RISING/DESCEND STRUCTURE TYPE DERRICK AND RISING/DESCEND METHOD OF THE DERRICK

摘要

An elevation structure type derrick for an offshore structure is disclosed. The elevation structure type derrick for an offshore structure comprises a post body (110) installed in a drill floor (14); a derrick structure (100′) installed in the upper part of the post body (110); a gear box installed in one side of the post body (110) and coupled to a driving motor (121); a relay gear (130) installed in the post body (110) to be rotated so that it can be engaged with the gear box (120); a pinion (140) installed in the post body (110) to be rotated so that it can be engaged with the relay gear (130); a post (150) supporting the bottom of the derrick structure (100′) to elevate the derrick structure (100′), installed in the other side of the post body (110) to be vertically elevated, and having a rack (151) formed on one surface to be engaged with the pinion (140); and a stopper installed in the post body (110) to fix the elevation position of the post (150).