Security fences of various types are known in the patent literature and available on the market. These include taut-wire fence systems which employ tensionsed wires mounted onto motion sensors, whereby an attempt to cut or spread apart the wires results in an alarm indication of the approximate location of the attempted intrusion.
There are also known a variety of security barriers which employ a fiber optics sensing apparatus. U.K. published patent application No. 2,098,770 describes a security barrier structure comprising a lattice of hollow tubular members through which fiber optic cable is threaded. An attempt to break through the barrier breaks or distorts the fiber by overtensioning same, thus causing a sensible attenuation of the an optical signal transmitted through the cable.
U.K. published patent application Nos. 2,038,060; 2,046,971; and 2,062,321 and U.S. Pat. Nos. 4,292,628 and 4,399,430 all show security applications, wherein an alarm indication is provided by breakage of an optical fiber. U.K. published patent application No. 2,077,471 shows a security application wherein a pressure sensitive fiber optic composite cable is provided.