Concertina wire

It is also used in non-military settings, such as when used in prison barriers, detention camps, riot control, or at international borders.

[2] More elaborate and formidable obstructions could be formed with multiple lines of stakes connected with wire running from side-to-side, back-to-front, and diagonally in many directions.

Learning this lesson, World War I soldiers would deploy barbed wire in so-called concertinas that were relatively loose.

Barbed wire concertinas could be prepared in the trenches and then deployed in no-man's-land relatively quickly under cover of darkness.

A platoon of soldiers can deploy a single concertina fence at a rate of about a kilometre (5⁄8 mile) per hour.

Such an obstacle is not very effective by itself (although it will still hinder an enemy advance under the guns of the defenders), and concertinas are normally built up into more elaborate patterns as time permits.

Today, concertina wire is factory made and is available in forms that can be deployed very rapidly from the back of a vehicle or trailer.