A hydraulic crane is a machine which is used for hoisting and moving heavy materials. Generally cranes are equipped with a winder, ropes, chains and sheaves. Hydraulic cranes are usually used in transport, manufacturing and construction industries. They are of great help during natural disasters like hurricanes, floods and earthquakes. Cranes come in various sizes. Small jib cranes are used in workshops. Large floating cranes are used in construction of bridges.
The rough terrain crane, side-lift crane, truck-mounted crane, crawler crane, all terrain crane, tower crane, railroad crane, floating crane, jib crane, aerial crane, self erecting crane, telescopic crane, overhead crane, hammerhead crane, level luffing crane, gantry crane, loader crane, deck crane, bulk handling crane and stacker crane are various types that are used all over the world. Liebherr, Cargotec, Konecranes, Tadano and Zoomlion are some world class crane manufacturing companies.
A hydraulic crane is a large flexible structure. It is very simple by design. It uses fluid power to work. Like how gas is the powering medium in pneumatics, liquid is the powering medium in hydraulics. Hydraulic fluid is transmitted throughout the crane to various hydraulic motors and hydraulic cylinders. Petroleum oil (with various additives) is usually used as hydraulic fluid. The fluid is distributed using tubes and hoses. The path taken by hydraulic fluid is called the hydraulic circuit. There are many types of hydraulic circuits. Open center circuits and close center circuits are more common. Pressure is created as per requirement. The flow of the fluid is regulated by control valves.
A hydraulic crane is controlled by a system that is operated by a crane operator. Commands issued by the crane operator are translated into the motion of a wide array of actuators, which in turn move the mechanical structure. Hydraulic cranes are popular becausea large amount of power can be transferred through flexible hoses and small tubes.
Hydraulic crane accidents happen every year. Electrocution and equipment failure are two major reasons of crane accidents. Only trained people should be allowed to operate the crane. These cranes are mechanical equipments. They have to be maintained. Lifting weights beyond the recommended capacity should be avoided. Appropriate hydraulic crane safety devices have to be installed.