Blohm + Voss
At Lübeck Zuchthaus, he got to know the lathe operator, Bruno Rieboldt and metalworker, Dagobert Biermann (father of former East German dissident, Wolf Biermann). After their release, Rieboldt and Biermann went to work at the Hamburg warfs for Blohm + Voss. Rieboldt informed Michaelis about armaments work at Blohm + Voss, particularly regarding the construction of airplane motors and warships.