Goodbye ponies

[Doc]

If it's not an issue of transporting a tank on an airliner, then why not have a redundant system?

If you drag one through airport checked baggage, you have to pack it completely open and unplugged. It will be chilled to -20° for the air flight, then dumped on the tarmac in high heat and humidity. Now you can violate your redundancy standard or tank rules that require an inspection after that treatment.

Pick your poison.

 

[Web Monkey]

quit using the ponies and I have begun to rethink the desire for using the pony. I have been thinking a lot lately about air-delivery, failure modes, between the tank and my lungs. I have read that if one were to have a free flow, that one can fold the hose over and crimp it off. Somewhat like one does a garden hose.

I have heard that primary regulator failures (the one on top of the tank), under the conditions of which I dive, are practically unheard of.

You can still have all sorts of failures:

• Blown tank-neck o-ring
• Blown valve o-ring (inside the valve)
• Blown tank o-ring (between your reg and tank)
• Stuck-open first stage (ice, crud, crystalized salt, just broken)

I'm sure i'm missing a few.

However a good buddy and good gas planning is a perfect backup for all of these.

OTOH, if you don't dive with a known-good buddy (well trained and reliable, not just someone you like), you'll probably be safer with a pony.

Terry

 

[CamG]

Greetings Lee,
Your questions have been answered very well maybe not like you would have wished.
Failures can and do happen, most of the time we are prepared for them or should be!
I carry a redundant air supply "AL 30 on any dive over 60'"
I have used it a few times and it has been used for emergencies twice! Would everything have been ok without it? Maybe so, but maybe not!
I just feel the added assurance of having the extra capacity for self rescue and help of my buddy / other divers is worth the hassle.
It can be a pain to transport, but worth your life in a pinch!
Good luck and safe diving.
CamG Keep diving....keep training....keep learning!

 

[Darnold9999]

If it's not an issue of transporting a tank on an airliner, then why not have a redundant system?

If you drag one through airport checked baggage, you have to pack it completely open and unplugged. It will be chilled to -20° for the air flight, then dumped on the tarmac in high heat and humidity. Now you can violate your redundancy standard or tank rules that require an inspection after that treatment.

Pick your poison.

For this reason I pack my pony in a clear ziploc bag. If it survives the pressure drop in cargo it protects from the change in humidity. At least that's the theory.

 

[hobodiver]

Lee,

Why the desire not to use a pony? I ended up getting a 19 cu ft pony and slinging it, but I got the 19 precisely because I though a 30 was on the border of being too inconvenient of a size, and that I would start to decide against carrying it. So maybe the solution is to get a smaller pony?

 

[Hallmac]

Just because I'm bored I'll take the opposite side of the debate to keep things going.

I currently have 1,326 logged recreational dives. I have not experienced a single failure that required a back up, nor a buddy's air source. The question is...... do I need to carry a bail out.

As I see it, the answer is no.....

O-ring failures/regulator failures: the odds for failure drop tremendously when the equipment is serviced regularly and tested before use. That means tested before you go on the trip and after servicing. (Droping it off for service, after sitting around for five years, four days before flying off and then trusting it does not qualify.)

Proper dive planning, prevents running out of air during the dive and allows a reserve for buddy sharing ascents if ever necessary. Proper buddy procedures, followed correctly provide a second air source, a second set of eyes, and a second set of hands for incidents.

Proper weighting, allows for a few breaths of air to be stored in the BC and is available for breathing should A, B, and C fail. Heck I can turn my bag ( sorry, the bladder of my BC) into a rebreather for the short few minutes it will take to swim to the surface.

A bail out bottle is not necessary for recreational, non-decompression, diving within the recreational diving limits. Proper training, mental and physical preparation, equipment conditioning, and in water practices are.

Oops, that last comment flipped me to the other side, sorry I'll quit now.

 

[Lee Taylor]

Lee,

Why the desire not to use a pony? I ended up getting a 19 cu ft pony and slinging it, but I got the 19 precisely because I though a 30 was on the border of being too inconvenient of a size, and that I would start to decide against carrying it. So maybe the solution is to get a smaller pony?

Thank you Hobo,

You are right on target. For me its all about not having so much gear. Some divers look like overloaded Christmas trees. The lighter the better as far as I am concerned.

 

[String]

The christmas tree isnt really about carrying too much stuff (although some do). Most of it is due to poorly or completely un-thought out storage methods.

A 3l tank side slung most definitely doesnt look like a christmas tree.

 

[1_T_Submariner]

I'm just going to comment on the "Pinch the hose" comment. If your 1st stage fails to regulate the IP (pressure between the tank and the part in your mouth) and you pinch the hose your Octo will free flow. If you pinch both low pressure hoses then the weakest of them will burst if the pressure keeps going up.

I just had a regulator with the high pressure seat not sealing and the IP was in the mid 200's which it should have been 145'ish. My second stage free flowed etc... but not like you pushed the purge button it was just a slow stream of air. I think a failure in this seat could cause a bigger free flow though.


I have just added a pony to my equipment (not for the above reason) I like having 2 extra sources of air.

 

[ketchumid]

This is a photo of a 19cu on my back, (yellow tank- octo clipped on my right BC strap, a complete redundant air source. As a newer diver on a trip to Palau it gave me the confidence I needed. I've only used it once but for that trip it was perfect. On a sad note I did find that a lot of boats in HI did not allow me to bring it on with my gear, for various reasons, but mostly they didn't want to "fuss" with it.