Rebreather accident analysis

cedricverdier · 22nd June 2005, 16:32

Hi all,

We all know Sheck Exley's Accident Analysis that was so useful in decreasing the number of accident in the cave diving community. The idea was to find out the most common factors in the cave diving fatalities. The causes were several times redefined but are pretty much the famous:
- Lack of Training
- Lack of a continuous guideline
- Not enough gas
- Too deep for the mix
- Lack of 3 lights

Obviously that doesn't match with the rebreather diving fatalities that occured in the last few years. It would be great if the rebreather diving community could find a similar list of causes.
Some ideas could also be: Complacency and distraction (cf Tom Mount's last book), exceeding physiological limits (O2, N2, etc), equipment failure...

So what's your list of causes and their order of importance?

Cheers

***caveseeker7*** · 22nd June 2005, 16:56

Cedric,

I believe the biggest problem when it comes to rebreather accidents, fatalities or not, is the analysis itself. Usually, it seriously lacks, evidence is lost or destroyed, hence accurate findings are hard to come by. Therefor answering your question with a high degree of certainty is next to impossible. In addition, actual analysis data is more often than not impossible to access.

Madmole has done a commendable job trying to accumulate data on Inspiration fatalities, and there seem to be some common factors. If any or all of them were the actual cause however is hard to determine with the available data.

I've discussed the need for guidlines for evidence collection in regards to rebreather accidents with Rob Davie. As a law enforcement officer, public safety diving instructor and rebreather diver/instructor is well aquainted with both evidence collection and rebreather technology. It's a tough nut to crack.

When an accident occurs, and the equipment is actually recovered, the gas in the loop is probably the most important evidence there is. How often is gear checked by the diver or a buddy, before the gas can be secured and analyzed? How often the condition of the unit changed - tanks opened or closed, buttons pushed, DSVs opened or closed ... ? To make it even harder, a cmf rebreather would probably need a different protocol than an eCCR. Add to that the myriad of authorities involved, and the fact most no one knows rebreathers, much less specific units, and the task becomes almost impossible.

Even if a standard was devised, getting it to everyone involved would be a tall order.

To top it all off, some issues like the bodies response to CO2 are not all that well known, vary highly and may be interpreted the wrong way. Look at Iain's excellent post in the Rebreather/heart attack thread.

Just my 2¢

Crazyduck · 22nd June 2005, 19:59

Stefan,

As always you provide incredible depth to this forum.

You might want to look at “International underwater cave rescue and recovery.” Web- http://www.iucrr.org/

They have provided a system to recovering divers that have passed on. Included in their system is video and full analysis of the victim at the scene. They take down such things as, depth, time, gas content. I figure that you have seen it already- but I offer it as a thought.

Until you lived the madness, it is hard to reconcile what happens. As other wise people have said “you don’t know what you don’t know.” Unfortunately, I know first hand and I wish that I did not know about this.

I would add that technology were applied properly is incredible it can wash over other people with less experience. We have seen the addition of mixed gas computers, HID lights, better scooters, new batteries (NIMH) more reliable regulators, and plethora of assisted devices. At some point we need to strip the diver down to the basics and build him/her back up from the ground.

The biggest aid I have seen and not too many people add to the equation is “safety divers.” It would be a good to way to bring in new divers to existing groups and provide the newer diver with direct contact with older and more experienced people. I feel that we need to look at our dives and at some point say- ok we are deep enough or moving so far that we need safety implements in place. In Vietnam we saw Search and Rescue teams going after downed pilots- the same thing applies here.

In closing we need to better educate the media and the public in general. I have seen people reporting on these things and they do not have a clue about what they are talking about and that is before the news manager clips the conversation into even less understandable clips. We need to perhaps reach out and ask that we would talk with the media if they are divers or let us write the article. Untimely the weakest link in the chain is the problem- what do we do when that is the diver?

***caveseeker7*** · 22nd June 2005, 20:34

Thanks Andrew.

Quote: (Originally Posted by Crazyduck)

http://www.iucrr.org/ They have provided a system to recovering divers that have passed on. Included in their system is video and full analysis of the victim at the scene. They take down such things as, depth, time, gas content.

You're correct, I'm aware of the very well executed crizzly tasks the IUCRR divers perform.
The only reason that they get to perform them is because of the limited and challenging access inside caves. Well past what any government agency is willing to do to recover divers or their remains. Well past what their insurance carriers will allow them to do.
But this is a very specialized environment.

