![3U2A6305](https://upload.wikimedia.org/wikipedia/commons/8/80/3U2A6305.jpg)
A crane is a type of
machine
A machine is a physical system using Power (physics), power to apply Force, forces and control Motion, movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to na ...
, generally equipped with a
hoist rope,
wire rope
Steel wire rope (right hand lang lay)
Wire rope is several strands of metal wire twisted into a helix forming a composite
''rope'', in a pattern known as ''laid rope''. Larger diameter wire rope consists of multiple strands of such laid rope in a ...
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 c ...
s, and
sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy objects and transporting them to other places. The device uses one or more
simple machine
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refer ...
s to create
mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in transportation for the loading and unloading of freight, in
construction
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and com ...
for the movement of materials, and in manufacturing for the assembling of
heavy equipment
Heavy equipment or heavy machinery refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. ''Heavy equipment'' usually comprises five e ...
.
The first known crane machine was the
shaduf
A shadoof or shaduf (from the Arabic language, Arabic word , ''šādūf'') is an irrigation tool. It is highly efficient, and has been known since 3000 BCE.
Names
It is also called a lift, well pole, well sweep, or simply a sweep in the US.Kni ...
, a water-lifting device that was invented in ancient
Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the F ...
(modern Iraq) and then appeared in
ancient Egyptian technology. Construction cranes later appeared in
ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...
, 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 ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
, 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 that lasted from AD 1000 to 1300. The High Middle Ages were preceded by the Early Middle Ages and were followed by the Late Middle Ages, which ended ...
, 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 more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ...
,
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) 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, right in f ...
and
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
took over with the coming of the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
.
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 milling (grinding), rolling, or hammering. Such processes are needed in the production of ...
s and
windmills 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 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. This pushing force can be trans ...
s, the earliest
steam crane 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 combus ...
s or
electric motor
An electric motor is an Electric machine, electrical 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 Electromagneti ...
s and
hydraulic 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
{{about, , the mnemonic OIL RIG, Redox
An oil rig is any kind of apparatus constructed for oil drilling.
Kinds of oil rig include:
* Drilling rig, an apparatus for on-land oil drilling
* Drillship, a floating apparatus for offshore oil drilling
* ...
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 Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
, cf.
grc, γερανός, French ''grue''.
History
Ancient Near East
The first type of crane machine was the
shadouf
A shadoof or shaduf (from the Arabic word , ''šādūf'') is an irrigation tool. It is highly efficient, and has been known since 3000 BCE.
Names
It is also called a lift, well pole, well sweep, or simply a sweep in the US.Knight, Edward Henry ...
, which had a lever mechanism and was used to lift water for
irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...
.
It was invented in
Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the F ...
(modern Iraq) circa 3000 BC.
The shadouf subsequently appeared in
ancient Egyptian technology circa 2000 BC.
Ancient Greece
![Trispastos scheme](https://upload.wikimedia.org/wikipedia/commons/a/ab/Trispastos_scheme.svg)
A crane for lifting heavy loads was developed by the
Ancient Greeks
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cultu ...
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 of a rope or wire rope (also called "cable" or "wire cable").
In its simplest form, it consists of a spool (or drum) attache ...
and
pulley
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. In the case of a pulley supported by a frame or shell that ...
hoist soon led to a widespread replacement of
ramps
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six clas ...
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 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,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...
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'' (, ; grc-gre, πόλις, ), plural ''poleis'' (, , ), literally means "city" in Greek. In Ancient Greece, it originally referred to an administrative and religious city center, as distinct from the rest of the city. Later, it also ...
over the more labour-intensive ramp which had been the norm in the autocratic societies of
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...
or
Assyria
Assyria (Neo-Assyrian cuneiform: , romanized: ''māt Aššur''; syc, ܐܬܘܪ, ʾāthor) was a major ancient Mesopotamian civilization which existed as a city-state at times controlling regional territories in the indigenous lands of the A ...
.
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 (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...
