Abstract: A method of converting off-shore installed pedestal crane from a mechanical to a hydraulic operation includes the steps of determining a load limit capable of being lifted by the hooks of the existing crane, ascertaining structural condition of the existing crane, determining operating performance parameters for and selecting various members of a hydraulic system, defining configuration and position of mounting members to mount each selected hydraulically operated member, removing existing mechanically operated components, rigidly securing the mounting members to the existing winch frame, affixing hydraulically operated members to respective mounting member and interconnecting them therebetween with hoses, and testing and certifying performance of the hydraulically operated system.