1. Improve production efficiency. For example, before the birth of the grab crane, the wharf was used for loading and unloading mineral powder, and 12~ 16 workers were used in the ship cabin, each with a shovel, and each group took a large leather mesh bag and shoveled the mineral powder into the large leather mesh bag one by one. A mesh bag can hold up to 4 tons of goods. When the net bag is full, lift it with a crane. A warehouse can only dry up to 200 tons of goods in 8 hours. At present, the large ship unloader can unload more than 2000 tons of ore per hour, which greatly improves the production efficiency.

2. Improve production safety. For example, before the birth of grab cranes, 4-6 workers were used to load and unload logs at the dock. First, a small steel wire rope passes through the gap in the cross section of the log pile to form an estimated area. Then hang both ends of the small steel wire rope on the hook of the crane at a distance of1~ 2m, so that one end of the log is inclined, and then the worker takes one 16~28. Throw it out from the gap between the hoisted end and the pile, and the workers at the other end should catch it quickly, otherwise the wire rope will slide into the groove of the pile, and the workers throwing the wire rope should pull it up before throwing it, or the workers at the other end should pick it up with a tool with a hook on a long stick, and then hang the hook on the wire rope to bind the log ... In this process, the log may roll and hurt the workers' hands and feet, or it may be that the workers tied the log too much and the wire rope is in the air. Later, Bao invented timber grab, which greatly reduced personal injury accidents.