▁of ▁co il ▁primary ▁susp ension , ▁and ▁flex ico il ▁secondary ▁susp ension ▁with ▁anti - h un ting ▁and ▁anti - rock ing ▁d amp ers . ▁T ract ive ▁forces ▁from ▁bog ie ▁to ▁locomot ive ▁were ▁transferred ▁via ▁tra ction ▁ro ds ▁connected ▁to ▁a ▁low ▁lying ▁connection ▁at ▁the ▁bog ie ▁pivot ▁centre . ▁Mechan ical ▁bra king ▁was ▁by ▁wheel ▁mounted ▁disc ▁bra kes . ▁Electric ▁bra king ▁is ▁either ▁up ▁to ▁ 4 . 5 MW ▁r he ost atic ▁bra king ▁via ▁roof ▁mounted ▁resist ors , ▁or ▁up ▁to ▁ 7 . 2 MW ▁reg ener ative ▁bra king . ▁ ▁The ▁locomot ives ▁are ▁designed ▁to ▁operate ▁in ▁winter ▁conditions ▁down ▁to ▁, ▁and ▁incorpor ates ▁under frame ▁snow pl ows . ▁ ▁The ▁locomot ive ▁design ▁was ▁proposed ▁as ▁the ▁base ▁for ▁a ▁number ▁of ▁design ▁variants : ▁ ▁a ▁single ▁unit ▁dual ▁voltage ▁fre ight ▁variant ▁E 2 0 , ▁and ▁dual ▁unit ▁dual ▁voltage ▁fre ight ▁variant ▁ 2 ES 2 0 , ▁as ▁well ▁as ▁single ▁voltage ▁DC ▁and ▁AC ▁machines . ▁Add itional ▁variants ▁with ▁a ▁design ▁derived ▁from ▁the ▁EP 2 0 ▁are ▁fre ight ▁and ▁passenger ▁ 4 ▁ax le ▁Bo ' Bo ' ▁based ▁machines . ▁ ▁History ▁By ▁ 2 0 0 7 ▁Russian ▁Rail ways ▁had ▁identified ▁a ▁need ▁for ▁ 2 3 0 ▁units ▁of ▁a ▁series ▁of ▁new ▁electric ▁locomot ive , ▁designated ▁EP 2 0 ; ▁at ▁that ▁time ▁Trans