(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
![Roemerkran](https://upload.wikimedia.org/wikipedia/commons/c/ca/Roemerkran.jpg)
The heyday of the crane in ancient times came during the
Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
, when construction activity soared and buildings reached enormous dimensions. The Romans adopted the Greek crane and developed it further. We are relatively well informed about their lifting techniques, thanks to rather lengthy accounts by the engineers
Vitruvius
Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled ''De architectura''. He originated the idea that all buildings should have three attribute ...
(''De Architectura'' 10.2, 1–10) and
Heron of Alexandria (''Mechanica'' 3.2–5). There are also two surviving reliefs of Roman
treadwheel crane
A treadwheel crane (Latin: ''magna rota'') 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 ...
s, with the
Haterii tombstone from the late first century AD being particularly detailed.
The simplest Roman crane, the ''trispastos'', consisted of a single-beam jib, a
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 of a rope or wire rope (also called "cable" or "wire cable").
In its simplest form, it consists of a spool (or drum) attache ...
, a
rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly ...
, and a block containing three pulleys. Having thus a
mechanical advantage 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 Egyptian
pyramids
A pyramid (from el, πυραμίς ') is a structure whose outer surfaces are triangular and converge to a single step at the top, making the shape roughly a pyramid in the geometric sense. The base of a pyramid can be trilateral, quadrilate ...
, 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 (; ar, بَعْلَبَكّ, Baʿlabakk, Syriac-Aramaic: ܒܥܠܒܟ) 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 Greek and Roman ...
, for instance, the
architrave
In classical architecture, an architrave (; from it, architrave "chief beam", also called an epistyle; from Greek ἐπίστυλον ''epistylon'' "door frame") is the lintel or beam that rests on the capitals of columns.
The term can ...
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 that crowns a building or furniture element—for example, the cornice over a door or window, around the top edge of a ...
block even over 100 tons, all of them raised to a height of about .
In
Rome
, established_title = Founded
, established_date = 753 BC
, founder = King Romulus (legendary)
, image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg
, map_caption ...
, 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, 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 Anglicisation, anglicised as Ammian) (born , died 400) was a Roman soldier and historian who wrote the penultimate major historical account surviving from Ancient history, antiquity (preceding Procopius). His w ...
(17.4.15) in connection with the lifting of the
Lateranense obelisk in the
Circus Maximus (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.
Middle Ages
During the
High Middle Ages
The High Middle Ages, or High Medieval Period, was the periodization, period of European history that lasted from AD 1000 to 1300. The High Middle Ages were preceded by the Early Middle Ages and were followed by the Late Middle Ages, which ended ...
, 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
The Western Roman Empire comprised the western provinces of the Roman Empire at any time during which they were administered by a separate independent Imperial court; in particular, this term is used in historiography to describe the period fr ...
. 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 and a List of municipalities of the Netherlands, municipality of the Netherlands, capital and most populous city of the Provinces of the Netherlands, pro ...
in 1244,
Antwerp
Antwerp (; nl, Antwerpen ; french: Anvers ; es, Amberes) is the largest city in Belgium by area at and the capital of Antwerp Province in the Flemish Region. With a population of 520,504, in 1263,
Bruges
Bruges ( , nl, Brugge ) is the capital and largest City status in Belgium, city of the Provinces of Belgium, province of West Flanders in the Flemish Region of Belgium, in the northwest of the country, and the sixth-largest city of the countr ...
in 1288 and
Hamburg
(male), (female) en, Hamburger(s),
Hamburgian(s)
, timezone1 = Central (CET)
, utc_offset1 = +1
, timezone1_DST = Central (CEST)
, utc_offset1_DST = +2
, postal ...
in 1291,
while in England the treadwheel is not recorded before 1331.
![Tretkran (Bruegel)](https://upload.wikimedia.org/wikipedia/commons/3/3d/Tretkran_%28Bruegel%29.jpg)
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 created in Europe between the mid-12th century and the beginning of the 16th century. The cathedrals are notable particularly for their great height and their extensive use of stained glass ...
