SCR rebreather RAY Dolphin Atlantis


Among the first ideas for achieving a self-contained breathing apparatus underwater there was precisely to breathe into a leather bag, a reserve airto bring underwater. Since Roman times, there was an organization of divers, established in the ports, known as "urinatores" precisely because of lot of leather from which they breath some "fresh air"underwater.
The next image refers to a joke ordered by Cleopatra: A diver is attaching a salted cod to the fishing line of Marc'Antonio, fishing enthusiast.


The first autonomous device was made in 1876 by Henry Fleuss. This was made up of a rubber mask, connected to a bag, which was fed with oxygen from a cylinder of copper, carbon dioxide was absorbed by a filter made with fiber cordage imbued with the caustic potash. Fleuss proved his achievement, remaining in a tank of water for about an hour and then at the bottom of a bay 5.5 meters deep.
With this apparatus, the diver Lambert, instructed by Fleuss, managed to close its doors in a tunnel under construction, invaded by the muddy waters of the Severn river. "

tauchretter 1910
In 1909 the mechanical engineer Hermann Seltzner began his collaboration with the Dräger company that deals with the development of underwater breathing equipments .
In summer 1910 the French submarine "Pluvoise" suffers an accident in which all the crew was lost, on that occasion the dott.Bernard Dräger asks Seltzner to develop a device for saving submariners. From this collaboration will create the "Tauchretter" (Savior of divers), an oxygen Rebreather that anticipates the developments in this field brought forward by the British.



In 1915, taking their cue from Fleuss ideas, Sir Robert Davis will form the first apparatus to escape from submarines that will be copied throughout the world.
In the picture of its evolution in years'30


Until the completion of the Fleuss' apparatus, technology and materials have not allowed more than " to connected a pipe to any helmet": the classic Hard hat helmet lasted until today, with the parentheses of the autonomous helmet from Draeger and Fleuss-Davis.
In 1912 Dräger produces DM40, the first continuous flow "Nitrox" mixed gas Rebreather. This revolutionary Rebreather wass applied to a diving helmet (no mask or fins nor). The DM40 was, selfmixing too: a flow of oxygen, constant with the depth was combined with a flow of air (diluent) which significantly increasing with pressare, allows a leaner mixture with depth increasing.

In the'30s the U.S.Navy lieutenant Charles Momsen, develops an oxygen Rebreather (Momsen Lung) to escape from damaged submarines. This of cyclical kind: it has a hose for inhalation and one for exhalation. In the systems with a single hose a certain amount of carbon dioxide remains in the hose during exhalation and then is reinspired. The cyclical system avoids the inhalation of this amount of carbon dioxide.
The lieutenant Momsen was also the inventor of the bell that allows saving submarines' crews by high depth, pioneering the use of mixtures of helium-based and inventor of the special diving hemet DESCO Helium. Momsen's inventions were tested succesflully when, in 1934, the submarine "Squalus", remained trapped 80 meters, enabling the rescue of the crew and the subsequent salvage of the submarine itself.



The use of military Rebreather oxygen, had its roots in Italy, in the period between the two World Wars. It bears witness to the fortuitous discovery of a catalog company "Anonima Bergomi, who advertised his oxygen breathing apparatuses: " Diving Model "and" a "Submarine's model". The one for diving had a cylinder to 150 bar and an .. overpressure valve!
In 1933-34 the Navy divers Military Italian Teseo Tesei and Elios Toschi sense the importance of the use of this equipment in military operations, so that, with subsequent refinements, quest'apparato known in Italy as "ARO" (AutoRespiratore ad Ossigeno - Selfcontained Oxygen Breathing Apparatus), will be the protagonist of deeds of "Gamma Men" and those of "Maiali" (Maili means: pigs.) the "Maiali" were slow speed torpedoes, with explosive detachable head, which was ridden by divers rangers). Oxygen rebreathers are again in use nowadays for stealth operations beacause of the doesn't produces bubbles.

ARO Pirelli Polifemo

Before the Second World War were already present in Italy, companies that produce artisan ARO, they, thanks to an initiative by the Navy, merged into a single group called SIAS. Subsequently, the SIAS was named salvas, headquartered in Rome and some time later moved its offices in Castelnuovo di Scrivia, which still operates.
In the postwar ARO continued to be the protagonist of traditional Italian diving:
The "Pirelli", already the supplier of Italian Navy during World War II, producing two models of ARO as "Poseidon" and "Polyphemus," while the fledgling "Cressi" market the "model 47" probably dating their the year 1947.

