crane is a kind of machine, generally equipped with a lifting strap, wire rope or chain, and sheaves, which can be used both for lifting and lowering materials and moving them horizontally. It is mainly used for lifting heavy objects and moving them to other places. This device uses one or more simple machines to create mechanical advantage and thereby move the load beyond the normal human capability. Cranes are generally used in the transportation industry for loading and unloading of goods, in the construction industry for material movement, and in the manufacturing industry for heavy equipment assembly.
The first construction cranes are known to have been created by the Ancient Greeks and powered by humans or burden beasts, such as donkeys. These cranes are used for the construction of tall buildings. Larger cranes are then developed, using the use of a human tread wheel, which allows lifting heavier weights. In the High Middle Ages, port storks were introduced to load and unload ships and assist its construction - some built into stone towers for extra strength and stability. The earliest cranes were built of wood, but cast iron, iron and steel took over with the coming of the Industrial Revolution.
For centuries, power has been supplied by the physical exertion of man or beast, though the hoists in the waterwheel and windmill can be driven by the forces of nature that are exploited. The first 'mechanical' power was provided by the steam engine, the earliest steam cranes introduced in the 18th or 19th century, with much of what remained in use until the late 20th century. Modern cranes typically use internal combustion engines or electric motors and hydraulic systems to provide much larger lift capabilities than were previously possible, although manual cranes are still used where power supply will not be economical.
Cranes exist in very diverse forms - each tailored for a particular use. Sizes range from the smallest jib crane, used inside the workshop, to the highest tower crane, which is used to build tall buildings. Mini-cranes are also used to build tall buildings, to facilitate construction by reaching a narrow space. Finally, we can find larger floating cranes, commonly used for building oil rigs and saving ships.
Some lifting machines do not fully fit the crane definition above, but are commonly known as cranes, such as a stacking crane and a loading crane.
Video Crane (machine)
Etymology
Derek is so called from the likeness of the bird's long neck, cf. Ancient Greek: ??????? , French grue .
Maps Crane (machine)
History
Ancient Greek
Cranes for lifting heavy loads were discovered by the Ancient Greeks at the end of the 6th century BC. Archaeological records show that no later than c.515 BC a special cuttings to lift tongs and lewis began to appear on the stone blocks of the Greek temple. Because these holes refer to the use of lifter, and since they must be found above the center of gravity of the blocks, or in pairs spaced equally from the point above the center of gravity, they are considered by archaeologists as positive. evidence required for the existence of cranes.
The introduction of winch and pulley hoist immediately led to the replacement of the wide ramps as the main means of vertical movement. Over the next 200 years, the Greek building site witnessed a sharp reduction in the weights handled, because the new hoisting technique makes the use of some smaller stones more practical than smaller ones. In contrast to the ancient period with its tendency for increasing block size, classical Greek temples like Parthenon always feature stone blocks weighing less than 15-20 metric tons. Also, the practice of establishing large monolithic columns is practically abandoned in order to use some column drums.
Although the exact state of the shift from the road to the tow technology remains unclear, it has been argued that the volatile political and political conditions in Greece are better suited to employing small and professional construction teams than large bodies of unskilled workers, making cranes more favorable than Greek policymakers rather than the more labor-intensive road that has become the norm in Egyptian or Assyrian autocratic society.
The first rigorous literary evidence for the existence of a compound pulley system appears in Mechanical Problems ( Mech .18, 853a32-853b13) associated with Aristotle (384-322 BC), but probably arranged on a slightly slower date. Around the same time, the size of the blocks in Greek temples began to emulate their ancient predecessors again, suggesting that the more sophisticated compound pulley had to find its way to the Greek construction site at the time.
Ancient Rome
The triumphal period of cranes in ancient times came during the Roman Empire, when construction activity soared and buildings reached a huge dimension. The Romans adopted the Greek crane and expanded it further. We were well informed about their appointment technique, thanks to a rather long account by the Vitruvius engineers ( De Architectura 10.2, 1-10) and Heron of Alexandria ( Mechanica 3.2- 5 ). There are also two surviving reliefs from the Roman tranwheel crane, with the Haterii tombstones from the late first century AD which are specifically detailed.
