Floating Crane

A floating crane is a heavy-lift crane mounted on a barge or ship hull, used to lift loads too heavy for shore cranes: bridge sections, offshore jackets and topsides, salvage wrecks, and harbor cargo. Capacity ranges from a few hundred tonnes on a harbor unit to several thousand tonnes on an offshore sheerleg or semi-submersible crane vessel; the largest revolving cranes exceed 5,000 tonnes. A fixed sheerleg crane cannot slew and lifts only over the bow, while a revolving crane works through 360 degrees. Stability under load is the governing design problem, so the hull is wide and heavily ballasted, and offshore units add dynamic positioning to hold station during the lift.