Fatality at Jersey Island

[tstormdiver]

Can you elaborate on this a bit? My revo uses a basic Draeger DSV (inhale mushroom in a spider on my right, same thing for exhale on my left), and when I mentally flip the DSV I just don't see any problem for the DSV itself. Yes, I'll be pulling gas from the left and pushing it out to the right, and on the revo that's not good for a number of reasons...but it shouldn't hurt the mushrooms themselves. Am I missing something, or is it maybe the Hollis design different?

I did not say it would damage the mushroom valves, If the hoses of the lower loop are put in reverse, it would put the 2 mushroom valves together facing each other, so it would not work on an inhale nor exhale. The Prism2 works opposite- Inhale is on the left & exhale is on the right. One mushroom valve is on the inhale hose going into the DSV & the other is on the exhale side of the DSV. The threads on the DSV & corrosponding loop hose are keyed differently from one side to the other. You would not be able to completely screw the DSV onto the wrong hose without probably destroying the threads & you would not get a successful & proper positive or negative.pressure test

---------- Post added November 27th, 2014 at 06:53 PM ----------

How are the counterlungs attached to the harness?

Do they use identical types of Fastex buckles, like smaller versions of the waistband buckle? Those things are interchangeable, and even work inverted.

The counterlungs are attach up top by a "Y" shaped "yoke" that attches to the H-frame via the backplate & wing bolts, The CL's are held on by a double side flap of velcro, with the CL velcro sandwiched in between & a large buckle (like on a waist belt of a BC). There are straps that attach to the backplate & another to the waist belt attached by QD buckles. I personally use 2 snap bolts on either end of a piece of bungee, from 1 bottm Cl D-ring, routed through my crotch strap, up to the other side bottom CL D-ring (makng a "V") instead of the 2 straps.

 

[Dr. Lecter]

I did not say it would damage the mushroom valves, If the hoses of the lower loop are put in reverse, it would put the 2 mushroom valves together facing each other, so it would not work on an inhale nor exhale. The Prism2 works opposite- Inhale is on the left & exhale is on the right. One mushroom valve is on the inhale hose going into the DSV & the other is on the exhale side of the DSV. The threads on the DSV & corrosponding loop hose are keyed differently from one side to the other. You would not be able to completely screw the DSV onto the wrong hose without probably destroying the threads & you would not get a successful & proper positive or negative pressure test.

Ah, now I see, thank you. I had forgotten the hoses come off the DSV/BOV on a P2 and how the mushrooms are set up on it. On the revo's DSV, not only do the hoses stay attached to it, the spiders holding the mushrooms are both in the DSV: flipping the loop or the DSV itself would simply reverse the flow. Not so much with a P2, but as you say you'd have to really work to put it together backwards and even then it would fail +, -, and stereo checks.

If you still get in the water after that (or after skipping the checks), I'm not sure the unit has really failed the silly EU standard gianni keeps touting as adopted by "the" manufacturers. It's not possible to "assemble" it wrong, it's simply possible to kinda sorta jam pieces together wrong and even a single test out of the three basic ones run after a build should reveal the errors. Not sure any diver can really ask for more idiot-proofing than that.

Hopefully some testimony will come out from a dive buddy or other witness revealing something that will make some sense out of this. Rushing to build it on site/on a boat, while distracted, and skipping the checks is bad, but sometimes people do it. Sometimes it doesn't bite them, other times...

 

[Omisson]

I had been wondering why manufacturers introduced pre-packed disposable scrubbers (be that with granular absorbent or EAC).

Maybe they did to meet this requirement (“It shall not be possible to assemble or combine the components or parts in such a way that it can affect the safe operation and safe use of the apparatus, e.g. by incorrect connection of the hoses to the breathing circuit.”).

You must not forget the target market of the "PADI Type rebreathers" (they are for the ordinary divers, normal ordinary people who make ordinary mistakes if you give them the opportunity to, not necessarily people as good as you).

---------- Post added November 27th, 2014 at 05:29 PM ----------

Somebody else has published on the internet some more information, so here I repeat what they published:

The main findings of the inspection of the equipment were: The rebreather did not comply with clause 5.1 of BS EN 14143: 2013 or BS EN 14143: 2003, which states:
“It shall not be possible to assemble or combine the components or parts in such a way that it can affect the safe operation and safe use of the apparatus, e.g. by incorrect connection of the hoses to the breathing circuit.”
1) The rebreather had been put together such that the gas would not circulate in the required loop and CO2 would not be removed from the inhaled gas.
2) The inhale counter lung was positioned to the diver’s right hand side, instead of the left hand side.
3) The exhale counter lung was positioned to the diver’s left hand side, instead of the right hand side.
4) The one way inhale valve that should be positioned on the inhale side of the mouthpiece, to ensure the gas circulated the loop, was found butted against the one way exhale valve of the mouthpiece stopping any gas passing into the exhale counter lung on the diver’s right hand side.