. 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 vehicle, usually with just one wheel, designed to be pushed and guided by a single person using two handles at the rear, or by a sail to push the ancient wheelbarrow by wind. The term "wheelbarrow" is mad ...
s did not completely replace more labor-intensive methods like
ladder
A ladder is a vertical or inclined set of rungs or steps used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such a ...
s,
hods and handbarrows. 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 l ...
s,
cranks and by the 15th century also by windlasses shaped like a
ship's wheel. To smooth out irregularities of impulse and get over 'dead-spots' in the lifting process
flywheel
A flywheel is a mechanical device which 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, ass ...
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
Vitruvius
Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled ''De architectura''. He originated the idea that all buildings should have three attribute ...
' ''
De architectura
(''On architecture'', published as ''Ten Books on Architecture'') is a treatise on architecture written by the Roman architect and military engineer Marcus Vitruvius Pollio and dedicated to his patron, the emperor Caesar Augustus, as a guide f ...
'' 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 energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets ...
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](https://upload.wikimedia.org/wikipedia/commons/d/de/Reconstruction_of_the_temple_of_Jerusalem.jpg)
Contrary to a popularly held belief, cranes on medieval building sites were neither placed on the extremely lightweight
scaffolding 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
![Trier Germany Alter Krahnen](https://upload.wikimedia.org/wikipedia/commons/d/de/Trier_Germany_Alter_Krahnen.jpg)
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 front loader, a jacking device, or an erect crane. A pallet is the structural foundat ...
s,
baskets, 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 staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...
s.
It is noteworthy that medieval cranes rarely featured
ratchets or
brake
A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction.
Background ...
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-saws,
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 of a rope or wire rope (also called "cable" or "wire cable").
In its simplest form, it consists of a spool (or drum) attache ...
es and
yards.
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 ( , also ; ; csb, Gduńsk;Stefan Ramułt, ''Słownik języka pomorskiego, czyli kaszubskiego'', Kraków 1893, Gdańsk 2003, ISBN 83-87408-64-6. , Johann Georg Theodor Grässe, ''Orbis latinus oder Verzeichniss der lateinischen Benen ...
,
Cologne
Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western States of Germany, state of North Rhine-Westphalia (NRW) and the List of cities in Germany by population, fourth-most populous city of Germany with 1.1 m ...
and
Bremen
Bremen (Low German also: ''Breem'' or ''Bräm''), officially the City Municipality of Bremen (german: Stadtgemeinde Bremen, ), is the capital of the German state Free Hanseatic City of Bremen (''Freie Hansestadt Bremen''), a two-city-state consis ...
.
Beside these stationary cranes,
floating cranes
Floating may refer to:
* a type of dental work performed on horse teeth
* use of an isolation tank
* the guitar-playing technique where chords are sustained rather than scratched
* ''Floating'' (play), by Hugh Hughes
* Floating (psychological phe ...
, which could be flexibly deployed in the whole port basin came into use by the 14th century.
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 architect of the late Renaissance, born in today's Ticino. He worked primarily in Italy, at Rome and Naples.
Biography
He was born at Melide, a village on the Lake Lugano, at that time joint p ...
in 1586 to relocate the 361 t heavy
Vatican obelisk 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 Vatican obelisk 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 (german: Kölner Dom, officially ', English: Cathedral Church of Saint Peter) is a Catholic cathedral in Cologne, North Rhine-Westphalia. It is the seat of the Archbishop of Cologne and of the administration of the Archdiocese of ...
File:Fireplace crane02.jpg, Fireplace crane
Industrial revolution
![William george armstrong](https://upload.wikimedia.org/wikipedia/commons/4/41/William_george_armstrong.jpg)
With the onset of the
Industrial Revolution
The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
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
A hydraulic jigger is a hydraulically-powered mechanical winch.
