Attaching bolt snap to SPG

[Caveeagle]

OOG plus a stuck boltsnap is a 6 sigma event.

I'd like to see the FMEA on this please.

...We did have a discussion on here recently with a diver that claimed to have two 2nd stage failures at the same time. Presumably from unseated exhaust valves splashing in at an odd angle.

I do believe in statistical analysis. ....I also believe in Murphey's Law.

 

[rhwestfall]

I meant "slide" as a form of "release"..... (not a problem, but a "solution"...)

 

[KevinNM]

If you are on a deco bottle, your buddy should be right? So he can just go to back gas if he runs out of deco gas, right? Or you can go to your back gas and hand him your deco reg? I'm trying to see how this situation could arise outside of some bizarre situation where you are diving a hypoxic backgas and only have one deco gas and are somehow trapped at 10 feet.

 

[kr2y5]

Curious how many OOG fatalities have occurred because a bolt snap was cave-lined to a long hose instead of on a breakaway. kensuf mentions guys that have died by being passed a stage that was low on gas, were these attributed to the donor being unable to deploy the backgas long hose? I'd like to read those reports. IUCRR links?

Still not sure why passing the stage reg and switching to your bungeed backgas for the 15 seconds it takes to sort a stuck bolt snap is such an emergency, even in a restriction, even in zero vis. I can remember doing this several times during various courses without issue.

It's a pretty big stretch to "OMGURGONDIE!!!!" Especially if you've done anything remotely akin to elementary gas planning.

I think if this were as serious an issue as made out to be, the WKPP/GUE guys would have been dropping like flies many times over, UTD the same. If you want a breakaway, go ahead, but let's not pretend that a cavelined bolt snap is going to result in your doom. If you're at that point in the dive, you've screwed up so much other stuff I highly doubt it's going to be the deciding factor.

OTOH, just to be fair to the other side of the argument... you could probably likewise ask how many fatalities have occurred because of a breakaway connection having broken away, and the subsequent loss of a life support boltsnap that unleashed the cascade of events leading to the diver's demise. I suspect you could similarly argue that it is not such a big deal, either. In that sense, both arguments seem to be similarly hypothetical...

 

[JohnnyC]

You're right kr2y5. The point is, it probably doesn't make any sort of difference. Although I have seen a couple guys with a 7 foot hose dangling on deco. Both used o-rings to "secure" their long hose. Did it hurt anything? Nah. More embarrassing than anything. Are there situations where it could be dangerous? Sure, but I doubt they rarely happen. I would be more concerned about banging the second stage around damaging the cave than anything else.

Interestingly enough, I remember seeing a video or a post somewhere that had a guy using a double ender bungeed pretty tight under the exhaust tee but I can't seem to find it. I'd be curious to see it again for comparison.

 

[joshk]

Interestingly enough, I remember seeing a video or a post somewhere that had a guy using a double ender bungeed pretty tight under the exhaust tee but I can't seem to find it. I'd be curious to see it again for comparison.

Maybe this?

 

[tbone1004]

Here are the pix of the Poseidon modification. Bungee is prusik'd through the bolt snap, then that is prusik'd around the end of the adapter which holds it in place. Snap it over the mouthpiece and you have a pretty darn secure attachment point that comes off super easily and you have enough space to breathe off of it before you cut it off if the bolt snap is broken

This is what the equivalent looks like for "normal" style second stages shown here on a Dacor Pacer I use for my O2 bottle. Same attachment point on the hose as the Poseidon, and using this thin 1/8" bungee, it is actually the same length loop.

I'm 99% sure this is what they were referencing above. Again, same length loop, but instead of prusiking it around the hose, you clip one side into each end of the double ender and if you have one end that is busted on the bolt snap, the whole thing comes off of the second stage. It is nifty, it works well, but I prefer the one above personally despite the double ender being lower profile. I find the double ender a bit harder to clip off, especially with gloves on because it is harder to grab hold of anything

 

[joshk]

Bungee is prusik'd through the bolt snap, then that is prusik'd around the end of the adapter which holds it in place.

FYI, that's a cow hitch.

 

[tbone1004]

FYI, that's a cow hitch.

symantics though a cow hitch requires a single end to be tied into an identical looking knot. It's actually a girth hitch since it is only "prusik'd" once where a true prusik hitch is typically done multiple times, but since it starts as a prusik loop instead of a single lead, it is not technically a cow hitch

 

[JohnnyC]

That's not it Joshk. It looks similar to what tbone posted but there's an actual video I'd like to watch.

It's a girth hitch, not a prussik. The action is to "choke" not "prussik" it.

A loop is only a prussik loop if it's intention is to be utilized as such.

Nobody actually cares what you call it.

/me is IRATA Level 3 and a professional rigger.