Abstract: A fencing component is made from substantially co-planar loops of barbed tape which overlie each other and which are progressively spaced apart in a first direction. The sizes of the loops are chosen so that the overlying loops form apertures of desired sizes.

Abstract: Security apparatus which has an outer concertina coil of barbed tape with an inner coiled electrical conductor, which may also be made from a concertina coil of barbed tape, positioned within the outer concertina coil and supported therefrom by means of insulators which prevent the conductor from coming in to electrical contact with the outer concertina coil.

Abstract: A barrier which is extensibly deployed from a vehicle and which includes at least three coils of barbed tape supported and spaced from one another with an upper coil located above two lower coils. The coils are spaced parallel from one another, and are supported, by transverse rods located along the respective lengths of the coils. Each coil is a plurality of short coils which are interconnected in axial alignment in head-to-tail relation, with adjacent short coils having oppositely directed senses of rotation to counterbalance any net rotational forces produced by each short coil.