On an appropriate design and test standard for spherical pressure hull in a deep manned submersible

As the most critical component of a deep manned submersible, the manned pressure hull provides a safe living space for pilots and scientists under the deep sea pressure and its weight occupies almost 1/3 total weight of the manned submersible. So the pressure hull should be designed to have enough strength and should be as light as possible. However, a comparison of the current available design rules from various classification societies indicated significantly different results among these design rules and many existing spherical pressure hulls are found to be not in compliance with most of current design rules. This indicates that current design rules need to be updated and unified like Common Structural Rules for tankers and bulk carriers. In order to update the design rules, a systematic study is carried out. Then a new design and test standard based on this study is proposed to China Classification Society (CCS) for the consideration of updating their rules. The purpose of this paper is to briefly summarize the results of this research.