A crane is a

machine A machine is a physical system that uses power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromol ...

used to move materials both vertically and horizontally, utilizing a system of a boom, hoist,

wire rope Steel wire rope (right hand lang lay) Wire rope is composed of as few as two solid, metal wires twisted into a helix that forms a composite ''rope'', in a pattern known as ''laid rope''. Larger diameter wire rope consists of multiple strands of ...

s or

chain A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A ...

s, and sheaves for lifting and relocating heavy objects within the swing of its boom. The device uses one or more

simple machine A simple machine is a machine, mechanical device that changes the Direction (geometry) , direction or Magnitude_(mathematics) , magnitude of a force. In general, they can be defined as the simplest Mechanism (engineering) , mechanisms that use ...

s, such as the

lever A lever is a simple machine consisting of a beam (structure), beam or rigid rod pivoted at a fixed hinge, or '':wikt:fulcrum, fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, l ...

and

pulley Sheave without a rope A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A pulley may have a groove or grooves between flan ...

, to create

mechanical advantage Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for ...

to do its work. Cranes are commonly employed in transportation for the loading and unloading of freight, in

construction Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...

for the movement of materials, and in manufacturing for the assembling of

heavy equipment Heavy equipment, heavy machinery, earthmovers, construction vehicles, or construction equipment, refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large con ...

. The first known crane machine was the shaduf, a water-lifting device that was invented in ancient

Mesopotamia Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. Today, Mesopotamia is known as present-day Iraq and forms the eastern geographic boundary of ...

(modern Iraq) and then appeared in

ancient Egyptian technology Ancient Egyptian technology describes devices and technologies invented or used in Ancient Egypt. The Egyptians invented and used many simple machines, such as the inclined plane, ramp and the lever, to aid construction processes. They used rope t ...

. Construction cranes later appeared in

ancient Greece Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically r ...

, where they were powered by men or animals (such as donkeys), and used for the construction of buildings. Larger cranes were later developed in the

Roman Empire The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of ...

, employing the use of human

treadwheel A treadwheel, or treadmill, is a form of engine typically powered by humans. It may resemble a water wheel in appearance, and can be worked either by a human treading paddles set into its circumference (treadmill), or by a human or animal standing ...

s, permitting the lifting of heavier weights. In the

High Middle Ages The High Middle Ages, or High Medieval Period, was the periodization, period of European history between and ; it was preceded by the Early Middle Ages and followed by the Late Middle Ages, which ended according to historiographical convention ...

, harbour cranes were introduced to load and unload ships and assist with their construction—some were built into stone towers for extra strength and stability. The earliest cranes were constructed from wood, but

cast iron Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its car ...

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

and

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

took over with the coming of the

Industrial Revolution The Industrial Revolution, sometimes divided into the First Industrial Revolution and Second Industrial Revolution, was a transitional period of the global economy toward more widespread, efficient and stable manufacturing processes, succee ...

. For many centuries, power was supplied by the physical exertion of men or animals, although hoists in

watermill A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as mill (grinding), milling (grinding), rolling, or hammering. Such processes are needed in ...

s and

windmill A windmill is a machine operated by the force of wind acting on vanes or sails to mill grain (gristmills), pump water, generate electricity, or drive other machinery. Windmills were used throughout the high medieval and early modern period ...

s could be driven by the harnessed natural power. The first ''mechanical'' power was provided by

steam engine A steam engine is a heat engine that performs Work (physics), mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a Cylinder (locomotive), cyl ...

s, the earliest

steam crane A steam crane is a crane (machine), crane powered by a steam engine. It may be fixed or mobile and, if mobile, it may run on rail tracks, caterpillar tracks, road wheels, or be mounted on a barge. It usually has a vertical boiler placed at the ...

being introduced in the 18th or 19th century, with many remaining in use well into the late 20th century. Modern cranes usually use

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal comb ...

s or

electric motor An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to gene ...

s and

hydraulic Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

systems to provide a much greater lifting capability than was previously possible, although manual cranes are still utilized where the provision of power would be uneconomic. There are many different types of cranes, each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes, used for constructing high buildings. Mini-cranes are also used for constructing high buildings, to facilitate constructions by reaching tight spaces. Large floating cranes are generally used to build oil rigs and salvage sunken ships. Some lifting machines do not strictly fit the above definition of a crane, but are generally known as cranes, such as stacker cranes and loader cranes.

Etymology

Cranes were so called from the resemblance to the long neck of the

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

, cf. , French ''grue''.

History

Ancient Near East

The first type of crane machine was the shadouf, which had a lever mechanism and was used to lift water for

irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

. It was invented in

(modern Iraq) circa 3000 BC. The shadouf subsequently appeared in

circa 2000 BC.

Ancient Greece

A crane for lifting heavy loads was developed by the

Ancient Greeks Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically re ...

in the late 6th century BC. The archaeological record shows that no later than c. 515 BC distinctive cuttings for both lifting tongs and lewis irons begin to appear on stone blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the center of gravity of the block, or in pairs equidistant from a point over the center of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane. The introduction of the

winch A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension (physics), tension of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form, it consists of a Bobb ...

and

hoist soon led to a widespread replacement of ramps as the main means of vertical motion. For the next 200 years, Greek building sites witnessed a sharp reduction in the weights handled, as the new lifting technique made the use of several smaller stones more practical than fewer larger ones. In contrast to the archaic period with its pattern of ever-increasing block sizes, Greek temples of the classical age like the

Parthenon The Parthenon (; ; ) is a former Ancient Greek temple, temple on the Acropolis of Athens, Athenian Acropolis, Greece, that was dedicated to the Greek gods, goddess Athena. Its decorative sculptures are considered some of the high points of c ...

invariably featured stone blocks weighing less than 15–20 metric tons. Also, the practice of erecting large monolithic columns was practically abandoned in favour of using several column drums. Although the exact circumstances of the shift from the ramp to the crane technology remain unclear, it has been argued that the volatile social and political conditions of

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

were more suitable to the employment of small, professional construction teams than of large bodies of unskilled labour, making the crane preferable to the Greek

polis Polis (: poleis) means 'city' in Ancient Greek. The ancient word ''polis'' had socio-political connotations not possessed by modern usage. For example, Modern Greek πόλη (polē) is located within a (''khôra''), "country", which is a πατ ...

over the more labour-intensive ramp which had been the norm in the autocratic societies of

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

Assyria Assyria (Neo-Assyrian cuneiform: , ''māt Aššur'') was a major ancient Mesopotamian civilization that existed as a city-state from the 21st century BC to the 14th century BC and eventually expanded into an empire from the 14th century BC t ...

. The first unequivocal literary evidence for the existence of the compound pulley system appears in the ''Mechanical Problems'' (''Mech''. 18, 853a32–853b13) attributed to

Aristotle Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...

(384–322 BC), but perhaps composed at a slightly later date. Around the same time, block sizes at Greek temples began to match their archaic predecessors again, indicating that the more sophisticated compound pulley must have found its way to Greek construction sites by then.

Roman Empire

The heyday of the crane in ancient times came during the

, when construction activity soared and buildings reached enormous dimensions. The Romans adopted the Greek crane and developed it further. There is much available information about their lifting techniques, thanks to rather lengthy accounts by the engineers

Vitruvius Vitruvius ( ; ; –70 BC – after ) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work titled . As the only treatise on architecture to survive from antiquity, it has been regarded since the Renaissan ...

(''De Architectura'' 10.2, 1–10) and

Heron of Alexandria Hero of Alexandria (; , , also known as Heron of Alexandria ; probably 1st or 2nd century AD) was a Greek mathematician and engineer who was active in Alexandria in Egypt during the Roman era. He has been described as the greatest experimentali ...

(''Mechanica'' 3.2–5). There are also two surviving reliefs of Roman

treadwheel crane A treadwheel crane () is a wooden, human powered hoisting and lowering device. It was primarily used during the Roman period and the Middle Ages in the building of castles and cathedrals. The often heavy charge is lifted as the individual inside ...

s, with the Haterii tombstone from the late first century AD being particularly detailed. The simplest Roman crane, the ''trispastos'', consisted of a double-beam jib, a

, a

rope A rope is a group of yarns, Plying, plies, fibres, or strands that are plying, twisted or braided together into a larger and stronger form. Ropes have high tensile strength and can be used for dragging and lifting. Rope is thicker and stronger ...

, and a block containing three pulleys. Having thus a

of 3:1, it has been calculated that a single man working the winch could raise (3 pulleys x = 150), assuming that represent the maximum effort a man can exert over a longer time period. Heavier crane types featured five pulleys (''pentaspastos'') or, in case of the largest one, a set of three by five pulleys (''Polyspastos'') and came with two, three or four masts, depending on the maximum load. The ''polyspastos'', when worked by four men at both sides of the winch, could readily lift (3 ropes x 5 pulleys x 4 men x = ). If the winch was replaced by a treadwheel, the maximum load could be doubled to at only half the crew, since the treadwheel possesses a much bigger mechanical advantage due to its larger diameter. This meant that, in comparison to the construction of the

ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...

ian

pyramids A pyramid () is a Nonbuilding structure, structure whose visible surfaces are triangular in broad outline and converge toward the top, making the appearance roughly a Pyramid (geometry), pyramid in the geometric sense. The base of a pyramid ca ...

