Wikipedia
The Redl-Zipf V-2 rocket facility ( code name Schlier) in central Austria between Vöcklabruck and Vöcklamarkt was for V-2 rocket motor testing after Raxwerke test equipment had been moved from Friedrichshafen. The facility tested V-2 combustion chambers' compatibility with turbopumps since the rocket did not have a controller for reducing the turbopumping of propellant into the chamber if pressure became too high. The World War II facility used forced labor of the Schlier-Redl-Zipf subcamp of the Mauthausen-Gusen concentration camp and included a liquid oxygen generation plant in a nearby tunnel.1 After an August 1944 2 explosion at the liquid oxygen plant stopped Schlier production, the third V-2 liquid oxygen plant (5000 tons/month) was built at a slate quarry at Lehesten near the Mittelwerk (turbopump/chamber compatibility testing for Mittelwerk production was also performed at the Lehesten facility). Karl Heimberg, who had worked at Peenemünde Test Stand 7, was transferred to "Vorwerk Sued" at Redl-Zipf and then, for the period from late 1944-early April 1945, to Lehesten (he later returned to Peenemünde with Walter Riedel III to burn design office files and participated in the post-war Operation Backfire.)3
The Operation Bernhard forced labor team at Sachsenhausen concentration camp for producing counterfeit British money was transferred to the Schlier-Redl-Zipf subcamp until the beginning of May 1945, when the team of prisoners was ordered to transfer to the Ebensee concentration camp. A 1985 documentary was produced about the forced labor, and the 1992 conference for Braunau Contemporary History Days commemorated the "Unwanted Heritage" of forced labor at the region's concentration camps.