 32. In this arrangement, the tension applied by the land-type 34, 35 and water-type 37, 38 tensioning apparatus would have to be sufficient to support the sections of the third upper portion 24 of the barrier structure assembly 10 which are in between the tensioning apparatus. In a similar manner, the sets of intermediate floats 19, intermediate weights 18, and lower anchoring elements 20 could each comprise two of the respective float, weight or anchoring element. In an alternative embodiment, all of the weights, floats and lower anchoring elements in their respective sets could be concentrated close to the water-type tensioning apparatus 37, 38. In addition, whilst embodiments described so far comprise one weight, float and lower anchoring element placed at each of the two vertices of the barrier structure assembly 10 where the parallel portion 30 meets the two perpendicular portions 31 , 32, this is not an essential requirement. Furthermore, subject to the above, the relative positions of floats and weights in different sets are unimportant and the positions depicted in the drawings are purely illustrative.

[0079] Alternative constructions of the barrier screen 15 are also considered. Preferred embodiments comprise a barrier screen in which the portions of the barrier structure assembly 10 perpendicular to the shoreline are tapered, having less material towards the shore. In the embodiment of Figure 8, the two portions 31 , 32 of the barrier structure assembly 10

perpendicular to the shore, once unfolded, comprise 25 m by 9 m rectangles, having one 9 m side stitched to the parallel portion 30 of the barrier structure assembly 10. An alternative

embodiment is considered whereby the 25 m by 9 m rectangles of the perpendicular portions 31 , 32 of the barrier structure assembly 10 are each replaced by right-angled triangles having perpendicular sides of length 25 m by 9 m, the latter 9 m length being stitched to a 9 m side of the parallel portion 30 of the barrier structure assembly 10. Tapering the barrier screen 15 in such a manner may help the barrier structure assembly 10 to adapt to a changing water depth without becoming tangled.

[0080] Referring to Figure 9, both water-type tensioning apparatus 37, 38 are identical; each comprising tension lines connecting an upper corner 42 of the barrier structure assembly 10 to a first support via a first jumper float 43 connected in between the tension lines. The water- type tensioning apparatus 37, 38 further comprises tension lines connecting an intermediate corner 45 of the barrier structure assembly 10 to a second support, which may be the ground beneath the water, via a second jumper float 46 connected in between the tension lines. Each support may be an anchor or the ground itself; in Figure 9, both the first 43 and the second 46 jumper floats fix to the same point on the ground, however in alternative embodiments the first and second supports do not have to be at the same position. The upper corners of the barrier structure assembly 10 are the two points on the upper edge of the barrier screen 15 where the parallel portion 30 of the barrier meets the perpendicular portions 31, 32. Similarly, the intermediate comers of the barrier structure assembly 10 are the two points on the first fold-line of the barrier screen 15 where the parallel portion 30 of the barrier meets the perpendicular portions 31 , 32. [0081] Referring to the embodiment 55 of Figure 10, tension lines connect the upper corner 42 of the barrier structure assembly 10 to a support via a jumper float 57 connected in between the tension lines. Optionally, a tension line will be introduced to connect the jumper float 57 to the intermediate corner 45 of the barrier structure assembly 10, and / or a tension line may be introduced to connect the intermediate corner 45 of the barrier structure assembly 10 to the same support that is connected to the jumper float 57. The support may be an anchor or the ground itself. In a further alternative embodiment of the water-type tensioning apparatus, tension lines connect the upper corner of the barrier to a support via one or more jumper floats, and or one or more weights, connected in between the tension lines.

