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What are life support systems for deep sea vessels

what-are-life-support-systems-for-deep-sea-vessels-photoAt the start of the 1960s there were only four deep-sea research vessels in the world, but by 1970 there were 43, mainly funded by investment from the U.S. government. However, in the 1970s and 1980s the pace of new investment in these specialized vessels has slackened. Instead, submersibles have moved firmly into the commercial sphere and are now used for marine engineering projects and exploration.

Life support systems used in submersibles are generally simpler than those found in larger submarines. Cost, size and mission length have all had an influence on the design of these systems. Free-swimming submersibles usually have both oxygen supply and carbon dioxide removal systems, but those lowered from surface vessels often economize by only having an oxygen supply system. Consequently, dives are limited to only an hour or two. Oxygen is usually supplied from cylinders, and carbon dioxide removal is carried out by Barylyme or lithium hydroxide scrubbers. Air pressure is carefully maintained at that found at sea level, and normal Earth atmosphere gas constituents are aimed for, which is easier for the crew.

Deep-sea submersibles normally hold two divers. Sufficient air supply for a dive lasting 24 hours is normally carried if very deep dives are the order of the day, to avoid having to return to the surface.

Power limitations imposed by the batteries used in submersibles often mean that heating and humidity control are not present – although silica gel has been used to absorb some of the humidity produced by breathing. Because of these restraints, submersibles are not always the most comfortable way for humans to go down in the sea.