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INVENTION OF THE AQUA LUNG
DEFINING EVENT: COUSTEAU STANDS ON HIS HEAD
It took an ambitious diver and a valve engineer to finally come up with the "perfect" recreational diving system. They were Frenchmen, Jacques-Yves Cousteau and Emile Gagnan.
Cousteau had been the leader of a trio of pioneer skin divers-together from 1936 on. He was the more polished spokesman of the talented trio and the other two, Frederic Dumas and Phillipe Tailliez, let him assume the public image role. They all had the dream of breath-holding divers to be able to stay down and observe life there for an extended period of time.
It meant improving what breathing systems had been invented to this point to enable the swimming diver. Cousteau took his ideas and those of LePrieur and others to a Emile Gagnan, an engineer with a commercial gas company, Air Liquide. Conscripted to do underwater work in Toulon Harbor where the French fleet had been scuttled to avoid capture, Cousteau's team had the opportunity to try diving systems. The outshoot of it was the realization that apparatus existed to provide diving free from surface air if there was some way to control the compressed air so it would flow to the diver only as needed.
PRECURSORS TO THE AQUA LUNG
There were many precursors to the Aqua Lung. But the history leading up to a self-contained breathing apparatus is filled with other discoveries that paved the way.
There are myths and fantasy stories galore. The ancient Sumerians of 5000 BC had a king who tied rocks to his feet and breathing surface air through a tube of seaweed, searched for a plant to provide eternal life. Aristotle told of Alexander the Great using underwater breathing apparatus in the form of diving bells. Leonardo Da Vinci had lots of drawings of undersea breathing devices.
A major guideline for inventors of the past century and a half was Jules Verne's 20,000 Leagues Under The Sea which imagined much of the diving equipment used by modern diving. Cousteau said, ..." Like many poets, Verne led the way for science to follow." Augustus Siebe in England, about this same time, actually created a lot of this dreamed-up equipment.
Probably, the most influencing development leading to the Aqua Lung, the self-contained underwater breathing apparatus (S.C.U.B.A.) as it is referred to generically, was in 1865. A French Naval Lieutenant Auguste Denayrouse and a mining engineer Benoit Rouquayrol did produce a scuba unit but because air couldn't yet be compressed to adequate pressures, giant tanks were required. They gave it up and went back to air supplied from a surface hose.
The dreaded decompression sickness, the bends, showed up as divers went deeper and stayed longer, and it got great attention as workers in pressurized shafts worked underwater to put in bridge pilings.
Another Frenchman, Paul Bert, showed up in 1878 to explain how the body couldn't exhaust waste product fast enough and nitrogen bubbles would form in the blood stream to block circulation. A Scottish medical doctor, John Haldane, developed the first decompression tables for the Royal Navy which guided divers in interval ascents to allow time for excess nitrogen to be naturally eliminated.
In 1878, Henry Fleuss came up with a self-contained regenerating breathing apparatus that used a caustic soda to purify exhaled carbon dioxide. This was a closed circuit system. By 1911, Sir Robert Davis of England streamlined the Fleuss unit into a light cylinder with increased oxygen pressure. But the closed circuit idea was extremely dangerous at depths below 30 feet where divers breathed nine times more oxygen than in air at normal pressure. Along came Frenchman, Yves LePrieur, who developed the first high-pressure cylinder using ordinary air and his regulating device patterned after the Rouquayrol-Denayrouse design. This device allowed exhalation to escape into water under the edge of the diver's mask, eliminating the recirculation of breathed air.
Cousteau and Emile Gagnan actually were diving with the LePrieur device in 1937. But the system seemed too complicated and would break down often.
Much credit must go to the many who experimented and invented before Cousteau and Gagnan.
TESTING THE IDEA
By summer of 1943, after six months of additional experimentation, the demand device worked effectively. By October 1943, it was put to an ultimate test by Frederic Dumas diving to 200 feet in open water off Marseilles for fifteen minutes.
It might have been snatched up by the military, French or Germans, except for the telltale bubbles of exhalation in an open circuit type scuba. Rebreathers were closed circuit and detection resistant. The "AQUA LUNG", as Cousteau's group decided to call it, was destined to be, it would seem, a grand new toy for civilian divers to use sight seeing and exploring. The Cousteau team used it for such purposes until the patented device went into the market place in 1946.
It was not a booming sales success at first in the European region probably because most people were a little afraid of the idea. But the Cousteau group kept pushing its potential with Dumas diving to 306.9 feet in August 1947. In September 1947, a French Navy officer reached a 397 feet depth record but surfaced unconscious and died a short time later. A limit seemed to be evident.
It would take the American market and American competitors with slightly different versions of the Aqua Lung to pressure the Company Air Liquide (on whose Board of Directors Cousteau's father-in-law sat) to increase production of this reliable and low cost breathing unit to meet the demands of sport diving in America.
IN PURSUIT OF COUSTEAU'S LIFETIME DREAM
Cousteau with this frustration of all the free diving pioneers in the 1930's tried his hand at inventing a breathing device. Even as an eleven year old. Taking a blueprint of a two-hundred ton floating crane, he proceeded to build an electric powered model with his Meccano Toy Building Set.
In 1938, while on Navy duty aboard a French Cruiser, Cousteau designed an oxygen rebreathing lung-built it out of a brass box and motorcycle innertube following the principle then being used to escape submarines (Momsen Lung). Misled by experts telling him oxygen was safe down to 45 feet, he over-did with his first closed circuit scuba and was fished out unconscious after a violent oxygen convulsion. A redesign and second attempt had the same result. Cousteau moved his thinking from the danger of oxygen to considering the helmet diving using compressed air to 200-feet, then being used by commercial and salvage divers. But he did not like the lack of freedom of suit, boots, helmet and lines.
World War II exploded and by November 1942, the Germans moved into Southern France. The French sunk their Navy fleet in the Mediterranean to keep it from the enemy. Lieutenant Cousteau was discharged. Cousteau then took on the development of a self-contained-air-lung full time. He had no idea that the great passport to innerspace, the Aqua Lung, would be born out of an automobile gadget.
Cousteau would be financed by Air Liquide, A French company, and there he would team up with Emile Gagnan. Gagnan, a retiring and shy man, was an engineering genius in the field of air pressure apparatus. He had designed a regulator to use cooking gas in autos instead of gasoline. It was many weeks before the two men realized what they were seeking to control air in a breathing apparatus was sitting out in the parking lot.
The redesign of the car gas regulator was not a simple crossover to underwater use. One chamber of the Aqua Lung would fill with water to aid the flow of air into a dry chamber to supply the diver. Air flow stops when the pressures become equal in wet and dry chambers and the diver's lungs. There was not instant success. Cousteau took the prototype into the dirty Marne River outside Paris in January 1943 with Gagnan watching from shore. Gagnan was elated to see bursts of bubbles and then alarmed to see the bubbles cease entirely. Sensing failure and Cousteau's demise, Gagnan threw off his coat and began untying his shoes. Cousteau appeared to explain, "I was standing on my head and it gets hard to breathe upside down and runs wide open standing up. It was okay when I was swimming horizontally. How can we go up and down?," he queried.
Dejected they drove back to Paris but they suddenly understood what had happened and began shouting at each other.
"The exhaust valve is six-inches higher than the air take on the back. It's the difference in the water pressure. The air flow is suppressed."
And so as in all inventions, a simple adjustment, placing the exhaust near the center of the regulator diaphragm turned the ultimate corner for this marvelous tool-toy.
Cousteau took the adjusted regulator back in the water and did flips and rolls and headstands with a steady supply of air. His head popped the surface and he cried to Gagnan, "That's it!" They then patented the adjusted device as the Aqua Lung.
The invention of the Aqua Lung sits atop a mountain of efforts over the centuries, to allow man to be like a fish. Ideally, every diver should have surgically implanted gills but that has remained an unattainable God-like miracle over the years. Looking back we see wonderful but limited devices carved and painted into ancient walls. Predominant is the diving bell, an open topped...