, where about 50 men were needed to move a 2.5 ton stone block up the ramp ( per person), the lifting capability of the Roman ''polyspastos'' proved to be ''60 times'' higher ( per person). However, numerous extant Roman buildings which feature much heavier stone blocks than those handled by the ''polyspastos'' indicate that the overall lifting capability of the Romans went far beyond that of any single crane. At the temple of Jupiter at

Baalbek Baalbek (; ; ) is a city located east of the Litani River in Lebanon's Beqaa Valley, about northeast of Beirut. It is the capital of Baalbek-Hermel Governorate. In 1998, the city had a population of 82,608. Most of the population consists of S ...

, for instance, the

architrave In classical architecture, an architrave (; , also called an epistyle; ) is the lintel or beam, typically made of wood or stone, that rests on the capitals of columns. The term can also apply to all sides, including the vertical members, ...

blocks weigh up to 60 tons each, and one corner

cornice In architecture, a cornice (from the Italian ''cornice'' meaning "ledge") is generally any horizontal decorative Moulding (decorative), moulding that crowns a building or furniture element—for example, the cornice over a door or window, ar ...

block even over 100 tons, all of them raised to a height of about . In

Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

, the capital block of Trajan's Column weighs 53.3 tons, which had to be lifted to a height of about (see construction of Trajan's Column). It is assumed that Roman engineers lifted these extraordinary weights by two measures (see picture below for comparable Renaissance technique): First, as suggested by Heron, a lifting tower was set up, whose four masts were arranged in the shape of a quadrangle with parallel sides, not unlike a

siege tower A Roman siege tower or breaching tower (or in the Middle Ages, a belfry''Castle: Stephen Biesty's Cross-Sections''. Dorling Kindersley Pub (T); 1st American edition (September 1994). Siege towers were invented in 300 BC. ) is a specialized siege ...

, but with the column in the middle of the structure (''Mechanica'' 3.5). Second, a multitude of capstans were placed on the ground around the tower, for, although having a lower leverage ratio than treadwheels, capstans could be set up in higher numbers and run by more men (and, moreover, by draught animals). This use of multiple capstans is also described by

Ammianus Marcellinus Ammianus Marcellinus, occasionally anglicized as Ammian ( Greek: Αμμιανός Μαρκελλίνος; born , died 400), was a Greek and Roman soldier and historian who wrote the penultimate major historical account surviving from antiquit ...

(17.4.15) in connection with the lifting of the Lateranense obelisk in the

Circus Maximus The Circus Maximus (Latin for "largest circus"; Italian language, Italian: ''Circo Massimo'') is an ancient Roman chariot racing, chariot-racing stadium and mass entertainment venue in Rome, Italy. In the valley between the Aventine Hill, Avent ...

(c. 357 AD). The maximum lifting capability of a single capstan can be established by the number of lewis iron holes bored into the monolith. In case of the Baalbek architrave blocks, which weigh between 55 and 60 tons, eight extant holes suggest an allowance of 7.5 ton per lewis iron, that is per capstan. Lifting such heavy weights in a concerted action required a great amount of coordination between the work groups applying the force to the capstans. Pl gdansk zuraw dlugiepobrzeze2006

Middle Ages

During the

, the treadwheel crane was reintroduced on a large scale after the technology had fallen into disuse in western Europe with the demise of the

Western Roman Empire In modern historiography, the Western Roman Empire was the western provinces of the Roman Empire, collectively, during any period in which they were administered separately from the eastern provinces by a separate, independent imperial court. ...

. The earliest reference to a treadwheel (''magna rota'') reappears in archival literature in France about 1225, followed by an illuminated depiction in a manuscript of probably also French origin dating to 1240. In navigation, the earliest uses of harbor cranes are documented for

Utrecht Utrecht ( ; ; ) is the List of cities in the Netherlands by province, fourth-largest city of the Netherlands, as well as the capital and the most populous city of the Provinces of the Netherlands, province of Utrecht (province), Utrecht. The ...

in 1244,

Antwerp Antwerp (; ; ) is a City status in Belgium, city and a Municipalities of Belgium, municipality in the Flemish Region of Belgium. It is the capital and largest city of Antwerp Province, and the third-largest city in Belgium by area at , after ...

in 1263,

Bruges Bruges ( , ; ; ) is the capital and largest city of the province of West Flanders, in the Flemish Region of Belgium. It is in the northwest of the country, and is the sixth most populous city in the country. The area of the whole city amoun ...

in 1288 and

Hamburg Hamburg (, ; ), officially the Free and Hanseatic City of Hamburg,. is the List of cities in Germany by population, second-largest city in Germany after Berlin and List of cities in the European Union by population within city limits, 7th-lar ...

in 1291, while in England the treadwheel is not recorded before 1331. Generally, vertical transport could be done more safely and inexpensively by cranes than by customary methods. Typical areas of application were harbors, mines, and, in particular, building sites where the treadwheel crane played a pivotal role in the construction of the lofty

Gothic cathedrals Gothic cathedrals and churches are religious buildings constructed in Europe in Gothic style between the mid-12th century and the beginning of the 16th century. The cathedrals are notable particularly for their great height and their extensive u ...

. Nevertheless, both archival and pictorial sources of the time suggest that newly introduced machines like treadwheels or

wheelbarrow A wheelbarrow is a small hand-propelled load-bearing vehicle, usually with just one wheel, designed to be pushed and guided by a single person using two handles at the rear. The term "wheelbarrow" is made of two words: "wheel" and "barrow." " Ba ...

s did not completely replace more labor-intensive methods like ladders, hods and

handbarrow The handbarrow, also spelled hand-barrow and hand barrow, is a type of human-powered transport Human-powered transport is the transport of passenger, person(s) and/or goods (freight) using human power, human muscle power. Unlike animal-powered ...

s. Rather, old and new machinery continued to coexist on medieval construction sites and harbors. Apart from treadwheels, medieval depictions also show cranes to be powered manually by windlasses with radiating

spoke A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface. The term originally referred to portions of a log that had been riven (split ...

s, cranks and by the 15th century also by windlasses shaped like a

ship's wheel A ship's wheel or boat's wheel is a device used aboard a ship, boat, submarine, or airship, with which a helmsman steering, steers the vessel and controls its course (navigation), course. Together with the rest of the steering mechanism, it forms ...

. To smooth out irregularities of impulse and get over 'dead-spots' in the lifting process

flywheel A flywheel is a mechanical device that uses the conservation of angular momentum to store rotational energy, a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, a ...

s are known to be in use as early as 1123. The exact process by which the treadwheel crane was reintroduced is not recorded, although its return to construction sites has undoubtedly to be viewed in close connection with the simultaneous rise of Gothic architecture. The reappearance of the treadwheel crane may have resulted from a technological development of the

windlass The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound arou ...

from which the treadwheel structurally and mechanically evolved. Alternatively, the medieval treadwheel may represent a deliberate reinvention of its Roman counterpart drawn from

' ''

De architectura (''On architecture'', published as ''Ten Books on Architecture'') is a treatise on architecture written by the Ancient Rome, Roman architect and military engineer Vitruvius, Marcus Vitruvius Pollio and dedicated to his patron, the emperor Caesa ...

'' which was available in many monastic libraries. Its reintroduction may have been inspired, as well, by the observation of the labor-saving qualities of the

waterwheel A water wheel is a machine for converting the kinetic energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a large wheel (usually constructed from wood or metal), with numerous blade ...

with which early treadwheels shared many structural similarities.

Structure and placement

The medieval treadwheel was a large wooden wheel turning around a central shaft with a treadway wide enough for two workers walking side by side. While the earlier 'compass-arm' wheel had spokes directly driven into the central shaft, the more advanced "clasp-arm" type featured arms arranged as chords to the wheel rim, giving the possibility of using a thinner shaft and providing thus a greater mechanical advantage. Reconstruction of the temple of Jerusalem

Reconstruction of the temple of Jerusalem

Contrary to a popularly held belief, cranes on medieval building sites were neither placed on the extremely lightweight

scaffolding Scaffolding, also called scaffold or staging, is a temporary structure used to support a work crew and materials to aid in the construction, maintenance and repair of buildings, bridges and all other human-made structures. Scaffolds are widely u ...

used at the time nor on the thin walls of the Gothic churches which were incapable of supporting the weight of both hoisting machine and load. Rather, cranes were placed in the initial stages of construction on the ground, often within the building. When a new floor was completed, and massive tie beams of the roof connected the walls, the crane was dismantled and reassembled on the roof beams from where it was moved from bay to bay during construction of the vaults. Thus, the crane "grew" and "wandered" with the building with the result that today all extant construction cranes in England are found in church towers above the vaulting and below the roof, where they remained after building construction for bringing material for repairs aloft. Less frequently, medieval illuminations also show cranes mounted on the outside of walls with the stand of the machine secured to putlogs.

