Concertina wire Concertina wire or Dannert Wire is a type of barbed wire or razor wire that is formed in large coils which can be expanded like a concertina . In conjunction with plain barbed wire and steel pickets , it is used to form military wire obstacle s . During World War I soldiers manufactured concertina wire themselves , using ordinary barbed wire . Today , it is factory made . Origins . In World War I , barbed wire obstacles were made by stretching lengths of barbed wire between stakes of wood or iron . At its simplest , such a barrier would resemble a fence as might be used for agricultural purposes . The double apron fence comprised a line of pickets with wires running diagonally down to points on the ground either side of the fence . Horizontal wires were attached to these diagonals . 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 every possible direction . Effective as these obstacles were , their construction took considerable time . Barbed wire obstacles were vulnerable to being pushed about by artillery shells and in World War I this frequently resulted in a mass of randomly entangled wires that could be even more daunting than a carefully constructed obstacle . Learning this lesson , World War I soldiers would deploy barbed wire in so - called concertinas that were relatively loose . Barbed wire concertinas could be pre - prepared in the trenches and then deployed in no - man ' s - land relatively quickly under cover of darkness . Concertina wire packs flat for ease of transport and can then be deployed as an obstacle much more quickly than ordinary barbed wire . A platoon of soldiers can deploy a single concertina fence at a rate of about a kilometer per hour . Such an obstacle is not very effective by itself , 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 . Dannert wire . Oil - tempered barbed wire was developed during World War I ; it was much harder to cut than ordinary barbed wire . During the 1930s , German Horst Dannert developed concertinas of this high - grade steel wire . The result was entirely self - supporting ; it did not require any vertical posts . An individual Dannert wire concertina could be compressed into a compact coil that could be carried by one man and then stretched out along its axis to make a barrier long and each coil could be held in place with just three staples hammered into the ground . Dannert wire was imported into Britain from Germany before World War II . During the invasion crisis of 1940 – 1941 , the demand for Dannert wire was so great that some was produced with low manganese steel wire which was easier to cut . This material was known as " Yellow Dannert " after the identifying yellow paint on the concertina handles . To compensate for the reduced effectiveness of Yellow Dannert , an extra supply of pickets were issued in lieu of screw pickets . Triple concertina wire . A barrier known as a triple concertina wire fence consists of two parallel concertinas joined by twists of wire and topped by a third concertina similarly attached . The result was an extremely effective barrier with many of the desirable properties of a random entanglement . A triple concertina fence could be deployed very quickly : it is possible for a party of five men to deploy of triple concertina fence in just 15 minutes . Optionally , triple concertina fence could be strengthened with uprights , but this increases the construction time significantly . " Constantine " wire . Concertina wire is sometimes mistakenly called " constantine " wire . " Constantine " probably came from a corruption / misunderstanding of " Concertina " and led to confusion with the Roman Emperor Constantine . This in turn has led to some people trying to differentiate between concertina wire and " constantine " wire by assigning the latter term to what is commonly known as razor wire . In contrast to the double - helical construction of concertina wire , as shown being deployed by soldiers in the image , razor wire , or less commonly " constantine wire " , consists of a single wire with projecting teeth periodically along its length .