Crane machine
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Crane machine |
A crane is a type of machine, usually equipped with a hoist cable or chain, pulleys and which can be used both to raise and lower materials and to move them horizontally. It is mainly used for heavy lifting and transport them elsewhere. One or more simple machines are used to create mechanical advantage and move loads beyond the normal capability of a human being as well. Cranes are commonly employed in the transport industry for the loading and unloading of goods in the construction industry for the movement of materials and in the manufacturing industry for the assembling of heavy equipment.
The first cranes were invented by the ancient Greeks and powered by men or beasts of burden, such as donkeys. These cranes were used for the construction of tall buildings. Large cranes later developed, employing the use of human treadwheels, allowing the transport of heavy loads. In the High Middle Ages, harbor cranes were introduced to load and unload ships and assist with their construction - some were built into stone towers for strength and stability. The first cranes were constructed from wood, but cast iron and steel took over with the arrival of the Industrial Revolution.
For many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the natural power operated. The first power "mechanical" was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, with many remaining cranes and modern 20th century generally use motors internal combustion or electric motors and hydraulic systems to provide greater lift capacity than was previously possible, although manual cranes are still used where the supply of energy would not be profitable.
Cranes come in a variety of shapes - each adapted to a specific use. Sometimes sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes, used for constructing high buildings. For a while, mini - cranes are also used for constructing high buildings, in order to facilitate constructions by reaching tight spaces. Finally, we can find large floating cranes, generally used to build oil and salvage sunken ships platforms.
Some cranes are not strictly fit the above definition of a crane, but are generally known as cranes, such as cranes, forklifts and cranes loading.
The first cranes were invented by the ancient Greeks and powered by men or beasts of burden, such as donkeys. These cranes were used for the construction of tall buildings. Large cranes later developed, employing the use of human treadwheels, allowing the transport of heavy loads. In the High Middle Ages, harbor cranes were introduced to load and unload ships and assist with their construction - some were built into stone towers for strength and stability. The first cranes were constructed from wood, but cast iron and steel took over with the arrival of the Industrial Revolution.
For many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the natural power operated. The first power "mechanical" was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, with many remaining cranes and modern 20th century generally use motors internal combustion or electric motors and hydraulic systems to provide greater lift capacity than was previously possible, although manual cranes are still used where the supply of energy would not be profitable.
Cranes come in a variety of shapes - each adapted to a specific use. Sometimes sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes, used for constructing high buildings. For a while, mini - cranes are also used for constructing high buildings, in order to facilitate constructions by reaching tight spaces. Finally, we can find large floating cranes, generally used to build oil and salvage sunken ships platforms.
Some cranes are not strictly fit the above definition of a crane, but are generally known as cranes, such as cranes, forklifts and cranes loading.
