Siegfried Brosow joing the SS/VT in November 1937 and was assigned to the Pionier Rekrutenabteilung led by Rudolf Enseling. He attened Junkerschule Braunschweig from 1939-40. After his schooling he was assigned to the Brückenkolonne which he commanded until July 1941. While with 2.Kompanie he was wounded in February 1942. After recovering he was a instructor at SS-Junkerschule Bad Tölz and then moved to the SS-Pionierschule in the fall of 1942. He returned to his battalion in January 1943 as 1.Kompanie Chef and held that command until he became the Ic on the divisional staff in October 1943. During the rebuilding of Das Reich in 1944 he became the temporary Pionier Bataillonskommandeur and assumed full command when Enseling transferred to the Panzer Regiment during the Normandy Coampaign. He led the Bataillon until February 1945 when he was reassigned to the SS-Pionierschule as a Lehrgruppenkommandeur and ended the war at this post.