The first double hose?

[Akimbo]

Perhaps incorrectly, I recall hearing that the original regulator built by Émile Gagnan for Cousteau was a single stage and it was not until the mid 1950s that the two-stage double-hose came out. Does anyone have the details on this and if it is correct?

Interesting info
Émile Gagnan - Wikipedia, the free encyclopedia

 

[oldmossback]

As I understand the history, and if I am incorrect somebody will correct me.......the first reg by Gagnan and JC was a single stage, single hose that exhausted from the mouth piece......this didn't work so well and an additional hose was added to exhaust in the back like todays doublehoses.........

 

[Akimbo]

As I understand the history, and if I am incorrect somebody will correct me.......the first reg by Gagnan and JC was a single stage, single hose that exhausted from the mouth piece......this didn't work so well and an additional hose was added to exhaust in the back like todays doublehoses.........

Interesting. It is easy to see how a non-diving engineer might not consider the necessity for balancing the pressure across the diaphragm until analyzing the failure -- what the heck, it worked fine in the shop before you got it wet!

It would also be interesting to know about the development of the first two-stage single hose with the second stage at the mouthpiece. I didn't realize until Google'ing Gagnan today that he continued to work on diving regulators after moving to Canada (assuming that information is correct).

 

[captain]

The first regulator Gagnan designed used a two stage regulator Gagnan had designed to fuel engines with compressed natural gas because of the shortage of gasoline during the war.
The first attempt to dive with it resulted in a free flow in some positions but it worked perfectly in other positions. The secret to work in all positions was to relocate the exhaust valve from the mouthpiece to as close as possible to the diaphragm which required a second hose going back to the regulator which is the main point of Gagnan's patent.
The single stage didn't make the scene until the late 1940's..

Gagnan developed a single hose while in Canada but the powers that be didn't want to invest in developing it for sale, they felt the two hose was the premier regulator.

 

[Luis H]

The single stage regulator was not introduced until the early 50’s.

The first regulator was called the Gasone (the one that Captain is describing) and yes in the first try it didn’t have an exhaust hose. The two stages were mounted on the tank, but the first stage looked kind of similar to a commercial pressure reducing regulator, like an oxygen regulator on a welding tank (because that is kind of what it was).

The second regulator was a rectangular regulator with the housing made of Bakelite. It was never marketed.

By 1945 they came out with the CG45 (named for Cousteau Gagnan 1945). It was the first commercially available regulator. It has the now very familiar alarm clock shape of most double hose regulators and it was a two stage. All the early “Aqua Lungs” (the “Trademark”, the Navy DA, basically all the Broxton Ave. regulators) were direct descendants of the CG45, basically the same two stage design.


I can, kind of, understand how a casual observer would jump to the conclusion that the single stage design was around first, but how this miss-information has made it all the way to some books (like PADI manuals, etc.) is IMHO inexcusable.

I realize that as an engineer I have a special interest in understanding the evolution of technology, but as a diver I also feel that knowing the history of our sport is interesting and helpful.


Note: the venturi flow effect was first introduced with the single stage regulator.

 

[simonbeans]

These two excerpts come from papers written for and available at Vintage Double Hose.com

In the early 1950s, Emile Gagnan and his assistant worked to eliminate the two step pressure reduction system that had been in use since commercial production of the CG45 in 1946. He developed a regulator that reduced tank pressure to ambient in a single stage. The simplification to one stage led to a significant reduction in the number of parts and a consequent lowering of the cost of manufacture. 1 This system was based on a venturi system that was triggered by the diver’s initial inhalation effort and resulted in a powerful free-flow of air; a flow that would stop with any back pressure, like starting to exhale. He was granted a patent in 1955 for “Open Circuit Breathing Apparatus.” This patent resulted in a series of regulators. They were the DX Over-Pressure (1955-1957), the DW Stream Air (1956-57), the Jet Air (two models, DY brown or black phenolic, 1956-57 and the 1020 black cycolac 1961-63), the 1008 Mistral DW (1958-70), and the 1054 Royal Mistral (1965-67).

