Fatality at Jersey Island

[John C. Ratliff]

I also found this on the Hollis website, a CO2 sensor to be used with their Explorer rebreather.

SeaRat

 

[KenGordon]

On page 2 of the Prism2 manual it say SGS UK Ltd Notified Body 0120

Gianaameri have you read the manual?

Ok that's great. It looks like and occupation workplace safety. Can the HSL negate the CE certification with an opinion?

You state that is was found to be non compliant.

I maybe wrong etc... (For the UK) But if HSL say to the HSE that such and such a piece of diving equipment is not CE compliant and the HSE takes the view that people at work must use CE compliant kit then the HSE can prohibit (paid) instructors using that kit.

The HSE are the people dodgy employers are afraid of. HSL is part of the HSE and the HSE take some interest in rebreathers.

From the consumers point of view the local council's trading standards department would become involved. This is very rare for CE violations and normally involves stuff like kettles with live bits and such like.

When I have built CE stuff it was always self certified. You need evidence it complies (the Technical File etc) but it wasn't like we sent a box off to be tested and a certificate turns up in the post. It is all a lot less black and white than you might think.

---------- Post added December 3rd, 2014 at 11:37 PM ----------

I also found this on the Hollis website, a CO2 sensor to be used with their Explorer rebreather.

SeaRat

Some rebreathers have an option for a co2 sensor. A rebreather isn't a nice place for sensors and (as far as I can tell) the co2 ones have not gained a high level of adoption as yet. There are reports of false positives from some people.

I think (I could easily be wrong) that there may be an upcoming paper on these. I think it was mentioned in the context of a study which did blind testing of prebreathing rebreathers to detect scrubber issues. I think it gave very pessimistic results as to divers ability to notice even a missing scrubber.

 

[Garth]

If air circulates forward or backward the scrubber still works... I don't see any point in arguing that..

The fact that it flooded will in fact cause an emergency that requires bailout.

Did this diver have bailout and why didn't she bailout? No BOV?

I don't like the screw in pieces compared to the bayonet of the hammerhead..


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[HIGHwing]

If air circulates forward or backward the scrubber still works... I don't see any point in arguing that..

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Just a clarification, in this case, the air was not circulating any more than breathing in and out of a balloon. Nothing was circulating in any direction.

Did this diver have bailout and why didn't she bailout? No BOV?


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Bailout from a CO2 hit? Unlikely at best.

 

[gobfish1]

If air circulates forward or backward the scrubber still works... I don't see any point in arguing that..

The fact that it flooded will in fact cause an emergency that requires bailout.

Did this diver have bailout and why didn't she bailout? No BOV?

I don't like the screw in pieces compared to the bayonet of the hammerhead..


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bail out , lol ffs . go stick your head in a bin bag and breath, keep your bail out reg in hand as you run up and down your living room ,

let us know how you get on ,

 

[Garth]

Just a clarification, in this case, the air was not circulating any more than breathing in and out of a balloon. Nothing was circulating in any direction.



Bailout from a CO2 hit? Unlikely at best.

What? If you breath out it goes somewhere in a counterlung and then into a scrubber. If the mushroom valves were both installed in same direction the air was going through the scrubber.

What you are suggesting is that one or both mushroom valves were not installed at all. Do you have that knowledge?

I dive a rebreather and understand the gas flow of a standard rebreather. Breathing in and out of a balloon suggests that either the mushroom valves were not installed, or the scrubber wasn't installed... Otherwise the scrubber is in play. If both mashroom valves are oriented in opposite directions you either can't breath in or you cant breathe out.

If an o ring was omitted fine then yes the scrubber may be bypassed but if the direction of flow is switched there is no reason why the scrubber wouldn't work...

Garth



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---------- Post added December 3rd, 2014 at 07:48 PM ----------

bail out , lol ffs . go stick your head in a bin bag and breath, keep your bail out reg in hand as you run up and down your living room ,

let us know how you get on ,

Did you not read my BOv comment. Are you denying that people have actually bailout out and survived a CO2 hit?

