deadline n: the drilling line from the crown block sheave to the anchor, so called because it does not move. Compare fast line.
deadline anchor n: see deadline tie-down anchor.
deadline sheave n: the sheave on the crown block over which the deadline is reeved.
deadline tie-down anchor n: a device to which the deadline is attached, securely fastened to the mast or derrick substructure. Also called a deadline anchor.