[0082] The water-type 37, 38 and land-type 34, 35 tensioning apparatus serve the purpose of maintaining tension in the barrier structure assembly 10. This tension is necessary to hold the barrier structure assembly 10 in its three-sided shape. In addition, the tension is necessary to maintain the staggered nature of the barrier structure assembly 10, as depicted in Figures 9 and 10, whereby the set of intermediate floats 19 are nearer to the second body of water 13 than the set of upper floats 17. Relative to the two intermediate corners of the barrier structure assembly 10, each of the two upper corners of the barrier structure assembly 10 are positioned nearer to the shore and nearer to the center of the parallel portion 30 of the barrier structure assembly 10. More specifically, the water-type tensioning apparatus 37, 38 position the upper corners such that the horizontal displacement between the set of lower anchoring elements 20 and the set of upper floats 17 exceeds the width of the second middle portion 23 of the barrier structure assembly 10 at all points along these sets. The width of the second middle portion 23 of the barrier structure assembly 10 is defined as the distance between the set of intermediate floats 19 and the set of intermediate weights 18. The water-type tensioning apparatus 37, 38 are able to position the upper and intermediate corners of the barrier structure assembly 10 through choice of the direction and magnitude of the tension in the tension lines of the water-type tensioning apparatus which connect to these corners. The magnitude of the tension in the tension lines of a water-type tensioning apparatus 37, 38 is a function of the size of the jumper float, the length of the tension lines, and the positioning of the supports. For example, in the embodiment of Figure 9 wherein both jumper floats 43, 46 fix to the same point at the ground, in order to position the intermediate corner 45 to be nearer to this point than the upper corner 42, the tension in the tension line connecting to the intermediate corner 45 must be greater than the tension in the tension line connecting to the upper corner 42. In order to achieve this difference in tension, either the second jumper float 46 must be bigger than the first jumper float 43 , or the tension lines connecting to the second jumper float must be shorter than the corresponding tension lines connecting to the first jumper float.

[0083] The effect of tension is exemplified by considering the parallel portion 30 of the barrier structure assembly 10 in the case where each set of floats 17, 19 and weights 18 only comprises two of the respective float and weight, one at each edge where the parallel portion 30 of the barrier structure assembly 10 meets the perpendicular portions 31, 32. With such an arrangement, the parallel portion 30 of the barrier structure assembly 10 would sag in between each float and each weight, forming a catenary-like profile. If this sagging is excessive, it could result in rubbing of the barrier screen 15 on the ground beneath the water and sinking of the upper edge of the barrier screen below the surface of the water. The barrier screen 15 may be further deformed by tidal currents and or waves, which could result in entangling of the barrier screen. Likelihood of such barrier entanglement is greater for smaller separations between the intermediate corners of the barrier structure assembly 10 and the adjacent upper corners. In order to avoid the problems associated with sagging and deformation, it is necessary to either add further weights and floats to the barrier and or increase the tension applied by the water-type 37, 38 and land-type 34, 35 tensioning apparatus.

[0084] In order to generate tension in the barrier structure assembly 10, each land-type tensioning apparatus 34, 35 applies a tension on the barrier screen 15 which is directed inland. Simultaneously, each water-type tensioning apparatus 37, 38 applies a tension which is directed approximately 45 degrees away from the shoreline and approximately perpendicular with respect to the other water-type tensioning apparatus. Employing jumper floats in the embodiments of Figures 9 and 10 allows the water-type tensioning apparatus 37, 38 to continuously apply tension to the barrier screen 15 despite the changing height of the barrier. For example, when the height of the barrier structure assembly 10 decreases, the distance between the ground and the intermediate and upper corners of the barrier decreases, however the tension lines in the water-type tensioning apparatus 37, 38 remain taut as they are pulled in the direction of the jumper float. In addition, in order to keep each intermediate corner of the barrier structure assembly 10 further from the shoreline than the adjacent upper corner, the water-type tensioning apparatus 37, 38 apply a greater tension to the intermediate corners than the upper corners.

[0085] In the case that the supports of the water-type tensioning apparatus 37, 38 comprise a fixing to the ground, bolts may be used for this purpose. The connection means used for the water-type tensioning apparatus 37, 38 is not necessarily the same as that used for the set of lower anchoring elements 20.The jumper floats used, and their connections to the tension lines, can be those known in the state of the art, including those used in boating, those used in conjunction with fishing nets and those used for underwater shark barriers and the like.

[0086] Both of the land-type tensioning apparatus 34, 35 are identical, each comprising a fixing and or winch located inland which connects to the barrier screen 15 via one or more tension lines. In one suitable embodiment, each of the land-type tensioning apparatus 34, 35 will comprise multiple tension lines which will attach to one of the 9 m sides of the barrier screen 15 depicted in Figure 8. The attachments to the barrier screen 15 of each of the tension lines will be spread out uniformly along this 9 m side. These multiple tension lines will then converge at a connection point to form a single tension line which is fed into the fixing and or winch. In an alternative embodiment, each of the multiple tension lines will converge to a separate fixing and or winch, the fixings and or winches being arranged in accordance with the folded arrangement of the barrier screen, thereby reducing the chance of barrier entanglement. In any of these embodiments, the tension lines that the land-type tensioning apparatus 34, 35 comprises may be extensions of the previously discussed tension lines that attach to the weights, floats or lower anchoring elements. The tension lines used in the water-type 37, 38 and land-type 34, 35 tensioning apparatus, and equally the tension lines used to connect the weights, floats and lower anchoring elements, can be steel cables, synthetic ropes, chains, or any other tension lines known in the state of the art.

