Overhead cranes are hoisting equipment that is horizontally placed over workshops, warehouses and stockyards for material hoisting. Because its two ends sit on tall concrete columns or metal supports, it is shaped like a bridge. The bridge of the bridge crane runs longitudinally along the track laid on the elevated on both sides, which can make full use of the space under the bridge to lift materials without being hindered by ground equipment. It is the most widely used and the largest number of hoisting machinery.

Some of the working characteristics of lifting equipment are intermittent movement, that is, the corresponding mechanisms for taking materials, moving, and unloading in a working cycle work alternately. The development and use of cranes in the market are becoming more and more extensive. Due to the fact that some accidents often occur when driving without outriggers and hoisting, the driving speed is also faster than that of crawler cranes (crawlers); the operation is stable, the lifting capacity is large, and the weight can be lifted within a specific range, but the road must be smooth and solid. , The tire pressure meets the requirements, and the lifting off the ground should not exceed 50CM; it is forbidden to walk long distances with a load. In order to ensure the safety of the operation, it is basically forbidden in China to carry out hoisting operations without outriggers. The types of steel wire ropes used by cranes include phosphating coated steel wire ropes, galvanized steel wire ropes and smooth steel wire ropes.