The simplest Roman crane, trispastos , consists of a single jib-beam, winch, rope, and block containing three pulleys. Thus having a mechanical advantage of 3: 1, it has been calculated that a man who works with a crane can raise 150 kg (3 puli x 50 kg = 150), assuming that 50 kg is the maximum effort a person can do for longer. time period. The heavier crane type displays five pulses ( pentaspastos ) or, in the largest case, a set of three to five pulps ( Polyspastos ) and comes with two, three or four poles , depending on the maximum load. The polyspastos , when working with four people on both sides of the winch, can easily lift 3,000 kg (3 straps x 5 pulp x 4 men x 50 kg = 3,000 kg). If the winch is replaced with a treadwheel, the maximum load can be doubled to 6,000 kg on only half the crew, since the treadwheel has a much greater mechanical advantage due to its larger diameter. This means that, compared with the construction of the ancient Egyptian pyramids, where about 50 people are required to move 2.5 stone blocks of rock onto the road (50 kg per person), the adoptive capabilities of the Roman polyspastos proved to be > 60 times higher (3,000 kg per person).
However, many of the remaining Roman buildings that have rock blocks that are much heavier than those handled by polyspastos show that the Roman's overall lift ability far exceeds that of a single crane. At Jupiter's temple in Baalbek, for example, the architrave blocks weigh up to 60 tons each, and a corner cornice block of even more than 100 tons, all raised to a height of about 19 m. In Rome, the Trajan's Column capital block weighs 53.3 tons, which should be raised to a height of about 34 m (see Trajan Column construction).
It is assumed that Roman engineers raised this extraordinary weight in two sizes (see the figure below for comparable Renaissance techniques): Firstly, as the Heron suggests, the tower is erected, the four poles arranged in rectangular shape with parallel sides , unlike the siege tower, but with a column in the center of the structure ( Mechanica 3.5). Secondly, many capstones are placed in the ground around the tower, because, despite having a lower leverage ratio than treadwheels, hats can be formed in higher quantities and run by more men (and, moreover, by draft animals). The use of some of these capstans is also explained by Ammianus Marcellinus (17.4.15) in connection with the lifting of the Lateranense obelisk at Circus Maximus (about 357 AD). The maximum lift capability of a single roller can be determined by the number of iron holes that become monoliths. In the case of the Baitbek architrave block, which weighs between 55 and 60 tons, the remaining eight holes indicate a allowance of 7.5 tons per lewis of iron, ie per roller. Lifting such heavy burdens in joint action requires considerable coordination between working groups that apply force to the capstan.
Medieval
During the High Middle Ages, the treadwheel cranes were reintroduced on a large scale after the technology fell into disuse in Western Europe with the collapse of the Western Roman Empire. The earliest reference for treadwheel (magma rota) reappeared in archival literature in France around 1225, followed by illuminated illustrations in manuscripts which may also have originated from French originating from the year 1240. In navigation, the earliest use of port cranes was documented for Utrecht in 1244, Antwerp in 1263, Brugge in 1288 and Hamburg in 1291, while in the UK the treadwheel was not recorded before 1331.
In general, vertical transport can be done safer and cheaper by cranes than with the usual method. Typical application areas are ports, mines, and, in particular, building sites where treadwheel cranes play an important role in the building of a glorious Gothic cathedral. Nevertheless, both archive and source images show that newly introduced machines such as treadwheels or wheelbarrows do not completely replace more labor-intensive methods such as ladders, wagons and wheelbarrows. In contrast, old and new machines continue to coexist in medieval construction sites and ports.
In addition to treadwheels, medieval depictions also show cranes that will be manually moved by glasses with radiating fingers, cranks and in the fifteenth century as well by glassy eyes shaped like ship wheels. To smooth the impulse aberration and get more of the dead-spots in the flywheels removal process known to be in use since 1123.
The exact process by which the treadwheel crane is reintroduced is not recorded, although its return to the construction site is undoubtedly to be seen in close connection with the revival of Gothic architecture simultaneously. The reappearance of a treadwheel crane may result from the development of a hoist engine technology from which the treadwheel is structurally and mechanically evolved. Alternatively, the medieval treadwheel can represent a deliberate invention of the Roman companion drawn from the Vitruvius' De architectura available in many monastic libraries. Its release may also be inspired, with observations of labor-saving qualities of waterwheels with early treadwheels having many structural similarities.
Structure and placement
The medieval treadwheel is a large wooden wheel that rotates around the central axle with a treadway large enough for two workers to walk side by side. While the previous 'hand-hand' wheels have fingers directly shifted to the central axle, a more advanced type of 'pin' sleeve features a gun arranged as chords onto the wheel rim, giving the possibility of using a thinner shaft and providing thus more great mechanical superiority.
Contrary to popular belief, cranes on medieval building sites were not placed on the very light scaffolds used at the time nor on the thin walls of Gothic churches that were unable to sustain the weight of the lifting and weights machines. Instead, cranes are placed in the early stages of construction on the ground, often inside the building. When a new floor is completed, and the large beams on the roof connect the wall, the crane is dismantled and reassembled on the roof beams from where it was moved from bay to bay during the construction of the dome. Thus, the cranes 'grow' and 'roam' with buildings with the result that today all the still-existing construction cranes in England are found in church towers above the dome and under the roof, where they remain after building construction to bring materials for improvement higher..
