For maximum security effectiveness where appearance may not be a concern, barbed, razor ribbon, or concertina wire as fence treatment or a top guard may be added to the top of the 8-foot chain-link...

For maximum security effectiveness where appearance may not be a concern, barbed, razor ribbon, or concertina wire as fence treatment or a top guard may be added to the top of the 8-foot chain-link fence. The addition of top guard increases a fence’s deterrent value while also serving to delay or slow the actions of the adversary (American Public Transportation Association, 2010).