CO2 Incident

jkaterenchuk

There have certainly been an uptick in the number of safety awarness posts over the last month. I believe this is a good thing. Some of the recent personal incidents that have been shared got me thinking if there was anything in my 1 1/2 years experence of diving eCCR and now mCCR that I might be able to share with the community.

One occurance about 3 months ago came to mind. Here are the details.

We were diving a 40M wreck in warm water and had completed our setups and checks on the boat and also our surface equipment check before decending. I was diving a relatively new unit for me (Kiss Classic) with the stock Paragon BOV. In the past I had dived a Inspiration with HH and Golem BOV.

Before decending I turned the BOV knob from OC to Loop and it would not turn all the way. Maybe 75% of the way to loop position. My buddy had already decended down to 2M where we do our bubble check. I tried to cycle the BOV back and forth from OC to Loop a couple of times without luck. At about that time my buddy resurfaced wondering why I had not yet decended. I told him I was having trouble turning the BOV to loop and tried it again and it went all the way to loop. I turned it back and forth between OC and loop a couple more time and it seem to be working fine. So I thought we were good to go (foolish me) and we did our decent and checks at 2M, 5M and 10M.

The current was running pretty good on the wreck and visability on the decent was maybe 3M. My buddy was leading the way down and it was one of those hand over hand pull yourself down the line decents. Because of this I had to work pretty hard getting down and as I would have expected my rate of breathing went up. I am a pretty fit guy for my age and run on a regular basis so I was getting mildly concerned when I felt I was working harder and breathing harder than normal so I slowed down slightly and confirmed once again that PO2 was fine. I knew it would be since I general run a high PO2 on the surface and then control the PO2 on decent with triggering the ADV. But for some reason I just needed to check it again.

By now my buddy was beyond the range of visability so I resumed the previous work and decent rate but my concern grew to a point at which I said to myself..."this is alot of work that I know will be better on the wreck and the wreck cant be that much further....but I should not be breathing this hard". So my next move was to switch over the BOV to OC.

Those of you that have used the Paragon will not be surprised as it immediatly started to free flow so I had to bail to my OC bailout. Within 2-3 breaths my breathing was back to normal and I proceed down to the wreck where my buddy was waiting with a confused look on his face wonder what was taking me so long. We thumbed the dive at that point and returned back to the surface.

Later upon disassembly of the unit I found the exhale mouthpiece flapper valve in the bottom of the scrubber. I was not able to find the screw and nut that secure the valve in place on the Kiss Classic so I suspect they were the reason that the BOV would not fully move to the loop position on the surface.

One of the things that I was thankful for in hindsight was that following my initial CCR course I had taken the time to do a control couch test to determine how a CO2 hit would feel and what my signs and symptoms would be. That gave me the knowledge that my single sign of an impeding CO2 hit was increase in breathing rate. I am not recommending that anyone else do this controled CO2 test as I understand there are some medical risks for a small percentage of the population but it made me more aware of monitoring my breathing rate and at what point I should become suspicious that I had crossed over the line from working hard into hypercapnia.

Hope my story is of help to someone.

John

ScubaDadMiami

Thanks for letting us know about your story and what you learned.

__________________
Howard Packer
IANTD CCR Instructor
Miami Beach, Florida
CCRDiveTraining.com

mempilot

John,

Thanks for sharing. I like to read these happy ending accounts, as I always learn something from them. It may not be apples to apples with my unit for obvious reasons, but it makes me think about similiar parts that I don't check regularly.

I used to find my DSV lever loose from time to time and would just hand tighten it. When I did my first DSV overhaul, I realized how severe this could be if the screw backed out far enough and the lever came off. I now use locktite on the screw.

This reminds me, it's probably about time for that overhaul again to inspect the mushroom valves and relube the barrel.

Thanks for the story. Here's some green.

Eric

__________________
MEM "Da Pilot"

Black holes are where God divided by zero.

"If at first you don't succeed, don't dive silent."

"Would you mind not shooting at the thermo-nuclear weapons." ~ Vic Deakins

"Donkey's kill more people annually than plane crashes."

jkaterenchuk

Thanks Eric....Let me save you the time and money to overhaul it....I understand you will be replacing it with a Optima soon.....at least thats what I have been told.

I look forward to doing some diving with you when I come down in May....either on the Meg or your new Optima.

John

mempilot

Where do these rumors get started?? ADRIAN!!!!!!!!!

__________________
MEM "Da Pilot"

Black holes are where God divided by zero.

"If at first you don't succeed, don't dive silent."

"Would you mind not shooting at the thermo-nuclear weapons." ~ Vic Deakins

"Donkey's kill more people annually than plane crashes."

JCdesign97

Jees, I leave one thread trying to go easy on you and here it is in another, Eric! It seems like everyone else knows your inner workings better than you do!! Congrats and good luck with the Optima - you'll love it ...

__________________
Cheers,

John

Gill Envy

john, thanks for posting! these kind of posts are more enjoyable and probably educational than speculative arguments about fatalities. I'm glad people like you are feeling comfortable sharing them! have some greeeen!

__________________
Gill Envy

...Because I wasn't born with gills!
><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>

divelermentov

Hi John

good to hear that none of you got hurt.

Please forgive my ignorance but what is a control couch test ?
cheers
christian

__________________
May The Sorb Be With You

jkaterenchuk

Breathing off the loop with no CO2 absorbent in a controlled enviroment with appropriate safety precautions and help.


or in other words while sitting on the couch watching tv or reading Rebreather World.

osiris

Could it be the "milkman who swerved to avoid a child and fell of the couch" sort of a couch test?