Less often, medieval illuminations also show cranes mounted on the outside of the walls with a cradle of secured engines.
Mechanics and operations
In contrast to modern cranes, medieval cranes and hoists - such as their counterparts in Greece and Rome - were mainly able to lift vertically, and were not used to move the load for a considerable distance horizontally as well. Thus, lifting work is held in the workplace in a way different from today. In building construction, for example, it is assumed that the crane lifts stone blocks either from the bottom directly into place, or from a place opposite the center of the wall from which it can send beams to two teams working at each end of the wall. In addition, the master crane that usually gives commands to the treadwheel worker from outside the crane is able to manipulate lateral movement with a small rope attached to the load. Slewing cranes that allow the rotation of the load and thus are particularly suitable for the dockwork appear at the beginning of 1340. While the ashlar blocks are directly lifted with sling, lewis or satanic brace (Germany Teufelskralle ), other objects are placed earlier in the container such as pallets, baskets, wooden boxes or vats.
It should be noted that medieval cranes rarely display ratchet or brakes to prevent the load from running backwards. This strange absence is explained by the high frictional force perpetrated by the medieval tread wheel that usually prevents the wheel from accelerating out of control.
Harbor Usage
According to the "current state of knowledge" unknown in ancient times, stationary harbors of ports were regarded as new developments of the Middle Ages. The typical port crane is a rotating structure fitted with double treadwheels. These cranes are placed docksides for loading and unloading of cargo where they replace or complement older lift methods such as saws, cranes and yards.
Two different types of port cranes can be identified with different geographical distributions: While rotary gantry cranes in the central vertical axis are commonly found on the banks of the Flemish and Dutch shores, German seas and inland ports are usually equipped with tower cranes where loose and treadwheels located in a dense tower with only a jib arm and a rotating roof. Interestingly, the stork on the dock was not adopted in the highly developed Mediterranean and port of Italy where authorities continued to rely on more labor-intensive methods to dismantle goods by way of the Middle Ages.
Unlike construction cranes where speed of work is determined by the relatively slow progress of masons, port storks usually feature double treadwheels to accelerate loading. Both treadwheels whose diameter is estimated to be 4 m or larger are mounted on each side of the axle and rotated together. Their capacity is 2-3 tons which seems to fit the usual sea cargo size. Today, according to one survey, fifteen treadwheel harbor cranes from pre-industrial times still exist throughout Europe. Several port storks specialize in the installation of poles for newly built sailing ships, such as in Gda sk sk, Cologne and Bremen. In addition to this stationary crane, floating cranes that can be flexibly applied across the harbor basin began to be used in the 14th century.
Early modern times
A lifter tower similar to ancient Rome was used for a remarkable effect by Renaissance architect Domenico Fontana in 1586 to relocate the Vatican 361 tororisk in Rome. From his report, it became clear that the coordination of rapture between the various teams of interest required considerable concentration and discipline, because, if the force was not applied evenly, excessive pressure on the rope would make them break.
Cranes are also used domestically during this period. The chimney or stove is used to swing pots and kettles over a fire and its height is adjusted by trammel.
Industrial Revolution
With the Industrial Revolution occurring, the first modern crane was installed in the port to load the cargo. In 1838, industrialist and businessman William Armstrong designed a hydraulic water-powered crane. The design uses the ram in a closed cylinder that is forced down by a pressurized liquid entering the cylinders - the valve regulates the amount of fluid intake relative to the load on the crane.
In 1845, a scheme was driven to provide tap water from a distant reservoir to a Newcastle household. Armstrong was involved in this scheme and he proposed to the Newcastle Corporations that excess water pressure at the bottom of the city could be used to move one of its hydraulic cranes for loading coal to barge at Quayside. He claims that his invention will do the job faster and cheaper than a conventional crane. The corporation approved his suggestion, and the experiment proved so successful that three more hydraulic cranes were installed on the dock.
The success of his hydraulic crane led Armstrong to establish Elswick's work at Newcastle, to manufacture his hydraulic machines for cranes and bridges in 1847. His company immediately received orders for hydraulic cranes from Edinburgh and Northern Railways and from Liverpool Docks, as well as for hydraulic machines for dock gates in Grimsby. The company expanded from a workforce of 300 and an annual production of 45 cranes in 1850, to nearly 4,000 workers producing more than 100 cranes per year in the early 1860s.
