ANNEX
REPORT OF INVESTIGATION ON STOWAGE AND SEGREGATION REQUIREMENTS FOR FREIGHT CONTAINERS ON CONTAINERSHIPS WITH PARTIALLY WEATHERPROOF HATCHWAY COVERS
Ship Research Institute, Ministry of Land, Infrastructure and Transport
1 Outline of the work
The Sub-Committee on Dangerous Goods, Solid Cargoes and Containers (DSC) of the International Maritime Organization (IMO), at its 5th session, agreed to develop stowage and segregation requirements for freight containers on container ships with partially weatherproof hatchway covers and Members were invited to submit comments and proposals on this issue to the 6th session. Ship Research Institute, Ministry of Land, Infrastructure and Transport, with the cooperation of the Dangerous Goods Working Group of The Japanese Shipowners' Association, investigated and considered the requirements for such ships. This paper is the report of the investigation. The investigation consisted of the following steps:
(1) to review the basic principles of the stowage and segregation requirements in the existing International Maritime Dangerous Goods Code (IMDG Code);
(2) to consider the principles for stowage and segregation of freight containers packed with dangerous goods on container ships with partially weatherproof hatchway covers;
(3) to develop the stowage and segregation requirements for such ships in accordance with the principles; and
(4) to check the practicality of the stowage and segregation requirements through the trial stowage planning.
Steps (2) to (4) have been repeated until practical requirements were developed.
2 Basic understanding on stowage and segregation requirements for freight containers on container ships with partially weatherproof hatchway covers
Container ships with partially weatherproof hatchway covers, of course, have hatchway covers. The difference between the structures of such ships and those of conventional container ships with weatherproof hatchway covers is small. The difference in structure is the existence of clear gaps between hatchway covers. The gaps between hatchway covers are less than 50 mm, in general. For these reasons, we considered that the stowage and segregation requirements for container ships with partially weatherproof hatchway covers should be developed based on the requirements for conventional container ships with weatherproof hatchway covers, taking the effect of the clear gaps into account.
For the development of stowage and segregation requirements, there are the following three issues on which the effect of the gaps should be considered:
