During World War I the company built one single U-boat for the Kaiserliche Marine, the U-157, which under command of the famous Max Valentiner undertook the longest cruise in the war from November 27, 1917 to April 15, 1918, a total of 139 days. During World War II the company built 24 VIIC U-boats for the Kriegsmarine. The company used slave labour of the Neuengamme concentration camp with its own subcamp.[1]