ARO Cressi 57B

.At the "model 47" followed the 57 (1957) and then the "57b", who wrote the front pages of Italian underwater sports and has become a "classic" for collectors.

SuperARO Cressi

For the Italian Navy, Cressi firma produced "SuperARO" with twin cylinders and bigger counterlung and scrubber
Despite the oxygen rebreathers has always been the limit depth of use and then use has been mainly military, for a long time was the most technologically advanced equipment, in fact, they where in use after the end of warfare.



In the immediate postwar period, several ships, sunked during the conflict, did lay on the sea bottom. Inside them was a lot of valuable goods, essential for an economy where everything was missing.
The oxygen rebreather, which was the only autonomous apparatus then available, was often used to rescue this values", where a hard hat diver would never have been able to get behind dragging an hose. So some experts, often former rangers now unemployed, (like telling the Gold Medal. Luigi Ferraro, in the book: "An Italian" by Gaetano "Ninì"Cafiero), recruiting a new war against ' ancient civilization of divers: Counterlungs against hoses, rubber masks against copper helmets, fins against leaded shoes. The operational limit depth, already much more stringent than that felt good today, had broken with the dangerous practice of inflating the counterlung with air (instead of the correct practice to flush counterlung with pure oxygen), thus they breath an unknown nitrogen-oxygen mixture.


Nuovo ARO technisub

In the years to follow, the Luigi Ferraro, nicknamed "the Professor", remains the protagonist of diving in Italy and founded the "Technisub" will be thanks to his fervent mind that the Technisub, implement, in the'70s the "New ARO", an oxygen rebreather characterized by very innovative technical solutions, the most great tribute to the history and tradition of the "ARO"(oxygen rebreathers)into Italy.



In 1937 French Navy was interested in developing a self-contained closed-circuit pure oxygen through the transformation of a breathing system "Fenzy" which was used for interventions in polluted atmospheres. The trial was stopped when the diver who experienced the equipment was seized from convulsions to 15 meters deep. Earlier the blame was attributed to the accumulation of CO2, but then came up again the issue, despite the use of a filter more efficient: it was 1939 and further tests were set aside any outbreak of war.

The next image shows the evolution of French ARO: the oxygers 1954



In 1946, the French Navy founded the "GERS" (Groupe d'Etudes et de Recherches Sous-Marines) and resumed its planned construction of a closed-circuit apparatus (actually, semi) aware of the toxicity of oxygen under pressure, decided to supply the apparatus with a nitrogen-oxygen mixture.
The idea around which developed the project, was to vent outside a small part of the mix and replace it with "fresh" provided by the automatic demand valve. The first version this rebreather employed a small bag lung, 3 lt, so the volume of gas expired, certainly more of the 3 lt, was vented outside, but the volume of gas expired depended by the volume of the breath and this made very variable the ratio of gas vented to recycled (venting ratio) .... and so also the FO2.

Picture: MIXGERS 1972

DC 55 rebreather GERS

The GERS (Groupe d'Etudes et de Recherches Sous-Marines) went to examine the construction of a system where the ratio of the vented volume to evolume ventilated and ejected was constant, (regardless of the "depth" of breathing). In 1949 tests at sea confirmed its validity:the passive addiction rebreather was born. The prototype, which had the initials of DC49, said following a family of devices whose validity is still valued today: the DC 55, last of the series is still in use in the French Navy.
There are many rebreathers, such as Halcyon 80, which still employ this principle of operation.

Picture: GERS DC55 1955


salvus siebe gorman

Siebe Gorman in 1942 produced "Salvus", an oxygen rebreather for rescue and short dives.



That same year, Hans Hass, the first "modern"underwater photographer , which took his photos free diving or sometimes with a helmet fed from the surface, needed a self-contained breathing apparatus. Then he asked to Dräger of Luebeck to modify the equipment for rescue by U-Boot, accepting his demands, the company realized in that way an oxygen rebreather: Hans Hass was also the first underwater sports researcher to use this kind of rig.


In USA during WWII, DESCO, builder of the famous Diving Helmet MK V, received a large contract from the Navy in what was including the production of an oxygen rebreather, the "B -Lung" (Browne Lung-the name of Jack Browne) which will be then used in warfare, salvages, underwater work construction and demolition. After the war, the fame of B-Lung find continuity at the hands of Colonel John D. Craig, with whom realize the photos of his book "The danger is my job."



After the WWII another great revolution is achieved in the field of scuba equipment: To overcome the limit depth of the oxygen, Cousteau-Gagnan develop the demand valve, the heart of the open circuit: with its simplicity and relative safety, it will open the doors of the underwater world at whole mankind.

