Mittelwerk GmbH also headed sites for V-2 rocket development and testing at Schlier (Project Zement) and Lehesten. Beginning in May 1944, Georg Rickhey was the Mittelwerk general manager, Albin Sawatzki was the Mittelwerk technical director over both Arthur Rudolph's Technical Division (with deputy Karl Seidenstuecker) and Hans Lindenberg's 50 engineers of the quality control group located at Ilfeld. Other Mittelwerk/Ilfield engineers included Magnus von Braun in turbopump production, Guenther Haukohl who supervised V-2 production after helping design the assembly line, Eric Ball (assembly line), Hans Fridrich, Hans Palaoro and Rudolph Schlidt. The facility had a communications staff under Captain Dr Kühle, an Administrative Division run by Börner under Mittelwerk board member Otto Karl Bersch, and a Prisoner Labor Supply office ("Brozsat"). Hannelore Bannasch was Sawatzki's secretary.