Mechanics and operation

In contrast to modern cranes, medieval cranes and hoists — much like their counterparts in Greece and Rome — were primarily capable of a vertical lift, and not used to move loads for a considerable distance horizontally as well. Accordingly, lifting work was organized at the workplace in a different way than today. In building construction, for example, it is assumed that the crane lifted the stone blocks either from the bottom directly into place, or from a place opposite the centre of the wall from where it could deliver the blocks for two teams working at each end of the wall. Additionally, the crane master who usually gave orders at the treadwheel workers from outside the crane was able to manipulate the movement laterally by a small rope attached to the load. Slewing cranes which allowed a rotation of the load and were thus particularly suited for dockside work appeared as early as 1340. While ashlar blocks were directly lifted by sling, lewis or devil's clamp (German ''Teufelskralle''), other objects were placed before in containers like

pallet A pallet (also called a skid) is a flat transport structure, which supports goods in a stable fashion while being lifted by a forklift, a pallet jack, a Loader (equipment), front loader, a Jack (mechanical), jacking device, or an erect cra ...

basket A basket is a container that is traditionally constructed from stiff Fiber, fibers, and can be made from a range of materials, including wood splints, Stolon, runners, and cane. While most baskets are made from plant materials, other materials ...

s, wooden boxes or

barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden stave (wood), staves and bound by wooden or metal hoops. The word vat is often used for large containers ...

s. It is noteworthy that medieval cranes rarely featured ratchets or

brake A brake is a machine, mechanical device that inhibits motion by absorbing energy from a moving system. It is used for Acceleration, slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of ...

s to forestall the load from running backward. This curious absence is explained by the high friction force exercised by medieval tread-wheels which normally prevented the wheel from accelerating beyond control.

Harbour usage

According to the "present state of knowledge" unknown in antiquity, stationary harbor cranes are considered a new development of the Middle Ages. The typical harbor crane was a pivoting structure equipped with double treadwheels. These cranes were placed docksides for the loading and unloading of cargo where they replaced or complemented older lifting methods like

see-saw A seesaw (also sometimes known as a teeter-totter in North America) is a long, narrow board supported by a single pivot point, most commonly located at the midpoint between both ends; as one end goes up, the other goes down. These are most comm ...

es and

yards The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...

. Two different types of harbor cranes can be identified with a varying geographical distribution: While gantry cranes, which pivoted on a central vertical axle, were commonly found at the Flemish and Dutch coastside, German sea and inland harbors typically featured tower cranes where the windlass and treadwheels were situated in a solid tower with only jib arm and roof rotating. Dockside cranes were not adopted in the Mediterranean region and the highly developed Italian ports where authorities continued to rely on the more labor-intensive method of unloading goods by ramps beyond the Middle Ages. Unlike construction cranes where the work speed was determined by the relatively slow progress of the masons, harbor cranes usually featured double treadwheels to speed up loading. The two treadwheels whose diameter is estimated to be 4 m or larger were attached to each side of the axle and rotated together. Their capacity was 2–3 tons, which apparently corresponded to the customary size of marine cargo. Today, according to one survey, fifteen treadwheel harbor cranes from pre-industrial times are still extant throughout Europe. Some harbour cranes were specialised at mounting masts to newly built sailing ships, such as in

Gdańsk Gdańsk is a city on the Baltic Sea, Baltic coast of northern Poland, and the capital of the Pomeranian Voivodeship. With a population of 486,492, Data for territorial unit 2261000. it is Poland's sixth-largest city and principal seaport. Gdań ...

Cologne Cologne ( ; ; ) is the largest city of the States of Germany, German state of North Rhine-Westphalia and the List of cities in Germany by population, fourth-most populous city of Germany with nearly 1.1 million inhabitants in the city pr ...

and

Bremen Bremen (Low German also: ''Breem'' or ''Bräm''), officially the City Municipality of Bremen (, ), is the capital of the States of Germany, German state of the Bremen (state), Free Hanseatic City of Bremen (), a two-city-state consisting of the c ...

. Beside these stationary cranes, floating cranes, which could be flexibly deployed in the whole port basin came into use by the 14th century. A

sheer hulk A hulk is a ship that is afloat, but incapable of going to sea. 'Hulk' may be used to describe a ship that has been launched but not completed, an abandoned wreck or shell, or a ship whose propulsion system is no longer maintained or has been r ...

(or shear hulk) was used in shipbuilding and repair as a floating crane in the days of

sailing ship A sailing ship is a sea-going vessel that uses sails mounted on Mast (sailing), masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing Square rig, square-rigged or Fore-an ...

s, primarily to place the lower

mast Mast, MAST or MASt may refer to: Engineering * Mast (sailing), a vertical spar on a sailing ship * Flagmast, a pole for flying a flag * Guyed mast, a structure supported by guy-wires * Mooring mast, a structure for docking an airship * Radio mas ...

s of a ship under construction or repair. Booms known as

sheers 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 ...

were attached to the base of a hulk's lower masts or beam, supported from the top of those masts. Blocks and tackle were then used in such tasks as placing or removing the lower masts of the vessel under construction or repair. These lower masts were the largest and most massive single timbers aboard a ship, and erecting them without the assistance of either a sheer hulk or land-based

masting sheer A masting sheer, sheers, shears or masting crane is a specialised shipyard crane, intended for placing tall masts onto large sailing ships. "Sheers" is an old name for a fixed crane formed by one or two wooden beams, fixed at the base and supporte ...

was extremely difficult. The concept of sheer hulks originated with the Royal Navy in the 1690s, and persisted in Britain until the early nineteenth century. Most sheer hulks were decommissioned warships; ''Chatham'', built in 1694, was the first of only three purpose-built vessels. There were at least six sheer hulks in service in Britain at any time throughout the 1700s. The concept spread to France in the 1740s with the commissioning of a sheer hulk at the port of Rochefort.

Early modern age

A lifting tower similar to that of the ancient Romans was used to great effect by the Renaissance architect

Domenico Fontana Domenico Fontana (154328 June 1607) was an Italian"Domenico Fontana."
''

Vatican obelisk The Vatican Obelisk is an List of Egyptian obelisks, Egyptian obelisk, one of the thirteen ancient List of obelisks in Rome, obelisks of Rome. This obelisk is located in St. Peter's Square, in Vatican City. It is the only ancient obelisk in Rome t ...

in Rome. From his report, it becomes obvious that the coordination of the lift between the various pulling teams required a considerable amount of concentration and discipline, since, if the force was not applied evenly, the excessive stress on the ropes would make them rupture. Cranes were also used domestically during this period. The chimney or fireplace crane was used to swing pots and kettles over the fire and the height was adjusted by a trammel. File:1586 Rome obelisk erection.jpg, Erection of the

in 1586 by means of a lifting tower File:Kölner Dom 1868 001.jpg, alt=Old photo of a 15th-century crane on the south tower of the cathedral before completion, An 1868 photo of a 15th-century crane on the unfinished south tower of

Cologne Cathedral Cologne Cathedral (, , officially , English: Cathedral Church of Saint Peter) is a cathedral in Cologne, North Rhine-Westphalia belonging to the Catholic Church. It is the seat of the Archbishop of Cologne and of the administration of the Archd ...

File:Fireplace crane02.jpg, Fireplace crane

Industrial revolution

With the onset of the

the first modern cranes were installed at harbours for loading cargo. In 1838, the industrialist and businessman William Armstrong designed a water-powered hydraulic crane. His design used a ram in a closed cylinder that was forced down by a pressurized fluid entering the cylinder and a valve regulated the amount of fluid intake relative to the load on the crane. This mechanism, the hydraulic jigger, then pulled on a chain to lift the load. In 1845 a scheme was set in motion to provide piped water from distant reservoirs to the households of

Newcastle Newcastle usually refers to: *Newcastle upon Tyne, a city and metropolitan borough in Tyne and Wear, England, United Kingdom *Newcastle-under-Lyme, a town in Staffordshire, England, United Kingdom *Newcastle, New South Wales, a metropolitan area ...

. Armstrong was involved in this scheme and he proposed to Newcastle Corporation that the excess water pressure in the lower part of town could be used to power one of his hydraulic cranes for the loading of coal onto barges at the

Quayside The Quayside is an area along the banks (quay) of the River Tyne in Newcastle upon Tyne (the north bank) and Gateshead (south bank) in Tyne and Wear, North East England, United Kingdom. History The area was once an industrial area and busy c ...

. He claimed that his invention would do the job faster and more cheaply than conventional cranes. The corporation agreed to his suggestion, and the experiment proved so successful that three more hydraulic cranes were installed on the Quayside. The success of his hydraulic crane led Armstrong to establish the Elswick works at

, to produce his

hydraulic machinery Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine a ...

for cranes and bridges in 1847. His company soon received orders for hydraulic cranes from Edinburgh and Northern Railways and from

Liverpool Docks The Port of Liverpool is the enclosed Dock (maritime), dock system that runs from Brunswick Dock in Liverpool to Seaforth Dock, Seaforth, Merseyside, Seaforth, on the east side of the River Mersey and the Great Float, Birkenhead Docks betwee ...

, as well as for hydraulic machinery for dock gates in

Grimsby Grimsby or Great Grimsby is a port town in Lincolnshire, England with a population of 86,138 (as of 2021). It is located near the mouth on the south bank of the Humber that flows to the North Sea. Grimsby adjoins the town of Cleethorpes dir ...

. The company expanded from a workforce of 300 and an annual production of 45 cranes in 1850, to almost 4,000 workers producing over 100 cranes per year by the early 1860s. Armstrong spent the next few decades constantly improving his crane design; his most significant innovation was the

hydraulic accumulator A hydraulic accumulator is a pressure storage reservoir in which an Incompressible flow, incompressible hydraulic fluid is held under pressure that is applied by an external Prime mover (engine), source of mechanical energy. The external source can ...

. Where water pressure was not available on site for the use of hydraulic cranes, Armstrong often built high water towers to provide a supply of water at pressure. However, when supplying cranes for use at New Holland on the

Humber Estuary The Humber is a large tidal estuary on the east coast of Northern England. It is formed at Trent Falls, Faxfleet, by the confluence of the tidal rivers River Ouse, Yorkshire, Ouse and River Trent, Trent. From there to the North Sea, it forms ...

