The present disclosure relates to a surface mount security barrier. Aspects of the invention relate to a surface mount security barrier, a security mount barrier system, a security fence, and to a method of making a surface mount security barrier.
With the increasing incidence of terror attacks using the weaponization of vehicles by driving them at crowded pedestrian areas, there is an increasing need for barriers that prevent or hamper vehicular passage.
In general, security barriers, or crash barriers, the main purpose of which is to prevent the passage of vehicles, are widely known in the art and have many applications. Common applications are for bordering dangerous sections of roads, providing a central separation between lanes of traffic moving in opposite directions, and around secure areas, for example around the entrance to airports or the like.
Such barriers generally include some form of underground footing which is either integral with an above ground section of the barrier or to which an above ground section of the barrier is attached. While these provide an adequate solution for permanent areas of risk where the cost and disruption of installing them is justified, they do not provide a good solution where a temporary measure is needed. Examples of where a temporary measure may be needed are at intended permanent sites prior to the installation of a permanent solution and at seasonal or short-term events, for example music festivals, Christmas markets or the like.
It is an aim of the present invention to provide a security barrier that can easily be placed on top of the existing ground surface at a required location without the need for any excavation or specific surface preparation.
Aspects and embodiments of the invention provide a security barrier, a security fence, and a method of manufacturing a security barrier, as claimed in the appended claims.
According to a first aspect of the invention there is provided a surface mount security barrier, the barrier comprising: a non-metallic matrix supporting and substantially encapsulating metallic ballast, wherein said security barrier has a mass in excess of 6 tonnes and a ratio of metallic ballast to non-metallic matrix in excess of 1.5:1 by mass. Optionally the ratio of metallic ballast to non-metallic matrix may be 2:1 by mass.
The non-metallic matrix may comprise concrete.
The surface mount security barrier may have a bottom face and a top face and the metallic ballast may comprises a first layer of one or more pieces of metallic ballast located between the bottom face and the top face. Optionally the metallic ballast may comprise at least a second layer of one or more pieces of metallic ballast located above the first layer and between the bottom face and the top face. The first and/or the second layer of one or more pieces of metallic ballast may comprise a plurality of pieces of metallic ballast.
Optionally the matrix may extend between said pieces of metallic ballast isolating them from one another.
The surface mount security barrier may comprise one or more lifting points embedded in therein. The lifting points may comprise two or more box sections extending therethrough and opening on opposing surfaces thereof. The box sections may extend through the matrix between the first layer of metallic ballast and the second layer of metallic ballast. A bench or seat may be attached to one or more sides thereof, optionally the bench or seat may be attached to said lifting point. By using the existing lifting point, a secure anchorage is provided for the seat or bench without the need for drilling holes or providing additional fixing structure.
The metallic ballast may comprises steel or lead, although it will be appreciated other metals having a density higher than the matrix may be used. In various arrangements the metallic ballast comprises one or more of: one or more pieces of metallic ballast, each said piece comprising a single elongate section of metallic billet; one or more pieces of metallic ballast, each said piece comprising a plurality of elongate section of billet; one or more pieces of metallic ballast, each said piece comprising a plurality of pieces of metal, especially metal balls or small pieces of scrap metal, bound together by a binder material.
Optionally the mass of the metallic ballast is biased towards a bottom face of the security barrier. In an arrangement the first layer of at least one piece of metallic ballast is located in a lower 50% of the height of the security barrier. Where the surface mount security barrier comprises a second layer of ballast the first layer of at least one piece of metallic ballast comprises in excess of 60% of the metallic ballast, optionally in excess of 70% or 80%. By biasing the mass of the ballast, which has a greater density than the matrix, towards the bottom of the security barrier the stability of the barrier is increased under impact. This not only enables a smaller overall size of barrier to be used to meet the impact test requirements but also reduces the likelihood of the barrier rolling when impacted at speeds above its rated test speed.
In one arrangement the metallic ballast may comprise a plurality of small pieces of metallic ballast dispersed throughout the matrix.
A rebar cage may be embedded within the matrix below the surface of said security barrier. This assists the matrix in retaining its integrity under impact. Preferably the rebar cage surrounds said ballast within said matrix.
In one embodiment the security barrier may comprise a plurality of feet extending from a bottom surface thereof. Optionally, the feet may be formed as part of the rebar cage and when the security barrier is formed, the feet may project outwardly from a lower surface thereof. The feet may project from the lower surface of the security barrier for a distance of 1 to 10 mm. In use, when placed on a hard surface, due to the weight of the security barrier, the feed will, under impact, act as “teeth” and provide very high pressure contact points which, if the block moves as a result of an impact, will dig into the surface on which it is situated, further impeding the movement of the security barrier.
