Classification of marine crane devices

The crane devices can be divided into two categories: light and heavy. The lifting capacity is less than 10 tons for light crane devices, and more than 10 tons for heavy crane devices. The lifting capacity of the crane is determined by the purpose of the ship. The lifting capacity of the light crane of a general dry cargo ship is 3 to 5 tons for single-lever operation, and 1.5 to 3 tons for double-lever operation; the lifting capacity of a 10,000-ton dry cargo ship can reach 10 tons for single-lever operation, and 5 tons for double-lever operation. Modern multi-purpose ships need to load and unload containers, and the lifting capacity of the crane should be at least able to lift a 20-foot container (20 tons). Heavy cranes are used to load and unload heavy and bulky goods such as large machinery, locomotives and vehicles. Generally, only 1 to 2 cranes are installed on cargo ships, and the lifting capacity is mostly 10 to 60 tons, and there are also 60 to 150 tons, and a few reach 300 tons. Generally, each cargo hold of a dry cargo ship has two light cranes; each cargo hold of a giant dry cargo ship is often equipped with four light cranes.