Problem at Gilboa 4/21

[Divin'Papaw]

But you're back to thinking you can get your pony deployed in a chaotic shower of bubbles. Is this something you work on?

A good reality check might be to have you're buddy unexpectedly shut off your backgas and see how quickly you can get to the pony reg. The time to find out if you can do or not is in 20ft of water, not 100ft of water.

I keep seeing the common solutions being:

1. You need an adequate amount of redundancy to hand significant tank (such as an extruded valve o-ring) or 1st stage (such as free flow) issues and get you and your buddy to the surface in a safe manner.
2. Practice, practice, practice. Don't slap a tank on your back or sling one on your side, never use it and then plan to be able to miraculously deploy it when the caca hits the fan. It must be a response that does not require thought or analysis but is pure reaction honed by repeated practice.

Those are the key answers I see to issues like this. Pony vs. doubles is simply a matter of how much redundancy, where is it and how is it accessed. Both have pros and cons that need to be weighed. There is at least one diver on this board who dives triples. That's another option, just not a common one.

I'm really not trying to be a pain. I'm an analyst by nature and I'm trained to analyze problems, boil them down to their root cause, assess a set of possible solutions and select the best solution. In some scenarios, doubles are clearly the best solution to the problem. In others they are overkill. Then there are gray areas where you can make arguments both ways and you can have divers going in EITHER direction and doing it SAFELY. I'm trying to figure out where that gray area lies.

 

[adjuster-jd]

Aqualung sells a free-flow prevention device which goes in line before the second stage. Anyone have thoughts on whether this device would aid in stopping a free flow due to FIRST stage freeze up?

 

[ekewaka]

Aqualung sells a free-flow prevention device which goes in line before the second stage. Anyone have thoughts on whether this device would aid in stopping a free flow due to FIRST stage freeze up?

It will not stop the free flow. If you have it on one second stage, then it will just free flow out the other second stage. If you have the device on both second stages, then a hose will explode.

 

[wb416]

I keep seeing the common solutions being:

1. You need an adequate amount of redundancy to hand significant tank (such as an extruded valve o-ring) or 1st stage (such as free flow) issues and get you and your buddy to the surface in a safe manner.
2. Practice, practice, practice. Don't slap a tank on your back or sling one on your side, never use it and then plan to be able to miraculously deploy it when the caca hits the fan. It must be a response that does not require thought or analysis but is pure reaction honed by repeated practice.

Those are the key answers I see to issues like this. Pony vs. doubles is simply a matter of how much redundancy, where is it and how is it accessed. Both have pros and cons that need to be weighed. There is at least one diver on this board who dives triples. That's another option, just not a common one.

I'm really not trying to be a pain. I'm an analyst by nature and I'm trained to analyze problems, boil them down to their root cause, assess a set of possible solutions and select the best solution. In some scenarios, doubles are clearly the best solution to the problem. In others they are overkill. Then there are gray areas where you can make arguments both ways and you can have divers going in EITHER direction and doing it SAFELY. I'm trying to figure out where that gray area lies.

Sorry... I guess I AM starting to sound like a broken record. :14: This is more than I've had to say about anything here for a long time. Me thinks it's probably time to slip back into lurker mode again.

 

[ianr33]

If you have the device on both second stages, then a hose will explode.

Or even worse the wing will auto inflate leading to a ballistic ascent.

 

[Divin'Papaw]

Sorry... I guess I AM starting to sound like a broken record. :14: This is more than I've had to say about anything here for a long time. Me thinks it's probably time to slip back into lurker mode again.

I don't think so. You're just trying to get your point across and I appreciate it. NP!

 

[MikeFerrara]

Aqualung sells a free-flow prevention device which goes in line before the second stage. Anyone have thoughts on whether this device would aid in stopping a free flow due to FIRST stage freeze up?

If the first stage is what is free flowing, you'll have tank pressure (maybe 3000 psi) ervyplace. I agree with ekewaka.

I don't know for certain that the IP hose would burst...I've never tried it but applying tank pressure directly to a hose designed for 140 psi, can't be a good thing.

I think adding valves is a bad idea from a configuration stand point too.

 

[darylm74]

Sorry... I guess I AM starting to sound like a broken record. :14: This is more than I've had to say about anything here for a long time. Me thinks it's probably time to slip back into lurker mode again.

No way logie-mon. I think they are excellent points. I look back at the dive I did with Dave at that very spot in Gilboa back in March. So many things went wrong during that dive (free flow on the stage, leaking power inflator and I found out later that my gauge was actually about 250 psi high), yet things remained fairly calm and issues were resolved. That was my first free flow that I experienced personally, though I had seen it happen before on my AOW deep dive. The dive with Dave would have turned out a lot differently, in a bad way, had I been on a single AL80.

 

[maj75]

Would it be possible to regulate the pressure at the tank valve itself? Obviously, if you close the valve altogether, no air will "free flow". Could you shut the valve, do a controlled ascent and then crack it open when you need additional air?

 

[darylm74]

Would it be possible to regulate the pressure at the tank valve itself? Obviously, if you close the valve altogether, no air will "free flow". Could you shut the valve, do a controlled ascent and then crack it open when you need additional air?

Yes it is possible. I believe the process is called "feathering." Someone please correct me if I'm wrong. I ran through my last dive at Gilboa, where I expereinced a freeflow, with one of my mentors, and he described the procedure to me. He said that it takes patience and can be task loading, however it will work. He estimated that you use around 30% more gas with this process. He said the biggest issues were watching your bouyancy, remembering to blow bubbles as you ascended and not to panic. He strongly suggested that I practice it and I plan on it as soon as I can get back to a pool.