WO2020245168A1

WO2020245168A1 - Security fencing

Info

Publication number: WO2020245168A1
Application number: PCT/EP2020/065307
Authority: WO
Inventors: Timothy MESSELIS
Original assignee: Guardiar Europe Bvba
Priority date: 2019-06-04
Filing date: 2020-06-03
Publication date: 2020-12-10
Also published as: EP3980613B1; GB2584460B; GB201907963D0; ZA202202310B; EP3980613C0; GB2584460A; EP3980613A1

Abstract

A security fence panel comprising mutually confronting security mesh sheets which in use are spaced apart, the security mesh sheets being connected by intermediate sheets wherein in use the intermediate sheets are inclined to the horizontal and extend across the space between the confronting security mesh sheets.

Description

Security Fencing

The present invention relates to a security fence panel and security fencing created therefrom.

Security fencing is typically used for the construction of perimeter fences around prisons and other high security buildings, at national borders or around oil refineries and the like which may be located in hostile environments.

Security fencing is typically constructed of welded steel wire mesh or other high strength ma terial and is normally designed to resist unaided climbing ("anti-climb") and sometimes also to resist attack by power tools such as angle grinders ("anti-grind") or bolt cutters. In some situ ations, it is also desirable to offer some protection against projectiles, even including bullets.

Anti-climb security fencing typically employs mesh openings that are too small to allow hand holds or footholds, and a gauge of wire that is too thick to be easily cut with bolt cutters.

EP3149260B1 discloses a fencing mesh having a first set of wires which are arranged essen tially parallel with respect to each other and a second set of wires which are arranged essen tially parallel with respect to each other and intersect the first set of wires, wherein the wires of the first set of wires are connected to the wires of the second set of wires at locations where they intersect. The wires of the first set of wires are connected to the wires of the second set of wires by welding.

A fencing mesh as disclosed in EP3149260B1 has the disadvantage that it can be damaged or destroyed by an intruder, for example by an intruder using a grinding tool.

Thus, protection against power tools such as angle grinders has proved to be problematic, particularly since cordless angle grinders and the like have become more widely available.

An object of the present invention is to provide security fencing with improved anti-grind fea tures.

Our unpublished patent application PCT/IB2018/052480 discloses a fencing mesh assembly comprising a front mesh panel, a rear mesh panel and several cross mesh (i.e. intermediate) panels, wherein the cross mesh panels are disposed between and are connected to the front mesh panel and the rear mesh panel, and are distributed over the front mesh panel and over the rear mesh panel, wherein in the installed state, adjacent cross mesh panels are arranged spaced apart from each other, and wherein in the installed state the front mesh panel and the rear mesh panel are spaced apart from each other.

The fencing disclosed in PCT/IB2018/052480 is security fencing. However, PCT/IB2018/052480 only discloses constructions having horizontal cross mesh (i.e. interme diate) panels.

The aim of the present invention is to provide a security fencing with improved anti-grind prop erties, as well as anti-climb properties and projectile resistance.

According to a first aspect of the present invention, there is provided a security fence panel comprising mutually confronting security mesh sheets which in use are spaced apart, the se curity mesh sheets being connected by intermediate sheets wherein in use the intermediate sheets are inclined to the horizontal and extend across the space between the confronting security mesh sheets.

The term“fence panel” is to be construed in accordance with the normal use of the word to relate to a panel that can be used in combination with fence posts to create a fence. The fence panel is therefore not self-supporting and is not sufficient to create a fence or other barrier alone, without some form of support.

A security fence panel is to be construed to mean a fence panel that has anti-grind properties (i.e. an anti-grind fence panel). Anti-grind may be defined with reference to ASTM F2781-10, in that a fence panel is considered anti-grind if it meets one of the ratings in this document. For example, a security fence may be anti-grind if it withstands attack with a grinding tool for at least 5 minutes, as stipulated in ASTM F2781-10.

