The Blechhammer (English: sheet metal hammer) area was the location of Nazi Germany chemical plants, prisoner of war (POW) camps, and forced labor camps (German: Arbeitslager Blechhammer; also Nummernbücher). Labor camp prisoners began arriving as early as June 17, 1942, and in July 1944, 400-500 men were transferred from the Terezin family camp to Blechhammer. The mobile “pocket furnace” (German: Taschenofen) crematorium was at Sławięcice.) and Bau und Arbeits Battalion (BAB, English: Construction Battalion) 21 was a mile from the Blechhammer oil plants and was not far from Katowitz and Breslau. Blechhammer synthetic oil production began April 1[when?] with 4000 prisoners.
^ abJones, Chris (19 September 2004). "Message 1 - blechammer, el tahag and chieti". WW2 People's War - Dad's Journey. BBC.co.uk. Retrieved 2009-04-21. the main one referred to as 'E3' in the Stalag labour system was to be found there, though the others in and around the area include: BAB 20, 21, 40 and 48; and E711, E711A, E769, E793 E794 (these last two were renamed BAB20 and 21)