, he was unable to do this, because the foundations consisted of sand. He eventually produced the hydraulic accumulator, a cast-iron cylinder fitted with a plunger supporting a very heavy weight. The plunger would slowly be raised, drawing in water, until the downward force of the weight was sufficient to force the water below it into pipes at great pressure. This invention allowed much larger quantities of water to be forced through pipes at a constant pressure, thus increasing the crane's load capacity considerably. One of his cranes, commissioned by the

Italian Navy The Italian Navy (; abbreviated as MM) is one of the four branches of Italian Armed Forces and was formed in 1946 from what remained of the ''Regia Marina'' (Royal Navy) after World War II. , the Italian Navy had a strength of 30,923 active per ...

in 1883 and in use until the mid-1950s, is still standing in

Venice Venice ( ; ; , formerly ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are li ...

, where it is now in a state of disrepair.

Mechanical principles

There are three major considerations in the design of cranes. First, the crane must be able to lift the weight of the load; second, the crane must not topple; third, the crane must not fail structurally. File:El movimiento de una grua.ogg, A

tower crane A crane is a machine used to move materials both vertically and horizontally, utilizing a system of a boom, hoist, wire ropes or chains, and sheaves for lifting and relocating heavy objects within the swing of its boom. The device uses on ...

can "swing" its boom left and right, "dolly" its car (or traveler) in and out, and lift and lower its load File:Shipyard Ishibras Ishikawajima Sermetal.JPG, Failed crane in Sermetal Shipyard, former Ishikawajima do Brasil –

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

, caused by a lack of maintenance and misuse of the equipment File:Automated Crane With Utensils.jpg, Cranes can mount many different fittings, such as hooks, blocks, spreader bars, and "choker" lines, depending on load (left). Cranes can be remote-controlled from the ground, allowing much more precise control, at the expense of the view from atop the crane (right).

Stability

For stability, the sum of all moments about the base of the crane must be close to zero so that the crane does not overturn. In practice, the magnitude of load that is permitted to be lifted (called the "rated load" in the US) is some value less than the load that will cause the crane to tip, thus providing a safety margin. Under United States standards for mobile cranes, the stability-limited rated load for a crawler crane is 75% of the tipping load. The stability-limited rated load for a mobile crane supported on outriggers is 85% of the tipping load. These requirements, along with additional safety-related aspects of crane design, are established by the American Society of Mechanical Engineers in the volume ASME B30.5-2018 ''Mobile and Locomotive Cranes''. Standards for cranes mounted on ships or offshore platforms are somewhat stricter because of the dynamic load on the crane due to vessel motion. Additionally, the stability of the vessel or platform must be considered. For stationary pedestal or kingpost mounted cranes, the moment produced by the boom, jib, and load is resisted by the pedestal base or kingpost. Stress within the base must be less than the yield stress of the material or the crane will fail.

Dynamic Lift Factor

Overview

The dynamic lift factor (DLF), also known as the design dynamic factor, is a critical parameter in the crane design and operation. It accounts for the dynamic effects that can increase the load on a crane's structure and components during lifting operations. These effects include: * Hoisting acceleration and deceleration of the load, which is a significant factor; * Crane movement such as slewing or luffing; * Load swinging; * Wind forces acting on the crane, the load and the rigging; and * Operator error or other unexpected events. The DLF for a new crane design can be determined with analytical calculations and mathematical models following the relevant design

specifications A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard. There are different types of technical or engineering specificati ...

. If available, data from previous tests of similar crane types can be used to estimate the DLF. More sophisticated methods, such as

finite element analysis Finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical models, mathematical modeling. Typical problem areas of interest include the traditional fields of structural ...

or other simulation techniques, may also be used to model the crane's behavior under various loading conditions, as deemed appropriate by the designer or certifying authority.To verify the actual DLF, control load tests can be conducted on the completed crane using instrumentation such as load cells,

accelerometers An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration (the rate of change of velocity) of the object relative to an observer who is in free fall (that is, relative to an inertia ...

, and

strain gauges A strain gauge (also spelled strain gage) is a device used to measure strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an insulating flexible backing which support ...

. This process is usually part of the crane's

type approval Type approval or certificate of conformity is granted to a product that meets a minimum set of regulatory, technical and safety requirements. Generally, type approval is required before a product is allowed to be sold in a particular country, so ...

. In offshore lifting, where the crane and/or lifted object are on a floating vessel, the DLF is higher compared to onshore lifts because of the additional movement caused by wave action. This motion introduces additional acceleration forces and necessitates increased hoisting and lowering speeds to minimize the risk of repeated collisions when the load is near the deck. Additionally, the DLF increases further when lifting objects that are underwater or going through the splash zone. The wind speeds tend to be higher than onshore as well. Though actual DLF values are determined through crane tests under representative operational conditions, design specifications can be used for guidance. The values vary according to the specification, which reflects the type of crane and its usage. Here are some example typical values: * Jib cranes typically have a lower DLF (

\psi\approx1.3

) compared to traveling gantry cranes (

\psi \approx 1.6

) because they are stiffer; * For grab cranes, the DLF can increase by 20% to 30% reflecting the shock loads caused by the release of the lifted material; and * The DLF generally decreases as the mass of the lifted object increases, as cranes tend to operate at lower velocities with heavier loads to ensure safety and stability. For offshore lifts, the DLF typically decreases from 1.3 at 100 tonnes to 1.1 at 2500 tonnes.

Formulas

The methods for determining the DLF vary in the different crane specifications. The following formulas are examples from one specification. The working load (suspended load) is the total weight that a crane is designed to safely lift under normal operating conditions. It is

W= g\cdot(m_ + m_a)

where :

W

is the working load, :

g

is the acceleration of gravity, :

m_

is the maximum lifted mass, which is also called the crane working load limit (WLL) or safe working load (SWL), and :

m_a

is the mass of lifting appliances or parts of the crane that move with the lifted mass. The DLF is then used as a multiplier to determine the force applied to the crane structure and components

$F_d= \psi\ \cdot W$

where :

F_d

is the design force, and :

\psi

is the DLF. The DLF can then be calculated using

$\psi=1+V_R\cdot\sqrt$

where :

V_R

is relative velocity between lifted object and hook at the time of pick-up, and :

C

is the stiffness of the crane system at the hook. The relative velocity is dependent on the crane's operational requirements and the system stiffness at the hook can be determined by calculation or load deflection tests.

Types

The crane types outlined in this section are categorized based on their primary area of application: *

Construction Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...

** Truck-mounted ** Telescopic ** Rough-terrain ** All-terrain ** Crawler ** Pick-and-carry ** Carry deck **

Telescopic handler A telescopic handler, also called a telehandler, teleporter, reach forklift, or zoom boom, is a machine widely used in agriculture and industry. It is somewhat like a forklift but has a boom (telescopic cylinder), making it more a crane than ...

** Block setting **

Tower A tower is a tall Nonbuilding structure, structure, taller than it is wide, often by a significant factor. Towers are distinguished from guyed mast, masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting ...

** Climbing crane * Cargo handling **

Loader Loader can refer to: * Loader (equipment) * Loader (computing) ** LOADER.EXE, an auto-start program loader optionally used in the startup process of Microsoft Windows ME * Loader (surname) * Fast loader * Speedloader * Boot loader ** LOADER.COM ...

Reach stacker A reach stacker is a vehicle used for handling intermodal cargo containers in small terminals or medium-sized ports. Reach stackers can transport a container short distances very quickly and pile them in various rows depending on their access. R ...

Sidelifter A sidelifter is a specialised vehicle or semi-trailer used to hoist and transport International Organization for Standardization, ISO standard intermodal containers over longer distances. Overview The sidelifter loads and unloads containers via a ...

** Straddle carrier * Industrial **

Ring (The) Ring(s) may refer to: * Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry * To make a sound with a bell, and the sound made by a bell Arts, entertainment, and media Film and TV * ''The Ring'' (franchise), a ...

** Hammerhead ** Level luffing ** Overhead **

Gantry A gantry is an overhead bridge-like structure supporting equipment such as a crane, signals, or cameras. Devices and structures *Gantry (medical), cylindrical scanner assembly used for medical 3D-imaging or treatment *Gantry (transport), an over ...

Jib A jib is a triangular sail that sets ahead of the foremast of a sailing vessel. Its forward corner (tack) is fixed to the bowsprit, to the bows, or to the deck between the bowsprit and the foremost mast. Jibs and spinnakers are the two main ty ...

** Bulk handling **

Stacker Stac Electronics, originally incorporated as State of the Art Consulting and later shortened to Stac, Inc., was a technology company founded in 1983. It is known primarily for its Lempel–Ziv–Stac lossless compression algorithm and Stacker ...

Wind turbine installation vessel A wind turbine installation vessel (WTIV) is a vessel specifically designed for the installation of offshore wind turbines. There were 16 such vessels in 2020. Most are self-elevating jackup rigs. To enable quick relocation in the wind farm it is ...

* Marine ** Floating ** Deck * Other types **

Railroad Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

** Aerial

Construction

Truck-mounted

The most basic

truck A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...