According to another embodiment of the invention there is provided a surface mount security barrier system comprising a surface mount security barrier as described above and an anti-skid plate beneath said surface mount security barrier and wherein the anti-skid plate has a plurality of metal feet extending downwardly therefrom. The anti-skid plate may comprise a steel tray in which the surface mount security barrier is located. The tray may have upstanding sides within which the security barrier fits, and a plurality of feet extending downwardly from the plate at a distance of 1 to 10 mm. When located in the anti-skid plate the security barrier may be retained therein by the application of a grout between the security barrier and the anti-skid plate. Under impact the anti-skid plate will function in the same manner as the projecting feed described above.
Optionally the surface mount security barrier is substantially rectangular, although it will be appreciated that other shapes may be used. The surface mount security barrier may have chamfered or radiused edges. This helps in preventing damage to the corners of the security barrier when being lifted of moved.
The surface mount security barrier may have a mass in the range of 7.5 tonnes and 8.5 tonnes and optionally may comprise at least 5.5 tonnes of metallic ballast.
The security fence may be provided with a post footing cast substantially centrally therein and opening on an upper surface thereof for receiving a security barrier post. The post footing may be as described in GB 2511273 and may receive a spring steel impact post also as described in GB 2511273.
The surface mount security barrier may be provided with a plurality of fence post holes extending downwardly from the top surface thereof. The holes may be formed by providing sections of steel tube at each location and casting the matrix around the steel tubes such that they become embedded therein and opening on the upper surface thereof. In use fence posts may be inserted to one or more of the holes to which ancillary barriers may be added. In one embodiment posts may be provided on adjacent security barriers and a fence or openable gate may extend therebetween.
Optionally the surface mount security barrier may further comprise a security post footing extending downwardly into a top surface thereof, said post footing for receiving, in use a security post.
According to another aspect of the invention there is provided a security fence comprising a plurality of surface mount security barriers as described above, a fence post located in one or more fence post holes in each said surface mount security barrier, and at least one fence panel attached to fence posts of adjacent surface mount security barriers.
Another aspect of the invention provides a security fence comprising a plurality of surface mount security barriers each having a security post footing embedded therein, a spring steel security post located in the security post footing of adjacent surface mount security barriers and one or more metal wire extending between the security posts of said adjacent surface mount security barriers.
According to a further aspect of the invention there is provided a method of manufacturing a security barrier, the method comprising: placing a first piece of a rebar cage, comprising at least a lower face of said rebar cage, adjacent a lower surface of a mould; placing a first layer of at least one piece of metallic ballast above said lower face of the rebar cage; placing at least two lifting points within the mould; placing a second piece of a rebar cage within the mould, the second piece of the rebar cage comprising the remaining faces thereof; and pouring concrete into the mould to substantially encapsulate said metallic ballast and rebar cage.
Where the security barrier is intended to have projecting feet, the projecting feet may be formed integrally with the first piece of the rebar cage and, prior to placing the first piece of rebar cage adjacent the lower surface of the rebar cage a sheet of polyurethane foam may be placed into the mould so as to cover the lower surface thereof. The polyurethane foam may be a high-density polyurethane foam that has a high crush resistance. Small holes may be provided in the polyurethane foam sheet for the feet to extend into or, alternatively sufficient force may be brought to bear on the first piece of the rebar cage such that the feet each punch into the polyurethane foam sheet, thereby to create their own holes. For example, the mass of the metallic ballast may bear directly on the first part of the rebar cage so as to create sufficient point pressure on the feet that they punch into the polyurethane foam sheet. Alternatively, the first piece of the rebar cage may be struck, for example with a mallet, above each foot so as to drive them into the polyurethane sheet. It will be appreciated that other sheet materials apart from polyurethane could be used, the functional requirement of the sheet being such that the point pressure applied to the feet is sufficient to drive them into the sheet material, whereas the even loading of the concrete when added to the mould is not sufficient pressure to crush the sheet material to such a degree that the feet do not project once the security barrier is formed.
Placing a first layer of at least one piece of metallic ballast above said lower face of the rebar cage may comprise placing a first layer of pieces of metallic ballast above said lower face of the rebar cage. Placing at least two lifting points within the mould may comprise placing two lengths of box section above the first layer of at least one piece of metallic ballast.
