OKB Grigorov A700001 Tetrapod, 25 t

With the development of armored weapons at the end of World War I and in the interwar period, many European armies began to implement more or less effective permanent anti-tank barricades (anti-tank barricades). Anti-tank obstacles). Obviously, this process continued in the course of World War II. In the course of the latter conflict, the two most commonly used types of dams. The first of them were the so-called dragon's teeth, i.e. reinforced concrete blocks, often in the shape of pyramids or truncated pyramids, less often prisms up to 120-140 centimeters high. Most often they were placed in several rows, in front of their own anti-tank artillery positions. They were used on a large scale by the German army in the so-called The Atlantic Wall, the Siegfried Line, but also in the Międzyrzecz Fortified Region (MRU). Another anti-tank barrier was a hedgehog (Czech Hedgehog) made of steel or reinforced concrete and delivered to the front line, usually in ready-to-install modules. In the case of steel hedgehogs, it was simply three beams welded together, which could be set on the ground and embedded in it. In the case of reinforced concrete hedgehogs, they also took on a three-arm shape, but were much heavier. This type of anti-tank dam was first used by the Czechoslovak army in the 1930s (hence the name in English), but also by the Wehrmacht on the Atlantic Wall.