InterlockingA general term applied to the setting and releasing of Signals and Points to prevent unsafe conditions arising; also the equipment which performs this function.... between two Routes that require one or more PointsItems of permanent way which may be aligned to one of two positions, Normal or Reverse, according to the direction of train movement required. Set in
opposite positions. See also Direct Opposing LockingInterlocking between two Routes in opposite directions for which the lie of all points is the same..