The Drill Floor is the heart of any drilling rig and is also known as the pad. This is the area where the drill string begins its trip into the earth. It is traditionally where joints of pipe are assembled, as well as the BHA (bottom hole assembly), drilling bit, and various other tools. This is the primary work location for roughnecks and the driller, and one of the primary work locations for the derrickman. The drill floor is located directly under the derrick.