From the mid-19th century, hydraulic power network, hydraulic power became available throughout the increasingly modern dockyards and warehouses. This was generated centrally and dist ...
. 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. 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. 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 Elswick may refer to:
*Elswick, Lancashire, England
*Elswick, Newcastle upon Tyne, Tyne and Wear, England
*Elswick, Saskatchewan, a ghost town in Canada
*Elswick (automobile), an English automobile
*Elswick Ordnance Company
The Elswick Ordnance ...
at
Newcastle, 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 and b ...
for cranes and bridges in 1847. His company soon received orders for hydraulic cranes from Edinburgh and Northern Railways and from
Liverpool Docks, as well as for hydraulic machinery for dock gates in
Grimsby
Grimsby or Great Grimsby is a port town and the administrative centre of North East Lincolnshire, Lincolnshire, England. Grimsby adjoins the town of Cleethorpes directly to the south-east forming a conurbation. Grimsby is north-east of Linco ...
. 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 hydraulic fluid is held under pressure that is applied by an external source of mechanical energy. The external source can be an engine, a spring, a raised weight, ...
. 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 Ouse and Trent. From there to the North Sea, it forms part of the boundary between the ...
, 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
"Fatherland and Honour"
, patron =
, colors =
, colors_label =
, march = ( is the return of soldiers to their barrack, or sailors to their ship after a ...
in 1883 and in use until the mid-1950s, is still standing in
Venice
Venice ( ; it, Venezia ; vec, Venesia or ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 small islands that are separated by canals and linked by over 400 ...
, 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 rupture.
File:El movimiento de una grua.ogg, Crane movements
File:Shipyard Ishibras Ishikawajima Sermetal.JPG, Broken crane in Sermetal Shipyard, former Ishikawajima do Brasil – Rio de Janeiro
Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...
. The cause of the accident was a lack of maintenance and misuse of the equipment.
File:Automated Crane With Utensils.jpg, Cranes can mount many different utensils, depending on load (left). Cranes can be remote-controlled from the ground, allowing much more precise control, but without the view that a position atop the crane provides (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.
Types
Mobile
![Crane vehicle in Sörnäinen](https://upload.wikimedia.org/wikipedia/commons/6/62/Crane_vehicle_in_S%C3%B6rn%C3%A4inen.jpg)
There are four principal types of mobile cranes: truck mounted, rough-terrain, crawler, and floating.
Truck-mounted
The most basic
truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...
-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.
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 ...
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, Liebherr truck mounted crane building a bridge
File:Truck crane.jpg, A Grove truck-mounted crane in road travel configuration
File:Crane Truck Model.png, A model of a crane carried by a flatbed truck
Rough terrain
![Omega 18](https://upload.wikimedia.org/wikipedia/commons/5/55/Omega_18.jpg)
A rough terrain crane has a
boom
Boom may refer to:
Objects
* Boom (containment), a temporary floating barrier used to contain an oil spill
* Boom (navigational barrier), an obstacle used to control or block marine navigation
* Boom (sailing), a sailboat part
* Boom (windsurfi ...
mounted on an
undercarriage
Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:
*The landing gear of an aircraft.
*The ch ...
atop four rubber tires that is designed for
off-road
Off-roading is the activity of driving or riding in a vehicle on unpaved surfaces such as sand, gravel, riverbeds, mud, snow, rocks, and other natural terrain. Types of off-roading range in intensity, from leisure drives with unmodified vehicl ...
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.
Crawler
![Big Tracked Construction Crane Auckland](https://upload.wikimedia.org/wikipedia/commons/9/9e/Big_Tracked_Construction_Crane_Auckland.jpg)
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 .
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.
Floating
![SSCVThialf](https://upload.wikimedia.org/wikipedia/commons/4/40/SSCVThialf.jpg)
Floating cranes are used mainly in
bridge
A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...
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 Ham ...
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
Barge nowadays generally refers to a flat-bottomed inland waterway vessel which does not have its own means of mechanical propulsion. The first modern barges were pulled by tugs, but nowadays most are pushed by pusher boats, or other vessels ...
