1 Lifting equipment is usually a large structure, complex mechanism, can complete the lifting movement, horizontal movement.
For example, the bridge crane can complete the hoisting, the cart operation and the trolley run 3 movement, the gantry crane can complete the hoisting, the luffing, the slewing and the cart run 4 movement. In the process of operation, it is often difficult to operate at the same time in several different directions.
2 Lifting equipment is carried by a variety of heavy weights, the load is variable. Some heavy weights up to hundreds of tons or even thousands of tons, some objects up to dozens of meters, the shape is very irregular, there are scattered grains, heat melts state, inflammable and explosive dangerous goods, such as the lifting process complex and dangerous.
3 Most lifting equipment, the need to operate in a larger space, some to install track and wheels (such as Tower Crane, Bridge crane, etc.), some to be loaded with tires or tracks on the ground to walk (such as car hoists, crawler cranes, etc.); some need to walk on the wire rope (such as passenger, freight aerial ropeway), the movable space is larger than 4) some lifting machinery need to carry personnel directly in the guide rails, platforms or wire rope to do lifting movements (such as elevators, lifting platforms, etc.), its reliability directly affect personal safety.
5 The lifting equipment exposed, the activity more parts, and often with the crane operators direct contact (such as hooks, wire rope, etc.), potentially many accidental risk factors.
6 The operating environment is complex. From large iron and steel joint enterprises, to modern ports, construction sites, railway hubs, tourist resorts, there are lifting machinery in operation, workplaces often encounter high temperature, high pressure, inflammable and explosive, transmission lines, strong magnetic and other risk factors, the equipment and operators to form a threat.
7 The lifting industry often needs many people to cooperate and carry out together. An operation, requiring command, banding, driving and other operators to cooperate with proficiency, movement coordination, mutual care. The operator should have the ability to deal with the emergency on site. The close cooperation between multiple workers usually has a great difficulty.