Several allied reconnaissance missions flown over northern Austria between September 1944 and April 1945 covered important facilities around Linz and Vienna (Wien). Among the facilities imaged were several subcamps of the Mauthausen Concentration Camp. Mauthausen itself was not covered. The subcamps that were imaged included a major facility, Linz III, as well as others at Wien-Schwechat Wien-Florisdorf, Hirtenberg, Steyr and Melk --an unusually large number compared to other major concentration camp systems. A website, The Subcamps - History- KZ-Gedenkstätte Mauthausen, assisted in identifying the subcamps revealing observable differences in layout and security.
The Florisdorf camp, 20 km northwest of Wien-Schwechat (Graphic 3) was established in July 1944 in attempt to disperse production from the Heinkelwerke after that facility came under attack. Prisoners from Schwechat were moved to in Florisdorf where some also worked for another firm, the Akkumulatoren Fabrik AG (AFA Works) which produced submarine batteries. The prisoners lived in a barracks built on a sports field and another near AFA Works. The graphic shows the location of the camp, but it is not clear if it was located in the well-defined barracks/labor camp or two other areas nearby.
A camp at Hirtenberg, 35 km southeast of Vienna, supported a munitions factory, the Otto Eberhardt Patronenfabrik. The first of about 400 female prisoners arrived from Auschwitz on 28 September. The camp occupied part of an existing labor camp and imagery from 4 September 1944 shows that a section of an existing labor camp had recently been fenced-off.
Three Mauthausen subcamps were located at Linz. The largest of these was Linz III, which was set up in May 1944 in a former forced labor camp (Graphic 1). Of all the subcamps Linz III was closest in appearance to a concentration camp. About 6,800 prisoners worked at a major iron and steel works, the Reichswerke ‘Hermann Göring. A smaller camp, Linz I, operated nearby from January 1943.
A camp was established at Steyr in March 1942 (Graphic 5). Up to 3000 prisoners worked at the Steyr-Daimler-Puch AG and Flugmoterenwerke Ostmark. which produced aircraft engines. The camp, adjacent to the aircraft plant was one of two Mauthausen subcamps to have guard towers (two -- Linz III had 14). A barracks and a labor camp were located nearby.
WW2 Aerial Reconnaissance Studies
A subcamp at Wien-Schwechat Airfield supported the Heinkelwerke aircraft assembly plant (Graphic 2). About 2000 prisoners from Mauthausen were transferred Schwechat in late 1943; most lived in a nearby barrack, but some lived in one of the ircraft production halls. Several labor camps were located in the area, so the exact location of the subcamp was unclear. It could have been located in a separately secured area or in an adjacent much larger and better defined labor camp.
In April 1944, a Mauthausen subcamp was set up in an old military installation at Melk, 80 km east of Linz. The camp, which came to hold 14.000 prisoners, supported the digging of tunnels in which to relocate the Daimler-Puch AG and the Flugmoterenwerke Ostmark.