Legends of Diving Articles


Ted Eldred
First Commercially Successful Single Hose Regulator

Ted Eldred

Ted Eldred was born in Melbourne, Australia on December 20, 1920. Having grown up by the sea, he spent much of his time as a young boy at the beach and swimming in the waters around his home of Sorrento on the Mornington Peninsula, south of Melbourne. Ted started snorkeling and spear fishing as soon as mask and fins became available, and this early experience would later help in the equipment design he would later become known for.

While Ted was still young, a terrible storm came through the area and sunk a lot of small crafts and caused a lot of the other boats to be swept away into shipping channels and deeper waters. The young man was fascinated by a local garage proprietor who had a barge fitted with a winch and who had developed a technique to salvage the boats by dredging them off the bottom and moving them into shallow water where they could be coupled to a tow truck and pulled clear of the water on a roller. Ted would dive down and attach the winch rope to the craft so the wrecker could pull them out. He had no equipment to assist him and the job became much more difficult and dangerous as he progressed into the winter season and experienced colder conditions, stronger currents, deeper waters, and decreased visibility.

It was during this period that Ted began to develop techniques that would later provide a practical foundation for the development of equipment. For instance, he learned to use goggles filled with fresh water to fill the space between the glass and eyes to prevent mask squeeze. To combat the cold he would wear close fitting Ted, Batterham, Bob Wallace-Mitchell
(Early 50s)
woolen clothing and developed techniques of muscle relaxing to enable the maximum workload to be conducted with minimum effort. Ted utilized hand-held weights attached to a light line to descend to the bottom quickly and learned to hyperventilate prior to diving to decrease the carbon dioxide tension. He would expel small amounts of air during his ascent to achieve the same effect.

After graduating from school in the mid 1930's, Ted soon discovered his first love, the field of engineering. Ted's training covered a five year period and during this time he was employed in the design and manufacturing of production tooling. While working, he took a night course which carried into the war years. Eldred was in charge of an extensive tool room engaged in both experimental and production activities for the Armed Forces during the Second World War.

Ted had ties with the medical profession and had his first oxygen rebreather built by 1946. It was during this period from 1945-1947 that he became involved in designing two rebreathers and was involved in testing trials. Eldred was able to explore the limitations of diver and equipment, coming to the conclusion that "in a near death situation, when respiration became uncontrollable it was helpful to be breathing oxygen."

He shared these rebreathers with his friends, Dr. Bill Taylor being one of them. Ted and Bill would dive together on weekends, using his underwater breathing apparatus that already bore the name "Porpoise." Oxygen rebreathers can be fatal below 30 feet, as the increased pressure makes oxygen poisonous. During one of Ted's rebreather demonstration at Flinders Pie, South of Melbourne, a diver passed out because he failed to purge the system of air. Failure to purge results in anoxia. As the diver metabolizes the oxygen and the scrubber absorbs the resultant carbon dioxide, only nitrogen is left. Ted determined that his efforts should be directed toward developing an open circuit compressed air breathing apparatus.

At this stage Eldred had established his own business specializing in aluminum die casting of high tensile nonferrous alloys and was the first to pressure cast magnesium alloys in Australia. This enabled him to manufacture the Porpoise gear.

During 1948 to 1950, further development of the rebreathers was severely restricted due to the lack of knowledge of Ted with his grandson in the famous pool in which he had taught. This was his last dive at 80 years with his invention. underwater respiratory physiology by the medical profession. Ted was advised to contact the Navy, with the object of seeking permission to study the work being done on diving rebreathers in England by the Royal Navy and Siebe Gorman Company.

Eldred met Commander Maurice Batterham, one of the most experienced clearance divers with over 2,000 hours of wartime experience to his credit. He had been recently appointed assistant director of underwater weapons for the RAN (Royal Australian Navy) and was able to assist Ted in furthering his studies. The commander expressed an avid interest in Eldred's work, offering him assistance and advice, which helped Eldred greatly.

Having gained access to Royal Navy medical files extending back Ted wearing the Porpoise. some 15 to 20 years, Ted was able to enhance his already extensive knowledge of respiratory requirements for underwater application. The two rebreathers he had already developed had, by that time, accumulated hundreds of hours of usage and continued operating successfully for training purposes for many years. Eldred gained an excellent reputation in the field and was in great demand to demonstrate and lecture on underwater respiratory physiology at that time.

Jacques Cousteau and Air Liquide's engineer, Emile Gagnan, had invented and marketed the double hose regulator, the CG 45, which was a demand regulator. The amazing thing is that today the modern sport diver uses Ted's ideas that were perfected as early as the late 1940's; the powerful air delivery source known as the single hose regulator.

Ted came to the conclusion that to survive underwater with an extreme stress load, a diver actually needed a demand regulator that would deliver 300 liters of air per minute. The Aqua Lung was delivering 140 liters of air per minute and many scoffed at Ted's proposal at the time he first voiced it. However, history has shown that Ted was indeed ahead of his time. Both the British and Australian Navy accepted the 300 liter standard as their own. This value was also confirmed in the 1950's by the commercial diving industry, as well.

