These barbed wire fences are made from continuous, no-join high tensile wires in a reverse twist pattern. This design provides maximum strength and stability with the ability to unravel when under abnormal loads so it won't break or cause injury if someone trips on one of these strands while trying cross over its length during an eventful night time escape.
The closer spacing also means more points where they can be attached which helps keep stock secure - especially since you want them anchoring themselves as securely possible given what might happen next.