Armstrong spent the next few decades continuing to improve his crane design; - The most significant innovation is the hydraulic accumulator. Where water pressure is not available at the site for the use of hydraulic cranes, Armstrong often builds high water towers to provide water supply at pressure. However, when supplying cranes for use in New Holland at Humber Estuary, he can not do this because the foundations are sand. He eventually produces a hydraulic accumulator, an iron cylinder equipped with a plunger that supports very heavy weights. The plunger will slowly lift, pulling water, until the force downward is sufficient to force the water beneath it into a pipe with great pressure. The present invention allows a much larger amount of water to be forced through the pipe at constant pressure, thereby significantly increasing the crane load capacity.
One of its cranes, commissioned by the Italian Navy in 1883 and used until the mid-1950s, still stands in Venice, where it is now in disrepair.
Mechanical principles
There are three major considerations in crane design. First, the crane must be able to lift heavy loads; second, cranes should not collapse; third, cranes should not break.
Stability
For stability, the sum of all moments about the winch of the crane must be close to zero so the crane is not reversed. In practice, the amount of load allowed to be lifted (called "rated load" in the US) is some value that is less than the load that will cause the crane to tip, thus providing a safety margin.
Below US standards for mobile cranes, the loads restricted by stability to crane crawlers are 75% of the tipping charge. The load value limited by the stability for mobile cranes supported on the outrigger is 85% of the tipping charge. This requirement, together with additional safety aspects of crane design, is defined by the American Society of Mechanical Engineers [1] in ASME B30.5-2014 Derek Mobile and Lokomotif .
Standards for cranes mounted on ships or offshore platforms are rather tight due to dynamic loads on cranes due to ship movement. In addition, the stability of the ship or platform should be considered.
For stationary or kingpost pole mounted, moments created by boom, jib, and load are opposed by base pad or kingpost. Stress in the base must be less than the yield stress of the material or the crane will fail.
Type
Mobile
There are four main types of mobile cranes: truck mounted, rough-terrain, crawler, and floating.
Installed in truck
Crane-mounted cranes have two parts: the carrier, often referred to as lower , and the lifter component that includes the boom, referred to as above . These are mated together through the turntable, allowing the top to swing from side to side. This modern hydraulic truck crane is usually a single-engine engine, with the same engine that drives undercarriage and cranes. The top is usually turned on through the hydraulics through the turntable of the pump mounted on the bottom. In the design of older hydraulic crane truck models, there are two engines. One under pulls a crane on the road and runs a hydraulic pump for outrigger and jack. The above runs up through the hydraulic pump itself. Many older operators like the two-engine system because the seal is leaked in the older turntable crane of the older design. Hiab created the world's first hydraulic crane truck in 1947. His name, Hiab, comes from the general abbreviation of Hydrauliska Industrial AB, a company founded in Hudiksvall, Sweden 1944 by Eric Sundin, a ski producer who saw how to utilize a truck engine to a power crane through the use of hydraulics.
Generally, these cranes can travel on the highway, so there is no need for special equipment to transport cranes except for the weight or other size that is in place such as local law. If this is the case, the largest cranes are equipped with special trailers to help spread the load to a larger axle or can disassemble to meet the requirements. An example is counterweight. Often cranes will be followed by other trucks carrying counterweight issued for travel. In addition, some cranes are able to remove all the top. However, this is usually only a problem in large cranes and mostly done with conventional cranes such as Link-Belt HC-238. When working at work, the outrigger is extended horizontally from the chassis then vertically to the level and stabilizes the crane while stationary and lifts. Many tow trucks have the ability to walk slowly (several miles per hour) while suspending the load. Great attention should be taken not to swing the loads aside from the direction of travel, since most anti-tipping stability lies in the stiffness of the chassis suspension. Most cranes of this type also have a moving counterweight for outside stabilization provided by outrigger. The prolonged suspended load is the most stable, since most of the weight of the crane acts as a counterweight. The calculated factory chart (or electronic safety) is used by the winch operator to determine the maximum safe load for stationary and on-rubber work and travel speed.
The truck crane ranges in lift capacity from about 14.5 tonnes short (12.9 tonnes long, 13.2 t) to about 1,300 short tons (1,161 tonnes long, 1,179 t). Though most of it only rotates about 180 degrees, cranes that are mounted by more expensive trucks can rotate a full 360 degrees.
Crude field
Rough terrain cranes have booms mounted on undercarriage over four rubber tires designed for off-road pick-and-carry operations. Outrigger is used to equalize and stabilize the crane to lift.
This telescopic crane is a single-engine engine, with the same engine that drives undercarriage and cranes, similar to a crawler crane. Machines are usually installed in undercarriage rather than at the top, like crawler cranes. Most have 4 wheel and 4-wheel drive for tighter and more slick terrain than standard truck cranes, with fewer site preparations.