Ted finally came up with a totally different scuba regulator system by using one hose from the regulator mounted on the cylinder feeding the diver with his compressed air. This took several years to perfect and finally he called it the "Porpoise." During production he made several changes, including a vacuum assist, to deliver more air to the diver. It was at this time Commander Batterham was to retire and offered Ted his help to start a business. A young Ted and Bill Taylor in the late 40's wearing Ted's rebreather. In 1952 he aided Ted in starting the Breathing Appliance Company in Melbourne. The company mass produced the Porpoise single hose scuba gear. Eventually the Royal Australian Navy adopted the Porpoise for their divers. At this time the Porpoise Hookah units outworked the cumbersome helmet gear.

Ted, along with Batterham, Dr. Bill Taylor, and Bob Wallace Mitchell, set up Australia's first scuba school at the Melbourne City Baths in 1953. It was very successful and the classes were conducted two nights each week over a period of six weeks. Volunteer staff were trained to assist Batterham and Eldred and each student was individually trained to use and service both air and oxygen equipment. Each pupil underwent carbon dioxide and an anoxia test to familiarize themselves with their individual symptoms and finally sat for a written examination set to the RAN standards.

The school was in constant demand to provide demonstrations at swimming carnivals held in Victoria and the NSW and generated publicity and interest in diving. In 1954-55 diving activity in Australia became much more popular. Clubs were being formed and local manufacturers started to copy the Porpoise single hose design. In 1954 the Royal Australian Navy (RAN) expressed a keen interest in compressed air breathing apparatus (CABA) and set about compiling a set of detailed specifications for their requirements.

By 1954 the double hose regulator The first Porpoise. had been on the market in the US for a few years. The Green Label Aqua Lung was just being produced in the US. Ted's single hose had been in full production for two years. Australia never did receive the double hose regulators the rest of the world was using.

Overseas manufacturers Siebe Gorman, in the United Kingdom, Draeger in Germany, and Scott in the USA were all trying to compete for the Australian market but were outperformed in 1955, for the Porpoise dominated the Australian market. Between 1952 and 1975 there were over 12,000 Porpoises made and 75% of those were Hookah. At this time Aqualung was making and selling that many regulators in a month.

Australia produced the first single hose regulator as well as the second and third; Sea Bee in 1954 and Scubamatic in 1956. There was one regulator called the Lawson Lung which was chest mounted and was very hard breathing. There is only one Lawson Lung still in existence.

In 1956 Gregory Peck was in Melbourne with his co-star Ava Gardner filming "On the Beach." At this time neither Ted nor the rest of the world knew about each Ivor Howitt (left) and Ted, wearing Ted's rebreathers
(credit: Ivor Howitt)
other's inventions. Venture capital was impossible to get at this time and Eldred's company struggled without capital assistance. Importing German made cylinders was very difficult at this time, making their situation even more difficult.

While diving on the Great Barrier Reef in the late 1950's, the famous writer Arthur C. Clarke used the Porpoise gear and that drew the attention of the Air Liquide Company, which owned the patent on Cousteau's Aqua Lung. There were many inventors around the world who claimed to invent the single hose regulator. None delivered the 300 liters under stress that the Porpoise did. Hearing of the news, Air Liquide sent representatives of La Spiro Technique to Australia to inspect the Porpoise themselves.

They were amazed at what they saw. Ted was definitely ahead of them and was a real threat to the Aqua Lung. They wasted no time flexing their muscles. In 1960 Aqua Lung told Ted they wanted to buy him out. If he would not sell they threatened to flood the market with cheap Aqualungs and put him out of business. Ted sold the company to them for just enough to pay off his debts and walked away with nothing. For Porpoise logo decal 18 months he worked for the new company before freelancing. Asked if he regretted selling his company, he said "I'm an engineer, not a bloody salesman." He added, "I suppose it's nice to realize that you led the world for a period of time, and I was way out there in front." Cousteau's double hose was phased out in the 1960's but some 60 years later, Eldred's invention of the single hose is still in use. The Historical Diving Society South-East Asia Pacific officially recognized Ted as the inventor of the first commercially successful single hose regulator and named an award after him.

After selling his company, Eldred was a consultant to Normalair Garret, who manufactured breathing apparatus for firemen and industrial applications. Ted then worked on the Concorde Aircraft and the air conditioning feature of that aircraft. He was a very talented engineer and left his mark on the world. Ted passed away on the 26th of August 2005. Before he died, his son had him enter the pool at the scuba school he had established to demonstrate for his grandson the Porpoise, the first single hose regulator ever produced. Porpoise regulators are very rare and it is estimated that there are only 65 of them left in private collections today.

(ILD would like to thank Steven Taylor, Des Williams, and Tony Eldred for pictures and biographical content)

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