A crane vessel, crane ship or floating crane is a ship with a crane specialized in lifting heavy loads. The largest crane vessels are used for offshore construction. Conventional monohulls are used, but the largest crane vessels are often catamaran or semi-submersible types as they have increased stability. On a sheerleg crane, the crane is fixed and cannot rotate, and the vessel therefore is manoeuvered to place loads. As of 2019, the largest crane vessel in the world is the CNOOC Limited owned Lanjing, having 3 cranes of capacities 7500 tonnes, 4000 tonnes and 1600 tonnes.