Crawler
Crane crawlers have a boom mounted on an undercarriage equipped with a series of track crawlers that provide stability and mobility. Crawler cranes vary in lift capacity from about 40 to 3,500 short tons (35.7 to 3,125.0 ton lengths; 36.3 to 3,175.1 t).
The main advantage of the crawler crane is its mobility and ready use, since the crane can operate on sites with minimal and stable improvements in its path without outrigger. The wide track spreads the load in a large area and is much better than the wheels on the ground that pass without drowning. Crawler cranes are also able to travel with loads. The main disadvantage is its weight, making it difficult and expensive to transport. Usually large crawlers must be disassembled at least into booms and cabins and driven by trucks, trains or boats to the next location.
Floating
Floating cranes are used primarily in bridge construction and port construction, but are also used for occasional loading and unloading of heavy and awkward loads inside and outside the vessel. Some floating cranes are mounted on the pontoon, others are special crane barges with lift capacities exceeding 10,000 short tons (8,929 tonnes long, 9,072 t) and have been used to transport entire bridge sections. Floating cranes have also been used to rescue the shipwrecked ships.
Crane vessels are often used in offshore construction. The largest rotating crane can be found in the Thialf SSCV, which has two cranes with a capacity of 7,100 tons (7,826 tons short; 6,988 tonnes) each. For 50 years, the largest crane was "Herman the German" at the Long Beach Naval Shipyard, one of three built by Hitler's German and captured in war. Cranes were sold to the Panama Canal in 1996 where now known as "Titan."
Other types
All terrain
The all-terrain crane is a hybrid that combines the roadability of truck-mounted maneuvers and maneuvers over rough terrain cranes. This vehicle can travel at speeds on public roads and maneuver on rough terrain at work sites using all-wheel and crab steering.
AT has a 2-9 axle and is designed to lift loads up to 1,200 tons (1,323 short tons, 1,181 tons in length).
Select and take
The pick and carry crane is similar to a cellular crane designed to travel on public roads; However, the Pick and Carry crane does not have a stabilizer or outrigger leg and is designed to lift the load and carry it to its destination, within a small radius, then it can be steered to the next job. Crane Pick and Carry is very popular in Australia where great distances are found among work sites. One of the most popular producers in Australia is Franna, who has since been bought by Terex, and now all Pick and Carry cranes are often referred to as "Frannas" even though they may be made by other manufacturers. Almost every medium-sized crane company in Australia has at least one and many companies have this crane fleet. The capacity range is usually ten to twenty tons of maximum lift, although this is much less at the end of the boom. Crane Pick and Carry have replaced jobs that are usually completed by smaller truck cranes because the set-up time is much faster. Many steel fabrication plots also use Pick and Carry cranes because they can "run" with the steel parts that are made and place them where necessary with relative ease.
Sidelifter
Derek sidelifter is a highway or semi-trailer truck, can transport and transport ISO standard containers. The lifting of the container is carried out with a parallel crane like a crane, which can lift the container from the ground or from a train vehicle.
Carry deck
The carrier deck crane is a small 4-wheel crane with a 360-degree rotating boom that is placed right in the center and the operator's cab located at one end under this boom. The back of the engine house and the area above the wheel is a flat deck. Very much an American invention, the Carry deck can carry loads in confined spaces and then load them in deck space around the cabin or machine and then move on to other sites. 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 within a short distance.
Telescopic handlers
Telescopic handlers like forklift trucks that have an extended boom of telescoping like cranes. The earliest telescopic handlers lift only one direction and do not rotate; However, some manufacturers have designed telescopic handlers that rotate 360 ​​degrees through a turntable and these machines look almost identical to Rough Terrain Cranes. The new 360-degree telescopic handler/crane model has an outrigger or stabilizer that must be lowered before lifting; However, their design has been simplified so that it can be more quickly used. These machines are often used to handle brick pallets and install trusses on many new building sites and they have eroded most of the work for small telescopic truck cranes. Many of the world's armed forces have purchased telescopic handlers and some of them are of a more expensive type. Their off-road capability and the flexibility of their sites to disassemble palettes using forks, or lifting up like cranes makes them an important part of the machine.
Port
Dry bulk or container cranes are usually located in the bay or inland areas.
Railroad
The railway cranes have flanged wheels for use on the railroad tracks. The simplest form is a crane mounted on a flat carriage. More capable devices are built with special purpose. Various types of cranes are used for maintenance work, recovery operations and loading of goods in yards and handling facilities.
Aerial
Air cranes or 'Sky cranes' are usually helicopters designed to lift large loads. Helicopters can travel to and lift in areas hard to reach by conventional cranes. Helicopter cranes are most commonly used to lift units/loads to shopping centers and altitudes. They can lift anything in their lifting capacity, (cars, boats, swimming pools, etc.). They also undertake disaster relief after a natural disaster for cleaning, and during a forest fire they can bring a large bucket of water to extinguish the fire.
