Abstract:
An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     The United States Government has certain rights in this invention pursuant to Department of Energy Contract No. DE-AC04-94AL85000 with Sandia Corporation. 
    
    
     FIELD OF THE INVENTION 
     The invention generally relates to vehicle barriers of the modified Normandy type. The invention further relates to vehicle barriers having access delay features incorporated into their construction, thereby delaying and/or preventing attempts by an adversary to defeat, compromise, or remove the barrier. 
     BACKGROUND OF THE INVENTION 
     A need exists for vehicle barriers that prevent unauthorized vehicular access to secure and/or high value facilities such as embassies, nuclear power generating stations and military installations. Barriers developed for these applications are often tested using guidelines established by the standard: ASTM F 2656-07 Standard Test Method for Vehicle Crash Testing of Perimeter Barriers. Vehicle barriers designed to meet or surpass this standard are intended to prevent a vehicle such as a medium sized truck, perhaps equipped with an explosive device, from ramming through the barrier. Such barriers can include for example, steel or concrete monolithic structures and can be subject to attack (e.g. defeat, compromise or removal) by an adversary equipped with simple thermal, explosive and/or mechanical tools, such as a cutting torch, powered saw, diamond saw, abrasive cut-off wheel, explosive device and shaped charge. There is therefore an unmet need for a vehicle barrier incorporating access delay features that can not only stop an unauthorized vehicle in a ramming attack, but additionally can prevent or delay an adversarial attack with thermal, explosive and/or mechanical tools. The present invention provides substantial access delay features in a vehicle barrier, without compromising the barriers&#39; ability to physically stop an impacting vehicle. Embodiments of the present invention can incorporate multiple defeat resistant, access delay elements. Embodiments of the present invention additionally provide for minimal visual obstruction of their setting and do not provide hiding places for adversaries, which can be problematic in the deployment of massive concrete walls or devices commonly known as “Jersey” barriers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic illustration of an embodiment of an access delay vehicle barrier, according to the present invention. 
         FIG. 2  is a schematic detail illustration of an embodiment of a free standing vertical support formed by crossed I-beams, according to the present invention. 
         FIG. 3  is a schematic detail illustration of an embodiment of a vertical fixed post support proximal to a horizontal barrier member, according to the present invention. 
         FIG. 4  is a schematic cross-sectional detail of an embodiment of a horizontal barrier member, according to the present invention. 
         FIG. 5  is a schematic cross-sectional detail of another embodiment of a horizontal barrier member, according to the present invention. 
         FIG. 6  is a schematic illustration of another embodiment of an access delay vehicle barrier, according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a schematic illustration of an embodiment of an access delay vehicle barrier, according to the present invention. In this exemplary non-limiting embodiment, vehicle barrier  100  includes a horizontally disposed barrier member  102  (incorporating access delay features as discussed below) supported on free standing supports  104  (see detail  FIG. 2 ) that serve to maintain the barrier member  102  above a surface  112  (e.g. the local terrain) by a stand-off distance “S”. In this exemplary embodiment, a stand-off distance “5” approximately equal to thirty inches was used. Supports  104  are said to be “free standing” in that they are not intentionally embedded, buried or set into the surface (e.g. the earth, paved roadway etc.) but merely rest on the surface  112 . In this manner, a vehicle impacting the barrier  100  can cause lateral displacement of the barrier member  102  relative to the surface  112  by the action of sliding the free standing supports  104  along the surface. Free standing supports  104  can be fixedly connected (e.g. by welds, threaded connectors etc.) to the barrier member  102 . 
     In addition to the free standing supports  104 , vehicle barrier  100  can include fixed post supports  106  that are disposed proximal to (e.g. can be contacting) but may or may not be not fixedly connected to the horizontal barrier member  102  (see detail  FIG. 3 ). Fixed post supports are intentionally embedded into the surface  112 , for example driven into the earth or set in concrete post-holes. In one exemplary embodiment, free standing supports  104  were disposed at approximately eight foot intervals along the horizontal barrier member  102  and fixed post supports  106  were disposed at approximately fifty six foot intervals along the horizontal barrier member  102 . In applications of the vehicle barrier  100 , the number and spacing of fixed  106  and free standing supports  104  can be adjusted as desired to meet the needs of the particular application. In particular, the fixed post supports  106  are designed and engineered to allow gradual deceleration of the impacting vehicle. Such gradual deceleration limits the amount of vehicle damage and deformation which could lead to continued travel of the load (e.g. explosives) into a protected area. In order to accomplish this goal the material, number, size, spacing and anchoring of the vertical posts can be modified to tailor the vehicle barriers&#39; response to an applications&#39; perceived threats. 
     Vehicle barrier  100  can additionally include anchor members  108  generally disposed at either end of a horizontal segment of a barrier member  102  to fixedly anchor the barrier member  102  to the surface  112 . Anchor members  108  can include concrete blocks embedded into the surface  112  (e.g. buried or formed and poured in the earth) and can be tied via steel cables  110 , rods or struts to the barrier member  102 . Anchor members  108  can as well include anchoring devices that can be driven or screwed into the earth or set in concrete embedments, or can additionally include fixed post supports (such as  104 ) disposed at the ends of a barrier member  102 . Anchor members can additionally include access delay features as described below. As illustrated in  FIG. 1 , embodiments of vehicle barriers with access delay features provide little visual obstruction of the setting they are placed into, and/or provide few if any hiding places for adversaries. 
