Gates are the only moveable part of a fence and therefore should be properly constructed with appropriate fittings. Chain link gate specifications are listed in the CLFMI Product Manual, ASTM and the Federal Specification.
Limiting the size of the opening increases vehicular security, it reduces the possibility of one vehicle passing another and the smaller opening reduces the open close cycle time. The cantilever slide gate is the most effective for vehicle security especially one that is electrically operated and tied into an access control system. High-speed cantilever slide gate operators are available for certain applications.
Pedestrian/personnel gates can be constructed using a basic padlock or designed with an electrical or mechanical lock or a keypad/card key system tied into an access control system. Pre-hung pedestrian gates/portals installed independent of the fence line are available to isolate the gate from fence lines containing sensor systems thus reducing possible false alarms.
Some basic design features to consider that enhance security:
- Height - the higher the barrier the more difficult and time consuming to broach.
- Eliminating top rail - the omission of a rail at the top of the fence eliminates a handhold thus making the fence more difficult to climb. A 7-gauge coil spring wire can be installed in place of the top rail.
- Adding barbed wire - the addition of three or six strands at the top of the fence increases the level of difficulty and time to broach. When using the three-strand 45-degree arm it is recommended to angle the arm out from the secured area.
- Bolt or rivet barbed wire arms to post - barbed wire arms are normally held to the post by the top tension wire or top rail. For added security they can be bolted or riveted to the post.
- Adding barbed tape - stainless steel barbed tape added to the top and in some cases the bottom of the fence greatly increases the difficulty and time to broach.
- Adding bottom rail - the addition of a bottom rail that is secured in the center of the two line post using a 3/8" diameter eye hook anchored into a concrete footing basically eliminates the possibility of forcing the mesh up to crawl under the fence. The bottom of the fence with or without bottom rail should be installed no greater than 2" above grade.
- Bury the chain link fabric - Burying the fabric 12" or more will also eliminate the possibility of forcing the mesh up.
- Color chain link fabric - one of the security features of a chain link fence is visibility, allowing one to monitor what is taking place inside or outside of the fence line more efficiently. Color polymer coated chain link fabric enhances visibility, especially at night. Complete polymer coated systems, coated fabric, fittings, framework and gates, not only increases visibility, but also provides greater corrosion resistance, especially for use in areas adjacent to the seacoast.
- Double row of security fencing- it is not uncommon to add and additional line of internal security fencing 10 to 20 feet inside the perimeter fence. In many cases double rows of fencing are used with sensors and detectors, or with a perimeter patrol road in area between the fences.
- Clear zone - In wooded or high grass areas it is advisable to clear and grub a clear zone on either side of the fence to aid surveillance.
- Internal security fencing - many situations require the need of a separate interior fence to add another level of security for a particular building, piece of equipment, or location.
- Peen all bolts - this eliminates the removal of the bolt nut.
- Addition of a sensor system - this adds another level of security to the fence system.
- Addition of lighting - increases visibility as well as raises the level of psychological deterrent.
- Signage - installed along the fence line, signs are important to indicate private secured areas; violators may be subject to arrest, and possibly noting the presence of alarms and monitoring systems.