Some air cranes, mostly concepts, also use aircraft that are lighter than air, such as airships.
Fixed
Exchanging mobility for greater carrying capacity and reaching higher altitudes due to increased stability, this type of crane is characterized by the fact that their main structure is immobile during the period of use. However, many can still be assembled and disassembled. The basic structure remains in one place.
Tower
Crane towers are a modern form of a balance crane consisting of the same basic parts. Fixed to the ground on concrete slabs (and occasionally attached to the sides of the structure), tower cranes often provide the best combination of height and lift capacity and are used in the construction of tall buildings. The bottom is then taped to a pole that gives the crane its height. Next, the pole is attached to the slewing unit (gear and motor) which allows the crane to rotate. Above the slewing unit there are three main parts: long horizontal jib (working arm), short counter-jib, and operator cabin.
Long horizontal jibs are part of cranes that carry loads. Counter-jib carries a counterweight, usually from concrete blocks, while jibs are holding loads to and from the center of the crane. The crane operator either sits in a taxi at the top of the tower or controls the crane by remote control of the radio from the ground. In the first case, the operator cab is usually located at the top of the tower attached to the turntable, but can be mounted on a jib, or in the center of the tower. The lifting hook is operated by a winch operator using an electric motor to manipulate the wire rope cable through the grain bundle system. Hook is located in the long horizontal arm to lift the load which also contains the motor.
To associate and release loads, operators typically work together with signallers (known as 'dogger', 'rigger' or 'swamper'). They are most often in radio contact, and always use hand signals. The rigger or dogger directs the elevator schedule for the crane, and is responsible for the security of mounting and loading.
Components
Crane towers are widely used in construction and other industries to move and move materials. There are many types of tower cranes. Although they are of a different kind, the main parts are the same, as follows:
- Column : tower main tower. It is made of steel parts connected during installation.
- Slewing unit : slewing unit is at the top of the pole. This is a machine that allows a rotating crane.
- Operation cabin : in most tower cranes, the operating cabin is just above the slewing unit. It contains operation control, LMI, scale, anemometer, etc.
- Jib : jib, or the operation arm, extends horizontally from the crane. A "luffing" jib can move up and down; Jib still has a rolling trolley that runs along the bottom side to move stuff horizontally.
- Counter jib : holds counterweight, hoist motor, drum hoist, and electronics.
- Hoist winch : Winch hoist assembly consists of the winch hoist itself (motor, gearbox, drum hoist, hoist rope, and brake), motor hoist controller, and supporting components such as platform. Many tower storks have transmissions with two or more speeds.
- Hook : hook (or hook) is used to connect material to a crane. It hangs from a good hoist strap at the end, for a luffing jib crane, or in a hoist rope belly under a trolley for a hammerhead crane.
- Weight : Large concrete Counterweight mounted to the back of the counterdeck, to offset the weight of the items raised.
Assembly
Crane towers are usually assembled by telescopic jib (mobile) cranes with greater reach (see also "stand-alone cranes" below) and in the case of tower cranes that have increased when constructing very high skyscrapers, smaller cranes ( or crane) will often be lifted to the roof of the completed tower to dismantle tower cranes afterwards, which may be more difficult than installation. Tower Cranes can often be Pedestrian Operated by remote control, so you do not need to use a taxi to Operator Crane.
Operation
Each model and the distinctive style of the tower crane has a designated lift chart that can be applied to the available radius depending on its configuration. Similar to moving cranes, tower cranes can lift objects with much larger masses closer to the center of their rotation than at their maximum radius. An operator manipulates multiple levers and pedals to control each crane function.
A stand-alone tower tower
Generally a type of tower crane operated pedestrian. Standing tower towers are transported as one unit and can be assembled by qualified technicians without the aid of larger mobile cranes. They are a lower crane that stands above the outrigger, has no counter jib, has counter weight and ballast at the base of the mast, can not climb itself, has a reduced capacity for standard tower cranes, and rarely has operator cabins.
In some cases, smaller stand-alone towers may have a permanently mounted axle to the tower section to facilitate crane maneuvering on site.
For the higher crane video, see here:
For other animations such as cranes used, see this video: (Here, a crane is used to set up a scaffold which in turn contains a gantry to lift part of the bridge tower.)
Telescopic
Telescopic cranes have an explosion consisting of a number of tubes mounted one inside the other. Hydraulic cylinders or other powered mechanisms extend or shorten tubes to increase or decrease the total length of the boom. These types of booms are often used for short-term construction projects, rescue work, lifting boats in and out of water, etc. The relative complexity of the telescopic boom allows them to adapt to many mobile applications.
