▁used ▁in ▁support ▁of ▁the ▁inf antry . ▁Through ▁the ▁ 1 9 2 0 s ▁a ▁number ▁of ▁the or ists ▁out lined ▁an ▁independent ▁role ▁for ▁the ▁tank ▁that ▁required ▁it ▁to ▁move ▁at ▁high ▁speed ▁into ▁the ▁rear ▁areas , ▁a ▁modern ▁version ▁of ▁the ▁caval ry . ▁The ▁British ▁referred ▁to ▁these ▁designs ▁as ▁" c ru iser ▁t anks ", ▁but ▁similar ▁high - speed ▁designs ▁were ▁developed ▁under ▁a ▁variety ▁of ▁names . ▁As ▁the ▁Def ense ▁Act ▁limited ▁tank ▁development ▁to ▁the ▁inf antry , ▁the ▁United ▁States ▁Caval ry ▁began ▁tank ▁development ▁under ▁the ▁name ▁" com bat ▁car ". ▁In ▁keeping ▁with ▁the ▁high - speed ▁role , ▁the ▁new ▁T 5 ▁combat ▁car ▁introduced ▁the ▁new ▁vertical ▁vol ute ▁spring ▁susp ension ▁( V V SS ) ▁system , ▁which ▁proved ▁clearly ▁superior ▁to ▁the ▁V ick ers ▁leaf ▁spring ▁system . ▁ ▁This ▁led ▁to ▁a ▁second ▁prototype ▁of ▁the ▁T 2 , ▁the ▁T 2 E 1 , ▁in ▁April ▁ 1 9 3 4 , ▁adopt ing ▁the ▁V V SS ▁from ▁the ▁T 5 . ▁The ▁T 2 E 1 ▁was ▁armed ▁with ▁one ▁. 3 0 ▁cal ▁( 7 . 6 2   mm ) ▁and ▁one ▁. 5 0 ▁in ch ▁( 1 2 . 7   mm ) ▁Brow ning ▁machine ▁gun ▁mounted ▁in ▁a ▁fixed ▁tur ret ; ▁another ▁. 3 0 ▁cal ▁Brow ning ▁was ▁mounted ▁on ▁the ▁h ull ▁front . ▁The ▁T