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 that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...
s.
Crane vessels are often used in
offshore construction.
The largest revolving cranes can be found on
SSCV ''Thialf'', 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
The Long Beach Naval Shipyard (Long Beach NSY or LBNSY), which closed in 1997, was located on Terminal Island between the city of Long Beach and the San Pedro district of Los Angeles, approximately 23 miles south of the Los Angeles International ...
, one of three constructed by
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
and captured in the war. The crane was sold to the
Panama Canal
The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a conduit ...
in 1996 where it is now known as ''Titan''.
Other types
=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.
=All terrain
=
![GMK3050 All Terrain Crane](https://upload.wikimedia.org/wikipedia/commons/5/5e/GMK3050_All_Terrain_Crane.jpg)
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 .
=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.
=Sidelifter
=
![Bundesarchiv Bild 183-K0315-0001-026, Leipzig, Frühjahrsmesse, Freigelände, Sattelauflieger, Container](https://upload.wikimedia.org/wikipedia/commons/3/36/Bundesarchiv_Bild_183-K0315-0001-026%2C_Leipzig%2C_Fr%C3%BChjahrsmesse%2C_Freigel%C3%A4nde%2C_Sattelauflieger%2C_Container.jpg)
A
sidelifter crane is a road-going
truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...
or
semi-trailer, 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, freight and passenger cars (or coaches), and non-revenue cars. Passenger vehicles can be ...
.
=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
=
![Mobile container crane](https://upload.wikimedia.org/wikipedia/commons/e/e0/Mobile_container_crane.jpeg)
Telescopic handlers are
forklift
A forklift (also called 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 century by various c ...
-like trucks that have 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.
=Harbour
=
![Kotka shipyard August 1968 01](https://upload.wikimedia.org/wikipedia/commons/6/64/Kotka_shipyard_August_1968_01.jpg)
Dry bulk or container cranes usually in the bay areas or inland water ways.
=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 docks or marinas. These cranes allow boats with masts or t ...
(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.
=Railroad
=
![Spr64](https://upload.wikimedia.org/wikipedia/commons/0/00/Spr64.jpg)
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 a pair of trucks (US) or bogies (UK), one at each end containing four or six wheels. Occasionally, flat cars designed to carry ...
. 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
=
Aerial cranes or "sky cranes" usually are
helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
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 or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air.
In early ...
s.
= Climbing crane
=
Lagerwey climbing crane, at WindEnergy expo, 2018
Instead of setting up a large crane to construct a
wind turbine
A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. ...
tower, a smaller climbing crane can help build the tower, climb with it to the top, lift the generator housing to its top, add the rotor blades, then climb down. This has been introduced by Lagerwey Wind and
Enercon.
= Straddle carrier
=
A Straddle carrier moves and stacks
intermodal container
An intermodal container, often called a shipping container, is a large standardized shipping container, designed and built for intermodal freight transport, meaning these containers can be used across different Mode of transport, modes of trans ...
s.
Fixed
Exchanging mobility for the ability to carry greater loads and reach greater heights due to increased stability, these types of cranes are characterised by the fact that their main structure does not move during the period of use. However, many can still be assembled and disassembled. The structures basically are fixed in one place.
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).
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.
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 a sailing ship or sail boat's masts—''standing rigging'', including shrouds and stays—and which adjust the position of the vessel's sails and spars to which they are ...
and loads.
Tower cranes can achieve a height under hook of over 100 metres.
File:Tower Crane.JPG, Tower crane atop Mont Blanc
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 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 types of headsails ...
File:Rotating tower crane.ogv, A tower crane rotates on its axis before lowering the lifting hook.
= 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 that runs along the underside to move goods horizontally.
* Counter jib: holds counterweights, hoist motor, hoist drum and the electronics.