When Jacques Cousteau and Emile Gagnan collaborated in the development of the original Aqua Lung in 1942-43, Gagnan was never satisfied with the performance of the invention. With the success of the CG45, Gagnan continued to innovate, devising a way to combine a sufficient volume of air at any depth of the two stage unit with the low breathing resistance of the venturi-assisted single stage. Unfortunately, the single stage units with a smaller orifice, i.e., Over-Pressure, Stream Air, Mistral, Jet Airs, didn't provide enough air in deep water. The CG45 and later followed by the Broxton styles and finally ending with the DA Navy-Approved unit required relatively high breathing effort. In mid-1957, Gagnan produced a prototype and a short run of a new regulator that was to be called the ‘Aqua-Master.’ This regulator added a venturi-assist to the second, 'demand' stage.

 

[oldmossback]

The single stage regulator was not introduced until the early 50’s.




I can, kind of, understand how a casual observer would jump to the conclusion that the single stage design was around first, but how this miss-information has made it all the way to some books (like PADI manuals, etc.) is IMHO inexcusable.

Besides PADI, there are two other books, which I have that tell this tale incorrectly according to Luis.........it just shows ya can't trust nothing now days.......

At least I was correct about the exhausting from the mouthpiece......

 

[Akimbo]

So, the motivation for the single-stage double hose was production cost? Now that I think about it, there was about a 40% difference at retail, at least during the early 1960s.

The thing that made me suspicious of the single-stage first prototype story was the idea that the valve evolved from a regulator for a low-pressure supply. I appreciate that parts for prototypes are borrowed rather than tooled. It didn't make sense to me that the original design could be modified into something that could handle high pressure, which was probably in the 130 Bar range at that time.

Does anyone know if Cousteau had a relationship with Air Liquide before the Gagnan collaboration or did it come after? I was always surprised that Cousteau didn't go into the trials and tribulations of development in much detail (at least that I could find). It had to be a really interesting story considering the Nazi occupation and all the parts were high-value war materials.

 

[elmer fudd]

My understanding is that the first regulators were two stage regs and that single stage regs were developed in the mid 50's because they were simpler, cheaper and more rugged than their 2 stage counterparts.

My guess is that they died out earlier because they can't supply low pressure ports. A two stage reg could run a BC, drysuit and an octopus off the hookah port, but a single stage reg just didn't have that capability. Then again, the two stage regs had also mostly died out before those things became universal.

 

[Luis H]

Does anyone know if Cousteau had a relationship with Air Liquide before the Gagnan collaboration or did it come after? I was always surprised that Cousteau didn’t go into the trials and tribulations of development in much detail (at least that I could find). It had to be a really interesting story considering the Nazi occupation and all the parts were high-value war materials.

I don’t know the details, but what I have read is that Cousteau’s wife, Simone, was the daughter of one of Air Liquid top managers. Cousteau had no interest on the development of the regulator; he was interested in using it for his underwater film making and exploration, etc.

Simone father was who put JYC in contact with Emile Gagnan.

You can see a lot of Cousteau equipment in Flashbackscuba.com. Cousteau had no attachment to any piece of equipment; they were just tools to him. There is a great article about Cousteau on this month Historical Diving Society magazine by Ryan Spence (the owner, collector, and now historian behind FlashbackScuba.com).


Oldmossback
These statements are not just “according to Luis”. There is substantial physical evidence, drawings and write ups from Emile Gagnan himself, articles in the Historical Diving Society (from Phil Nuytten and others), and lots of hardware pictures to back my statements.

There are plenty of examples of the CG45. I also have pictures of the Bakelite rectangular regulator and you can see pictures of the Gasone in the Historical Diving Society magazine.


Added:
In God we trust… everyone else, please bring data/ hard evidence.