For the purposes of defining the fence panel in more detail, it is to be understood that said panel has a length, a height and a depth. The height of the fence panel is the distance along the security mesh sheet in the direction perpendicular to the surface on which it is to be posi tioned. The length of the fence panel is the distance along the security mesh sheet in the direction parallel to the surface on which it is to be positioned. The depth of the fence panel is the distance between the external faces of the two security mesh sheets. The fence panel does not have to be positioned on a surface in order to have such dimensions and these dimensions are intended to improve the clarity of the definitions herein only. For example, it is to be understood that the fence panel has a height even when not positioned on a surface and it may be clear to the skilled person based on the arrangement of the fence panel which dimension is the height and which is the length.

One dimension of the panel may be longer than the other. The intermediate sheets may ex tend along at least part, if not all, of the longer dimension. The height of the fence panel may be longer than the length of the fence panel. The intermediate sheets may extend along at least part of the height of the fence panel. The intermediate sheets may extend along the entire height of the fence panel.

The intermediate sheets can transfer forces acting on one security mesh sheet to the other security mesh sheet, thereby increasing the strength of the security fence panel. The interme diate sheets preferably connect the security mesh sheets at a plurality of positions along the length of the security fence panel.

Preferably the intermediate sheets are substantially vertical panels. Vertical is defined relative to the surface on which the fence panel is to be positioned, which defines the horizontal. The intermediate sheets may therefore have an inclination to the horizontal of about 90 degrees.

In preferred embodiments the intermediate sheets have an inclination to the horizontal in the range of 50 degrees to 90 degrees, preferably in the range of 60 degrees to 90 degrees, most preferably in the range of 75 degrees to 90 degrees.

It has surprisingly been found that a much greater time is required for an attacker to breach the security fence panel when the intermediate sheets have an inclination to the horizontal, compared to when the intermediate sheets are positioned horizontally. This is particularly true in the situation where intermediate sheets are connected to the security mesh sheets using a spiral coil, as the spiral coil may move out of position when positioned horizontally due to the vibrations caused by the attacker trying to breach the security fence panel. This is not seen in the present invention in which the coils are positioned at an inclination to the horizontal.

Preferably the intermediate sheets are connected sufficiently loosely to the security mesh sheets to allow movement of the sheets relative to one another, for example when attacked with a power tool. Preferably, only a small amount of movement is allowed. This feature en hances the anti-grind properties of the fence panel by making it difficult to keep the cutting edge of the grinding disc in one position when attacking the fence. Indeed, the sudden move ment of the mesh sheets when engaged by the rotating periphery of the grinding disc may even break the disc in some circumstances. Preferably, the intermediate sheets are connected sufficiently loosely to the security mesh sheets to allow movement of at least 2mm, preferably at least 5mm within the connection.

The panel may comprise more than two intermediate sheets extending between the mutually confronting security mesh sheets, preferably more than five intermediate sheets extending between the mutually confronting security mesh sheets. This can increase the time required to breach the panel. The intermediate sheets may be attached to every other vertical wire in the security mesh sheets. There may be two vertical wires in the security mesh sheets be tween those to which the intermediate sheets are attached. There may be three vertical wires in the security mesh sheets between those to which the intermediate sheets are attached.

Preferably the intermediate sheets are parallel to each other. Preferably the intermediate sheets are pivotally connected to the security mesh sheets to allow stowage of the security mesh fencing in a collapsed state prior to erection. This feature facilitates storage and transport of the security fence panel.

Preferably the intermediate sheets are pivotally connected to the security mesh sheets by spiral connectors threaded through the mesh of the security mesh sheets. This construction typically allows significant movement of the security mesh sheets relative to the intermediate sheets when attacked by an angle grinder, thereby enhancing the anti-grind security of the fence panel. Additionally, this provides a secure connection requiring little material, thereby reducing the weight of the panel and improving the visibility. A spiral connecter can be fitted easily but is difficult to remove without specialised tools and suitable access to the end of the spiral connector. It also provides a connection along the length of the spiral connector.

