Do You Know What Your Oxygen Cells Do When Water Blocked?

[Brad_Horn]

This is exactly my point. It is ludicrous to suggest that manufacturers do not know this.

There are two easily checked facts:
1) That Oxygen must flow in and out of the cells freely in order for the diver to know their PPO2, and if the cell face was to be blocked by water, then the cell will continue to show the same PPO2 as before the water block occurred.
2) Is the carriage retaining the cells, of such a design that it easily floods the cell faces, during routine diving.

1) You can check manufacturers knowledge by a) asking the manufacturer or b) referring to their published documentation to see if the cells "freezing" when water blocked was considered in the units design and/or for operation.
2) You can check by physically looking at the rebreather in question. Or after diving it see if the oxygen cells have excessive water on their cell faces.

This thread is just another example of your insatiable need to bash competitors under the guise of providing authoritative information.

Sorry Simon, it is nice you are so defensive but please checks your facts.

If it were bash worthy - rather than cringe worthy - I would publish their names. In this case I will see how things play out.
and are you seriously claiming that the publishing of information relating to the safe operation of rebreathers shouldn't be discussed?

If you think you have discovered some issue of high relevance to the technical diving community and you want to disseminate in a credible manner, why don't you do what real scientists do and submit your work to a properly peer reviewed scientific journal.

Because it is already in properly peer reviewed scientific journals. Ones you very likely edited. See above links.... And still there is ignorance of the issue at the root level.

Additionally History, Travel, Arts, Science, People, Places | Smithsonian

Highest point of the loop and ~1cm apart, so how are they not flooding at the same time? Besides if the unit is flooded who cares? You can't breath through water.

Because if you know your going to go inverted, it is sensible to purge the loop of any water first by drawing the CLs and scrubber. The internal snorkels will hold 500ml-1L but why risk it.

If you have an old cell, see how much water it takes to flood the cell face. It isn't much. Even do this after purging it with O2, water block it and then see what it reads in Air....
Your cells freezing from water blocking and the Rb flooding are two seperate entities.

Additionally for what it is worth in 8 years of Apoc's being dived in eCCR, iCCR and mCCR configurations, I am not aware of any reported issues from water blocking of the cells: be they DL or R22 spec's. Bar what DL have themselves reported during prototype trials in 2008 when they first highlighted the importance of the issue.

Also not sure why molex connectors are inadequate and only coax connectors are acceptable? At least according to this pdf... I do appreciate the temperature testing, I think its great you did that bit.

Molex only offers a single point of contact. There is no reason not to use Coax. DL were unable to get use of Molex connectors CE certified for their rebreather designs. It also goes back to written advice provided by AD, to a rebreather manufacturer in 2000, which they then later incorporated...

The temperature testing was enlightening. Especially as to how others, tested to the EN14143 requirements, when certain cells inverted their readings at 45'C.... Again, something that shows the importance of unmanned testing of rebreathers.

 

[Tassi Devil Diver]

Haa.... these guys have zero credibility.

The quote bellow from Randy Thornton of CCR explorers puts this thread in perspective (Do you know what your oxygen cells do when water blocked? - Page 3)

Brad,

Let's cut the crap and tell the members of CCRX what you are up to. Alex Deas is a professional witness on the Wes Skiles law suit and you Brad, have been hired by the prosecution to try and bolster Alex's testimony. Your claimed altruistic desires to help the community are falling flat given that you are being paid to try and establish a plausible explanation to why the machine Wes was diving somehow managed to kill him. Never mind that he wasn't certified on it, the cells were old, he was solo diving without bailout, he was not trained on the machine, he had numerous drugs in his system, the machine continued to warn him with numerous alarms and so on and so forth.

I find it very distasteful that you are trying to use CCRX membership to give some level of credibility to what is most certainly the weakest case ever assembled in a product liability case. Grasping at straws comes to mind. Your pseudo science and investigative techniques are not welcome here and the fact that you do not divulge your true motivations while trying to pray on the emotions of grieving family members while lining the pockets of both you and Deas is beyond believable!

