This part of GB/T 20863 is to classify the tower cranes defined in ISO 4306-3. This standard applies to the following tower cranes: - detachable tower cranes for building and general construction; - permanently installed tower cranes; - topless tower cranes; - tower cranes for docks and shipyards crane. This section does not apply to the following cranes: - mobile cranes that can be equipped with tower lifting gear; - masts for installation with or without jib.