Dragon's teeth (fortification)

Dragon's teeth (Drachenzähne) are square-pyramidal anti-tank obstacles of reinforced concrete first used during the Second World War to impede the movement of tanks and mechanised infantry. The idea was to slow down and channel tanks into killing zones where they could easily be disposed of by anti-tank weapons. They were employed extensively, particularly on the Siegfried Line. Dragon's teeth were used by several armies in the European theatre. The Germans made extensive use of them on the Siegfried Line and the Atlantic Wall. Typically, each tooth was tall. Land mines were often laid between teeth, and further obstacles were constructed along the lines of teeth, such as barbed wire to impede infantry or diagonally-placed steel beams to further hinder tanks. Many were laid in the United Kingdom in 1940–1941, as part of the effort to strengthen the country's defences against a possible German invasion. Behind minefields were the dragon's teeth. They rested on a concrete mat between ten and thirty meters wide, sunk a meter or two into the ground (to prevent any attempt to tunnel underneath them and place explosive charges). On top of the mat were the teeth themselves, truncated pyramids of reinforced concrete about a meter in height in the front row, to two meters high in the back. They were staggered and spaced in such a manner that a tank could not drive through. Interspersed among the teeth were minefields, barbed wire, and pillboxes that were virtually impregnable by the artillery and set in such a way as to give the Germans crossing fire across the entire front. The only way to take those pillboxes was for infantry to get behind them and attack the rear entry. But behind the first row of pillboxes and dragon’s teeth, there was a second, and often a third, and sometimes a fourth. Due to the huge numbers laid and their durable construction, many thousands of dragon's teeth can still be seen today, especially in the remains of the Siegfrieds. File:Dragons Teeth - Fairbourne Beach - geograph.org.uk - 1413179.