However, the oxygen rebreather is not abandoned. The first underwater movies, by Hans Hass to Folco Quilici were made just with oxygen rebreathers: the absence of bubbles and the silence, together with the simplicity and lightness are still valid arguments, so that its developments did never stop and new models are continuously made.
Even today you can see the difference between Cousteau' movies who used open circuit and Hass who was using an oxygen rebreather: sharks movies from the first show nervous behavior, instead in Hans Hass' movies the natural movements highlights the beauty of this predator.

Photo: underwater shots of the film Folco Quilici: "Tikoyo and his shark." At left Folco Quilici and right Masino Manunza



Particularly effective was the educational use, by italian training agencies, of the oxygen rebreather from the first dive schools as preparatory to open the circuit.

Photo: Oxygen rebreather traininm for open circuit courses. Italy, years '60


IDA 57 oxygen rebreather

Meanwhile in Russia was experimented different solutions.
After the IDA 57, an oxygen rebreather with a metered nozzle that enable it operate also as a semi-circuit rebreather, was made an apparatus for the exit from submarines up to 300 meters deep IDA 59.

This picture shows the IDA 57

IDA 71 rebreather

The real news, however, is formed by equipment IDA 64, oxygen and, subsequently, the IDA 71, oxygen and Nitrox, where the oxygen consumed by metabolism is supplied by a chemical, a superoxide, which shall give amount proportional to carbon dioxide absorbed
Theapparatus is provided with two scrubbers: one for the soda lime and one for the superoxyde. A cylinder of oxygen is present in every way to restore the volume of the counterlung.
In this way the percentage of oxygen is chemically controlled. This superoxide is however dangerous to handle and harmful to breathe since stabilized with asbestos.


The picture shows the IDA 71

Dräger FGT 1-D scr rebreather In 1969, the Dräger, strengthened by more than 50 years experience in systems design SCR-CMF, produces the model FGT 1-D. This SCR born to be used in EOD ( Explosive Ordnance Diposal) operations. The silence of the SCR, due to low emission emission of bubbles, is an essential feature to operate near this type of weapons.
The Dräger has also produced special SCR selfmixing systems, like SMS or M100M and the model FGG III designed for bailout to allow the return in the "diving bell" for technical divers who work in saturation.

In the second half of the 90s the Dräger design a SCR system dedicated to recreational divers: the Atlantis.
This system, called then "Dolphin," is the first serious attempt to make use of these systems to the civilian market. For decades the rebreathers were almost the exclusive prerogative of the military.
The spread of the Dolphin was far below expectations because of the high price and use limited to 40 metersno deco stop dives.
A second attempt was made with the "Ray". This rebreather was designed for use with EAN 50, which it limited the use within 22 meters deep, perfect features for diving in tropical seas, but the cost and the need for specific training constituted a serious obstacle to its spread. The Ray was also fitted with nozzles that allow the use of EAN 40 and EAN 32, but with this didn't resolve the fundamental problems: cost and training. This level of commitment could be addressed by "technical divers", but would have required equipment operating with much greater depth.
In the picture: at left the Dolphin aand right the RAY

Azimuth SCR rebreather
During the same period the Italian O.M.G. develop a new SCR system: the Azimuth.
The O. M.G. has more than thirty years experience in military oxygen rebreathers design. The cooperation with the passionate designer Nanni Neuhold, brings innovative solutions than the Dolphin.
The Azimuth allows the use of any type of EAN and has a second cylinder that serves as both reserves than "bailout" in CA.
To meet the needs of the technical divers OMG designs the model Azimuth AF (Alto Fondale -that means Deep Diving into italian). This Rebreather has a Nitrox cylinder and a Trimix one, double-flow system and double bailout. It is the only SCR-CMF specifically designed for trimix diving.

fieno scr rebreather In 1993 Japanese Grand Bleu inc. " presents "FIENO."
This Rebreather stems from an ambitious project, strong technical and support by "Nissan": producing a SCR in an industrial scale for the recreational market. The FIENO works with EAN 40 with a maximum operating depth of 30 meters, autonomy is about 50 minutes with a cylinder just 1.5 lt through a system of oxygen supply that mix both active and passive addiction. The automatic DSV is revolutionary: it can be used as a normal two stage regulator. Not least the design, entrusted to the famous architect Masayuki Kurokawa.
The spread of FIENO is limited by the size of bags that seem to think lung exclusively for divers and small stature.
Again, the price (then U.S. $ 3700) and the market, oriented more to the "touristic diver" than recreational one, does not allow any change of direction. The production of this little gem in was stopped in1996.



