▁They ▁had ▁a ▁beam ▁of ▁ ▁and ▁a ▁deep ▁dra ug ht ▁of ▁ ▁forward ▁and ▁ ▁a ft . ▁The ▁class ▁was ▁over ▁ ▁longer ▁overall ▁than ▁the ▁Dev ons h ires ▁and ▁disp la ced ▁over ▁ ▁more . ▁ ▁The ▁ships ' ▁complement ▁was ▁ 7 6 9 ▁officers ▁and ▁en list ed ▁men . ▁They ▁rolled ▁quickly ▁with ▁a ▁met acent ric ▁height ▁of ▁ ▁at ▁deep ▁load ▁and ▁their ▁six - inch ▁guns ▁were ▁as ▁wet ▁as ▁predicted . ▁ ▁The ▁cru is ers ▁were ▁power ed ▁by ▁two ▁ 4 - cy l inder ▁triple - exp ansion ▁steam ▁engines , ▁each ▁driving ▁one ▁sh aft , ▁which ▁produced ▁a ▁total ▁of ▁ ▁and ▁gave ▁a ▁maximum ▁speed ▁of ▁. ▁The ▁engines ▁were ▁power ed ▁by ▁ 2 0 ▁Bab cock ▁& ▁Wil co x ▁water - t ube ▁bo ilers ▁and ▁six ▁cyl ind rical ▁bo ilers . ▁The ▁ships ▁carried ▁a ▁maximum ▁of ▁ ▁of ▁coal ▁and ▁an ▁additional ▁ ▁of ▁fuel ▁oil ▁that ▁was ▁sp rayed ▁on ▁the ▁coal ▁to ▁increase ▁its ▁burn ▁rate . ▁At ▁full ▁capacity , ▁they ▁could ▁steam ▁for ▁ ▁at ▁a ▁speed ▁of ▁. ▁ ▁Arm ament ▁The ▁Duke ▁of ▁Ed in burg hs ▁main ▁arm ament ▁consisted ▁of ▁six ▁ 4 5 - cal ib re ▁B L ▁ 9 . 2 - inch ▁M k ▁X ▁guns ▁in ▁single - gun ▁tur rets , ▁a ▁much ▁more ▁powerful ▁gun ▁than ▁used ▁in ▁the ▁Dev ons h ires