Attach_1_GASNT_Fencing_Details.docx

Fence Materials. Fence, IDS Sensored Platforms shall use materials conforming to Federal Specification RR-F191 series and the following specified components:

Chain Link Fabric. All fence fabric shall comply with Federal Specification RR-F191 series (Chain Link Fence Fabric) with standard 2 square mesh, 9 gauge aluminized steel wire, minimum 7 foot height, one selvage is knuckled, the other, twisted. The twisted selvage should be at the top of the fence, with the knuckled selvage at the bottom. All fence components shall be black-vinyl coated, as possible. Components to be painted to match shall be submitted to the Government for prior approval.

Posts and Rails. Shall be round components and comply with Federal Specification RR-F191 series (Chain Link Fence Posts, Braces and Rails). Tables 3 and 4 provide required fence component sizes and strengths. Gateposts should be designed to support the gates proposed. Minimum requirements are given in FS RR-F191/3D. Gateposts supporting hardware for swing, rolling, cantilever or lift gates must also be isolated from fabric carrying posts. Gateposts shall be a minimum of 4” outer diameter (O.D.) and be sized according to Table 3. Corner, end and pull posts shall be of adequate height to accept barbed wire terminations. The overall height of these posts, when fitted with cap dome and anti-tamper spike shall be equal to the height of the line posts with the vertical outriggers. The fence system shall be designed and installed so that the distance between corner, end and pull post in any continuous fence run, do not exceed 100 meters.

TABLE 4. Physical Dimensions and Properties for Fence Pipe

Fittings. All post caps, barbed wire outriggers, tension/stretcher bars (3/16" x 3/4"), brace bands, tension bands, hinges and other fittings shall be pressed steel and galvanized. Aluminum fittings are not authorized.

Tension Wire. Three (3) tension wires shall be used in the standard fence design. The wires shall be stretched taut to help support the tension of the fence fabric; in order to achieve success in these tests tension wires shall be tensioned to 500 pounds. The top tension wire shall be approximately 7.5 inches below the top of the fabric. The other two tension wires shall be located at approximately 31 and 56½ inches down, respectively, from the top of the fence fabric. All tension wires shall be galvanized 7 gauge hardened steel spring wire. Tension wires shall be connected to corner, end and pull posts and will be limited to zone length. One end of each wire shall be secured to an appropriately sized brace band and the other with a turnbuckle. The tension wires shall be connected to the brace bands and turnbuckles using double barrel swages. If tension wires are spliced, swages shall be used.

Fasteners. Fabric shall be firmly secured to line posts and rails with 9 gauge galvanized steel tie wire. Firmly secure fabric to tension wires with 9 gauge aluminized steel wire ties. The use of hog rings or aluminum wires of any gauge are not permitted.

Footings. All footings shall be 48 inches deep.

Concrete. The strength of all concrete footings shall be no less than 3000 psi. The concrete shall be mixed, transported, handled and placed in accordance with Unified Facilities Guide Specification, Division 03 Concrete, Section 03 30 00 Cast-In-Place Concrete. The top of the post-footings shall be finished so that at the post the concrete is 1/2” to 1” above grade and sloped 1/2" down to the footing edge.

Outriggers. The IDS sensor platform shall be configured with vertical outriggers and shall have no top rail. Vertical outriggers require fabrication to include caps to fit the fence posts, breakaway cutouts, support-notches for barbed wire, and an anti-climbing spike. An example of an outrigger is shown in Figure 47 and fabrication dimensions can be provided upon request. Vertical outriggers will be 37 ½” measured from the top of the post cap with an anti-climb spike extending another 5” at the top. Corner, pull, end and gate posts shall be equipped with top cap domes with an anti-climb spike.

Barbed Wire. The barbed wire shall be 4-point, 15.5 gauge high tensile barbed, with 5" Barb Spacing and a minimum breaking load of 950 lbs. The barbs located within 4” of the outriggers shall be removed. Barbed wires will pass through the vertical outrigger notches and be connected to corner, end or pull posts and will be limited to zone length. Barbed wire shall be secured to pull, end, and corner posts using brace bands with a ratchet tensioner at one end and a turnbuckle at the other (Reference FPB-ASSY-SC02-001R0C0 SHEET 4). The barbed wire shall be secured using swages. If barbed wire requires splicing, swages shall be used. All barbed wire shall be tightened to 50-70 pounds upon installation and then adjusted appropriately at sensor installation. After the barbed wire is appropriately tightened for the sensor, the barbed wire shall be secured to all the vertical outriggers with 6” long, double-looped, 18 gauge stainless steel twist ties with the twists on the secure side of the outriggers.

General Installation Requirements. Installation standards for fences used to support security sensors exceed those required for standard chain link or cyclone fence installation. Installers are expected to comply with detailed instructions and testing requirements to create successful sensor platform fences.

Fabric Attachment. Fabric shall be installed twisted selvage up and knuckled selvage down. The fabric shall extend below the bottom rail enough to have at least the first row of complete diamonds partially below the bottom rail and shall not touch the grade or concrete footings. It will be anchored to prevent intruders from lifting the fabric and creating an opening greater than 5”. Fabric shall be securely fastened using materials specified in 2.6.3.5 according to the following spacing:

All ties will be twisted at least three (3) complete turns and be terminated on the secure (interior) side of the fabric. The ties shall be twisted to restrict any movement of the fence fabric at the contact point of the tie, fence fabric, tension wire, posts and rails. If possible, ties will cross two pickets at a knuckle. If not, the picket closest to the pipe or wire will be tied. The ties on line posts shall be placed 14” O.C. and a tie shall be placed within 4 inches from the top and bottom of the fabric. Fence fabric to line post wire ties shall be installed so that twisted ends are parallel to the fabric. All other fabric wire ties shall be installed so that the twisted ends are perpendicular to the fabric.

Fence Posts and Rails. Bottom rails are required with all sensored fences. Sensored fences do not contain a top rail. The top rail must be removed from existing fences. All bottom rails shall be a single continuous piece from post to post braced with in-line bottom rail clamps (boulevards) except at corner and end posts where bottom rail end caps with brace bands will be used. Post caps and outriggers shall be tack welded or riveted to posts to prevent movement. Also brace bands at corner, pull, end, and line posts shall be tack welded prior to fabric placement to prevent bands from shifting. Welds shall be corrosion treated with galvanized paint. Brace assemblies are required to counteract lateral forces and shall be located at each corner, end and pull post. In some cases, two braces will be required in a single panel. The configuration and installation shall be in such a way that the test requirements in paragraph 2.6.5 are met. All fence bolted hardware shall have the threaded ends on the secure side of the fence to prevent tampering.