A rig used largely in the U.S.A. with a swinging derrick to return it to a position plumbing the hold after it has hoister out a load.
Ukuxhotyiswa kwesikhephe ngemasti kusetyenziswa kubukhulu eU.S.A. ngojulo lwesilenge sokuxhobisa ekubuyiseni kwisithuba sobambo emva koko iye ikhuseleke ngaphandle kumthwalo.