Only ten days after the raid on Peenemünde, on 28 August 1943, the first 107 KZ inmates from Buchenwald arrived with their SS guards at the Kohnstein. The official name of the new subcamp of Buchenwald was "Arbeitslager Dora". Another 1,223 Buchenwald prisoners followed on 2 September and workers from Peenemünde came in mid-October. Over the next months, many more prisoners were brought to the area in almost daily transports from Buchenwald. By late September, the number of workers had risen to over 3,000, by late October to 6,800 and by Christmas 1943 to more than 10,500. Since there were initially no huts, the prisoners were housed inside the tunnels – in specially designated "Schlafstollen" with four levels of beds stacked over each other.