Although not all telescopic cranes are mobile cranes, many of them are truck-mounted.
Telescopic tower cranes have telescopic poles and are often superstructures (jibs) above that serve as towers of cranes. Some telescopic towers also have telescopic jibs.
Hammerhead
The "hammmerhead", or giant support, crane is a fixed-jib crane consisting of tied, large, horizontal, double cantilever steel towers; the front of the cantilever or jib is carrying the lifter trolley, the jib is extended backwards to form support for the engine and weigh the weight. In addition to the lifting and spinning motions, there is a movement called "squeeze", in which the lifting trolley, with a hanging load, can be moved in and out along the jib without changing the load level. Horizontal load movement like this is a feature marked from the later crane design. These cranes are generally built in large sizes and can weigh up to 350 tons.
The Hammerkran design evolved first in Germany around the turn of the 19th century and was adopted and developed for use in British shipyards to support warship building programs from 1904 to 1914. The ability of a hammer crane to lift a heavy load is useful to install large warships such as steel plates and gun barrels. Giant cantilever cranes are also installed in naval vessels in Japan and in the United States. The British government also installed a giant cantilever crane at the Singapore Naval Base (1938) and then a copy of the crane was installed at the Sydney Island Shipyard (1951). These cranes provide repair support for fleet battles operating far from the UK.
In the United Kingdom, the engineering firm Sir William Arrol & amp; CoÃ, Ltd is a major producer of giant cantilever cranes; the company built a total of fourteen. Of the sixty built in the world, there is little left; seven in England and Scotland around fifteen worldwide.
Titan Clydebank is one of 4 Scottish cranes on Clydebank and preserved as a tourist attraction.
luffing level
Usually a crane with a hinged jib will tend to have its hooks also moving up and down as the jib moves (or luffs ). Derek luffing level is a crane of this general design, but with an additional mechanism to keep the hook level when luffing.
Overhead
The overhead crane, also known as a bridge crane, is a kind of crane where the hook-and-line mechanism runs along a horizontal beam that itself runs along two separate rails. Often in long factory buildings and walk along rails along two long walls of buildings. This is similar to a gantry crane. Overhead cranes usually consist of a single beam or double beam construction. These can be built using regular steel blocks or more complex box girder types. Pictured on the right is a single bridge girder crane box with a hoist and a system operated with a locket control. Double girder bridges are more typical when requiring a heavier capacity system of up to 10 tons. The advantages of girder box type configurations produce systems that have lower deadweight but greater overall system integrity. Also includes a hoist for lifting things, a bridge, which stretches a covered area by a crane, and a trolley to move along the bridge.
The most common use of the upper crane is in the steel industry. At each step of the manufacturing process, leaving the factory as a finished product, steel is handled by the above crane. The raw material is poured into the furnace by a crane, the hot steel is stored for cooling by the upper crane, the finished rolls are lifted and loaded into trucks and trains by the upper crane, and the manufacturer or stamper uses the upper crane to handle the steel. factory. The car industry uses overhead cranes for raw material handling. Smaller workstation cranes handle lighter loads in work areas, such as CNC mills or saws.
Almost all paper mills use a bridge crane for routine maintenance that requires heavy roll reels and other equipment. Crane bridges are used in the early construction of paper machines because they facilitate the installation of heavy iron cast iron drum dryers and other large equipment, some weighing 70 tons.
In many instances, the cost of a bridge crane can largely be offset by savings from not renting a moving crane in the construction of facilities that use a lot of heavy-duty equipment.
Gantry
The gantry crane has a hoist in a fixed engine house or on a trolley that runs horizontally along the rails, usually mounted on a single beam (mono-girder) or two beams (twin-girder). The crane frame is supported on a gantry system with equivalent beams and wheels running on a gantry rail, usually perpendicular to the direction of the trolley ride. These cranes come in a variety of sizes, and some can move very heavy loads, especially very large samples used in shipyards or industrial installations. The special version is a container crane (or "Portainer" crane, named by the first manufacturer), designed to load and unload containers brought by ships at ports.
Most container cranes are of this type.
Dek
Located on boats and boats, this is used for cargo or ship loading and loading operations where no beach dismantling facilities are available. Most are diesel-hydraulic or electric-hydraulic.
Jib
Jib derek is a kind of crane where horizontal members ( jib or boom ), which supports removable hoist, mounted on walls or to pillars mounted on the floor. Jib cranes are used in industrial locations and military vehicles. Jib can swing through the arc, to provide additional lateral movement, or repairable. Similar cranes, often called hoists, are mounted on the upper floors of a warehouse to allow items to be lifted to all floors.
