Connecting Sidemount Bottles With Hphose

[tbone1004]

there is also the crossover used in the RB80 and GUE modified JJ. That is basically the same isolator on a set of doubles but instead of the left side going straight into the valve, there is a HP hose that allows it to be somewhat flexible. All in all very annoying to use in sidemount and defeats much of the purpose of having truly independent gas sources.

 

[The Chairman]

I really don't see a benefit in reducing your redundancy and adding to your complexity. This seems to be one of those solutions in search of a problem.

 

[Coztick]

I am guessing that this is a theoretical question from a twinset bm diver...

I really don't see a benefit in reducing your redundancy and adding to your complexity.

All to avoid switching regs?
The problem is the complexity, failure points and inaccessibly in bm.
The solution is sm.

 

[kr2y5]

Do you see any advantage to a real manifold, as opposed to the UTD thing?

Real manifold, for sidemount diving? Nope

If you get a connection at valve level, you're able to balance your tanks, leaving both of them open at all time, having the gas in both of them available at any time, etc....

Sure, depending on your philosophy, I guess that can indeed be perceived as an advantage.

Or disadvantage.

AFAIK, for many people, having truly independent doubles is what makes sidemount safer, e.g., for solo diving. In other applications, the ability to independently manipulate and drop tanks seems to be important.

I don't know to what extent the Z-system retains every one of those advantages, or to what extent you can retain those or other advantages of sidemount with an HP connection like those posted earlier in the thread. I personally don't use the Z-system, but...

It just works better for me

I guess it's up to the OP to define what sorts of advantages / disadvantages he's looking for in the hypothetical configuration. Maybe a flexible HP manifold is the answer.

 

[cool_hardware52]

I'd suggest it's not about switching regs. Switching regs is trivial. BM doubles involves lots of reg / gas switches anyway. If you aren't comfortable switching regs SM and BM doubles are both bad ideas. For that matter diving may be the wrong recreational activity.

The key advantage to manifolded doubles is most failures, including the most common failures, allow access to *all the gas*. (There are of course a few, vanishingly rare failures, that can cause the loss of 1/2 the gas volume.) This advantage is achieved at the "expense" of more failure points, and more opportunities to screw up the management of a long list of possible failures, all of which are behind your head.

The advantage of independent SM bottles (no manifold) is far few failure points, and the diver can put eyes on the problem. This is achieved at the "expense" of single failure preventing access to 1/2 of the gas volume.

Pick your poison. Key to risk management is understanding the risks you are taking.

Tobin

 

[Patoux01]

I don't know to what extent the Z-system retains every one of those advantages, or to what extent you can retain those or other advantages of sidemount with an HP connection like those posted earlier in the thread. I personally don't use the Z-system, but...

Easy, that thing retains none of the advantages. You do not access all your gas in case of failure of one side. Even worse, it makes you close one valve at all time (not always the same, but you don't have both tanks on).

The only advantage of that manifold is that you don't change regs anymore...


The safety of sidemount does not come only from its independent setup, else there'd be little reason to use it instead of bm independent twins.

 

[lermontov]

I'd suggest it's not about switching regs. Switching regs is trivial. BM doubles involves lots of reg / gas switches anyway. If you aren't comfortable switching regs SM and BM doubles are both bad ideas. For that matter diving may be the wrong recreational activity.

The key advantage to manifolded doubles is most failures, including the most common failures, allow access to *all the gas*. (There are of course a few, vanishingly rare failures, that can cause the loss of 1/2 the gas volume.) This advantage is achieved at the "expense" of more failure points, and more opportunities to screw up the management of a long list of possible failures, all of which are behind your head.

The advantage of independent SM bottles (no manifold) is far few failure points, and the diver can put eyes on the problem. This is achieved at the "expense" of single failure preventing access to 1/2 of the gas volume.

Pick your poison. Key to risk management is understanding the risks you are taking.

Tobin

thanks tobin i think this pretty much sums it up

 

[PfcAJ]

IIRC, a "soft manifold" has been used in some rebreathers, but I think it didn't have an isolation valve.

Thusly.
Knobs on top are isolators, knobs on the sides are normal tank valve knobs like on a set of doubles.

I've also got a set with a modified normal manifold with a stainless swagelok pipe extension. Only one isolator, but I might add another at some point.

Wouldn't use any of this for SM though.

 

[Coztick]

The key advantage to manifolded doubles is most failures, including the most common failures, allow access to *all the gas*

I suppose this might be the difference between life and death in a cave.
If diving sm with a stage, couldn't a diver swap regs on bottles to access all gas in the same emergency? (Reg failure)
I'm wondering, if not packing a third bottle, do any of you crazy (most respect intended) SM cavers carry a backup reg set in case...? Swapping on one breath would be unnerving I would think.

 

[skippy31]

Yep. Unlike back mount with sidemount you have options. Bring more stages if you need more redundancy. Stages provide more gas, and more importantly more regulators. Pretty easy to diagnose a failure on your main tanks when you can see them. Shutting things down is also easy. Everything can be accessed should a failure occur so a "sidemount manifold" is a waste of time and equipment. Pretty simple when you can see all your gear...