▁directly ▁by ▁the ▁T ung ▁Ch ung ▁Line ▁and ▁the ▁T se ung ▁K wan ▁O ▁Line ▁on ▁Hong ▁Kong ▁Island , ▁but ▁east - west ▁direction al ▁traffic ▁along ▁the ▁existing ▁Island ▁Line ▁would ▁be ▁interrupted ▁and ▁require ▁an ▁inter change . ▁Also , ▁the ▁maximum ▁train ▁frequency ▁between ▁Fort ress ▁Hill ▁and ▁Ch ai ▁W an ▁St ations , ▁which ▁would ▁be ▁served ▁by ▁the ▁T ung ▁Ch ung ▁Line , ▁would ▁have ▁to ▁reduce ▁by ▁ 8 ▁trains ▁per ▁hour ▁because ▁the ▁service ▁frequency ▁of ▁the ▁T ung ▁Ch ung ▁Line ▁is ▁restricted ▁by ▁the ▁capacity ▁of ▁the ▁T sing ▁Ma ▁Bridge . ▁Also , ▁the ▁sign alling ▁system ▁and ▁rolling ▁stock ▁used ▁on ▁both ▁lines ▁are ▁different , ▁so ▁the ▁“ swap ” ▁scheme ▁was ▁not ▁considered ▁in ▁the ▁plan . ▁ ▁" Inter change " ▁scheme ▁Both ▁the ▁existing ▁T ung ▁Ch ung ▁Line ▁and ▁T se ung ▁K wan ▁O ▁Line ▁would ▁be ▁extended ▁along ▁the ▁northern ▁coast ▁of ▁Hong ▁Kong ▁Island . ▁Three ▁stations , ▁namely ▁T amar , ▁Ex hib ition ▁and ▁C ause way ▁Bay ▁North , ▁would ▁be ▁constructed ▁along ▁the ▁extensions , ▁and ▁either ▁T amar ▁or ▁C ause way ▁Bay ▁North ▁Station ▁would ▁be ▁chosen ▁as ▁an ▁inter change ▁between ▁the ▁two ▁lines . ▁ ▁This ▁scheme ▁would ▁preserve ▁the ▁existing ▁Island ▁Line ▁in ▁its ▁current ▁form ▁and ▁would ▁not ▁change ▁the ▁current ▁comm uting ▁pattern ▁between ▁the ▁Central , ▁Western ▁and ▁Eastern ▁District s . ▁However , ▁as ▁the ▁T