Preferably the intermediate sheets are formed of mesh. Preferably the spiral connectors are threaded through the mesh of the intermediate sheets and the mesh of the security mesh sheets.

The intermediate sheets may be connected to the security mesh sheets along their longest dimension. This can be achieved using the spiral connector. In this manner, the destruction of the connection means at one point along the longest dimension of the intermediate sheets does not separate said sheets from the security mesh sheets, as there will still be connections along the rest of the intermediate sheet. The term“mesh” is to be construed to cover solid interconnecting wires. The mesh may com prise a plurality of wires extending parallel in a first direction and a plurality of wires extending parallel in a second direction perpendicular to the first, such that each of the wires in the first direction intersects each of the wires in the second direction. The wires may be formed from metal, preferably steel. The wires may be connected together, preferably at each intersection. The wires may be welded together. The mesh of the security mesh sheets and the intermedi ate sheets may be the same.

The spiral connectors may have an internal diameter that is greater than the thickness of the wires in the mesh, thereby creating a loose connection such that the intermediate sheet can move relative to the security mesh sheets.

The security mesh sheets may have a height of at least 1 7m, and preferably have a height of at least 1.9m. The height of the security mesh sheets may be greater than 3m. The height of one of the security mesh sheets in the security fence panel may be greater than the height of the other security mesh sheet. The intermediate sheets may extend the height of the shorter security mesh sheet. The height of the security mesh sheet intended to be on the side of the attacker may be greater than the height of the security mesh sheet intended to be on the side away from the attacker. This can help to reduce the weight and cost of the fence panel without greatly reducing protection from the attacker.

The width of the security fence panel and/or the security mesh sheets may be more than 1.5m, and preferably more than 2m.

The depth of the security fence panel (i.e. the distance between the security mesh sheets) may be between 100mm and 450mm, preferably around 300mm. This is greater than the radius of a commonly available angle grinder disc, thereby increasing the difficulty with which such a tool can breach the security fence panel as an attacker is prevented from reaching one security mesh sheet by the other security mesh sheet. The security mesh sheets are prefera bly parallel to one another.

The intermediate sheets may be spaced apart from one another. The intermediate sheets within the security fence panel may be between 100mm and 500mm apart from one another. There may be between 5 and 15 intermediate sheets in each security fence panel.

The intermediate sheets may be rectangular, with a longer dimension and a shorter dimen sion. The longer dimension of the intermediate sheets may be substantially equal to or shorter than the height of the security mesh sheets. The longer dimension of the intermediate sheets may be greater than 1.7m, preferably greater than 1.9m and most preferably around 3m. Thus, the intermediate sheets will extend over substantially all of the height of the security fence panel. The shorter dimension of the intermediate sheets may be substantially equal to (can be a little smaller) or greater than the depth of the security fence panel, as defined by the spacing between the security mesh sheets. The shorter dimension of the intermediate sheets may be between 100 and 400mm.

One edge of the intermediate sheet along the longer dimension may be connected along its length to one security mesh sheet, while the opposite edge along the longer dimension may be connected along its length to the other security mesh sheet in the fence panel.

Preferably the security mesh sheets have horizontal mesh spacings (i.e. the horizontal dis tance between the centres of adjacent grid wires) of 100mm or less, more preferably 90mm or less, most preferably 80mm or less. Such spacings result in openings that are too small for an attacker to easily gain a foothold, thereby providing anti-climb properties.

Preferably the security mesh sheets have vertical mesh spacings (i.e. the vertical distance between the centres of adjacent grid wires) of 30mm or less, preferably 20mm or less. The vertical mesh spacing may be 13mm or less. Such spacings result in openings that are too small for an attacker to gain a handhold, thereby providing anti-climb properties.

