Berm wall

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A Bermenmauer also grave moat wall designated medieval fortress , a smaller wall between moat and berm.

In medieval fortress construction, Berme referred to a flat piece of earth between the city ​​wall , castle wall or fortress wall or a parapet wall and a ditch in front of it. The berm should absorb the pressure of the wall and so relieve the inner often steep slope of the ditch or the area of ​​the inner trench lining wall / escarp wall in order to avoid static collapse of the fortress wall and the inner ditch embankment . When parts of the wall fell due to bombardment with blids or later mortars and cannons , the existence of a berm largely prevented the debris from filling the trench. A berm wall also made it difficult for the material to slide into the trench.

The berm wall and the fortress wall formed a narrow kennel , the berm kennel , in which penetrated enemies were restricted in their freedom of movement and overview and could be fought well from the higher fortress wall.

Strong berm walls were often built with the advent of the first cannons. With these attackers, with about ten times the impact speed of the stone balls compared to the stone projectiles of the old Bliden (slingshots), the foot of the fortress walls. Sufficiently large holes created there caused the upper parts of the wall to collapse. It initially proved to be an effective means of defense to cover the base of the fortress wall with a heavy protective shield in front of the fortress wall. B. a strong berm wall - to protect. With the rapid progress of heavy siege artillery, however, berm walls, as well as classic fortress walls, ultimately lost their protective function against troops who had this type of armament. The same task of catching cannonballs from the base of the wall was assigned a little later to the raised counter- carp walls .

Literature and source

  • Karl Rudolf Müller: The walls of the Free Imperial City of Speyer as a framework for the city's history , publisher: District group Speyer of the Historical Association of the Palatinate, Speyer 1994, Zechnersche Buchdruckerei, p. 203