A floating sheerleg (also: shearleg) is a floating water vessel with a
crane built on
shear legs
Shear legs, also known as sheers, shears, or sheer legs, are a form of two-legged lifting device. Shear legs may be permanent, formed of a solid A-frame and supports, as commonly seen on land and the floating sheerleg, or temporary, as aboard a ...
. Unlike other types of
crane vessel
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 catam ...
, it is not capable of rotating its crane independently of its hull.
There is a huge variety in sheerleg capacity. The smaller cranes start at around 50 tons in lifting capacity, with the largest being able to lift 10,000 tons. The bigger sheerlegs usually have their own propulsion system and have a large accommodation facility on board, while smaller units are floating
pontoons that need to be towed to their workplace by
tugboat
A tugboat or tug is a marine vessel that manoeuvres other vessels by pushing or pulling them, with direct contact or a tow line. These boats typically tug ships in circumstances where they cannot or should not move under their own power, su ...
s.
Sheerlegs are commonly used for
salvaging ships, assistance in
shipbuilding
Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to befor ...
,
loading and unloading large cargo into ships, and bridge building. They have grown considerably larger over the last decades due to a marked increase in vessel, cargo, and component size (of ships, offshore oil rigs, and other large fabrications), resulting in heavier lifts both during construction and in salvage operations.
List of floating sheerlegs by lifting capacity
;Notes
References
{{Reflist
Cranes (machines)
Crane vessels
Floating cranes
Individual cranes (machines)