Russian IDA71 military and naval rebreather
Encyclopedia
The Russian IDA71 military and naval rebreather is an oxygen rebreather
intended for use by naval and military divers. As supplied it is in a plain backpack harness with no buoyancy aid. Its casing is metal, not plastic. It has a small optional diluent cylinder which can be clipped on its outside to convert it to nitrox mode. It contains one oxygen cylinder and two absorbent canisters. In the bottom of its casing is an empty space which is intended for an underwater communications set.
Here, "up", "back", etc refer to a man wearing the set standing on land.
It gets thinner towards the lower end, to avoid the frogman
being slowed by hydrodynamic drag as he swims. (One rebreather maker tested a rebreather with a big plain rectangular box backpack and found that its big flat stern end cut his swimming speed by half a knot.)
On the front of the harness is a projecting metal plate. This is said to be to clip a limpet mine
to. The front of the harness is a thick tough rubber "apron" which would protect much of the frogman's belly from blows from the front.
The loop of each breathing tube
can be strapped down to the shoulder to keep it under control to stop it from catching on things or being easily grabbed from behind.
On each side of its casing is a small clip to fasten a parachute to.
It can run as an ordinary diving rebreather
. Or it can be run with one of its two absorbent canisters filled with potassium
superoxide
, which gives off oxygen as it absorbs carbon dioxide: 4KO2 + 2CO2 = 2K2CO3 + 3O2; in this mode the oxygen cylinder is a bailout. This mode gives the set more duration underwater, but is dangerous and not to be risked by civilians because of the explosively hot reaction that happens if water gets on the potassium superoxide; whereas ordinary modern diver's rebreather absorbents have been designed to avoid producing a caustic solution (commonly called "cocktail") if they get wet. Tests at the United States Navy Experimental Diving Unit
in Panama City, Florida
showed that the IDA71 could give significantly longer dive time with superoxide in one of the canisters than without.
Rebreather
A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycled exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where...
intended for use by naval and military divers. As supplied it is in a plain backpack harness with no buoyancy aid. Its casing is metal, not plastic. It has a small optional diluent cylinder which can be clipped on its outside to convert it to nitrox mode. It contains one oxygen cylinder and two absorbent canisters. In the bottom of its casing is an empty space which is intended for an underwater communications set.
Here, "up", "back", etc refer to a man wearing the set standing on land.
It gets thinner towards the lower end, to avoid the frogman
Frogman
A frogman is someone who is trained to scuba diving or swim underwater in a military capacity which can include combat. Such personnel are also known by the more formal names of combat diver or combatant diver or combat swimmer....
being slowed by hydrodynamic drag as he swims. (One rebreather maker tested a rebreather with a big plain rectangular box backpack and found that its big flat stern end cut his swimming speed by half a knot.)
On the front of the harness is a projecting metal plate. This is said to be to clip a limpet mine
Limpet mine
A limpet mine is a type of naval mine attached to a target by magnets; they are so named because of their superficial similarity to the limpet, a type of mollusk....
to. The front of the harness is a thick tough rubber "apron" which would protect much of the frogman's belly from blows from the front.
The loop of each breathing tube
Breathing tube (in breathing apparatus)
A breathing tube is a flexible tube for breathing through, as part of a scuba set or other breathing apparatus or a medical oxygen apparatus or anaesthetic apparatus They are wide, and usually corrugated to let the user's head move about without the tube pinching at...
can be strapped down to the shoulder to keep it under control to stop it from catching on things or being easily grabbed from behind.
On each side of its casing is a small clip to fasten a parachute to.
Rebreather
A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycled exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where...
. Or it can be run with one of its two absorbent canisters filled with potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
superoxide
Superoxide
A superoxide, also known by the obsolete name hyperoxide, is a compound that possesses the superoxide anion with the chemical formula O2−. The systematic name of the anion is dioxide. It is important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature...
, which gives off oxygen as it absorbs carbon dioxide: 4KO2 + 2CO2 = 2K2CO3 + 3O2; in this mode the oxygen cylinder is a bailout. This mode gives the set more duration underwater, but is dangerous and not to be risked by civilians because of the explosively hot reaction that happens if water gets on the potassium superoxide; whereas ordinary modern diver's rebreather absorbents have been designed to avoid producing a caustic solution (commonly called "cocktail") if they get wet. Tests at the United States Navy Experimental Diving Unit
United States Navy Experimental Diving Unit
The United States Navy Experimental Diving Unit is the primary source of diving and hyperbaric operational guidance for the US Navy...
in Panama City, Florida
Panama City, Florida
-Personal income:The median income for a household in the city was $31,572, and the median income for a family was $40,890. Males had a median income of $30,401 versus $21,431 for females. The per capita income for the city was $17,830...
showed that the IDA71 could give significantly longer dive time with superoxide in one of the canisters than without.