* 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 (or hooks) is used to connect the material to the crane. It is suspended from the hoist rope either at the tip, for luffing jib cranes, or in the hoist rope belly underneath the trolley for 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) 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
![Origami Crane](https://upload.wikimedia.org/wikipedia/commons/f/fb/Origami_Crane.JPG)
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.
Telescopic
![Telescopic crane, SouthGate, Bath](https://upload.wikimedia.org/wikipedia/commons/b/b1/Telescopic_crane%2C_SouthGate%2C_Bath.jpg)
A telescopic crane has a boom that consists of a number of tubes fitted one inside the other. A
hydraulic cylinder 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.
Hammerhead
![Wfm crane north rotunda](https://upload.wikimedia.org/wikipedia/commons/c/ce/Wfm_crane_north_rotunda.jpg)
The "hammerhead", or giant
cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only 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 canti ...
, crane is a fixed-
jib
A jib is a triangular sail that sets ahead of the foremast of a sailing vessel. Its 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 types of headsails ...
crane consisting of a steel-braced tower on which revolves a large, horizontal, double
cantilever
A cantilever is a rigid structural element that extends horizontally and is supported at only 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 canti ...
; the forward part of this cantilever or
jib
A jib is a triangular sail that sets ahead of the foremast of a sailing vessel. Its 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 types of headsails ...
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 weigh 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 shipyard
A shipyard, also called a dockyard or boatyard, is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance a ...
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 armored warship with a main battery consisting of large caliber guns. It dominated naval warfare in the late 19th and early 20th centuries.
The term ''battleship'' came into use in the late 1880s to describe a type of ...
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 fight ...
and
gun
A gun is a ranged weapon designed to use a shooting tube (gun barrel) to launch projectiles. The projectiles are typically solid, but can also be pressurized liquid (e.g. in water guns/cannons, spray guns for painting or pressure washing, pr ...
barrels. Giant cantilever cranes were also installed in naval shipyards in
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
and in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
. The British government also installed a giant cantilever crane at the
Singapore
Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...
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 state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...
(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 northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
.
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.
The
Titan Clydebank
Titan Clydebank, more commonly known as the Titan Crane is a 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 the fitting-out of ...
is one of the four Scottish cranes on the
River Clyde
The River Clyde ( gd, Abhainn Chluaidh, , sco, Clyde Watter, or ) is a river that flows into the Firth of Clyde in Scotland. It is the ninth-longest river in the United Kingdom, and the third-longest in Scotland. It runs through the major cit ...
and preserved as a tourist attraction.
Level luffing
![Dillingen Kran](https://upload.wikimedia.org/wikipedia/commons/d/d6/Dillingen_Kran.jpg)
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 is a crane of this common design, but with an extra mechanism to keep the hook at the same level when luffing.
Overhead
![DCC38974rvancopp](https://upload.wikimedia.org/wikipedia/commons/9/9c/DCC38974rvancopp.jpg)
An
overhead crane, 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. 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. At every step of the manufacturing process, until it leaves a factory as a finished product,
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
is handled by an overhead crane. Raw materials are poured into a
furnace
A furnace is a structure in which heat is produced with the help of combustion.
Furnace may also refer to:
Appliances Buildings
* Furnace (central heating): a furnace , or a heater or boiler , used to generate heat for buildings
* Boiler, used t ...
by crane, hot steel is stored for cooling by an overhead crane, the finished coils are lifted and loaded onto
truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...
s and
train
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
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 automobile is a motor vehicle with Wheel, wheels. Most definitions of ''cars'' say that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, pe ...
industry uses overhead cranes for handling of raw materials. Smaller
workstation
A workstation is a special computer designed for technical or 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 systems. The term ''workstat ...
cranes handle lighter loads in a work-area, such as
CNC
Numerical control (also computer numerical control, and commonly called CNC) is the automated control of machining tools (such as drills, lathes, mills, grinders, routers and 3D printers) by means of a computer. A CNC machine processes a ...
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.
