Crane History

In 10 BC, the ancient Roman architect Vitruvius described a lifting machine in his architectural manual. This kind of machinery has a mast with a pulley on the top of the pole. The position of the mast is fixed by a guy rope, and a winch is used to pull the cable passing through the pulley to lift the heavy object. Some overweight machinery can use two masts to form a herringbone shape to move the hoisted object laterally, but the range is very small and the operation is very difficult.
It was not until the 15th century that Italy invented the jib crane to solve this problem. This kind of crane has an inclined cantilever arm with a pulley on the top of the arm, which can both lift and rotate. But until the 18th century, all kinds of lifting machinery used by humans were powered by human or animal power, and were very limited in terms of lifting capacity, scope of use and work efficiency.
In the mid-to-late 18th century, after the British Watt improved and invented the steam engine, it provided power conditions for lifting machinery. In 1805, Glen engineer Lennie built the first steam cranes for the London dockyards. In 1846, Britain's Armstrong converted a steam crane at the Newcastle Dockyard into a hydraulic crane.
In the early 20th century, tower cranes began to be used in Europe.
Crane mainly includes hoisting mechanism, operating mechanism, luffing mechanism, slewing mechanism and metal structure. The hoisting mechanism is the basic working mechanism of the crane. It is mostly composed of a suspension system and a winch, and some also use a hydraulic system to lift and lower heavy objects. The operating mechanism is used to transport heavy objects longitudinally and horizontally or adjust the working position of the crane. It is generally composed of a motor, reducer, brake and wheel. The luffing mechanism is only equipped on jib-type cranes. The amplitude decreases when the jib is raised and increases when it is lowered. It is divided into two types: balanced luffing and unbalanced luffing. The slewing mechanism is used to rotate the boom and is composed of a driving device and a slewing support device. The metal structure is the skeleton of the crane. The main load-bearing parts such as bridges, booms and gantry can be box structures, truss structures, or web structures, and some can use shaped steel as supporting beams.