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|Chain link fence for Security:
Chain Link Fence Manufacturers Institute Security Fencing Recommendations
Chain link fencing has been the product of choice for security fencing for over 60 years because of its strength, corrosion resistance, "see thru capabilities", ease of installation, versatility, variety of product selection and value. A chain link fence is one of the primary building blocks for a facility's perimeter security system.
The physical security barrier provided by a chain link fence provides one or more of the following functions:
- Gives notice legal boundary of the outermost limits of a facility
- Assists in controlling and screening authorized entries into a secured area by deterring entry elsewhere along the boundary.
- Supports surveillance, detection, assessment, and other security functions by providing a zone for installing intrusion detection equipment and closed-circuit television (CCTV).
- Deters casual intruders from penetrating a secured area by presenting a barrier that requires an overt action to enter.
- Demonstrates the intent of an intruder by their overt action of gaining entry.
- Causes a delay to obtain access to a facility, thereby increasing the possibility of detection.
- Creates a psychological deterrent.
- Reduces the number of security guards required and frequency of use for each post.
- Optimizes the use of security personnel while enhancing the capabilities for detection and apprehension of unauthorized individuals.
- Demonstrates a corporate concern for facility security
- Provides a cost effective method of protecting facilities
Chain link fence enhances the goals of good security planning. In-depth security planning takes into consideration the mission and function, environmental concerns, threats, and the local area of the facility to be secured. This can be translated into an A-B-C-D method that points out the values of chain link fencing to a security program.
- AIDS to security. Chain link fencing assists in the use of other security equipment, such as the use of intrusion detectors, access controls, cameras, etc. Chain link fences can be employed as aids to protection in an exterior mode or an internal protected property, as a point protection, and for general protection as required.
- BARRIERS for security. These can be buildings, chain link fences, walls, temporary checkpoints, etc.
- CONTROLS support the physical security chain link fences and barriers, such as an access control system tied into vehicle gates and pedestrian portals, various level identification badges and temporary badges, security escorts, and internal procedures.
- DETERRENTS such as a chain link fence, guards, lighting, signage, and checkpoint control procedures are a few of the deterrents that ensure intruders will consider it difficult to successfully gain access.
When properly used, the aspects of the A-B-C-D method reinforce and support each other. Thus a chain link fence is also a deterrent, and a barrier, if need be. By combining A-B-C-D, sufficient obstacles are created to prevent an intruder from obtaining information that is being worked on during the day in the controlled access area and then is protected at night, weekends, and holidays through the implementation of the security in-depth concept.
More importantly, keep in mind that a chain link fence is the common denominator of the A-B-C-D system and will reduce overall risk, secure the environment, and reduce security costs if designed and installed properly. However, believing that a fence will eliminate all illegal access is not prudent. A fence system will only delay or reduce intrusion.
In order to ensure the effectiveness of the facility security fence program, it is recommended that a maintenance program be developed for the proper maintenance of the fence system, gates, gate operators and related access controls.
Material specifications for chain link fence are listed in the following:
- ASTM (American Society of Testing Materials) Volume 01.06
- Federal Specification RR-F-191 K/GEN, 14 May 1990
- ASTM F 1553, "The Standard Guide for Specifying Chain Link Fence" will provide he appropriate information to develop a specification document.
The framework for a chain link fence consists of the line posts, end posts, corner posts, gateposts, and if required top, mid, bottom or brace rail. The Federal Specification and The CLFMI "Wind Load Guide for the Selection of Line Post Spacing and Size" provides recommended post sizes for the various fence heights. However the latter document also provides choices of line post types, sizes and spacings to accommodate selected fence heights and fabric sizes for wind loads at various geographical project locations. The CLFMI Product Manual, ASTM F1043 & ASTM F1083, as well as the Federal Specification, list the material specifications for the framework.
Chain Link Fabric:
The material specification for chain link fabric is thoroughly spelled out in the CLFMI Product Manual, ASTM and the Federal Specifications. The choice of chain link fabric will govern the desired security level, and the various fabric-coating choices will govern the corrosion resistance. Light gauge residential chain link fabric will not be considered in this document. Provided are only those chain link fabrics that offer a level of security, thus the gauge of wire and mesh size has been narrowed down to the following:
11 gauge (0.120" diameter)
having minimum break strength of 850 lbf
9 gauge (0.148" diameter)
having minimum break strength of 1290 lbf
6 gauge (0.192"diameter)
having minimum break strength of 2170 lbf
Mesh sizes to consider (mesh size is the minimum clear distance between the wires forming the parallel sides of the mesh) are 2"mesh, 1" mesh and 3/8" mesh. Consider the following regarding mesh size:
- The smaller the mesh size the more difficult to climb or cut.
- The heavier the gauge wire the more difficult to cut.
The various mesh sizes available in the three previously discussed gauges are listed in the order of their penetration resistance/security:
| A. Extremely high security
B. Very high security
C. High security
D. Greater security
E. Normal Industrial security
3/8"mesh 11 gauge
1" mesh 9 gauge
1" mesh 11 gauge
2" mesh 6 gauge
2" mesh 9 gauge