1. n. [Drilling]

The work shift of a drilling crew that commences at about the sunrise hour. Drilling operations usually take place around the clock because of the cost to rent a rig. As a result, there are usually two separate crews working twelve-hour tours to keep the operation going. Some companies prefer three eight-hour tours: the daylight tour starts at daylight or 8 AM; the graveyard tour is the overnight shift or the shift that begins at midnight. (Pronounced "tower" in many areas.)

Synonyms: morning tour,  tour

See: drilling crew