Rebreather accidents happen anywhere. This year alone, in a pool, a quarry, two lake and the ocean. If I forgot one it's not out of disrespect for the victims, but it has been a bad year so far. Worse yet, I believe we're talking about 4 different countries this year alone. No way that could be standardized.

Let me give you a past example:
CCR diver gets killed on a lake. Lake is part of a National Park, so there is the first jurisdiction. It's also state and county, and the latter provides SAR/R. Already too many involved, and no one knows RBs. Best idea, lets call another manufacturer (in a different state, of course) to have a look at the unit. Luckily they decline for obvious reason, not knowing the unit thoroughly enough and being a competitor. Provide contact and the unit goes off to Panama City for analysis. At least they have the tools and basic knowledge, but the (semi-) public trail stops dead at their gate. In our litigation happy society everybody takes the 5th while liability attorneys have $ signs in their eyes. Unless it actually goes to court, which I doubt, neither the condition the rig was in when analysed nor the findings will be public.

Nad · 22nd June 2005, 22:06

Quote: (Originally Posted by cedricverdier)

Hi all,

We all know Sheck Exley's Accident Analysis that was so useful in decreasing the number of accident in the cave diving community. The idea was to find out the most common factors in the cave diving fatalities. The causes were several times redefined but are pretty much the famous:
- Lack of Training
- Lack of a continuous guideline
- Not enough gas
- Too deep for the mix
- Lack of 3 lights

Obviously that doesn't match with the rebreather diving fatalities that occured in the last few years. It would be great if the rebreather diving community could find a similar list of causes.
Some ideas could also be: Complacency and distraction (cf Tom Mount's last book), exceeding physiological limits (O2, N2, etc), equipment failure...

So what's your list of causes and their order of importance?

Cheers

It could be a good idea.
Have a look at www.ccrb.co.uk, it is the Ouroboros site, on the Our Rebreather button, design fundamentals you can find something useful. It is specially made for Boris from the designer but I think it has many problems included.

Nad

Bear · 23rd June 2005, 00:00

Quote: (Originally Posted by Crazyduck)

The biggest aid I have seen and not too many people add to the equation is “safety divers.” It would be a good to way to bring in new divers to existing groups and provide the newer diver with direct contact with older and more experienced people.

Quite a good point although having been involved with a few trips involving deep dives and pushes, the biggest problem is getting the "safety" diver to fully understand their role and appreciate what they are responsible for. Most seem to have the blinkers on and are looking for some of the "glory" and really want to bypass the "learning" by jumping in and "doing". Technology and advanced knowledge readily available (and possibly better training) has made that easier for people to bypass the "experience" bit.

I had a similar conversation with the person who trained me in OC Trimix on similar issues, especially after Bennet's vertigo during his deep dive and to some extent issues during the dives by Dave Shaw. His take on it was that you need your most experienced people as the support or "safety" team for the divers doing the dive as when things go wrong, you need people with the experience to control or manage the situations as the diver who went to the bottom may be incapacitated and unable to help themselves.

When Jason McHatten had an issue during a dive in Sydney and one of the most experienced divers in the team recognised that Jason had a major problem. Lesser experienced team members may have resulted in a less successful outcome.

For those that may not be aware of the history, I dug around in the archives and found Jason's account: http://www.diveoz.com.au/discussion_...&TOPIC_ID=2567

Cheers

***caveseeker7*** · 23rd June 2005, 03:33

Quote: (Originally Posted by Bear)

... Jason's account ...

From the horses mouth, or the horses arse? is highly recommended reading. Thanks for digging that one out Bear, was looking for it a while ago and couldn't find it.

