Rebreather Discussion from Brockville Incident

[gianaameri]

You always seem to get bogged down with the scematics of the written word and I have been reading this dribble on the other forums too.

Rebreathers do not kill people, people kill people!

Guns do not kill people, people kill people!

See the common denominator yet?

Regardless of how any standard is written, it will always be up to the people to keep their own arses alive. There will never be a perfect rebreather and no matter how much fuss you make about how the standards are written, you will always be able to find another loop hole to make a stink about.

I am not saying that your actions to attempt to get the manufacturers to improve upon safety is a bad thing, but CE standards still don't mean jack crap over here in the USA.

Guns do meet safety standards (SAAMI in the U.S. and C.I.P. in the EU).

If they did not, guns would kill people (working pressure in my gun is 4200 bar and it is pressure tested to 5250 bars).

Ammunition and gun chamber meet strict specs. for match (or if they don't they kill people).

So, guns have their own "Functional Safety" standards.

Rebreathers have no safety standards to meet in the U.S. (unlike guns), but they do have safety standards to meet in the EU.

I think an equivalent manufacturer association like SAAMI (guns), but for rebreathers could go a long way to improve safety standards in the U.S.

For guns, C.I.P. and SAAMI standards have generally converged.

Before you post, it will help if you get your facts straight.

Now, you will see there is a common denominator for airplanes, anesthesia machines, and guns - with rebreathers being the odd one out lacking the Functional Safety which the others have.


---------- Post added July 5th, 2013 at 04:09 PM ----------

IEC 61508 Part 1 through 7 which is referenced in the link would be helpful also.

Thanks for the initial link.

Google search for the following:

CASS TEMPLATES FOR SOFTWARE REQUIREMENTS IN RELATION TO IEC 61508 PART 3 SAFETY FUNCTION ASSESSMENT Version 1.0 (5128) Report No. T6A01 Prepared for: The CASS Scheme Ltd By: The 61508 Association

IEC 61508: An Intoduction To the Safety Standard for End-users, Dr. M. J. M. Houtermans

Human Factor in Functional Safety, Pasquale Fanelli

Proposed framework for addressing human factors in IEC 61508, Prepared by Amey VECTRA Limited for the Health and Safety Executive

DIVING REBREATHING APPARATUS TESTING AND STANDARDS UK/EU PERSPECTIVE, Gavin Anthony, M.Sc., Principal Consultant Diving and Life Support, QinetiQ Alverstoke, Gosport, Hampshire, United Kingdom

Managing competence for safety-related systems Part 1: Key guidance, HSE

 

[InTheDrink]

I suspect that perhaps Lynne's point may be important. Technical diving needs to be more selective.

My buddy suggested I train CCR.
I said No, too dangerous, but gave in.
Half way thru my course my instructor asked me to go away for an hour and think about whether I wanted to continue as he said something along the lines of 'are you sure this is for you? You don't want to die this way'.

I came back after an hour, said yes, and aced the rest of the week.

Then went to cross over on another CCR. And came as near to meeting your maker as you get without permanent lodging.

I wasn't ready for it. Everything was my fault (apart from perhaps a too tight ADV but even that was user error).

The point is that CCR is not for everyone. Some people are naturals, other ppl, like me, just aren't.

CCR has higher inherent risks than OC. And whilst we don't have the apples and apples comparisons I think the 'CCRs don't kill, ppl do' brigade is just misleading. Sure, pilot error is mostly going to be the primary cause (altho not exclusively) but rebreathers are dangerous. The two manuals that I've studied ram as much down your throat.

The big question for me is why rebreather divers, in general, are so defensive?

 

[dfx]

Be aware that this is the current applicable standard, and that it will be replaced soon by a new standard (probably to be called EN14143:2013).

Because Clause 5.13.1 of the current standard could not be met by the rebreather industry (i.e. in respect of electronic rebreathers currently available to the general public), it was decided to remove such Clause altogether.

This is the part that you need to provide references for. Everyone can google the documents you refer to.

You're saying that currently available rebreathers have been certified to meet EN14143:2003 even though their electrical/electronic parts either haven't been properly tested under IEC 61508, or have been tested and failed the test, and that everybody knows about this but nobody does anything about it, while at the same time there are no publicly available sources to testify that.

The moon landing was staged too, right?

 

[Bluebeard45]

I would just like to add my 2 cents worth, especially being a Poseidon CCR owner/user. I bet the number one cause of non-physiologic deaths of all divers is...wait for it... car accidents. Rebreathers have come a long way. I took many courses (through RAID) and found the Poseidon the easiest / simplest to use although the trade off is that it is almost strictly recreational in its present form, and thats fine with me. A bailout bottle and lots of training should be mandatory. Saying that, when I came back from Florida with my rebreather certification and went to Divemaster training with my regular OC gear, I had a free flow from my one Zeagle second stages I have had for years, the next week I had a free flow from my 1 year old Zeagle reg due to the first stage. The dive shop I used to repair them (not where I bought them) says, well, these things do happen and explained the testing and guts of each component. My frist open water dive (10 plus years ago) in fact I had the high pressure cord tear open when just 5 feet under water. I have been using a pony bottle on all dives over 30 feet deep ever since. I have many certifications simply to learn all the ways you can die diving so I can avoid them. If you read 'The Last Dive" and "Deep Descent", none of these deaths were on rebreathers. I read that Nitrox for years was considered high tech by some agencies, now it is embraced. Hopefully rebreathers will too. Remember BCDs were not around when I was young and the word SCUBA also was born in my lifetime.