Preferably the security mesh sheets have substantially rectangular mesh openings wherein the ratio of the long side to the short side is at least 2:1 , preferably at least 3:1 , most preferably at least 5:1. These features also make climbing by an attacker more difficult.

Preferably the security mesh sheets are formed from wire having a diameter of 3mm or greater, preferably 3.5mm or greater. Wires of such diameters vibrate under attack by a grind ing tool and have sufficient strength to resist attack by tools such as bolt cutters.

In certain embodiments the intermediate sheets are substantially orthogonal to the security mesh sheets. This feature maximises the transparency of the fencing, which is useful if, for example, CCTV cameras are located behind the fencing and directed outwardly at potential intruders.

In other embodiments, in plan view, the intermediate sheets are inclined at an angle to the security mesh sheets. The angle may be in the range of 10 degrees to 80 degrees, preferably 30 degrees to 60 degrees, most preferably 40 degrees to 50 degrees. In other words, the angle at which the intermediate sheets are attached to the mesh sheets is in the range of 10 degrees to 80 degrees, preferably 30 degrees to 60 degrees, most preferably 40 degrees to 50 degrees. Thus, the intermediate sheets are not orthogonal to the security mesh sheets in these embodiments.

This provides extra protection against penetration of the fence, for example by projectiles. Surprisingly, it has been found that a much greater time is required for an attacker to breach the security fence panel when the intermediate sheets are inclined at an angle to the security mesh sheets in plan view, compared to when the intermediate sheets are orthogonal. This is partly due to the blade of a tool such as an angle grinder getting stuck.

Preferably, all of the intermediate sheets are at the same angle. Preferably, there is no portion of the panel where an intermediate sheet runs parallel to the security mesh sheet. In an em bodiment comprising intermediate sheets at an angle to the security mesh sheets, preferably any transverse cross-section taken orthogonally between the two security mesh sheets inter sects at least one intermediate sheet. In an embodiment comprising intermediate sheets at an angle to the security mesh sheets, preferably any transverse cross-section taken orthogo nally between the two security mesh sheets over the majority of the length of the panel inter sects at least one intermediate sheet. This further improves the anti-grind property and sur prisingly does not unacceptably reduce the transparency of the fence panel.

The intermediate sheets may extend from a first vertical wire in one of the security mesh sheets to a second vertical wire in the other security mesh sheet that is adjacent a vertical wire opposite said first vertical wire. The second vertical wire may be directly adjacent to the vertical wire opposite the first vertical wire. Alternatively, additional vertical wires may be be tween said vertical wires.

In preferred embodiments the security fencing has a rating under ASTM F2781-10 (Table 2) of M5 or higher, preferably M10 or higher, more preferably M15 or higher.

In preferred embodiments the security fencing has a rating under ASTM F2781-10 (Table 2) of A5 or higher, preferably A10 or higher, more preferably A15 or higher.

The fence panel preferably has a visibility index of more than 40%. The security fence panel of the present invention may comprise barbed wire, razor wire, razor tape or the like disposed along its upper edge region. This provides further protection from an attacker.

The security fence panel of the present invention may comprise one or more fastening at one or both ends thereof (i.e. the ends of the length of the fence panel), which is fixable to a supporting post. The fastening is not particularly limited and may comprise any fastening known in the art, such as a fixing plate that is connected to the security mesh sheet by one or more screws or bolts and blind rivet nuts, or by welding. The one or more fastening may connect the security fence panel to the supporting post at a plurality of positions along the height of both the security fence panel and the supporting post.

According to a second aspect of the present invention, there is provided security fencing com prising at least one security fence panel as described above, further comprising supporting posts, wherein the security fence panel is secured to the supporting posts, preferably by one or more tamper-resistant fastenings.

Preferably, a supporting post is positioned between each adjacent security fence panel. The supporting posts may hold the fence panels off the ground, or the fence panels may rest on the ground. The total height of the fencing may be more than 3m.

