Redundancy with a Single Tank

[Arcaporale]

There shouldn't be a need for redundancy of this sort because you shouldn't be going into deco or an overhead environment with a single tank, which means if a regulator where to fail, which is very rare, you end the dive and make a safe accent with the gas that remains, not switch to your redundant source and continue. Let me elaborate, if you primary 2nd stage fails, switch to your backup or octo. and end the dive. If you 1st stage fails, it is likely to cause a freeflow, not stop the the air from flowing. You would then just continue to breathe from the freeflowing reg and make a safe accent.
People have this tendency to think that more is better, sometimes it is, but in this case a second reg only add the amount of potential failure points on your rig, thus making it more likely a failure will occur. If you need this kind of redundancy then you should also have redundant gas which means doubles with an isolator.

I've never seen any DIR or Hogarthian divers with a Y valve. If a Y valve was DIR then don't you think Halcyon would make one?

 

[rjack321]

Why, here in the hogarthian "minimalist" forum is everyone always talking about redundancy??

Put the pony threads somewhere else please, those things are anything but minimalist.

Your redundancy with a single tank is on your buddies back. Just like it is when diving doubles in an overhead.

 

[OneBrightGator]

There shouldn't be a need for redundancy of this sort because you shouldn't be going into deco or an overhead environment with a single tank, which means if a regulator where to fail, which is very rare, you end the dive and make a safe accent with the gas that remains, not switch to your redundant source and continue. Let me elaborate, if you primary 2nd stage fails, switch to your backup or octo. and end the dive. If you 1st stage fails, it is likely to cause a freeflow, not stop the the air from flowing. You would then just continue to breathe from the freeflowing reg and make a safe accent.
People have this tendency to think that more is better, sometimes it is, but in this case a second reg only add the amount of potential failure points on your rig, thus making it more likely a failure will occur. If you need this kind of redundancy then you should also have redundant gas which means doubles with an isolator.

I've never seen any DIR or Hogarthian divers with a Y valve. If a Y valve was DIR then don't you think Halcyon would make one?

FYI for everyone, this thread is 2.5 years old.

You obviously have no idea what you are talking about since most Introduction to Cave Diving classes are taught with students using single tanks with H or Y valves.

As discussed earlier, an H or Y valve is ideal for most ice diving.

I have seen plenty of Hogarthian divers using H-valves, myself included.

 

[Nemrod]

It is just a question, what is the consensus for using stages with a single tank rig. Well, OK, somebody has a pumped up 120 that is stuffed to 150 cf. More than some smaller doubles rigs, maybe they could justify a stage with their single?
N