. ▁ ▁The ▁main ▁charge ▁of ▁the ▁mine ▁used ▁T NT ▁as ▁its ▁explos ive ; ▁the ▁prop elling ▁charge ▁was ▁black ▁pow der . ▁The ▁standard ▁pressure ▁sensor ▁used ▁a ▁per cussion ▁cap ▁to ▁ign ite ▁it . ▁ ▁The ▁main ▁f use ▁was ▁designed ▁to ▁delay ▁the ▁firing ▁of ▁the ▁prop elling ▁charge ▁for ▁approximately ▁four ▁seconds ▁after ▁the ▁mine ▁was ▁triggered . ▁The ▁explos ion ▁of ▁the ▁prop elling ▁charge ▁sent ▁the ▁mine ▁up wards ▁into ▁the ▁air ▁and ▁activ ated ▁three ▁short - delay ▁pel lets ▁between ▁the ▁prop ell ant ▁charge ▁and ▁the ▁three ▁det on ators . ▁These ▁short - delay ▁pel lets ▁delayed ▁the ▁mine ' s ▁det on ation ▁long ▁enough ▁for ▁it ▁to ▁reach ▁an ▁appropriate ▁height ▁before ▁expl oding . ▁ ▁The ▁standard ▁pressure ▁sensor ▁was ▁designed ▁to ▁activ ate ▁if ▁de pressed ▁by ▁a ▁weight ▁of ▁roughly ▁ ▁or ▁greater . ▁This ▁ens ured ▁the ▁mine ▁was ▁not ▁det on ated ▁by ▁wild life ▁or ▁natural ▁impact ▁of ▁blow ing ▁leaves , ▁branches , ▁or ▁other ▁normally ▁occurr ing ▁phen omena . ▁ ▁Us age ▁ ▁The ▁S - mine ▁was ▁normally ▁triggered ▁by ▁a ▁three - pr ong ed ▁pressure ▁f use . ▁It ▁could ▁also ▁be ▁modified ▁to ▁be ▁triggered ▁by ▁a ▁trip wire . ▁A ▁special ▁trip wire ▁adapter ▁was ▁provided ▁by ▁the ▁German ▁army . ▁The ▁steel ▁t ube ▁that ▁held ▁the ▁f use ▁was ▁thread ed ▁to ▁accept ▁any ▁standard ▁German ▁ign ition ▁or ▁trigger , ▁allowing