▁with ▁a ▁system ▁of ▁pip es ▁deliver ing ▁exhaust ▁f umes ▁into ▁the ▁gas ▁ch amb ers . ▁For ▁very ▁small ▁trans ports ▁of ▁Jews ▁and ▁Gy ps ies ▁over ▁a ▁short ▁distance , ▁a ▁minim ised ▁version ▁of ▁the ▁gas ▁van ▁technology ▁was ▁also ▁used ▁in ▁Be ł ż ec . ▁The ▁T - 4 ▁SS ▁man ▁and ▁first ▁operator ▁of ▁the ▁gas ▁ch amb ers , ▁Lor enz ▁H ack en hol t , ▁re built ▁an ▁Op el - Bl itz ▁post - office ▁vehicle ▁with ▁the ▁help ▁of ▁a ▁local ▁craft s man ▁into ▁a ▁small ▁gas ▁van . ▁ ▁Con ce al ment ▁of ▁camp ' s ▁purpose ▁Be ł ż ec ▁" processing " ▁zone ▁consisted ▁of ▁two ▁sections ▁surrounded ▁by ▁a ▁high ▁bar bed ▁wire ▁f ence ▁cam ou fl aged ▁with ▁cut ▁fir ▁branches : ▁Camp ▁ 1 , ▁which ▁included ▁the ▁vict ims ' ▁un loading ▁area ▁with ▁two ▁und ress ing ▁bar ra cks ▁further ▁up ; ▁as ▁well ▁as ▁Camp ▁ 2 , ▁which ▁contained ▁the ▁gas ▁ch amb ers ▁and ▁the ▁mass ▁gra ves ▁d ug ▁by ▁the ▁craw ler ▁exc av ator . ▁The ▁two ▁zones ▁were ▁completely ▁screen ed ▁from ▁each ▁other ▁and ▁connected ▁only ▁by ▁a ▁narrow ▁cor rid or ▁called ▁der ▁Sch la uch , ▁or ▁" the ▁T ube ". ▁All ▁arriv ing ▁Jews ▁dis emb ark ed ▁from ▁the ▁trains ▁at ▁a ▁platform ▁in ▁the ▁reception ▁zone . ▁They ▁were ▁met ▁by ▁SS - S