-mounted crane configuration is a "boom truck" or "lorry loader", which features a rear-mounted rotating telescopic-boom crane mounted on a commercial truck chassis. Tram repair in Dnipro

Larger, heavier duty, purpose-built "truck-mounted" cranes are constructed in two parts: the carrier, often called the ''lower'', and the lifting component, which includes the boom, called the ''upper''. These are mated together through a turntable, allowing the upper to swing from side to side. These modern hydraulic truck cranes are usually single-engine machines, with the same engine powering the undercarriage and the crane. The upper is usually powered via hydraulics run through the turntable from the pump mounted on the lower. In older model designs of hydraulic truck cranes, there were two engines. One in the lower pulled the crane down the road and ran a hydraulic pump for the outriggers and jacks. The one in the upper ran the upper through a hydraulic pump of its own. Many older operators favor the two-engine system due to leaking seals in the turntable of aging newer design cranes. Hiab invented the world's first hydraulic truck mounted crane in 1947. The name, Hiab, comes from the commonly used abbreviation of Hydrauliska Industri AB, a company founded in Hudiksvall, Sweden 1944 by Eric Sundin, a ski manufacturer who saw a way to utilize a truck's engine to power loader cranes through the use of hydraulics. Generally, these cranes are able to travel on highways, eliminating the need for special equipment to transport the crane unless weight or other size constrictions are in place such as local laws. If this is the case, most larger cranes are equipped with either special trailers to help spread the load over more axles or are able to disassemble to meet requirements. An example is counterweights. Often a crane will be followed by another truck hauling the counterweights that are removed for travel. In addition some cranes are able to remove the entire upper. However, this is usually only an issue in a large crane and mostly done with a conventional crane such as a Link-Belt HC-238. When working on the job site,

outrigger An outrigger is a projecting structure on a boat, with specific meaning depending on types of vessel. Outriggers may also refer to legs on a wheeled vehicle that are folded out when it needs stabilization, for example on a crane that lifts he ...

s are extended horizontally from the chassis then vertically to level and stabilize the crane while stationary and hoisting. Many truck cranes have slow-travelling capability (a few miles per hour) while suspending a load. Great care must be taken not to swing the load sideways from the direction of travel, as most anti-tipping stability then lies in the stiffness of the chassis suspension. Most cranes of this type also have moving counterweights for stabilization beyond that provided by the outriggers. Loads suspended directly aft are the most stable, since most of the weight of the crane acts as a counterweight. Factory-calculated charts (or electronic safeguards) are used by crane operators to determine the maximum safe loads for stationary (outriggered) work as well as (on-rubber) loads and travelling speeds. Truck cranes range in lifting capacity from about to about . Although most only rotate about 180 degrees, the more expensive truck mounted cranes can turn a full 360 degrees. File:Автомобильный кран Железнодорожных войск РФ.png, Automobile crane of the Railway Troops of Russia File:Truck-mounted crane building a bridge.jpg, Truck mounted crane building a bridge File:Truck crane.jpg, A truck-mounted crane in road travel configuration

Loader

A loader crane (also called a '' knuckle-boom crane'' or ''articulating crane'') is a hydraulically powered articulated arm fitted to a

or trailer, and is used for loading/unloading the vehicle cargo. The numerous jointed sections can be folded into a small space when the crane is not in use. One or more of the sections may be telescopic. Often the crane will have a degree of automation and be able to unload or stow itself without an operator's instruction. Unlike most cranes, the operator must move around the vehicle to be able to view his load; hence modern cranes may be fitted with a portable cabled or radio-linked control system to supplement the crane-mounted hydraulic control levers. In the United Kingdom and Canada, this type of crane is often known colloquially as a "

Hiab Hydrauliska Industri AB (Hiab) is a Swedish manufacturer of loader cranes, demountable container handlers, forestry cranes, knuckle boom cranes, truck-mounted forklifts and tail lifts. The company is owned by the Cargotec Corporation. Hist ...

", partly because this manufacturer invented the loader crane and was first into the UK market, and partly because the distinctive name was displayed prominently on the boom arm. A rolloader crane is a loader crane mounted on a chassis with wheels. This chassis can ride on the trailer. Because the crane can move on the trailer, it can be a light crane, so the trailer is allowed to transport more goods.

Telescopic

A telescopic crane has a boom that consists of a number of tubes fitted one inside the other. A

hydraulic cylinder A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment ( engineering vehicles ...

or other powered mechanism extends or retracts the tubes to increase or decrease the total length of the boom. These types of booms are often used for short term construction projects, rescue jobs, lifting boats in and out of the water, etc. The relative compactness of telescopic booms makes them adaptable for many mobile applications. Though not all telescopic cranes are mobile cranes, many of them are truck-mounted. A telescopic tower crane has a telescopic mast and often a superstructure (jib) on top so that it functions as a tower crane. Some telescopic tower cranes also have a telescopic jib.

Rough-terrain

A rough terrain crane has a boom mounted on an undercarriage atop four rubber tires that is designed for

off-road Off-roading is the act of driving or riding in a vehicle on unpaved surfaces such as sand, dirt, gravel, riverbeds, mud, snow, rocks, or other natural terrain. Off-roading ranges from casual drives with regular vehicles to competitive events w ...

pick-and-carry operations. Outriggers are used to level and stabilize the crane for hoisting. These telescopic cranes are single-engine machines, with the same engine powering the undercarriage and the crane, similar to a crawler crane. The engine is usually mounted in the undercarriage rather than in the upper, as with crawler crane. Most have 4 wheel drive and 4 wheel steering for traversing tighter and slicker terrain than a standard truck crane, with less site prep.

All-terrain

An all-terrain crane is a hybrid combining the roadability of a truck-mounted and on-site maneuverability of a rough-terrain crane. It can both travel at speed on public roads and maneuver on rough terrain at the job site using all-wheel and crab steering. AT's have 2–12 axles and are designed for lifting loads up to .

Crawler

Main article: Lattice boom crawler crane Crawler crane 2

A crawler crane has its boom mounted on an undercarriage fitted with a set of crawler tracks that provide both stability and mobility. Crawler cranes range in lifting capacity from about as seen from the

XGC88000 crawler crane The XGC88000 crawler crane is a class of extremely large ultraheavy crawler crane made by XCMG. With a lifting capacity of 3,600 to 4,000 tons, a total boom length of 144 meters and a total gross weight of 5,350 tons. The XGC88000 crawler crane ...

. The main advantage of a crawler crane is its ready mobility and use, since the crane is able to operate on sites with minimal improvement and stable on its tracks without outriggers. Wide tracks spread the weight out over a great area and are far better than wheels at traversing soft ground without sinking in. A crawler crane is also capable of traveling with a load. Its main disadvantage is its weight, making it difficult and expensive to transport. Typically a large crawler must be disassembled at least into boom and cab and moved by trucks, rail cars or ships to its next location.

Pick-and-carry

A pick and carry crane is similar to a mobile crane in that is designed to travel on public roads; however, pick and carry cranes have no stabiliser legs or outriggers and are designed to lift the load and carry it to its destination, within a small radius, then be able to drive to the next job. Pick and carry cranes are popular in Australia, where large distances are encountered between job sites. One popular manufacturer in Australia was Franna, who have since been bought by Terex, and now all pick and carry cranes are commonly called "Frannas", even though they may be made by other manufacturers. Nearly every medium- and large-sized crane company in Australia has at least one and many companies have fleets of these cranes. The capacity range is between as a maximum lift, although this is much less as the load gets further from the front of the crane. Pick and carry cranes have displaced the work usually completed by smaller truck cranes, as the set-up time is much quicker. Many steel fabrication yards also use pick and carry cranes, as they can "walk" with fabricated steel sections and place these where required with relative ease. Smaller pick and carry cranes may be based on an articulated tractor chassis, with the boom mounted over the front wheels. In Australia these are popularly known as "wobbly cranes".

Carry-deck

A carry deck crane is a small 4 wheel crane with a 360-degree rotating boom placed right in the centre and an operators cab located at one end under this boom. The rear section houses the engine and the area above the wheels is a flat deck. Very much an American invention the Carry deck can hoist a load in a confined space and then load it on the deck space around the cab or engine and subsequently move to another site. The Carry Deck principle is the American version of the pick and carry crane and both allow the load to be moved by the crane over short distances.

Telescopic handler

Telescopic handlers are

forklift A forklift (also called industrial truck, lift truck, jitney, hi-lo, fork truck, fork hoist, and forklift truck) is a powered industrial truck used to lift and move materials over short distances. The forklift was developed in the early 20th c ...

-like trucks that have a set of forks mounted on a telescoping extendable boom like a crane. Early telescopic handlers only lifted in one direction and did not rotate; however, several of the manufacturers have designed telescopic handlers that rotate 360 degrees through a turntable and these machines look almost identical to the Rough Terrain Crane. These new 360-degree telescopic handler/crane models have outriggers or stabiliser legs that must be lowered before lifting; however, their design has been simplified so that they can be more quickly deployed. These machines are often used to handle pallets of bricks and install frame trusses on many new building sites and they have eroded much of the work for small telescopic truck cranes. Many of the world's armed forces have purchased telescopic handlers and some of these are the much more expensive fully rotating types. Their off-road capability and their on site versatility to unload pallets using forks, or lift like a crane make them a valuable piece of machinery.

Block-setting crane

A block-setting crane is a form of crane. They were used for installing the large stone blocks used to build

breakwaters A breakwater is a permanent structure constructed at a coastal area to protect against tides, currents, waves, and storm surges. Breakwaters have been built since antiquity to protect anchorages, helping isolate vessels from marine hazards ...

, moles and stone piers.