There is 7 more bits of information which I have, but which yet remains unpublished on the internet.

Why is every time YOU start a thread you "know secret material" no one else has - or ever gets discovered?

You have 7 bits of information unpublished on the Internet? Then why mention it?

Reminds me of your "mystery cave" diving thread a few months back where you talked about a cave you would not identify because it was secret...y

At any rate the big "eu" standards you keep talking about is no more than a norm of the industry- and according to the rebreather manufacturers forum the Prisim 2 is EU compliant.

So please stop pretending to know what you are talking about... or stop making things up as you go.

It's pretty self evident you'd have to jam the counterpunch hoses on against the threads to get them on - and then they wouldn't give you the required predive all clear needed.

 

[tstormdiver]

Let's assume for a second that the counterlungs needed to be be cleaned individually and then reattached. Let's further assume a truly geometry-challenged person was putting them back on, and they pushed and shoved until the lopsided-looking things settled in place backwards over the harness.

It sounds like the velcro sandwich would allow a left counterlung to be securely attached to the right side of the harness.

Are the edges of the velcro blazoned with special matching fabric colors, to indicate a misplaced CL?




I see. Many thanks for your careful explanation.

Now suppose the counterlungs have been reversed, but the hoses (being keyed) stubbornly refuse to go on incorrectly. Suppose they are installed correctly by trial and error.

Would a distracted diver then notice if the loop and the DSV were upside-down? Does the mouthpiece have an indication for "up"?

Also, would it be possible to attach the over-the-shoulder hoses to the incorrect fittings on the head, or are the head hose fittings keyed as well?

The Counterlung hoses to the head are not keyed. The only keyed parts are the hoses for the lower loop & the DSV. If the counterlungs are installed in reverse, the fittings to the hoses from the regulator(s) are the same O2 or Diluent (standard LP inflator hoses). O2 can be plugged into the ADV & Diluent onto the manual O2 valve. They are only addition valves.... Now,.. Let's say the lower loop is installed as it should normally be (backwards to the counterlungs). Once again the keyed parts will not work together & should be caught in the Negative/ positive pressure tests. If, as in your scenario the lower loop is installed backwards also, then, of course the air flow would be reversed. That would cause the WOB to greatly increase because it is a radial scrubber & normally should flow from inside to outside,... in this case it would be trying to move from outside to inside. It should present such a higher WOB effort to be obvious. The biggest danger there would be from Oxygen toxicity because of the air moving backwards, the higher levels of O2 would be breathed by the diver before going past the O2 sensors, but CO2 should still be scrubbed. Whether the effeciency is changed because of the air moving from outside the scrubber to the inside,... I don't honestly know. The DSV lever would point up when it is closed (surface). There is also an arrow on the top of the DSV marking the direction of air flow (left to right). Look at the picture in post #44. Look at the difference in the counterlungs. If someone is that distracted or "geometry challenged" that they can not notice the difference in lungs, The no passage of air if the lower loop in incorrectly assembled, the failure of positive & negative pressure tests & if in theory, the unit is completely insalled backwards, that they can not notice a HUGE increase in the WOB, then they do not need to bein the water at all. If a diver is trying to assemble his unit "by trial & error", then either he has had not training or that training is woefully lacking in the most basic skills. There are assembly checklists for the unit & that is a required part of the course. Rebreathers require the diver's utmost attention. It is not the place to have your head "you know where". What you are suggesting would be akin to an OC diver Putting his regulator on the cylinder valve backwards & trying to get it to work.

 

[gianaameri]

The Counterlung hoses to the head are not keyed. The only keyed parts are the hoses for the lower loop & the DSV. If the counterlungs are installed in reverse, the fittings to the hoses from the regulator(s) are the same O2 or Diluent (standard LP inflator hoses). O2 can be plugged into the ADV & Diluent onto the manual O2 valve. They are only addition valves.... Now,.. Let's say the lower loop is installed as it should normally be (backwards to the counterlungs). Once again the keyed parts will not work together & should be caught in the Negative/ positive pressure tests. If, as in your scenario the lower loop is installed backwards also, then, of course the air flow would be reversed. That would cause the WOB to greatly increase because it is a radial scrubber & normally should flow from inside to outside,... in this case it would be trying to move from outside to inside. It should present such a higher WOB effort to be obvious. The biggest danger there would be from Oxygen toxicity because of the air moving backwards, the higher levels of O2 would be breathed by the diver before going past the O2 sensors, but CO2 should still be scrubbed. Whether the effeciency is changed because of the air moving from outside the scrubber to the inside,... I don't honestly know. The DSV lever would point up when it is closed (surface). There is also an arrow on the top of the DSV marking the direction of air flow (left to right). Look at the picture in post #44. Look at the difference in the counterlungs. If someone is that distracted or "geometry challenged" that they can not notice the difference in lungs, The no passage of air if the lower loop in incorrectly assembled, the failure of positive & negative pressure tests & if in theory, the unit is completely insalled backwards, that they can not notice a HUGE increase in the WOB, then they do not need to bein the water at all. If a diver is trying to assemble his unit "by trial & error", then either he has had not training or that training is woefully lacking in the most basic skills. There are assembly checklists for the unit & that is a required part of the course. Rebreathers require the diver's utmost attention. It is not the place to have your head "you know where". What you are suggesting would be akin to an OC diver Putting his regulator on the cylinder valve backwards & trying to get it to work.