       FIG. 2  is a schematic detail illustration of an embodiment of a free standing vertical support formed by crossed I-beams, according to the present invention. In one exemplary embodiment, a free standing support  104  can be constructed of W6x15 ASTM A992 wide flange fabricated into “X” shaped supports. Flange members  1041  and  1042  can be crossed at any angle of convenience (e.g. 45 degrees in this illustration) and can be connected together by welding (at areas generally denoted by “W 1 ”) or through the use of threaded fasteners for example. Horizontal barrier member  102  can be set into the “V” created by the crossed flange members of support  104  and can further be connected to the support  104  by welding (at areas generally denoted by “W 2 ”) or through the use of threaded fasteners. As noted above, free standing supports  104  are not intentionally embedded into the surface  112 , although some natural settling of the supports  104  into the surface  112  can occur for example, due to the weight of the horizontal barrier member  102 , without impacting the practice of the invention. 
       FIG. 3  is a schematic detail illustration of an embodiment of a vertical fixed post support proximal to a horizontal barrier member, according to the present invention. In one exemplary embodiment, fixed post supports  106  can be constructed of W6x15 ASTM A992 wide flange members spaced fifty six feet apart on center and can be embedded fifty six inches into the surface  112 . Fixed post supports  106  can be driven into the earth, or can as well be embedded in compacted soil or concrete embedments. Fixed post support  106  is disposed proximal to (e.g. can be touching) Horizontal barrier member  102  and may or may be not be fixedly connected to the horizontal barrier member  102  (e.g. by welding or threaded fasteners). Fixed post support  106  can provide lateral support to the barrier member  102  but may or may not provide vertical support to the barrier member. 
       FIG. 4  is a schematic cross-sectional detail of an embodiment of a horizontal barrier member, according to the present invention. In this exemplary embodiment, horizontal barrier member  102   a  can be constructed of a W6x25 ASTM A992 wide flange interior steel reinforcing member  118  inserted into an 8×8×½ inch ASTM A500 Grade B square tube exterior steel casing  122  with access delay members  120  inserted between the web of the wide flange  118  and the square exterior casing  122 . In this exemplary embodiment, the access delay members  120  consisted of wooden 2″×6″ dimensioned lumber. It has been found that the inclusion of the access delay members  120  within the barrier member  122  impairs and delays an adversary that may attempt to remove or defeat a barrier by use of mechanical, thermal or explosive means. For example a cutting tool (e.g. cut-off wheel) that might be effective in cutting through the steel casing  122  would be substantially ineffective in cutting through the wooden access delay members  120 . Similar analyses hold true for thermal and explosive tools. Access delay members  120  could as well comprise concrete and/or polymeric members. Additionally, reactive materials that smoke or emit noxious fumes when heated or attacked can be used as well. Hardened objects/materials may be embedded in this area to further frustrate cutting attacks. 
       FIG. 5  is a schematic cross-sectional detail of another embodiment of a horizontal barrier member, according to the present invention. In this exemplary embodiment, horizontal barrier member  102   b  can be constructed of three inch diameter A36 steel round stock as the interior reinforcing member  114  inserted into an 8×8×½ inch ASTM A500 Grade B square tube exterior steel casing  122 . In this example, access delay members  116  comprise dimensioned lumber inserted within the casing  122 , between the casing  122  and the interior reinforcing member  114 . As above, access delay members  116  could as well comprise concrete and/or polymeric members. The interior reinforcing member  114  could as well comprise a solid member of square cross-section, a steel cable, chain, laminates of several materials, or any other tensile force resistant medium. 
       FIG. 6  is a schematic illustration of another embodiment of an access delay vehicle barrier, according to the present invention. Access delay vehicle barrier  130  includes a horizontally disposed barrier member  102  supported above a surface  112  by free standing supports  104  and may include fixed post supports  106 . As described above, barrier member  102  can include multiple access delay features. Additionally, vehicle barrier  130  includes a number of vertical barrier sections  128  (e.g. posts and/or pipes) connected (e.g. welded or attached via threaded fasteners) to the barrier member  102  and extending vertically “upward” from the barrier member  102 . It can be beneficial in certain applications to include the vertical barrier sections to prevent for example, small vehicles such as all-terrain vehicles (“ATVs”) or motorcycles from “jumping” over a vehicle barrier. Additional vertical barrier sections  128  could be connected to the barrier member to extend “downwardly” where desired. 
     In assembling horizontal sub-sections to form embodiments of a length of horizontal barrier member, sub-sections of the interior steel reinforcing members can be welded together using backing plates as desired and by connecting sub-sections of exterior steel casing again using backing plates where desired. The figures cited above illustrate barrier members having a square tube exterior casing but the use of other shapes, such as round or triangular could be employed as well with no impact to the practice of the invention. It should also be noted that the interior reinforcing members illustrated included I-beams and round stock, while virtually any shape could be selected as convenient for an application, as well as steel cables, chain, laminates of several materials, or any other tensile force resistant medium as noted above. In some applications, it may be desirable to include a plurality of horizontal barrier members having access delay features, in the construction of a vehicle barrier. 
     The above described exemplary embodiments present several variants of the invention but do not limit the scope of the invention. Those skilled in the art will appreciate that the present invention can be implemented in other equivalent ways. The actual scope of the invention is intended to be defined in the following claims.