This train does not halt at ERN/Ernakulam North. Island Exp halts at ERN at moves towards Kottayam. Both line meet at Kayamkulam.Jn. This train overtakes Island exp before ERN and halts at ERS. Island will halt at ERN. So no problem this train can easily be passed as it directly have halt at ERS and later on this train is getting ahead by an hour at meeting point, i.e Kayamkulam.Jn.