[0087] In alternative embodiments, the barrier may use active water-type and or land- type tensioning apparatus. An active water-type tensioning apparatus may have movable points of connection to the ground beneath the water. This could be achieved by using an

electromechanical device where the water-type tensioning apparatus meets the ground beneath the water. An active land-type tensioning apparatus may have movable points of connection to the land above the water. This could be achieved by using an electromechanical device where the land-type tensioning apparatus meets the land above the water. An active land-type tensioning apparatus may be able to apply a variable tension on the tension lines to which it is connected. This could be achieved, in the case that the tension lines of the land-type tensioning apparatus are connected to a winch, by pulling the tension lines further through the winch manually or automatically. In further alternative embodiments, the barrier may use weights or floats of variable buoyancy.

[0088] A barrier structure assembly 10 according to the present invention affords a substantial degree of flexibility in the sense that the first lower 22, second middle 23 and third upper 24 portions of a barrier structure assembly 10 are able to move relative to each other. This has the advantage that if a shark or other large marine creature were to swim into the barrier structure assembly 10, the barrier would oppose the shark with a less firm initial reaction, being able to deform to some extent to accommodate for the shark. This is beneficial on several levels. Firstly, the less firm initial reaction reduces the likelihood of shark entanglement as well as the likelihood of damage to the barrier structure assembly 10.

Secondly, the less firm initial reaction is beneficial since it reduces the chance of the lower anchoring elements 20 being lifted from the ground below during the collision. If the lower anchoring elements 20 were lifted from the ground, harmful marine creatures such as sharks could pass through the resultant gap.

[0089] Installation of the barrier structure assembly 10 will often not require specialized personnel. One possible method for installing the barrier structure assembly 10 embodiment of Figure 1 consists in the following consecutive steps:

a. Attach the sets of weights 18, floats 17, 19 and lower anchoring elements 20 to the barrier screen 15. b. Fix the supports of both water-type tensioning apparatus 37, 38 at their desired

positions; leave unconnected the tension lines of the water-type tensioning apparatus

37, 38 which are to be connected to the barrier screen 15. Fix both land-type tensioning apparatus 34, 35 inland at their desired positions, leave unconnected the tension lines of the land-type tensioning apparatus 34, 35 which are to be connected to the barrier screen 15. c. Connect the barrier screen 15 to the respective tension lines of each land-type 34, 35 and water-type 37, 38 tensioning apparatus. The barrier structure assembly 10 is currently slack since the tension lines of the land-type 34, 35 tensioning apparatus have not yet been wound in by the winches.

d. In the case that the lower anchoring elements 20 comprise fixings, fix the lower

anchoring elements 20 to the ground.

e. Using the winches, wind in the tension lines of the land-type tensioning apparatus 34, 35.

This process tensions the barrier screen 15, displacing the jumper floats from their rest positions above their respective supports beneath them. In this manner, both the land-type 34, 35 and water-type 37, 38 tensioning apparatus exert a tension on their respective tension lines, and the barrier screen 15 assumes its desired shape.

[0090] The barrier embodiments described so far have only been concerned with a three- sided barrier structure assembly 10 used adjacent to a shoreline, comprising one portion 30 which is parallel to the shoreline and two portions 31 , 32 which are perpendicular to the shoreline. Further embodiments are considered with alternate shapes. For example, in one embodiment the barrier is three-sided, having a portion parallel to the shoreline, and two adjacent portions which meet the parallel portion at an angle other than perpendicular.

