Winkeltürme (air raid shelters)

The towers in this placemarker are called Winkelturm (winkel-tower) and they are named by their designer Leo Winkel (* 15. September 1885 in Köln; † März 1981 in Duisburg). The Winkelturm is a bunker and was patented in 1934, in 1936 the first tower was constructed. Altogether there were nearly 200 Winkeltürme of 5 different types built. The towers were intended mainly as protection for factory workers and railroad personnel, and they appeared most often in areas of heavy industry and rail centers. The first towers were testet 1935 at Luftwaffen-Erprobungsstelle Rechlin. For the dive bomber pilots (Stuka) it was not easy to hit the towers with their bombs, so they decided to place the bombs direct on the top of the tower, and ignite it electrically. After this tests the nazis decleared the tower as direct hit safe against high-explosives bomb, although some goats, which were during the attempts in the towers, were afterwards deaf. The diameter of one Winkelturm is between 8,4m und 10,0m, the hight is between 20,0m and 25,0m with a minimum wall thickness for reinforced concrete of 0,8m or concrete of 1,5m. The biggest tower could gather more than 500 people, the smaller ones 164. There was only one tower that was hit by a bomb. The Winkelturm on the Focke-Wulf-site in Bremen got a direct hit in oktober 1944, five people died.



sources:
http://de.wikipedia.org/wiki/Leo_Winkel
http://bbs.keyhole.com/ubb/ubbthreads.php?ubb=showflat&Number=714412
http://www.thirdreichruins.com/misc_sites3.htm
http://www.luftschutz-bunker.de/content/index.php?option=com_content&task=view&id=158&Itemid=52