The supporting posts may be embedded into supporting units, such as concrete blocks. The supporting posts may be intended to be buried in the surface on which the security fencing is to be positioned. Barbed wire, razor wire, razor tape or the like may be connected to the upper end of the supporting posts.

The fastenings may connect the security fence panel to the supporting post at different points along the height and/or the depth of the security fence panel. The fastenings may only be present at the ends of the security fence panel, at either end of its length. The security mesh sheets may extend over at least part of opposing surfaces of the supporting post when con nected together. The supporting post may have a depth smaller than the depth of the security fence panel. In this embodiment, both security mesh sheets may extend over opposing sur faces of the supporting post when connected together.

The security fence panel may be connected to the supporting post at one or more points over its depth. A cover plate may extend over the connection between the security fence panel and the sup porting post. This can improve the strength of the connection, as well as preventing the at tacker from trying to break said connection. The supporting post may be connected to two security fence panels, which may be on opposing sides of the post. A single cover plate may extend over the connection to both security fence panels.

The fencing may comprise any number of supporting posts or security fence panels. The fencing may comprise alternating supporting posts and security fence panels, with supporting posts at either end of the fencing. The fencing may comprise three or more security fence panels and four or more supporting posts.

The security fencing may be used as part of a perimeter fence.

The panels, posts and/or cover plates may be coated, optionally with a polyester. The coating may have a thickness of at least 60 microns, preferably at least 100 microns. This can provide anti-corrosion protection.

According to a third aspect of the present invention, there is provided a kit of parts for security fencing as defined above, the kit comprising a plurality of supporting posts and a plurality of security fence panels as described above.

The number of supporting posts may be one greater than the number of security fence panels. This means that the resulting security fencing can have a supporting post at either end thereof.

The kit may further comprise one or more fastenings for fixing the security fence panels to the supporting posts, as discussed above. The one or more fastenings for fixing the security fence panels to the supporting posts may be integral to the security fence panels.

Also provided is a kit for creating one or more of the security fence panels discussed above. The kit may comprise an even number of security mesh sheets and a plurality of intermediate sheets, as discussed above. The kit may comprise a plurality of intermediate sheets per pair of security mesh sheets.

The kit may comprise a connecting means for connecting the intermediate sheets to the se curity mesh sheets. Said connecting means may comprise a spiral connector. The kit of parts for security fencing according to the third aspect of the invention may comprise the kit for creating the security fence panels or may comprise pre-assembled security fence panels.

According to a fourth aspect of the present invention, there is provided a method for arranging a security fencing as discussed above comprising fixing the security fence panel to the sup porting post such that the intermediate sheets can move relative to the security mesh sheets.

Preferred embodiments of the invention are described below by way of example only with reference to Figures 1 to 1 1 of the accompanying drawings, wherein:

Figure 1 is a front elevation of security fencing in accordance with one embodiment of the invention;

Figure 2 is a transverse cross-section taken on ll-ll of Figure 1 ;

Figure 3 is a top plan view of Figure 1 ;

Figure 4 is an elevation of an intermediate mesh sheet employed in the security fencing of the embodiment of Figure 1 ;

Figure 5 is a perspective view of the security fencing of Figure 1 ;

Figure 5A is a magnified perspective view of part A of Figure 5, showing the pivotal connection between the security mesh sheets and the intermediate mesh sheets;

Figure 5B is an elevation of the spiral connector used to connect the security mesh sheets and the intermediate mesh sheets in Figure 5;

Figure 6 is a magnified view of a portion of the security mesh employed in the embodiment of Figure 1 ;

Figure 7 is a perspective view of a second embodiment;

Figure 7 A is magnified perspective view of part A of Figure 7, showing the pivotal connection between the security mesh sheets and the intermediate mesh sheets; Figure 8 is a diagrammatic partial plan view of the embodiment of Figure 7;

Figure 9 is a side elevation of a further embodiment;

Figure 10 is a front elevation of the embodiment of Figure 9, and Figure 1 1 is a perspective view of the embodiment of Figure 9.

