dear friends is there any rule as to which horn should be sounded first and which one second i.e lhf or shf for diesel loco and leading cab or non leading cab for electric and.wdp3a locos i am asking this because when i gone to bsr station kcvl porbander exp had a crew change over there and while starting the lp first blew the lhf horn then shf again lhf and lhf again any specific reason for this ? the loco @bsr was lhf working