The method may also comprise placing a second layer of at least one piece of metallic ballast above the first layer of at least one piece of metallic ballast. Placing a second layer of at least one piece of metallic ballast above said first layer may comprise placing a second layer of pieces of metallic ballast above the first layer of at least one piece of metallic ballast.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
A security barrier, also known as a crash barrier, in accordance with an example embodiment of the present invention is described herein with reference to the accompanying
With reference to
The security barrier 10 has an internal structure, as shown in
Referring to
The interior structure of the security barrier 10 comprises a first and second layer of pieces of metallic ballast which are in the form of steel blocks 18 located between a top face 20 and a bottom face 22 of the security barrier 10. In the embodiment shown the first layer comprises a first array of blocks and the second layer comprises a second array of blocks. The steel blocks 18 may comprise solid pieces of steel billet or may each comprise a plurality of strips of steel, placed adjacent one another or attached together. In the example embodiment the steel blocks 18 have a mass of 6000 kg (+/−10%). This results in a ratio of metallic ballast to matrix of approximately 3:1 (excluding the rebar cage). It will be appreciated that a lower ration of ballast to matrix may be used from 1.5:1 upwards, for example the ration may be at least 1.75:1, at least 1.8:1, at least 2:1, or at least 2.25:1, or at least 2.5:1. It will be appreciated that increasing the ratio of metallic matrix to non-metallic aggregate increases the average density of the barrier, thereby enabling the same total mass to be achieved in a smaller space envelope, allowing for a more discreet and practical barrier without reducing its effectiveness. The pieces of metallic ballast forming the first layer have a greater mass than the pieces of metallic ballast forming the second layer. The first layer of steel blocks may account for in excess of 60% of the mass of the metallic ballast, optionally in excess of 70% or 80%. This biasing may be achieved by using different sizes of pieces of metallic ballast in each layer, a different number of pieces of metallic ballast in each layer, or different densities of metallic ballast (i.e. different metals or alloys) in each layer. By biasing the mass of the ballast, which has a greater density than the matrix, towards the bottom of the security barrier the stability of the barrier is increased under impact.
The steel blocks 18 are substantially surrounded by a rebar cage 24 that extends below, above and around the array of steel blocks 18 and substantially adjacent to, but beneath, the respective exterior surfaces of the cast concrete that surrounds the interior structure 16. Although shown as a rectangular array, the steel blocks 18 may alternatively be arranged in a linear array, or irregularly. It will also be appreciated that although shown as rectangular blocks, alternative shaped pieces of metallic ballast can be used as described in more detail below. The steel blocks 18 are arranged in spaced relationship to one another such than when encased in the cast concrete 14, the concrete passes around and between them in a continuous structure.
In the example embodiment a rebar cage 24 as shown in
A first layer of the steel blocks 18 is then located in the first part 26 of the rebar cage in a linear array, and a first two lengths of box section 38 are laid on top of them extending across the rebar cage 24 and protruding slightly from each side thereof.
The two lengths of box section 38 are dimensioned so that they are the same length as the width of the formed security barrier 10 and are located on top of the first layer of steel blocks 18 substantially perpendicular thereto. Optionally, a second two lengths of box section 44, which may be substantially identical to the first two lengths of box section 38, may be located below the lower face of the rebar cage. These second two lengths of box section 44, may form additional lifting points and/or additional fixing points for seats, benches or other furniture. The length of the first two lengths of box section 38 are such that they open onto opposing faces of the formed security barrier 10. A cover is placed over the end of each length of box section 38 to prevent concrete entering therein during the casting of the concrete matrix 14 around the ballast and rebar. The cover may be a bespoke cover or may for example simply be a temporary cover made of tape. After the security barrier 10 is cast the covers are removed and either disposed of or used in the fabrication of further security barriers. The second two lengths of box section 44 may be arranged in a similar manner.
A second layer of steel blocks 18 is then located above the first layer substantially parallel to the first layer and the remaining two faces being a top face 40 (
The interior structure 16 is then encased in concrete as described above. The arrangement of the ballast as described above ensures that when the concrete is added it is able to extend between the pieces of ballast thereby substantially isolating them from each other. It also ensures that the concrete matrix is one continuous piece of concrete.
Referring to
At 102 the second two lengths of box section 44 are placed on the lower face of a substantially rectangular mould. The mould (not shown) comprises a bottom surface with four side pieces pivotally connected thereto such that they can be pivoted upwards to form a rectangular mould.
