Crane type of work

Crane types of work: refers to how busy working crane and loading degree of change parameters.
     How busy work, the  bridge gantry crane  terms, this means the total time in a year, the actual operation of the crane and the total number of hours when the ratio of the number; against institutions, it refers to an institution operating hours within a year the ratio of the total number of hours. A work cycle of the crane, the agency running time percentage, called the agency's duty cycle, expressed by JC. Changes in load level, according to the design rated capacity of the crane in the actual operation, the crane lifting loads are often less than the rated capacity. The degree of this change in load lifting capacity utilization factor k. k = crane year's actual average starting weight / crane's rated capacity.
     According to the work of the crane and the load busy the degree of change, the type of work the crane usually divided into: light, intermediate, heavy and extra heavy duty grade four levels.
     The type of work the crane and lifting capacity are two different concepts, lifting capacity, is not necessarily a weight class, from the weight of a small, not necessarily light level. Such as hydropower  eot crane  lifting capacity with hundreds of tons, but not much chance to use only the installation unit, used only when repairing the unit, and the remaining time stop there, so even though from the weight of large, but still belongs to light level . Another example is the use of the station yard  gantry crane, although from the weight of small, but very busy, are heavy duty type.