Referring to Figure 1 , one section 1 of a security fencing is shown, comprising two galvanised steel tubular supporting posts 2 of rectangular transverse cross-section (as best seen in Fig ure 3) supporting two spaced apart security mesh sheets 3 and 4 which are formed of welded steel mesh and are clamped at their opposite ends to front and rear faces of the supporting posts 2 by galvanised steel fixing plates 5. Rear fixing plates 5 (see Figure 5) secure the rear security mesh sheet 3 in the same manner as the front two fixing plates 5 secure the front security mesh sheet 4. The fixing plates 5 are secured to the supporting posts 2 by tamper- resistant fastenings 7 such as bolts and blind rivet nuts for example. In other embodiments the fixing plates 5 can be secured to the supporting posts by welding for example.

As shown in Figures 2 and 3, the security mesh sheets 3 and 4 are connected by regularly spaced intermediate mesh sheets 6 (also of welded steel mesh) which extend across the space between them and impede access to the rear security mesh sheet 3 if an attack is made on the front security mesh sheet 4 by an angle grinder or other tool. In particular, the spacing between the front and rear security mesh sheets 3 and 4 is suitably 100mm to 500mm i.e. greater than the radius of a commonly available angle grinder disc.

As best seen in Figure 1 , alternate vertical grid wires of both the security mesh sheets 3 and 4 are connected to an intermediate mesh sheet 6. Thus, the intermediate mesh sheets 6 are orthogonal to the security mesh sheets 3 and 4, as shown in Figure 5A. An intermediate mesh sheet 6 is shown in Figure 4 and has the same spacing between the wires of the mesh as the security mesh sheets 3 and 4.

Figure 5 shows the fencing section in perspective and it will be seen that the top face of the section is also covered by a mesh strip 34.

Referring to Figure 5, the intermediate mesh sheets 6 are attached to the vertical grid wires of the security mesh sheets 3 and 4 by spiral connectors 10, one of which is shown in Figure 5B. During assembly, spiral connectors 10 are threaded through the horizontal grid wires of the security mesh sheets by screwing them in from above. In this embodiment the internal diameter of the spiral connectors 10 is suitably 22mm and the thickness of the steel wire from which the spiral connectors are formed is suitably 4mm. The internal diameter of connectors 10 is large in comparison with the thickness of the vertical grid wires of the security mesh sheets 3 and 4 and intermediate mesh sheets 6 (suitably 3.6mm in each case) which results in a loose pivotal connection between each intermediate mesh sheet and the front and rear security mesh sheets with considerable movement. If a rotary tool such as an angle grinder is applied to the structure, the fencing will vibrate in an erratic manner and tend to jitter against the peripheral cutting edge of the grinder disc and may even cause the grinder disc to shatter.

Figure 6 shows the horizontal and vertical galvanised steel grid wires 8 and 9 of the security mesh of one of the security mesh sheets 3 or 4 in more detail.

The thicknesses (diameters) t1 and t2 of the horizontal and vertical grid wires are both suitably 3mm or greater, e.g. 3.5mm or greater. The thicknesses are 3.65mm in this embodiment and may be 5.6mm in other embodiments. t1 and t2 may be the same or different.

The vertical mesh spacing s1 is suitably 30mm or less, e.g. 20mm or less or 13mm or less, and in the embodiment of Figure 1 is 12.7mm. The resulting vertical mesh opening height of 12.7 - 3.65 = 9.05mm is too small for an attacker to insert his/her fingers to obtain a handhold on the mesh. Hence it is impossible to climb without a tool such as a grappling hook or ladder.

The horizontal mesh spacing s2 is suitably 100mm or less, preferably 90mm or less, most preferably 80mm or less, and is 76.2mm in this embodiment. The resulting horizontal mesh opening width of 76.2 - 3.65 = 72.55mm is too narrow for an attacker to insert a foot in order to gain a foothold on the fencing.

