Patent ID: 7571824

Claim:
A method of converting off-shore installed pedestal crane from a mechanical to a hydraulic operation, said crane having a pedestal secured to an off-shore platform, a turntable attached to said pedestal, a main frame rotatably attached to said turntable, a boom pivotally mounted on said main frame and having cables and hooks suspended therefrom, a winch frame secured to said main frame and having a pair of side members and a operator cab secured to said main frame, said method comprising the steps of: (a) determining a load limit capable of being lifted by said hooks of said crane; (b) ascertaining structural condition of said crane; (c) determining operating performance parameters for a hydraulic system; (d) selecting members of said hydraulically operated system in accordance with said operating performance parameters determined in step (c), said members including a triad of winches, a pair of gearboxes, a pump drive assembly, a reservoir of hydraulic fluid and plurality of control valves; (e) defining configuration and position of mounting members to mount each hydraulically operated winch and gearbox selected in step (d); (f) removing existing mechanically operated and auxiliary members to be replaced; (g) rigidly securing each mounting member defined in step (e) to vertical side members of said winch frame; (h) mounting each of said triad of hydraulically operated winches to a respective mounting member; (i) attaching each cable to a respective winch; (j) mounting each of said pair of hydraulically operated gearboxes to remaining mounting members in operable engagement with said turntable; (k) attaching pump drive assembly to said engine; (l) installing said reservoir of hydraulic fluid and plurality of control valves; (m) interconnecting said hydraulically operated winches attached in step (h), said gearboxes attached in step (j), and said pump drive assembly attached in step (k) with said reservoir of hydraulic fluid and plurality of control valves installed in step (l); (n) testing performance of said hydraulically operated members of said hydraulic system attached in steps (h), (j) and (l) and connected in step (m); and (o) certifying, by a certifying agency, performance of said hydraulic system tested in step (n).