22nd June 2005, 16:32	#1 (permalink)
cedricverdier S21 M.I.B. Current Rebreather/s: Evolution Megalodon Other Rebreather/s: Not Bought Yet Inspiration Classic Inspiration Vision Sport Kiss Classic Kiss Join Date: Apr 2005 Location: Worldwide! Posts: 497	Rebreather accident analysis Hi all, We all know Sheck Exley's Accident Analysis that was so useful in decreasing the number of accident in the cave diving community. The idea was to find out the most common factors in the cave diving fatalities. The causes were several times redefined but are pretty much the famous: - Lack of Training - Lack of a continuous guideline - Not enough gas - Too deep for the mix - Lack of 3 lights Obviously that doesn't match with the rebreather diving fatalities that occured in the last few years. It would be great if the rebreather diving community could find a similar list of causes. Some ideas could also be: Complacency and distraction (cf Tom Mount's last book), exceeding physiological limits (O2, N2, etc), equipment failure... So what's your list of causes and their order of importance? Cheers __________________ Cedric Verdier PADI Course Director, ANDI-IANTD-PSAI-TDI-DSAT-DAN-NAUI-CMAS Instructor Trainer Trimix (CCR and OC) and Cave Diving Instructor Trainer www.CedricVerdier.com DIRrebreather member
(Offline)

22nd June 2005, 16:56	#2 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,496	Cedric, I believe the biggest problem when it comes to rebreather accidents, fatalities or not, is the analysis itself. Usually, it seriously lacks, evidence is lost or destroyed, hence accurate findings are hard to come by. Therefor answering your question with a high degree of certainty is next to impossible. In addition, actual analysis data is more often than not impossible to access. Madmole has done a commendable job trying to accumulate data on Inspiration fatalities, and there seem to be some common factors. If any or all of them were the actual cause however is hard to determine with the available data. I've discussed the need for guidlines for evidence collection in regards to rebreather accidents with Rob Davie. As a law enforcement officer, public safety diving instructor and rebreather diver/instructor is well aquainted with both evidence collection and rebreather technology. It's a tough nut to crack. When an accident occurs, and the equipment is actually recovered, the gas in the loop is probably the most important evidence there is. How often is gear checked by the diver or a buddy, before the gas can be secured and analyzed? How often the condition of the unit changed - tanks opened or closed, buttons pushed, DSVs opened or closed ... ? To make it even harder, a cmf rebreather would probably need a different protocol than an eCCR. Add to that the myriad of authorities involved, and the fact most no one knows rebreathers, much less specific units, and the task becomes almost impossible. Even if a standard was devised, getting it to everyone involved would be a tall order. To top it all off, some issues like the bodies response to CO2 are not all that well known, vary highly and may be interpreted the wrong way. Look at Iain's excellent post in the Rebreather/heart attack thread. Just my 2¢ __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
(Offline)

22nd June 2005, 19:59	#3 (permalink)
Crazyduck Underwater Mechanic Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2005 Location: TEXAS, Dallas/ Ft.Worth Posts: 712	Stefan, As always you provide incredible depth to this forum. You might want to look at “International underwater cave rescue and recovery.” Web- http://www.iucrr.org/ They have provided a system to recovering divers that have passed on. Included in their system is video and full analysis of the victim at the scene. They take down such things as, depth, time, gas content. I figure that you have seen it already- but I offer it as a thought. Until you lived the madness, it is hard to reconcile what happens. As other wise people have said “you don’t know what you don’t know.” Unfortunately, I know first hand and I wish that I did not know about this. I would add that technology were applied properly is incredible it can wash over other people with less experience. We have seen the addition of mixed gas computers, HID lights, better scooters, new batteries (NIMH) more reliable regulators, and plethora of assisted devices. At some point we need to strip the diver down to the basics and build him/her back up from the ground. The biggest aid I have seen and not too many people add to the equation is “safety divers.” It would be a good to way to bring in new divers to existing groups and provide the newer diver with direct contact with older and more experienced people. I feel that we need to look at our dives and at some point say- ok we are deep enough or moving so far that we need safety implements in place. In Vietnam we saw Search and Rescue teams going after downed pilots- the same thing applies here. In closing we need to better educate the media and the public in general. I have seen people reporting on these things and they do not have a clue about what they are talking about and that is before the news manager clips the conversation into even less understandable clips. We need to perhaps reach out and ask that we would talk with the media if they are divers or let us write the article. Untimely the weakest link in the chain is the problem- what do we do when that is the diver?
(Offline)