The unit was analysed by a major test lab and some of the conclusions posted earlier come from the lab. There must be a way that the user was able to assemble the unit the way she did.

She did a 5 minute pre-breathe, in accordance to industry practice and manufacturer instructions, but despite this she did not perceive anything wrong.

Second lesson to be learned and this I posted before long ago - a 5 minute pre-breathe is insufficient to detect CO2 problems - do 10 minutes minimum.

I am a risk manager and gather data and analyse facts before reaching conclusions.

There is other lessons to be learned, particularly considering the deceased is the target market of the PADI Type Rebreathers and was an OC dive instructor.

User beware.

 

[tstormdiver]

The unit was analysed by a major test lab and some of the conclusions posted earlier come from the lab. There must be a way that the user was able to assemble the unit the way she did.

She did a 5 minute pre-breathe, in accordance to industry practice and manufacturer instructions, but despite this she did not perceive anything wrong.

Second lesson to be learned and this I posted before long ago - a 5 minute pre-breathe is insufficient to detect CO2 problems - do 10 minutes minimum.

I am a risk manager and gather data and analyse facts before reaching conclusions.

There is other lessons to be learned, particularly considering the deceased is the target market of the PADI Type Rebreathers and was an OC dive instructor.

User beware.

Do you seriously consider the Prism2 at "PADI Style" CCR? I certainly do not. I won't say it is the most complicated, but it definitely is not the simplest either. The Posiedon MKVI maybe,... since it automatically does the checklists & operational tests, & is known to signal an abort to the dive, if the slightest thing is not correct & uses pre- packed canisters. I've never dove one, but have seen them in operation closely many times & they are quite finicky. The Prism2 require the diver to pack the canister, & to preform all operational checks. I have always done a 10 minute pre- breathe. That is what I was taught to do. Whether that is what others agree or disagree with, that's their thing. Risk management is also what my instructor drilled into me. Whether it be Decompression diving, cave or CCR. He has taught me to think outside the normal box of "what if's" & to try to consider beyond that,... however with the understanding that there is always some risk & how much risk I am willing to accept with the education I have.

 

[gianaameri]

Bits posted by a conspirator elsewhere on the net:

- The unit was flooded with fluid.

- The cover for the scrubber bucket and head were missing, apart from a small piece attached to the fitting above the battery housing.

- Two of the three oxygen sensors were reading 0.18 and 0.16 partial pressure of oxygen (ppO2) when exposed to air (0.21 ppO2), and when put into a 100% oxygen atmosphere (1.00ppO2) gave a reading of 0.80 oxygen. The third indicated 0.00 oxygen in air and 0.28 in 100% oxygen. Images received with the equipment taken by the Jersey Police indicate that the sensors appeared to be working correctly at the time of the incident. The subsequent reduction in oxygen sensor readings was due to the sensors being contaminated by the fluid within the rebreather damaging the oxygen sensors.

 

[Dr. Lecter]

The unit was analysed by a major test lab and some of the conclusions posted earlier come from the lab. There must be a way that the user was able to assemble the unit the way she did.

She did a 5 minute pre-breathe, in accordance to industry practice and manufacturer instructions, but despite this she did not perceive anything wrong.

Second lesson to be learned and this I posted before long ago - a 5 minute pre-breathe is insufficient to detect CO2 problems - do 10 minutes minimum.

I am a risk manager and gather data and analyse facts before reaching conclusions.

There is other lessons to be learned, particularly considering the deceased is the target market of the PADI Type Rebreathers and was an OC dive instructor.

User beware.

Your definition of "assemble" leaves much to be desired.

 

[gianaameri]

Your definition of "assemble" leaves much to be desired.

She had two other fellow rebreather buddies who were unable to help or save her.

To them she and her equipment looked fine till she was lost and later found dead.

She was dead in 3 minutes from beginning the dive after a 5 minute pre-breathe.

PADI Tek Rebreather and PADI Buddy System in this instance (and many other documented ones did not work).

Third lesson learned, Solo or Buddy (and this PADI or Tekkie) the rebreather kills you (be that due to equipment failure or user error or both and whichever comes first).

 

[rongoodman]

Now I'm really confused. Did she have a CO2 hit because she built the unit improperly, or a flood? Or did the flood and possible subsequent damage to the the O2 cells come after the incident, when the loop was out of her mouth? As for the lungs being reversed, even though the fittings are the same for O2 and diluent addition, the hose routing is completely different--how could anyone familiar with the unit possibly miss that?