The ratio of the length of the long side of the mesh opening to the length of the short side of the mesh opening is 72.55/9.05 = 8.0 in this embodiment. In other embodiments this ratio is at least 2:1 , preferably at least 3:1 , most preferably at least 5:1.

The size of the mesh opening is sufficiently great in relation to the thickness of the grid wires to make the fencing substantially transparent (e.g. to CCTV cameras) even with two thick nesses of mesh.

The height of the security fence panel is more than 2m in this embodiment. Figures 7, 7A and 8 show a second embodiment of the present invention. Figure 7 shows a security fencing panel identical to that of Figures 1 to 6 except that the intermediate steel mesh sheets 60 are inclined at an angle ø to the front and rear security mesh sheets 4 and 3 in plan view, as best seen in Figures 7a and 8. The depth of the fence panel (i.e. the distance between the two security mesh sheets 3 and 4) is the same as in the first embodiment and so the intermediate sheets 6 are wider than that shown in Figure 4.

As shown in Figure 7A, the mode of connection using connectors 10 is similar to that shown in Figure 5A. Angle ø is suitably in the range of 10 degrees to 80 degrees, preferably 30 degrees to 60 degrees, most preferably 40 degrees to 50 degrees and in the embodiment of Figures 7 to 8 is 45 degrees.

As seen in Figure 8, the widths and spacing of the intermediate mesh sheets 60 are such that they extend over the entire width of the security fencing panel with no gaps between them in the width direction. Thus, there is no transverse cross section in this embodiment that does not intersect at least one intermediate mesh sheet 60. Hence any projectile directed at the fencing panel will tend either to glance off the front security mesh sheet 4 or, if it is directed orthogonally at the fencing panel will tend to be deflected by one of the intermediate mesh sheets 60 even if it penetrates the front security mesh sheet.

A security fencing panel construction in which the intermediate sheets are at an angle to the security mesh sheets will tend to be more opaque than that in which the intermediate sheets are orthogonal to the security mesh sheets, which will be advantageous in some applications. However, the increase in opacity is not as great as may be expected, as the resulting security fence panel may still be at least partially transparent.

In order to increase opacity, and to enhance the impact resistance of the construction, the thickness of the steel wires used in the security mesh sheets may be increased to 4mm or greater, for example 5.6mm. If it is necessary to limit the weight of the construction, the spac ing of the wires may be increased, for example to 20mm or greater. The thickness of the steel wires may also be reduced in order to reduce the weight of the security fence panel.

Figures 9, 10 and 11 show a third embodiment of the present invention. Referring to Figure 9, the supporting posts 2 are embedded in concrete blocks 41 and are connected by a ground- level concrete barrier 42 (Figure 10). The concrete blocks may have a height of more than 0.5m, preferably more than 0.6m. The front security mesh sheet 40 has a height H1 of more than 3m which is significantly greater than that of the rear security mesh sheet 3. Thus, only a height H2 (above ground level G) includes a double thickness of security mesh sheets. H2 is suitably more than 2m in this em- bodiment.

The supporting posts 2 carry upper extension portions on which is mounted a coil 12 of razor wire, backed by three horizontal rows 11 of razor tape or barbed wire to deter climbers. The structure is best shown in Figure 11. Other features of this embodiment (e.g. the angle of the intermediate sheets) correspond to those of either the first or the second embodiment discussed above.

A fence (e.g. a perimeter fence) can be constructed from a series of fencing panels described above, the security mesh sheets thereof being joined by the fixing plates 5 of the supporting posts 2.

The features of the embodiments and the claims herein can be combined in any practical combination.

Claims

1. A security fence panel comprising mutually confronting security mesh sheets which in use are spaced apart, the security mesh sheets being connected by intermediate sheets wherein in use the intermediate sheets are inclined to the horizontal and extend across the space between the confronting security mesh sheets.

