A sheerleg is a floating crane

Crane (machine)

A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...

, but compared to crane vessel

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 catamaran or semi-submersible types as they have increased...

 it is not capable of rotating the crane separate from the ship.

There is a huge variety in sheerlegs when it comes to size and capacity. The smaller cranes start around 50 tons in lifting capacity, with the largest being able to lift over 4000 tons. The bigger sheerlegs usually have their own propulsion system and have a large accommodation facility onboard, while smaller units are a floating pontoon

Pontoon (boat)

A pontoon is a flotation device with buoyancy sufficient to float itself as well as a heavy load. A pontoon boat is a flattish boat that relies on pontoons to float. Pontoons may be used on boats, rafts, barges, docks, floatplanes or seaplanes. Pontoons may support a platform, creating a raft. A...

s that need be towed to their workplace by tugboat

Tugboat

A tugboat is a boat that maneuvers vessels by pushing or towing them. Tugs move vessels that either should not move themselves, such as ships in a crowded harbor or a narrow canal,or those that cannot move by themselves, such as barges, disabled ships, or oil platforms. Tugboats are powerful for...

s.

Common work that sheerlegs are used for are ships salvage

Marine salvage

Marine salvage is the process of rescuing a ship, its cargo, or other property from peril. Salvage encompasses rescue towing, refloating a sunken or grounded vessel, or patching or repairing a ship...

, assistance in shipbuilding

Shipbuilding

Shipbuilding is the construction of ships and 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 before recorded history.Shipbuilding and ship repairs, both...

, loading and unloading large cargo

Stevedore

Stevedore, dockworker, docker, dock labourer, wharfie and longshoreman can have various waterfront-related meanings concerning loading and unloading ships, according to place and country....

 into ships, and bridge building. They have grown considerably larger over the last decades because of growth, mainly because the parts for constructing ships and harbor equipment has grown as well.

Biggest sheerlegs

Biggest sheerlegs
Name	Company	Lifting capacity (in tons)	Country
Svanen	Ballast Nedam	8700 ton	Netherlands
HL 5000		4536 ton	Saint Vincent and the Grenadines
kaisho	IHI	4100 ton	JAPAN
Yoshida No.50		3700 ton	Japan
Musashi	Fukada Salvage	3700 ton	Japan
Rambiz	Scaldis	3300 tons	Belgium
Asian Hercules II	Asian Lift (Smit Smit International Smit Internationale N.V. is a Dutch company operating in the maritime sector. The company was founded in 1842 by Fop Smit as a towage company with only the 140 hp paddle steamer tug 'Kinderdijk'....  & Keppel FELS Keppel Corporation The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others.... )	3200 ton	Singapore
Fuji	Fukada Salvage	3000 ton	Japan
SADAF3000	Deep Offshore Technology	3000 ton	Iran
Taklift 4	Smit Internationale	2200 ton	Netherlands
Suruga	Fukada Salvage	2200 ton	Japan
Kongo	Fukada Salvage	2050 ton	Japan
Matador 3	Bonn & Mees	1800 ton	Netherlands
Asian Hercules	Asian Lift (Smit Smit International Smit Internationale N.V. is a Dutch company operating in the maritime sector. The company was founded in 1842 by Fop Smit as a towage company with only the 140 hp paddle steamer tug 'Kinderdijk'....  & Keppel FELS Keppel Corporation The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others.... )	1600 ton	Singapore
Taklift 6	Asian Lift (Smit Smit International Smit Internationale N.V. is a Dutch company operating in the maritime sector. The company was founded in 1842 by Fop Smit as a towage company with only the 140 hp paddle steamer tug 'Kinderdijk'....  & Keppel FELS Keppel Corporation The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others.... )	1600 ton	Singapore
PW L-1501	Pacific Workboats Pte Ltd	1500 ton	Singapore
Lifter 1	Saipem Saipem Saipem S.p.A. is an Italian oil and gas industry contractor. It is a subsidiary of Italian energy company Eni, which owns approximately 43% of Saipem's shares. Saipem has contracted for designing and constructing several pipelines, including Blue Stream, Greenstream, Nord Stream and South...	1400 ton	Malta
Shin-kenryu	Yorigami Maritime Construction Co	1400 ton	Japan
Shin-hakuho	Yorigami Maritime Construction Co	1300 ton	Japan
Taklift 7	Smit Internationale	1200 ton	Netherlands
Smit Cyclone	Asian Lift (Smit Smit International Smit Internationale N.V. is a Dutch company operating in the maritime sector. The company was founded in 1842 by Fop Smit as a towage company with only the 140 hp paddle steamer tug 'Kinderdijk'....  & Keppel FELS Keppel Corporation The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others.... )	1000 ton	Bahamas
Taklift 1	Smit Internationale	800 ton	Netherlands
PW L-801	Pacific Workboats Pte Ltd	800 ton	Singapore
Izu	Fukada Salvage	700 ton	Japan
Yamato	Fukada Salvage	700 ton	Japan
Koei-go	Fukada Salvage	600 ton	Japan
Uglen	J.J Ugland	600 ton	Norway
Norma	Scaldis	440 ton	Belgium
Asian Helping Hand III	Asian Lift (Smit Smit International Smit Internationale N.V. is a Dutch company operating in the maritime sector. The company was founded in 1842 by Fop Smit as a towage company with only the 140 hp paddle steamer tug 'Kinderdijk'....  & Keppel FELS Keppel Corporation The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others.... )	400 ton	Singapore
GPS Apollo	GPS Marine	400 ton	UK / Netherlands
GPS Atlas	GPS Marine	400 ton	UK / Netherlands
Matador 1	Bonn & Mees	400 ton	Netherlands
Matador 2	Bonn & Mees	400 ton	Netherlands
Smit Typhoon	Asian Lift (Smit Smit International Smit Internationale N.V. is a Dutch company operating in the maritime sector. The company was founded in 1842 by Fop Smit as a towage company with only the 140 hp paddle steamer tug 'Kinderdijk'....  & Keppel FELS Keppel Corporation The Keppel Group of Companies includes Keppel Offshore & Marine, Keppel Integrated Engineering, Keppel Energy, Keppel Telecommunications & Transportation and Keppel Land, among others.... )	400 ton	Bahamas
Consulado de Bilbao	Naviera Murueta	400 ton	España
Amsterdam	Mammoet Mammoet Mammoet is a privately held Dutch company specializing in the hoisting and transporting of heavy objects.- History :Mammoet was founded in 1973, specialised in heavy transport over water and roads. In 2001 it was taken over by Van Seumeren transport. The name Mammoet became the name for the new... Maritime	300 ton	Netherlands
Floating Crane No. 303	Fukada Salvage	300 ton	Japan
Triton	Wagenborg Towage	300 ton	Netherlands / Germany