The Internation Maritime Organization (IMO) has required that ships other than cellular-ships which carry cargo units and other entities should be provided with a cargo securing manual. A number of serious accidents has resulted from improper stowage and insufficient securing of heavy cargo. The cargo claims caused by the accidents stated above not only reduce the number of shippers but also reduce their benefits. The following four basic safe items should be considered carefully in the carriage by sea in case of two tiers loading of heavy cargoes packed with wooden case if it is a general cargo ship. a) Safe stowing place b) Safe lashing c) Protecting crushing goods d) Adequate dunnage. All operators of cargoes must be reminded that only the proper stowge and securing of heavy cargos can prevent from the occurrence of such accidents in the future. This paper intends to analyze the unigue damage mechanism for two tiers loading of heavy cargoes on the general cargo ships encountered in the rough sea, and suggest the countermeusere to prevent the identical accidents in the future.