First single hose scuba.....

[YankDownUnder]

The first single hose regulator, Ted Eldred's Porpoise began it's life as a rebreather. In this picture Ivor Howitt and Ted Eldred wear Porpoise rebreathers. These rebreathers were designed so the diver's oxygen would be restricted if he went too deep. However, Ted felt it was still too dangerous so he shifted his attention to an air system.


Ivor Howitt Picture




This picture was taken in about 1951 in Melbourne. It is the prototype of the Porpoise single hose scuba, which would become the first commercially successful modern scuba. The picture was taken at a pool complex called the Melbourne City Baths. Notice the diver is wearing a sweater. Wet suits had not yet come to Australia.



This is the first open water test dive of the Porpoise prototype. The first stage was an oxygen welding reduction valve. The picture was taken at Rickett's Point, Beaumaris, 10 mile south of Melbourne. Steve

[YankDownUnder]

This may be the rarest of the commercial scubas. It is a Porpoise CA-2. It was only made in 1953. What made it so rare was that it had two HP ports, each being a post that screwed into a tank valve. There was no manifold. Three are known and only one is in working condition. The Porpoise Universal was produced the following year, and used a manifold, which of course is a better idea. Steve

[YankDownUnder]

The Porpoise was a modular design which allowed it to be quickly converted from a scuba to a multi-tank hookah. It was very easy to change it from a single tank to a double tank as well. The military bought them in deployable wooden boxes. Australia had almost been invaded and students who attended the diving course were recorded for national emergency call up, but never were utilized.



This diagram is the second stage, which barely changed with the several models. It was called a mouthpiece regulator back then.



In 1954 the Porpoise reached it apex with the Universal reduction valve. It flowed 300 liters of air per minute. Combined with the venturi demand valve, potential buyers had to be warned as to how much air they might expect with a sudden inhalation.

Pictures from the private collection of the late inventor Mr. Ted Eldred, now owned by his son Tony.

Steve

[antique diver]

Steve, you always come up with the greatest old photos! Thanks for sharing them.

[DaleC]

Thank you Steve. Well presented and illustrated.

[YankDownUnder]

This is the last working Porpoise CA-2. It has twin 50 cu ft cylinders with a WP of 2750 psi. They are IWK German tanks and the joins are metal to metal. The demand valve is the left handed Porpoise, and the reduction valve is a diaphragm type, and unbalanced. This one was a little different because the diaphragm cover came off and was lost in a dive in 1954. It went back to the factory and there was only an un-chromed cap in stock as they no longer made that model, so that was installed. This one was bought by Ryan Sellars in 1953 and sold to me in in 2003. It had been test twice during it's working life, but never stamped. Steve

[YankDownUnder]

This 1953 photo was taken at the Melbourne City Baths. Standing is the man who set up the first diving school to use single hose scuba, Commander Maurice "Batts' Batterham RAN. He was a WWII frogman and cleared mines from the Thames after German bombings. The man in the tie is Australian actor 'Chips" Rafferty. He starred in Australia's first scuba film with actor Rod Taylor, who always played an American. It was called King of the Coral Sea. However, in that film they used the chest mounted Lawson Lung. http://www.youtube.com/watch?v=I1B_Y-FB3Es

The tank on the CA-1 was heavy and it had a quick dump canvas wrap instead of tank bands. The harness had a cork pad to protect the divers back, compensate for the tank's weight and give the diver some floatation when the tank was jettisoned. Diver's did not have wet suits yet, so heavy tanks were a problem. Bail-out was taught and divers were trained to dump an empty tank and free ascend.

What is interesting about Australian single hose scuba, was that it was developed without the inventor ever having seen the Aqua Lung. Therefor, everything was different. The tank was inverted because the diver had a regulator mounted reserve. With twin sets he could manage his air by decompressing. The valves were intended by the scuba inventor to be used upside down, but the valve makers did not intend that, so the valve stems were often bent by divers who didn't realize how easily they could be damaged. Steve

[Drado]

Those schematics are the best!

[YankDownUnder]

This is how the Porpoise was sold. It came in a school boy lunch box, with some tools, a pressure gauge, a boudon depth gauge and a nose clip.

[SDHR2010]

Hi all,

This a very nice piece of history (I got one too). But in order to be fair there is a debate about "The First" single hose. French first single hose "Cristal" by Mr Bronnec & Gautier or "Porpoise" by Mr Ted Eldred.

I have both in my collection but not sure about conclusion. What is the porpoise patent date?

regards

Franck

[YankDownUnder]

The Porpoise was designed in 1949. The first regulator was sold early in 1952. Ted Eldred said he could not afford to patent it, so he relied on improvements to stay ahead of others. The second model was the Universal which delivered 300 liters of air per minute and it came out in 1954. It was produced to compete with the Australian Sea Bee which also came out in 1954.

L'Air Liquide was so intimidated by the Porpoise Universal, that they purchased the small Australian company under threat of 'flooding the market' with Aqua Lungs at a low price. Reluctantly, Ted Eldred sold his company. Aqua Lung still holds the trade mark rights. The Australian company name was changed to Australian Divers Spiro, and became a part of the US Divers, Nihon Aqua Lung, Spirotechnique chain of companies. the last Porpoise Universal sold to the public was in 1976. They were only made for military service at that time. Only 12,000 Porpoises were ever made (1952-1976) and 75% of those were commercial hookah. The French made that many in a month. Steve

[YankDownUnder]

A link to the Legends website about Porpoise inventor Ted Eldred:

http://www.internationallegendsofdiving ... ed_bio.htm

[fizwhat]

Nice write up YankDownUnder.

I'll be picking up a CA1 set with two tanks at the end of this month and I was wondering what the most common problems were with restoring the CA1 to diving condition? The gentleman that I am purchasing from has informed me that the lp hose will need replacing. This presents a problem for me as I wouldn't know where to find anything like the original CIG comweld hose. Are there any spare parts available at all or good alteratives?

As for the tanks I grew up in Portland and know of Mr Zeigler so I'll probable take a little trip to see him.

If there's any helpful tips you can add please do.

Cheers,
Al.

P.S. I just realised you are the person that purchases the gentlemans other CA1 set .

[couv]

Very interesting. Thank you for sharing.