 

[Brad_Horn]

You're saying that currently available rebreathers have been certified to meet EN14143:2003 even though their electrical/electronic parts either haven't been properly tested under IEC 61508, or have been tested and failed the test, and that everybody knows about this but nobody does anything about it, while at the same time there are no publicly available sources to testify that.

DFX, If someone else can jump in, its not exactly hard for anyone to prove - a quick look at the manufacturers websites for all rebreathers that are CE marked gives a pretty quick answer. AFAIK there are only 2 notified bodies worldwide that can audit a diving equipment manufacturer to 61508: SIRA and TUV.
No published certificate to EN61508 means that product either fails 61508 or what is most probably likely the manufacturer hasn't bothered ensuring their product meets that standard:
Inspiration Closed Circuit Rebreather Manufacturer | Ambient Pressure Diving
VR Technology Holdings Ltd
submatix.com
http://www.revo-rebreathers.com/
A REBREATHER CHOSEN BY DEMANDING DIVERS - JJ-CCR
InnerSpace Systems Corp
http://www.poseidon.com/products/rebreathers

You may find a EN14143 or prEN14143 or even EN14143:2003 certificate on the above sites but other than one example below none will be able to provide a 61508 cert as proof of audit to that standard despite this being required in EN14143:2003 for the past decade.

As an example, a rebreather with electronics [not yet shipped to customers as Gian carefully worded around] that has both EN14143:2003 and EN61508 certification is the Apocalypse Type IV iCCR so its obviously very achievable as a standard for a rebreather to be certified to.
Its EN14143:2003 certificate is at https://www.opensafety.eu/certificates/CE_OSEL_Apocalypse_iCCR.pdf
Its EN61508 process certificate for SIL3 is at https://www.opensafety.eu/certificates/EN61508_cert_SIRA_DL_040310.pdf https://www.opensafety.eu/certificates/DL_FSM_CoC_S001_100305-1.pdf

A list of companies with EN61508 certification in the UK can be found at http://www.cass.uk.net/PDF's/CASS30-Rev-0C_CASS Scheme Certificates.pdf
Obviously the above well known rebreather manufacturers without EN61508 are noticeably absent from this list

Regards
Brad

 

[ianr33]

The big question for me is why rebreather divers, in general, are so defensive?

They doth protest too much,methinks.

 

[dfx]

You may find a EN14143 or prEN14143 or even EN14143:2003 certificate on the above sites ...

I may, but I don't. I found some references to some specific parts of the standard, but nothing claiming that anything complies to it as a whole. Thanks for at least trying to provide some references though.

 

[HIGHwing]

I don't really understand the point of comparing OC to CCR. I never operate my CCR without OC and I look at the lot of equipment as my complete diving system for the particular dive. I'm depending on my OC equipment to complete my dive just as I am my CCR to continue the dive. Granted, I'm not expecting to use my OC equipment any more than a sport diver is actually planing to end a dive in an air-share.

I really believe the difference in getting off the loop when something is awry is going to be a function of training, experience, and awareness. All this back and forth about CC/OC is fun banter, but really the CCR is simply augmenting for OC gas on any given dive. It's probably worth considering the entire dive system failed the diver if the CCR diver never made it to OC gas in the event of an emergency.

Acknowledging the rather scant data, it's clear [to me] divers are failing the machines in the majority of fatalities. I wonder how many CCR divers are certified but not really qualified anymore borrowing from my lack of currency argument above. People keep making the parallel between pilots and CCR divers leaning on the correlation of training requirements for bigger and bigger airplanes. These individuals are missing the mark with that parallel because every pilot has a recurrency requirement. Once you get a CCR card, you can take a 5 year break and you're just as certified as the day you walked out of the class half a decade earlier. Are you current, safe, and capable? No way. Being a certificated airman, I have constant recurrency requirements for Day, Night, Instrument, Multi, and per airframe where insurance requirements or the aircraft is over 12,500#s, or turbine, etc.

You give me a rebreather card, I'm current for life.

 

[nadwidny]

Planes are properly certified to meet Functional Safety blahblahblah

Ann Marie? Is this you??? The way you totally miss my point and go off on your own tangent a la RBW 2008 seems very familiar.

 

[shoredivr]

Brad, a quick look around for the Apocalypse rebreather didn't seem to indicate they are available to ship/dive yet, unless I'm missing something.