Tower

Tower cranes are a modern form of balance crane that consist of the same basic parts. Fixed to the ground on a concrete slab (and sometimes attached to the sides of structures), tower cranes often give the best combination of height and lifting capacity and are used in the construction of tall buildings. The base is then attached to the mast which gives the crane its height. Further, the mast is attached to the slewing unit (gear and motor) that allows the crane to rotate. On top of the slewing unit there are three main parts which are: the long horizontal jib (working arm), shorter counter-jib, and the operator's cab. Optimization of tower crane location in the construction sites has an important effect on material transportation costs of a project, but site operators need to ensure they assess where the jib will oversail the property of other landowners and tenants as it rotates over the site. Under

English law English law is the common law list of national legal systems, legal system of England and Wales, comprising mainly English criminal law, criminal law and Civil law (common law), civil law, each branch having its own Courts of England and Wales, ...

a landowner also owns the airspace above their property and developers will need to agree terms with adjacent property owners before oversailing their land. The long horizontal jib is the part of the crane that carries the load. The counter-jib carries a counterweight, usually of concrete blocks, while the jib suspends the load to and from the center of the crane. The crane operator either sits in a cab at the top of the tower or controls the crane by radio remote control from the ground. In the first case the operator's cab is most usually located at the top of the tower attached to the turntable, but can be mounted on the jib, or partway down the tower. The lifting hook is operated by the crane operator using electric motors to manipulate wire rope cables through a system of sheaves. The hook is located on the long horizontal arm to lift the load which also contains its motor. In order to hook and unhook the loads, the operator usually works in conjunction with a signaller (known as a "dogger", "rigger" or "swamper"). They are most often in radio contact, and always use hand signals. The rigger or dogger directs the schedule of lifts for the crane, and is responsible for the safety of the

rigging Rigging comprises the system of ropes, cables and chains, which support and control a sailing ship or sail boat's masts and sails. ''Standing rigging'' is the fixed rigging that supports masts including shrouds and stays. ''Running rigg ...

and loads. Tower cranes can achieve a height under hook of over 100 metres. File:Tower Crane.JPG, Tower crane atop

Mont Blanc Mont Blanc (, ) is a mountain in the Alps, rising above sea level, located right at the Franco-Italian border. It is the highest mountain in Europe outside the Caucasus Mountains, the second-most prominent mountain in Europe (after Mount E ...

File:Tower crane Dubai 2010.jpg, Tower crane cabin File:Кран с маховой стрелой.jpg, Tower crane with "luffing"

jib A jib is a triangular sail that sets ahead of the foremast of a sailing vessel. Its forward corner (tack) is fixed to the bowsprit, to the bows, or to the deck between the bowsprit and the foremost mast. Jibs and spinnakers are the two main ty ...

File:Rotating tower crane.ogv, A tower crane rotates on its axis before lowering the lifting hook. File:Tower crane aerial 01.jpg,

Teleoperation Teleoperation (or remote operation) indicates operation of a system or machine at a distance. It is similar in meaning to the phrase "remote control" but is usually encountered in research, academia and technology. It is most commonly associat ...

tower cranes at a prefabricated framed construction site

= Components

= Tower cranes are used extensively in construction and other industry to hoist and move materials. There are many types of tower cranes. Although they are different in type, the main parts are the same, as follows: * Mast: the main supporting tower of the crane. It is made of steel trussed sections that are connected together during installation. * Slewing unit: the slewing unit sits at the top of the mast. This is the engine that enables the crane to rotate. * Operating cabin: on most tower cranes the operating cabin sits just above the slewing unit. It contains the operating controls, load-movement indicator system (LMI), scale, anemometer, etc. * Jib: the jib, or operating arm, extends horizontally from the crane. A "luffing" jib is able to move up and down; a fixed jib has a rolling trolley car that runs along the underside to move loads horizontally. * Counter jib: holds counterweights, hoist motor, hoist drum and the electronics. (In many older tower crane designs the hoisting devices and electronics were located in the mast foot.) * Hoist winch: the hoist winch assembly consists of the hoist winch (motor, gearbox, hoist drum, hoist rope, and brakes), the hoist motor controller, and supporting components, such as the platform. Many tower cranes have transmissions with two or more speeds. * Hook: the hook is used to connect the material to the crane, suspended from the hoist rope either at the tip (on luffing jib cranes) or routed through the trolley (on hammerhead cranes). * Weights: Large, moveable concrete counterweights are mounted toward the rear of the counterdeck, to compensate for the weight of the goods lifted and keep the center of gravity over the supporting tower.

= Assembly

= A tower crane is usually assembled by a telescopic jib (mobile) crane of greater reach (also see "self-erecting crane" below) and in the case of tower cranes that have risen while constructing very tall skyscrapers, a smaller crane (or

derrick A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its Guy-wire, guys. Most derricks have at least two components, either a guyed mast or self-supporting tower ...

) will often be lifted to the roof of the completed tower to dismantle the tower crane afterwards, which may be more difficult than the installation. Tower cranes can be operated by remote control, removing the need for the crane operator to sit in a cab atop the crane.

= Operation

= Each model and distinctive style of tower crane has a predetermined lifting chart that can be applied to any radii available, depending on its configuration. Similar to a mobile crane, a tower crane may lift an object of far greater mass closer to its center of rotation than at its maximum radius. An operator manipulates several levers and pedals to control each function of the crane.

= Safety

= When a tower crane is used in proximity to buildings, roads, power lines, or other tower cranes, a tower crane anti-collision system is used. This operator support system reduces the risk of a dangerous interaction occurring between a tower crane and another structure. In some countries, such as France, tower crane anti-collision systems are mandatory.

= Self-erecting tower cranes

Generally a type of pedestrian operated tower crane, self-erecting tower cranes are transported as a single unit and can be assembled by a qualified technician without the assistance of a larger mobile crane. They are bottom slewing cranes that stand on outriggers, have no counter jib, have their counterweights and ballast at the base of the mast, cannot climb themselves, have a reduced capacity compared to standard tower cranes, and seldom have an operator's cabin. In some cases, smaller self-erecting tower cranes may have axles permanently fitted to the tower section to make maneuvering the crane onsite easier. Tower cranes can also use a hydraulic-powered jack frame to raise themselves to add new tower sections without any additional other cranes assisting beyond the initial assembly stage. This is how it can grow to nearly any height needed to build the tallest skyscrapers when tied to a building as the building rises. The maximum unsupported height of a tower crane is around 265 ft. For a video of a crane getting taller, see "Crane Building Itself" on YouTube. For another animation of such a crane in use, see "SAS Tower Construction Simulation" on YouTube. Here, the crane is used to erect a scaffold, which, in turn, contains a gantry to lift sections of a bridge spire.

Climbing crane

Climbing crane, at WindEnergy expo, 2018 Many tower cranes are designed to "jump" in stages, effectively lifting themselves to the next level. A specialty example of a climbing crane was introduced by Lagerwey Wind and Enercon to construct a

wind turbine A wind turbine is a device that wind power, converts the kinetic energy of wind into electrical energy. , hundreds of thousands of list of most powerful wind turbines, large turbines, in installations known as wind farms, were generating over ...

tower, where instead of erecting a large crane a smaller climbing crane can raise itself with the structure's construction, lift the generator housing to its top, add the rotor blades, then climb down.

Cargo handling

Rubber-tyred gantry crane

Reach stacker

A reach stacker is a vehicle used for handling intermodal cargo containers in small terminals or medium-sized ports. Reach stackers are able to transport a container short distances very quickly and pile them in various rows depending on its access.

Sidelifter

sidelifter A sidelifter is a specialised vehicle or semi-trailer used to hoist and transport International Organization for Standardization, ISO standard intermodal containers over longer distances. Overview The sidelifter loads and unloads containers via a ...

crane is a road-going

semi-trailer A semi-trailer is a trailer (vehicle), trailer without a front axle. The combination of a semi-trailer and a tractor truck is called a ''semi-trailer truck'' (also known simply as a "semi-trailer", "tractor trailer", or "semi" in the United Sta ...

, able to hoist and transport ISO standard

containers A container is any receptacle or enclosure for holding a product used in storage, packaging, and transportation, including shipping. Things kept inside of a container are protected on several sides by being inside of its structure. The term ...

. Container lift is done with parallel crane-like hoists, which can lift a container from the ground or from a

railway vehicle The term rolling stock in the rail transport industry refers to railway vehicles, including both powered and unpowered vehicles: for example, locomotives, Railroad car#Freight cars, freight and Passenger railroad car, passenger cars (or coaches) ...

=Travel lift

= A

travel lift A travel lift or travelift (also called a boat hoist, boat gantry crane, or boat crane) is a specialised type of crane used for lifting boats out of the water and transporting them around Dock (maritime), docks or marina, marinas. These cranes al ...

(also called a boat gantry crane, or boat crane) is a crane with two rectangular side panels joined by a single spanning beam at the top of one end. The crane is mobile with four groups of steerable wheels, one on each corner. These cranes allow boats with masts or tall super structures to be removed from the water and transported around docks or marinas. Not to be confused mechanical device used for transferring a vessel between two levels of water, which is also called a

boat lift A boat lift, ship lift, or lift lock is a machine for transporting boats between water at two different elevations, and is an alternative to the canal lock. It may be vertically moving, like the Anderton boat lift in England, rotational, li ...

= Straddle carrier

= A Straddle carrier moves and stacks

intermodal container An intermodal container, often called a shipping container, or a freight container, (or simply "container") is a large metal crate designed and built for intermodal freight transport, meaning these containers can be used across different Mode ...

