HP hose failure at max penetrartion
I thought I would do a write up on an incident I had this weekend at Ginnie. It is a very minor incident, one probably many people have had, but thought writing it up is a good learning experience for others.
My wife and I decided to scooter Ginnie on Saturday. We did the dive on backgas, not carrying a stage. I don't want to get hung up on that point as it's a debatable point. Many people are taught to never scooter without carrying a stage, while others are taught to scooter on backgas after performing the appropriate gas calculations. Either way, the plan was to just do a simple, easy dive to very conservative 1/3s ( I won't go into what that means to us exactly other than to say we don't believe in diving full 1/3s and when a scooter is involved we turn way,way before 1/3s). The dive was up the bone line, jump back onto the mainline, then turn at the area just past sweet surprise where the line takes a hard right around a corner then continues straight. I believe that is 22-2400p. This is a dive we've done several times before, so we know what our gas supply is at the turn point and if we're burning more gas than that to turn earlier.
The dive was routine and easy, and both our gas consumptions were better than normal. I was the second diver, becoming the lead as we turned it with very, very conservative gas remaining. As I usually do when I turn the dive, I rechecked pressure on both sidemount tanks, got the OK to proceed out and continued on my merry way. Within 30 seconds, I received and emergency light signal, and before I could even turn around my wife was in my face with her long hose in her right hand and was shutting down my right tank at the same time. I was on my left tank, so I had no need to accept the donation. It took me a second to realize she had started shutting down my tank. When I looked down all was ok, so once we were collected I turned on the tank to find a decent steam of air escaping from my hp spg hose where the hose attaches to the crimp fitting on the first stage end. I examined the hose further and saw it had completely ruptured. I checked my spg on that side and it showed 600 psi. I knew there was no way I could have lost well over 2-2500 psi in that short amount of time. We exited the cave at a decent speed on the scooters, leaving our jumps and exiting via the mainline, while being prepared to feather the valve on the way out if necessary (but with the amount of gas available in the left tank that never would have been necessary even if both scooters failed and we had to swim out.)
There were a few things I learned from the incident. Firstly, just as your instructors warn, we were of course at max penetration when the issue occurred. Being extremely conservative and living by the rule of progressive penetration made the exit out completely non-stressful. I've always been told a hp hose failure is a much less severe problem than a lp hose. That is obviously very true as I never heard a thing, and because I was on a scooter I never saw any bubbling. I would have not caught the problem likely until the next time I checked my spg. I always assumed that even with a hp failure you would hear it. I also didn't think about the fact that I may still get an spg reading, and especially how inaccurate it would be. After the dive I checked the affected tank and had only lost 300psi. So obviously don't believe your spg in that case. Having a stage obviously would have given us even more gas to deal with the issue, but was not a necessity as we calculated our gas needs and knew how to be conservative based on having done the dive before.
As for the cause of the hp failure, it actually wasn't a complete surprise. My spgs are on rear facing 6 inch hoses. I don't generally bend the hose around to view my spg because I've already noted that doing that puts heavy strain on the hose at the crimp. I generally pull my tank forward by the valve if I need a closer look, but do on occasion have to bend the spg forward some when I'm really having trouble seeing it. I inspect the spg hoses at the crimp regularly due to that fact. It now is making me considering going back to 9 inch spg hoses, which I wasn't a big fan of.
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Originally Posted by LMN
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