▁ship ▁was ▁prop elled ▁by ▁two ▁four - cy l inder ▁vertical ▁comp ound ▁steam ▁engines , ▁r ated ▁at ▁, ▁fed ▁by ▁steam ▁from ▁four ▁cyl ind rical ▁bo ilers . ▁This ▁gave ▁a ▁speed ▁of ▁. ▁The ▁ship ▁had ▁a ▁single ▁m ast ▁and ▁fun nel . ▁The ▁m ast ▁differ ed ▁slightly ▁from ▁the ▁one ▁in ▁its ▁sister ▁Indep endencia . ▁ ▁As ▁designed , ▁its ▁main ▁battery ▁had ▁two ▁ 2 4 0 mm ▁Kru pp ▁guns ▁( one ▁at ▁the ▁bow ▁and ▁the ▁other ▁at ▁the ▁stern ) ▁on ▁V avas se ur ▁mount ings ▁protected ▁with ▁arm oured ▁shield s , ▁and ▁two ▁quick - f iring ▁ 1 2 0 mm ▁El sw ick ▁guns ▁on ▁each ▁side . ▁The ▁secondary ▁battery ▁had ▁four ▁ 4 7   mm ▁quick - f iring ▁Nord enf elt / Hot chk iss ▁guns , ▁and ▁two ▁ 2 5 mm ▁Nord enf elt ▁guns . ▁ ▁History ▁▁ ▁In ▁July ▁ 1 8 8 9 , ▁the ▁Argent ine ▁Naval ▁Commission ▁in ▁London ▁signed ▁a ▁contract ▁with ▁the ▁ship yard ▁C amm ell ▁La ird ▁of ▁Bir ken head ▁ordering ▁the ▁construction ▁of ▁" two ▁tw in - sh aft , ▁ram - equ ipped ▁batt les hips ▁for ▁river ine ▁service " ▁( Span ish : ▁dos ▁ac or az ados ▁de ▁es pol ón ▁de ▁do ble ▁hé lice ▁para ▁serv icio ▁de ▁r íos ) ▁at ▁a ▁unit ▁cost ▁of ▁£ ▁ 1 7 6