Industrial

Ring

Ring cranes are some of the largest and heaviest land-based cranes ever designed. A ring-shaped track support the main superstructure allowing for extremely heavy loads (up to thousands of tonnes).

Hammerhead

The "hammerhead", or giant

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

, crane is a fixed-

crane consisting of a steel-braced tower on which revolves a large, horizontal, double

; the forward part of this cantilever or

carries the lifting trolley, the jib is extended backwards in order to form a support for the machinery and counterbalancing weight. In addition to the motions of lifting and revolving, there is provided a so-called "racking" motion, by which the lifting trolley, with the load suspended, can be moved in and out along the jib without altering the level of the load. Such horizontal movement of the load is a marked feature of later crane design. These cranes are generally constructed in large sizes and can lift up to 350 tons. The design of ''Hammerkran'' evolved first in Germany around the turn of the 19th century and was adopted and developed for use in

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

shipyard A shipyard, also called a dockyard or boatyard, is a place where ships are shipbuilding, built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Compared to shipyards, which are sometimes m ...

s to support the battleship construction program from 1904 to 1914. The ability of the hammerhead crane to lift heavy weights was useful for installing large pieces of

battleship A battleship is a large, heavily naval armour, armored warship with a main battery consisting of large naval gun, guns, designed to serve as a capital ship. From their advent in the late 1880s, battleships were among the largest and most form ...

s such as

armour plate Military vehicles are commonly armoured (or armored; see spelling differences) to withstand the impact of shrapnel, bullets, shells, rockets, and missiles, protecting the personnel inside from enemy fire. Such vehicles include armoured fightin ...

and

gun A gun is a device that Propulsion, propels a projectile using pressure or explosive force. The projectiles are typically solid, but can also be pressurized liquid (e.g. in water guns or water cannon, cannons), or gas (e.g. light-gas gun). So ...

barrels. Giant cantilever cranes were also installed in naval shipyards in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. The British government also installed a giant cantilever crane at the

Singapore Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...

Naval Base (1938) and later a copy of the crane was installed at Garden Island Naval Dockyard in

Sydney Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

(1951). These cranes provided repair support for the battle fleet operating far from

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

. In the British Empire, the engineering firm Sir William Arrol & Co. was the principal manufacturer of giant cantilever cranes; the company built a total of fourteen. Among the sixty built in the world, few remain; seven in England and Scotland of about fifteen worldwide. Dillingen Kran

The

Titan Clydebank Titan Clydebank, more commonly known as the Titan Crane is a Hammerhead crane, cantilever crane at Clydebank, West Dunbartonshire, Scotland. It was designed to be used in the lifting of heavy equipment, such as engines and boilers, during t ...

is one of the four Scottish cranes on the

River Clyde The River Clyde (, ) is a river that flows into the Firth of Clyde, in the west of Scotland. It is the eighth-longest river in the United Kingdom, and the second longest in Scotland after the River Tay. It runs through the city of Glasgow. Th ...

and preserved as a tourist attraction.

Level luffing

Normally a crane with a hinged jib will tend to have its hook also move up and down as the jib moves (or ''luffs''). A

level luffing crane A level-luffing crane is a crane mechanism where the hook remains at the same level while luffing: moving the jib up and down, so as to move the hook inwards and outwards relative to the base. Usually the description is only applied to those w ...

is a crane of this common design, but with an extra mechanism to keep the hook at the same level when the jib is pivoted in or out.

Overhead

overhead crane An overhead crane, commonly called a bridge crane, is a type of crane found in industrial environments. An overhead crane consists of two parallel rails seated on longitudinal I-beams attached to opposite steel columns by means of brackets. ...

, also known as a bridge crane, is a type of crane where the hook-and-line mechanism runs along a horizontal beam that itself runs along two widely separated rails. Often it is in a long factory building and runs along rails along the building's two long walls. It is similar to a

gantry crane A gantry crane is a Crane (machine), crane built atop a wikt:gantry, gantry, which is a structure used to straddle an object or workspace. They can range from enormous "full" gantry cranes, capable of lifting some of the heaviest loads in the wor ...

. Overhead cranes typically consist of either a single beam or a double beam construction. These can be built using typical steel beams or a more complex box girder type. Pictured on the right is a single bridge box girder crane with the hoist and system operated with a control pendant. Double girder bridge are more typical when needing heavier capacity systems from 10 tons and above. The advantage of the box girder type configuration results in a system that has a lower deadweight yet a stronger overall system integrity. Also included would be a hoist to lift the items, the bridge, which spans the area covered by the crane, and a trolley to move along the bridge. The most common overhead crane use is in the

steel industry Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high elastic modulus, yield strength, fracture strength and low raw material cost, steel is one of the ...

. At every step of the manufacturing process, until it leaves a factory as a finished product,

is handled by an overhead crane. Raw materials are poured into a furnace by crane, hot steel is stored for cooling by an overhead crane, the finished coils are lifted and loaded onto

s and

train A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...

s by overhead crane, and the fabricator or stamper uses an overhead crane to handle the steel in his factory. The

automobile A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...

industry uses overhead cranes for handling of raw materials. Smaller

workstation A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...

cranes handle lighter loads in a work-area, such as CNC mill or saw. Almost all paper mills use bridge cranes for regular maintenance requiring removal of heavy press rolls and other equipment. The bridge cranes are used in the initial construction of paper machines because they facilitate installation of the heavy cast iron paper drying drums and other massive equipment, some weighing as much as 70 tons. In many instances the cost of a bridge crane can be largely offset with savings from not renting mobile cranes in the construction of a facility that uses a lot of heavy process equipment. This

electric overhead traveling crane Electric overhead traveling cranes or EOT cranes are a common type of overhead crane, also called bridge cranes. They consist of parallel runways, much akin to rails of a railroad, with a traveling bridge spanning the gap. EOT cranes are specifica ...

is most common type of overhead crane, found in many factories. These cranes are electrically operated by a control pendant, radio/IR remote pendant, or from an operator cabin attached to the crane.

Gantry

A gantry crane has a hoist in a fixed machinery house or on a trolley that runs horizontally along rails, usually fitted on a single beam (mono-girder) or two beams (twin-girder). The crane frame is supported on a gantry system with equalized beams and wheels that run on the gantry rail, usually perpendicular to the trolley travel direction. These cranes come in all sizes, and some can move very heavy loads, particularly the extremely large examples used in shipyards or industrial installations. A special version is the

container crane A container crane (also container handling gantry crane or ship-to-shore crane) is a type of large dock (maritime), dockside gantry crane found at container terminals for loading and unloading intermodal containers from container ships. Containe ...

(or "Portainer" crane, named by the first manufacturer), designed for loading and unloading ship-borne containers at a port. Most

s are of this type.

Jib

A jib crane is a type of crane - not to be confused with a crane rigged with a jib to extend its main boom - where a horizontal member (''jib'' or ''boom''), supporting a moveable hoist, is fixed to a wall or to a floor-mounted pillar. Jib cranes are used in industrial premises and on military vehicles. The jib may swing through an arc, to give additional lateral movement, or be fixed. Similar cranes, often known simply as hoists, were fitted on the top floor of warehouse buildings to enable goods to be lifted to all floors.

Bulk-handling

Bulk-handling cranes are designed from the outset to carry a shell grab or bucket, rather than using a hook and a sling. They are used for bulk cargoes, such as coal, minerals, scrap metal etc.

Stacker

A crane with a

type mechanism used in automated (computer-controlled)

warehouse A warehouse is a building for storing goods. Warehouses are used by manufacturers, importers, exporters, wholesalers, transport businesses, customs, etc. They are usually large plain buildings in industrial parks on the rural–urban fringe, out ...

s (known as an

automated storage and retrieval system An automated storage and retrieval system (ASRS or AS/RS) consists of a variety of computer-controlled systems for automatically placing and retrieving loads from defined storage locations. Automated storage and retrieval systems (AS/RS) are ty ...

(AS/RS)). The crane moves on a track in an aisle of the warehouse. The fork can be raised or lowered to any of the levels of a storage rack and can be extended into the rack to store and retrieve the product. The product can in some cases be as large as an

. Stacker cranes are often used in the large freezer warehouses of frozen food manufacturers. This automation avoids requiring forklift drivers to work in below-freezing temperatures every day.

Marine

Floating

Floating cranes are used mainly in

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

building and

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...

construction, but they are also used for occasional loading and unloading of especially heavy or awkward loads on and off ships. Some floating cranes are mounted on pontoons, others are specialized crane

barge A barge is typically a flat-bottomed boat, flat-bottomed vessel which does not have its own means of mechanical propulsion. Original use was on inland waterways, while modern use is on both inland and ocean, marine water environments. The firs ...

s with a lifting capacity exceeding and have been used to transport entire bridge sections. Floating cranes have also been used to salvage sunken

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

s. Crane vessels are often used in

offshore construction Offshore construction is the installation of structures and facilities in a marine environment, usually for the production and transmission of electricity, oil, gas and other resources. It is also called maritime engineering. Construction a ...

. The largest revolving cranes can be found on SSCV ''Sleipnir'', which has two cranes with a capacity of each. For 50 years, the largest such crane was " Herman the German" at the Long Beach Naval Shipyard, one of three constructed by

Nazi Germany Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German Reich, German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a Totalit ...

and captured in the war. The crane was sold to the

Panama Canal The Panama Canal () is an artificial waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a Channel (geography), conduit for maritime trade between th ...

in 1996 where it is now known as ''Titan''.

