' s ▁resist ors ; ▁can ▁move ▁only ▁when ▁pressure ▁is ▁greater ▁than ▁ 5 ▁bars , ▁and ▁the ▁IR ▁must ▁be ▁closed . ▁ ▁Horn ▁and ▁ ▁wh ist le ▁( T rom ba ▁and ▁F isch io ). ▁The ▁locomot ives ▁have ▁two ▁horn s ▁and ▁wh ist les , ▁one ▁above ▁each ▁driving ▁cab . ▁The ▁first s ▁are ▁activ ated ▁by ▁a ▁sol en oid ▁val ve ▁and ▁work ▁only ▁when ▁batter ies ▁are ▁inserted ▁and ▁pressure ▁is ▁greater ▁than ▁ 5 ▁bars , ▁while ▁the ▁seconds ▁can ▁reach ▁their ▁maximum ▁fre quence ▁with ▁press ures ▁of ▁about ▁ 4 ▁bars . ▁ ▁Sand ▁throw ers ▁( S ab bi ere ). ▁As ▁the ▁name ▁suggests , ▁they ▁throw ▁sand ▁on ▁the ▁track , ▁in ▁order ▁to ▁increase ▁ad her ence . ▁They ▁are ▁to ▁be ▁manually ▁activ ated ▁by ▁the ▁driver ▁in ▁case ▁of ▁wheel - s lip , ▁and ▁work ▁with ▁pressure ▁of ▁about ▁ 5 ▁bars . ▁ ▁Fl ange ▁oil ers ▁( U ng ib ordo ). ▁During ▁the ▁ 1 9 7 0 s , ▁in ▁order ▁to ▁con serve ▁the ▁wheel ▁fl ange , ▁the ▁locomot ives ▁have ▁received ▁a ▁De L imon ▁system ▁that ▁sp ray s ▁oil ▁via ▁com pressed ▁air ▁on ▁regular ▁select able ▁intervals ▁into ▁the ▁channel ▁between ▁wheel ▁fl ange ▁and ▁wheel ▁surface ▁of ▁the ▁front ▁wheel . ▁ ▁First ▁p ant ograph - raise ▁compress or ▁( Com press ore ▁di ▁primo ▁al z amento ). ▁This