Japan is of the opinion that it is necessary to clarify the requirements for the carriage of dangerous goods by such ships
Possible problems
3 Some of the possible problems in case of applying the requirements for stowage and segregation(paragraph 15.3.3 of general introduction to the IMDG Code)of freight containers packed with dangerous goods in open-top cargo holds to cargo holds with partially weatherproof hatchway covers are as follows'
.1 The principle of "not in the same verticalline"in the segregation requirements of "separated from 2"for "closed versus closed" for open-top cargo holds is not applicable to such holds as illustrated in figure l, which is a graphical expression of segregation resulting from direct application of the principle to such holds, and it is deemed necessary to segregate more appropriately in covered holds, e.g., as illustrated in figure2；and
.2 Though the stowage of dangerous goods as "on deck only" is prohibited for open-top holds, It is deemed appropriate that some types of dangerous goods, such as solids, gases or vapors lighter than air can be stowed on partially weatherproof hatchway covers.
It can, therefore, be said that the stowage and segregation requirements of freight containers for open-top cargo holds should not be applied to such holds without consideration in detail. Thus, it is deemed appropriate to add special requirements, as necessary, for such cargo holds based on the particular requirements of cargo holds of ordinary container-ships, because such cargo holds are fitted with hatchway covers, even though they are notfully water tight, and are significantly different from open-top holds.