Bulk handling
Bulk handling cranes are designed from scratch to carry shells or buckets, rather than using hooks and sling. They are used for bulk goods, such as coal, minerals, scrap metal, etc.
Loader
A crane loader (also called a knuckle-boom crane or articulating crane) is an electrically driven arm mounted on a truck or trailer, and used to load/unload vehicles. Many jointed parts can be folded into small chambers when cranes are not used. One or more parts may be telescopic. Often the cranes will have an automation level and can disassemble or store them themselves without operator instructions.
Unlike most cranes, the operator must move around the vehicle to see its cargo; then the modern crane can be equipped with a cable control system or a portable cable connection to complement the crane's installed hydraulic control lever.
In the UK and Canada, this type of crane is often referred to as "Hiab", in part because the manufacturer found a loading crane and first entered the UK market, and partly because the distinctive name is clearly displayed in the boom arm.
Crane rolloader is a loader crane mounted on a chassis with wheels. This chassis can ride in the trailer. Because the crane can move in the trailer, it can be a light crane, so the trailer is allowed to transport more goods.
Stacker
Cranes with forklift type mechanisms used in computer-controlled automatic repositories (known as automated storage and retrieval systems (AS/RS)). The crane moved on the track in the hallway of the barn. The fork can be raised or lowered to one of the storage rack rates and can be extended to the shelf to store and retrieve the product. The product in some cases can be as big as a car. Stacker cranes are often used in large freezer manufacturers of frozen foods. This automation avoids the need for forklift drivers to work under freezing temperatures every day.
Crane upgrading efficiency
The lifetime of existing cranes made of welded metal structures can often be extended for many years by the aftertreatment of the weldings. During the development of the crane, the load lifting rate can be significantly increased taking into account the recommendation of IIW (International Institute of Welding Technology IIW issued the "Recommendation for HFMI Treatment" Guidelines in October 2016). This causes in most cases an increase in allowable lift load and thereby improves efficiency.
Similar engines
The generally accepted definition of cranes is a machine for lifting and moving heavy objects using straps or wires hanging from a movable arm. Thus, lifting machines that do not use cables, or provide only vertical and non-horizontal motion, can not be strictly called 'cranes'.
Types of lifter machines such as winches include:
- Block and resolve
- Capstan (nautical)
- Lifter (device)
- Winch
- Windlass
- Cherry Picker
More advanced types of lifting machines are technically often known as 'cranes', regardless of the official definition of the term.
Custom example
- Finnieston Crane (aka Stobcross Crane )
- Ã, - Category A-list of hammerhead crane (cantilever) samples at the former Glasgow dock, built by the William Arrol company.
- Ã, - capacity 50 m (164Ã, ft), 175 ton (172 tonnes, 193 short tons), built 1926
- Taisun
- Ã, - double bridge crane in Yantai, China.
- Ã, - 20,000 ton capacity (22,046 short tons, 19,684 tonnes), World Record Holder
- Ã, - 133Ã,m (436Ã, ft) high, 120Ã,m (394Ã, ft) span, elevator-height 80 m (262Ã, ft)
- Derek Kockums
- Ã, - the previous towing dockyard in Kockums, Sweden.
- Ã, - 138Ã, m (453Ã, ft) high, 1,500 tons (1,500 tonnes, 1,700 short tons) capacity, since moving to Ulsan, South Korea
- Samson and Goliath (cranes)
- Ã, - two gantry cranes in Harland & amp; Wolff shipyard in Belfast built by Krupp
- Ã, - Goliath is 96 m (315 ft), Samson is 106 m (348 ft)
- Ã, - span 140Ã, m (459Ã, ft), high-lift 70 m (230Ã, ft), capacity 840 tons (830 tons long; 930 tons short) respectively, 1,600 tons (1,600 tons tons; 1,800 short tons) combined
- Breakwater Railway
- Ã, - a self-powered steam crane that had previously run the length of the breakwaters in Douglas.
- Ã, - ran on a 10 foot (3.05 m) gauge, the largest in the British Isles
Crane operator
Crane operators are skilled workers and heavy equipment operators.
See also
- Raise the patient
- Banksman
- Davit
- Gantry crane
- Overhead crane
- Certification of Accredited Crane Operators
- Lifting devices with one, two, and three feet: cranes, sheers, and gyn
- Pallet
- Steamers
- Cherry Picker
- Sidelifter
- Taisun
References
Source
Crane history Coulton, JJ (1974), "Lifting in Early Greek Architecture", The Journal of Hellenic Studies , Coulton, JJ (1974) 94 : 1-19, doi: 10.2307/630416, JSTORÃ,630416
Source of the article : Wikipedia
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