Check this vintage ad out...

[Luis H]

Kids have an excuse at least : haven't studied physics yet. But what about the engineers who designed that rig ?

Yeah, but as an engineer myself, I like to restrain (a little bit) on criticizing what we did in the past. It is very easy with the information we have gained with time to look back and wonder... "what were they thinking?".

Then again, these were German engineers... "what were they thinking?" ... They have a reputation for doing better than that... Just kidding...
I know they are your neighbors... we should not criticize your neighbors.

.

 

[CT-Rich]

Yeah, you need to use deeper breaths, which is not a bad idea in general for diving to flush CO2.

The volume of a single (ambient pressure) one inch hose (20 inches long) is about 16 inches cubed (or 257 ml). The volume of the can is about 200 ml (a calculated approximation). For a total of about 457 ml (can and hose).

Per Wikipedia:

“Tidal volume (symbol VT or TV) is the volume of air moved into or out of the lungs during a normal breath. In a healthy, young human adult, tidal volume is approximately 500 ml per inspiration or 7 ml/kg of body mass.”

That assumes a 71kg person or 156 pounds.


So, if you do take deep breaths, you would flush must of your expired CO2 out, but not all of it.


I would multiply the numbers on the vertical scale by about 80 kg (for a 176 pound person). Adjust it as needed.


View attachment 755549

She does not look to be 156 lbs

 

[Luis H]

Good point.

 

[Jeff_O]

Most of the fresh air from the tank is getting pushed out the exhaust, while the stale air gets recycled. It’s kind of amazing that they thought this was a good design at any time…

It’s like the kid that thinks a four foot garden hose will make a good snorkel.

I tried using a snorkel when maybe 7 years old and found that if I very carefully kept the snorkel top opening just inches from the kiddie pool surface, I couldn't breath in any air at all. Later at 21 certified scuba, I could clearly see how conversely holding ones breath is a no no. Not that I ever tried though. A first stage is quite a marvel coupled with demand valve. I have had to explain how on scuba, to non-scuba divers, you don't feel the pressure on your chest as breath hold skin diving does. Static pressure is there I know, but you would not really to know at sport diving depths. Well my idea of extending a snorkel with hose to get to 2 foot depth kiddie pool was thwarted even before it got started with that test.

 

[АлександрД]

Up periscopes to admire Jaqueline Bissets Micro Piel regulators

View attachment 639003


Redirect Notice


Redirect Notice

Look what I came across anyone recognize?

And there was I thinking it was a early Mk 10, must look closer. I think MK10, based on the swivel cap.

scubaboard.com

But last picture is not Micro Piel, but full huge helmet

(from Les grandes vacances (film) - Wikipedia )

 

[АлександрД]

Diving is sexy…

View attachment 731051

 

[Bigbella]

Very nice -- either using a Poseidon Cyklon Junior; or, perhaps a Barakuda - Cyklomat, made by the same folks.

Sweet -- just kicking it with a single hose and a tank; SPGs were still a few years off . . .

 

[rx7diver]

Very nice -- either using a Poseidon Cyklon Junior; or, perhaps a Barakuda - Cyklomat, made by the same folks.

Sweet -- just kicking it with a single hose and a tank; SPGs were still a few years off . . .

Looks to me like she might be wearing doubles. There seems to be the yellow shoulder/crown of her right-hand cylinder barely visible.

rx7diver

 

[Bigbella]

Looks to me like she might be wearing doubles. There seems to be the yellow shoulder/crown of her right-hand cylinder barely visible.

rx7diver

Looks like you're correct -- could even be sporting one of the early manifolds . . .

 

[CT-Rich]

Very nice -- either using a Poseidon Cyklon Junior; or, perhaps a Barakuda - Cyklomat, made by the same folks.

Sweet -- just kicking it with a single hose and a tank; SPGs were still a few years off . . .

In addition, laws protecting antiquities were also still a bit off in the future…