1. n. [Drilling]

A steel cable attached to the rig derrick or mast near the work platform for the derrickman. This cable is anchored at surface level (on a vessel or the Earth) away from the mast in a loose catenary profile, and fitted with a handle and hand brake that is stored at the top. The escape line provides a rapid escape path for the derrickman should well conditions or massive mechanical failure warrant. In such a case the derrickman would disconnect his safety belt from the rig, rehook it over the escape line if time permitted, firmly grip the tee-bar handle and ride the trolley down the cable while holding on to the handle with his hands. The escape line is also known as the "Geronimo line."

See: derrick,  derrickman,  mast