Electric overhead traveling crane
![Submarí Ictineu 3 col·locat sota un pont grua](https://upload.wikimedia.org/wikipedia/commons/4/46/Submar%C3%AD_Ictineu_3_col%C2%B7locat_sota_un_pont_grua.JPG)
This 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
![Maschine zum Übersetzen der Diligencen auf Eisenbahnwaggons](https://upload.wikimedia.org/wikipedia/commons/4/45/Maschine_zum_%C3%9Cbersetzen_der_Diligencen_auf_Eisenbahnwaggons.JPG)
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 dockside gantry crane found at container terminals for loading and unloading intermodal containers from container ships.
Container cranes consis ...
(or "Portainer" crane, named by the first manufacturer), designed for loading and unloading ship-borne containers at a port.
Most
container crane
A container crane (also container handling gantry crane or ship-to-shore crane) is a type of large dockside gantry crane found at container terminals for loading and unloading intermodal containers from container ships.
Container cranes consis ...
s are of this type.
Deck
![Caroline Delmas (2)](https://upload.wikimedia.org/wikipedia/commons/d/d7/Caroline_Delmas_%282%29.jpg)
Located on the ships and boats, these are used for cargo operations or boat unloading and retrieval where no shore unloading facilities are available. Most are diesel-hydraulic or electric-hydraulic.
Jib
![Pedestal Jib](https://upload.wikimedia.org/wikipedia/commons/d/dc/Pedestal_Jib.jpg)
A jib crane is a type of crane 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 crane
A bulk-handling Crane (machine), crane is one that, instead of a simple hook that can handle a range of slung loads, has an integral grab for lifting bulk cargoes such as coal, mineral ore etc.
Where the grab is a two-piece hinged bucket, it is k ...
s 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.
Loader
![Hydraulic Truck Crane](https://upload.wikimedia.org/wikipedia/commons/b/b0/Hydraulic_Truck_Crane.jpg)
A loader crane (also called a ''knuckle-boom crane'' or ''articulating crane'') is an hydraulically powered articulated arm fitted to a
truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...
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
A telescope is an instrument designed for the observation of remote objects.
Telescope(s) also may refer to:
Music
* The Telescopes, a British psychedelic band
* ''Telescope'' (album), by Circle, 2007
* ''The Telescope'' (album), by Her Space H ...
. 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", 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.
Stacker
A crane with a
forklift
A forklift (also called 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 century by various c ...
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 outskirts of cities ...
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
automobile
A car or automobile is a motor vehicle with Wheel, wheels. Most definitions of ''cars'' say that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, pe ...
. 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.
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,
moles Moles can refer to:
*Moles de Xert, a mountain range in the Baix Maestrat comarca, Valencian Community, Spain
*The Moles (Australian band)
*The Moles, alter ego of Scottish band Simon Dupree and the Big Sound
People
*Abraham Moles, French engineer ...
and
stone piers.
Efficiency increase of cranes
Lifetime of existing cranes made of welded metal structures can often be extended for many years by aftertreatment 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
![Film Shooting From a Crane](https://upload.wikimedia.org/wikipedia/commons/3/37/Film_Shooting_From_a_Crane.jpg)
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:
*
Block and tackle
*
Capstan (nautical)
*
Hoist (device)
*
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 of a rope or wire rope (also called "cable" or "wire cable").
In its simplest form, it consists of a spool (or drum) attache ...
*
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, a.k.a. the ''Stobcross Crane''
*: –
Category A-listed example of a "hammerhead" (cantilever) crane in
Glasgow
Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
's former docks, built by the William Arrol company.
*: – tall, capacity, built 1926
*
Taisun
*: – double bridge crane at
Yantai
Yantai, Postal Map Romanization, formerly romanization of Chinese, known as Chefoo, is a coastal prefecture-level city on the Shandong Peninsula in northeastern Shandong province of People's Republic of China. Lying on the southern coast of ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
.
