▁difficult ▁to ▁ful fill , ▁requiring ▁that ▁min ers ▁put ▁in ▁ 1 6 - ▁to ▁ 1 8 - hour ▁work days . ▁Fail ure ▁to ▁ful fill ▁quot as ▁could ▁result ▁in ▁tre ason ▁charges . ▁Working ▁conditions ▁were ▁poor , ▁even ▁ha z ard ous . ▁Due ▁to ▁the ▁allocation ▁of ▁resources ▁for ▁the ▁industry ▁along ▁with ▁decre asing ▁product ivity ▁since ▁collect iv ization , ▁a ▁fam ine ▁occurred . ▁In ▁the ▁construction ▁of ▁the ▁industrial ▁complex es , ▁in m ates ▁of ▁Gul ag ▁cam ps ▁were ▁used ▁as ▁exp end able ▁resources . ▁But ▁conditions ▁improved ▁rapidly ▁during ▁the ▁second ▁plan . ▁Through out ▁the ▁ 1 9 3 0 s , ▁industrial ization ▁was ▁combined ▁with ▁a ▁rapid ▁expansion ▁of ▁technical ▁and ▁engineering ▁education ▁as ▁well ▁as ▁increasing ▁emphas is ▁on ▁m un itions . ▁ ▁From ▁ 1 9 2 1 ▁until ▁ 1 9 5 4 , ▁the ▁police ▁state ▁operated ▁at ▁high ▁intensity , ▁ ▁seeking ▁out ▁anyone ▁accused ▁of ▁sab ot aging ▁the ▁system . ▁The ▁estimated ▁numbers ▁vary ▁greatly . ▁Perhaps , ▁ 3 . 7 ▁million ▁people ▁were ▁sent enced ▁for ▁alleg ed ▁counter - re volution ary ▁cr imes , ▁including ▁ 6 0 0 , 0 0 0 ▁sent enced ▁to ▁death , ▁ 2 . 4 ▁million ▁sent enced ▁to ▁labor ▁cam ps , ▁and ▁ 7 0 0 , 0 0 0 ▁sent enced ▁to ▁exp atri ation . ▁St alin ist ▁repr ession ▁reached ▁its