22nd June 2005, 20:34	#4 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,496	Thanks Andrew. Quote: (Originally Posted by Crazyduck) http://www.iucrr.org/ They have provided a system to recovering divers that have passed on. Included in their system is video and full analysis of the victim at the scene. They take down such things as, depth, time, gas content. You're correct, I'm aware of the very well executed crizzly tasks the IUCRR divers perform. The only reason that they get to perform them is because of the limited and challenging access inside caves. Well past what any government agency is willing to do to recover divers or their remains. Well past what their insurance carriers will allow them to do. But this is a very specialized environment. Rebreather accidents happen anywhere. This year alone, in a pool, a quarry, two lake and the ocean. If I forgot one it's not out of disrespect for the victims, but it has been a bad year so far. Worse yet, I believe we're talking about 4 different countries this year alone. No way that could be standardized. Let me give you a past example: CCR diver gets killed on a lake. Lake is part of a National Park, so there is the first jurisdiction. It's also state and county, and the latter provides SAR/R. Already too many involved, and no one knows RBs. Best idea, lets call another manufacturer (in a different state, of course) to have a look at the unit. Luckily they decline for obvious reason, not knowing the unit thoroughly enough and being a competitor. Provide contact and the unit goes off to Panama City for analysis. At least they have the tools and basic knowledge, but the (semi-) public trail stops dead at their gate. In our litigation happy society everybody takes the 5th while liability attorneys have $ signs in their eyes. Unless it actually goes to court, which I doubt, neither the condition the rig was in when analysed nor the findings will be public. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
(Offline)

22nd June 2005, 22:06	#5 (permalink)
Nad Rebel to the Bone Current Rebreather/s: Ouroboros Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Other CCR Join Date: Mar 2005 Location: Europe Posts: 980	Quote: (Originally Posted by cedricverdier) Hi all, We all know Sheck Exley's Accident Analysis that was so useful in decreasing the number of accident in the cave diving community. The idea was to find out the most common factors in the cave diving fatalities. The causes were several times redefined but are pretty much the famous: - Lack of Training - Lack of a continuous guideline - Not enough gas - Too deep for the mix - Lack of 3 lights Obviously that doesn't match with the rebreather diving fatalities that occured in the last few years. It would be great if the rebreather diving community could find a similar list of causes. Some ideas could also be: Complacency and distraction (cf Tom Mount's last book), exceeding physiological limits (O2, N2, etc), equipment failure... So what's your list of causes and their order of importance? Cheers It could be a good idea. Have a look at www.ccrb.co.uk, it is the Ouroboros site, on the Our Rebreather button, design fundamentals you can find something useful. It is specially made for Boris from the designer but I think it has many problems included. Nad __________________ The Impossible is often the Untried
(Offline)

23rd June 2005, 00:00	#6 (permalink)
Bear Smelling Dairy Air Current Rebreather/s: Other CCR Dolphin Home Build Not Bought Yet Other Rebreather/s: Other CCR Dolphin Home Build Not Bought Yet Join Date: Apr 2005 Location: Melbourne, Australia Posts: 101	Quote: (Originally Posted by Crazyduck) The biggest aid I have seen and not too many people add to the equation is “safety divers.” It would be a good to way to bring in new divers to existing groups and provide the newer diver with direct contact with older and more experienced people. Quite a good point although having been involved with a few trips involving deep dives and pushes, the biggest problem is getting the "safety" diver to fully understand their role and appreciate what they are responsible for. Most seem to have the blinkers on and are looking for some of the "glory" and really want to bypass the "learning" by jumping in and "doing". Technology and advanced knowledge readily available (and possibly better training) has made that easier for people to bypass the "experience" bit. I had a similar conversation with the person who trained me in OC Trimix on similar issues, especially after Bennet's vertigo during his deep dive and to some extent issues during the dives by Dave Shaw. His take on it was that you need your most experienced people as the support or "safety" team for the divers doing the dive as when things go wrong, you need people with the experience to control or manage the situations as the diver who went to the bottom may be incapacitated and unable to help themselves. When Jason McHatten had an issue during a dive in Sydney and one of the most experienced divers in the team recognised that Jason had a major problem. Lesser experienced team members may have resulted in a less successful outcome. For those that may not be aware of the history, I dug around in the archives and found Jason's account: http://www.diveoz.com.au/discussion_...&TOPIC_ID=2567 Cheers __________________ http://www.victech.org VICTECH.ORG: A web resource for Technical Divers in Victoria
(Offline)

23rd June 2005, 03:33	#7 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,496	Quote: (Originally Posted by Bear) ... Jason's account ... From the horses mouth, or the horses arse? is highly recommended reading. Thanks for digging that one out Bear, was looking for it a while ago and couldn't find it. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
(Offline)

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