Cranes come in an enormous variety of sizes and forms, each one designed for a specific lifting task.
A mobile crane is designed to easily transport to a work site with little or no setup required. They are mounted on a rubber tired carrier or tracks. Whereas other types of cranes maybe assembled on the job or in the work space. A basic type of mobile crane consists of a telescopic boom mounted on a mobile platform. Also, the mobile platform maybe designed for road, rail, or water use. Whatever the platform used, the working part or crane is usually mounted on a turntable allowing swing from side to side.
Cranes operate with a cable control or hydraulic system with a telescopic boom allowing the boom to easily expand or contract to the desired distance out. Also a crane is generally equipped with a hoist rope, chains or wire ropes, and sheaves, suspended from a boom that is used both to lift and lower materials vertically and horizontally.
The first hydraulic crane
In 1947, Hiab (a Swedish company) invented the world's first truck mounted hydraulic crane. Hiab found a way to utilize the truck's engine to power loader cranes, using hydraulics.
Cranes come in a variety of sizes, from a small jib crane (used in workshops), to a massive tower crane for the construction of tall buildings. Smaller or mid-sized cranes are also used in construction to operate in smaller or tighter areas.
Then there are the floating cranes used in salvage at sea or for aiding in the building of oil rigs.
A crane is mainly used for lifting heavy things and moving or carrying them to other places. With the use of leverage and pulleys a crane can move loads far beyond the normal capability of a human. Cranes are commonly used for unloading and loading freight. Also for the placement or assembly of heavy equipment in the construction trade.
In addition, cranes can be converted by adding a demolition ball for all types of demolition or adding a clamshell to move material. Also, a dragline and scoop can be fitted to the hoist rope to make it a very versatile earthmoving machine.