Deck

Deck cranes, also known as shipboard or cargo cranes, are located on ships and boats, used for cargo operations where no shore unloading facilities are available, raising and lowering loads (such as shellfish dredges and fish nets) into the water, and small boat unloading and retrieval. Most are diesel-hydraulic or electric-hydraulic, supporting an increasingly automated control interface.

Other types

Railroad

A railroad crane has flanged wheels for use on railroads. The simplest form is a crane mounted on a

flatcar A flatcar (US) (also flat car, or flatbed) is a piece of rolling stock that consists of an open, flat deck mounted on trucks (US) or bogies (UK) at each end. Occasionally, flat cars designed to carry extra heavy or extra large loads are mounted ...

. More capable devices are purpose-built. Different types of crane are used for maintenance work, recovery operations and freight loading in goods yards and scrap handling facilities.

Aerial

CH-54-Skycrane-delivers-dozer-vietnam-oct-1966

Aerial crane An aerial crane or flying crane is a helicopter used to lift heavy or awkward loads. As aerial cranes, helicopters carry loads connected to long cables or slings in order to place heavy equipment when other methods are not available or economical ...

s or "sky cranes" usually are

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

s designed to lift large loads. Helicopters are able to travel to and lift in areas that are difficult to reach by conventional cranes. Helicopter cranes are most commonly used to lift loads onto shopping centers and high-rise buildings. They can lift anything within their lifting capacity, such as air conditioning units, cars, boats, swimming pools, etc. They also perform disaster relief after natural disasters for clean-up, and during wild-fires they are able to carry huge buckets of water to extinguish fires. Some aerial cranes, mostly concepts, have also used lighter-than air aircraft, such as

airship An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying powered aircraft, under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the ...

Efficiency increase of cranes

Lifetime of existing cranes made of welded metal structures can often be extended for many years by after treatment of welds. During development of cranes, load level (lifting load) can be significantly increased by taking into account the IIW recommendations, leading in most cases to an increase of the permissible lifting load and thus to an efficiency increase.

Similar machines

The generally accepted definition of a crane is a machine for lifting and moving heavy objects by means of ropes or cables suspended from a movable arm. As such, a lifting machine that does not use cables, or else provides only vertical and not horizontal movement, cannot strictly be called a 'crane'. Types of crane-like lifting machine include: *

gin pole A gin pole is a pivoting guyed_mast, mast supported by one or more guy-wires that uses a pulley or block and tackle mounted on its upper end to lift loads. The lower end is braced or set in a shallow hole and positioned so the upper end lie ...

Block and tackle A block and tackle or only tackle is a system of two or more pulleys with a rope or cable threaded between them, used to provide tension and lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is ...

Capstan (nautical) A capstan is a vertical-axled rotating machine developed for use on sailing ships to multiply the pulling force of sailors when hauling ropes, Nautical cable, cables, and hawsers. The principle is similar to that of the windlass, which has a hor ...

Hoist (device) A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting ...

Winch A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension (physics), tension of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form, it consists of a Bobb ...

Windlass The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound arou ...

* Cherry picker More technically advanced types of such lifting machines are often known as "cranes", regardless of the official definition of the term.

Special examples

Finnieston Crane The Finnieston Crane or Stobcross Crane is a disused Crane (machine)#Hammerhead, giant cantilever crane in the centre of Glasgow, Scotland. It is no longer operational, but is retained as a symbol of the city's engineering heritage. The crane w ...

, a.k.a. the ''Stobcross Crane'' ** Category A-listed example of a "hammerhead" (cantilever) crane in

Glasgow Glasgow is the Cities of Scotland, most populous city in Scotland, located on the banks of the River Clyde in Strathclyde, west central Scotland. It is the List of cities in the United Kingdom, third-most-populous city in the United Kingdom ...

's former docks, built by the William Arrol company. ** tall, capacity, built 1926 *

Taisun Taisun (; Mount Tai, Taishan) is a gantry crane with a Lifting equipment#Working load limit, safe working load of 20,000 metric tons (22,046 short tons). Taisun was designed by DHHI (Dalian Huarui Heavy Industry) and built for the installation of ...

** double bridge crane at

Yantai Yantai, formerly known as Chefoo, is a coastal prefecture-level city on the Shandong Peninsula in northeastern Shandong province of the People's Republic of China. Lying on the southern coast of the Bohai Strait, Yantai borders Qingdao ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. ** capacity, World Record Holder ** tall, span, lift-height * Kockums Crane ** shipyard crane formerly at

Kockums Saab Kockums AB is a shipyard headquartered in Malmö, Sweden, owned by the Swedish defence company Saab AB. Saab Kockums AB is further operational in Muskö, Docksta, and Karlskrona. While having a history of civil vessel construction, Kocku ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. ** tall, capacity, since moved to

Ulsan Ulsan (; ), officially the Ulsan Metropolitan City, is South Korea's seventh-largest metropolitan city and the eighth-largest city overall, with a population of over 1.1 million inhabitants. It is located in the south-east of the country, neighbo ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

Samson and Goliath (cranes) Samson and Goliath are the twin shipbuilding gantry cranes at Queen's Island, Belfast, Northern Ireland. The cranes, which were named after the Biblical figures Samson and Goliath, dominate the Belfast skyline and are landmark structures. His ...

** two

s at the

Harland & Wolff Harland & Wolff Holdings plc is a British shipbuilding and Metal fabrication, fabrication company headquartered in London with sites in Belfast, Arnish yard, Arnish, Appledore, Torridge, Appledore and Methil. It specialises in ship repair, ship ...

shipyard in

Belfast Belfast (, , , ; from ) is the capital city and principal port of Northern Ireland, standing on the banks of the River Lagan and connected to the open sea through Belfast Lough and the North Channel (Great Britain and Ireland), North Channel ...

built by

Krupp Friedrich Krupp AG Hoesch-Krupp (formerly Fried. Krupp AG and Friedrich Krupp GmbH), trade name, trading as Krupp, was the largest company in Europe at the beginning of the 20th century as well as Germany's premier weapons manufacturer dur ...

** ''Goliath'' is tall, ''Samson'' is ** span , lift-height , capacity each, combined * Breakwater Crane Railway ** self-propelled steam crane that formerly ran the length of the breakwater at

Douglas Douglas may refer to: People * Douglas (given name) * Douglas (surname) Animals * Douglas (parrot), macaw that starred as the parrot ''Rosalinda'' in Pippi Longstocking * Douglas the camel, a camel in the Confederate Army in the American Civil ...

. ** ran on gauge track, the broadest in the British Isles *

Liebherr Liebherr () is a German-Swiss multinational corporation, multinational equipment manufacturer based in Bulle, Switzerland, with its main production facilities and origins in Germany. Liebherr consists of over 130 companies organized into 11 divi ...

TCC 78000 ** Heavy-duty gantry crane used for heavy lifting operated in

Rostock Rostock (; Polabian language, Polabian: ''Roztoc''), officially the Hanseatic and University City of Rostock (), is the largest city in the German States of Germany, state of Mecklenburg-Vorpommern and lies in the Mecklenburgian part of the sta ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. ** capacity, lift-height

Crane operators

Crane operators are

skilled worker A skilled worker is any worker who has special skill, training, or knowledge which they can then apply to their work. A skilled worker may have learned their skills through work experience, on-the-job training, an apprenticeship program or f ...

s and

heavy equipment operator A heavy equipment operator operates heavy equipment used in engineering and construction projects. Typically only skilled workers may operate heavy equipment, and there is specialized training for learning to use heavy equipment. Operator train ...

s. Key skills that are needed for a crane operator include: *An understanding of how to use and maintain machines and tools *Good team working skills *Attention to details *Good spatial awareness. *Patience and the ability to stay calm in stressful situations

Terminology

The ISO 4306 series of specifications establish the vocabulary for cranes: * Part 1: General * Part 2: Mobile cranes * Part 3: Tower cranes * Part 4: Jib cranes * Part 5: Bridge and gantry cranes * Luffing *

Slewing Slewing is the rotation of an object around an axis, usually the z axis. An example is a radar scanning 360 degrees by slewing around the z axis. This is also common terminology in astronomy. The process of rotating a telescope to observe a diffe ...

* Hoisting

References

Sources

History of cranes * * * * * * * {{DEFAULTSORT:Crane (Machine) Construction equipment Heavy equipment Lifting equipment Vertical transport devices Ancient Egyptian technology Ancient Greek technology Ancient inventions Articles containing video clips

Etymology

History

Ancient Near East

Ancient Greece

Roman Empire

Middle Ages

Structure and placement

Mechanics and operation

Harbour usage

Early modern age

Industrial revolution

Mechanical principles

Stability

Dynamic Lift Factor

Overview

Formulas

Types

Construction

Truck-mounted

Loader

Telescopic

Rough-terrain

All-terrain

Crawler

Pick-and-carry

Carry-deck

Telescopic handler

Block-setting crane

Tower

= Components

= Assembly

= Operation

= Safety

= Self-erecting tower cranes

Climbing crane

Cargo handling

Rubber-tyred gantry crane

Reach stacker

Sidelifter

=Travel lift

= Straddle carrier

Industrial

Ring

Hammerhead

Level luffing

Overhead

Gantry

Jib

Bulk-handling

Stacker

Marine

Floating

Deck

Other types

Railroad

Aerial

Efficiency increase of cranes

Similar machines

Special examples

Crane operators

Terminology

See also

References

Sources