Mastering This lesson, World War I troopers would deploy barbed wire in so-known as concertinas which were comparatively unfastened. Barbed wire concertinas may be prepared while in the trenches and after that deployed in no-male's-land fairly promptly below address of darkness. Barbed wire can be a style of metallic fence https://www.qunkunmetal.com/fencing/concertina-razor-wire.html