A crane vessel, crane ship or floating crane is a

ship A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...

with a crane specialized in lifting heavy loads. The largest crane vessels are used for offshore construction. Conventional

monohull right A monohull is a type of boat having only one hull, unlike multihulled boats which can have two or more individual hulls connected to one another. Fundamental concept Among the earliest hulls were simple logs, but these were generally unsta ...

s are used, but the largest crane vessels are often

catamaran A Formula 16 beachable catamaran Powered catamaran passenger ferry at Salem, Massachusetts, United States A catamaran () (informally, a "cat") is a multi-hulled watercraft featuring two parallel hulls of equal size. It is a geometry-sta ...

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.

History

In medieval Europe, crane vessels which could be flexibly deployed in the whole port basin were introduced as early as the 14th century. During the

age of sail The Age of Sail is a period that lasted at the latest from the mid-16th (or mid- 15th) to the mid-19th centuries, in which the dominance of sailing ships in global trade and warfare culminated, particularly marked by the introduction of nava ...

, the sheer hulk was used extensively as a floating crane for tasks that required heavy lift. At the time, the heaviest single components of ships were the main masts, and sheer hulks were essential for removing and replacing them, but they were also used for other purposes. Some crane vessels had

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

s for propulsion, others needed to be towed with a

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 ...

. In 1920, the 1898-built

battleship A battleship is a large armour, armored warship with a main artillery battery, battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries. The term ''battleship'' came into use in the late 1 ...

was converted to a crane ship when a crane with a capacity of 250 tons was installed. Later it was renamed ''Crane Ship No. 1''. It was used, amongst other things, to place guns and other heavy items on other battleships under construction. Another remarkable feat was the raising of the

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

in 1939. In 1942, the crane ships a.k.a. "Heavy Lift Ships" SS ''Empire Elgar'' (PQ16), SS ''Empire Bard'' (PQ15), and SS ''Empire Purcell'' (PQ16) were sent to the Russian Arctic ports of

Archangelsk Arkhangelsk (, ; rus, Арха́нгельск, p=ɐrˈxanɡʲɪlʲsk), also known in English as Archangel and Archangelsk, is a city and the administrative center of Arkhangelsk Oblast, Russia. It lies on both banks of the Northern Dvina near ...

, Murmansk and

Molotovsk Severodvinsk ( rus, Северодвинск, p=sʲɪvʲɪrɐdˈvʲinsk) is a city in the north of Arkhangelsk Oblast, Russia, located in the delta of the Northern Dvina, west of Arkhangelsk, the administrative center of the oblast. As of the ...

(since renamed Sererodvinsk). Their role was to enable the unloading of the Arctic convoys where port installations were either destroyed by German

bomber A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped from an air ...

s or were non existent (as at Bakaritsa quay Archangel). In 1949,

J. Ray McDermott McDermott International, Ltd is a global provider of engineering and construction solutions to the energy industry. Operating in over 54 countries, McDermott has more than 40,000 employees, as well as a diversified fleet of specialty marine co ...

had ''Derrick Barge Four'' built, a barge that was outfitted with a revolving crane capable of lifting 150 tons. The arrival of this type of vessel changed the direction of the offshore construction industry. Instead of constructing

oil platform An oil platform (or oil rig, offshore platform, oil production platform, and similar terms) is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platfor ...

s in parts, jackets and decks could be built onshore as modules. For use in the shallow part of the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

, the cradle of the offshore industry, these barges sufficed. In 1963, Heerema converted a Norwegian tanker, ''Sunnaas'', into a crane vessel with a capacity of 300 tons, the first one in the offshore industry that was ship-shaped. It was renamed ''Global Adventurer''. This type of crane vessel was better adapted to the harsh environment of the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian ...

Semi-submersible giants

In 1978, Heerema had two semi-submersible crane vessels built, and , each with one 2,000

ton Ton is the name of any one of several units of measure. It has a long history and has acquired several meanings and uses. Mainly it describes units of weight. Confusion can arise because ''ton'' can mean * the long ton, which is 2,240 pounds ...

and one 3,000 ton crane. Later both were upgraded to a higher capacity. This type of crane vessel was much less sensitive to sea swell, so that it was possible to operate on the North Sea during the winter months. The high stability also allowed for heavier lifts than was possible with a monohull. The larger capacity of the cranes reduced the installation time of a platform from a whole season to a few weeks. Inspired by this success similar vessels were built. In 1985 ''DB-102'' was launched for McDermott, with two cranes with a capacity of 6,000 tons each. Micoperi ordered ''M7000'' in 1986, designed with two cranes of 7,000 tons each. However, due to an oil glut in the mid 1980s, the

boom Boom may refer to: Objects * Boom (containment), a temporary floating barrier used to contain an oil spill * Boom (navigational barrier), an obstacle used to control or block marine navigation * Boom (sailing), a sailboat part * Boom (windsurfin ...

in the offshore industry was over, resulting in collaborations. In 1988, a

joint venture A joint venture (JV) is a business entity created by two or more parties, generally characterized by shared ownership, shared returns and risks, and shared governance. Companies typically pursue joint ventures for one of four reasons: to acces ...

between Heerema and McDermott was formed, HeereMac. In 1990 Micoperi had to apply for bankruptcy.

Saipem Saipem S.p.A. (Società Anonima Italiana Perforazioni E Montaggi lit. ''Drilling and Assembly Italian Public Limited Company'') is an Italian multinational oilfield services company and one of the largest in the world. Until 2016 it was a subsid ...

– in the beginning of the 1970s a large heavy lift contractor, but only a small player in this field at the end of the 1980s – acquired ''M7000'' from Micoperi in 1995, later renaming it . In 1997 Heerema took over ''DB-102'' from McDermott after discontinuation of their joint venture. The ship was renamed and, after an upgrade in 2000 to twice 7,100 tons. ''Thialf'' can use both cranes to lift at a radius of ; in comparison, ''Saipem 7000'' can use both cranes to lift a smaller load of at a wider radius of .

Lifting records

A heaviest single lift record was set in 2000 by ''Thialf'' for lifting the Shearwater topsides for Shell. ''Saipem 7000'' set a new record in October 2004 for the lift of Sabratha Deck. Under dynamic positioning, ''Saipem 7000'' set another record in 2010 by lifting the BP Valhall Production topsides. Shortly after it was completed, ''Sleipnir'' completed a record lift of for the topsides of the Leviathan project for Noble Energy, in September 2019.

Heavy lift vessels

References

External links

* ''A Gigantic Muscle of Steel: it picks up a sunken tugboat from the harbor bottom as easily as you'd lift ten pounds off the floor'',

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