It's possible although not ideal to have a CO2 hit at all obviously.

A lot of these comments seem like they are coming from people who don't dive rebreathers... Just sayin.

Garth


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---------- Post added December 3rd, 2014 at 07:53 PM ----------

Just a clarification, in this case, the air was not circulating any more than breathing in and out of a balloon. Nothing was circulating in any direction.



Bailout from a CO2 hit? Unlikely at best.

You have a lot of Rebreathers listed in your profile but do you actually dive Rebreathers frequently or are you teaching often?

I'm not convinced this was a primary CO2 hit as opposed to a flooded rebreather event with building CO2.

Everyone has an opinion. No one has to like mine...

Breathing in a balloon... Not good for your health...


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[HIGHwing]

Why don't you page back a few pages and look at the photos and videos I posted on how she accomplished turning her P2 into a balloon. As soon as you see what she did, you'll say Holy I didn't know that was possible like the rest of us.

Please also see the coroner's report for COD.

BTW - The photos of the parts and rebreather are my P2.

 

[HIGHwing]

I'll take a look.. Hang on.


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Because you're trained on CCRs it's harder to visualize the error, to the point that I had to ask questions here in this thread to even understand it myself.

 

[Garth]

Wookie -

Imagine you have a four foot piece of garden hose. Both ends of this garden hose are open, making it essentially a long flexible straw. Now drill a small hole at the mid-point of the hose and affix a mouthpiece to the hole you drilled. I'll now ask you to imagine breathing through the drilled hole. As you inhale and exhale through the mouthpiece air will enter both sides of the hose and exit both sides of the hose (presumably equally for this discussion).

This is not a circuit, and does not represent how a rebreather is supposed to work. The stereo test proves that breathing gas can only move one direction.

Let's modify our imaginary length of hose with two simple one-way valves , i.e. the mushroom valves, or perhaps some call them check valves. The purpose of these valves (when properly installed) is to force the direction of gas to go only one way, in a circuit, if you will.

We'll now install a one-way valve to the left of the mouthpiece that opens only when the user inhales. We'll install a second one-way valve to the right of the mouthpiece that only opens when you exhale. What we have now is a hose connected to the mouthpiece that can only inhale from the left side and exhale from the right. It's the beginning of a circuit.

The stereo test for most manufacturers asks the diver to place the palm of their hand over the inhallation hose and prove that breathing gas is not bypassing the exhallation one-way valve. To complete the test you'll cover the exhale side and try to exhale verifying the inhale valve stays closed. If this works, you've proved that the valves are installed, they are working, and that you are breathing in a circuit. (Individual testing procedures vary).

In the accident victim's case both valves were to the right of the diver facing each other blocking the circuit and turning the machine into a linear breathing apparatus. By doing this, nothing forces breathing gas into the scrubber in any meaningful way and she was essentially diving a very fancy plastic bag.

Ok. Got what you are saying but how the heck do you not notice that the valves are pointed at each other. That's not linear that is a machine that you be unable to breathe from...


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---------- Post added December 3rd, 2014 at 08:06 PM ----------

Ok. Got what you are saying but how the heck do you not notice that the valves are pointed at each other. That's not linear that is a machine that you be unable to breathe from...


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Ok, my mind is thinking too. If the hoses were not assembled correctly that would mean there would be a lot of air escaping from that one connection, how that wasn't caught I have no idea.


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[HIGHwing]

Ok. Got what you are saying but how the heck do you not notice that the valves are pointed at each other. That's not linear that is a machine that you be unable to breathe from...


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The only possible answer is she did not build it. You can breathe from it - no problem. You just made a balloon. The valves facing each other essentially create a rubber stopper in the loop. You have access to the gas in the loop, bucket and CL but in a linear fashion.