2. The security fence panel according to claim 1 wherein the intermediate sheets are sub stantially vertical panels.

3. The security fence panel according to claim 1 or claim 2 wherein the intermediate sheets have an inclination to the horizontal in the range of 50 degrees to 90 degrees, preferably in the range of 60 degrees to 90 degrees, most preferably in the range of 75 degrees to 90 degrees.

4. The security fence panel according to any preceding claim wherein the intermediate sheets are connected sufficiently loosely to the security mesh sheets to allow movement of the security mesh sheets relative to the intermediate sheets.

5. The security fence panel according to claim 4 wherein the intermediate sheets are con nected sufficiently loosely to the security mesh sheets to allow movement of at least 2mm, preferably at least 5mm.

6. The security fence panel according to any preceding claim wherein the intermediate sheets are parallel to each other and are pivotally connected to the security mesh sheets to allow stowage of the security fence panel in a collapsed state prior to erection.

7. The security fence panel according to any preceding claim wherein the intermediate sheets are pivotally connected to the security mesh sheets by spiral connectors threaded through the mesh of the security mesh sheets.

8. The security fence panel according to any preceding claim wherein the intermediate sheets are mesh sheets.

9. The security fence panel according to claim 8 wherein spiral connectors are threaded through the mesh of the intermediate sheets and the mesh of the security mesh sheets.

10. The security fence panel according to any preceding claim wherein the security mesh sheets have horizontal mesh spacings of 100mm or less, preferably 90mm or less, most preferably 80mm or less.

11. The security fence panel according to any preceding claim wherein the security mesh sheets have vertical mesh spacings of 20mm or less, preferably 13mm or less.

12. The security fence panel according to any preceding claim wherein the security mesh sheets have substantially rectangular mesh openings wherein the ratio of the long side to the short side is at least 2:1 , preferably at least 3:1 , most preferably at least 5:1.

13. The security fence panel according to any preceding claim wherein the security mesh sheets are formed from wire having a diameter of 3mm or greater, preferably 3.5mm or greater.

14. The security fence panel according to any preceding claim wherein the intermediate sheets are substantially orthogonal to the security mesh sheets.

15. The security fence panel according to any of claims 1 to 13 wherein in plan view, the intermediate sheets are inclined at an angle to the security mesh sheets.

16. The security fence panel according to claim 15, wherein in plan view, the intermediate sheets are inclined at an angle to the security mesh sheets in the range of 10 degrees to 80 degrees, preferably 30 degrees to 60 degrees, most preferably 40 degrees to 50 de grees.

17. The security fence panel according to claim 15 or claim 16, wherein any transverse cross-section taken orthogonally between the two security mesh sheets over the majority of the length of the panel intersects at least one intermediate sheet.

18. The security fence panel according to any preceding claim wherein the height of the security mesh sheets is at least 1.7m, preferably at least 1.9m.

19. The security fence panel according to any preceding claim having barbed wire, razor wire, razor tape or the like disposed along its upper edge region.

20. The security fence panel according to any preceding claim wherein security mesh sheet on one side of the security fence panel is higher than security mesh sheet on the other side of the security fence panel.

21. The security fence panel according to any preceding claim which has a rating under ASTM F2781-10 (Table 2) of M5 or higher, preferably M10 or higher, more preferably M15 or higher.

22. The security fence panel according to any preceding claim which has a rating under ASTM F2781-10 (Table 2) of A5 or higher, preferably A10 or higher, more preferably A15 or higher.

23. Security fencing comprising at least one security fence panel according to any preced ing claim, further comprising supporting posts, wherein the security fence panel is secured to the supporting posts by tamper-resistant fastenings.

24. A kit of parts for security fencing according to claim 23, the kit comprising a plurality of supporting posts and a plurality of security fence panels as defined in any one of claims 1 to 22.

25. A method for arranging a security fencing according to claim 23 comprising fixing the security fence panel to the supporting post such that the intermediate sheets can move relative to one or both of the security mesh sheets.