The original Amphibian MK1 for underwater use and in poison gas
Figures 1 and 2, the original “Amphibian” dual-purpose apparatus, i.e., for use in poison gas or under water, consists of a steel cylinder, charged with pure oxygen for depths not exceeding 30 feet; CO2 absorbent chamber, mouthpiece, nose clip, goggles, a stream-lined breathing bag, with excess air escape valve; and—for use under water only—a lead balance-weight at back, jock strap, etc. For use at greater depths, a mixture of oxygen and air, or of oxygen and helium is used in certain proportions according to the depth at which the diver has to work. In some cases the gases are in separate cylinders, each with its own reducing valve set to deliver the gases in correct proportion.
In the modified “Amphibian” apparatus (Fig. 3), the excess air or exhaust valve is fitted in front of the wearer, over his shoulder, so as to be more readily accessible. While still of the automatic type, like the more remotely-placed valve (Fig. 2), the new arrangement also enables the valve to he controlled by hand.
Therebreathersite was founded by Jan Willem Bech in 1999. After a diving career of many years, he decided to start technical diving in 1999. He immediately noticed that at that time there was almost no website that contained the history of closed breathing systems. The start for the website led to a huge collection that offered about 1,300 pages of information until 2019. In 2019, a fresh start was made with the website now freely available online for everyone. Therebreathersite is a source of information for divers, researchers, technicians and students. I hope you enjoy browsing the content!