At 104 the first part 26 of the rebar cage 24 is placed adjacent a lower surface of the mould over the top of the second two lengths of box section 44.
At 106 a first linear array of steel bars 18 is placed on top of the first part of the rebar cage.
At 108 the first two lengths of box section 38 are placed above, optionally on top of, the first linear array of steel bars 18 substantially perpendicular thereto. Either prior to placement or after placement a cover is placed over the ends of at least each of the first two lengths of box section 38 and optionally over the ends of the second two lengths of box section 44.
At 110 a second linear array of steel bars 18 is placed on top of the first two lengths of box section 38, substantially parallel to the first linear array of steel bars 18.
At 112 the remaining faces of the rebar cage 24 not forming part of the first part 26 are added and fixed in place.
At 114 the mould is closed by raising the side pieces and securing them in place. It will be appreciated that this step is optional and may not be needed depending on the mould design.
At 116 concrete is added to the mould such that it fills all the spaces between the steel bars 18, the rebar and the lengths of box section 38, 44, and is left to solidify.
A security barrier 10 designed and manufactured according to the example embodiment was tested and passed the BSI IWA14.2013 collision test. In the test the security barrier 10 was placed on top of the test surface (flat concrete) without any attachment thereto or any foundations. A 7.5 tonne truck was collided with the security barrier 10 travelling at 64 kph (40 mph) and was stopped in its tracks. The security barrier 10 was impacted centrally on its two meter long face. It did not roll or spin and remained intact.
Referring now to
In order to manufacture the security barrier 10a the process described above in relation to
Once the security barrier 10a has been cast and has hardened, after it is removed from the mould the polyurethane foam sheet 46 is removed from the lower surface thereof. Rubber or plastic caps (not shown) can then optionally be fitted over the projecting metal feet 36. In use this allows the security barrier to be positioned and repositioned by lifting and moving, onto surfaces without the feet causing damage. If, however, in use the security barrier 10a is struck, e.g. by a vehicle, with sufficient force to move it the pressure on the feet 36 will result in the caps being broken or torn off allowing the metal feet 36 to dig into the surface and further impede movement of the block.
Although the manufacturing method described hereinabove relates to the use of a polyurethane sheet 46, it will be appreciated that any suitable sheet material could be used. For example, if a sheet with premade holes is to be used then the sheet material could be a sheet of wood, for example. If, on the other hand, the feet are punched into the material then any material that will allow penetration of point pressure applied to the feet 36 but will substantially not crush under the even loading of the concrete when added to the mould, may be used. In addition, a thin sheet, for example a plastic sheet, may be applied between the sheet material and the concrete to prevent adhesion of the concrete to the sheet material to facilitate easy removal.
Referring now to
Referring to
This design enables a fence to quickly be erected on the security barriers 10 that can then provide a single, or double, pedestrian barrier as well as a vehicular barrier. Although described herein as supporting fence panels 68 it will be appreciated that the fence posts 57 or the support posts 60 ay be used to support other security enhancements, for example a fence panel may have therein or may be replaced with an openable gate to selectively allow, for example, pedestrian access past the security barrier. In addition to the fence posts, spring steel security posts 64 are provided in the embedded post footings 54 and a plurality of wires 66 as described in WO 2015/033100 are attached between the security posts 64 of adjacent security barriers, thereby further inhibiting vehicular passage, in particular potentially allowing for a greater spacing between the security barriers.
Referring to
It will be appreciated that the embodiments described herein are given as examples of the invention and that modifications may be made which are within the scope of the invention which is defined by the claims. In one alternative embodiment the metallic ballast may be an alternative metal to steel, for example it may be any metal having a similar or greater density. The metallic ballast may be provided in an alternative form to steel bars. In one embodiment the metallic ballast may comprise small pieces of scrap metal (e.g. steel), for example small metal discs (or similar shape) that are produced as scrap from the punching of holes in sheet metal. The small pieces may be set in a binder to hold them together, for example cement or a resin binder. Alternatively, they may be placed in containers, e.g. sheet metal troughs. In another alternative arrangement the ballast may comprise irregular shaped pieces of metal. In another embodiment the ballast may comprise small pieces of metal, for example metal shot, metal discs, or the like, mixed with the concrete prior to casting the security barrier.
It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.
Number | Date | Country | Kind |
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1714029.4 | Sep 2017 | GB | national |
1720790.3 | Dec 2017 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/073410 | 8/30/2018 | WO | 00 |