*: – capacity, World Record Holder
*: – tall, span, lift-height
*
Kockums Crane
*: – shipyard crane formerly at
Kockums,
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
.
*: – 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, neighboring ...
,
South Korea
South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...
*
Samson and Goliath (cranes)
*: – two
gantry cranes at the
Harland & Wolff shipyard in
Belfast
Belfast ( , ; from ga, Béal Feirste , meaning 'mouth of the sand-bank ford') is the capital and largest city of Northern Ireland, standing on the banks of the River Lagan on the east coast. It is the 12th-largest city in the United Kingdo ...
built by
Krupp
The Krupp family (see pronunciation), a prominent 400-year-old German dynasty from Essen, is notable for its production of steel, artillery, ammunition and other armaments. The family business, known as Friedrich Krupp AG (Friedrich Krup ...
*: – ''Goliath'' is tall, ''Samson'' is
*: – span , lift-height , capacity each, combined
*
Breakwater Crane Railway
The Douglas Breakwater Crane Railway was a massive self-propelled steam block-setting crane, with a capacity of 15 tons, built by Stothert & Pitt of Bath that ran the length of the original breakwater at Douglas, also used for the loading a ...
*: – 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 W ...
.
*: – ran on gauge track, the broadest in the British Isles
*
Liebherr TCC 78000
*: – Heavy-duty gantry crane used for heavy lifting operated in
Rostock
Rostock (), officially the Hanseatic and University City of Rostock (german: link=no, Hanse- und Universitätsstadt Rostock), is the largest city in the German state of Mecklenburg-Vorpommern and lies in the Mecklenburgian part of the state, c ...
,
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
.
*: – capacity, lift-height
Crane operators
![Woman driving 20 ton O](https://upload.wikimedia.org/wikipedia/commons/0/06/Woman_driving_20_ton_O.E.T._crane_%2815402565322%29.jpg)
Crane operators are
skilled workers and
heavy equipment operator
A heavy equipment operator operates heavy equipment used in engineering and construction projects.{{cite book, title=Construction Safety Handbook , author= V. J. Davies, Ken Tomasin, year=1996, publisher=Thomas Telford, url=https://books.google.c ...
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
See also
*
Accredited Crane Operator Certification Accredited Crane Operator Certification OSHA regulation 29 CFR 1926 Subpart CC, released August 9, 2010, requires crane operators involved in construction to be certified by an accredited certification provider by November 10, 2014. An operator is d ...
*
Banksman
In Irish and British civil engineering, a banksman is the person who directs the operation of a crane or larger vehicle from the point near where loads are attached and detached. The term 'dogman' may be used in Australia and New Zealand, while 's ...
*
Cherry picker
*
Davit
Boat suspended from radial davits; the boat is mechanically lowered
Gravity multi-pivot on Scandinavia''
file:Bossoir a gravité.jpg, Gravity Roller Davit
file:Davits-starbrd.png, Gravity multi-pivot davit holding rescue vessel on North Sea ferr ...
*
Floating sheerleg
A floating sheerleg (also: shearleg) is a floating water vessel with a crane built on shear legs. Unlike other types of crane vessel, it is not capable of rotating its crane independently of its hull.
There is a huge variety in sheerleg capaci ...
*
Gantry crane
* Lifting devices with one, two, and three legs:
**
derrick
**
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 ...
**
gyn
A gyn is an improvised three legged lifting device used on sailing ships. It provides more stability than a derrick or sheers, and requires no rigging for support. Without additional support, however, it can only be used for lifting things dire ...
*
Overhead crane
*
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 front loader, a jacking device, or an erect crane. A pallet is the structural foundat ...
*
Patient lift
*
Sidelifter
*
Steam shovel
A steam shovel is a large steam-powered excavating machine designed for lifting and moving material such as rock and soil. It is the earliest type of power shovel or excavator. Steam shovels played a major role in public works in the 19th and e ...
*
Taisun
*
Telescopic handler
A telescopic handler, also called a lull, 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 cra ...
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