▁the ▁bow ▁into ▁anything ▁of ▁a ▁sea , ▁resulting ▁in ▁a ▁very ▁wet ▁con ning ▁position . ▁ ▁They ▁generally ▁disp la ced ▁around ▁ 3 5 0 ▁tons , ▁one ▁third ▁more ▁than ▁the ▁preceding ▁, ▁giving ▁an ▁increase ▁in ▁speed ▁of ▁ ▁over ▁the ▁" 2 7 ▁kn ot ters ". ▁L ength ▁was ▁around ▁. ▁All ▁were ▁power ed ▁by ▁triple ▁expansion ▁steam ▁engines ▁and ▁had ▁coal - f ired ▁water - t ube ▁bo ilers . ▁However , ▁Alb ac ore , ▁Arab , ▁Bon etta , ▁Cob ra ▁and ▁Express ▁were ▁builder ' s ▁spe ci als , ▁and ▁had ▁steam ▁tur b ines ▁fitted ▁in ▁addition ▁to , ▁or ▁in ▁lieu ▁of , ▁the ▁reci proc ating ▁engines , ▁giving ▁ ▁to ▁ ▁for ▁. ▁Arm ament ▁was ▁one ▁Q F ▁ 1 2 - p ound er ▁gun ▁on ▁a ▁raised ▁platform ▁at ▁the ▁rear ▁of ▁the ▁forec ast le , ▁five ▁Q F ▁ 6 - p ound er ▁guns ▁( two ▁s ided ▁ab re ast ▁the ▁con ning ▁tower , ▁two ▁s ided ▁between ▁the ▁fun n els ▁and ▁one ▁on ▁the ▁quarter deck ) ▁and ▁ 2 ▁single ▁tor ped o ▁tub es ▁for ▁ 1 8 - inch ▁( 4 5 0 ▁mm ) ▁tor ped o es . ▁ ▁The ▁last ▁two ▁Pal mers ▁boats , ▁built ▁in ▁ 1 9 0 8 , ▁were ▁rep lac ements ▁for ▁the ▁ ▁G ala ▁and ▁the ▁C - class ▁T iger