[0091] In another embodiment, depicted in Figure 11 , the barrier 60 is one-sided and comprises a central portion 62 and two side portions 64, 65. Water-type tensioning apparatus may not be required and, as depicted in Figure 12, raised land-type tensioning apparatus 67, 68 are used. The central portion 62 of the barrier 60 may be analogous to the parallel portion 30 of the barrier embodiment of Figure 1. Each raised land-type tensioning apparatus 67, 68 comprises a common connection point 70 mounted on a rigid vertical support 72 such that the height of the common connection point is greater than the height of the water at high tide. The vertical support 72 will be fixed in a ground above or below the surface of the water. The common connection point may comprise a fixing and or a winch. Tension lines attach the central portion 62 of the barrier 60 to the common connection point 70; as depicted in Figure 12 each tension line may attach to the central portion 62 of the barrier 60 at a point at the same height as the set of lower anchoring elements 75 or the set of intermediate floats 76 of the set of intermediate weights 77 or the set of upper floats 78. In order that the tension lines maintain tension throughout the range of heights that the water can take, the tension lines may be made from elastic material or may comprise coils or, alternatively, weights or floats may be attached to the tension lines at a point in between the central portion 62 of the barrier 60 and the common connection point 70. Each side portion 64, 65 comprises slack barrier screen material which is connected in between the central portion 62 of the barrier screen 80 and the vertical support 72. The side portion 64 may be connected to the central portion 62 using stitching meanwhile the side portion may be connected to the vertical support 72 via conventional means. Using slack material in a barrier can lead to several problems, however since the side portions 64, 65 of the barrier are much smaller than the central portion 62, the relatively small size of the side portions 64, 65 should reduce the impact of any such problems. In alternative embodiments, the common connection point 70 of the raised land-type tensioning apparatus 67, 68 may instead be mounted on a raised part of land which is still above the height of the water at high tide, and a vertical support will not be used. Raised land-type tensioning apparatus 67, 68 may also be used to replace the land-type tensioning apparatus 34, 35 in the three-sided barrier embodiment 10 of Figure 1. In such a case, the side portion 64 of the raised land-type tensioning apparatus 67, 68 would attach to a portion 31 , 32 of the barrier structure assembly 10 of Figure 1 which is perpendicular to the shoreline.

[0092] In yet another embodiment, depicted in Figure 13, the barrier 85 is four-sided.

This four-sided embodiment comprises four water-type tensioning apparatus 87, 88, 89, 90, each of which are constructed according to the arrangement of Figure 9. Specifically, the tension lines of each tensioning apparatus 87, 88, 89, 90 will be directed, as viewed from above,

approximately 135 degrees away from both sides of the vertex to which they attach. Angles other than 135 degrees may be used, provided that each water-type tensioning apparatus 87, 88, 89, 90 still applies tension to both portions that meet at the vertex, due to applying a tension which is directed, as viewed from above, to have a first resolved component parallel to one of the sides and a second resolved component parallel to the remaining side. No land-type tensioning apparatus are required. The barrier screen 92 of this four-sided embodiment can be considered as an extension to the barrier screen 15 of Figure 8. In order to form the barrier screen 92 of the four-sided embodiment, the 9 constituent 3 m by 25 m rectangular sections in Figure 8 are stitched to a further three 3 m by 25 m rectangular sections to form a continuous 100 m by 9 m rectangular screen 92. Following this, the two 9 m sides of the 100 m by 9 m rectangle are stitched to each other. [0093] The 100 m by 9 m barrier screen 92 is comprised of four adjacent connected 25 m by 9 m rectangles. In use, each side of the barrier 85 in Figure 13 is identical and will comprise one of these 25 m by 9 m rectangles. Each water-type tensioning apparatus 87, 88, 89, 90 will be attached at each edge where two sides of the barrier 85 meet. As a result, the water-type tensioning apparatus 87, 88, 89, 90 will maintain the barrier screen 92 in a square geometry as viewed from above.

[0094] In a similar manner to the embodiment of Figure 8, the set of upper floats 94 will comprise one upper float at each corner of the barrier 85 where the four sides meet one another, as well as further upper floats in between these corners. The sets of intermediate floats 95, intermediate weights 96, and lower anchoring elements 97 will be arranged in an analogous manner.

[0095] The four-sided embodiment 85 can be situated in an open body of water and does not have to be placed adjacent to a shoreline. Such an arrangement may be particularly suited to fish farming applications. Alternative embodiments are considered whereby the number and arrangement of water-type tensioning apparatus 87, 88, 89, 90 is varied, and or the geometry of the barrier screen 92, so as to modify the square geometry of the embodiment of Figure 13 into any suitable polygon.

[0096] All barrier embodiments discussed in this document are suitable for use in a body of water. It is implied that such a body of water may comprise a sea, ocean, inland reservoir, river, or indeed any underwater environment of the like.

[0097] The barrier screen 15, 80, 92 of embodiments described so far comprises a nylon net. Alternative types of barrier screen material are considered such as flexible nets made from rope, metal and plastic. Instead, the barrier screen material may comprise an interlinking mesh structure made from metal or other materials. Still alternatively, the barrier screen material may be a continuous flexible sheet of material such as plastic, which may be impermeable or semipermeable. In the semi-permeable case, the sheet would allow passage of only certain ions or molecules.

