This document specifies the terms and definitions, structure, classification and model, basic parameters, basic requirements, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of bulk cement screw ship unloaders (hereinafter referred to as ship unloaders) ,quality promise. This document is applicable to screw ship unloaders that unload shipping bulk cement. It is not applicable to ship unloaders that unload large-diameter block and irregular-shaped materials such as coal and gravel. Ship unloaders that unload other powdery and granular uniform materials can be used as a reference.