The latest technical diving regulator the Phoenix

[Gilldiver]

In this situation I will be carrying an 80 cu ft stage bottle with higher O2 than my bottom gas. Therefore, I am not planning on an extra bail out bottle.
.

An 80 Stage? You may be ready for some DIVING!

Come down here and do a few Subs with me next summer to work the kinks out and then we can add a bit of Helium and go see that "new" sub up in Casco Bay.

An 80 Stage of 32% and a 40 of 100% are what we use for the USS Monitor. So, you are half way there.

Pete

 

[Luis H]

It is what we are using in the class…and it just happen to be what I have.
I used it last weekend and it was fine.



I will eventually get some smaller cylinders, but the first pair of 40 I will probably join with a DIN manifold to make a sweet set of doubles. The good thing about the Drager DIN manifold is that I can separate the tanks since it just joins two DIN valves.

Too many projects.

 

[Nemrod]

Leaving aside the 80cf stage thing, a 19/30/40 balances well as a slung pony. I think I will stay with my fisherman knot and necklace bungee, it deploys fast and is secure. I have been diving this rig for sometime now and it is relatively easy to secure a 40 inch hose on the slung pony, in this case the pony second stage stays on the bottle, I do not secure it to myself. With this configuration there really is no reason to have a third second stage on the PRAM or RAM or for that matter on your back gas. We are not cave diving and we are not in overhead or are we? If we are then that changes everything or at least a lot. Now we have to supply full redundancy for our entire supply or at least for an amount as required by our planning to complete the dive and with our buddy on our air supply.

So, I guess I am confused as to what is the context of this discussion, what are we trying to accomplish?

N

 

[duckbill]

Ah, you have never been in the water with a panicked diver. They will not come up to you and politely say "Oh my, I am a bit short on air, would you mind giving me some?" - they take what you have as fast as they can.

Well, you are correct. I have never had to deal with a panicked diver, but that last part you describe is just what I would imagine it would be like. That is exactly the reason I said what I did. You wouldn't catch me giving a panicked diver a hose that was still around my neck. But, to each his own, I guess.

 

[Luis H]

We are not cave diving and we are not in overhead or are we? If we are then that changes everything or at least a lot. Now we have to supply full redundancy for our entire supply or at least for an amount as required by our planning to complete the dive and with our buddy on our air supply.

So, I guess I am confused as to what is the context of this discussion, what are we trying to accomplish?

N

The class I am in is deco procedures; therefore it is a “soft overhead’ environment.
The procedures we are covering are also intended to be the same for a “hard overhead” situation.

I don’t have any specific plans of where I am going with this; I am just exploring and gaining knowledge.

 

[Gilldiver]

Well, you are correct. I have never had to deal with a panicked diver, but that last part you describe is just what I would imagine it would be like. That is exactly the reason I said what I did. You wouldn't catch me giving a panicked diver a hose that was still around my neck. But, to each his own, I guess.

You missed the point I was trying to make - donating a reg from around your neck can be done, but why di it? There are much better ways such as a slung bottle.

 

[Nemrod]

If you use a long hose DIR style looped around behind your neck you will have to flip the double hose mouthpiece up to deploy the long hose. When you do so since we have no DSV the regulator will free flow wildly. I know this because two summers ago I experimented quite a bit with similar rigging. However, with a five foot hose, which would normally also be routed around and behind the neck, for our double hose tech rig we would instead tuck the loop under our weight/harness belt. The second stage would be bungeed at the neck on a fisherman knot so that a tug releases it for deployment to the OOA diver. (or clipped to rh D ring except for me that D ring is already awfully busy)

Since our rigs are non isolating and since the double hose has no DSV then having a second regulator for redundancy sharing the same air supply is dubious at best. For our purposes such as when I did a near 200 foot deco dive on the sunken bridge, I carried redundant air supply and deco gas in the form of slung bottles. My Sherwood manifold, like yours, does not isolate.

If we could reach back and turn either the double hose or the long hose second off and preserve our air supply with full isolation a different approach could be used but since we cannot certain aspects of the DIR rig are not practical to duplicate.

Since I tend to think in terms of solo rather than buddy/team it biases my thoughts. I just don't at this time like the idea of a long hose with a double hose regulator, it is a good way to share air but does not provide full redundancy. Like you, I am still experimenting and may change my mind about several things that are still jumbled up in my head.

N

 

[Luis H]

Since our rigs are non isolating and since the double hose has no DSV then having a second regulator for redundancy sharing the same air supply is dubious at best. For our purposes such as when I did a near 200 foot deco dive on the sunken bridge, I carried redundant air supply and deco gas in the form of slung bottles. My Sherwood manifold, like yours, does not isolate.

If we could reach back and turn either the double hose or the long hose second off and preserve our air supply with full isolation a different approach could be used but since we cannot certain aspects of the DIR rig are not practical to duplicate.


N

Our Sherwood valves will fully isolate any malfunctioning regulator. Whether it is the double hose or the single hose back up, I can reach and close that valve and totally isolate that malfunction.

The only malfunction I cannot isolate is a blown burst disk or a blown tank O-ring. As you know, I personally service my own valves and regulators and I am very conscious about potential failure modes…I guess you could say that I am willing to bet my life that a tank O-ring failure or a properly service burst disc is a reasonably insignificant risk.

The risk of a properly seated tank O-ring or a properly serviced burst disk failing is so remotely insignificant, that I am willing to take that minimal risk. I will of course share that information with any dive partner. IMHO, we are more at risk of being hit by lightning while on the dive trip.

Personally, I fill that an isolation valve adds more problems than it solves. IMHO, the design has a lot of room for improvement, but that will not happen as long as the general tech diving community continues to believe in them, in there present geometry.

I am keeping an open mind and trying to find out the value of the existing design, but I have yet to find a real need for it. If I was going to use a center isolation valve, IMHO, I would design it to be a quick acting 90 degree high reliability valve. Heck I would probably put all the valves on the bottom also, etc.


Note: I replace my burst discs on a regular basis and in the case of this doubles, I am using slightly higher pressure rated burst discs (just slightly higher).

 

[Nemrod]

We are looking at and discussing several issues at the same time:

Redundancy (solo or buddy)
Air sharing
Isolation capability
deco (overhead)

Which is why I was kind of confused and still am as I mentioned in my previou post. They are related but at the same time the have somewhat different means of accomplishing. The DIR system is one integrated solution to these multiple issues. What we are discussing (I assume) is what will be our solution to these issues?

Your comments as to the isolation, double hose irrespective, that is why I still like independent doubles.

N

 

[pescador775]

What about the miflex? Maybe the diver could coil the second into a pocket if a flexible hose was used. Use with one of those flat, alternate seconds. That's what they are for, presumably. The long hose is not the primary after all.