The Diving Bell
Dr. Maillot had the great idea of blogging about the history of underwater exploration, inspired partially by the awesome 16th century painting of Alexander the Great being lowered in a diving bell. According to Wikipedia, the first account of diving bells was a description by Aristotle in the 4th century BC, making it the oldest known form of underwater breathing apparatus. Aristotle explained “…they enable the divers to respire equally well by letting down a cauldron, for this does not fill with water, but retains the air, for it is forced straight down into the water.”
The basic idea is to have a big bell with a guy inside and lower it into the water so the pressure of the water holds the air in the bell. They are always attached to a tether, and to keep them full of air at depth, air must be pumped into them from the surface. Any excess air bubbles out the bottom, making it an open circuit system.
After some design improvements in 1535 by Guglielmo de Lorena, numerous innovations followed in the 1600’s, when they were used for salvage operations, recovering canons and treasure. Today, diving bells are still used by commercial divers, particularly for diving to great depths, like on deep sea oil rigs. However, it is more common now to use sealed diving chambers, although they may be attached to a diving bell for access to the water.a
In the gallery below is the aforementioned painting, as well as a diagram of a diving bell, a diving bell from a Swedish maritime museum and the SAT system diving bell, used as a taxi to take divers to their saturation diving living quarters by the NOAA.