Take your dribble somewhere else where people actually appreciate ambulance chasing attorneys. (Not sure where that might be, but I'm sure you can find some like minded people somewhere!)

 

[The Chairman]

are you seriously claiming that the publishing of information relating to the safe operation of rebreathers shouldn't be discussed?

We get enough FUDDD with the politicos. FUDDD: Fear, Uncertainty, Doubt, Distortion and Deceipt. We expect more from intelligent discussions about the sport we love. A lot more. It's not that I mind a spirited debate or even some controversy, but I don't like tilting at windmills of another man's making. So, by all means, let's discuss information, real information, but let's leave the FUDDD on facebook.

There is a lot of FUDDD used in product competition and it's usually counter productive. It's not enough for some to tell the world why they're superior but that "you're gonna die!" if you use the competitor's product. The line "all will be revealed in time" gives the air of some inside knowledge that you're not willing to share. Why? Why not tell us now? The all knowing snarky rejoinders make you come across more as a used car salesman rather than a credible source. It's just not cool to smear people in such a manner that there is no way for them to refute your statements. If you have something worth our consideration, please trot it out. If you don't, then stop trying to disparage other manufacturers with made up nonsense. We're just not that dumb.

 

[Dr Simon Mitchell]

are you seriously claiming that the publishing of information relating to the safe operation of rebreathers shouldn't be discussed

Of course not, but that is not what you are doing here. You are dressing up a largely unsubstantiated collective attack on other rebreather manufacturers as discussion of rebreather safety. If you were really concerned simply about safety you could have described the specifics of your concern without once mentioning other manufacturers or their "ignorance" but that would not serve your true purpose would it?

Simon M

 

[oya]

You know, I've been following the entire Apoc rebreather thing for many years now... and I still have no idea what the hell that thing is.

Never seen one in real life, but from all the CAD drawings and "papers" that talk about how awesome it would totally be it looks about as complicated as a space shuttle and just ludicrously over-engineered to make every effort to protect a diver from being incompetent. It's like the exact opposite of the KISS.

And what the hell does the "i" in iCCR stand for?

Granted: My confusion is probably in part because the website sucks and I lose interest pretty quickly when I see pages upon pages that refer to CE ratings when I can't find so much as a unit schematic.

 

[matt_w]

You know, I've been following the entire Apoc rebreather thing for many years now... and I still have no idea what the hell that thing is.

Never seen one in real life, but from all the CAD drawings and "papers" that talk about how awesome it would totally be it looks about as complicated as a space shuttle and just ludicrously over-engineered to make every effort to protect a diver from being incompetent. It's like the exact opposite of the KISS.

And what the hell does the "i" in iCCR stand for?

Granted: My confusion is probably in part because the website sucks and I lose interest pretty quickly when I see pages upon pages that refer to CE ratings when I can't find so much as a unit schematic.

Just know it will be great and apparently anything else will (or maybe(but probably not)) kill you. Asking for specifics is stifling open discussion (in some way that I am not totally clear on).

 

[String]

if the cell face was to be blocked by water, then the cell will continue to show the same PPO2 as before the water block occurred.

No it won't. You've spammed this on various forums now and been corrected then shot down in flames over your claims now and previously.

You got busted on TDF and Randy Thorntons CCRX response was spot on. Simply posting the same thing everywhere doesn't make it any more true.

 

[boulderjohn]

No it won't. You've spammed this on various forums now and been corrected then shot down in flames over your claims now and previously.

You got busted on TDF and Randy Thorntons CCRX response was spot on. Simply posting the same thing everywhere doesn't make it any more true.

Could you summarize or quote?

 

[68raggtop]

Post 12 has the response in it.

 

[rjack321]

Could you summarize or quote?

He's fishing for validation on forums because Mr. Deas and/or Mr. Horn are acting as "expert" witnesses in a lawsuit over Wes Skiles death on an optima CCR. If you think that what you say here can't be used as evidence about what "everyone" knew or didn't know you're sadly mistaken.