[0098] In general, the material of the barrier screen 15, 80, 92 shall be chosen to fit the particular circumstances in which the net is used. Where the barrier structure assembly 10, 60, 85 is used at a beach, or at any other location in which marine species may be in the water, the barrier screen material will be chosen to reduce the likelihood of harming any marine species. For example, the size of any holes in the barrier screen material will be chosen to minimize the chance of entanglement with fish or other marine species, whilst still being suitably sized to block any species that the barrier structure assembly 10, 60, 85 is designed to block. In addition, the strength and durability of the barrier screen material will be chosen to fit the environment. For example, if the land-type and or water-type tensioning apparatus connect directly to the barrier screen, the barrier screen must be capable of transmitting any associated tension. Preferred barrier embodiments are concerned with blocking sharks and jellyfish and the like; in these cases, a sufficiently strong and durable barrier screen material will be used. Subject to the above, barrier screen materials known in the prior art can be used.

[0099] Instead of using a flexible material for the barrier screen, embodiments are considered which use a semi-rigid material. For example, the barrier screen may comprise rigid plates which are joined together using hinges. If the barrier is many-sided, for example if it takes the three-sided arrangement of Figure 1, the barrier screen may further comprise bellow-like flexible components where these sides meet one another.

[00100] While this invention has been described as having exemplary designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Claims

1. A barrier structure assembly for use underwater, the assembly comprising a barrier screen and:

i) a set of upper floats, which, in use, are connected to an upper edge of the barrier screen;

ii) a set of lower anchoring elements, which, in use, are connected to a lower edge of the barrier screen;

iii) a set of intermediate floats, which, in use, are connected to a first fold-line of the barrier screen between the set of upper floats and the set of lower anchoring elements, and wherein a first lower portion of the barrier screen extends between the set of lower anchoring elements and the set of intermediate floats;

iv) a set of intermediate weights, which, in use, are connected to a second fold-line of the barrier screen between the set of intermediate floats and the set of upper floats, and wherein a second middle portion of the barrier screen is provided between the set of intermediate weights and the set of intermediate floats, and a third upper portion of the barrier screen extends between the set of the intermediate weights and the set of upper floats; and wherein, when placed in a body of water:

i) the set of upper floats float at a first top height in the body of water;

ii) the set of lower anchoring elements hold or anchor the barrier screen at a second bottom height in the body of water;

iii) the set of intermediate floats float at a third intermediate height in the body of water, holding the first lower portion of the barrier screen taut;

iv) the set of intermediate weights hold the third upper portion of the barrier screen taut and take up a fourth intermediate height in the body of water, while the set of intermediate weights can ascend relative to the set of intermediate floats to allow for extension of the structure.

2. The assembly of claim 1 , further comprising at least one tensioning apparatus for connecting the assembly to at least one support, wherein each support may be above or below the surface of the water.

3. The assembly of claim 2, wherein the support, or one of the supports, is the ground.

4. The assembly of claim 2, wherein the support, or one of the supports, comprises a winch and or fixing to the ground.

5. The assembly of any of claims 2 to 4, wherein the, or one of the, tensioning apparatus comprises a tension line and a float, the tension line for connecting the upper edge of the barrier screen to the support, or one of the supports, and the float for connecting to the tension line at a point between the upper edge and the support, or one of the supports.

6. The assembly of any of claims 2 to 5, wherein the, or one of the, tensioning apparatus comprises a tension line and a float, the tension line for connecting the first fold-line of the barrier screen to the support, or one of the supports, and the float for connecting to the tension line at a point between the first fold-line and the support, or one of the supports.

7. The assembly of any of claims 2 to 6 wherein, in use, the assembly is near to a shoreline and forms a barrier across the body of water as viewed from above, such that the assembly separates water on one side of this barrier from water on the other side of the barrier, and wherein each end of this barrier is fixed to land or a shore by one of the tensioning apparatus such that the assembly separates a first body of water from a second body of water.

8. The assembly of claim 7 wherein the assembly forms a substantially three-sided barrier through the body of water as viewed from above, having two vertices, one vertex at each of the two points where the sides of the barrier meet one another, and wherein at each of the two vertices one of the tensioning apparatus connects to the barrier.

9. The assembly of claim 8 wherein the tensioning apparatus connected to each of the

vertices of the barrier apply tension to both sides of the barrier that meet at the vertex by applying a tension which is directed, as viewed from above, to have a first resolved component parallel to one of the sides and a second resolved component parallel to the remaining side.