In 1968, Ed Link, a pioneer of saturation diving, was conducting tests with his minisub "Deep Diver".
The "Deep Diver" was not the usual sub designed for scientific purposes, was truly innovative: half which allowed the divers involved in diving at the top and bottom to fall out of avoiding lengthy decompression in the water, in practice behaved like a self-propelled hyperbaric chamber .
The divers who participated in the experiments were equipped with a helmet and umbilical "Kirby Morgan, which is the 'standard equipment for saturation diving. The consumption of gas needed, for diving and the pressurization of the submarine, was such that the "Deep Diver" was forced to tow the large spherical tanks. Nevertheless it was forced to restrict diving, which was necessary to face very high costs.

Photo: Walter Star

Electrolung rebreather

In the experiments were also two scientists, Walter Starck and John Kanwisher: the first was to run some samples of live to those depths, the second, physiologist, to perform measurements on heart rate and breathing.
The two immediately clear was the need to develop a system for breathing underwater that could ensure a more rational economy gas.
John Kanwisher, and physiologist, was also the inventor of polarigrafic oxygen sensor, so it was just the idea of a Self-mixing closed circuit capable of controlling the partial pressure of oxygen through sensors.
In six months the first prototype was ready, the Electrolung, was the first
closed circuit Rebreather in the history.

In the photo beside: the Electrolung


The spread dell'Electrolung in "civil" market was stopped by three accidents resulting from the lack of an appropriate training. Anyway the Electrolung did works fine and was used successfully used by appropriately trained divers, diving for military and scientific purposes, despite this, in most people remained the conviction that the responsibility was to be attributed to the rebreather.

MK 15x rebreather

In 1970 Biomarine produce the CCR1000, which, later known as MK 15 MK15.5 and 16, were adopted by the USNavy (the MK16 is still in use).
Who remembers this news in the diving magazines of that years will certainly has alive in the memory how the rebreathers seemed to be a far future and how long seemed distant the day that would be within the reach of many.

CIS lunar MK 5 rebreather

From Birth Electrolung is so long, the rebreathers and users
have evolved through the development of education. For instance, the first incident occurred with the Eletrolung, due to confusion between oxygen and diluent led the manufacturer to install a safety by-pass oxygen. Today as a mistake is not even taken into account, there is no security on by pass the new machinery.
The evolutionary path of Rebreather winds through some projects that represent real milestones. One of these is the "CIS Lunar MK 5", designed by Dr. Bill Stone in 1998



The Cis Lunar was a great protagonist of caving expedition in Wakulla Springs and was the Rebreather that has enabled the famous biologist Richard Pyle to discover new life forms in the deepest zone of tropical coral reefs, in some far places, from a logistical point of wiew the use of the open circuit was impossible. The Cis Lunar was a too expensive rebreather for most users and in any case left CCR diving prerogative of military and scientific divers.


Over the same years was developed from an idea by Dave Thompson on the first CCR that could be within reach of many divers: the Inspiration. This Rebreather, which was also the first to be certified CE, was sold in thousands of units: affordability through facilitating constructive and investment for the molds needed to produce the various components with a certain economy, has finally paved the way immersion in closed circuit divers to "recreational".


The Inspiration has also put to the test the education and has highlighted, unfortunately with many accidents, that the mentality and training required to use Rebreathers are much more critical than the open circuit.


The development dell'ispiration is continued through the "Ambient Pressure Diving" by Martin Parker, who has also developed models and Evolution Vision. Ambient Pressure Diving facility is wel organized with very expensive devices for rebreathers' testing.


In 1999, Leon Scamahorn notes the "Innerspace System", which operated in the area since 1970, and form the "Innerspace System Corporation.
The "Megalodon" comes from some decade of experience in rebreathers' field. The philosophy behind this machine leads to a robust and high quality, made without compromise.
After several versions of the Megalodon Innerspace has also realized the Rebreather MCCR "COPIS"

Kevin Gurr, already known for having created the famous computer VR3 and VR2, began using the CCR in 1980, with his qualification of electronics engineer, works with a company engaged in the development of new electronic equipment for the JRC MK15.5 .
The experience led Kevin Gurr using different types of rebreathers and draw up a list of good things and those to avoid. Unfortunately, he could draw up another list, one of the incidents and causes. As such, it is materialized in a specific project, the Ouroboros CCR.