10. The assembly of any preceding claim wherein, in use, the set of upper floats is arranged to float on or near the surface of the body of water.

1 1. The assembly of any preceding claim wherein, in use, the set of lower anchoring elements is arranged to lie on or near the ground beneath the water.

12. The assembly of any preceding claim, wherein no sets of floats or weights are attached to the barrier screen in between the set of intermediate weights and the set of intermediate floats such that, when the assembly is in use, the second middle portion of the barrier screen hangs between the set of intermediate weights and the set of intermediate floats.

13. The assembly of any of claims 1 to 1 1, further comprising additional sets of floats and weights attached to the barrier screen in between the set of intermediate floats and the set of intermediate weights, such that the second middle portion of the barrier screen, when the assembly is in use, assumes a folded configuration.

14. The assembly of any of claims 1 to 12 wherein:

i) the set of upper floats has a buoyancy which is greater in magnitude than the resultant weight, when the assembly is in use, of the second middle and third upper portions of the barrier screen and the set of intermediate weights, wherein the resultant weight is the weight less the buoyancy less any upward tensile forces exerted by tensioning apparatus;

ii) the set of lower anchoring elements is able to exert a force on the barrier screen which is greater in magnitude than the resultant buoyancy, when the assembly is in use, of the barrier structure assembly, wherein the resultant buoyancy is the buoyancy, less the weight, plus any upward tensile forces exerted by tensioning apparatus;

iii) the set of intermediate floats has a buoyancy which is greater in magnitude than the resultant weight, when the assembly is in use, of the first lower and second middle portions of the barrier screen and the set of intermediate weights, wherein the resultant weight is the weight less the buoyancy less any upward tensile forces exerted by tensioning apparatus.

15. The assembly of any preceding claim wherein the barrier screen comprises a material with holes, such as a net or mesh, which is suitable for filtering out solid species in water.

16. The assembly of any of claims 1 to 14 wherein the barrier screen comprises material suitable for filtering out liquid species from water.

17. The assembly of any preceding claim wherein the barrier screen comprises rigid plates which are connected using hinges.

18. A method for installing a barrier structure assembly for use underwater, the method comprising connecting a barrier screen to:

iv) a set of intermediate weights, which, in use, are connected to a second fold-line of the barrier screen between the set of intermediate floats and the set of upper floats, and wherein a second middle portion of the barrier screen is provided between the set of intermediate weights and the set of intermediate floats, and a third upper portion of the barrier screen extends between the set of the intermediate weights and the set of upper floats; such that when placed in a body of water:

i) the set of upper floats float at a first top height in the body of water;

19. The method of claim 18, further comprising using tension lines to connect the assembly to at least one support, wherein each support may be the ground and may be above or below the surface of the water.

20. The method of claim 19, wherein a point along the upper edge of the barrier screen is connected to the support, or one of the supports.

21. The method of claims 19 or 20, wherein a point along the first fold-line of the barrier screen is connected to the support, or one of the supports.

22. The method of any preceding method claim further comprising using the assembly near to a shoreline and arranging the assembly such that it forms a barrier across the body of water as viewed from above, such that the assembly separates water on one side of this barrier from water on the other side of the barrier, fixing each end of this barrier to land or a shore such that the assembly separates a first body of water from a second body of water.

23. The method of claim 22 further comprising arranging the assembly into a substantially three-sided barrier through the body of water as viewed from above, having two vertices, one vertex at each of the two points where the sides of the barrier meet one another, by connecting each of the two vertices of the barrier to one of the supports.

24. The method of claim 23 wherein, at each of the vertices of the barrier, a connection to one of the supports is arranged which applies tension to both sides of the barrier that meet at the vertex by applying a tension which is directed, as viewed from above, to have a first resolved component parallel to one of the sides and a second resolved component parallel to the remaining side.

25. The method of any preceding method claim wherein, in use, the set of upper floats is arranged to float on or near the surface of the body of water.

26. The method of any preceding method claim wherein, in use, the set of lower anchoring elements is arranged to lie on or near the ground beneath the water.

27. The method of any preceding method claim, wherein no sets of floats or weights are attached to the barrier screen in between the set of intermediate weights and the set of intermediate floats such that the second middle portion of the barrier screen hangs between the set of intermediate weights and the set of intermediate floats.

28. The method of any of method claims 18 to 26, further comprising attaching additional sets of floats and weights to the barrier screen in between the set of intermediate floats and the set of intermediate weights, such that the second middle portion of the barrier screen assumes a folded configuration.